Solar cell and photovoltaic module

Abstract

The application relates to the photovoltaic technology field and discloses a solar cell and a photovoltaic module. The solar cell disclosed by the application comprises a substrate, a first oxide layer, a second oxide layer, a first doped layer, a second doped layer, a passivation layer and an electrode. The first oxide layer covers the first surface of the substrate. The first doped layer covers the surface of the first oxide layer away from the substrate. The second oxide layer covers the surface of the first doped layer away from the first oxide layer. The second doped layer covers the surface of the second oxide layer away from the first doped layer. The passivation layer covers the surface of the second doped layer away from the second oxide layer. The electrode penetrates the passivation layer, the second doped layer and the second oxide layer in sequence to be connected with the first doped layer and the second doped layer, so that the conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Technology

[0002] Currently, in the production process of solar cells (such as topcon cells and back contact cells), the P-region and N-region are mainly prepared by depositing a silicon oxide tunneling layer and a poly Si layer by LPCVD, and then performing boron diffusion and phosphorus diffusion respectively to form boron-doped p-poly Si and phosphorus-doped n-poly Si structures. Subsequently, silver conductive paste printed by screen printing comes into contact with p-poly Si and n-poly Si respectively to form conductive paths.

[0003] However, the conversion efficiency of current solar cells is still relatively low. Utility Model Content

[0004] The purpose of this application is to provide a solar cell and a photovoltaic module, thereby improving the conversion efficiency of the solar cell.

[0005] To address the aforementioned technical problems, embodiments of this application provide a solar cell, comprising: a substrate, a first oxide layer, a second oxide layer, a first doped layer, a second doped layer, a passivation layer, and an electrode; the first oxide layer covers a first surface of the substrate; the first doped layer covers the surface of the first oxide layer away from the substrate; the second oxide layer covers the surface of the first doped layer away from the first oxide layer; the second doped layer covers the surface of the second oxide layer away from the first doped layer; the passivation layer covers the surface of the second doped layer away from the second oxide layer; the electrode sequentially penetrates the passivation layer, the second doped layer, and the second oxide layer to connect with the first doped layer and the second doped layer.

[0006] Embodiments of this application also provide a photovoltaic module, including: a solar cell as described above.

[0007] In some embodiments, the first oxide layer includes at least a first barrier layer and a second barrier layer; the first barrier layer covers a first surface of the substrate, and the second barrier layer covers the surface of the first barrier layer away from the substrate; the first barrier layer and the second barrier layer are made of different materials.

[0008] In some embodiments, the second oxide layer includes at least a third barrier layer and a fourth barrier layer; the third barrier layer covers the first doped layer, and the fourth barrier layer covers the surface of the third barrier layer away from the first doped layer; the third barrier layer and the fourth barrier layer are made of different materials.

[0009] In some embodiments, the passivation layer includes at least an aluminum oxide layer and a silicon nitride layer, wherein the aluminum oxide layer covers the second doped layer, and the silicon nitride layer covers the surface of the aluminum oxide layer away from the second doped layer; the thickness of the aluminum oxide layer is less than the thickness of the silicon nitride layer.

[0010] In some embodiments, the doping concentration of the first doped layer is lower than that of the second doped layer.

[0011] In some embodiments, the thickness of the first oxide layer is greater than the thickness of the second oxide layer.

[0012] In some embodiments, the thickness of the first doped layer is greater than the thickness of the second doped layer.

[0013] In some embodiments, the dopant ions of the first doped layer and the dopant ions of the second doped layer are both boron ions; or, the dopant ions of the first doped layer and the dopant ions of the second doped layer are both phosphorus ions.

[0014] In some embodiments, the second oxide layer and the second doped layer form an oxide-doped structure; the solar cell includes a plurality of the oxide-doped structures.

[0015] The technical solution provided in this application has at least the following advantages: In the solar cell of this application embodiment, by setting a first oxide layer, a second oxide layer, a first doped layer, and a second doped layer, during the doping process of the second doped layer, even if the dopant concentration of the second doped layer is high, some dopant ions may pass through the second oxide layer to reach the first doped layer. However, due to the setting of the second oxide layer, the concentration of dopant ions reaching the first doped layer is less than that of the second doped layer, which reduces the probability of dopant ions penetrating the first oxide layer to reach the substrate. Under the premise of ensuring good substrate performance, the doping concentration of the second doped layer is increased as much as possible, so that the electrode forms a good ohmic contact with the first and second doped layers, reducing the contact resistivity of the solar cell and improving the conversion efficiency of the solar cell. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of the structure of a solar cell according to an embodiment of this application; Figure 2 This is another structural schematic diagram of a solar cell according to an embodiment of this application; Figure 3 This is another structural schematic diagram of a solar cell according to an embodiment of this application; Figure 4 This is a schematic diagram of another structure of a solar cell according to an embodiment of this application; Figure 5 This is another structural schematic diagram of a solar cell according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures Substrate (10), first oxide layer (20), first barrier layer (21), second barrier layer (22), second oxide layer (30), third barrier layer (31), fourth barrier layer (32), first doped layer (40), second doped layer (50), passivation layer (60), electrode (70), aluminum oxide layer (601), silicon nitride layer (602), oxide doped structure (35). Detailed Implementation

[0019] As can be seen from the background technology, existing solar cells still have the technical problem of low conversion efficiency.

[0020] Analysis revealed that the low conversion efficiency of existing solar cells stems from several factors. While the boron or phosphorus doping concentration in the polySi layer remains relatively constant during fabrication, the presence of a SiO2 tunneling layer between the polySi layer and the substrate hinders the further diffusion of boron or phosphorus dopants into the substrate. Consequently, the concentration of boron or phosphorus dopants in the substrate decreases sharply, resulting in a gradually decreasing doping profile. However, despite this, at higher doping concentrations, a significant number of boron or phosphorus dopants can still penetrate the substrate, increasing the risk of diffusion penetration. Therefore, a higher doping concentration of boron or phosphorus dopants is desirable for achieving good ohmic contact, reducing contact resistivity, and improving cell conversion efficiency. In other words, in the current solar cell fabrication process, if the doping concentration is too low, it cannot form a good ohmic contact with the metal electrode, which will increase the contact resistivity and affect the cell conversion efficiency. If the doping concentration is too high, the SiO2 tunneling layer will have difficulty blocking the diffusion of boron or phosphorus ions into the silicon substrate, which will easily lead to the risk of diffusion penetration, resulting in severe diffusion into the substrate. This will cause the cell's dark saturation current density (J0) to increase sharply and the open circuit voltage (Voc) to decrease sharply. At the same time, high concentrations of doping in polySi will also lead to an increase in free carrier absorption (FCA), a decrease in short-circuit current density (Jsc), and a decrease in cell conversion efficiency.

[0021] To address the aforementioned technical problems, this application provides a solar cell comprising: a substrate, a first oxide layer, a second oxide layer, a first doped layer, a second doped layer, a passivation layer, and an electrode; the first oxide layer covers a first surface of the substrate; the first doped layer covers the surface of the first oxide layer away from the substrate; the second oxide layer covers the surface of the first doped layer away from the first oxide layer; the second doped layer covers the surface of the second oxide layer away from the first doped layer; the passivation layer covers the surface of the second doped layer away from the second oxide layer; and the electrode sequentially penetrates the passivation layer, the second doped layer, and the second oxide layer to be connected to the first doped layer and the second doped layer.

[0022] In the solar cell of this application embodiment, by setting a first oxide layer, a second oxide layer, a first doped layer, and a second doped layer, during the doping process of the second doped layer, even if the dopant concentration of the second doped layer is high, some dopant ions may pass through the second oxide layer to reach the first doped layer. However, due to the setting of the second oxide layer, the concentration of dopant ions reaching the first doped layer is less than that of the second doped layer, which reduces the probability of dopant ions penetrating the first oxide layer to reach the substrate. Under the premise of ensuring good substrate performance, the doping concentration of the second doped layer is increased as much as possible, so that the electrode forms a good ohmic contact with the first and second doped layers, reducing the contact resistivity of the solar cell and improving the conversion efficiency of the solar cell.

[0023] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. Furthermore, when describing a component as "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0029] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. The formation or provision of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be present between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or provision of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" may refer to a layer, film, region, portion, structure, etc.

[0030] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0031] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0032] One embodiment of this application relates to a solar cell, and a schematic diagram of the structure of the solar cell in this embodiment is shown below. Figure 1 As shown, the solar cell includes: a substrate 10, a first oxide layer 20, a second oxide layer 30, a first doped layer 40, a second doped layer 50, a passivation layer 60, and an electrode 70.

[0033] refer to Figure 1 A first oxide layer 20 covers the first surface of the substrate 10; a first doped layer 40 covers the surface of the first oxide layer 20 away from the substrate 10; a second oxide layer 30 covers the surface of the first doped layer 40 away from the first oxide layer 20; a second doped layer 50 covers the surface of the second oxide layer 30 away from the first doped layer 40; a passivation layer 60 covers the surface of the second doped layer 50 away from the second oxide layer 30; an electrode 70 sequentially penetrates the passivation layer 60, the second doped layer 50, and the second oxide layer 30 to connect with the first doped layer 40 and the second doped layer 50. The first oxide layer 20 and the second oxide layer 30 are both silicon dioxide.

[0034] In this embodiment, the solar cell is provided with a first oxide layer 20, a second oxide layer 30, a first doped layer 40, and a second doped layer 50. During the doping process of the second doped layer 50, even when the dopant concentration of the second doped layer 50 is high, some dopant ions may pass through the second oxide layer 30 to reach the first doped layer 40. However, due to the provision of the second oxide layer 30, the concentration of dopant ions reaching the first doped layer 40 is less than that of the second doped layer 50, reducing the probability of dopant ions penetrating the first oxide layer 20 to reach the substrate 10. While ensuring the good performance of the substrate 10, the doping concentration of the second doped layer 50 is increased as much as possible, so that the electrode 70 forms a good ohmic contact with the first doped layer 40 and the second doped layer 50, reducing the contact resistivity of the solar cell and improving the conversion efficiency of the solar cell.

[0035] like Figure 2 As shown, this is another structural schematic diagram of the solar cell in this embodiment. The first oxide layer 20 in this embodiment includes at least a first barrier layer 21 and a second barrier layer 22. The first barrier layer 21 covers the first surface of the substrate 10, and the second barrier layer 22 covers the surface of the first barrier layer 21 away from the substrate 10.

[0036] The first barrier layer 21 and the second barrier layer 22 are made of different materials. The first barrier layer 21 and the second barrier layer 22 can be any of the following materials: aluminum oxide, zirconium oxide, silicon nitride, and silicon oxynitride.

[0037] In this embodiment, by setting the first oxide layer 20 as a two-layer structure of a first barrier layer 21 and a second barrier layer 22, the blocking effect of the first oxide layer 20 can be improved, further reducing the probability of doped ions penetrating the substrate 10, thereby increasing the doped ion concentration of the first doped layer 40 and improving the conversion efficiency of the solar cell.

[0038] refer to Figure 2 The second oxide layer 30 includes at least a third barrier layer 31 and a fourth barrier layer 32; the third barrier layer 31 covers the first doped layer 40, and the fourth barrier layer 32 covers the surface of the third barrier layer 31 away from the first doped layer 40.

[0039] The third barrier layer 31 and the fourth barrier layer 32 are made of different materials. The third barrier layer 31 and the fourth barrier layer 32 can be any of the following materials: aluminum oxide, zirconium oxide, silicon nitride, and silicon oxynitride.

[0040] In this embodiment, by setting the second oxide layer 30 as a two-layer structure of the third barrier layer 31 and the fourth barrier layer 32, the barrier effect of the second oxide layer 30 can be improved. With the dopant ion concentration of the second doped layer 50 remaining unchanged, the number of dopant ions entering the first doped layer 40 can be further reduced. Therefore, with the dopant ion concentration of the first doped layer 40 remaining unchanged, the dopant ion concentration of the second doped layer 50 can be increased, thereby further improving the conversion efficiency of the solar cell.

[0041] Because the first doped layer 40 is close to the first oxide layer 20, during the doping process of the first doped layer 40, in order to avoid the risk of dopant ions diffusing to the substrate 10 and causing the substrate 10 to experience a breakthrough, resulting in a sharp increase in J0 and a sharp decrease in Voc of the battery, the doping concentration of the first doped layer 40 is relatively low. This ensures that the first doped layer 40 is doped while maintaining good performance of the substrate 10. However, during the doping process of the second doped layer 50, when the dopant ion concentration of the second doped layer 50 is high, some dopant ions will penetrate the second oxide layer 30 to reach the first doped layer 40. Due to the presence of the second oxide layer 30, the concentration of dopant ions reaching the first doped layer 40 is less than that of the second doped layer 50, reducing the probability of dopant ions penetrating the first oxide layer 20 to reach the substrate 10. Therefore, the doping concentration of the second doped layer 50 can be set higher.

[0042] Therefore, in this embodiment, the doping concentration of the first doped layer 40 is lower than that of the second doped layer 50, thereby further ensuring that the substrate 10 does not have the risk of penetration. At the same time, the doping concentration of the second doped layer 50 is further increased, so that the electrode 70 forms a good ohmic contact with the first doped layer 40 and the second doped layer 50, reducing the contact resistivity of the solar cell and improving the conversion efficiency of the solar cell.

[0043] In this embodiment, both the first doped layer 40 and the second doped layer 50 are boron ions; or, both the first doped layer 40 and the second doped layer 50 are phosphorus ions. When both the first doped layer 40 and the second doped layer 50 are boron ions, the boron doping concentration of the first doped layer 40 is (E18-E19) / cm³. 3 The boron doping concentration of the second doped layer 50 is (E19-E20) / cm. 3 When both the dopant ions in the first doped layer 40 and the dopant ions in the second doped layer 50 are phosphorus ions, the phosphorus doping concentration in the first doped layer 40 is (E19-E20) / cm³. 3 The phosphorus doping concentration of the second doped layer 50 is (E20-E21) / cm. 3 .

[0044] In this embodiment, the thickness of the first oxide layer 20 is greater than the thickness of the second oxide layer 30. Specifically, the thickness of the first oxide layer 20 is 1 nm to 3 nm, for example, 1 nm, 1.2 nm, 1.5 nm, 1.8 nm, 2 nm, 2.2 nm, 2.5 nm, 2.8 nm, or 3 nm, and the thickness of the second oxide layer 30 is 0.2 nm to 2 nm, for example, 0.2 nm, 0.5 nm, 0.8 nm, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm, or 2 nm. Since the first oxide layer 20 can block the diffusion of dopant ions to the substrate 10, its thickness is relatively large. This thickness is more effective in preventing dopant ions from diffusing to the substrate 10 during the doping process of the first doped layer 40 and the second doped layer 50, thus ensuring the performance of the substrate 10. Conversely, the second oxide layer 30 is relatively thin, allowing some dopant ions to diffuse through it to the first doped layer 40 during the doping process of the second doped layer 50. This achieves doping of the first doped layer 40, improves the ohmic contact between the electrode 70 and the first doped layer 40, thereby reducing the contact resistivity of the solar cell and increasing its conversion efficiency. During the diffusion of dopant ions from the second oxide layer 30 to the first doped layer 40, the dopant ion concentration in the second doped layer 50 exhibits a stepwise variation with the concentration in the first doped layer 40. The dopant ion concentration in the second doped layer 50 is greater than that in the first doped layer 40. This ensures that the dopant ion concentration in the second doped layer 50 is maximized while avoiding the risk of diffusion-through in the substrate 10, thus improving the performance of the substrate 10.

[0045] In this embodiment, the thickness of the first doped layer 40 is greater than the thickness of the second doped layer 50. Specifically, the thickness of the first doped layer 40 is 40 nm to 280 nm, such as 40 nm, 100 nm, 150 nm, 200 nm, 250 nm, and 280 nm, while the thickness of the second doped layer 50 is 20 nm to 140 nm, such as 20 nm, 50 nm, 80 nm, 100 nm, 120 nm, and 140 nm. Since the doping process of the first doped layer 40 needs to prevent dopant ions from diffusing into the substrate 10, setting the thickness of the first doped layer 40 to be thicker reduces the probability of dopant ions diffusing into the substrate 10, avoids the risk of substrate 10 perforation, and improves the performance of the substrate 10. Meanwhile, during the doping process of the second doped layer 50, since the second doped layer 50 is relatively thin, some doped ions will diffuse to the first doped layer 40, thereby doping the first doped layer 40. This allows the electrode 70 to form a good ohmic contact with the first doped layer 40 and the second doped layer 50, reducing the contact resistivity of the solar cell and improving the conversion efficiency of the solar cell.

[0046] In this embodiment, the passivation layer 60 includes at least an aluminum oxide layer 601 and a silicon nitride layer 602. The aluminum oxide layer 601 covers the second doped layer 50, and the silicon nitride layer 602 covers the surface of the aluminum oxide layer 601 away from the second doped layer 50. The aluminum oxide layer 601 is a dense thin film that reduces dangling bonds and defects on the surface of the silicon substrate 10, thereby reducing the recombination rate of minority carriers on the surface. The silicon nitride layer 602 has good optical transparency and anti-reflection properties, which can effectively reduce reflection losses on the surface of the solar cell, improve light absorption efficiency, and thus improve the conversion efficiency of the solar cell.

[0047] Specifically, the thickness of the alumina layer 601 is less than the thickness of the silicon nitride layer 602. The thickness of the alumina layer 601 is 3 nm to 10 nm, for example, 3 nm, 5 nm, 8 nm, 10 nm, while the thickness of the silicon nitride layer 602 is 60 nm to 100 nm, for example, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm. The refractive index of the silicon nitride layer 602 is 2.05 to 2.25, for example, 2.05, 2.1, 2.15, 2.2, 2.25.

[0048] In this embodiment, the second oxide layer 30 and the second doped layer 50 form an oxide-doped structure 35. The solar cell in this embodiment includes multiple oxide-doped structures, such as... Figure 3 The diagram shown is another structural schematic of the solar cell in this embodiment. Figure 3 The example uses three oxide-doped structures. In practical applications, there can be two, four, five, or other oxide-doped structures, depending on the actual needs. This embodiment does not impose any specific limitations.

[0049] refer to Figure 3 In this embodiment, each oxide-doped structure 35 includes a second oxide layer 30 and a second doped layer 50. Multiple oxide-doped structures 35 are sequentially disposed on the surface of the first doped layer 40 away from the first oxide layer 20. Figure 3 The structure includes three oxide-doped structures 35, which are, from the inside out, the first oxide-doped structure 35, the second oxide-doped structure 35, and the third oxide-doped structure 35. That is, on the surface of the first doped layer 40 away from the first oxide layer 20, the second oxide layer 30 and the second doped layer 50 of the first oxide-doped structure 35 are first set in sequence, then the second oxide layer 30 and the second doped layer 50 of the second oxide-doped structure 35 are set in sequence, and finally the second oxide layer 30 and the second doped layer 50 of the third oxide-doped structure 35 are set in sequence, and so on in a cyclic manner.

[0050] Specifically, the dopant ion concentrations in the second doped layer 50 of the multilayer oxide doped structure 35 are different. The closer the second doped layer 50 is to the substrate 10, the lower the dopant ion concentration, and the farther the second doped layer 50 is from the substrate 10, the higher the dopant ion concentration.

[0051] refer to Figure 3 The dopant concentration of the second doped layer 50 in the first oxide doped structure 35 is lower than that in the second doped layer 50 of the third oxide doped structure 35. Since each oxide doped structure 35 contains a second oxide layer 30, when the second doped layer 50 in the oxide doped structure 35 is doped, the dopant concentration of the second doped layer 50 in the third oxide doped structure 35 is higher. After being blocked by the second oxide layer 30 in the third oxide doped structure 35, the dopant concentration of the second doped layer 50 reaching the second oxide doped structure 35 decreases. After further blocking by the second oxide layer 30 in the second oxide doped structure 35, the dopant concentration of the second doped layer 50 reaching the first oxide doped structure 35 further decreases, thus resulting in a stepwise change in the dopant concentration of the second doped layer 50 in the multi-layered oxide doped structure 35.

[0052] The solar cell in this embodiment can be a back-contact cell, such as... Figure 4 As shown, this is another structural schematic diagram of the solar cell in this embodiment. The P-region and N-region of the back contact cell are respectively configured as follows: Figure 1 The hierarchical structure shown can also be configured such that the P and N regions of the back contact battery are set as follows: Figure 3 The hierarchical structure shown has both the P-region and N-region of the back-contact battery located on the back side of the battery. The P-region is used to collect holes, and the N-region is used to collect electrons. The back side of the battery also has a GAP region between the P-region and the N-region, on which a passivation layer is also formed. Specifically, the doping ions of the P-region and the N-region are different. The doping ions of the first doped layer 40 and the second doped layer 50 of the P-region are both boron ions, while the doping ions of the first doped layer 40 and the second doped layer 50 of the N-region are both phosphorus ions. When light shines on the back side of the back-contact battery, photogenerated carriers (electrons and holes) separate under the influence of the built-in electric field of the PN junction. Electrons move towards the N-region, and holes move towards the P-region, thereby generating current.

[0053] The solar cell in this embodiment can be a Topcon cell, such as... Figure 5As shown, this is another structural schematic diagram of the solar cell in this embodiment. The P-region and N-region of the Topcon cell are respectively arranged as follows: Figure 1 As shown in the hierarchical structure, the P and N regions of the Topcon battery can also be configured as follows: Figure 3 As shown in the hierarchical structure, the P-region and N-region of the Topcon battery are located on the front and back sides of the battery, respectively. The P-region is used to collect holes, and the N-region is used to collect electrons. Specifically, the doping ions of the P-region and the N-region are different. The doping ions of the first doped layer 40 and the second doped layer 50 of the P-region are both boron ions, while the doping ions of the first doped layer 40 and the second doped layer 50 of the N-region are both phosphorus ions. When light shines on the back side of the battery, photogenerated carriers (electrons and holes) separate under the influence of the built-in electric field of the PN junction. Electrons move towards the N-region, and holes move towards the P-region, thereby generating current.

[0054] An embodiment of this application also relates to a photovoltaic module, including the solar cell described in the above embodiment.

[0055] The photovoltaic module of this embodiment includes the solar cell of the above embodiment. Since the solar cell has good ohmic contact, low contact resistivity, and high conversion efficiency, the photovoltaic module of this embodiment has high photoelectric conversion efficiency by setting the solar cell.

[0056] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A solar cell, characterized in that, include: Substrate, first oxide layer, second oxide layer, first doped layer, second doped layer, passivation layer, electrode; The first oxide layer covers the first surface of the substrate; The first doped layer covers the surface of the first oxide layer away from the substrate; The second oxide layer covers the surface of the first doped layer away from the first oxide layer; the second doped layer covers the surface of the second oxide layer away from the first doped layer; the passivation layer covers the surface of the second doped layer away from the second oxide layer; The electrode passes through the passivation layer, the second doped layer, and the second oxide layer in sequence to connect with the first doped layer and the second doped layer.

2. The solar cell according to claim 1, characterized in that, The first oxide layer includes at least a first barrier layer and a second barrier layer; The first barrier layer covers a first surface of the substrate, and the second barrier layer covers the surface of the first barrier layer away from the substrate; the first barrier layer and the second barrier layer are made of different materials.

3. The solar cell according to claim 1, characterized in that, The second oxide layer includes at least a third barrier layer and a fourth barrier layer; The third barrier layer covers the first doped layer, and the fourth barrier layer covers the surface of the third barrier layer away from the first doped layer; the third barrier layer and the fourth barrier layer are made of different materials.

4. The solar cell according to any one of claims 1 to 3, characterized in that, The passivation layer includes at least an aluminum oxide layer and a silicon nitride layer, wherein the aluminum oxide layer covers the second doped layer, and the silicon nitride layer covers the surface of the aluminum oxide layer away from the second doped layer; the thickness of the aluminum oxide layer is less than the thickness of the silicon nitride layer.

5. The solar cell according to claim 1, characterized in that, The doping concentration of the first doped layer is lower than that of the second doped layer.

6. The solar cell according to claim 1, characterized in that, The thickness of the first oxide layer is greater than the thickness of the second oxide layer.

7. The solar cell according to claim 1, characterized in that, The thickness of the first doped layer is greater than the thickness of the second doped layer.

8. The solar cell according to claim 1, characterized in that, The doping ions of the first doped layer and the doping ions of the second doped layer are both boron ions; or, the doping ions of the first doped layer and the doping ions of the second doped layer are both phosphorus ions.

9. The solar cell according to any one of claims 1 to 3, characterized in that, The second oxide layer and the second doped layer form an oxide-doped structure; the solar cell includes a plurality of the oxide-doped structures.

10. A photovoltaic module, characterized in that, include: The solar cell as described in any one of claims 1 to 9.

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