Solar cell and manufacturing method thereof

Abstract

The invention relates to a solar cell and a manufacturing method thereof. The solar cell comprises a first doping layer, a second doping layer and an anti-reflection film which are stacked, wherein the first doping layer is located between the second doping layer and the anti-reflection film; the anti-reflection film comprises a passivation layer, a transition layer and a light-transmitting layer which are stacked, the passivation layer is close to the first doping layer, the transition layer is located between the passivation layer and the light-transmitting layer, the silicon-nitrogen ratio of the passivation layer ranges from 1: 12 to 1: 13, the silicon-nitrogen ratio of the transition layer ranges from 1: 7 to 1: 8, and the silicon-nitrogen ratio of the light-transmitting layer ranges from 1: 10 to 1: 13. According to the solar cell, by arranging the transition layer with the silicon-nitrogen ratio ranging from 1: 7 to 1: 8, the passivation effect of the passivation layer on the first doping layer is improved, and therefore the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a solar cell and a method for manufacturing a solar cell. Background Art

[0002] Solar cells usually include a first doped layer and a second doped layer. When light hits the heterojunction structure formed between the first doped layer and the second doped layer, new holes and electrons are formed. The new holes and electrons can be transferred toward the first doped layer and the second doped layer respectively under the action of the built-in electric field of the heterojunction, thereby forming a potential difference between the first doped layer and the second doped layer, thereby generating electrical energy.

[0003] However, in the prior art, dangling bonds are formed on the surface during the preparation of the first doping layer and the second doping layer, and the dangling bonds interact with newly generated holes and electrons, thereby reducing the photoelectric conversion efficiency of the solar cell. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of this application is to provide a solar cell with improved photoelectric conversion efficiency and a method for manufacturing a solar cell with improved photoelectric conversion efficiency. Specifically, the technical solutions include the following:

[0005] In a first aspect, an embodiment of the present application provides a solar cell, comprising a stacked first doped layer, a second doped layer, and an anti-reflection film, wherein the first doped layer is located between the second doped layer and the anti-reflection film;

[0006] The anti-reflection film includes a passivation layer, a transition layer and a light-transmitting layer which are stacked and bonded together, the passivation layer is close to the first doped layer, and the transition layer is located between the passivation layer and the light-transmitting layer, wherein the silicon-nitrogen ratio of the passivation layer ranges from 1:12 to 1:13, the silicon-nitrogen ratio of the transition layer ranges from 1:7 to 1:8, and the silicon-nitrogen ratio of the light-transmitting layer ranges from 1:10 to 1:13.

[0007] The solar cell of the present application is provided with a stacked first doped layer and a second doped layer so that when light is incident from the side of the first doped layer away from the second doped layer, the first doped layer and the second doped layer can be excited to generate holes and electrons (or electrons and holes) respectively, thereby forming a potential difference between the first doped layer and the second doped layer to generate electrical energy.

[0008] The solar cell of the present application is provided with an anti-reflection film stacked with a passivation layer, a transition layer and a light-transmitting layer, so that light emitted from the outside to the first doped layer can be less reflected by the transition layer and the passivation layer under the action of the light-transmitting layer with a silicon-nitrogen ratio between 1:10 and 1:13, thereby increasing the intensity of light emitted to the first doped layer.

[0009] At the same time, by setting a passivation layer with a silicon-nitrogen ratio between 1:12-1:13, the passivation layer can act on the dangling bonds on the surface of the first doped layer and reduce the number of dangling bonds, thereby achieving a passivation function on the surface of the first doped layer. Then, by setting a transition layer with a silicon-nitrogen ratio between 1:7-1:8, the transition layer can enhance the passivation effect of the passivation layer on the first doped layer, thereby enhancing the photoelectric conversion efficiency of the solar cell of the present application.

[0010] In one embodiment, the thickness of the passivation layer is between 5 nm and 30 nm.

[0011] In this embodiment, a passivation layer with a thickness between 5 nm and 30 nm is provided to ensure the passivation effect of the passivation layer on the surface of the first doping layer.

[0012] In one embodiment, the material of the passivation layer is silicon oxynitride.

[0013] In one embodiment, the transition layer includes a stacked first transition layer and a second transition layer, the first transition layer is located between the second transition layer and the passivation layer, the silicon-nitrogen ratio of the first transition layer ranges from 1:3 to 1:4, and the silicon-nitrogen ratio of the second transition layer ranges from 1:6 to 1:9.

[0014] In this embodiment, a transition layer with a silicon-nitrogen ratio between 1:7 and 1:8 is provided so that the transition layer can enhance the passivation effect of the passivation layer on the first doped layer, thereby enhancing the photoelectric conversion efficiency of the solar cell of the present application.

[0015] On the other hand, by arranging a first transition layer close to the passivation layer and making the silicon-nitrogen ratio of the first transition layer between 1:3-1:4, the first transition layer can enhance the passivation effect of the passivation layer on the first doped layer, thereby enhancing the photoelectric conversion efficiency of the solar cell. Then, by arranging a second transition layer close to the light-transmitting layer and making the silicon-nitrogen ratio of the second transition layer smaller than that of the first transition layer, the reflection of light by the first transition layer is reduced, thereby increasing the intensity of light directed to the first doped layer.

[0016] In one embodiment, the thickness of the first transition layer is between 20 nm and 40 nm, and the thickness of the second transition layer is between 5 nm and 30 nm.

[0017] In this embodiment, a first transition layer with a thickness between 20nm and 40nm is provided to ensure that the first transition layer improves the passivation effect of the passivation layer. At the same time, a second transition layer with a thickness between 5nm and 30nm is provided to ensure that the second transition layer has an effect on the light incident on the first transition layer.

[0018] In one embodiment, the material of the first transition layer is silicon nitride, and the material of the second transition layer is silicon nitride.

[0019] In one embodiment, the light-transmitting layer includes a first light-transmitting layer and a second light-transmitting layer stacked together, the first light-transmitting layer is located between the second light-transmitting layer and the transition layer, the silicon-nitrogen ratio of the first light-transmitting layer ranges from 1:10 to 1:11, and the silicon-nitrogen ratio of the second light-transmitting layer ranges from 1:12 to 1:13.

[0020] In this embodiment, a light-transmitting layer having a silicon-nitrogen ratio between 1:10 and 1:13 is provided so that light emitted from the outside to the first doped layer can be less reflected by the transition layer and the passivation layer under the action of the light-transmitting layer, thereby increasing the intensity of light emitted to the first doped layer.

[0021] On the other hand, by arranging the stacked first light-transmitting layer and the second light-transmitting layer, and making the silicon-nitrogen ratio of the second light-transmitting layer between 1:12-1:13, and the silicon-nitrogen ratio of the first light-transmitting layer between 1:10-1:11, when light is emitted from the outside to the second light-transmitting layer, it can be less reflected by the second light-transmitting layer. At the same time, when light is emitted from the second light-transmitting layer to the first light-transmitting layer, it can also be less reflected by the first light-transmitting layer. Thus, the intensity of light emitted to the first doped layer is increased.

[0022] In one embodiment, the thickness of the first light-transmitting layer is between 20 nm and 40 nm, and the thickness of the second light-transmitting layer is between 20 nm and 40 nm.

[0023] In this embodiment, a first light-transmitting layer with a thickness between 20 nm and 40 nm and a second light-transmitting layer with a thickness between 20 nm and 40 nm are provided to ensure that light directed toward the first doping layer can be less reflected.

[0024] In one embodiment, the material of the first light-transmitting layer is silicon oxynitride, and the material of the second light-transmitting layer is silicon oxide.

[0025] In one embodiment, the anti-reflection film further includes a charged film, and the charged film is located between the passivation layer and the first doped layer.

[0026] In this embodiment, a charged film is provided between the passivation layer and the first doped layer so that the charges in the charged film can cooperate with the passivation layer to act on the dangling bonds on the surface of the first doped layer, thereby reducing the surface recombination rate of the first doped layer, thereby enhancing the passivation effect of the passivation layer on the surface of the first doped layer.

[0027] In one embodiment, the thickness of the anti-reflection film is between 70 nm and 100 nm.

[0028] In this embodiment, the anti-reflection film is provided with a thickness between 70nm and 100nm to avoid affecting the passivation effect of the anti-reflection film on the first doped layer due to too thin thickness, and to avoid affecting the intensity of light emitted from the anti-reflection film to the first doped layer due to too thick thickness.

[0029] In a second aspect, an embodiment of the present application provides a method for manufacturing a solar cell, comprising the following steps:

[0030] manufacturing a stacked first doped layer and a second doped layer;

[0031] A passivation layer, a transition layer and a light-transmitting layer are successively formed on the surface of the first doped layer away from the second doped layer; wherein the silicon-nitrogen ratio of the passivation layer ranges from 1:12 to 1:13, the silicon-nitrogen ratio of the transition layer ranges from 1:7 to 1:8, and the silicon-nitrogen ratio of the light-transmitting layer ranges from 1:10 to 1:13.

[0032] It can be understood that the method for manufacturing a solar cell of the present application can be used to manufacture the solar cell provided in the first aspect above, and the solar cell manufactured by the method has a higher photoelectric conversion efficiency.

[0033] In one embodiment, the passivation layer, the transition layer and the light-transmitting layer are all made by plasma enhanced chemical vapor deposition.

[0034] In one embodiment, when a passivation layer is formed on a surface of the first doped layer away from the second doped layer, the method includes:

[0035] The passivation layer made of silicon oxynitride is produced by using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:13.

[0036] In this embodiment, a passivation layer whose material is silicon oxynitride is prepared by using silane and nitrous oxide in a ratio between 1:12 and 1:13, so that the passivation layer has a higher nitrogen content and enables the electrons in the nitrogen to combine with the dangling bonds on the surface of the first doped layer to achieve passivation of the surface of the first doped layer.

[0037] In one embodiment, when a transition layer is formed on a surface of the first doped layer away from the second doped layer, the process includes:

[0038] A first transition layer made of silicon nitride is formed on a surface of the passivation layer away from the first doping layer using a gas flow ratio of silane to ammonia between 1:3 and 1:4;

[0039] A second transition layer made of silicon nitride is produced on a surface of the first transition layer away from the passivation layer by using a gas flow ratio of silane to ammonia between 1:6 and 1:9.

[0040] In this embodiment, by using silane and ammonia in a ratio between 1:3-1:4 to prepare the first transition layer made of silicon nitride, the hydrogen ions generated during the preparation process can cooperate with the passivation layer, thereby improving the passivation effect on the surface of the first doped layer.

[0041] The second transition layer is then prepared by using silane and ammonia in a ratio between 1:6 and 1:9, so that the silicon-nitrogen ratio of the second transition layer is smaller than that of the first transition layer, thereby reducing the reflection of light from the second transition layer to the first transition layer and increasing the intensity of light directed to the first doped layer.

[0042] In one embodiment, when a light-transmitting layer is formed on a surface of the first doped layer away from the second doped layer, the process includes:

[0043] A first light-transmitting layer made of silicon oxynitride is produced on a surface of the transition layer away from the passivation layer using a gas flow ratio of silane: ammonia: nitrous oxide between 1:1.5:10 and 1:1.5:11;

[0044] The second light-transmitting layer made of silicon oxide is manufactured on the surface of the first light-transmitting layer away from the transition layer by using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:13.

[0045] In this embodiment, a first light-transmitting layer whose material is silicon oxynitride is prepared by using silane, ammonia and nitrous oxide in a ratio between 1:1.5:10 and 1:1.5:11 to reduce the silicon-nitrogen ratio of the first light-transmitting layer and reduce the refractive index of the first light-transmitting layer, thereby increasing the intensity of light passing through the first light-transmitting layer.

[0046] A second light-transmitting layer made of silicon oxide is prepared by using silane and nitrous oxide in a ratio between 1:12 and 1:13, so that the silicon-nitrogen ratio of the second light-transmitting layer is smaller than the silicon-nitrogen ratio of the first light-transmitting layer, thereby reducing the reflection of light emitted from the second light-transmitting layer to the first light-transmitting layer and increasing the intensity of light emitted to the first doped layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a process for manufacturing a solar cell provided in an embodiment of the present application;

[0048] Figure 2 This is a schematic diagram of the structure of a solar cell after step S100 of the solar cell manufacturing method of the present application is completed;

[0049] Figure 3 This is a schematic diagram of the structure of a solar cell after step S200 of the solar cell manufacturing method of the present application is completed;

[0050] Figure 4Another schematic diagram of a process for manufacturing a solar cell provided in an embodiment of the present application;

[0051] Figure 5 A schematic diagram of the structure of a solar cell after step S210 of the solar cell manufacturing method of the present application is completed;

[0052] Figure 6 A schematic diagram of the structure of a solar cell after step S220 of the solar cell manufacturing method of the present application is completed;

[0053] Figure 7 A schematic diagram of the structure of a solar cell after step S230 of the solar cell manufacturing method of the present application is completed;

[0054] Figure 8 A schematic diagram of the structure of a solar cell after step S240 of the solar cell manufacturing method of the present application is completed;

[0055] Fig. 9 A schematic diagram of the structure of a solar cell after step S250 of the solar cell manufacturing method of the present application is completed;

[0056] Fig.10 This is a schematic diagram of the structure of a solar cell after step S300 of the solar cell manufacturing method of the present application is completed;

[0057] Fig.11 A schematic diagram of the structure of a solar cell provided in one embodiment of the present application;

[0058] Fig.12 It is a schematic diagram of the structure of a solar cell in the prior art;

[0059] Fig.13 Another schematic diagram of the structure of a solar cell provided in one embodiment of the present application;

[0060] Fig.14 Another schematic diagram of the structure of a solar cell provided in one embodiment of the present application;

[0061] Fig.15 Another schematic diagram of the structure of a solar cell provided in one embodiment of the present application;

[0062] Fig.16 Another schematic diagram of the structure of a solar cell provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0063] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0064] The following descriptions of the embodiments are with reference to the attached diagrams to illustrate specific embodiments that the present application can be used to implement. The serial numbers for the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, include direct and indirect connections (couplings). The directional terms mentioned in the present application, such as "upper", "lower", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0065] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including", "may include", "include", or "may include" used in this application indicate the existence of the corresponding functions, operations, elements, etc. disclosed, and do not limit one or more other functions, operations, elements, etc. In addition, the terms "including" or "include" indicate the existence of the corresponding features, numbers, steps, operations, elements, components, or combinations thereof disclosed in the specification, and do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, and are intended to cover non-exclusive inclusions.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0067] See also Figure 1 FIG. 1 is a schematic flow chart of a method for manufacturing a solar cell 100 provided in one embodiment of the present application.

[0068] S100, manufacturing a stacked first doping layer 10 and a second doping layer 20;

[0069] For details, please refer to Figure 2 The schematic diagram of the structure of the solar cell 100 after the step S100 of the manufacturing method of the solar cell 100 of the present application is shown. When manufacturing the solar cell 100, a stacked first doping layer 10 and a second doping layer 20 are manufactured so that a heterojunction structure (not shown in the figure) can be formed between the first doping layer 10 and the second doping layer 20.

[0070] Among them, the heterojunction structure can generate new holes and electrons under the action of external light. There is a built-in electric field in the heterojunction structure. It can be understood that the newly generated holes and electrons can be transmitted toward the first doped layer 10 and the second doped layer 20 (or the second doped layer 20 and the first doped layer 10) respectively under the action of the built-in electric field, so that a potential difference is formed between the first doped layer 10 and the second doped layer 20 and electric energy is generated, thereby realizing the photoelectric conversion function of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application.

[0071] S200, a passivation layer 31, a transition layer 32 and a light-transmitting layer 33 are successively formed on the surface of the first doped layer 10 away from the second doped layer 20; wherein the silicon-nitrogen ratio of the passivation layer 31 is in the range of 1:12-1:13, the silicon-nitrogen ratio of the transition layer 32 is in the range of 1:7-1:8, and the silicon-nitrogen ratio of the light-transmitting layer 33 is in the range of 1:10-1:13.

[0072] For details, please refer to Figure 3 The schematic diagram of the structure of the solar cell 100 after the step S200 of the manufacturing method of the solar cell 100 of the present application is shown. When the passivation layer 31 with a silicon-nitrogen ratio between 1:12 and 1:13 is made on the surface of the first doping layer 10 away from the second doping layer 20, the nitrogen element in the passivation layer 31 can provide a large number of electrons, which can combine with the dangling bonds on the surface of the first doping layer 10 to passivate the dangling bonds on the surface of the first doping layer 10, improve the interface quality of the first doping layer 10, and thus realize the passivation effect of the passivation layer 31 on the surface of the first doping layer 10.

[0073] The transition layer 32 is close to the passivation layer 31, and the silicon-nitrogen ratio is between 1:7-1:8. It can be understood that the nitrogen element in the transition layer 32 can also provide a certain number of electrons, which can be combined with the electrons in the passivation layer 31 and the dangling bonds, thereby improving the passivation effect of the passivation layer 31 on the surface of the first doped layer 10, so that the first doped layer 10 has better interface quality. Further, the photoelectric conversion efficiency of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application is improved.

[0074] Since the larger the silicon-nitrogen ratio of the material, the larger the corresponding refractive index of the material, the stronger the material's ability to reflect light. It can be understood that in order to ensure that the transition layer 32 enhances the passivation effect of the passivation layer 31, the silicon-nitrogen ratio of the transition layer 32 is relatively high, and the ability to reflect light is relatively strong. After the passivation layer 31 and the transition layer 32 are manufactured, a light-transmitting layer 33 with a silicon-nitrogen ratio between 1:10 and 1:13 is manufactured, which can increase the intensity of light directed to the transition layer 32, reduce the reflection of light by the transition layer 32, and thus increase the intensity of light directed to the first doped layer 10.

[0075] For the sake of ease of description, the ratios in the description of the silicon-nitrogen ratio in this application are all flow ratios of silicon element and nitrogen element.

[0076] In one embodiment, the passivation layer 31 , the transition layer 32 and the light-transmitting layer 33 are all made by plasma enhanced chemical vapor deposition.

[0077] See also Figure 4 Another schematic flow chart of a method for manufacturing a solar cell 100 provided in one embodiment of the present application is shown.

[0078] After step S100 of “making the stacked first doping layer 10 and the second doping layer 20”, the following steps are included:

[0079] S210, using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:13 to produce a passivation layer 31 made of silicon oxynitride;

[0080] Specifically, for step S210, see Figure 5 The schematic diagram of the structure of the solar cell 100 after the step S210 of the manufacturing method of the solar cell 100 of the present application is shown. In this step, by using silane and nitrous oxide with a ratio between 1:12-1:13 to prepare the passivation layer 31, it can be ensured that the silicon-nitrogen ratio of the passivation layer 31 is between 1:12-1:13.

[0081] Specifically, when the passivation layer 31 is prepared by plasma enhanced chemical vapor deposition, nitrous oxide generates plasma under the action of microwave electrodes, and the plasma reacts with silane to generate the passivation layer 31 made of silicon oxynitride.

[0082] Since the nitrogen content of silane and nitrous oxide is relatively high in the ratio between 1:12-1:13, and the high nitrogen content provides a large number of electrons. It can be understood that the large number of electrons in the large number of nitrogen elements in the passivation layer 31 cooperate with the hydrogen ions to achieve the passivation effect on the dangling bonds on the surface of the first doping layer 10, thereby improving the photoelectric conversion efficiency of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application.

[0083] Since a certain amount of hydrogen ions also exist in the reaction product of silane and nitrous oxide when the passivation layer 31 made of silicon oxynitride is manufactured, these hydrogen ions will diffuse to the surface of the first doped layer 10 and combine with the dangling bonds to achieve a hydrogen passivation effect on the surface of the first doped layer 10. This further improves the photoelectric conversion efficiency of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application.

[0084] On the other hand, since the greater the silicon-nitrogen ratio of silicon oxynitride, the higher the refractive index of the silicon oxynitride film. When the silicon-nitrogen ratio of the passivation layer 31 is too large, the refractive index of the silicon oxynitride material may be too large to reduce the sunlight passing through the silicon oxynitride material, thereby reducing the intensity of light directed to the first doped layer 10. When the silicon-nitrogen ratio of the passivation layer 31 is too small, the passivation effect on the first doped layer 10 will be weakened.

[0085] It can be understood that setting the silicon-nitrogen ratio of the passivation layer 31 between 1:12 and 1:13 can ensure the passivation effect of the passivation layer 31 on the first doped layer 10 while ensuring the intensity of light irradiated to the first doped layer 10 .

[0086] When light passes through the silicon oxynitride material, part of the light will still be absorbed by the silicon oxynitride material. When the passivation layer 31 is prepared by plasma enhanced chemical vapor deposition, the deposition thickness of the passivation layer 31 should be relatively thin. The deposition thickness of the passivation layer 31 should be between 5nm and 30nm. For example, the deposition thickness of the passivation layer 31 is 9nm.

[0087] At the same time, when the passivation layer 31 is prepared by plasma enhanced chemical vapor deposition, in order to ensure that the silicon nitrogen ratio of the passivation layer 31 is between 1:12-1:13, not only is it necessary to limit the gas flow ratio of silane and nitrous oxide required for manufacturing the passivation layer 31 to between 1:12-1:13, but the deposition temperature should also be controlled.

[0088] When the passivation layer 31 is prepared by plasma enhanced chemical vapor deposition, the temperature will also affect the content of silicon atoms in silicon oxynitride, thereby affecting the silicon-nitrogen ratio of the passivation layer 31. The manufacturing method of the solar cell 100 of the present application controls the deposition temperature of the passivation layer 31 between 350°C and 600°C to control the silicon-nitrogen ratio of the passivation layer 31. Exemplarily, the deposition temperature of the passivation layer 31 is 475°C.

[0089] Therefore, the manufacturing method of the solar cell 100 of the present application sets the gas flow ratio of silane and nitrous oxide to 1:12-1:13, and controls the deposition temperature to be between 350° C. and 600° C. to ensure that the silicon-nitrogen ratio of the passivation layer 31 is between 1:12-1:13.

[0090] S220, using a gas flow ratio of silane to ammonia between 1:3 and 1:4 to form a first transition layer 321 made of silicon nitride on the surface of the passivation layer 31 away from the first doping layer 10;

[0091] Specifically, for step S220, see Figure 6 The schematic diagram of the structure of the solar cell 100 after the step S220 of the manufacturing method of the solar cell 100 of the present application is shown. In this step, by using silane and ammonia with a ratio between 1:3-1:4 to prepare the first transition layer 321, it can be ensured that the silicon-nitrogen ratio of the first transition layer 321 is between 1:3-1:4.

[0092] Specifically, when the first transition layer 321 is prepared by plasma enhanced chemical vapor deposition, ammonia generates plasma under the action of microwave electrodes, and the plasma reacts with silane to generate the first transition layer 321 made of silicon nitride.

[0093] Since one ammonia molecule contains three hydrogen atoms and one silane molecule contains four hydrogen atoms, it is understandable that when the first transition layer 321 is prepared using silane and ammonia, the hydrogen elements originally in the silane and ammonia will be released to form a large number of hydrogen ions.

[0094] When making the first transition layer 321, the hydrogen ions generated by the reaction of silane and ammonia can diffuse into the passivation layer 31, merge with the hydrogen ions generated by the passivation layer 31, and then diffuse to the surface of the first doping layer 10, and combine with the dangling bonds on the surface of the first doping layer 10, thereby improving the passivation effect of the passivation layer 31.

[0095] At the same time, the nitrogen element in the first transition layer 321 can also provide a certain number of electrons. It can be understood that the electrons provided by the nitrogen element in the first transition layer 321 can diffuse into the passivation layer 31 to increase the electron content in the passivation layer 31, thereby increasing the number of dangling bonds combined with the electrons.

[0096] Thus, the hydrogen ions generated when the first transition layer 321 is manufactured and the electrons in the nitrogen element can enhance the passivation ability of the passivation layer 31 and enhance the passivation effect of the passivation layer 31 on the first doping layer 10. Furthermore, the photoelectric conversion efficiency of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application is enhanced.

[0097] On the other hand, since the hydrogen ions released during the preparation of the passivation layer 31 mainly come from silane, and the hydrogen ions released during the preparation of the first transition layer 321 also come from ammonia. It can be understood that the passivation function of the passivation layer 31 on the first doped layer 10 mainly comes from the electrons in the nitrogen element, and the improvement of the passivation effect of the first transition layer 321 on the passivation layer 31 mainly comes from the improvement of the hydrogen ion content of the passivation layer 31.

[0098] In order to ensure that the hydrogen ions in the preparation process of the first transition layer 321 enhance the passivation effect of the passivation layer 31, when the first transition layer 321 is prepared by plasma enhanced chemical vapor deposition, the deposition thickness of the first transition layer 321 should be relatively thick. The thickness of the first transition layer 321 should be between 20nm and 40nm. Exemplarily, the deposition thickness of the first transition layer 321 is 20nm.

[0099] At the same time, when the first transition layer 321 is prepared by plasma enhanced chemical vapor deposition, in order to ensure that the silicon nitrogen ratio of the first transition layer 321 is between 1:3-1:4, not only is it necessary to limit the gas flow ratio of silane and ammonia required for manufacturing the first transition layer 321 to between 1:3-1:4, but the deposition temperature should also be controlled.

[0100] Since temperature affects the physicochemical properties of silicon nitride materials, when the temperature rises, the atomic activity and mobility of the substrate surface used to support the silicon nitride material are enhanced, which will reduce the excess silicon atoms in the silicon nitride material, thereby reducing the silicon-nitrogen ratio of the material. The manufacturing method of the solar cell 100 of the present application controls the deposition temperature of the first transition layer 321 between 350°C and 600°C to control the silicon-nitrogen ratio of the first transition layer 321. Exemplarily, the deposition temperature of the first transition layer 321 is between 455°C and 535°C.

[0101] Therefore, the manufacturing method of the solar cell 100 of the present application sets the gas flow ratio of silane and ammonia to 1:3-1:4, and controls the deposition temperature between 350°C and 600°C to ensure that the silicon-nitrogen ratio of the first transition layer 321 is between 1:3-1:4.

[0102] S230, using a gas flow ratio of silane to ammonia between 1:6 and 1:9 to form a second transition layer 322 made of silicon nitride on the surface of the first transition layer 321 away from the passivation layer 31;

[0103] Specifically, for step S230, see Figure 7 The structure schematic diagram of the solar cell 100 after the step S230 of the manufacturing method of the solar cell 100 of the present application is shown. In this step, the second transition layer 322 is formed on the surface of the first transition layer 321 away from the passivation layer 31 using silane and ammonia with a ratio between 1:6 and 1:9, and the silicon-nitrogen ratio of the prepared second transition layer 322 is in the range of 1:6-1:9, so that the silicon-nitrogen ratio of the second transition layer 322 is less than the silicon-nitrogen ratio of the first transition layer 321.

[0104] Specifically, when the second transition layer 322 is prepared by plasma enhanced chemical vapor deposition, ammonia will generate plasma under the action of microwave electrodes, and the plasma will react with silane to generate the second transition layer 322 made of silicon nitride. Since the greater the silicon-nitrogen ratio of the material, the greater the refractive index of the material. Therefore, the refractive index of the second transition layer 322 is less than the refractive index of the first transition layer 321. It can be understood that when light is emitted from the second transition layer 322 to the first transition layer 321, it can be less reflected by the first transition layer 321, thereby increasing the intensity of light passing through the first transition layer 321. Further, the intensity of light emitted to the first doping layer 10 is increased.

[0105] On the other hand, when the second transition layer 322 is made, a large amount of hydrogen ions are also generated, and the second transition layer 322 made of silicon nitride also contains a certain amount of electrons provided by the nitrogen element. It can be understood that the electrons and hydrogen ions in the second transition layer 322 can also diffuse to the passivation layer 31 and merge with the electrons and hydrogen ions in the passivation layer 31, thereby improving the passivation effect of the passivation layer 31 on the surface of the first doped layer 10.

[0106] Since the silicon-nitrogen ratio of the second transition layer 322 is less than that of the first transition layer 321, and greater than that of the light-transmitting layer 33, in order to ensure the intensity of light directed to the first doping layer 10, when the second transition layer 322 is prepared by plasma enhanced chemical vapor deposition, it is necessary to control the deposition thickness of the second transition layer 322. The deposition thickness of the second transition layer 322 ranges from 5 nm to 30 nm. For example, the deposition thickness of the second transition layer 322 is 10 nm.

[0107] At the same time, when the second transition layer 322 is prepared by plasma enhanced chemical vapor deposition, in order to ensure that the silicon nitrogen ratio of the second transition layer 322 is between 1:6-1:9, not only is it necessary to limit the gas flow ratio of silane and ammonia required for manufacturing the second transition layer 322 to between 1:6-1:9, but the deposition temperature should also be controlled.

[0108] Based on the effect of temperature on the silicon-nitrogen ratio of silicon nitride materials, the manufacturing method of the solar cell 100 of the present application controls the deposition temperature of the second transition layer 322 to be between 350°C and 600°C to control the silicon-nitrogen ratio of the second transition layer 322. Exemplarily, the deposition temperature of the second transition layer 322 is between 455°C and 535°C.

[0109] Therefore, the manufacturing method of the solar cell 100 of the present application sets the gas ratio of silane and ammonia to 1:6-1:9, and controls the deposition temperature between 350°C and 600°C to ensure that the silicon-nitrogen ratio of the second transition layer 322 is between 1:6-1:9.

[0110] S240, using a gas flow ratio of silane: ammonia: nitrous oxide between 1:1.5:10 and 1:1.5:11 to form a first light-transmitting layer 331 made of silicon oxynitride on a surface of the transition layer 32 away from the passivation layer 31;

[0111] Specifically, for step S240, see Figure 8 The manufacturing method of the solar cell 100 of the present application is shown as a schematic diagram of the structure of the solar cell 100 after step S240 is completed. In this step, the refractive index of silicon oxynitride is less than the refractive index of silicon nitride. It can be understood that the first light-transmitting layer 331 whose material is silicon oxynitride is prepared by using silane, ammonia and nitrous oxide in a ratio between 1:1.5:10-1:1.5:11, and the silicon-nitrogen ratio of the first light-transmitting layer 331 is between 1:10-1:11. It is possible to reduce the silicon-nitrogen ratio of the first light-transmitting layer 331 and reduce the refractive index of the first light-transmitting layer 331, thereby increasing the intensity of light passing through the first light-transmitting layer 331. Furthermore, the intensity of light directed to the first doping layer 10 is increased.

[0112] Specifically, when the first light-transmitting layer 331 is prepared by plasma-enhanced chemical vapor deposition, ammonia and nitrous oxide will generate plasma under the action of microwave electrodes, and the plasma will react with silane to generate the first light-transmitting layer 331 made of silicon oxynitride. Based on the fact that an ammonia molecule contains one nitrogen atom, and a nitrous oxide molecule contains two nitrogen atoms, it is understandable that setting the ratio of silane, ammonia and nitrous oxide to between 1:1.5:10 and 1:1.5:11 can ensure that when the first light-transmitting layer 331 is generated, the silicon-nitrogen ratio of the first light-transmitting layer 331 is between 1:10 and 1:11.

[0113] On the other hand, since the silicon-nitrogen ratio of the first light-transmitting layer 331 is less than the silicon-nitrogen ratio of the transition layer 32, in order to ensure the intensity of light directed to the first doped layer 10, when the first light-transmitting layer 331 is prepared by plasma enhanced chemical vapor deposition, the deposition thickness of the first light-transmitting layer 331 should be relatively thick. The deposition thickness of the first light-transmitting layer 331 is between 20nm and 40nm. Exemplarily, the deposition thickness of the first light-transmitting layer 331 is 20nm.

[0114] At the same time, when the first light-transmitting layer 331 is prepared by plasma enhanced chemical vapor deposition, in order to ensure that the silicon-nitrogen ratio of the first light-transmitting layer 331 is between 1:10 and 1:11, not only is it necessary to limit the gas flow ratio of silane, ammonia and nitrous oxide required for manufacturing the first light-transmitting layer 331 to 1:1.5:10-1:1.5:11, but it is also necessary to control the deposition temperature of the first light-transmitting layer 331.

[0115] When the first light-transmitting layer 331 is prepared by plasma enhanced chemical vapor deposition, the temperature will also affect the content of silicon atoms in silicon oxynitride, thereby affecting the silicon-nitrogen ratio of the first light-transmitting layer 331. The manufacturing method of the solar cell 100 of the present application controls the deposition temperature of the first light-transmitting layer 331 to be between 350°C and 600°C to control the silicon-nitrogen ratio of the first light-transmitting layer 331. Exemplarily, the deposition temperature of the first light-transmitting layer 331 is between 455°C and 535°C.

[0116] Therefore, the manufacturing method of the solar cell 100 of the present application limits the gas flow ratio of silane, ammonia and nitrous oxide to 1:1.5:10-1:1.5:11, and controls the deposition temperature between 350°C and 600°C to ensure that the silicon-nitrogen ratio of the first light-transmitting layer 331 is between 1:10-1:11.

[0117] S250 , using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:13 to form a second light-transmitting layer 332 made of silicon oxide on the surface of the first light-transmitting layer 331 away from the transition layer 32 .

[0118] Specifically, for step S250, see Fig. 9 The schematic diagram of the structure of the solar cell 100 after the step S250 of the manufacturing method of the solar cell 100 of the present application is shown. In this step, the refractive index of silicon oxide is less than the refractive index of silicon oxynitride. It can be understood that the second light-transmitting layer 332 whose material is silicon oxide is made of silane and nitrous oxide with a ratio between 1:12-1:13, and the silicon-nitrogen ratio of the second light-transmitting layer 332 is between 1:12-1:13. The silicon-nitrogen ratio of the second light-transmitting layer 332 can be reduced to between 1:12-1:13, thereby reducing the refractive index of the second light-transmitting layer 332.

[0119] When light is emitted from the outside to the second light-transmitting layer 332, the light can enter the second light-transmitting layer 332 after less reflection due to the lower refractive index of the second light-transmitting layer 332. The matching arrangement of the first light-transmitting layer 331 and the second light-transmitting layer 332 can reduce the reflection of light emitted from the second light-transmitting layer 332 to the first light-transmitting layer 331.

[0120] Specifically, when the second light-transmitting layer 332 is prepared by plasma-enhanced chemical vapor deposition, nitrous oxide generates plasma under the action of microwave electrodes, and the plasma reacts with silane to generate the second light-transmitting layer 332 made of silicon oxide. Based on the fact that a nitrous oxide molecule contains two nitrogen atoms, it is understandable that the ratio of silane to nitrous oxide is set to between 1:12 and 1:13, which can ensure that when the second light-transmitting layer 332 is generated, the silicon-nitrogen ratio of the second light-transmitting layer 332 is between 1:12 and 1:13.

[0121] On the other hand, the silicon-nitrogen ratio of the material decreases from the transition layer 32 to the light-transmitting layer 33, and the refractive index of the material also decreases from the transition layer 32 to the light-transmitting layer 33. It can be understood that the relative refractive index between the light-transmitting layer 33 and the transition layer 32 is small, and the relative refractive index between the transition layer 32 and the passivation layer 31 is also small, thereby reducing the reflection of the light directed to the transition layer 32 and the passivation layer 31. Further, the intensity of the light directed to the first doping layer 10 is increased.

[0122] On the other hand, since the silicon-nitrogen ratio of the second light-transmitting layer 332 is less than that of the first light-transmitting layer 331, in order to ensure the intensity of light directed to the first doping layer 10, when the second light-transmitting layer 332 is prepared by plasma enhanced chemical vapor deposition, the deposition thickness of the second light-transmitting layer 332 should be relatively thick. The deposition thickness of the second light-transmitting layer 332 is between 20nm and 40nm. Exemplarily, the deposition thickness of the second light-transmitting layer 332 is 32nm.

[0123] At the same time, when the second light-transmitting layer 332 is prepared by plasma enhanced chemical vapor deposition, in order to ensure that the silicon-nitrogen ratio of the second light-transmitting layer 332 is between 1:12-1:13, not only is it necessary to limit the gas flow rate ratio of silane and nitrous oxide required for manufacturing the second light-transmitting layer 332 to 1:12-1:13, but it is also necessary to control the deposition temperature of the second light-transmitting layer 332.

[0124] When the second light-transmitting layer 332 is prepared by plasma enhanced chemical vapor deposition, the temperature will also affect the content of silicon atoms in silicon oxide, thereby affecting the silicon-nitrogen ratio of the second light-transmitting layer 332. The manufacturing method of the solar cell 100 of the present application controls the deposition temperature of the second light-transmitting layer 332 to be between 350°C and 600°C to control the silicon-nitrogen ratio of the second light-transmitting layer 332. Exemplarily, the deposition temperature of the second light-transmitting layer 332 is between 455°C and 535°C.

[0125] Therefore, the manufacturing method of the solar cell 100 of the present application limits the gas flow rate ratio of silane and nitrous oxide to 1:12-1:13, and controls the deposition temperature between 350°C and 600°C to ensure that the silicon-nitrogen ratio of the second light-transmitting layer 332 is between 1:12-1:13.

[0126] In one embodiment, after step S200 of "on the surface of the first doped layer 10 away from the second doped layer 20, a passivation layer 31, a transition layer 32 and a light-transmitting layer 33 are successively formed; wherein the silicon-nitrogen ratio of the transition layer 32 is less than the silicon-nitrogen ratio of the passivation layer 31, and the silicon-nitrogen ratio of the light-transmitting layer 33 is less than the silicon-nitrogen ratio of the transition layer 32", the following steps are also included:

[0127] S300, manufacturing a first electrode 71 conductive with the first doping layer 10 and a second electrode 72 conductive with the second doping layer 20, and extending them outward from a surface of the light-transmitting layer 33 away from the first doping layer 10 and a surface of the second doping layer 20 away from the first doping layer 10 respectively.

[0128] Specifically, for step S300, see Fig.10 The structure diagram of the solar cell 100 after the step S300 of the manufacturing method of the solar cell 100 of the present application is shown. In this step, after the first electrode 71 and the second electrode 72 are manufactured, the light excites the first doping layer 10 and the second doping layer 20 to form a potential difference and generate electrical energy, which can be transmitted outward from the first electrode 71 and the second electrode 72, thereby realizing the discharge function of the solar cell 100 manufactured by the manufacturing method of the solar cell 100 of the present application.

[0129] See also Fig.11 A schematic structural diagram of a solar cell 100 provided in one embodiment of the present application is shown.

[0130] like Fig.11 As shown, the solar cell 100 provided in the present application includes a stacked first doped layer 10, a second doped layer 20 and an anti-reflection film 30, wherein the first doped layer 10 is located between the second doped layer 20 and the anti-reflection film 30. When light is incident from the side provided with the anti-reflection film 30 into the heterojunction structure (not shown in the figure) between the first doped layer 10 and the second doped layer 20, the first doped layer 10 can excite electrons or holes, and correspondingly, the second doped layer 20 can excite holes or electrons.

[0131] The newly generated electrons and holes can be transferred toward the first doping layer 10 and the second doping layer 20 (or the second doping layer 20 and the first doping layer 10) under the action of the built-in battery of the heterojunction structure, thereby forming a potential difference between the first doping layer 10 and the second doping layer 20 and generating electrical energy.

[0132] For ease of description, in this application specification, the first doped layer 10 is defined as an N-type semiconductor layer, and the second doped layer 20 is defined as a P-type semiconductor layer, and the subsequent embodiments are developed based on this structure. It can be understood that in other embodiments, the first doped layer 10 can also be a P-type semiconductor layer, and the second doped layer 20 can also be an N-type semiconductor layer, and the applicant does not make any special restrictions on this.

[0133] At the same time, in this embodiment, the first doped layer 10 set as an N-type semiconductor layer is set as a substrate, so that the solar cell 100 of the present application is an N-type battery. The N-type battery has the advantages of high photoelectric conversion efficiency and long carrier lifetime. It can be understood that setting the first doped layer 10 as an N-type substrate is conducive to improving the photoelectric conversion efficiency of the solar cell 100 of the present application. In other embodiments, the first doped layer 10 or the second doped layer 20 set as a P-type semiconductor layer can also be set as a substrate, and the applicant does not make any special restrictions on this.

[0134] like Fig.11 As shown, the anti-reflection film 30 includes a passivation layer 31, a transition layer 32 and a light-transmitting layer 33 which are stacked and bonded, and the transition layer 32 is located between the passivation layer 31 and the light-transmitting layer 33. When preparing the crystalline silicon used to make the first doping layer 10 and the second doping layer 20, dislocations and grain boundaries are generated on the surface of the crystalline silicon, thereby introducing band energy levels into the crystalline silicon. The dangling bonds in the band energy levels that are positively charged themselves and the dangling bonds that are positively charged due to metal contamination have high recombination activity and can be combined with newly generated electrons flowing to the first doping layer 10, thereby reducing the potential difference between the first doping layer 10 and the second doping layer 20, and reducing the photoelectric conversion efficiency of the solar cell 100.

[0135] The passivation layer 31 contains silicon and nitrogen elements, and the silicon-nitrogen ratio of the passivation layer 31 is between 1:12-1:13, and the nitrogen element can provide electrons for the passivation layer 31. It can be understood that the electrons in the nitrogen element can combine with the dangling bonds on the surface of the first doping layer 10 to passivate the dangling bonds. The passivated dangling bonds have a lower recombination activity, so that the newly generated electrons flowing to the first doping layer 10 are difficult to interact with the passivated dangling bonds, thereby increasing the potential difference between the first doping layer 10 and the second doping layer 20, and improving the photoelectric conversion efficiency.

[0136] The transition layer 32 is arranged on the surface of the passivation layer 31 away from the first doping layer 10, and the silicon-nitrogen ratio of the transition layer 32 is in the range of 1:7-1:8. It can be understood that the transition layer 32 also has a certain nitrogen content, so that the nitrogen in the transition layer 32 can also provide a certain number of electrons, and the electrons can diffuse into the passivation layer 31 to increase the electron concentration in the passivation layer 31, thereby increasing the number of electrons in the passivation layer 31 for passivating the dangling bonds, and improving the passivation effect of the passivation layer 31 on the first doping layer 10. In turn, the photoelectric conversion efficiency of the solar cell 100 of the present application is improved.

[0137] In order to ensure the improvement of the passivation effect of the passivation layer 31, it is necessary to ensure that the transition layer 32 has a certain thickness. The refractive index of the transition layer 32 is relatively high, and the reflection ability of light is relatively strong. It can be understood that the setting of the light-transmitting layer 33 with a silicon-nitrogen ratio ranging from 1:10 to 1:13 can reduce the relative refractive index of the transition layer 32 relative to the light-transmitting layer 33, so as to reduce the reflection of light by the transition layer 32 and the passivation layer 31, thereby improving the intensity of light directed to the first doped layer 10.

[0138] Therefore, the solar cell 100 of the present application sets a transition layer 32 with a silicon-nitrogen ratio between 1:7 and 1:8 to improve the passivation effect of the passivation layer 31 on the first doped layer 10 while ensuring the intensity of light incident on the first doped layer 10, thereby improving the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0139] See also Fig.12 FIG. 1 is a schematic structural diagram of a solar cell 100 ′ in the prior art.

[0140] like Fig.12As shown, in the prior art, a solar cell 100' comprises a first doped layer 10', a second doped layer 20', a first electrode 31' and a second electrode 32'. The first doped layer 10' and the second doped layer 20' are stacked on each other, and a heterojunction structure (not shown in the figure) is formed therebetween. When light is directed to the heterojunction structure, electrons and holes are generated in the heterojunction structure, and the newly generated electrons and holes can be respectively transmitted to the first doped layer 10' and the second doped layer 20' under the action of the built-in electric field of the heterojunction structure, thereby forming a potential difference between the first doped layer 10' and the second doped layer 20', and generating electric energy.

[0141] The first electrode 31' is connected to the first doped layer 10', and the second electrode 32' is connected to the second doped layer 20'. When electric energy is generated between the first doped layer 10' and the second doped layer 20', the first electrode 31' and the second electrode 32' transmit the current to the outside to realize the discharge function of the solar cell 100'.

[0142] In the prior art, since the surfaces of the first doped layer 10' and the second doped layer 20' have a large number of dangling bonds, these dangling bonds will react with newly generated electrons and holes, thereby reducing the number of carriers transmitted to the first doped layer 10' and the second doped layer 20', thereby reducing the potential difference between the first doped layer 10' and the second doped layer 20', thereby making the photoelectric conversion efficiency of the solar cell 100' relatively low.

[0143] In the prior art, when using Fig.12 In the structure of the solar cell 100' shown, the photoelectric conversion efficiency of the solar cell 100' for sunlight is between 24.3% and 24.5%. In the structure of the solar cell 100 of the present application, the anti-reflection film 30 of the present application is provided to improve the photoelectric conversion efficiency of the solar cell 100 of the present application, and the photoelectric conversion efficiency of the solar cell 100 of the present application can be improved by 0.1% to 0.2%.

[0144] Therefore, the solar cell 100 of the present application is provided with an anti-reflection film 30 on the surface of the first doped layer 10 away from the second doped layer 20, and a transition layer 32 with a silicon-nitrogen ratio between the passivation layer 31 and the light-transmitting layer 33 is provided in the anti-reflection film 30, so that when the passivation layer 31 passivates the dangling bonds on the surface of the first doped layer 10, the transition layer 32 can enhance the passivation effect of the passivation layer 31 on the surface of the first doped layer 10, thereby enhancing the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0145] In one embodiment, please refer to Fig.11The solar cell 100 provided in the present application further includes a first electrode 71 and a second electrode 72. The first electrode 71 is electrically connected to the first doped layer 10 and extends outward from the surface of the anti-reflection film 30 away from the first doped layer 10. The second electrode 72 is electrically connected to the second doped layer 20 and extends outward from the surface of the second doped layer 20 away from the first doped layer 10.

[0146] It can be understood that when light is irradiated onto the heterojunction structure between the first doping layer 10 and the second doping layer 20 and a potential difference is generated between the first doping layer 10 and the second doping layer 20, current can be transmitted outward from the first electrode 71 and the second electrode 72, thereby realizing the discharge function of the solar cell 100 of the present application.

[0147] See also Fig.13 Another structural schematic diagram of a solar cell 100 provided in one embodiment of the present application is shown.

[0148] like Fig.13 As shown, the anti-reflection film 30 can also be arranged on the surface of the second doped layer 20 away from the first doped layer 10, and the passivation layer 31 is located between the transition layer 32 and the second doped layer 20. The second doped layer 20 is also specified in the present application to be made of crystalline silicon. It can be understood that the surface of the second doped layer 20 close to the passivation layer 31 also has dangling bonds. Therefore, the provision of the passivation layer 31 can also passivate the surface of the second doped layer 20. At the same time, the provision of the transition layer 32 can also enhance the passivation effect of the passivation layer 31 on the second doped layer 20, thereby enhancing the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0149] When light is emitted from the side of the first doping layer 10 facing away from the second doping layer 20 toward the first doping layer 10 , part of the light will pass through the first doping layer 10 and the second doping layer 20 and emit toward the surface of the anti-reflection film 30 .

[0150] Based on the silicon-nitrogen ratio of the passivation layer 31 being between 1:12-1:13, and the silicon-nitrogen ratio of the transition layer 32 being between 1:7-1:8, it can be understood that the transition layer 32 has a strong reflective ability to light, and can make the light emitted from the second doping layer 20 to the surface of the transition layer 32 be reflected to the heterojunction structure between the first doping layer 10 and the second doping layer 20, thereby increasing the intensity of the light emitted to the heterojunction structure. Further, the electric energy generated by the solar cell 100 of the present application is improved.

[0151] See also Fig.14 Another structural schematic diagram of a solar cell 100 provided in one embodiment of the present application is shown.

[0152] like Fig.14As shown, the transition layer 32 includes a stacked first transition layer 321 and a second transition layer 322, and the first transition layer 321 is located between the second transition layer 322 and the passivation layer 31. The silicon-nitrogen ratio of the first transition layer 321 is between 1:3 and 1:4, so that the electrons in the nitrogen element in the first transition layer 321 can diffuse into the passivation layer 31, so as to increase the number of electrons in the passivation layer 31, thereby increasing the number of electrons in the passivation layer 31 for passivating the dangling bonds, and improving the passivation effect of the passivation layer 31 on the first doped layer 10. This improves the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0153] The silicon-nitrogen ratio of the second transition layer 322 is in the range of 1:6-1:9, which corresponds to the refractive index of the second transition layer 322 being less than the refractive index of the first transition layer 321. It can be understood that the second transition layer 322 is arranged close to the light-transmitting layer 33, so as to reduce the reflection of the light by the first transition layer 321, thereby increasing the intensity of the light directed to the first doping layer 10.

[0154] On the other hand, the nitrogen element in the second transition layer 322 can also provide a certain number of electrons, and allow these electrons to diffuse into the first transition layer 321, so as to cooperate with the electrons in the first transition layer 321 to increase the number of electrons in the passivation layer 31, thereby increasing the number of electrons in the passivation layer 31 for passivating dangling bonds, and improving the passivation effect of the passivation layer 31 on the first doping layer 10. This further improves the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0155] At the same time, the silicon-nitrogen ratio of the first transition layer 321 is set between 1:3-1:4, and the silicon-nitrogen ratio of the second transition layer 322 is set between 1:6-1:9, so that the overall silicon-nitrogen ratio of the transition layer 32 is between 1:7-1:8, thereby ensuring that the passivation effect of the transition layer 32 on the passivation layer 31 is improved.

[0156] See also Fig.15 Another structural schematic diagram of a solar cell 100 provided in one embodiment of the present application is shown.

[0157] like Fig.15 As shown, the light-transmitting layer 33 includes a first light-transmitting layer 331 and a second light-transmitting layer 332 stacked, and the first light-transmitting layer 331 is located between the second light-transmitting layer 332 and the transition layer 32. The silicon-nitrogen ratio of the first light-transmitting layer 331 is in the range of 1:10-1:11, and the silicon-nitrogen ratio of the second light-transmitting layer 332 is in the range of 1:12-1:13. When light is emitted from the outside to the second light-transmitting layer 332, the second light-transmitting layer 332 has a relatively small refractive index, and the light can be emitted into the second light-transmitting layer 332 after less reflection.

[0158] When the light is emitted from the second light-transmitting layer 332 to the first light-transmitting layer 331 , the relative refractive index of the second light-transmitting layer 332 is smaller than that of the first light-transmitting layer 331 , and the light can enter the first light-transmitting layer 331 after less reflection and emit to the transition layer 32 .

[0159] It can be understood that the external light can be less reflected by the first light-transmitting layer 331 and the second light-transmitting layer 332 under the cooperation of the first light-transmitting layer 331 and the second light-transmitting layer 332, thereby increasing the intensity of the light emitted to the transition layer 32. At the same time, the setting of the refractive index of the first light-transmitting layer 331 and the second light-transmitting layer 332 can also reduce the relative refractive index of the transition layer 32 and the passivation layer 31, thereby increasing the intensity of the light emitted to the first doping layer 10.

[0160] At the same time, the silicon-nitrogen ratio of the first light-transmitting layer 331 is set between 1:10-1:11, and the silicon-nitrogen ratio of the second light-transmitting layer 332 is set between 1:12-1:13, so that the overall silicon-nitrogen ratio of the light-transmitting layer 33 is between 1:10-1:13, thereby ensuring the intensity of light directed to the first doped layer 10.

[0161] See also Fig.16 Another structural schematic diagram of a solar cell 100 provided in one embodiment of the present application is shown.

[0162] like Fig.16 As shown, the anti-reflection film 30 further includes a charged film 34, which is located between the passivation layer 31 and the first doped layer 10. The charges in the charged film 34 can combine with the electrons in the passivation layer 31 without damaging the silicon substrate of the first doped layer 10, and combine with the dangling bonds on the surface of the first doped layer 10, thereby reducing the surface recombination rate of the first doped layer 10, thereby improving the passivation effect of the passivation layer 31 on the surface of the first doped layer 10.

[0163] On the other hand, metal elements are added to the charged film 34 , which can be combined with the metallization paste forming the first electrode 71 to enhance the contact effect between the first doping layer 10 and the first electrode 71 .

[0164] In one embodiment, the thickness of the charged film 34 is between 4 nm and 10 nm. Exemplarily, the thickness of the charged film 34 is 4 nm.

[0165] In one embodiment, the material of the charged film 34 may be one or more of aluminum oxide, silicon dioxide, and zinc oxide.

[0166] In one embodiment, the thickness of the anti-reflection film 30 is between 70nm and 100nm. When the thickness of the anti-reflection film 30 is greater than 100nm, the refractive index of the anti-reflection film 30 is relatively large, so that the intensity of the light directed to the first doping layer 10 is relatively weak, which may cause the electric field formed between the first doping layer 10 and the second doping layer 20 to be difficult to offset the effect of the barrier electric field, so that the first doping layer 10 and the second doping layer 20 cannot form a potential difference, thereby affecting the photoelectric conversion function of the solar cell 100 of the present application.

[0167] When the thickness of the anti-reflection film 30 is less than 70 nm, in order to ensure the intensity of light directed toward the first doped layer 10 , the passivation layer 31 and the transition layer 32 will also be relatively thin, thereby affecting the passivation effect of the anti-reflection film 30 on the first doped layer 10 .

[0168] Therefore, by providing the anti-reflection film 30 with a thickness between 70 nm and 100 nm, the passivation effect of the anti-reflection film 30 on the first doped layer 10 can be ensured while also ensuring the intensity of light incident on the surface of the first doped layer 10 .

[0169] In one embodiment, please refer to Fig.11 The solar cell 100 of the present application further includes a protective layer 40, which is disposed between the first doped layer 10 and the anti-reflection film 30. The protective layer 40 is used to protect the first doped layer 10 to prevent external impurities from reacting with the first doped layer 10, thereby affecting the quality of the first doped layer 10.

[0170] In one embodiment, if Fig.11 As shown, the solar cell 100 of the present application further includes a diffusion layer 50, which is disposed between the protective layer 40 and the first doping layer 10. The doping concentration in the first doping layer 10 is relatively high. It can be understood that the diffusion layer 50 is disposed so that the doping elements in the first doping layer 10 can diffuse into the diffusion layer 50, so that the doping concentration between the first doping layer 10 and the protective layer 40 presents a gradient change, so as to reduce the mismatch lattice on the surface of the first doping layer 10.

[0171] In one embodiment, if Fig.11As shown, the solar cell 100 of the present application further includes a tunneling layer 60, which is located between the first doping layer 10 and the second doping layer 20. The tunneling layer 60 can prevent holes from entering the first doping layer 10 while ensuring that the newly generated electrons of the heterojunction structure can enter the first doping layer 10. When light excites the heterojunction structure to generate electrons and holes, some holes will enter the first doping layer 10 along with the electrons. It can be understood that the holes entering the first doping layer 10 may recombine with the newly generated electrons, thereby reducing the number of newly generated electrons in the first doping layer 10 and reducing the potential difference between the first doping layer 10 and the second doping layer 20.

[0172] Thus, the setting of the tunneling layer 60 can block the holes generated by the heterojunction structure on the side close to the second doping layer 20, and will not affect the electrons generated by the heterojunction structure to pass through the tunneling layer 60 and enter the first doping layer 10. It can be understood that the tunneling layer 60 blocks the path of the holes generated by the heterojunction structure to be transmitted to the first doping layer 10. This avoids the situation where the newly generated holes enter the first doping layer 10, and further improves the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0173] The following is a comparative description of the beneficial effects that may be achieved by the method of the present application, in combination with three possible embodiments (Embodiment 1, Embodiment 2, and Embodiment 3) of the solar cell 100 of the present application and two typical embodiments in the prior art (Comparative Example 1 and Comparative Example 2):

[0174] Example 1

[0175] A solar cell 100 is provided, comprising a stacked first doping layer 10, a second doping layer 20 and an anti-reflection film 30, wherein the first doping layer 10 is located between the second doping layer 20 and the anti-reflection film 30. The first doping layer 10 is an N-type substrate.

[0176] The anti-reflection film 30 includes a passivation layer 31, a transition layer 32 and a light-transmitting layer 33 which are stacked and bonded, and the passivation layer 31 is located between the first doping layer 10 and the transition layer 32. The silicon-nitrogen ratio of the passivation layer 31 is 1:12, and the thickness is 20nm; the silicon-nitrogen ratio of the transition layer 32 is 1:7, and the thickness is 40nm; the silicon-nitrogen ratio of the light-transmitting layer 33 is 1:10, and the thickness is 40nm.

[0177] Example 2

[0178] A solar cell 100 is provided, comprising a stacked first doping layer 10, a second doping layer 20 and an anti-reflection film 30, wherein the first doping layer 10 is located between the second doping layer 20 and the anti-reflection film 30. The first doping layer 10 is an N-type substrate.

[0179] The anti-reflection film 30 includes a stacked and bonded passivation layer 31, a first transition layer 321, a second transition layer 322, a first light-transmitting layer 331, and a second light-transmitting layer 332, and the passivation layer 31 is located between the first doping layer 10 and the first transition layer 321. The silicon-nitrogen ratio of the passivation layer 31 is 1:12, and the thickness is 20nm; the silicon-nitrogen ratio of the first transition layer 321 is 1:4, and the thickness is 20nm; the silicon-nitrogen ratio of the second transition layer 322 is 1:7, and the thickness is 20nm; the silicon-nitrogen ratio of the first light-transmitting layer 331 is 1:10, and the thickness is 20nm; the silicon-nitrogen ratio of the second light-transmitting layer 332 is 1:13, and the thickness is 20nm.

[0180] Example 3

[0181] A solar cell 100 is provided, which includes a first doped layer 10, a second doped layer 20 and an anti-reflection film 30. The first doped layer 10 and the second doped layer 20 are stacked and bonded. Two anti-reflection films 30 are provided, and are respectively arranged on a side of the first doped layer 10 away from the second doped layer 20 and a side of the second doped layer 20 away from the first doped layer 10. The first doped layer 10 is an N-type substrate.

[0182] The anti-reflection film 30 includes a stacked and bonded passivation layer 31, a first transition layer 321, a second transition layer 322, a first light-transmitting layer 331, and a second light-transmitting layer 332, and the passivation layer 31 is located between the first doping layer 10 and the first transition layer 321. The silicon-nitrogen ratio of the passivation layer 31 is 1:13, and the thickness is 25nm; the silicon-nitrogen ratio of the first transition layer 321 is 1:4, and the thickness is 30nm; the silicon-nitrogen ratio of the second transition layer 322 is 1:8, and the thickness is 15nm; the silicon-nitrogen ratio of the first light-transmitting layer 331 is 1:11, and the thickness is 30nm; the silicon-nitrogen ratio of the second light-transmitting layer 332 is 1:13, and the thickness is 25nm.

[0183] Comparative Example 1

[0184] A solar cell 100' is provided, comprising a stacked first doped layer 10', a second doped layer 20' and an anti-reflection film 40', wherein the first doped layer 10' is located between the second doped layer 20' and the anti-reflection film 40'. The first doped layer 10' is an N-type substrate.

[0185] The anti-reflection film 40' comprises a passivation layer 41' and a light-transmitting layer 42' which are stacked and bonded, and the passivation layer 41' is located between the first doped layer 10' and the light-transmitting layer 42'. The silicon-nitrogen ratio of the passivation layer 41' is 1:12, and the thickness is 35nm; the silicon-nitrogen ratio of the light-transmitting layer 42' is 1:9, and the thickness is 45nm.

[0186] Comparative Example 2

[0187] A solar cell 100' is provided, comprising a stacked first doped layer 10', a second doped layer 20' and an anti-reflection film 40', wherein the first doped layer 10' is located between the second doped layer 20' and the anti-reflection film 40'. The first doped layer 10' is an N-type substrate.

[0188] The anti-reflection film 40' comprises a passivation layer 41', a transition layer 42' and a light-transmitting layer 43' which are stacked and bonded, and the passivation layer 41' is located between the first doped layer 10' and the transition layer 42'. The silicon-nitrogen ratio of the passivation layer 41' is 1:5, and the thickness is 10nm; the silicon-nitrogen ratio of the transition layer 42' is 1:7, and the thickness is 30nm; the silicon-nitrogen ratio of the light-transmitting layer 43' is 1:10, and the thickness is 40nm.

[0189] The filling factors and photoelectric conversion efficiencies of the solar cells of Example 1, Example 2, Example 3 and Comparative Example 1 and Comparative Example 2 were tested and statistically analyzed, and the results are shown in Table 1 below.

[0190] Table 1:

[0191]

[0192] From the test data obtained above, it can be concluded that the filling factors in Example 1, Example 2 and Example 3 are all greater than the filling factors in Comparative Example 1 and Comparative Example 2. This is because Example 1, Example 2 and Example 3 all adopt the silicon-nitrogen ratio range of the passivation layer 31, the transition layer 32 and the light-transmitting layer 33 provided in the present application, which not only improves the intensity of the light incident on the first doping layer 10, but also passivates the dangling bonds on the surface of the first doping layer 10. As a result, the filling factors in Example 1, Example 2 and Example 3 are greater than the filling factors in Comparative Example 1 and Comparative Example 2.

[0193] At the same time, it can be concluded from the experimental data obtained above that the photoelectric conversion efficiency in Example 1, Example 2 and Example 3 is greater than the photoelectric conversion efficiency of Comparative Example 1 and Comparative Example 2. This is because Example 1, Example 2 and Example 3 all adopt the silicon-nitrogen ratio range of the passivation layer 31, the transition layer 32 and the light-transmitting layer 33 provided in this application, while increasing the intensity of the light incident on the first doping layer 10, it also passivates the dangling bonds on the surface of the first doping layer 10. As a result, the photoelectric conversion efficiency of Example 1, Example 2 and Example 3 is greater than the photoelectric conversion efficiency of Comparative Example 1 and Comparative Example 2.

[0194] To sum up, compared with the prior art, the solar cell 100 of the present application is provided with a transition layer 32 whose silicon-nitrogen ratio is between that of the passivation layer 31 and the light-transmitting layer 33, so that when the passivation layer 31 passivates the dangling bonds on the surface of the first doped layer 10, the transition layer 32 can enhance the passivation effect of the passivation layer 31 on the surface of the first doped layer 10, thereby enhancing the photoelectric conversion efficiency of the solar cell 100 of the present application.

[0195] It should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0196] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0197] It should be understood that the application of the present application is not limited to the above examples. For ordinary technicians in the field, improvements or changes can be made according to the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application. Ordinary technicians in the field can understand that all or part of the processes of the above embodiments are implemented, and equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims

1. A solar cell, characterized in that: It comprises a stacked first doping layer, a second doping layer and an anti-reflection film, wherein the first doping layer is located between the second doping layer and the anti-reflection film; The anti-reflection film includes a passivation layer, a transition layer and a light-transmitting layer which are stacked and bonded together, the passivation layer is close to the first doped layer, and the transition layer is located between the passivation layer and the light-transmitting layer, wherein the silicon-nitrogen ratio of the passivation layer ranges from 1:12 to 1:13, the silicon-nitrogen ratio of the transition layer ranges from 1:7 to 1:8, and the silicon-nitrogen ratio of the light-transmitting layer ranges from 1:10 to 1:

13.

2. The solar cell according to claim 1, characterized in that: The thickness of the passivation layer is between 5nm and 30nm.

3. The solar cell according to claim 1, characterized in that The material of the passivation layer is silicon oxynitride.

4. The solar cell according to claim 1, characterized in that The transition layer includes a stacked first transition layer and a second transition layer, the first transition layer is located between the second transition layer and the passivation layer, the silicon-nitrogen ratio of the first transition layer is in the range of 1:3-1:4, and the silicon-nitrogen ratio of the second transition layer is in the range of 1:6-1:

9.

5. The solar cell according to claim 4, characterized in that: The thickness of the first transition layer is between 20nm and 40nm, and the thickness of the second transition layer is between 5nm and 30nm.

6. The solar cell according to claim 4, characterized in that: The material of the first transition layer is silicon nitride, and the material of the second transition layer is silicon nitride.

7. The solar cell according to claim 1, characterized in that The light-transmitting layer includes a first light-transmitting layer and a second light-transmitting layer stacked together, the first light-transmitting layer is located between the second light-transmitting layer and the transition layer, the silicon-nitrogen ratio of the first light-transmitting layer ranges from 1:10 to 1:11, and the silicon-nitrogen ratio of the second light-transmitting layer ranges from 1:12 to 1:

13.

8. The solar cell according to claim 7, characterized in that: The thickness of the first light-transmitting layer is between 20 nm and 40 nm, and the thickness of the second light-transmitting layer is between 20 nm and 40 nm.

9. The solar cell according to claim 7, characterized in that: The material of the first light-transmitting layer is silicon oxynitride, and the material of the second light-transmitting layer is silicon oxide.

10. The solar cell according to any one of claims 1 to 9, characterized in that: The anti-reflection film further includes a charged film, and the charged film is located between the passivation layer and the first doping layer.

11. The solar cell according to any one of claims 1 to 9, characterized in that: The thickness of the anti-reflection film is between 70nm and 100nm.

12. A method for manufacturing a solar cell, characterized in that: The steps include: manufacturing a stacked first doped layer and a second doped layer; A passivation layer, a transition layer and a light-transmitting layer are successively formed on the surface of the first doped layer away from the second doped layer; wherein the silicon-nitrogen ratio of the passivation layer is in the range of 1:12-1:13, the silicon-nitrogen ratio of the transition layer is in the range of 1:7-1:8, and the silicon-nitrogen ratio of the light-transmitting layer is in the range of 1:10-1:

13.

13. The method for manufacturing a solar cell according to claim 12, characterized in that: The passivation layer, the transition layer and the light-transmitting layer are all made by plasma enhanced chemical vapor deposition.

14. The method for manufacturing a solar cell according to claim 13, characterized in that: When the passivation layer is formed on a surface of the first doped layer away from the second doped layer, the method includes: The passivation layer made of silicon oxynitride is produced by using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:

13.

15. The method for manufacturing a solar cell according to claim 13, characterized in that: When the transition layer is formed on a surface of the first doped layer away from the second doped layer, the method includes: A first transition layer made of silicon nitride is produced on a surface of the passivation layer away from the first doping layer using a gas flow ratio of silane to ammonia between 1:3 and 1:4; A second transition layer made of silicon nitride is produced on a surface of the first transition layer away from the passivation layer by using a gas flow ratio of silane to ammonia between 1:6 and 1:

9.

16. The method for manufacturing a solar cell according to claim 13, characterized in that: When the light-transmitting layer is formed on a surface of the first doping layer away from the second doping layer, the method includes: A first light-transmitting layer made of silicon oxynitride is produced on the surface of the transition layer away from the passivation layer using a gas flow ratio of silane: ammonia: nitrous oxide between 1:1.5:10 and 1:1.5:11; A second light-transmitting layer made of silicon oxide is manufactured on the surface of the first light-transmitting layer away from the transition layer by using a gas flow ratio of silane to nitrous oxide between 1:12 and 1:13.

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