Solar cell, photovoltaic module and photovoltaic system

Abstract

The utility model relates to a solar cell, a photovoltaic module and a photovoltaic system. The solar cell comprises a substrate, a first doping layer and a first passivation layer are sequentially stacked on a first surface of the substrate, a tunneling layer, a second doping layer and a second passivation layer are sequentially stacked on a second surface of the substrate, and the first surface and the second surface are oppositely arranged; the barrier layer is arranged between the first doping layer and the first passivation layer, or the barrier layer is arranged between the second doping layer and the second passivation layer, and the barrier layer is configured to allow holes to pass through and inhibit electrons to pass through. Therefore, while the production efficiency of the solar cell is improved, the open-circuit voltage of the solar cell is improved, so that the solar cell keeps higher photoelectric conversion efficiency.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a solar cell, a photovoltaic module and a photovoltaic system. Background Art

[0002] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electrical energy. As they are green and environmentally friendly products that do not cause environmental pollution, and solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.

[0003] At present, the mainstream batteries include tunnel oxide passivated contact batteries (TOPCon), interdigitated back contact batteries (IBC) and heterojunction batteries (HJT). The passivation contact structure composed of tunnel oxide layer and doped polysilicon layer in TOPCon (Tunnel Oxide passivated contact) batteries can effectively reduce the recombination rate between silicon wafer surface and metal contact, making TOPCon batteries one of the hot directions of high conversion efficiency silicon-based solar cells.

[0004] In the related art, a TOPCon cell is provided with a passivation layer only on its light-receiving surface. This can improve the open circuit voltage of the TOPCon cell and enable the TOPCon cell to maintain a relatively high photoelectric conversion efficiency, but it will reduce the production efficiency of the TOPCon cell. Summary of the invention

[0005] Based on this, the present application provides a solar cell, a photovoltaic module and a photovoltaic system to improve the open circuit voltage of the solar cell while improving the production efficiency of the solar cell, so that the solar cell maintains a high photoelectric conversion efficiency.

[0006] An embodiment of the first aspect of the present application provides a solar cell, comprising a substrate, a first doping layer and a first passivation layer are stacked in sequence on the first surface of the substrate, a tunneling layer, a second doping layer and a second passivation layer are stacked in sequence on the second surface of the substrate, and the first surface and the second surface are arranged opposite to each other; a barrier layer is arranged between the first doping layer and the first passivation layer, or the barrier layer is arranged between the second doping layer and the second passivation layer, and the barrier layer is configured to allow holes to pass through and inhibit electrons from passing through.

[0007] In some embodiments, the material of the barrier layer includes at least one of molybdenum oxide and nickel oxide.

[0008] In some embodiments, the barrier layer has a thickness of 10 nm to 20 nm.

[0009] In some embodiments, the first passivation layer and the second passivation layer are both made of aluminum oxide.

[0010] In some embodiments, the thickness of the first passivation layer and the second passivation layer are both 4 nm to 5 nm.

[0011] In some of the embodiments, a first anti-reflection layer and a second anti-reflection layer are further included, wherein the first anti-reflection layer is disposed on a side of the first passivation layer away from the substrate; and the second anti-reflection layer is disposed on a side of the second passivation layer away from the substrate.

[0012] In some embodiments, the thickness of the first anti-reflection layer and the second anti-reflection layer are both 60nm to 90nm; and / or; the material of the first anti-reflection layer and the second anti-reflection layer includes at least one of aluminum oxide, silicon nitride, silicon oxide, gallium oxide, aluminum nitride, and silicon oxynitride.

[0013] In some embodiments, a first electrode and a second electrode are further included, wherein the first electrode is located on a side of the first passivation layer away from the substrate and is electrically connected to the first doped layer, and the second electrode is located on a side of the second passivation layer away from the substrate and is electrically connected to the second doped layer.

[0014] An embodiment of a second aspect of the present application provides a photovoltaic assembly, comprising the solar cell according to the first aspect.

[0015] An embodiment of a third aspect of the present application provides a photovoltaic system, comprising the photovoltaic component according to the first aspect.

[0016] The above-mentioned solar cell is formed by stacking a first doping layer and a first passivation layer on the first surface of the substrate in sequence, and a tunneling layer, a second doping layer and a second passivation layer on the second surface of the substrate in sequence, that is, the solar cell has a double-sided passivation layer, thereby, the first passivation layer and the first passivation layer can be simultaneously manufactured by a tubular ALD device, and the tubular ALD device has a large processing capacity, which can be beneficial to improve the production efficiency of the solar cell; in addition, by setting the barrier layer between the first doping layer and the first passivation layer, or the barrier layer between the second doping layer and the second passivation layer, the barrier layer is configured to allow holes to pass through and inhibit electrons from passing through, thereby reducing the recombination of carriers in the first doping layer or the second doping layer, which is beneficial to improve the open circuit voltage of the solar cell, so that the solar cell maintains a high photoelectric conversion efficiency. In summary, the present application can improve the open circuit voltage of the solar cell while improving the production efficiency of the solar cell, so that the solar cell maintains a high photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of the structure of a solar cell in which a barrier layer is disposed between a second doping layer and a second passivation layer, provided in some embodiments of the present application.

[0018] FIG. 2 is another schematic structural diagram of the solar cell shown in FIG. 1 .

[0019] FIG3 is a schematic diagram of the structure of a solar cell in which a barrier layer is disposed between a first doping layer and a first passivation layer, provided in some embodiments of the present application.

[0020] FIG. 4 is another schematic structural diagram of the solar cell shown in FIG. 3 .

[0021] Description of reference numerals:

[0022] 1. Solar cells;

[0023] 110, substrate; 111, first surface; 112, second surface; 120, first doped layer; 130, first passivation layer; 140, tunneling layer; 150, second doped layer; 160, second passivation layer; 170, barrier layer; 180, first anti-reflection layer; 190, second anti-reflection layer; 210, first electrode; 220, second electrode. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0025] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0026] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0030] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electrical energy. As they are green and environmentally friendly products that do not cause environmental pollution, and solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.

[0031] At present, the mainstream batteries include tunnel oxide passivated contact batteries (TOPCon), interdigitated back contact batteries (IBC) and heterojunction batteries (HJT). The passivation contact structure composed of tunnel oxide layer and doped polysilicon layer in TOPCon (Tunnel Oxide passivated contact) batteries can effectively reduce the recombination rate between silicon wafer surface and metal contact, making TOPCon batteries one of the hot directions of high conversion efficiency silicon-based solar cells.

[0032] In the related art, a TOPCon cell is provided with a passivation layer only on its light-receiving surface. This can improve the open circuit voltage of the TOPCon cell and enable the TOPCon cell to maintain a relatively high photoelectric conversion efficiency, but it will reduce the production efficiency of the TOPCon cell.

[0033] Based on the above technical problems, the present application provides a solar cell, a photovoltaic module and a photovoltaic system to improve the open circuit voltage of the solar cell while improving the production efficiency of the solar cell, so that the solar cell maintains a high photoelectric conversion efficiency.

[0034] Figure 1 shows a schematic diagram of the structure of a solar cell in which a barrier layer is arranged between a second doping layer and a second passivation layer in some embodiments of the present application; Figure 3 shows a schematic diagram of the structure of a solar cell in which a barrier layer is arranged between a second doping layer and a second passivation layer in some embodiments of the present application.

[0035] In the first aspect, referring to FIG. 1 and FIG. 3 , an embodiment of the present application provides a solar cell 1, comprising a substrate 110, wherein a first doping layer 120 and a first passivation layer 130 are sequentially stacked on a first surface 111 of the substrate 110, a tunneling layer 140, a second doping layer 150 and a second passivation layer 160 are sequentially stacked on a second surface 112 of the substrate 110, and the first surface 111 and the second surface 112 are arranged opposite to each other; a barrier layer 170 is arranged between the first doping layer 120 and the first passivation layer 130, or, the barrier layer 170 is arranged between the second doping layer 150 and the second passivation layer 160, and the barrier layer 170 is configured to allow holes to pass through and inhibit electrons from passing through.

[0036] It should be noted that the first surface 111 may be the light-receiving surface of the solar cell 1 , and the second surface 112 may be the backlight surface of the solar cell 1 .

[0037] The substrate 110 may be a silicon wafer, and the silicon wafer may be an N-type silicon wafer or a P-type silicon wafer. When the silicon wafer may be an N-type silicon wafer, the first doping layer 120 may be a P-type doping layer, and the second doping layer 150 may be an N-type doped semiconductor layer, such as an N-type doped polysilicon layer; the barrier layer 170 may be disposed between the second doping layer 150 and the second passivation layer 160, whereby the barrier layer 170 may allow holes in the second doping layer 150 to pass through the barrier layer 170 to reach the second passivation layer 160, so that electrons are located in the second doping layer 150, thereby reducing the recombination of holes and electrons in the second doping layer 150, which is beneficial to improving the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a high photoelectric conversion efficiency. When the silicon wafer can be a P-type silicon wafer, the first doped layer 120 can be an N-type doped layer, and the second doped layer 150 can be a P-type doped semiconductor layer, such as a P-type doped polysilicon layer; the barrier layer 170 can be arranged between the first doped layer 120 and the first passivation layer 130, thereby, the barrier layer 170 can allow holes in the first doped layer 120 to pass through the barrier layer 170 to reach the first passivation layer 130, so that the electrons are located in the first doped layer 120, thereby reducing the recombination of holes and electrons in the first doped layer 120, which is beneficial to improve the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a high photoelectric conversion efficiency.

[0038] The material of the tunneling layer 140 may include silicon oxide. The thickness of the tunneling layer 140 is 1 nm to 2 nm; the thickness of the second doping layer 150 is 50 nm to 60 nm.

[0039] When the solar cell 1 is provided with a passivation layer only on the light-receiving surface, if a tubular ALD device is used for manufacturing, the backlight surface of the solar cell 1 will be circumferentially plated, which will affect the contact between the electrode and the doped polysilicon layer and reduce the photoelectric conversion efficiency of the solar cell 1. In the present application, a first doping layer 120 and a first passivation layer 130 are sequentially stacked on the first surface 111 of the substrate 110, and a tunneling layer 140, a second doping layer 150 and a second passivation layer 160 are sequentially stacked on the second surface 112 of the substrate 110, that is, the solar cell 1 has a double-sided passivation layer, so that the first passivation layer 130 and the first passivation layer 130 can be simultaneously manufactured by a tubular ALD device, which is convenient to manufacture and can effectively avoid the problem of circumferential plating; moreover, the tubular ALD device has a large processing capacity, which can be beneficial to improve the production efficiency of the solar cell 1; in addition, the thickness of the manufactured first passivation layer 130 and the second passivation layer 160 and the composition of the slurry when manufacturing the electrode can be adjusted to ensure the contact between the electrode and the doped polysilicon layer, so that the solar cell 1 maintains a high photoelectric conversion efficiency.

[0040] In summary, the solar cell 1 provided in the embodiment of the present application is configured such that a first doping layer 120 and a first passivation layer 130 are sequentially stacked on the first surface 111 of the substrate 110, and a tunneling layer 140, a second doping layer 150 and a second passivation layer 160 are sequentially stacked on the second surface 112 of the substrate 110. That is to say, the solar cell 1 has a double-sided passivation layer. Therefore, a tubular ALD device can be used to simultaneously manufacture the first passivation layer 130 and the first passivation layer 130, which is convenient to manufacture and can effectively avoid the problem of winding plating. Moreover, the tubular ALD device has a large processing capacity, which can help improve the production efficiency of the solar cell 1. In addition, by disposing the barrier layer 170 between the first doping layer 120 and the first passivation layer 130, or disposing the barrier layer 170 between the second doping layer 150 and the second passivation layer 160, the barrier layer 170 is configured to allow holes to pass through and inhibit the passage of electrons, thereby reducing the recombination of carriers in the first doping layer 120 or the second doping layer 150, which is beneficial to improve the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a high photoelectric conversion efficiency. In summary, the present application can improve the production efficiency of the solar cell 1 while increasing the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a high photoelectric conversion efficiency.

[0041] In some embodiments, the material of the barrier layer 170 includes at least one of molybdenum oxide and nickel oxide. Both molybdenum oxide and nickel oxide have a relatively high work function, and the conduction band offset of the contact interface with the substrate 110 is relatively large, and the valence band offset is relatively small, so they can be used as hole selective contact layers, thereby reducing the recombination of holes and electrons in the first doping layer 120 or the second doping layer 150, thereby effectively improving the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a relatively high photoelectric conversion efficiency.

[0042] In some embodiments, the thickness of the barrier layer 170 is 10 nm to 20 nm.

[0043] In some embodiments, the materials of the first passivation layer 130 and the second passivation layer 160 both include aluminum oxide.

[0044] For the N-type solar cell 1, aluminum oxide is formed on the side of the first doping layer 120 facing away from the substrate 110, and a natural passivation film is formed on the surface of the aluminum oxide. This passivation film adsorbs oxygen ions on the surface of the aluminum oxide, and forms a negatively charged aluminum oxide passivation film on the surface of the aluminum oxide, which can inhibit electrons from moving toward the first doping layer 120, thereby increasing the open circuit voltage of the solar cell 1; a barrier layer 170 and aluminum oxide are formed on the side of the second doping layer 150 facing away from the substrate 110, and the barrier layer 170 can prevent aluminum oxide from directly contacting the second doping layer 150. At the same time, the barrier layer 170 allows holes to pass through and inhibits electrons from passing through, thereby reducing the recombination of holes and electrons with the second doping layer 150, ensuring the passivation effect, and further enabling the solar cell 1 to maintain a high photoelectric conversion efficiency.

[0045] Corresponding to the P-type solar cell 1, a barrier layer 170 and aluminum oxide are formed on the side of the first doping layer 120 away from the substrate 110. The barrier layer 170 can prevent the aluminum oxide from directly contacting the first doping layer 120. At the same time, the barrier layer 170 allows holes to pass through and inhibits the passage of electrons, thereby reducing the recombination of holes and electrons in the first doping layer 120 and ensuring the passivation effect; aluminum oxide is formed on the side of the second doping layer 150 away from the substrate 110. Aluminum oxide can inhibit electrons from moving to the second doping layer 150, thereby increasing the open circuit voltage of the solar cell 1, and further enabling the solar cell 1 to maintain a relatively high photoelectric conversion efficiency.

[0046] In some embodiments, the thickness of the first passivation layer 130 and the second passivation layer 160 are both 4 nm to 5 nm. Thus, the passivation effect can be achieved and the contact between the electrode and the first doping layer 120 or the second doping layer 150 can be ensured, so that the solar cell 1 maintains a high photoelectric conversion efficiency.

[0047] As shown in FIG2 and FIG4, some embodiments further include a first anti-reflection layer 180 and a second anti-reflection layer 190, wherein the first anti-reflection layer 180 is disposed on the side of the first passivation layer 130 away from the substrate 110; and the second anti-reflection layer 190 is disposed on the side of the second passivation layer 160 away from the substrate 110. Thus, the light utilization rate of the solar cell 1 can be improved, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 1.

[0048] In some embodiments, the thickness of the first anti-reflection layer 180 and the second anti-reflection layer 190 are both 60 nm to 90 nm.

[0049] In some embodiments, the material of the first anti-reflection layer 180 and the second anti-reflection layer 190 includes at least one of aluminum oxide, silicon nitride, silicon oxide, gallium oxide, aluminum nitride, and silicon oxynitride.

[0050] As shown in Figures 2 and 4, some of the embodiments further include a first electrode 210 and a second electrode 220. The first electrode 210 is located on the side of the first passivation layer 130 away from the substrate 110 and is electrically connected to the first doping layer 120. The second electrode 220 is located on the side of the second passivation layer 160 away from the substrate 110, and the second electrode 220 is electrically connected to the second doping layer 150.

[0051] An embodiment of the second aspect of the present application provides a photovoltaic assembly, comprising the solar cell 1 according to the first aspect.

[0052] The photovoltaic module provided by the embodiment of the present application includes the solar cell 1 described in the first aspect. In the solar cell 1, a first doping layer 120 and a first passivation layer 130 are sequentially stacked on the first surface 111 of the substrate 110, and a tunneling layer 140, a second doping layer 150 and a second passivation layer 160 are sequentially stacked on the second surface 112 of the substrate 110. That is to say, the solar cell 1 has a double-sided passivation layer. Therefore, a tubular ALD device can be used to simultaneously manufacture the first passivation layer 130 and the first passivation layer 130, which is convenient to manufacture and can effectively avoid the problem of winding plating. Moreover, the tubular ALD device has a large processing capacity, which can be beneficial to improving the production efficiency of the solar cell 1, thereby improving the production efficiency of the photovoltaic module. In addition, by disposing the barrier layer 170 between the first doping layer 120 and the first passivation layer 130, or disposing the barrier layer 170 between the second doping layer 150 and the second passivation layer 160, the barrier layer 170 is configured to allow holes to pass through and inhibit the passage of electrons, thereby reducing the recombination of carriers in the first doping layer 120 or the second doping layer 150, which is beneficial to improving the open circuit voltage of the solar cell 1, so that the solar cell 1 maintains a high photoelectric conversion efficiency, thereby maintaining a high efficiency of the photovoltaic module.

[0053] The embodiment of the third aspect of the present application provides a photovoltaic system, comprising the photovoltaic assembly according to the first aspect, thereby improving the production efficiency of the photovoltaic system, so that the photovoltaic system maintains a high efficiency.

[0054] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A solar cell, characterized in that: include: A substrate, wherein a first doping layer and a first passivation layer are sequentially stacked on a first surface of the substrate, a tunneling layer, a second doping layer and a second passivation layer are sequentially stacked on a second surface of the substrate, and the first surface and the second surface are arranged opposite to each other; The barrier layer is disposed between the first doping layer and the first passivation layer, or between the second doping layer and the second passivation layer; the barrier layer is configured to allow holes to pass through and inhibit electrons from passing through.

2. The solar cell according to claim 1, characterized in that The material of the barrier layer includes at least one of molybdenum oxide and nickel oxide.

3. The solar cell according to claim 1, characterized in that The thickness of the barrier layer is 10 nm to 20 nm.

4. The solar cell according to claim 1, characterized in that The first passivation layer and the second passivation layer are both made of aluminum oxide.

5. The solar cell according to claim 1, characterized in that: The thickness of the first passivation layer and the second passivation layer are both 4 nm to 5 nm.

6. The solar cell according to claim 1, characterized in that The invention also includes a first anti-reflection layer and a second anti-reflection layer. The first anti-reflection layer is arranged on a side of the first passivation layer away from the substrate; and the second anti-reflection layer is arranged on a side of the second passivation layer away from the substrate.

7. The solar cell according to claim 6, characterized in that: The thickness of the first anti-reflection layer and the second anti-reflection layer are both 60nm to 90nm; and / or; The material of the first anti-reflection layer and the second anti-reflection layer includes at least one of aluminum oxide, silicon nitride, silicon oxide, gallium oxide, aluminum nitride, and silicon oxynitride.

8. The solar cell according to claim 1, characterized in that It also includes a first electrode and a second electrode, the first electrode is located on a side of the first passivation layer away from the substrate and is electrically connected to the first doped layer, the second electrode is located on a side of the second passivation layer away from the substrate and is electrically connected to the second doped layer.

9. A photovoltaic module, characterized in that: Comprising the solar cell according to any one of claims 1 to 8.

10. A photovoltaic system, characterized in that: Comprising the photovoltaic module according to claim 9.

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