Solar cells and solar power systems

Abstract

This application provides a solar cell and a solar power generation system. The solar cell of this application includes: a silicon substrate having a light-receiving surface and a back-lighting surface disposed opposite to each other; a field-effect passivation layer disposed on the light-receiving surface side of the silicon substrate; and a passivation antireflection film disposed on the surface of the field-effect passivation layer opposite to the silicon substrate. The passivation antireflection film includes an interface buffer layer, an oxygen-doped layer, an antireflection layer, and a nitrogen-doped layer stacked sequentially, with the interface buffer layer located between the silicon substrate and the oxygen-doped layer. From the silicon substrate towards the passivation antireflection film, the refractive index of the interface buffer layer, oxygen-doped layer, antireflection layer, and nitrogen-doped layer gradually increases first and then gradually decreases. The solar cell of this application has a low UV decay rate.

Description

Technical Field

[0001] This application relates to the field of solar cells, specifically to a solar cell and a solar power generation system. Background Technology

[0002] Solar cells typically have a passivation antireflection film on the front side. However, in related technologies, the passivation effect of the passivation antireflection film is poor, resulting in an excessively high ultraviolet-induced degradation rate (UV degradation rate) of the solar cell, which reduces the photoelectric conversion efficiency of the solar cell. Summary of the Invention

[0003] This application provides a solar cell with a low UV decay rate.

[0004] A first aspect of this application provides a solar cell, the solar cell comprising: A silicon substrate having a light-receiving surface and a back-lighting surface disposed opposite to each other; A field-effect passivation layer, wherein the field-effect passivation layer is disposed on the light-receiving surface side of the silicon substrate; and A passivation antireflection film is disposed on the surface of the field-effect passivation layer away from the silicon substrate. The passivation antireflection film includes an interface buffer layer, an oxygen-doped layer, an antireflection layer, and a nitrogen-doped layer stacked sequentially. The interface buffer layer is located between the silicon substrate and the oxygen-doped layer. In the direction from the silicon substrate to the passivation antireflection film, the refractive index of the interface buffer layer, the oxygen-doped layer, the antireflection layer, and the nitrogen-doped layer gradually increases first and then gradually decreases.

[0005] Furthermore, the passivation antireflection film also includes a protective layer disposed on the surface of the nitrogen-doped layer opposite to the antireflection layer; from the interface buffer layer to the antireflection layer, the refractive index of the interface buffer layer, the oxygen-doped layer and the antireflection layer gradually increases; from the antireflection layer to the protective layer, the refractive index of the antireflection layer, the nitrogen-doped layer and the protective layer gradually decreases.

[0006] Furthermore, the interface buffer layer satisfies at least one of the following conditions: The interface buffer layer is a hydride oxide layer; The thickness of the interface buffer layer ranges from 1 nm to 3 nm; and The refractive index of the interface buffer layer ranges from 1.65 to 1.75.

[0007] Furthermore, the oxygen-doped layer includes a first oxygen-doped sublayer and a second oxygen-doped sublayer stacked together, the first oxygen-doped sublayer being located between the interface buffer layer and the second oxygen-doped sublayer, and the refractive index of the first oxygen-doped sublayer being less than the refractive index of the second oxygen-doped sublayer.

[0008] Furthermore, the first oxygen-doped sublayer is hydroxysilane oxynitride; the second oxygen-doped sublayer is hydroxysilane oxynitride; the mass fraction of oxygen in the first oxygen-doped sublayer is greater than the mass fraction of oxygen in the second oxygen-doped sublayer, and the mass fraction of nitrogen in the first oxygen-doped sublayer is less than the mass fraction of nitrogen in the second oxygen-doped sublayer.

[0009] Furthermore, the oxygen-doped layer satisfies at least one of the following conditions: The thickness of the oxygen-doped layer ranges from 3 nm to 5 nm; The thickness of the first oxygen-doped sublayer ranges from 1 nm to 3 nm; The refractive index of the first oxygen-doped sublayer ranges from 1.70 to 1.78; The thickness of the second oxygen-doped sublayer ranges from 1 nm to 3 nm; and The refractive index of the second oxygen-doped sublayer ranges from 1.72 to 1.80.

[0010] Furthermore, the antireflection layer includes multiple antireflection sublayers stacked together, with the refractive index of the multiple antireflection sublayers gradually decreasing in the direction from the silicon substrate to the passivation antireflection film.

[0011] Furthermore, the antireflection layer satisfies at least one of the following conditions: All of the multilayer anti-reflection sublayers are silicon nitride layers; The thickness of the antireflective layer ranges from 30 nm to 45 nm; and The multilayer antireflection sublayer includes a first antireflection sublayer, a second antireflection sublayer, and a third antireflection sublayer stacked sequentially. The first antireflection sublayer is located between the oxygen-doped layer and the second antireflection sublayer. The refractive index of the first antireflection sublayer ranges from 2.3 to 2.4. The refractive index of the second antireflection sublayer ranges from 2.2 to 2.3. The refractive index of the third antireflection sublayer ranges from 2.1 to 2.2.

[0012] Furthermore, the nitrogen-doped layer includes a first nitrogen-doped sublayer and a second nitrogen-doped sublayer stacked together, the first nitrogen-doped sublayer being located between the antireflection layer and the second nitrogen-doped sublayer, and the refractive index of the first nitrogen-doped sublayer being greater than the refractive index of the second nitrogen-doped sublayer. Furthermore, the nitrogen-doped layer satisfies at least one of the following conditions: Both the first nitrogen-doped sublayer and the second nitrogen-doped sublayer are hydrides of oxynitride; the mass fraction of oxygen in the first nitrogen-doped sublayer is less than the mass fraction of oxygen in the second nitrogen-doped sublayer, and the mass fraction of nitrogen in the first nitrogen-doped sublayer is greater than the mass fraction of nitrogen in the second nitrogen-doped sublayer; The thickness of the nitrogen-doped layer ranges from 15 nm to 25 nm; The thickness of the first nitrogen-doped sublayer ranges from 8 nm to 13 nm; The refractive index of the first nitrogen-doped sublayer ranges from 1.87 to 1.95; The thickness of the second nitrogen-doped sublayer ranges from 7 nm to 13 nm; and The refractive index of the second nitrogen-doped sublayer ranges from 1.8 to 1.90.

[0013] Furthermore, the protective layer satisfies at least one of the following conditions: The protective layer is a silicon dioxide layer; The thickness of the protective layer ranges from 7 nm to 13 nm; and The refractive index of the protective layer ranges from 1.70 to 1.80.

[0014] A second aspect of this application also provides a solar power generation system, the solar power generation system comprising: The solar cell described in this application embodiment is used to convert light energy into electrical energy; Energy storage device, the energy storage device being used to store the electrical energy; A control system, electrically connected to both the solar cell and the energy storage device, is used to control the solar cell to convert light energy into electrical energy and to control the charging and discharging of the energy storage device; and An inverter is electrically connected to the solar cell, the control system, and the energy storage device. The inverter is used to convert direct current into alternating current under the control of the control system for use by user loads or for connection to the power grid.

[0015] The solar cell described in this application embodiment includes a silicon substrate, a field-effect passivation layer, and a passivation antireflection film. The passivation antireflection film includes an interface buffer layer, an oxygen-doped layer, an antireflection layer, and a nitrogen-doped layer stacked sequentially. The field-effect passivation layer electrochemically passivates the surface of the silicon substrate. The interface buffer layer improves the interfacial stress between the field-effect passivation layer and the oxygen-doped layer, reducing the UV decay rate and potential-induced degradation (PID) rate of the solar cell. Furthermore, the interface buffer layer acts as a UV cutoff layer, blocking high-energy ultraviolet light penetration and reducing the UV decay rate of the solar cell. The oxygen-doped layer allows for a smooth transition of refractive index between the interface buffer layer and the antireflection layer, better reducing interfacial reflection losses in the solar cell, optimizing the interfacial passivation effect of the passivation antireflection film, and reducing interfacial recombination in the solar cell. The antireflection layer passivates internal defects in the solar cell and surface defects in the silicon substrate, providing a stable basis for photoelectric conversion. The nitrogen-doped layer reduces interfacial reflection losses in the solar cell and increases the overall density of the passivation antireflection film, better blocking the penetration of water vapor and metal ions. From the silicon substrate towards the passivation antireflection film, the refractive index of the interface buffer layer, oxygen-doped layer, antireflection layer, and nitrogen-doped layer gradually increases first and then gradually decreases. Through the smooth transition of refractive index between the multiple layers of the passivation antireflection film, interface reflection losses in the solar cell can be better reduced, the interface passivation effect of the passivation antireflection film can be optimized, and interface recombination in the solar cell can be reduced. By coordinating the four layers of the passivation antireflection film in the solar cell and ensuring that the refractive index increases first and then decreases, the conversion efficiency of the solar cell can be improved, and the UV degradation rate and PID degradation rate of the solar panel can be reduced. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the planar structure of a solar cell according to an embodiment of this application.

[0018] Figure 2 The solar cell of the first embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0019] Figure 3 The solar cell of the second embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0020] Figure 4 The solar cell of the third embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0021] Figure 5 The solar cell of the fourth embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0022] Figure 6 The solar cell of the fifth embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0023] Figure 7 The solar cell of the sixth embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0024] Figure 8 The solar cell of the seventh embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0025] Figure 9 The solar cell of the eighth embodiment of this application is along Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0026] Figure 10 The solar cell of the ninth embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure along the AA direction.

[0027] Figure 11 This is a circuit block diagram of a solar power generation system according to an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 100-Solar cell, 10-Silicon substrate, 11-Light-receiving surface, 12-Backlighting surface, 20-Field effect passivation layer, 30-Passivation antireflection film, 31-Interface buffer layer, 32-Oxygen-doped layer, 321-First oxygen-doped sublayer, 322-Second oxygen-doped sublayer, 33-Antireflection layer, 331-Antireflection sublayer, 331a-First antireflection sublayer, 331b-Second antireflection sublayer, 331c-Third antireflection sublayer, 34-Nitrogen-doped layer, 341-First nitrogen-doped sublayer, 342-Second nitrogen-doped sublayer, 35-Protective layer, 40-Boron-doped layer, 50-Front electrode, 60-Tunneling oxide layer, 70-Amorphous silicon layer, 80-Back passivation layer, 90-Back electrode, 200-Solar power generation system, 210-Energy storage device, 220-Control system, 230-Inverter. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0030] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0031] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0032] It should be noted that, for ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0033] Solar cells typically have a passivation antireflection film on the front side. However, in related technologies, the passivation effect of the passivation antireflection film is poor, resulting in an excessively high ultraviolet-induced degradation rate (UV degradation rate) of the solar cell, which reduces the photoelectric conversion efficiency of the solar cell.

[0034] "UV degradation rate" refers to the percentage decrease in output power of a solar cell after prolonged exposure to ultraviolet (UV) radiation.

[0035] Please see Figures 1 to 3This application provides a solar cell 100 (also known as a photovoltaic cell), which includes a silicon substrate 10, a field-effect passivation layer 20, and a passivation antireflection film 30. The silicon substrate 10 has a light-receiving surface 11 and a back-lighting surface 12 disposed opposite to each other; the field-effect passivation layer 20 is disposed on the light-receiving surface 11 side of the silicon substrate 10; the passivation antireflection film 30 is disposed on the surface of the field-effect passivation layer 20 away from the silicon substrate 10, and the passivation antireflection film 30 includes an interface buffer layer 31, an oxygen-doped layer 32, an antireflection layer 33, and a nitrogen-doped layer 34 stacked sequentially, with the interface buffer layer 31 located between the silicon substrate 10 and the oxygen-doped layer 32; in the direction from the silicon substrate 10 to the passivation antireflection film 30, the refractive index of the interface buffer layer 31, the oxygen-doped layer 32, the antireflection layer 33, and the nitrogen-doped layer 34 gradually increases first and then gradually decreases.

[0036] The solar cell 100 of this application embodiment can be applied to a solar power generation system to convert light energy (e.g., solar energy) into electrical energy (direct current).

[0037] Optionally, the solar cell 100 can be, but is not limited to, a TOPCon cell (such as an n-type TOPCon cell or a p-type TOPCon cell). The solar cell 100 can also be referred to as a photovoltaic cell.

[0038] Optionally, the solar cell 100 may be, but is not limited to, at least one of a whole solar cell 100, a half solar cell 100, and a quarter solar cell 100.

[0039] "Whole solar cell" refers to an uncut, complete solar cell. It is in its original form after coming off the solar cell production line.

[0040] A "half-cell solar cell" is a whole solar cell that is laser-cut into two identical halves along a direction perpendicular to the main grid lines.

[0041] A "quadrilateral solar cell" is produced by first cutting a whole solar cell into two halves, and then cutting each half vertically once (or twice) to obtain four solar cell wafers of the same size. Sometimes it also refers to cutting a large G12 solar cell into four wafers.

[0042] Understandably, the silicon substrate 10, the field-effect passivation layer 20, and the passivation antireflection film 30 are stacked sequentially. It is also understood that the silicon substrate 10, the field-effect passivation layer 20, the interface buffer layer 31, the oxygen-doped layer 32, the antireflection layer 33, and the nitrogen-doped layer 34 are stacked sequentially.

[0043] It should be noted that when the solar cell 100 is in use, the light is incident from the light-receiving surface 11.

[0044] The solar cell 100 described in this embodiment includes a silicon substrate 10, a field-effect passivation layer 20, and a passivation antireflection film 30. The passivation antireflection film 30 includes an interface buffer layer 31, an oxygen-doped layer 32, an antireflection layer 33, and a nitrogen-doped layer 34, which are sequentially stacked. The field-effect passivation layer 20 can electrochemically passivate the surface of the silicon substrate 10. The interface buffer layer 31 can improve the interfacial stress between the field-effect passivation layer 20 and the oxygen-doped layer 32, reducing the UV decay rate and potential-induced degradation (PID) rate of the solar cell 100. Furthermore, the interface buffer layer 31 can act as a UV cutoff layer, blocking high-energy ultraviolet light penetration and reducing the UV decay rate of the solar cell 100. The oxygen-doped layer 32 allows for a smooth transition in refractive index between the interface buffer layer 31 and the antireflection layer 33, better reducing interfacial reflection loss of the solar cell 100, optimizing the interfacial passivation effect of the passivation and antireflection film 30, and reducing interfacial recombination of the solar cell 100. The antireflection layer 33 can passivate internal defects of the solar cell 100 and surface defects of the silicon substrate 10, providing a stable basis for photoelectric conversion of the solar cell 100. The nitrogen-doped layer 34 can reduce interfacial reflection loss of the solar cell 100, while increasing the overall density of the passivation and antireflection film 30, better blocking the penetration of water vapor and metal ions. From the silicon substrate 10 toward the passivation antireflection film 30, the refractive indices of the interface buffer layer 31, oxygen-doped layer 32, antireflection layer 33, and nitrogen-doped layer 34 gradually increase and then gradually decrease. Through the smooth transition of refractive indices between the multiple layers of the passivation antireflection film 30, the interface reflection loss of the solar cell 100 can be better reduced, the interface passivation effect of the passivation antireflection film 30 can be optimized, and the interface recombination of the solar cell 100 can be reduced. By coordinating the four layers of the passivation antireflection film 30 of the solar cell 100 and the gradual increase and decrease in refractive index, the conversion efficiency of the solar cell 100 can be improved, and the UV degradation rate and PID degradation rate of the solar panel can be reduced.

[0045] "PID decay rate" refers to the proportion of power loss caused by the potential-induced decay effect.

[0046] Optionally, the silicon substrate 10 may be, but is not limited to, an n-type single-crystal silicon substrate 10.

[0047] Optionally, the resistivity of the silicon substrate 10 ranges from 1.2 Ω·cm to 2.0 Ω·cm; specifically, the resistivity of the silicon substrate 10 can be, but is not limited to, 1.2 Ω·cm, 1.4 Ω·cm, 1.6 Ω·cm, 1.8 Ω·cm, and 2.0 Ω·cm.

[0048] Optionally, the thickness of the silicon substrate 10 ranges from 130 μm to 150 μm. Specifically, the thickness of the silicon substrate 10 can be, but is not limited to, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, etc.

[0049] In the embodiments of this application, when the numerical range a to b is involved, unless otherwise specified, the numerical value can be any value between a and b, including the endpoint value a and the endpoint value b.

[0050] In some embodiments, the field-effect passivation layer 20 can be, but is not limited to, an aluminum oxide layer (Al2O3). The aluminum oxide layer, as the field-effect passivation layer 20, can electrochemically passivate, particularly through field-effect passivation, the surface of the silicon substrate 10. Aluminum oxide (Al2O3) contains a high density of fixed negative charges. These negative charges induce a positive charge layer (i.e., a hole accumulation layer) on the underlying silicon surface. This positive charge layer acts like a "mirror," strongly repelling electrons, which are minority carriers, and preventing them from reaching the surface and recombinating. During the deposition of aluminum oxide, hydrogen atoms saturate the "dangling bonds" (i.e., unpaired electron orbital defects) on the silicon surface, thereby reducing the electron trap state density (Dit) at the interface. Even with a small number of interface defects, the strong field effect can suppress their negative effects.

[0051] Optionally, the thickness of the field-effect passivation layer 20 can be, but is not limited to, 4 nm to 8 nm. Specifically, the thickness of the field-effect passivation layer 20 can be, but is not limited to, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, etc.

[0052] Optionally, the thickness of the passivation antireflection film 30 ranges from 66 nm to 88 nm. Specifically, the thickness of the passivation antireflection film 30 can be, but is not limited to, 66 nm, 68 nm, 70 nm, 73 nm, 75 nm, 78 nm, 80 nm, 83 nm, 85 nm, 88 nm, etc.

[0053] In some embodiments, the interface buffer layer 31 satisfies at least one of the following conditions: The interface buffer layer 31 is a silicon hydride oxide layer (SiO2). x ); The thickness of the interface buffer layer 31 ranges from 1 nm to 3 nm; and The refractive index of the interface buffer layer 31 ranges from 1.65 to 1.75.

[0054] In this embodiment, using hydride silica as the interface buffer layer 31 can better improve the interface stress between the field-effect passivation layer 20 and the oxygen-doped layer 32, reduce the UV decay rate and potential-induced degradation (PID) rate of the solar cell 100. In addition, hydride silica can serve as a UV cutoff layer to block the penetration of high-energy ultraviolet rays, reduce the UV decay rate of the solar cell 100, and provide a stable deposition substrate for the subsequent oxygen-doped layer 32.

[0055] Specifically, the thickness of the interface buffer layer 31 can be, but is not limited to, 1nm, 1.3nm, 1.5nm, 1.8nm, 2nm, 2.3nm, 2.5nm, 2.8nm, 3nm, etc. In this embodiment, if the thickness of the interface buffer layer 31 is too thin, the reduction in UV attenuation rate and PID attenuation rate of the solar cell 100 will not be significant; if the thickness of the interface buffer layer 31 is too thick, it will affect the electron transport of the solar cell 100 and reduce the photoelectric conversion efficiency of the solar cell 100.

[0056] Specifically, the refractive index of the interface buffer layer 31 can be, but is not limited to, 1.65, 1.66, 1.68, 1.70, 1.72, 1.74, 1.75, etc. If the refractive index of the interface buffer layer 31 is too low, the difference in refractive index between the interface buffer layer 31 and the oxygen-doped layer 32 will be too large, which is not conducive to reducing the interface reflection loss of each layer in the passivation antireflection film 30, and is not conducive to improving the photoelectric conversion efficiency of the solar cell 100. If the refractive index of the interface buffer layer 31 is too high, it increases the difficulty of implementing the interface buffer layer 31. When a pure silicon dioxide layer is used as the interface buffer layer 31, it is difficult to achieve an excessively high refractive index.

[0057] Please see Figure 4 In some embodiments, the oxygen-doped layer 32 includes a first oxygen-doped sublayer 321 and a second oxygen-doped sublayer 322 stacked together. The first oxygen-doped sublayer 321 is located between the interface buffer layer 31 and the second oxygen-doped sublayer 322, and the refractive index of the first oxygen-doped sublayer 321 is less than the refractive index of the second oxygen-doped sublayer 322.

[0058] In this embodiment, the oxygen-doped layer 32 includes a first oxygen-doped sublayer 321 and a second oxygen-doped sublayer 322. The first oxygen-doped sublayer 321 is located between the interface buffer layer 31 and the second oxygen-doped sublayer 322, and the refractive index of the first oxygen-doped sublayer 321 is less than that of the second oxygen-doped sublayer 322. This allows the refractive indices of the interface buffer layer 31, the first oxygen-doped sublayer 321, the second oxygen-doped sublayer 322, and the antireflection layer 33 to gradually increase, resulting in a smoother transition, better reduction of interface reflection loss, optimized interface passivation effect, reduced interface recombination, improved photoelectric conversion efficiency of the solar cell 100, and reduced UV and PID attenuation rates of the solar cell 100. Furthermore, it can completely eliminate abrupt changes in refractive index and thermal mismatch between adjacent layers, reduce interface defects and stress, and improve passivation effect and adhesion of each layer.

[0059] In some embodiments, the first oxygen-doped sublayer 321 is hydride oxynitride (SiON). x The second oxygen-doped sublayer 322 is hydride oxynitride (SiON). x The mass fraction of oxygen in the first oxygen-doped sublayer 321 is greater than the mass fraction of oxygen in the second oxygen-doped sublayer 322, and the mass fraction of nitrogen in the first oxygen-doped sublayer 321 is less than the mass fraction of nitrogen in the second oxygen-doped sublayer 322.

[0060] Understandably, both the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322 are mixtures of silicon nitride and silicon oxide.

[0061] In this embodiment, both the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322 are hydrides of silicon oxynitride. By adjusting the ratio of nitrogen to oxygen in the two layers, the refractive indices of the first and second oxygen-doped sublayers 321 and 322 can be effectively adjusted, and they can be continuously deposited on the same coating equipment, simplifying the coating process. The mass fraction of oxygen in the first oxygen-doped sublayer 321 is greater than that in the second oxygen-doped sublayer 322, and the mass fraction of nitrogen in the first oxygen-doped sublayer 321 is less than that in the second oxygen-doped sublayer 322. This results in the refractive index of the first oxygen-doped sublayer 321 being lower than that of the second oxygen-doped sublayer 322. The refractive indices of the interface buffer layer 31, the first oxygen-doped sublayer 321, the second oxygen-doped sublayer 322, and the antireflection layer 33 gradually increase, which can better reduce interface reflection loss, optimize interface passivation, reduce interface recombination, improve the photoelectric conversion efficiency of the solar cell 100, and reduce the UV decay rate and PID decay rate of the solar cell 100. In addition, it can completely eliminate abrupt changes in refractive index and thermal mismatch between adjacent film layers, reduce interface defects and stress, and improve passivation effect and adhesion of each film layer.

[0062] In some embodiments, the oxygen-doped layer 32 satisfies at least one of the following conditions: The thickness of the oxygen-doped layer 32 ranges from 3 nm to 5 nm; The thickness of the first oxygen-doped sublayer 321 ranges from 1 nm to 3 nm; The refractive index of the first oxygen-doped sublayer 321 ranges from 1.70 to 1.78; The thickness of the second oxygen-doped sublayer 322 ranges from 1 nm to 3 nm; and The refractive index of the second oxygen-doped sublayer 322 ranges from 1.72 to 1.80.

[0063] Specifically, the thickness of the oxygen-doped layer 32 can be, but is not limited to, 3nm, 3.3nm, 3.5nm, 3.8nm, 4nm, 4.3nm, 4.5nm, 4.8nm, 5nm, etc. If the thickness of the oxygen-doped layer 32 is too thin, the reduction in UV attenuation rate and PID attenuation rate of the solar cell 100 will not be significant; if the thickness of the oxygen-doped layer 32 is too thick, it will affect the electron transport of the solar cell 100 and reduce the photoelectric conversion efficiency of the solar cell 100.

[0064] Specifically, the thickness of the first oxygen-doped sublayer 321 can be, but is not limited to, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm, 2 nm, 2.3 nm, 2.5 nm, 2.8 nm, 3 nm, etc. When the thickness of the first oxygen-doped sublayer 321 is 1 nm to 3 nm, the photoelectric conversion efficiency of the solar cell 100 can be improved, and the UV decay rate and PID decay rate of the solar cell 100 can be reduced.

[0065] Specifically, the refractive index of the first oxygen-doped sublayer 321 can be, but is not limited to, 1.70, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, etc. If the refractive index of the first oxygen-doped sublayer 321 is too low, the refractive index difference between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322 will be too large, which is not conducive to the smooth transition of the refractive index between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322, not conducive to reducing the interface reflection loss between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322, not conducive to improving the interface passivation effect, and not conducive to reducing interface recombination. If the refractive index of the first oxygen-doped sublayer 321 is too large, the refractive index difference between the interface buffer layer 31 and the first oxygen-doped sublayer 321 will be too large, which is not conducive to the smooth transition of refractive index between the interface buffer layer 31 and the first oxygen-doped sublayer 321, is not conducive to reducing the interface reflection loss between the interface buffer layer 31 and the first oxygen-doped sublayer 321, is not conducive to improving the interface passivation effect, and is not conducive to reducing interface recombination.

[0066] Specifically, the thickness of the second oxygen-doped sublayer 322 can be, but is not limited to, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm, 2 nm, 2.3 nm, 2.5 nm, 2.8 nm, 3 nm, etc. When the thickness of the second oxygen-doped sublayer 322 is 1 nm to 3 nm, the photoelectric conversion efficiency of the solar cell 100 can be improved, and the UV decay rate and PID decay rate of the solar cell 100 can be reduced.

[0067] Specifically, the refractive index of the second oxygen-doped sublayer 322 can be, but is not limited to, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.80, etc. If the refractive index of the second oxygen-doped sublayer 322 is too low, the refractive index difference between the second oxygen-doped sublayer 322 and the antireflection layer 33 will be too large, which is not conducive to the smooth transition of refractive index between the second oxygen-doped sublayer 322 and the antireflection layer 33, not conducive to reducing the interface reflection loss between the second oxygen-doped sublayer 322 and the antireflection layer 33, not conducive to improving the interface passivation effect, and not conducive to reducing interface recombination. If the refractive index of the second oxygen-doped sublayer 322 is too high, the refractive index difference between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322 will be too large, which is not conducive to the smooth transition of the refractive index between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322, is not conducive to reducing the interface reflection loss between the first oxygen-doped sublayer 321 and the second oxygen-doped sublayer 322, is not conducive to improving the interface passivation effect, and is not conducive to reducing interface recombination.

[0068] Please see Figure 5 In some embodiments, the antireflection layer 33 includes multiple antireflection sublayers 331 stacked together, and the refractive index of the multiple antireflection sublayers 331 gradually decreases in the direction from the silicon substrate 10 to the passivation antireflection film 30.

[0069] In this embodiment, the antireflection layer 33 includes multiple antireflection sublayers 331, with the refractive index of the multiple antireflection sublayers 331 gradually decreasing. This can better achieve the antireflection effect on the solar spectrum (e.g., light in the 400nm to 1100nm wavelength range). At the same time, the antireflection layer 33 can passivate defects inside the solar cell 100 and on the surface of the silicon substrate 10, providing a stable basis for photoelectric conversion of the cell.

[0070] In some embodiments, the multilayer anti-reflection sublayers 331 are all silicon nitride layers (SiN). x ).

[0071] In some embodiments, the thickness of the antireflection layer 33 ranges from 30 nm to 45 nm. Specifically, the thickness of the antireflection layer 33 can be, but is not limited to, 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, 40 nm, 42 nm, 44 nm, 45 nm, etc. If the thickness of the antireflection layer 33 is too thin, the passivation effect of the passivation antireflection film 30 is reduced, the UV attenuation rate and PID attenuation rate of the solar cell 100 are reduced, and the reliability of the solar cell 100 is reduced. If the thickness of the antireflection layer 33 is too thick, the light absorption of the solar cell 100 is reduced, resulting in less light absorption by the solar cell 100 and a decrease in the photoelectric conversion efficiency of the solar cell 100.

[0072] Please see Figure 6 In some embodiments, the multilayer antireflection sublayer 331 includes a first antireflection sublayer 331a, a second antireflection sublayer 331b, and a third antireflection sublayer 331c stacked sequentially. The first antireflection sublayer 331a is located between the oxygen-doped layer 32 and the second antireflection sublayer 331b. The refractive index of the first antireflection sublayer 331a ranges from 2.3 to 2.4. The refractive index of the second antireflection sublayer 331b ranges from 2.2 to 2.3. The refractive index of the third antireflection sublayer 331c ranges from 2.1 to 2.2.

[0073] Specifically, the refractive index of the first antireflective sublayer 331a can be, but is not limited to, 2.3, 2.32, 2.34, 2.36, 2.38, 2.4, etc.

[0074] Specifically, the refractive index of the second antireflective sublayer 331b can be, but is not limited to, 2.2, 2.22, 2.24, 2.26, 2.28, 2.3, etc.

[0075] Specifically, the refractive index of the third antireflective sublayer 331c can be, but is not limited to, 2.1, 2.12, 2.14, 2.16, 2.18, 2.2, etc.

[0076] Understandably, the refractive index of the first antireflective sublayer 331a is greater than that of the second antireflective sublayer 331b, and the refractive index of the second antireflective sublayer 331b is greater than that of the third antireflective sublayer 331c.

[0077] In this embodiment, the refractive indices of the first antireflection sublayer 331a, the second antireflection sublayer 331b, and the third antireflection sublayer 331c decrease sequentially, which can better achieve the antireflection effect on the solar spectrum (e.g., light in the 400nm to 1100nm wavelength band). At the same time, the antireflection layer 33 can passivate defects inside the solar cell 100 and on the surface of the silicon substrate 10, providing a stable basis for photoelectric conversion of the cell.

[0078] Please see Figure 7 In some embodiments, the nitrogen-doped layer 34 includes a first nitrogen-doped sublayer 341 and a second nitrogen-doped sublayer 342 stacked together. The first nitrogen-doped sublayer 341 is located between the antireflection layer 33 and the second nitrogen-doped sublayer 342, and the refractive index of the first nitrogen-doped sublayer 341 is greater than the refractive index of the second nitrogen-doped sublayer 342.

[0079] In this embodiment, the nitrogen-doped layer 34 includes a first nitrogen-doped sublayer 341 and a second nitrogen-doped sublayer 342 stacked together. The first nitrogen-doped sublayer 341 is located between the antireflection layer 33 and the second nitrogen-doped sublayer 342, and the refractive index of the first nitrogen-doped sublayer 341 is greater than that of the second nitrogen-doped sublayer 342. This allows the refractive indices of the antireflection layer 33, the first nitrogen-doped sublayer 341, and the second nitrogen-doped sublayer 342 to gradually decrease, resulting in a smoother transition, better reduction of interface reflection loss, optimized interface passivation effect, reduced interface recombination, improved photoelectric conversion efficiency of the solar cell 100, and reduced UV and PID attenuation rates of the solar cell 100. Furthermore, it can completely eliminate abrupt changes in refractive index and thermal mismatch between adjacent layers, reduce interface defects and stress, and improve passivation effect and adhesion of each layer.

[0080] In some embodiments, the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342 are both hydride oxynitride (SiON). x The mass fraction of oxygen in the first nitrogen-doped sublayer 341 is less than the mass fraction of oxygen in the second nitrogen-doped sublayer 342, and the mass fraction of nitrogen in the first nitrogen-doped sublayer 341 is greater than the mass fraction of nitrogen in the second nitrogen-doped sublayer 342.

[0081] Understandably, both the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342 are mixtures of silicon nitride and silicon oxide.

[0082] In this embodiment, both the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342 are hydrides of silicon oxynitride. By adjusting the ratio of nitrogen to oxygen in the two layers, the refractive indices of the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342 can be effectively adjusted, and they can be continuously deposited on the same coating equipment, simplifying the coating process. The mass fraction of oxygen in the first nitrogen-doped sublayer 341 is less than that in the second nitrogen-doped sublayer 342, while the mass fraction of nitrogen in the first nitrogen-doped sublayer 341 is greater than that in the second nitrogen-doped sublayer 342. This results in the refractive index of the first nitrogen-doped sublayer 341 being greater than that of the second nitrogen-doped sublayer 342. The refractive indices of the antireflection layer 33, the first nitrogen-doped sublayer 341, the second nitrogen-doped sublayer 342, and the protective layer gradually decrease, which can better reduce interface reflection loss, optimize interface passivation, reduce interface recombination, improve the photoelectric conversion efficiency of the solar cell 100, and reduce the UV decay rate and PID decay rate of the solar cell 100. In addition, it can completely eliminate abrupt changes in refractive index and thermal mismatch between adjacent film layers, reduce interface defects and stress, and improve passivation effect and adhesion of each film layer.

[0083] In some embodiments, the thickness of the nitrogen-doped layer 34 ranges from 15 nm to 25 nm. Specifically, the thickness of the nitrogen-doped layer 34 can be, but is not limited to, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, etc. If the thickness of the nitrogen-doped layer 34 is too thin, the antireflective coating 30 needs to be thicker to ensure the thickness of the antireflective coating 30, which reduces the conversion efficiency of the solar cell 100. In addition, it reduces the passivation effect of the nitrogen-doped layer 34 and lowers the refractive index of the antireflective coating 30. If the thickness of the nitrogen-doped layer 34 is too thick, it affects the electron transport of the solar cell 100 and reduces the photoelectric conversion efficiency of the solar cell 100.

[0084] In some embodiments, the thickness of the first nitrogen-doped sublayer 341 ranges from 8 nm to 13 nm. Specifically, the thickness of the first nitrogen-doped sublayer 341 can be, but is not limited to, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, 13 nm, etc. If the thickness of the first nitrogen-doped sublayer 341 is too thin, the antireflective coating 30 needs to be thicker to ensure the thickness of the antireflective coating 30, which reduces the conversion efficiency of the solar cell 100. In addition, it reduces the passivation effect of the first nitrogen-doped sublayer 341 and the refractive index of the antireflective coating 30. If the thickness of the first nitrogen-doped sublayer 341 is too thick, it affects the electron transport of the solar cell 100 and reduces the photoelectric conversion efficiency of the solar cell 100.

[0085] In some embodiments, the refractive index of the first nitrogen-doped sublayer 341 ranges from 1.87 to 1.95. Specifically, the refractive index of the first nitrogen-doped sublayer 341 can be, but is not limited to, 1.87, 1.88, 1.89, 1.90, 1.91, 1.92, 1.93, 1.94, 1.95, etc. If the refractive index of the first nitrogen-doped sublayer 341 is too low, the refractive index difference between the antireflection layer 33 and the first nitrogen-doped sublayer 341 will be too large, which is not conducive to the smooth transition of refractive index between the antireflection layer 33 and the first nitrogen-doped sublayer 341, not conducive to reducing the interface reflection loss between the antireflection layer 33 and the first nitrogen-doped sublayer 341, not conducive to improving the interface passivation effect, and not conducive to reducing interface recombination. If the refractive index of the first nitrogen-doped sublayer 341 is too large, the refractive index difference between the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342 will be too large, which is not conducive to the smooth transition of refractive index between the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342, not conducive to reducing the interface reflection loss between the first nitrogen-doped sublayer 341 and the second nitrogen-doped sublayer 342, not conducive to improving the interface passivation effect, and not conducive to reducing interface recombination.

[0086] In some embodiments, the thickness of the second nitrogen-doped sublayer 342 ranges from 7 nm to 13 nm. Specifically, the thickness of the second nitrogen-doped sublayer 342 can be, but is not limited to, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, 13 nm, etc. If the thickness of the second nitrogen-doped sublayer 342 is too thin, the antireflection layer 33 needs to be thicker to ensure the thickness of the passivation antireflection film 30, which reduces the conversion efficiency of the solar cell 100. In addition, it reduces the passivation effect of the second nitrogen-doped sublayer 342 and the refractive index of the passivation antireflection film 30. If the thickness of the second nitrogen-doped sublayer 342 is too thick, it affects the electron transport of the solar cell 100 and reduces the photoelectric conversion efficiency of the solar cell 100.

[0087] In some embodiments, the refractive index of the second nitrogen-doped sublayer 342 ranges from 1.8 to 1.90. Specifically, the refractive index of the second nitrogen-doped sublayer 342 can be, but is not limited to, 1.80, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.90, etc. This can better improve the photoelectric conversion efficiency of the solar cell 100 and reduce the UV decay rate and PID decay rate of the solar cell 100.

[0088] Please see Figure 8 and Figure 9In some embodiments, the passivation antireflection film 30 further includes a protective layer 35 disposed on the surface of the nitrogen-doped layer 34 opposite to the antireflection layer 33; from the interface buffer layer 31 to the antireflection layer 33, the refractive index of the interface buffer layer 31, the oxygen-doped layer 32 and the antireflection layer 33 gradually increases (in other words, increases in a gradient or stepwise manner); from the antireflection layer 33 to the protective layer 35, the refractive index of the antireflection layer 33, the nitrogen-doped layer 34 and the protective layer 35 gradually decreases (in other words, decreases in a gradient or stepwise manner).

[0089] Understandably, in this embodiment, the passivation antireflection film 30 includes the interface buffer layer 31, the oxygen-doped layer 32, the antireflection layer 33, the nitrogen-doped layer 34 and the protective layer 35 stacked sequentially, also known as a five-segment stacked passivation antireflection film 30.

[0090] In this embodiment, a protective layer 35 is provided, and the refractive index of the interface buffer layer 31, the oxygen-doped layer 32, and the antireflection layer 33 gradually increases from the interface buffer layer 31 to the antireflection layer 33; while the refractive index of the antireflection layer 33, the nitrogen-doped layer 34, and the protective layer 35 gradually decreases from the antireflection layer 33 to the protective layer 35. Through the design of the five-layer stacked structure and the refractive index, the reflectivity of the passivation antireflection film 30 can be better reduced, achieving ultra-wideband (300nm to 1100nm) antireflection, increasing the light absorption of the solar cell 100, and improving the photoelectric conversion efficiency of the solar cell 100. Furthermore, it also possesses excellent density, water vapor resistance, and metal ion penetration resistance, which can effectively reduce the PID degradation and light-induced degradation (PID degradation) of the solar cell 100, extending the lifespan of the solar cell 100.

[0091] Optionally, the protective layer 35 is a silicon dioxide layer (SiO2). Using a silicon dioxide layer as the outermost protective layer 35 can better improve the anti-reflection effect of the passivation anti-reflection film 30, reduce the surface reflectivity of the solar cell 100, increase light absorption, and improve the photoelectric conversion efficiency of the solar cell 100. Furthermore, through the synergistic effect of the silicon dioxide protective layer 35 and the silicon nitride anti-reflection layer 33, excellent anti-reflection effects can be achieved over a wider wavelength range. In addition, SiO2 has excellent chemical passivation effects on the surface of the silicon substrate 10. The silicon wafer surface has a large number of dangling bonds, which are recombination centers for photogenerated carriers and can severely reduce cell efficiency. The SiO2 layer can combine with the dangling bonds on the silicon surface, effectively reducing the surface state density and thus reducing carrier recombination losses at the surface. Moreover, as the outermost layer, the SiO2 layer has a certain degree of hardness and chemical stability, which can protect the underlying film layers.

[0092] Optionally, the thickness of the protective layer 35 ranges from 7 nm to 13 nm. Specifically, the thickness of the protective layer 35 can be, but is not limited to, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, etc. If the thickness of the protective layer 35 is too thin, it will be difficult to reduce the reflectivity of light, resulting in increased incident light loss; in addition, it will be difficult to effectively block external impurities or resist plasma damage in subsequent processes, leading to an increase in interface defects, intensified carrier recombination, and a poorer passivation effect. If the thickness of the protective layer 35 is too thick, it will also increase the reflectivity, reduce light absorption, and be detrimental to improving the photoelectric conversion efficiency of the solar cell 100.

[0093] Optionally, the refractive index of the protective layer 35 ranges from 1.70 to 1.80. Specifically, the refractive index of the protective layer 35 can be, but is not limited to, 1.70, 1.72, 1.74, 1.76, 1.78, 1.80, etc. If the refractive index of the protective layer 35 is too low, the protective layer 35 cannot effectively reduce the reflectivity of light, and its mechanical strength is insufficient and it is not durable. If the refractive index of the protective layer 35 is too high, the interference conditions will be destroyed, resulting in a significant increase in the reflectivity of the passivation antireflection film 30. More light that should enter the solar cell 100 will be reflected back, reducing the photoelectric conversion efficiency of the solar cell 100. In addition, when the refractive index is too high, it usually means that the proportion of silicon in the SiO2 film is too high (silicon-rich). This silicon-rich SiO2 layer itself may become a leakage path.

[0094] In one example, the passivation antireflection film 30 includes an interface buffer layer 31 (SiO2) stacked sequentially. x ), oxygen-doped layer 32 (SiONx), antireflection layer 33 (SiNx), nitrogen-doped layer 34 (SiONx), and protective layer 35 (SiO2). x In this embodiment, each of the five film layers includes at least one of nitrogen, silicon, and oxygen. It can be continuously deposited in situ using a single plasma-enhanced chemical vapor deposition (PECVD) process without interruption or furnace change, avoiding interface contamination and increased defects caused by multiple depositions, simplifying process steps, reducing production costs, and improving production efficiency.

[0095] In some embodiments, the passivation antireflection film 30 of this embodiment is prepared by the following steps: placed in a PECVD equipment, the deposition temperature is controlled at 480°C to 530°C (preferably 500°C), and the interface buffer layer 31 (SiO2) is deposited sequentially (continuously) by adjusting the reaction gas flow rate ratio, radio frequency power, deposition gas pressure, and pulse parameters. x), oxygen-doped layer 32 (SiONx), antireflection layer 33 (SiNx), nitrogen-doped layer 34 (SiONx), and protective layer 35 (SiO2). x Before deposition, the PECVD equipment needs to be vacuumed and purged with nitrogen. After deposition, nitrogen purging and natural cooling are performed to ensure the quality of the passivation antireflection film 30.

[0096] Please see Figure 10 In some embodiments, the solar cell 100 further includes a boron doped layer 40, which is disposed between the silicon substrate 10 and the field-effect passivation layer 20. That is, the boron doped layer 40, the field-effect passivation layer 20, and the passivation antireflection film 30 are sequentially stacked on the light-receiving surface 11 of the silicon substrate 10.

[0097] Optionally, the boron-doped layer 40 may be, but is not limited to, a boron-doped polycrystalline silicon layer. Optionally, the thickness of the boron-doped layer 40 may range from 50 nm to 200 nm.

[0098] Please see Figure 10 In some embodiments, the solar cell 100 further includes a front electrode 50 disposed on the surface of the passivation antireflection film 30 opposite to the silicon substrate 10. Understandably, the boron doped layer 40, the field-effect passivation layer 20, the passivation antireflection film 30, and the front electrode 50 are stacked sequentially.

[0099] Optionally, the front electrode 50 can be, but is not limited to, at least one of a silver electrode and a copper electrode.

[0100] Please see Figure 10 In some embodiments, the solar cell 100 further includes a tunneling oxide layer 60, an amorphous silicon layer 70, a back passivation layer 80, and a back electrode 90, which are sequentially stacked on the back surface 12.

[0101] It should be noted that, in some examples, the solar cell 100 includes a back electrode 90, a back passivation layer 80, an amorphous silicon layer 70, a tunneling oxide layer 60, a silicon substrate 10, a boron doped layer 40, a field-effect passivation layer 20, a passivation antireflection film 30, and a front electrode 50, which are stacked sequentially.

[0102] Optionally, the thickness of the tunneling oxide layer 60 ranges from 1.0 nm to 1.5 nm. Specifically, the thickness of the tunneling oxide layer 60 can be, but is not limited to, 1.0 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, etc.

[0103] Optionally, the tunneling oxide layer 60 may be, but is not limited to, a silicon dioxide layer, i.e., SiO2. x .

[0104] Optionally, the thickness of the amorphous silicon layer 70 ranges from 125 nm to 145 nm. Specifically, the thickness of the amorphous silicon layer 70 can be, but is not limited to, 125 nm, 128 nm, 130 nm, 132 nm, 134 nm, 136 nm, 138 nm, 140 nm, 142 nm, 145 nm, etc.

[0105] Optionally, the back passivation layer 80 can be, but is not limited to, a silicon nitride layer, i.e., SiN. x layer.

[0106] Optionally, the back passivation layer 80 has a uniform thickness. The thickness of the back passivation layer 80 ranges from 80 nm to 90 nm. Specifically, the thickness of the back passivation layer 80 can be, but is not limited to, 80 nm, 82 nm, 84 nm, 86 nm, 88 nm, 90 nm, etc. A uniform thickness of the back passivation layer 80 represents a trade-off for optimizing the solar spectrum; furthermore, since silicon nitride is typically deposited across the entire surface via PECVD, uniform thickness simplifies the process; and moreover, uniform thickness ensures consistent hydrogen passivation performance.

[0107] Optionally, the back electrode 90 can be, but is not limited to, at least one of a silver electrode and a copper electrode.

[0108] The solar cell 100 of this application will be further described below through specific embodiments.

[0109] Example 1 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 72 nm; specifically including: 1) By introducing 1800 sccm of SiH4 and 7000 sccm of N2O, adjusting the RF power to 8500 W, the deposition gas pressure to 140 Pa, the power pulse switching ratio to 1:20, and the deposition time to 4 s, a SiO2 layer with a thickness of 2 nm and a refractive index of 1.70 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7000 sccm of N2O, adjusting the RF power to 11000 W, the deposition gas pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 50 s, a SiON layer with a thickness of 5 nm and a refractive index of 1.75 was obtained. x Layer (oxygen-doped layer 32); 3) By introducing 1800 sccm of SiH4 and 5400 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 220 Pa, the power pulse switching ratio to 1:15, and the deposition time to 80 s, a SiN layer with a thickness of 14 nm and a refractive index of 2.35 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:14, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.25. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:13, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.15. x Layer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O. Adjust the RF power to 11000 W, the deposition gas pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 250 s to obtain SiON with a thickness of 25 nm and a refractive index of 1.85. x Layer (nitrogen-doped layer 34); and 5) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN),x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0110] Example 2 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 72 nm; specifically including: 1) By introducing 1800 sccm of SiH4 and 7000 sccm of N2O, adjusting the RF power to 8500 W, the deposition gas pressure to 140 Pa, the power pulse switching ratio to 1:20, and the deposition time to 4 s, a SiO2 layer with a thickness of 2 nm and a refractive index of 1.70 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 20 s, a SiONx layer with a thickness of 2 nm and a refractive index of 1.75 (first oxygen-doped sublayer 321) is obtained. By introducing 1500 sccm of SiH4, 2500 sccm of NH3, and 6500 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 30 s, a SiONx layer with a thickness of 3 nm and a refractive index of 1.80 (second oxygen-doped sublayer 322) is obtained. 3) By introducing 1800 sccm of SiH4 and 5400 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 220 Pa, the power pulse switching ratio to 1:15, and the deposition time to 80 s, a SiN layer with a thickness of 14 nm and a refractive index of 2.35 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:14, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.25. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:13, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.15. x Layer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 8000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 120 s, a SiONx layer with a thickness of 12 nm and a refractive index of 1.88 (first nitrogen-doped sublayer 341) is obtained; by introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 130 s, a SiONx layer with a thickness of 13 nm and a refractive index of 1.85 (second nitrogen-doped sublayer 342) is obtained; and 5) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0111] Example 3 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 82 nm; specifically including: 1) By introducing 1800 sccm of SiH4 and 7000 sccm of N2O, adjusting the RF power to 8500 W, the deposition gas pressure to 140 Pa, the power pulse switching ratio to 1:20, and the deposition time to 4 s, a SiO2 layer with a thickness of 2 nm and a refractive index of 1.70 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7000 sccm of N2O, adjusting the RF power to 11000 W, the deposition gas pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 50 s, a SiON layer with a thickness of 5 nm and a refractive index of 1.75 was obtained. x Layer (oxygen-doped layer 32); 3) By introducing 1800 sccm of SiH4 and 5400 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 220 Pa, the power pulse switching ratio to 1:15, and the deposition time to 80 s, a SiN layer with a thickness of 14 nm and a refractive index of 2.35 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:14, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.25. xLayer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:13, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.15. x Layer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O. Adjust the RF power to 11000 W, the deposition gas pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 250 s to obtain SiON with a thickness of 25 nm and a refractive index of 1.85. x Layer (nitrogen-doped layer 34); after deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; 5) Introduce 1000 sccm of SiH4 and 12000 sccm of N2O, adjust the RF power to 8500W, the deposition gas pressure to 135Pa, the power pulse switching ratio to 1:20, and the deposition time to 150s to obtain SiO2 with a thickness of 10nm and a refractive index of 1.70. x Layer (protective layer 35); and 6) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0112] Example 4 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) The light-receiving surface 11 of the silicon substrate 10 is sequentially subjected to boron diffusion and oxidation to form a boron-doped layer 40, and the back-light surface 12 of the silicon substrate 10 is subjected to borosilicate glass (BSG), and the surface of the boron-doped layer 40 is subjected to RCA cleaning. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 82 nm; specifically including: 1) By introducing 1800 sccm of SiH4 and 7000 sccm of N2O, adjusting the RF power to 8500 W, the deposition gas pressure to 140 Pa, the power pulse switching ratio to 1:20, and the deposition time to 4 s, a SiO2 layer with a thickness of 2 nm and a refractive index of 1.70 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 20 s, a SiONx layer with a thickness of 2 nm and a refractive index of 1.75 (first oxygen-doped sublayer 321) is obtained. By introducing 1500 sccm of SiH4, 2500 sccm of NH3, and 6500 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 30 s, a SiONx layer with a thickness of 3 nm and a refractive index of 1.80 (second oxygen-doped sublayer 322) is obtained. 3) By introducing 1800 sccm of SiH4 and 5400 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 220 Pa, the power pulse switching ratio to 1:15, and the deposition time to 80 s, a SiN layer with a thickness of 14 nm and a refractive index of 2.35 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:14, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.25. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 220 Pa, the power pulse switching ratio was 1:13, and the deposition time was 120 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.15. xLayer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 8000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 120 s, a SiONx layer with a thickness of 12 nm and a refractive index of 1.88 (first nitrogen-doped sublayer 341) is obtained; by introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 130 s, a SiONx layer with a thickness of 13 nm and a refractive index of 1.85 (second nitrogen-doped sublayer 342) is obtained. 5) Introduce 1000 sccm of SiH4 and 12000 sccm of N2O, adjust the RF power to 8500W, the deposition gas pressure to 135Pa, the power pulse switching ratio to 1:20, and the deposition time to 150s to obtain SiO2 with a thickness of 10nm and a refractive index of 1.70. x Layer (protective layer 35); and 6) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0113] Example 5 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 68 nm; specifically including: 1) By introducing 1000 sccm of SiH4 and 4000 sccm of N2O, adjusting the RF power to 8000 W, the deposition gas pressure to 130 Pa, the power pulse switching ratio to 1:20, and the deposition time to 3 s, a SiO2 layer with a thickness of 1 nm and a refractive index of 1.65 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3200 sccm of NH3, and 7200 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 20 s, a SiONx layer with a thickness of 2 nm and a refractive index of 1.73 (first oxygen-doped sublayer 321) is obtained. By introducing 1500 sccm of SiH4, 2600 sccm of NH3, and 6600 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 30 s, a SiONx layer with a thickness of 3 nm and a refractive index of 1.78 (second oxygen-doped sublayer 322) is obtained. 3) By introducing 1800 sccm of SiH4 and 5400 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 200 Pa, the power pulse switching ratio to 1:15, and the deposition time to 50 s, a SiN layer with a thickness of 10 nm and a refractive index of 2.3 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 200 Pa, the power pulse switching ratio was 1:14, and the deposition time was 100 s, resulting in a SiN layer with a thickness of 10 nm and a refractive index of 2.2. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 200 Pa, the power pulse switching ratio was 1:13, and the deposition time was 100 s, resulting in a SiN layer with a thickness of 10 nm and a refractive index of 2.1. xLayer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 10200 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 120 s, a SiONx layer with a thickness of 10 nm and a refractive index of 1.88 (first nitrogen-doped sublayer 341) is obtained; by introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 130 s, a SiONx layer with a thickness of 11 nm and a refractive index of 1.82 (second nitrogen-doped sublayer 342) is obtained. 5) Introduce 1000 sccm of SiH4 and 12000 sccm of N2O, adjust the RF power to 8500W, the deposition gas pressure to 135Pa, the power pulse switching ratio to 1:20, and the deposition time to 140s to obtain SiO2 with a thickness of 10nm and a refractive index of 1.70. x Layer (protective layer 35); and 6) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0114] Example 6 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 130 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 6 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 87 nm; specifically including: 1) By introducing 2500 sccm of SiH4 and 10000 sccm of N2O, adjusting the RF power to 9000W, the deposition gas pressure to 150Pa, the power pulse switching ratio to 1:20, and the deposition time to 5s, a SiO2 layer with a thickness of 3nm and a refractive index of 1.75 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7000 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 20 s, a SiONx layer with a thickness of 2 nm and a refractive index of 1.75 (first oxygen-doped sublayer 321) is obtained. By introducing 1500 sccm of SiH4, 2500 sccm of NH3, and 6500 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 30 s, a SiONx layer with a thickness of 3 nm and a refractive index of 1.80 (second oxygen-doped sublayer 322) is obtained. 3) Introduce 1800 sccm of SiH4 and 5400 sccm of NH3, adjust the RF power to 12000W, the deposition gas pressure to 250Pa, the power pulse switching ratio to 1:15, and the deposition time to 100s to obtain SiN with a thickness of 15nm and a refractive index of 2.4. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 250 Pa, the power pulse switching ratio was 1:14, and the deposition time was 150 s, resulting in a SiN layer with a thickness of 15 nm and a refractive index of 2.3. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9000 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 250 Pa, the power pulse switching ratio was 1:13, and the deposition time was 150 s, resulting in a SiN layer with a thickness of 15 nm and a refractive index of 2.2. xLayer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10500 sccm of N2O. Adjust the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 120 s to obtain a SiONx layer (first nitrogen-doped sublayer 341) with a thickness of 12 nm and a refractive index of 1.90. Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O. Adjust the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 130 s to obtain a SiONx layer (second nitrogen-doped sublayer 342) with a thickness of 13 nm and a refractive index of 1.85. 5) Introduce 1000 sccm of SiH4 and 12000 sccm of N2O, adjust the RF power to 8500W, the deposition gas pressure to 135Pa, the power pulse switching ratio to 1:20, and the deposition time to 140s to obtain SiO2 with a thickness of 10nm and a refractive index of 1.70. x Layer (protective layer 35); and 6) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0115] Example 7 The solar cell 100 in this embodiment is prepared by the following steps: (1) A silicon substrate 10 is provided, the resistivity of the silicon substrate 10 is 1.6 Ω·cm and the thickness is 140 μm, the silicon substrate 10 has a back light surface 12 and a light receiving surface arranged opposite to each other; (2) A boron-doped layer 40 is formed on the light-receiving surface 11 of the silicon substrate 10 by boron diffusion and oxidation, and borosilicate glass (BSG) is applied to the back light-receiving surface 12 of the silicon substrate 10, and the surface of the boron-doped layer 40 is cleaned by RCA. (3) An aluminum oxide layer (field effect passivation layer 20) with a thickness of 5 nm was deposited on the surface of the boron doped layer 40 using atomic layer deposition (ALD) process; (4) Place it in a tubular PECVD equipment, heat it to 500℃, evacuate it to a vacuum degree ≤10Pa, and purge the reaction chamber with 99.999% high-purity nitrogen for 3 minutes to remove impurities, water vapor and residual gas; (5) In-situ continuous deposition of passivation antireflection film 30: The total thickness of passivation antireflection film 30 is 82 nm; specifically including: 1) By introducing 2500 sccm of SiH4 and 11000 sccm of N2O, adjusting the RF power to 9000 W, the deposition gas pressure to 150 Pa, the power pulse switching ratio to 1:20, and the deposition time to 4 s, a SiO2 layer with a thickness of 2 nm and a refractive index of 1.70 was obtained. x Layer (interface buffer layer 31); 2) By introducing 1500 sccm of SiH4, 3000 sccm of NH3, and 7500 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 20 s, a SiONx layer with a thickness of 2 nm and a refractive index of 1.74 (first oxygen-doped sublayer 321) is obtained. By introducing 1500 sccm of SiH4, 2400 sccm of NH3, and 6500 sccm of N2O, adjusting the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 30 s, a SiONx layer with a thickness of 3 nm and a refractive index of 1.79 (second oxygen-doped sublayer 322) is obtained. 3) By introducing 1800 sccm of SiH4 and 5600 sccm of NH3, adjusting the RF power to 12000 W, the deposition gas pressure to 250 Pa, the power pulse switching ratio to 1:15, and the deposition time to 100 s, a SiN layer with a thickness of 14 nm and a refractive index of 2.35 was obtained. x Layer (first antireflection layer 331a); 1800 sccm of SiH4 and 9500 sccm of NH3 were introduced, the RF power was adjusted to 14000 W, the deposition gas pressure was 250 Pa, the power pulse switching ratio was 1:14, and the deposition time was 130 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.25. x Layer (second antireflection layer 331b); 1800 sccm of SiH4 and 9500 sccm of NH3 were introduced, the RF power was adjusted to 16000 W, the deposition gas pressure was 250 Pa, the power pulse switching ratio was 1:13, and the deposition time was 130 s, resulting in a SiN layer with a thickness of 13 nm and a refractive index of 2.15. xLayer (third anti-reflection sublayer 331c); to obtain an anti-reflection layer 33 including a first anti-reflection sublayer 331a, a second anti-reflection sublayer 331b and a third anti-reflection sublayer 331c; 4) Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10500 sccm of N2O. Adjust the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 120 s to obtain a SiONx layer (first nitrogen-doped sublayer 341) with a thickness of 12 nm and a refractive index of 1.90. Introduce 1500 sccm of SiH4, 3000 sccm of NH3, and 10000 sccm of N2O. Adjust the RF power to 11000 W, the deposition pressure to 135 Pa, the power pulse switching ratio to 1:18, and the deposition time to 130 s to obtain a SiONx layer (second nitrogen-doped sublayer 342) with a thickness of 13 nm and a refractive index of 1.85. 5) Introduce 1200 sccm of SiH4 and 12000 sccm of N2O, adjust the RF power to 8500W, the deposition gas pressure to 135Pa, the power pulse switching ratio to 1:20, and the deposition time to 140s to obtain SiO2 with a thickness of 10nm and a refractive index of 1.73. x Layer (protective layer 35); and 6) After deposition, maintain the furnace temperature at 500°C, purge with nitrogen for 5 minutes, and remove after natural cooling to room temperature; (6) A 1.1 nm tunneling oxide layer 60 (SiO2) is sequentially deposited on the back surface 12 of the silicon substrate 10. x ), 135nm amorphous silicon layer 70 and 85nm back passivation layer 80 (SiN), x (layers); and (7) A front silver electrode (front electrode 50) is formed on the surface of the passivation antireflection film 30, and a back silver electrode (back electrode 90) is formed on the surface of the back passivation layer 80; thus, a solar cell 100 is obtained.

[0116] Comparative Example 1 The difference between the solar cell 100 in this comparative example and Example 1 is that the aluminum oxide layer (field effect passivation layer 20) has a thickness of 10 nm and a refractive index of 1.76. The passivation antireflection film 30 includes two silicon nitride layers: the first silicon nitride layer is 20 nm thick and has a refractive index of 2.1, and the second silicon nitride layer is 15 nm thick and has a refractive index of 2.0.

[0117] Comparative Example 2 The difference between the solar cell 100 in this comparative example and Example 1 is that the passivation antireflection film 30 includes three stacked silicon nitride layers. The thickness and refractive index of the three silicon nitride layers, pointing from the silicon substrate 10 toward the passivation antireflection film 30, are successively SiN with a thickness of 14 nm and a refractive index of 2.35. x Layer; SiN with a thickness of 13 nm and a refractive index of 2.25. x Layer, and SiN with a thickness of 13 nm and a refractive index of 2.15. x layer.

[0118] Comparative Example 3 The difference between this comparative example and Example 4 is that the passivation antireflection film 30 in the comparative example is a single layer of SiN. x The passivation antireflection film 30 has a thickness of 60 nm and a refractive index of 2.2.

[0119] The following performance tests were performed on the solar cells 100 of each embodiment and comparative example: (1) Photovoltaic conversion efficiency test: The test was conducted in accordance with the national standard GB / T 6495.1-2025 "Photovoltaic devices - Part 1: Measurement of photovoltaic current-voltage characteristics".

[0120] (2) UV attenuation rate test: The test was conducted in accordance with the national standard GB / T 19394-2025 "Test Method for UV of Photovoltaic Modules".

[0121] (3) PID attenuation rate test: The test was conducted in accordance with the national standard GB / Z 117.101-2026 "Test method for potential-induced attenuation of photovoltaic modules".

[0122] The test results of the solar cells 100 in each embodiment and comparative example are shown in Table 1 below.

[0123] Table 1 Performance parameters of solar cells 100 in each embodiment and comparative example

[0124] As can be seen from the test results of Example 1 and Comparative Examples 1 to 3, compared with Comparative Examples 1 to 3, which use one to three layers of silicon nitride as passivation antireflection film 30, the passivation antireflection film 30 of Example 1 of this application includes an interface buffer layer 31, an oxygen doped layer 32, an antireflection layer 33 and a nitrogen doped layer 34 stacked together. The solar cell 100 of this application has a lower UV decay rate, a lower PID decay rate and a higher photoelectric conversion efficiency.

[0125] As can be seen from the test results of Examples 1 and 2, compared with the scheme of Example 1, the oxygen doping layer 32 of Example 2 includes a first oxygen doping sublayer 321 and a second oxygen doping sublayer 322, and the nitrogen doping layer 34 includes a first nitrogen doping sublayer 341 and a second nitrogen doping sublayer 342. Compared with Example 1, the solar cell 100 of Example 2 has a lower UV decay rate, a lower PID decay rate and a higher photoelectric conversion efficiency.

[0126] As can be seen from the test results of Examples 1 and 3, compared with the scheme of Example 1, the outermost layer of the passivation antireflection film 30 of Example 3 has an added protective layer 35. That is, the passivation antireflection film 30 of Example 3 includes an interface buffer layer 31, an oxygen doping layer 32, an antireflection layer 33, a nitrogen doping layer 34, and a protective layer 35. Compared with Example 1, the solar cell 100 of Example 3 has a lower UV decay rate and a lower PID decay rate, while the photoelectric conversion efficiency of the solar cell 100 is the same.

[0127] The passivation antireflection film 30 of the solar cell 100 in Examples 4 to 7 all include an interface buffer layer 31, an oxygen-doped layer 32, an antireflection layer 33, a nitrogen-doped layer 34, and a protective layer 35 stacked together. The antireflection layer 33 all includes a first antireflection sublayer 331a, a second antireflection sublayer 331b, and a third antireflection sublayer 331c. The oxygen-doped layer 32 all includes a first oxygen-doped sublayer 321 and a second oxygen-doped sublayer 322. The nitrogen-doped layer 34 all includes a first nitrogen-doped sublayer 341 and a second nitrogen-doped sublayer 342. Compared with the schemes of Examples 1 to 3, the solar cell 100 panels of Examples 4 to 7 have lower UV attenuation rate, lower PID attenuation rate, and higher photoelectric conversion efficiency.

[0128] The test results of Examples 1 to 7 and Comparative Examples 1 to 3 show that, compared to Comparative Example 1, which uses one to three layers of silicon nitride as the front antireflection film, the solar cells 100 of Examples 1 to 6 of this application use the passivation antireflection film 30 of this application as the front antireflection film. This can significantly improve the photoelectric conversion efficiency of the solar cell 100, reduce the UV attenuation rate of the solar cell 100, and reduce the PID attenuation rate of the solar cell 100. This is because the passivation antireflection film 30 of this application has better passivation effect and optical matching, thereby better improving the photoelectric conversion efficiency of the solar cell 100 and reducing the UV attenuation rate and PID attenuation rate of the solar cell 100.

[0129] Please see Figure 11This application provides a solar power generation system 200, which includes: a solar cell 100, an energy storage device 210, a control system 220, and an inverter 230, as described in this application embodiment. The solar cell 100 converts light energy into electrical energy; the energy storage device 210 stores the electrical energy; the control system 220 is electrically connected to both the solar cell 100 and the energy storage device 210, and controls the solar cell 100 to convert light energy into electrical energy and controls the energy storage device 210 to charge and discharge; the inverter 230 is electrically connected to the solar cell 100, the control system 220, and the energy storage device 210, and, under the control of the control system 220, converts direct current (DC) into alternating current (AC) for use by user loads or for grid connection.

[0130] Optionally, the user load can be, but is not limited to, industrial equipment (such as machines, production equipment, etc.), household appliances (such as lighting equipment, refrigerators, air conditioners, etc.).

[0131] Optionally, the energy storage device 210 includes one or more individual battery cells. When the energy storage device 210 includes multiple individual battery cells, the multiple individual battery cells are electrically connected. Optionally, the multiple individual battery cells can be connected in parallel, in series, or in a mixed connection. Optionally, the individual battery cells can be, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and this application does not specifically limit them.

[0132] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A solar cell, characterized in that, The solar cell includes: A silicon substrate having a light-receiving surface and a back-lighting surface disposed opposite to each other; A field-effect passivation layer, wherein the field-effect passivation layer is disposed on the light-receiving surface side of the silicon substrate; and A passivation antireflection film is disposed on the surface of the field-effect passivation layer away from the silicon substrate. The passivation antireflection film includes an interface buffer layer, an oxygen-doped layer, an antireflection layer, and a nitrogen-doped layer stacked sequentially. The interface buffer layer is located between the silicon substrate and the oxygen-doped layer. In the direction from the silicon substrate to the passivation antireflection film, the refractive index of the interface buffer layer, the oxygen-doped layer, the antireflection layer, and the nitrogen-doped layer gradually increases first and then gradually decreases.

2. The solar cell according to claim 1, characterized in that, The passivation antireflection film further includes a protective layer disposed on the surface of the nitrogen-doped layer opposite to the antireflection layer; from the interface buffer layer to the antireflection layer, the refractive index of the interface buffer layer, the oxygen-doped layer and the antireflection layer gradually increases; from the antireflection layer to the protective layer, the refractive index of the antireflection layer, the nitrogen-doped layer and the protective layer gradually decreases.

3. The solar cell according to claim 1, characterized in that, The interface buffer layer satisfies at least one of the following conditions: The interface buffer layer is a hydride oxide layer; The thickness of the interface buffer layer ranges from 1 nm to 3 nm; and The refractive index of the interface buffer layer ranges from 1.65 to 1.

75.

4. The solar cell according to claim 1, characterized in that, The oxygen-doped layer includes a first oxygen-doped sublayer and a second oxygen-doped sublayer stacked together. The first oxygen-doped sublayer is located between the interface buffer layer and the second oxygen-doped sublayer, and the refractive index of the first oxygen-doped sublayer is less than the refractive index of the second oxygen-doped sublayer.

5. The solar cell according to claim 4, characterized in that, The first oxygen-doped sublayer is hydroxysilane oxynitride; the second oxygen-doped sublayer is hydroxysilane oxynitride; the mass fraction of oxygen in the first oxygen-doped sublayer is greater than the mass fraction of oxygen in the second oxygen-doped sublayer, and the mass fraction of nitrogen in the first oxygen-doped sublayer is less than the mass fraction of nitrogen in the second oxygen-doped sublayer.

6. The solar cell according to claim 4, characterized in that, The oxygen-doped layer satisfies at least one of the following conditions: The thickness of the oxygen-doped layer ranges from 3 nm to 5 nm; The thickness of the first oxygen-doped sublayer ranges from 1 nm to 3 nm; The refractive index of the first oxygen-doped sublayer ranges from 1.70 to 1.78; The thickness of the second oxygen-doped sublayer ranges from 1 nm to 3 nm; and The refractive index of the second oxygen-doped sublayer ranges from 1.72 to 1.

80.

7. The solar cell according to claim 1, characterized in that, The antireflection layer comprises multiple antireflection sublayers stacked together, with the refractive index of the multiple antireflection sublayers gradually decreasing in the direction from the silicon substrate to the passivation antireflection film.

8. The solar cell according to claim 7, characterized in that, The antireflection layer satisfies at least one of the following conditions: All of the multilayer anti-reflection sublayers are silicon nitride layers; The thickness of the antireflective layer ranges from 30 nm to 45 nm; and The multilayer antireflection sublayer includes a first antireflection sublayer, a second antireflection sublayer, and a third antireflection sublayer stacked sequentially. The first antireflection sublayer is located between the oxygen-doped layer and the second antireflection sublayer. The refractive index of the first antireflection sublayer ranges from 2.3 to 2.

4. The refractive index of the second antireflection sublayer ranges from 2.2 to 2.

3. The refractive index of the third antireflection sublayer ranges from 2.1 to 2.

2.

9. The solar cell according to any one of claims 1-8, characterized in that, The nitrogen-doped layer includes a first nitrogen-doped sublayer and a second nitrogen-doped sublayer stacked together. The first nitrogen-doped sublayer is located between the antireflection layer and the second nitrogen-doped sublayer, and the refractive index of the first nitrogen-doped sublayer is greater than that of the second nitrogen-doped sublayer.

10. The solar cell according to claim 9, characterized in that, The nitrogen-doped layer satisfies at least one of the following conditions: Both the first nitrogen-doped sublayer and the second nitrogen-doped sublayer are hydrides of oxynitride; the mass fraction of oxygen in the first nitrogen-doped sublayer is less than the mass fraction of oxygen in the second nitrogen-doped sublayer, and the mass fraction of nitrogen in the first nitrogen-doped sublayer is greater than the mass fraction of nitrogen in the second nitrogen-doped sublayer; The thickness of the nitrogen-doped layer ranges from 15 nm to 25 nm; The thickness of the first nitrogen-doped sublayer ranges from 8 nm to 13 nm; The refractive index of the first nitrogen-doped sublayer ranges from 1.87 to 1.95; The thickness of the second nitrogen-doped sublayer ranges from 7 nm to 13 nm; and The refractive index of the second nitrogen-doped sublayer ranges from 1.8 to 1.

90.

11. The solar cell according to claim 2, characterized in that, The protective layer satisfies at least one of the following conditions: The protective layer is a silicon dioxide layer; The thickness of the protective layer ranges from 7 nm to 13 nm; and The refractive index of the protective layer ranges from 1.70 to 1.

80.

12. A solar power generation system, characterized in that, The solar power generation system includes: The solar cell according to any one of claims 1-11, wherein the solar cell is used to convert light energy into electrical energy; Energy storage device, the energy storage device being used to store the electrical energy; A control system, electrically connected to both the solar cell and the energy storage device, is used to control the solar cell to convert light energy into electrical energy and to control the charging and discharging of the energy storage device; and An inverter is electrically connected to the solar cell, the control system, and the energy storage device. The inverter is used to convert direct current into alternating current under the control of the control system for use by user loads or for connection to the power grid.

Images