Solar cell, solar module and solar system

Abstract

The utility model relates to the technical field of photovoltaic power generation, and discloses a solar cell. The solar cell comprises a silicon substrate, a first composite layer, a second composite layer, a first electrode and a second electrode, the first composite layer comprises a plurality of first dielectric layers and a plurality of boron-doped layers, and the first dielectric layers are arranged on the surfaces, close to the silicon substrate, of the boron-doped layers; the second composite layer comprises a plurality of second dielectric layers and a plurality of phosphorus-doped layers, and the second dielectric layers are arranged on the surfaces, close to the silicon substrate, of the phosphorus-doped layers; the first electrode is connected with the first composite layer; the second electrode is connected with the second composite layer; wherein the first dielectric layer and the second dielectric layer are used for preventing boron and phosphorus in the boron doping and phosphorus doping layer from entering the silicon substrate. The first dielectric layer and the second dielectric layer are arranged to prevent boron and phosphorus from entering the silicon substrate, recombination is effectively reduced, the conversion efficiency of the cell and the overall performance of the cell are guaranteed, the polycrystalline silicon layer keeps high-concentration phosphorus or boron doping, the internal resistance of the cell is reduced, and the conductivity of the cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation, in particular to a solar cell, a solar energy component and a solar energy system. Background Art

[0002] The main principle of photovoltaic power generation is the photoelectric effect of semiconductors. The photoelectric effect is an important and magical phenomenon in physics. Under the irradiation of electromagnetic waves above a certain frequency, the electrons inside certain substances absorb energy and escape to form current, which is photoelectricity. Solar cells are a type of photoelectric semiconductor sheet that uses sunlight to directly generate electricity. They are also called "solar chips" or "photovoltaic cells". As long as they are illuminated by light that meets certain illumination conditions, they can instantly output voltage and generate current in the presence of a circuit.

[0003] Existing solar cells are equipped with a polysilicon layer, which is used to electrically connect to the electrodes. In order to achieve lower resistance and better conductivity, high concentrations of phosphorus or boron are doped into the polysilicon layer. However, doping with high concentrations of phosphorus or boron will lead to a large amount of recombination, thereby reducing the conversion efficiency of the battery and affecting the battery performance. Utility Model Content

[0004] The technical problems to be solved by the utility model are:

[0005] Doping the polysilicon layer with high concentrations of phosphorus or boron will lead to a large amount of recombination, thereby reducing the conversion efficiency and affecting the battery performance.

[0006] In order to solve the above technical problems, the utility model provides a solar cell, comprising:

[0007] Silicon substrate;

[0008] A first composite layer is arranged on one side of the silicon substrate; the first composite layer comprises a plurality of first dielectric layers and a plurality of boron-doped layers, the first dielectric layer is connected to the boron-doped layers, and the first dielectric layer is arranged on one side of the boron-doped layers close to the silicon substrate;

[0009] A second composite layer, wherein the second composite layer and the first composite layer are arranged on the same surface of the silicon substrate; the second composite layer comprises a plurality of second dielectric layers and a plurality of phosphorus-doped layers, the second dielectric layer is connected to the phosphorus-doped layers, and the second dielectric layer is arranged on a surface of the phosphorus-doped layers close to the silicon substrate;

[0010] A first electrode connected to the first composite layer; and

[0011] a second electrode connected to the second composite layer;

[0012] The first dielectric layer is used to prevent boron in the boron-doped layer from entering the silicon substrate, and the second dielectric layer is used to prevent phosphorus in the phosphorus-doped layer from entering the silicon substrate.

[0013] In one embodiment, the number of the first dielectric layers and the number of the boron-doped layers are the same, and a plurality of the first dielectric layers are spaced apart by a plurality of the boron-doped layers and are stacked.

[0014] In one embodiment, the silicon substrate is a P-type silicon substrate or an N-type silicon substrate.

[0015] In one embodiment, in a direction from the silicon substrate toward the first electrode, the boron concentration in the boron doped layer increases layer by layer.

[0016] In one embodiment, the number of the second dielectric layers is the same as the number of the phosphorus-doped layers, and a plurality of the second dielectric layers are spaced apart by a plurality of the phosphorus-doped layers and are stacked.

[0017] In one of the embodiments, in a direction from the silicon substrate toward the second electrode, the phosphorus concentration in the phosphorus-doped layer increases layer by layer.

[0018] In one embodiment, the first electrode and the second electrode are located on the same surface of the silicon substrate.

[0019] In one embodiment, the solar cell further comprises a spacer layer; the spacer layer is disposed between the first composite layer and the second composite layer;

[0020] The solar cell also includes a first passivation layer and a second passivation layer; the first passivation layer is connected to the silicon substrate, and the first passivation layer is arranged on a side of the silicon substrate away from the first composite layer; the second passivation layer is arranged on a side of the first composite layer and the second composite layer away from the silicon substrate.

[0021] A solar panel assembly comprises a welding strip, an adhesive film, a glass panel, a frame, and at least two of the above-mentioned solar cells; the solar cells are arranged at intervals, the welding strip electrically connects the solar cells, the glass panel covers the outside of the solar cell, the adhesive film is arranged between the glass panel and the solar cell, and the frame is extended along the periphery of the glass panel.

[0022] A solar energy system comprises the above-mentioned solar energy component and an inverter; the inverter is electrically connected to the solar energy component.

[0023] Compared with the prior art, the above solar cell has the following beneficial effects:

[0024] By setting multiple layers of first dielectric layers to block the boron in the boron-doped layer from entering the silicon substrate, and setting multiple layers of second dielectric layers to block the phosphorus in the phosphorus-doped layer from entering the silicon substrate, it is avoided that the doping concentration increases after boron and phosphorus enter the silicon substrate, thereby causing a large amount of recombination to occur, thereby improving the conversion efficiency and overall performance of the battery. At the same time, a high concentration of phosphorus or boron doping can be maintained in polysilicon, effectively reducing the internal resistance of the battery and improving the conductivity of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a solar cell according to one embodiment of the utility model.

[0026] The meanings of the numbers in the accompanying drawings are:

[0027] 100. Solar cells;

[0028] 10. Silicon substrate;

[0029] 20. first composite layer; 21. first dielectric layer; 22. boron doped layer;

[0030] 30. second composite layer; 31. second dielectric layer; 32. phosphorus-doped layer;

[0031] 40. a first electrode;

[0032] 50. a second electrode;

[0033] 60. Spacer layer;

[0034] 70. A first passivation layer;

[0035] 80. Second passivation layer. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model 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 utility model. However, the utility model 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 utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0037] In the description of the present invention, it should be understood that 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral 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 the present invention can be understood according to specific circumstances.

[0040] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a 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. A first feature being "below", "below" or "below" a 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.

[0041] It should be noted that when 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. When 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. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0042] See also Figure 1 , is a solar cell 100 according to an embodiment of the present utility model, comprising a silicon substrate 10, a first composite layer 20, a second composite layer 30, a first electrode 40 and a second electrode 50. The first composite layer 20 is arranged on one side of the silicon substrate 10; the first composite layer 20 comprises a plurality of first dielectric layers 21 and a plurality of boron-doped layers 22, the first dielectric layers 21 are connected to the boron-doped layers 22, and the first dielectric layers 21 are arranged on one side of the boron-doped layers 22 close to the silicon substrate 10. The second composite layer 30 and the first composite layer 20 are arranged on the same side of the silicon substrate 10; the second composite layer 30 comprises a plurality of second dielectric layers 31 and a plurality of phosphorus-doped layers 32, the second dielectric layers 31 are connected to the phosphorus-doped layers 32, and the second dielectric layers 31 are arranged on one side of the phosphorus-doped layers 32 close to the silicon substrate 10. The first electrode 40 is connected to the first composite layer 20. The second electrode 50 is connected to the second composite layer 30. Among them, the first dielectric layer 21 is used to block the boron in the boron-doped layer 22 from entering the silicon substrate 10, and the second dielectric layer 31 is used to block the phosphorus in the phosphorus-doped layer 32 from entering the silicon substrate 10, thereby preventing phosphorus or boron from entering the silicon substrate 10 and recombining, thereby ensuring the photoelectric conversion efficiency of the battery and improving the performance of the battery; and because the disadvantages of high-concentration doping of phosphorus or boron are eliminated, the boron concentration and phosphorus concentration in the boron-doped layer 22 and the phosphorus-doped layer 32 can be high concentrations, which greatly improves the conductivity of the boron-doped layer 22 and the phosphorus-doped layer 32, thereby improving the overall comprehensive performance of the solar cell 100.

[0043] Further, the silicon substrate 10 is an N-type silicon substrate 10 or a P-type silicon substrate 10. Since silicon atoms have four outer electrons, if atoms with five outer electrons, such as phosphorus atoms, are doped into silicon, it becomes an N-type silicon substrate 10; if atoms with three outer electrons, such as boron atoms, are doped into silicon, it becomes a P-type silicon substrate 10. It can be understood that whether the silicon substrate 10 is an N-type silicon substrate 10 or a P-type silicon substrate 10 is not limited here, and it is sufficient to ensure that the solar cell 100 can perform photoelectric conversion normally.

[0044] Further, the number of the boron-doped layers 22 in the first composite layer 20 is multiple, the number of the first dielectric layer 21 and the boron-doped layer 22 is the same, and the multiple first dielectric layers 21 are spaced and stacked by the multiple boron-doped layers 22. The boron-doped layers 22 are spaced and arranged in parallel, and the first dielectric layers 21 are arranged on the side of each boron-doped layer 22 close to the silicon substrate 10, that is, the boron-doped layers 22 and the first dielectric layers 21 are arranged alternately on the side of the silicon substrate 10. In each first dielectric layer 21, the first dielectric layer 21 closest to the silicon substrate 10 is connected to the silicon substrate 10; in each boron-doped layer 22, the boron-doped layer 22 farthest from the silicon substrate 10 is connected to the first electrode 40. The arrangement structure of the multi-layered first dielectric layer 21 and the boron-doped layer 22 can effectively prevent boron from entering the silicon substrate 10.

[0045] Further, in the direction from the silicon substrate 10 to the first electrode 40, the boron concentration in the boron doped layer 22 increases layer by layer. The increase in the boron concentration in the boron doped layer 22 can effectively improve the conductivity of the boron doped layer 22, but a high concentration of boron will lead to increased recombination, and setting the boron concentration in the boron doped layer 22 to be lower the closer to the silicon substrate 10, the recombination can be effectively reduced, and the photoelectric conversion efficiency of the boron doped layer 22 can be improved, and setting the boron concentration in the boron doped layer 22 to be higher the closer to the first electrode 40, the conductivity of the boron doped layer 22 can be effectively improved, thereby improving the overall conductivity of the solar cell 100. Changing the boron concentration in the boron doped layer 22 in a step-like manner layer by layer can effectively improve the photoelectric conversion efficiency of the solar cell 100, while improving the overall conductivity of the solar cell 100.

[0046] Further, the structure of the second composite layer 30 corresponds to the structure of the first composite layer 20. The number of the phosphorus-doped layers 32 in the second composite layer 30 is multiple, the number of the second dielectric layer 31 and the phosphorus-doped layer 32 is the same, and the multiple second dielectric layers 31 are spaced and stacked by multiple phosphorus-doped layers 32. Each phosphorus-doped layer 32 is spaced in parallel, and the second dielectric layer 31 is arranged on a side of each phosphorus-doped layer 32 close to the silicon substrate 10, that is, the phosphorus-doped layer 32 and the second dielectric layer 31 are alternately arranged on a side of the silicon substrate 10. In each second dielectric layer 31, the second dielectric layer 31 closest to the silicon substrate 10 is connected to the silicon substrate 10; in each phosphorus-doped layer 32, the phosphorus-doped layer 32 farthest from the silicon substrate 10 is connected to the second electrode 50. The arrangement structure of the multi-layer spaced second dielectric layer 31 and the phosphorus-doped layer 32 can effectively improve the stability of blocking phosphorus from entering the silicon substrate 10. In this embodiment, the phosphorus concentration in the phosphorus-doped layer 32 increases layer by layer in the direction from the silicon substrate 10 to the second electrode 50. The increase in the phosphorus concentration in the phosphorus-doped layer 32 can effectively improve the conductivity of the phosphorus-doped layer 32, but a high concentration of phosphorus will lead to stronger recombination, and the phosphorus concentration in the phosphorus-doped layer 32 is set to be lower the closer to the silicon substrate 10, which can effectively reduce the recombination and improve the photoelectric conversion efficiency of the phosphorus-doped layer 32, and the phosphorus concentration in the phosphorus-doped layer 32 is set to be higher the closer to the second electrode 50, which can effectively improve the conductivity of the phosphorus-doped layer 32, thereby improving the overall performance of the solar cell 100. The phosphorus concentration in the phosphorus-doped layer 32 is changed layer by layer in a step-like manner, which can effectively improve the photoelectric conversion efficiency of the solar cell 100.

[0047] Further, the first dielectric layer 21 is a silicon dioxide layer or a silicon oxynitride layer, and the second dielectric layer 31 is a silicon dioxide layer or a silicon oxynitride layer. Both the silicon dioxide layer and the silicon oxynitride layer can effectively block boron and phosphorus, thereby preventing the boron and phosphorus in the boron-doped layer 22 and the phosphorus-doped layer 32 from being doped into the silicon substrate 10, and avoiding the occurrence of recombination in the silicon substrate 10. At the same time, the first dielectric layer 21 is arranged between each layer of the boron-doped layer 22, and the second dielectric layer 31 is arranged between each layer of the phosphorus-doped layer 32, which effectively ensures that the boron and phosphorus concentrations in each layer of the boron-doped layer 22 and the phosphorus-doped layer 32 change step by step, thereby improving the photoelectric conversion efficiency of the boron-doped layer 22 and the phosphorus-doped layer 32.

[0048] Further, the number of the boron-doped layers 22 is two to five, and the corresponding number of the first dielectric layers 21 is the same as the boron-doped layers 22, which is two to five. The number of the phosphorus-doped layers 32 may be different from the number of the boron-doped layers 22, the number of the phosphorus-doped layers 32 is two to five, and the number of the second dielectric layers 31 and the phosphorus-doped layers 32 is the same as two to five. In this embodiment, the number of the boron-doped layers 22 and the phosphorus-doped layers 32 is the same as three.

[0049] Furthermore, the first electrode 40 is connected to the boron-doped layer 22, and the second electrode 50 is connected to the phosphorus-doped layer 32. The first electrode 40 and the second electrode 50 are connected to an external circuit and connected to each other, so that sunlight can be converted into electric current. In this embodiment, the first electrode 40 is a positive electrode, and the second electrode 50 is a negative electrode.

[0050] Furthermore, the first electrode 40 and the second electrode 50 are located on the same surface of the silicon substrate 10, so that the side of the silicon substrate 10 provided with the first electrode 40 and the second electrode 50 is used as the back side, and the side of the silicon substrate 10 away from the first electrode 40 and the second electrode 50 is used as the front side, and the front side of the silicon substrate 10 is facing the sunlight, so that the electrodes can be effectively avoided from blocking the sunlight, thereby increasing the area of ​​the silicon substrate 10 irradiated by sunlight, and improving the photoelectric conversion efficiency of the solar cell 100.

[0051] Furthermore, the solar cell 100 further includes a spacer layer 60. The spacer layer 60 is an insulating layer, and is disposed between the first composite layer 20 and the second composite layer 30, thereby avoiding a short circuit between the first composite layer 20 and the second composite layer 30 during the photoelectric conversion process, thereby improving the reliability of the solar cell 100.

[0052] Furthermore, the solar cell 100 further includes a first passivation layer 70 and a second passivation layer 80. The first passivation layer 70 is connected to the silicon substrate 10, and the first passivation layer 70 is arranged on a side of the silicon substrate 10 away from the first composite layer 20; the second passivation layer 80 is arranged on a side of the first composite layer 20 and the second composite layer 30 away from the silicon substrate 10. In this embodiment, the first passivation layer 70 and the second passivation layer 80 are oxide layers or nitride layers, and the first passivation layer 70 and the second passivation layer 80 are covered on the outside of the solar cell 100, which effectively prevents the inside of the solar cell 100 from being oxidized or corroded, thereby improving the use stability and service life of the solar cell 100.

[0053] The utility model also provides a solar module (not shown), comprising a welding strip, an adhesive film, a glass panel, a frame, and at least two of the above-mentioned solar cells 100. The solar cells 100 are arranged at intervals, and the solar cells 100 are used to convert light energy into electrical energy. The welding strip electrically connects the solar cells 100, and the welding strip is used to collect current and conduct electricity. The solar cells 100 are connected in series and parallel through the welding strip to achieve a certain rated output power and voltage. The glass panel covers the outer side of the solar cell 100, and the glass panel is used to encapsulate each pair of solar cells 100. The glass panel is a light-transmitting member to ensure that sunlight enters the solar cell 100 through the glass panel. The adhesive film is arranged between the glass panel and the solar cell 100, and the adhesive film is used to bond the glass panel to the solar cell 100 to play a role of encapsulation protection, and protect the solar cell 100 from interference from the external environment. The frame is extended along the periphery of the glass panel, and the frame fixes the solar cell 100, the adhesive film and the glass panel, and seals and protects the periphery of the solar module, which is convenient for the installation and transportation of the solar module.

[0054] The utility model also provides a solar energy system (not shown), including the above-mentioned solar energy module and inverter. The solar energy module is used to convert sunlight into electrical energy and transmit it to the outside world at a certain rated voltage. The solar energy module transmits direct current to the outside world. The inverter is used to convert the direct current output by the solar energy module into alternating current, thereby meeting the use demand of external electrical devices for alternating current.

[0055] In summary, the embodiment of the utility model provides a solar cell 100, which blocks the boron in the boron-doped layer 22 from entering the silicon substrate 10 by setting a multi-layer first dielectric layer 21, and blocks the phosphorus in the phosphorus-doped layer 32 from entering the silicon substrate 10 by setting a multi-layer second dielectric layer 31, thereby preventing boron and phosphorus from entering the silicon substrate, resulting in an increase in doping concentration and causing a large amount of recombination, thereby improving the conversion efficiency of the battery and the overall performance of the battery, and at the same time maintaining a high concentration of phosphorus or boron doping in polycrystalline silicon, effectively reducing the internal resistance of the battery and improving the conductivity of the battery.

[0056] 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.

[0057] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A solar cell, characterized in that: include: Silicon substrate; A first composite layer is arranged on one side of the silicon substrate; the first composite layer comprises a plurality of first dielectric layers and a plurality of boron-doped layers, the first dielectric layer is connected to the boron-doped layers, and the first dielectric layer is arranged on one side of the boron-doped layers close to the silicon substrate; A second composite layer, wherein the second composite layer and the first composite layer are arranged on the same surface of the silicon substrate; the second composite layer comprises a plurality of second dielectric layers and a plurality of phosphorus-doped layers, the second dielectric layer is connected to the phosphorus-doped layers, and the second dielectric layer is arranged on a surface of the phosphorus-doped layers close to the silicon substrate; a first electrode connected to the first composite layer; and a second electrode connected to the second composite layer; The first dielectric layer is used to prevent boron in the boron-doped layer from entering the silicon substrate, and the second dielectric layer is used to prevent phosphorus in the phosphorus-doped layer from entering the silicon substrate.

2. The solar cell according to claim 1, characterized in that: The number of the first dielectric layers is the same as that of the boron-doped layers, and a plurality of the first dielectric layers are spaced apart by a plurality of the boron-doped layers and are stacked.

3. The solar cell according to claim 2, characterized in that: The silicon substrate is a P-type silicon substrate or an N-type silicon substrate.

4. The solar cell according to claim 1, characterized in that The number of the second dielectric layers is the same as the number of the phosphorus-doped layers, and a plurality of the second dielectric layers are spaced apart by a plurality of the phosphorus-doped layers and are stacked.

5. The solar cell according to claim 1, characterized in that: The first electrode and the second electrode are located on the same surface of the silicon substrate.

6. The solar cell according to claim 5, characterized in that: The solar cell further comprises a spacer layer; the spacer layer is arranged between the first composite layer and the second composite layer; The solar cell also includes a first passivation layer and a second passivation layer; the first passivation layer is connected to the silicon substrate, and the first passivation layer is arranged on a side of the silicon substrate away from the first composite layer; the second passivation layer is arranged on a side of the first composite layer and the second composite layer away from the silicon substrate.

7. A solar panel, characterized in that: It includes a soldering ribbon, an adhesive film, a glass panel, a frame, and at least two solar cells according to any one of claims 1 to 6; the solar cells are arranged at intervals, the soldering ribbon electrically connects the solar cells, the glass panel covers the outside of the solar cell, the adhesive film is arranged between the glass panel and the solar cell, and the frame is extended along the periphery of the glass panel.

8. A solar energy system, characterized in that: It comprises the solar energy component and the inverter as claimed in claim 7; the inverter is electrically connected to the solar energy component.

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