Back contact solar cell, solar laminated cell and photovoltaic module

Abstract

The invention provides a back contact solar cell, a solar laminated cell and a photovoltaic module, and relates to the field of photovoltaic technology, the back contact solar cell comprises a substrate, a carrier transport layer, a first anti-reflection layer, a first electrode and a second electrode, the substrate comprises a first surface with a first part and a second part, the first part is provided with a first passivation contact structure, the second part is provided with a second passivation contact structure, the carrier transmission layer is located on the sides, away from the substrate, of the first passivation contact structure and the second passivation contact structure, the first anti-reflection layer is located on the side, away from the substrate, of the carrier transmission layer, and the first electrode is located on the carrier transmission layer. The first electrode is located on the carrier transmission layer and electrically connected with the first passivation contact structure, the second electrode is located on the carrier transmission layer and electrically connected with the second passivation contact structure, the projection of the first electrode is located in the projection of the first passivation contact structure, the projection of the second electrode is located in the projection of the second passivation contact structure, and the cell efficiency is improved through the design.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, specifically to a back-contact solar cell, a solar tandem cell, and a photovoltaic module. Background Technology

[0002] Back-contact solar cells are used to convert solar energy into electrical energy. Currently, back-contact solar cells suffer from problems such as parasitic absorption of light, resulting in poor efficiency. Summary of the Invention

[0003] In view of this, this application provides a back-contact solar cell, a solar tandem cell, and a photovoltaic module to help solve the problem of poor efficiency of back-contact solar cells in the prior art.

[0004] A first aspect of this application provides a back-contact solar cell, including a substrate, a carrier transport layer, a first anti-reflection layer, a first electrode, and a second electrode. The substrate includes a first surface and a second surface disposed opposite to each other along a first direction. The first surface includes a first portion and a second portion alternately arranged along a second direction. A first passivation contact structure is disposed on the first portion, and a second passivation contact structure is disposed on the second portion. The carrier transport layer is located on the side of the first passivation contact structure and the second passivation contact structure away from the substrate. The first anti-reflection layer is located on the side of the carrier transport layer away from the substrate. The first electrode is located on the carrier transport layer. The projection of the first electrode along the first direction is located within the projection of the first passivation contact structure along the first direction, and the first electrode is electrically connected to the first passivation contact structure. The second electrode is located on the carrier transport layer. The projection of the second electrode along the first direction is located within the projection of the second passivation contact structure along the first direction, and the second electrode is electrically connected to the second passivation contact structure.

[0005] In some possible implementations, the first passivation contact structure includes a tunneling oxide layer and an N-type doped layer arranged in the first direction, the N-type doped layer being located on the side of the tunneling oxide layer away from the substrate, and the first electrode being electrically connected to the N-type doped layer. The second passivation contact structure includes a doped amorphous silicon layer and a P-type doped layer arranged along the first direction, the P-type doped layer being located on the side of the doped amorphous silicon layer away from the substrate, and the second electrode being electrically connected to the P-type doped layer.

[0006] In some possible implementations, the thickness of the carrier transport layer along the first direction is D1, and the thickness of the first antireflection layer along the first direction is D2, where D1 and D2 satisfy: 0.005≤D1 / D2≤0.03.

[0007] In some possible implementations, the thickness D1 of the carrier transport layer along the first direction satisfies: 1nm ≤ D1 ≤ 2nm.

[0008] In some possible implementations, the carrier transport layer includes at least one of silicon oxide, titanium oxide, and nickel oxide.

[0009] In some possible implementations, the first antireflection layer includes a silicon nitride layer with a thickness D3 along the first direction, wherein D3 satisfies: 60nm ≤ D3 ≤ 90nm.

[0010] In some possible implementations, the first antireflection layer includes a silicon nitride layer and a silicon oxynitride layer arranged along the first direction, wherein the silicon oxynitride layer is located on the side of the silicon nitride layer opposite to the substrate, and the thickness of the silicon oxynitride layer is less than the thickness of the silicon nitride layer.

[0011] In some possible implementations, the thickness of the silicon nitride layer along the first direction is D3, where D3 satisfies: 45nm≤D3≤65nm, and the thickness of the silicon oxynitride layer along the first direction is D4, where D4 satisfies: 20nm≤D4≤45nm.

[0012] In some possible implementations, the first antireflection layer includes a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer arranged along the first direction, wherein the silicon nitride layer is located on the side of the silicon oxynitride layer facing the substrate, the silicon oxide layer is located on the side of the silicon oxynitride layer away from the substrate, and the thickness of the silicon oxynitride layer is less than the thickness of the silicon nitride layer, and the thickness of the silicon oxide layer is less than the thickness of the silicon oxynitride layer.

[0013] In some possible implementations, the thickness of the silicon nitride layer along the first direction is D3, where D3 satisfies: 40nm≤D3≤60nm; the thickness of the silicon oxynitride layer along the first direction is D4, where D4 satisfies: 20nm≤D4≤40nm; and the thickness of the silicon oxide layer along the first direction is D5, where D5 satisfies: 10nm≤D4≤20nm.

[0014] In some possible implementations, the first passivation contact structure includes a first sub-part and a second sub-part arranged along the second direction, and the second passivation contact structure includes a third sub-part and a fourth sub-part arranged along the second direction. The third sub-part is stacked along the first direction on the side of the first sub-part facing away from the substrate. The projection of the first electrode along the first direction is located within the projection of the second sub-part along the first direction, and the projection of the second electrode along the first direction is located within the projection of the fourth sub-part along the first direction.

[0015] In some possible implementations, the distance from the first portion to the second surface along the first direction is greater than the distance from the second portion to the second surface along the first direction.

[0016] In some possible implementations, the first portion and / or the second portion have a pyramid-shaped microstructure.

[0017] In some possible implementations, the back-contact solar cell further includes a passivation layer and a second antireflection layer, the passivation layer being disposed on the second surface and the second antireflection layer being disposed along the first direction on the side of the passivation layer opposite to the substrate.

[0018] In some possible implementations, the passivation layer includes at least one of aluminum oxide, silicon oxide, and hydrogenated amorphous silicon, and the second antireflection layer includes at least one of silicon nitride, silicon oxynitride, and silicon oxide.

[0019] A second aspect of this application provides a solar tandem cell, including a crystalline silicon bottom cell and a perovskite top cell, wherein the crystalline silicon bottom cell includes a back-contact solar cell as described above, and the perovskite top cell is electrically connected to the crystalline silicon bottom cell.

[0020] A third aspect of this application provides a photovoltaic module, the photovoltaic module including a cover plate, an encapsulation layer and a battery string, the battery string including a plurality of back-contact solar cells as described above, or the battery string including a plurality of solar tandem cells as described above.

[0021] The beneficial effects of this application are as follows: In the embodiments of this application, the first antireflection layer has weak parasitic absorption, resulting in less light absorption loss, and exhibits excellent passivation effect. The carrier transport layer provides a certain degree of barrier effect against metal elements in the first and second electrodes, reducing the risk of substrate structure damage caused by the diffusion of metal elements from the first and second electrodes towards the substrate, while ensuring the passivation effect of the first and second passivation contact structures. By providing the carrier transport layer and the first antireflection layer, the back-contact solar cell no longer needs to have a transparent conductive layer, thereby improving the photoelectric conversion efficiency of the back-contact solar cell, simplifying the fabrication process of the back-contact solar cell, and reducing the production cost of the back-contact solar cell.

[0022] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a back-contact solar cell provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the first antireflection layer of a back-contact solar cell in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of a back-contact solar cell provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a back-contact solar cell provided in another embodiment of this application; Figure 5 This is a schematic diagram of the substrate of a back-contact solar cell in one embodiment of this application; Figure 6 This is a schematic diagram of the structure of a back-contact solar cell provided in another embodiment of this application; Figure 7 This is a schematic diagram of the substrate of the back-contact solar cell in another embodiment of this application; Figure 8 This is a schematic diagram of a back-contact solar cell structure with an insulating structure in one embodiment of this application; Figure 9 This is a schematic diagram of the structure of a solar tandem battery provided in one embodiment of this application; Figure 10 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0025] Figure label: 10-Back contact solar cell; 11-Substrate; 111-First surface; 1111-First portion; 1112-Second portion; 1113-Third portion; 112-Second surface; 12-First passivation contact structure; 121-Tunneling oxide layer; 122-N-type doped layer; 12a-First sub-section; 12b-Second sub-section; 13-Second passivation contact structure; 131-Doped amorphous silicon layer; 132-P-type doped layer; 13a-Third sub-section; 13b-Fourth sub-section; 14-Carrier transport layer; 15-First antireflection layer; 151-Silicon nitride layer; 1511-First sub-layer; 1512-Second sub-layer; 1513-Third sub-layer; 152-Silicon oxynitride layer; 153-Silicon oxide layer; 16-First electrode; 17-Second electrode; 181-Passivation layer; 182-Antireflection layer; 19-Insulating structure; 20-Perovskite top cell; 21-First transport layer; 22-Perovskite layer; 23-Second transport layer; 24-Transparent conductive layer; 25-Third electrode; 30-Composite layer; 100 - Photovoltaic module; 101 - First cover plate; 102 - First encapsulation layer; 103 - Battery string; 104 - Second encapsulation layer; 105 - Second cover plate. Detailed Implementation

[0026] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0028] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0030] like Figure 1 As shown, this application provides a back-contact solar cell 10, including a substrate 11, a first passivated contact structure 12, a second passivated contact structure 13, a carrier transport layer 14, a first anti-reflection layer 15, a first electrode 16, and a second electrode 17.

[0031] Substrate 11 can be an N-type substrate or a P-type substrate. The N-type substrate can be a silicon substrate doped with an N-type element, specifically a pentavalent element such as phosphorus, arsenic, or antimony. The P-type substrate can be a silicon substrate doped with a P-type element, specifically a trivalent element such as boron, indium, or gallium.

[0032] The substrate 11 includes a first surface 111 and a second surface 112 disposed opposite to each other along a first direction Z. The first direction Z can be the thickness direction of the back contact solar cell 10. The first surface 111 can be the back side of the substrate 11, that is, the surface of the substrate 11 that is not directly exposed to sunlight. The second surface 112 can be the front side of the substrate 11, that is, the surface of the substrate 11 that can be directly exposed to sunlight. Both the first surface 111 and the second surface 112 can receive sunlight and convert light energy into electrical energy.

[0033] The first surface 111 includes a first portion 1111 and a second portion 1112 arranged alternately along a second direction X, which is perpendicular to the first direction Z. The second direction X can be the length or width direction of the back-contact solar cell 10. A first passivation contact structure 12 is disposed on the first portion 1111, and a second passivation contact structure 13 is disposed on the second portion 1112. The first passivation contact structure 12 and the second passivation contact structure 13 are used to achieve interface passivation and carrier transport. The first passivation contact structure 12 has a first doping element, and the second passivation contact structure 13 has a second doping element. The first doping element and the second doping element have different doping types. In some embodiments, the first doping element is an N-type element, and the second doping element is a P-type element.

[0034] The carrier transport layer 14 is located on the side of the first passivation contact structure 12 and the second passivation contact structure 13 facing away from the substrate 11. The first electrode 16 and the second electrode 17 are located on the carrier transport layer 14. The projection of the first electrode 16 along the first direction Z lies within the projection of the first passivation contact structure 12 along the first direction Z, and the first electrode 16 is electrically connected to the first passivation contact structure 12. The projection of the second electrode 17 along the first direction Z lies within the projection of the second passivation contact structure 13 along the first direction Z, and the second electrode 17 is electrically connected to the second passivation contact structure 13. One of the first electrode 16 and the second electrode 17 is a positive electrode, and the other is a negative electrode.

[0035] The carrier transport layer 14 has a high resistivity and weak conductivity. It acts as a barrier to the metal elements in the first electrode 16 and the second electrode 17. Simultaneously, its thinness allows carriers to pass through via quantum tunneling. In some embodiments, the carrier transport layer 14 can be a weakly conductive metal oxide; in other embodiments, it can be a weakly conductive non-metal oxide.

[0036] The first electrode 16 and the second electrode 17 can be made of metal paste, which may include at least one of silver, aluminum, copper, tin, gold, lead, or nickel. During the sintering process of the metal paste, metal elements in the metal paste diffuse toward the substrate 11, thereby damaging the substrate 11 and affecting the passivation effect of the first passivation contact structure 12 and the second passivation contact structure 13, thus affecting the efficiency of the back contact solar cell 10. In this embodiment, the first electrode 16 and the second electrode 17 are disposed on the carrier transport layer 14. The carrier transport layer 14 provides a certain degree of obstruction to the metal elements in the first electrode 16 and the second electrode 17, thereby reducing the risk of the diffusion of metal elements in the first electrode 16 and the second electrode 17 toward the substrate 11 and causing damage to the structure of the substrate 11, while ensuring the passivation effect of the first passivation contact structure 12 and the second passivation contact structure 13, and improving the efficiency of the back contact solar cell 10.

[0037] The first antireflection layer 15 is located on the side of the carrier transport layer 14 facing away from the substrate 11. The function of the first antireflection layer 15 is to reduce light reflection, thereby increasing the light transmittance of the back-contact solar cell 10 surface, thus enhancing the carrier concentration on the back-contact solar cell 10 and improving its efficiency. The first antireflection layer 15 can be a non-metallic layer, meaning it does not contain any metal elements. For example, the first antireflection layer 15 can be a silicon nitride layer. The first antireflection layer 15 has a high resistivity and weak conductivity, and can be considered an insulator or semi-insulator. This gives the first antireflection layer 15 good passivation capabilities, which helps reduce carrier recombination. Simultaneously, it improves the chemical stability of the first antireflection layer 15, making it less susceptible to external environmental factors and enhancing its reliability.

[0038] In related technologies, transparent conductive layers (TCO layers) are disposed on the first and second passivation contact structures of back-contact solar cells, and the first and second electrodes are electrically connected to the transparent conductive layers. The transparent conductive layers have high light transmittance and can reduce light reflection. They also collect and transport charge carriers. However, the transparent conductive layers suffer from severe parasitic light absorption, increasing the light absorption loss of the back-contact solar cell and affecting its efficiency. Furthermore, the transparent conductive layers require isolation structures (such as trenches) to separate the portions of the transparent conductive layers on the first passivation contact structure from those on the second passivation contact structure, reducing the risk of short circuits. The isolation structure complicates the fabrication process of the transparent conductive layers, increasing the difficulty of manufacturing back-contact solar cells. In addition, the transparent conductive layers have low chemical stability, readily reacting with water or oxygen, and the raw materials are expensive.

[0039] Compared to related technologies, the back-contact solar cell 10 of this application embodiment is provided with a carrier transport layer 14 and a first antireflection layer 15, eliminating the need for a transparent conductive layer. The first antireflection layer 15 reduces light reflection and increases the light transmittance of the back-contact solar cell 10 surface. The first antireflection layer 15 can be a non-metallic film layer such as silicon nitride. Compared to a transparent conductive layer, the first antireflection layer 15 has weaker parasitic light absorption and less light absorption loss. Furthermore, the first antireflection layer 15 has excellent passivation effects, reducing carrier recombination and thus improving the efficiency of the back-contact solar cell 10. Simultaneously, the weak conductivity of the first antireflection layer 15 eliminates the need for an isolation structure, reducing the risk of short circuits in the back-contact solar cell and simplifying the fabrication process. Moreover, the first antireflection layer 15 has higher chemical stability, lower fabrication costs, and a more mature fabrication process, facilitating large-scale mass production.

[0040] The carrier transport layer 14 is relatively thin, allowing carriers to pass through via quantum tunneling, thus ensuring the normal operation of the first electrode 16 and the second electrode 17. The carrier transport layer 14 also acts as a barrier to the metal elements in the first electrode 16 and the second electrode 17, reducing the risk of diffusion of these elements towards the substrate 11 and causing structural damage. Simultaneously, it ensures the passivation effect of the first passivation contact structure 12 and the second passivation contact structure 13, improving the efficiency of the back-contact solar cell 10. Because the carrier transport layer 14 has relatively low conductivity, it does not require an isolation structure, simplifying the fabrication process of the back-contact solar cell 10 and reducing its manufacturing difficulty.

[0041] In summary, by setting a carrier transport layer and a first anti-reflection layer, the embodiments of this application eliminate the need for a transparent conductive layer in back-contact solar cells, which is beneficial for improving the photoelectric conversion efficiency of back-contact solar cells, simplifying the fabrication process of back-contact solar cells, and reducing the production cost of back-contact solar cells.

[0042] Continue as Figure 1As shown, in some embodiments, during the fabrication of the back-contact solar cell 10, a carrier transport layer 14 is first formed on the second surface 112, that is, the carrier transport layer 14 is formed on the first passivation contact structure 12 and the second passivation contact structure 13. Then, a first electrode 16 and a second electrode 17 are fabricated on the carrier transport layer 14 to achieve electrical connection between the first electrode 16 and the first passivation contact structure 12, and electrical connection between the second electrode 17 and the second passivation contact structure 13. Then, a first antireflection layer 15 is fabricated. In some embodiments, the carrier transport layer 14 and the first antireflection layer 15 can be fabricated by methods such as evaporation, sputtering, atomic layer deposition, plasma-enhanced chemical vapor deposition, low-pressure chemical vapor deposition, plasma-enhanced atomic layer deposition, and thermal oxidation.

[0043] Continue as Figure 1 As shown, in some possible embodiments, the back contact solar cell 10 further includes a passivation layer 181 and a second antireflection layer 182. The passivation layer 181 is disposed on the second surface 112, and the second antireflection layer 182 is disposed along the first direction Z on the side of the passivation layer 181 away from the substrate 11.

[0044] In this embodiment, the passivation layer 181 may include at least one of aluminum oxide, silicon oxide, and hydrogenated amorphous silicon. The second antireflection layer 182 may include at least one of silicon nitride, silicon oxynitride, and silicon oxide. The presence of the passivation layer 181 and the second antireflection layer 182 helps to enhance the carrier concentration on the surface of the back contact solar cell 10, thereby increasing the short-circuit current and open-circuit voltage of the back contact solar cell 10, and thus improving the cell efficiency.

[0045] Continue as Figure 1 As shown, in some possible embodiments, the back-contact solar cell 10 is a hybrid back-contact solar cell. The first passivation contact structure 12 includes a tunneling oxide layer 121 and an N-type doped layer 122 arranged in a first direction Z. The N-type doped layer 122 is located on the side of the tunneling oxide layer 121 away from the substrate 11. The first electrode 16 is located on the N-type doped layer 122 and is electrically connected to the N-type doped layer 122.

[0046] In this embodiment, the tunneling oxide layer 121 may include at least one of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, amorphous silicon, and polycrystalline silicon. The lattice of the tunneling oxide layer 121 can be well matched with the lattice of the substrate 11, that is, the tunneling oxide layer 121 can effectively passivate the first surface 111 of the substrate 11 to reduce the recombination rate of photogenerated electrons and holes on the first surface 111 of the substrate 11. The N-type doped layer 122 may include at least one of N-type doped amorphous silicon, N-type doped polycrystalline silicon, N-type doped microcrystalline silicon, and N-type doped silicon carbide. The N-type doped layer 122 can provide a field passivation effect, thereby reducing the carrier recombination rate at the interface of the substrate 11, and thus improving the open-circuit voltage, short-circuit current, and fill factor of the back contact solar cell 10.

[0047] The second passivated contact structure 13 includes a doped amorphous silicon layer 131 and a P-type doped layer 132 arranged along the first direction Z. The P-type doped layer 132 is located on the side of the doped amorphous silicon layer 131 away from the substrate 11. The second electrode 17 is located on the P-type doped layer 132 and is electrically connected to the P-type doped layer 132.

[0048] In some embodiments, the P-type doped layer 132 may be a P-type doped amorphous silicon layer, specifically, the P-type doped layer 132 may be a P-type hydrogenated amorphous silicon layer. In some embodiments, the P-type doped layer 132 may be a P-type doped microcrystalline silicon layer. In some embodiments, the doped amorphous silicon layer 131 is doped with P-type elements, that is, the doped amorphous silicon layer 131 is a P-type doped amorphous silicon layer.

[0049] In summary, the back-contact solar cell in this application embodiment can be a hybrid back-contact cell employing tunnel oxide passivation contact cell technology and heterojunction cell technology, and the hybrid back-contact cell has a high photoelectric conversion efficiency.

[0050] Continue as Figure 1 As shown, in some possible implementations, the thickness of the carrier transport layer 14 along the first direction Z is D1, and the thickness of the first anti-reflection layer 15 along the first direction Z is D2, where D1 and D2 satisfy: 0.005≤D1 / D2≤0.03.

[0051] In this embodiment, the ratio of the thickness D1 of the carrier transport layer 14 to the thickness D2 of the first antireflection layer 15 can be 0.005, 0.006, 0.008, 0.01, 0.012, 0.014, 0.016, 0.018, 0.02, 0.025, or 0.03, or other values ​​within the aforementioned range. The thickness of the carrier transport layer 14 is designed to be relatively thin so that carriers can pass through through the quantum tunneling effect, thereby achieving carrier transport. If the thickness of the first antireflection layer 15 is too large when the thickness of the carrier transport layer 14 is constant, i.e. the ratio of D1 to D2 is too small, the reflectivity of the first antireflection layer 15 will increase and the photoparasitic absorption will increase. This will lead to a decrease in the short-circuit current of the back contact solar cell 10 and a decrease in the photoelectric conversion efficiency of the back contact solar cell 10. It will also affect the mechanical properties of the first antireflection layer 15, causing the first antireflection layer 15 to crack or fall off from the carrier transport layer 14, thereby affecting the reliability and service life of the back contact solar cell 10. If the thickness of the first antireflection layer 15 is too small, i.e. the ratio of D1 to D2 is too large, the reflectivity of the first antireflection layer 15 will also increase, which will reduce the short-circuit current of the back contact solar cell 10 and reduce the photoelectric conversion efficiency of the back contact solar cell 10. Therefore, by limiting the ratio of the thickness D1 of the carrier transport layer 14 to the thickness D2 of the first antireflection layer 15, the reliability of the carrier transport layer 14 and the first antireflection layer 15 can be guaranteed, thereby improving the photoelectric conversion efficiency and service life of the back contact solar cell 10.

[0052] Continue as Figure 1 As shown, in some possible implementations, the thickness of the carrier transport layer 14 along the first direction Z is D1, which satisfies: 1nm≤D1≤2nm.

[0053] In this embodiment, the thickness D1 of the carrier transport layer 14 can be 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm, or 2 nm, or other values ​​within the aforementioned range. By limiting the thickness of the carrier transport layer 14, the blocking effect of the carrier transport layer 14 on metal elements is achieved while ensuring that carriers can be transported effectively.

[0054] Continue as Figure 1 As shown, in some possible embodiments, the carrier transport layer 14 includes at least one of silicon oxide, titanium oxide, and nickel oxide.

[0055] In this embodiment, the carrier transport layer 14 uses the aforementioned material to provide reliable blocking performance, reducing the risk of metal elements in the first electrode 16 and the second electrode 17 diffusing towards the substrate 11 and causing damage to the structure of the substrate 11. At the same time, the aforementioned material has weak conductivity, so that the carrier transport layer 14 does not need to set an isolation structure between the first passivation contact structure 12 and the second passivation contact structure 13, which can also reduce the risk of short circuit in the back contact solar cell, thereby simplifying the fabrication process of the back contact solar cell 10 and reducing the fabrication difficulty of the back contact solar cell 10.

[0056] Continue as Figure 1 As shown, in some possible implementations, the first antireflection layer 15 includes a silicon nitride layer 151, the thickness of which along the first direction Z is D3, and D3 satisfies: 60nm≤D3≤90nm.

[0057] In this embodiment, the first antireflection layer 15 can be a single-layer structure, and the thickness of the silicon nitride layer 151 along the first direction Z is the thickness of the first antireflection layer 15 along the first direction Z. The silicon nitride layer 151 not only has good antireflection capability but also excellent passivation capability, thereby improving the short-circuit current, open-circuit voltage, and fill factor of the back contact solar cell 10. The silicon nitride layer 151 has relatively stable chemical properties, which can protect the surface of the back contact solar cell 10 and extend its lifespan.

[0058] The thickness of the silicon nitride layer 151 along the first direction Z is D3, which can be 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, or 90nm, or other values ​​within the aforementioned range. If the thickness of the silicon nitride layer 151 is too small, its anti-reflection effect will deteriorate, and its passivation effect will be poor. If the thickness of the silicon nitride layer 151 is too large, its anti-reflection effect will also deteriorate, and its structural stability will decrease, making it prone to cracking or even detachment, thus affecting the reliability and yield of the back contact solar cell 10. Therefore, by setting the thickness of the silicon nitride layer 151, the passivation effect and structural stability of the silicon nitride layer 151 can be improved while ensuring its anti-reflection effect, thereby improving the efficiency, yield, and reliability of the back contact solar cell 10.

[0059] In some embodiments, the silicon nitride layer may include a plurality of sublayers arranged along a first direction, wherein the refractive index of the plurality of sublayers decreases toward the direction away from the substrate. Specifically, as Figure 2 As shown, the silicon nitride layer 151 may include a first sublayer 1511, a second sublayer 1512, and a third sublayer 1513 arranged along the first direction Z. Please also refer to... Figure 1The first sublayer 1511 is located on the side of the second sublayer 1512 closer to the substrate 11, and the third sublayer 1513 is located on the side of the second sublayer 1512 away from the substrate 11. The first sublayer 1511, the second sublayer 1512, and the third sublayer 1513 are all silicon nitride. The reflectivity of the first sublayer 1511 is greater than that of the second sublayer 1512, and the reflectivity of the second sublayer 1512 is greater than that of the third sublayer 1513. This arrangement improves the overall anti-reflection efficiency of the silicon nitride layer 151, thereby improving the photoelectric conversion efficiency of the back contact solar cell 10.

[0060] like Figure 3 As shown, in some possible embodiments, the first antireflection layer 15 includes a silicon nitride layer 151 and a silicon oxynitride layer 152 arranged along the first direction Z. The silicon oxynitride layer 152 is located on the side of the silicon nitride layer 151 away from the substrate 11, and the thickness of the silicon oxynitride layer 152 is less than the thickness of the silicon nitride layer 151.

[0061] In this embodiment, the first antireflection layer 15 can have a stacked structure. By controlling the thickness of the silicon oxynitride layer 152 and the silicon nitride layer 151, their reflectivity can be adjusted, resulting in a gradient change in the reflectivity of the first antireflection layer 15. For example, the refractive index of the silicon oxynitride layer 152 can be less than that of the silicon nitride layer 151. Compared to the first antireflection layer 15 being only a silicon nitride layer 151 or only a silicon nitride layer 151, the stacking of silicon oxynitride layer 152 and silicon nitride layer 151 improves the antireflection effect of the first antireflection layer 15, allowing more photons to enter the back contact solar cell 10. Simultaneously, it reduces the parasitic absorption loss of the first antireflection layer 15, improving the optical response of the back contact solar cell 10. Furthermore, the silicon nitride layer 151 and the silicon oxynitride layer 152 possess excellent passivation properties, which helps reduce the recombination rate of charge carriers on the surface of the substrate 11, improving the open-circuit voltage and fill factor of the back contact solar cell 10.

[0062] Continue as Figure 3 As shown, in some possible embodiments, the first antireflection layer 15 includes a silicon nitride layer 151 and a silicon oxynitride layer 152 arranged along the first direction Z, wherein the thickness of the silicon nitride layer 151 along the first direction Z is D3, and D3 satisfies: 45nm≤D3≤65nm, and the thickness of the silicon oxynitride layer 152 along the first direction Z is D4, and D4 satisfies: 20nm≤D4≤45nm.

[0063] The thickness D3 of the silicon nitride layer 151 can be 45nm, 46nm, 48mm, 50mm, 52mm, 54mm, 56mm, 60mm, 62mm, 64mm or 65mm, or other values ​​within the above range.

[0064] The thickness D4 of the silicon oxynitride layer 152 can be 20nm, 22nm, 24nm, 26nm, 28nm, 30nm, 32nm, 34nm, 36nm, 38nm, 40nm, 42nm, 44mm or 45mm, or other values ​​within the above range.

[0065] By limiting the thickness of the silicon oxide layer 153 and the silicon oxynitride layer 152, the passivation effect and structural stability of the silicon nitride layer 151 and the silicon oxynitride layer 152 are improved while ensuring the anti-reflection effect of the silicon nitride layer 151 and the silicon oxynitride layer 152, thereby improving the efficiency, yield and reliability of the back contact solar cell 10.

[0066] like Figure 4 As shown, in some possible embodiments, the first antireflection layer 15 includes a silicon nitride layer 151, a silicon oxynitride layer 152, and a silicon oxide layer 153 arranged along the first direction Z. The silicon nitride layer 151 is located on the side of the silicon oxynitride layer 152 facing the substrate 11, and the silicon oxide layer 153 is located on the side of the silicon oxynitride layer 152 away from the substrate 11. The thickness of the silicon oxynitride layer 152 is less than the thickness of the silicon nitride layer 151, and the thickness of the silicon oxide layer 153 is less than the thickness of the silicon oxynitride layer 152.

[0067] By controlling the thicknesses of the silicon oxynitride layer 152, silicon nitride layer 151, and silicon oxide layer 153, the reflectivity of these three layers can be adjusted, resulting in a gradient change in the reflectivity of the first antireflection layer 15. Optionally, the refractive index of the silicon oxynitride layer 152 can be less than that of the silicon nitride layer 151, and the refractive index of the silicon oxide layer 153 can be less than that of the silicon oxynitride layer 152. The stacking of the silicon oxynitride layer 152, silicon nitride layer 151, and silicon oxide layer 153 improves the antireflection effect of the first antireflection layer 15, allowing more photons to enter the back contact solar cell 10. Simultaneously, it reduces the parasitic absorption loss of the first antireflection layer 15, improving the optical response of the back contact solar cell 10. Furthermore, the stacked design of the three layers allows for stress balance within the first antireflection layer 15, thereby improving its stability and enabling it to adhere stably to the carrier transport layer 14, thus enhancing the mechanical properties of the back contact solar cell 10.

[0068] Continue as Figure 4As shown, in some possible embodiments, the first antireflection layer 15 includes a silicon nitride layer 151, a silicon oxynitride layer 152, and a silicon oxide layer 153 arranged along the first direction Z. The thickness of the silicon nitride layer 151 along the first direction Z is D3, where D3 satisfies: 40nm≤D3≤60nm. The thickness of the silicon oxynitride layer 152 along the first direction Z is D4, where D4 satisfies: 20nm≤D4≤40nm. The thickness of the silicon oxide layer 153 along the first direction Z is D5, where D5 satisfies: 10nm≤D4≤20nm.

[0069] The thickness D3 of the silicon nitride layer 151 can be 40nm, 42nm, 44nm, 46nm, 48nm, 50nm, 52nm, 54nm, 56nm, 58nm or 60nm, or other values ​​within the above range.

[0070] The thickness D4 of the silicon oxynitride layer 152 can be 20nm, 22nm, 24nm, 26nm, 28nm, 30nm, 32nm, 34nm, 36nm, 38nm or 40nm, or other values ​​within the above range.

[0071] The thickness D5 of the silicon oxide layer 153 can be 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm or 20nm, or other values ​​within the above range.

[0072] It should be noted that the silicon oxide layer 153 in this embodiment may refer to a silicon oxide layer containing a certain amount of nitrogen, such as a nitrogen atom content of less than 10% (the corresponding atomic content is obtained by EDS or EELS testing). Those skilled in the art would consider this layer to be a silicon oxide layer.

[0073] By limiting the thickness of the silicon nitride layer 151, silicon oxynitride layer 152, and silicon oxide layer 153, the overall stability of the first antireflection layer 15 is improved while ensuring the antireflection effect of the silicon nitride layer 151, silicon oxynitride layer 152, and silicon oxide layer 153. This allows it to be stably attached to the carrier transport layer 14, thereby improving the mechanical properties of the back contact solar cell 10.

[0074] Continue as Figure 4As shown, in some possible embodiments, the first passivation contact structure 12 includes a first sub-part 12a and a second sub-part 12b arranged along the second direction X, and the second passivation contact structure 13 includes a third sub-part 13a and a fourth sub-part 13b arranged along the second direction X. The third sub-part 13a is stacked along the first direction Z on the side of the first sub-part 12a away from the substrate 11. The projection of the first electrode 16 along the first direction Z is located within the projection of the second sub-part 12b along the first direction Z, and the projection of the second electrode 17 along the first direction Z is located within the projection of the fourth sub-part 13b along the first direction Z.

[0075] In this embodiment, the third sub-part 13a is stacked on the first sub-part 12a, causing partial electrical connection between the first passivation contact structure 12 and the second passivation contact structure 13 to form a reverse leakage path, reducing the risk of hot spot effect when the back contact solar cell 10 is shaded. The projection of the first electrode 16 along the first direction Z is located within the projection of the second sub-part 12b along the first direction Z, and the projection of the second electrode 17 along the first direction Z is located within the projection of the fourth sub-part 13b along the first direction Z. That is, the first electrode 16 and the second electrode 17 are not located at the overlap of the first passivation contact structure 12 and the second passivation contact structure 13, thereby improving the reliability of the back contact solar cell 10.

[0076] like Figure 5 As shown, in some possible implementations, the distance from the first portion 1111 along the first direction Z to the second surface 112 is greater than the distance from the second portion 1112 along the first direction Z to the second surface 112.

[0077] In this embodiment, the first part 1111 and the second part 1112 have a height difference in the first direction Z. Please refer to [the relevant documentation / reference]. Figure 4 This allows the height of the substrate 11 corresponding to the first passivation contact structure 12 to be greater than the height of the substrate 11 corresponding to the second passivation contact structure 13. This enables a height difference between the first passivation contact structure 12 and the second passivation contact structure 13, and between the first electrode 16 and the second electrode 17. This reduces the risk of mutual interference between the first electrode 16 and the second electrode 17, thereby reducing the risk of short circuit in the back contact solar cell 10 and improving the reliability of the back contact solar cell 10.

[0078] In some embodiments, the height difference between the first portion 1111 and the second portion 1112 along the first direction Z can be 4μm to 6μm, for example, 4μm, 4.5μm, 5μm, 5.2μm, 5.4μm, 5.5μm, 5.6μm, 5.8μm or 6μm, or other values ​​within the above range.

[0079] like Figure 6As shown, in some embodiments, the width of the second portion 1112 along the second direction X can be greater than the width of the first portion 1111 along the second direction X. The width of the second passivation contact structure 13 along the second direction X can be greater than the width of the first passivation contact structure 12 along the second direction X, and the width of the second electrode 17 along the second direction X can be greater than the width of the first electrode 16 along the second direction X. The larger width of the second portion 1112 results in a larger area for the second passivation contact structure 13, and facilitates increasing the width of the second electrode 17, thereby increasing the contact area of ​​the second electrode 17 and improving the current collection and conduction efficiency.

[0080] In some embodiments, the width W1 of the first electrode 16 along the second direction X satisfies: 5μm≤W1≤60μm. For example, W1 can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm or 60μm, or other values ​​within the above range.

[0081] In some embodiments, the height H1 of the first electrode 16 along the first direction Z satisfies: 5μm≤H1≤20μm. For example, H1 can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, or other values ​​within the above range.

[0082] In some embodiments, the width W2 of the second electrode 17 along the second direction X satisfies: 5μm≤W2≤60μm. For example, W2 can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm or 60μm, or other values ​​within the above range.

[0083] In some embodiments, the height H2 of the second electrode 17 along the second direction X satisfies: 5μm≤H2≤20μm. For example, H2 can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, or other values ​​within the above range.

[0084] In other embodiments, the width of the second portion along the second direction may be less than or equal to the width of the first portion along the second direction. The width of the second passivation contact structure along the second direction may be less than or equal to the width of the first passivation contact structure along the second direction, and the width of the second electrode along the second direction may be less than or equal to the width of the first electrode along the second direction.

[0085] In some possible implementations, the first and / or second portions have a pyramidal microstructure. A pyramidal microstructure can be obtained by texturing the first surface, thereby reducing the reflectivity of the first surface, increasing light absorption, and consequently improving the short-circuit current and photoelectric conversion efficiency of the back-contact solar cell.

[0086] Specifically, such as Figure 6 As shown, the first part 1111 can have a planar structure, and the second part 1112 can have a pyramid-shaped microstructure. That is, the first part 1111 is a polished surface, and the second part 1112 is a textured surface, so that the surface area of ​​the second part 1112 is greater than the surface area of ​​the first part 1111. Under the same process conditions, the thickness of the carrier transport layer 14 on the first part 1111 can be greater than or equal to the thickness of the carrier transport layer 14 on the second part 1112, and the thickness of the first anti-reflection layer 15 on the first part 1111 can be greater than or equal to the thickness of the carrier transport layer 14 on the second part 1112. In other words, the carrier transport layer 14 and the first anti-reflection layer 15 can be films with uniform thickness or films with non-uniform thickness.

[0087] In some embodiments, the thickness of the carrier transport layer 14 on the first portion 1111 along the first direction Z is D11, and the thickness of the carrier transport layer 14 on the second portion 1112 is D12. The ratio of D12 to D11 can be from 0.7 to 1, for example, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.

[0088] In some embodiments, the thickness of the first antireflection layer 15 on the first portion 1111 along the first direction Z is D21, and the thickness of the carrier transport layer 14 on the second portion 1112 along the first direction Z is D22. The ratio of D21 to D22 can be from 0.7 to 1, for example, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.

[0089] In some embodiments, the thickness of the second electrode 17 along the first direction Z can be less than the thickness of the first electrode 16 along the first direction Z, and the width of the second electrode 17 along the second direction X can be greater than the width of the first electrode 16 along the second direction X. This allows the metal paste of the second electrode 17 to be better extended on the pyramid-shaped microstructure of the second part 1112 during electrode fabrication, thereby increasing the contact area of ​​the second electrode 17, reducing the contact resistance, and also reducing the difficulty of electrode fabrication.

[0090] In other embodiments, the thickness of the second electrode along the first direction may be equal to or greater than the thickness of the first electrode along the first direction.

[0091] Continue as Figure 6As shown, in some embodiments, the second surface 112 has a pyramid-shaped microstructure to reduce the reflectivity of the second surface 112, increase the light absorption effect, and thereby improve the short-circuit current and photoelectric conversion efficiency of the back contact solar cell.

[0092] like Figure 7 As shown, in some embodiments, the distance from the first portion 1111 along the first direction Z to the second surface 112 may be equal to the distance from the second portion 1112 along the first direction Z to the second surface 112. The second surface 112 may have a planar structure.

[0093] In some embodiments, the distance from the first portion to the second surface along the first direction may be less than the distance from the second portion to the second surface along the first direction.

[0094] In some embodiments, the first part has a pyramid-shaped microstructure and the second part has a planar structure.

[0095] In some embodiments, both the first part and the second part have pyramid-shaped microstructures, that is, both the first part and the second part are velvety.

[0096] In some embodiments, both the first part and the second part have a planar structure, that is, both the first part and the second part are polished surfaces.

[0097] like Figure 8 As shown, in some possible embodiments, the first surface 111 of the substrate 11 further includes a third portion 1113 located between the first portion 1111 and the second portion 1112. An insulating structure 19 is disposed on the third portion 1113, located between the first passivated contact structure 12 and the second passivated contact structure 13. The insulating structure 19 isolates and insulates the first passivated contact structure 12 and the second passivated contact structure 13 to reduce the risk of leakage between them.

[0098] Optionally, the insulating structure 19 may have one or more insulating layers. In addition to providing isolation, the insulating layers can also act as passivation and antireflection films, thereby improving the photoelectric conversion efficiency of the back-contact solar cell 10. Specifically, the insulating structure has two insulating layers arranged along a first direction, namely a first insulating layer and a second insulating layer. The second insulating layer is located on the side of the first insulating layer away from the substrate. The first insulating layer can be a passivation film layer, such as one or a combination of silicon oxide, silicon nitride, silicon oxynitride, titanium oxide, and aluminum oxide. The second insulating layer can be an antireflection film layer, such as one or a combination of silicon nitride, silicon oxynitride, and silicon oxide.

[0099] Optionally, the aforementioned carrier transport layer and the first anti-reflection layer are disposed on the third part. Since the carrier transport layer and the first anti-reflection layer have weak conductivity, they can also serve as insulation and isolation.

[0100] Optionally, the third part may have a pyramid-shaped microstructure, or the third part may be a planar structure.

[0101] This application provides a solar tandem cell, including a crystalline silicon bottom cell and a perovskite top cell. The crystalline silicon bottom cell includes the aforementioned back-contact solar cell, and the perovskite top cell is electrically connected to the crystalline silicon bottom cell.

[0102] like Figure 9 As shown, in some embodiments, a composite layer 30 is provided between the perovskite top cell 20 and the back contact solar cell 10 (i.e., the crystalline silicon bottom cell). The composite layer 30 can be a transparent conductive oxide, such as ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), FTO (fluorine-doped tin oxide), or ATO (antimony-doped tin oxide).

[0103] The perovskite top solar cell 20 includes a first transport layer 21, a perovskite layer 22, a second transport layer 23, a transparent conductive layer 24, and a third electrode 25 arranged along a first direction Z. One of the first transport layer 21 and the second transport layer 23 is an electron transport layer, and the other is a hole transport layer. The electron transport layer can be a metal oxide or a fullerene derivative, and the hole transport layer can be a metal oxide or a SAM (self-assembled molecular layer). The transparent conductive layer 24 can be IZO (indium zinc oxide), a transparent conductive oxide. The third electrode 25 is disposed on the transparent conductive layer 24 and electrically connected to it. The third electrode 25 can be sintered from a metal paste, which can include at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

[0104] The perovskite material in the perovskite top cell 20 has a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrodes with low loss. Therefore, it can generate high photogenerated voltage and current, making the perovskite exhibit high photoelectric conversion efficiency.

[0105] By combining the aforementioned back-contact solar cell 10 and perovskite top cell 20 into a tandem cell, a wider range of solar spectrum absorption can be achieved, thereby improving the photoelectric conversion efficiency of the tandem cell. Since the back-contact solar cell 10 has the aforementioned technical effects, the tandem cell with this back-contact solar cell 10 also has the aforementioned technical effects, which will not be elaborated further here.

[0106] This application provides a photovoltaic module, which includes a cover plate, an encapsulation layer, and a battery string. The battery string includes multiple back-contact solar cells as described above, or the battery string includes multiple solar tandem cells as described above.

[0107] like Figure 10 As shown, in some embodiments, the cover plate at the top of the photovoltaic module 100 is a first cover plate 101, the cover plate at the bottom of the photovoltaic module 100 is a second cover plate 105, the encapsulation layer between the first cover plate 101 and the battery string 103 is a first encapsulation layer 102, and the encapsulation layer between the second cover plate 105 and the battery string 103 is a second encapsulation layer 104. The first cover plate 101, the first encapsulation layer 102, the battery string 103, the second encapsulation layer 104, and the second cover plate 105 can be arranged along the thickness direction of the photovoltaic module 100 and laminated together. The first cover plate 101 can be a glass cover plate with high light transmittance. The first encapsulation layer 102 bonds the first cover plate 101 to the battery string 103 to encapsulate and protect the battery string 103. The material of the first encapsulation layer 102 can be one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB). The second encapsulation layer 104 connects the battery string 103 to the second cover plate 105, and also provides encapsulation and protection for the battery string 103. The material of the second encapsulation layer 104 can be one or more of the aforementioned EVA, POE, and PVB. The material of the second cover plate 105 can be glass, or the second cover plate 105 can also be composed of multiple polymer film layers.

[0108] The above description is merely an optional embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A back-contact solar cell, characterized in that, include: The substrate includes a first surface and a second surface disposed opposite to each other along a first direction. The first surface includes a first portion and a second portion arranged alternately along a second direction. A first passivation contact structure is disposed on the first portion, and a second passivation contact structure is disposed on the second portion. A charge carrier transport layer is located on the side of the first passivated contact structure and the second passivated contact structure opposite to the substrate; A first anti-reflection layer is located on the side of the carrier transport layer opposite to the substrate; A first electrode is located on the carrier transport layer, the projection of the first electrode along the first direction is located within the projection of the first passivation contact structure along the first direction, and the first electrode is electrically connected to the first passivation contact structure. The second electrode is located on the carrier transport layer. The projection of the second electrode along the first direction is located within the projection of the second passivation contact structure along the first direction, and the second electrode is electrically connected to the second passivation contact structure.

2. The back-contact solar cell according to claim 1, characterized in that, The first passivated contact structure includes a tunneling oxide layer and an N-type doped layer arranged in the first direction. The N-type doped layer is located on the side of the tunneling oxide layer away from the substrate, and the first electrode is electrically connected to the N-type doped layer. The second passivated contact structure includes a doped amorphous silicon layer and a P-type doped layer arranged along the first direction. The P-type doped layer is located on the side of the doped amorphous silicon layer away from the substrate, and the second electrode is electrically connected to the P-type doped layer.

3. The back-contact solar cell according to claim 1, characterized in that, The thickness of the charge carrier transport layer along the first direction is D1, and the thickness of the first anti-reflection layer along the first direction is D2. D1 and D2 satisfy: 0.005≤D1 / D2≤0.

03.

4. The back-contact solar cell according to claim 3, characterized in that, The thickness D1 of the carrier transport layer along the first direction satisfies: 1nm≤D1≤2nm.

5. The back-contact solar cell according to claim 3, characterized in that, The carrier transport layer comprises at least one of silicon oxide, titanium oxide, and nickel oxide.

6. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The first antireflection layer includes a silicon nitride layer; The thickness of the silicon nitride layer along the first direction is D3, and D3 satisfies: 60nm≤D3≤90nm.

7. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The first antireflection layer includes a silicon nitride layer and a silicon oxynitride layer arranged along the first direction, wherein the silicon oxynitride layer is located on the side of the silicon nitride layer opposite to the substrate; The thickness of the silicon oxynitride layer is less than the thickness of the silicon nitride layer.

8. The back-contact solar cell according to claim 7, characterized in that, The thickness of the silicon nitride layer along the first direction is D3, and D3 satisfies: 45nm≤D3≤65nm; The thickness of the silicon oxynitride layer along the first direction is D4, and D4 satisfies: 20nm≤D4≤45nm.

9. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The first antireflection layer includes a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer arranged along the first direction. The silicon nitride layer is located on the side of the silicon oxynitride layer facing the substrate, and the silicon oxide layer is located on the side of the silicon oxynitride layer away from the substrate. The thickness of the silicon oxynitride layer is less than the thickness of the silicon nitride layer, and the thickness of the silicon oxide layer is less than the thickness of the silicon oxynitride layer.

10. The back-contact solar cell according to claim 9, characterized in that, The thickness of the silicon nitride layer along the first direction is D3, and D3 satisfies: 40nm≤D3≤60nm; The thickness of the silicon oxynitride layer along the first direction is D4, and D4 satisfies: 20nm≤D4≤40nm; The thickness of the silicon oxide layer along the first direction is D5, and D5 satisfies: 10nm≤D4≤20nm.

11. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The first passivated contact structure includes a first sub-part and a second sub-part arranged along the second direction; The second passivated contact structure includes a third sub-part and a fourth sub-part arranged along the second direction, wherein the third sub-part is stacked along the first direction on the side of the first sub-part facing away from the substrate; The projection of the first electrode along the first direction lies within the projection of the second sub-part along the first direction; The projection of the second electrode along the first direction lies within the projection of the fourth sub-part along the first direction.

12. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The distance from the first portion to the second surface along the first direction is greater than the distance from the second portion to the second surface along the first direction.

13. The back-contact solar cell according to claim 12, characterized in that, The first part and / or the second part have a pyramid-shaped microstructure.

14. The back-contact solar cell according to any one of claims 1 to 5, characterized in that, The back contact solar cell also includes a passivation layer and a second anti-reflection layer; The passivation layer is disposed on the second surface, and the second antireflection layer is disposed along the first direction on the side of the passivation layer opposite to the substrate.

15. The back-contact solar cell according to claim 14, characterized in that, The passivation layer includes at least one of aluminum oxide, silicon oxide, and hydrogenated amorphous silicon. The second antireflection layer includes at least one of silicon nitride, silicon oxynitride, and silicon oxide.

16. A solar tandem battery, characterized in that, include: A crystalline silicon bottom cell, the crystalline silicon bottom cell comprising a back-contact solar cell according to any one of claims 1 to 15; A perovskite top cell, wherein the perovskite top cell is electrically connected to the crystalline silicon bottom cell.

17. A photovoltaic module, characterized in that, The photovoltaic module includes a cover plate, an encapsulation layer, and a battery string, wherein the battery string includes a plurality of back-contact solar cells as described in any one of claims 1 to 15, or the battery string includes a plurality of solar tandem cells as described in claim 16.

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