Heterojunction solar cell and photovoltaic module
By providing conductive channels on the first fine gate side and/or top surface of the heterojunction solar cell, electrical connection with the conductive parts is achieved, and the complexity problem of removing passivation and anti-reverse layers in the prior art is solved, the process is simplified and production adaptability is improved.
Patent Information
- Application Number
- CN202420775015.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-15
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-04-15
AI Technical Summary
Existing heterojunction solar cells need to add additional processes to remove passivation and anti-reverse layers before or after preparing metal electrodes, which increases operational difficulty and process complexity.
By providing conductive channels on the sides and/or top surfaces of the first fine gate, an electrical connection between the first fine gate and the conductive member is achieved, and the need to remove the passivation and anti-reverse layer is avoided.
The preparation process of heterojunction solar cells is simplified, the photoelectric conversion performance is ensured, and it is suitable for large-scale production.
Smart Images
Figure CN222764227U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solar cell manufacturing, in particular to a heterojunction solar cell and a photovoltaic module. Background Art
[0002] Heterojunction solar cells can combine the advantages of single-crystal silicon solar cells and amorphous silicon solar cells. Under the low-temperature preparation process, they have the characteristics of double-sided power generation and high conversion efficiency. In the prior art, an anti-reflection layer is generally provided to increase the transmittance of photogenerated carriers in the conductive film layer on the front side of the heterojunction solar cell. However, since the anti-reflection layer is made of an insulating material, whether the anti-reflection layer is prepared before or after the metal electrode is prepared, an additional process is required to remove the anti-reflection layer in the area corresponding to the electrode fine grid so that the electrode fine grid is electrically connected to the conductive film layer. At the same time, the existing process usually uses a patterned mold opening tool for etching, which also increases the difficulty of operation for controlling the etching accuracy. Utility Model Content
[0003] In view of this, the embodiments of the utility model provide a heterojunction solar cell and a photovoltaic module, in which a passivation anti-reflection layer is provided on the top surface of the first fine grid, and the electrical connection between the first fine grid and the conductive member is realized by using the conductive channel on the side and / or top surface of the first fine grid. Not only the photoelectric conversion performance of the heterojunction solar cell is guaranteed, but also the passivation anti-reflection layer on the top of the first fine grid does not need to be removed by an additional process, and the heterojunction solar cell formed has a simple structure and is suitable for large-scale production.
[0004] In order to solve the above technical problems, the utility model provides the following technical solutions:
[0005] In a first aspect, the utility model provides a heterojunction solar cell, comprising: a silicon substrate, a first conductive film layer arranged on one side in the thickness direction of the silicon substrate, a first fine grid arranged on the first conductive film layer, and a passivation anti-reflection layer arranged on an area not covered by the first fine grid on the first conductive film layer and on a top surface of the first fine grid; wherein the side surface and / or top surface of the first fine grid is electrically connected to a conductive member via a conductive channel.
[0006] Optionally, the heterojunction solar cell further comprises: a conductive channel located on the top surface of the first fine grid and distributed in the passivation anti-reflection layer; the top surface of the first fine grid is electrically connected to the conductive member through the conductive channel.
[0007] Optionally, an angle between a side surface of the first fine grid and the first conductive film layer toward an inner side of the first fine grid is greater than or equal to 80° and less than or equal to 95°.
[0008] Optionally, the heterojunction solar cell further includes: a first intrinsic crystalline silicon layer and a first doping layer doped with a first type of element, which are sequentially arranged between the silicon substrate and the first conductive film layer.
[0009] Optionally, the conductive member is a first main grid of the heterojunction solar cell.
[0010] Optionally, a second intrinsic crystalline silicon layer, a second doped layer doped with a second type element, and a second conductive film layer are sequentially arranged on the other side of the silicon substrate in the thickness direction; a second fine gate is arranged on the second conductive film layer, and a second main gate connected to the second fine gate.
[0011] Optionally, the thickness of the first conductive film layer is smaller than the thickness of the second conductive film layer.
[0012] Optionally, the thickness of the first intrinsic crystalline silicon layer and / or the second intrinsic crystalline silicon layer is 1-50 nm; and / or the thickness of the first fine gate 100 is 5-30 μm.
[0013] In a second aspect, the utility model provides a photovoltaic module, comprising: the above-mentioned heterojunction solar cell.
[0014] The technical solution of the first aspect of the utility model has the following advantages or beneficial effects: when a passivation anti-reflection layer is provided on the top surface of the first fine grid, by making the first fine grid on the side and / or top surface of the first fine grid electrically connected to the conductive member, not only the photoelectric conversion performance of the heterojunction solar cell is guaranteed, but also the passivation anti-reflection layer on the top of the first fine grid does not need to be removed by an additional process, and the heterojunction solar cell formed has a simple structure and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation on the present invention.
[0016] Figure 1 It is a schematic structural diagram of a heterojunction solar cell according to an embodiment of the utility model;
[0017] Figure 2 It is a schematic diagram of the partial structure of a heterojunction solar cell according to an embodiment of the utility model;
[0018] Figure 3 It is a top view of a heterojunction solar cell provided according to an embodiment of the utility model.
[0019] The reference numerals are as follows:
[0020] 1-silicon substrate; 2-first conductive film layer; 3-passivation anti-reflection layer; 4-conductive member; 5-conductive channel; 6-first intrinsic crystalline silicon layer; 7-first doped layer; 8-second intrinsic crystalline silicon layer; 9-second doped layer; 10-second conductive film layer; 100-first fine gate; 200-second fine gate. DETAILED DESCRIPTION
[0021] A solar cell is a photoelectric semiconductor wafer that uses sunlight to generate electricity directly. It is also called a "solar chip" or "photovoltaic cell". As long as it is illuminated by light that meets certain illumination conditions, it can instantly output voltage and generate current in the presence of a circuit. In physics, it is called solar photovoltaic (PV), or photovoltaic for short. In order to conveniently and clearly describe the method for preparing a solar cell and the solar cell of the utility model, the following exemplary embodiments of the utility model are described in conjunction with the accompanying drawings, including various details of the embodiments of the utility model to facilitate understanding, and they should be considered to be merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the utility model. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.
[0022] In recent years, for heterojunction solar cells, setting a passivation anti-reflection layer on the conductive film layer on the front of the cell is an effective means to improve the performance of heterojunction solar cells, that is, by setting a passivation anti-reflection layer, the light absorption of the conductive film layer can be increased, the transmittance of the carriers can be increased, and the silicon wafer can be protected and passivated at the same time, which can increase the electro-generated voltage and effectively improve the performance of photovoltaic cells. However, due to the insulating properties of the passivation anti-reflection layer, in order to ensure the electrical connection between the fine grid and the conductive part, it is necessary to remove the passivation anti-reflection layer of the metal area corresponding to the fine grid. For heterojunction cells, if the traditional high-temperature slurry is used for high-temperature sintering, the conductive film layer will be damaged, so it can only be prepared at a low temperature. Therefore, in the prior art, the passivation anti-reflection layer corresponding to the metal area where the fine grid is set is usually etched by patterned film formation, that is, an etching process is added before the fine grid is prepared to obtain a solar cell with only the passivation anti-reflection layer of the non-metallic area retained.
[0023] In one embodiment of the present invention, Figure 1As shown, this embodiment provides a heterojunction solar cell, which comprises: a silicon substrate 1, a first conductive film layer 2 arranged on one side in the thickness direction of the silicon substrate 1, a first fine grid 100 arranged on the first conductive film layer 2, and a passivation anti-reflection layer 3 arranged on the area not covered by the first fine grid 100 on the first conductive film layer 2 and on the top surface of the first fine grid 100; wherein the side surface and / or the top surface of the first fine grid 100 is electrically connected to the conductive member 4.
[0024] Compared with the prior art, the heterojunction solar cell provided by the present invention retains the passivation anti-reflection layer 3 in the area corresponding to the first fine grid 100, and realizes electrical connection between the conductive member 4 and the first fine grid 100 through different parts of the first fine grid 100 to form a complete series structure.
[0025] In the present invention, since the structures of the first fine grid 100 formed by different preparation processes are different, the connection positions between the conductive member 4 and the first fine grid 100 are also different. The connection positions are specifically described below when the first fine grid 100 is prepared by different preparation methods:
[0026] (1) The first fine grid 100 is formed by low temperature slurry printing
[0027] In an optional embodiment, the heterojunction solar cell further includes: a conductive channel 5 located on the top surface of the first fine grid 100 and distributed in the passivation anti-reflection layer 3; the top surface of the first fine grid 100 is electrically connected to the conductive member 4 through the conductive channel 5. It should be noted that due to the large particle size of the low-temperature slurry particles and the large surface roughness of the printed linear shape, the passivation anti-reflection layer cannot be completely covered, so the conductive channel 5 will be retained.
[0028] Since the process of preparing the passivation anti-reflection layer 3 is usually after preparing the first fine grid 100, there are two situations. One is that the passivation anti-reflection layer 3 only exists on the top surface of the first fine grid 100, that is, the side of the first fine grid 100 is not covered. In this case, for the first fine grid 100 formed by low-temperature slurry printing, the side of the first fine grid 100 can also be connected to the conductive member 4, that is, the top surface and side of the first fine grid 100 are connected to the conductive member 4. The other is that the passivation anti-reflection layer 3 not only exists on the top surface of the first fine grid 100 due to winding plating or other preparation processes, but also forms a thinner passivation anti-reflection layer 3 on the side. In this case, the side of the first fine grid 100 can be cleaned with hydrofluoric acid to ensure that the side of the first fine grid 100 can be connected to the conductive member 4.
[0029] (2) The first fine grid 100 is prepared by a special metallization method
[0030] In an optional embodiment, the angle between the side of the first fine grid 100 and the first conductive film layer 2 toward the inside of the first fine grid 100 is greater than or equal to 80° and less than or equal to 95°. Since the particles inside the first fine grid 100 obtained by the metallization method are relatively small and the formed structure is relatively dense, they cannot be dispersed into the passivation anti-reflection layer 3 to form a conductive channel 5. Therefore, it is necessary to form a first fine grid 100 of a specific shape to ensure that when the passivation anti-reflection layer 3 is prepared, the side of the first fine grid 100 is not wrapped, that is, to ensure that the side of the first fine grid 100 is connected to the conductive member 4, thereby achieving electrical connection between the first fine grid 100 and the conductive member 4. Among them, the special metallization method can include at least one of the following: electroplating, steel plate, transfer printing.
[0031] In a further optional embodiment, if Figure 2 As shown, for the left and right sides of the first fine grid 100, it is necessary to ensure that the angle between the first fine grid 100 and the first conductive film layer 2 toward the inside of the first fine grid 100 is greater than or equal to 80° and less than or equal to 95°, that is, to ensure that the side faces are relatively vertical to avoid forming the passivation anti-reflection layer 3. Specifically, α represents the angle between the left side of the first fine grid 100 and the first conductive film layer 2, and β represents the angle between the right side of the first fine grid 100 and the first conductive film layer 2, wherein 80°≤α≤95° and 80°≤β≤95°, for example, the angles of α and β can be 80°, 82°, 85°, 87°, 90°, 92° or 95°, etc.
[0032] It should be noted that different preparation processes of the passivation anti-reflection layer 3 will also affect the structure of the formed passivation anti-reflection layer 3. Therefore, in an optional embodiment, the passivation anti-reflection layer 3 is prepared by methods such as sputtering and reactive plasma deposition (RPD). The utility model can ensure that the passivation anti-reflection layer 3 only covers the top surface of the first conductive film layer 2 by designing the edge angle of the first fine grid 100 and combining the film forming effects of sputtering and RPD methods, thereby ensuring that the side of the first fine grid 100 is conductive to the conductive member 4.
[0033] (3) The first fine grid 100 is formed by superimposing a low-temperature slurry using a special metallization method.
[0034] It is understandable that, due to the material properties of the low-temperature paste itself, when the first fine grid 100 is formed by stacking the low-temperature paste in a special metallization manner, a conductive channel 5 can also be formed on the top surface of the first fine grid 100 .
[0035] In a further optional embodiment, by limiting the angle between the side surface of the first fine gate 100 and the first conductive film layer 2 to be greater than or equal to 80° and less than or equal to 95°, it can be ensured that the passivation anti-reflection layer 3 is not formed on the side surface of the first fine gate 100, that is, in this case, the purpose of electrical conduction can be achieved between the top surface and the side surface of the first fine gate 100 and the conductive element 4.
[0036] Through the three different preparation methods (1)-(3) mentioned above, different settings can be made for the first fine gate 100 in different forms to ensure that a conductive channel is formed between the first fine gate 100 and the conductive member 4, thereby achieving electrical connection. There is no need to add an additional etching process to remove the passivation anti-reflection layer 3 on the top of the first fine gate 100, thereby simplifying the preparation process.
[0037] It is understandable that the conductive member 4 can be a main grid or a welding strip. For example, for a heterojunction solar cell, the conductive member 4 is the first main grid of the heterojunction solar cell. For a cell without a main grid, the conductive member 4 is used to connect the welding strip of the fine grid. Specifically, the connection relationship between the first main grid and the first fine grid 100 is as follows: Figure 3 As shown, Figure 3 A top view of a heterojunction solar cell.
[0038] In an optional embodiment, the thickness of the first fine grid 100 is 5-30 μm. Specifically, the first fine grid 100 formed by low-temperature slurry printing has a thickness of 7-15 μm, such as 7 μm, 9 μm, 11 μm, 13 μm, 15 μm, etc. The first fine grid 100 prepared by metallization has a thickness of 20-25 μm, such as 20 μm, 22 μm, 24 μm, 25 μm, etc. It can be understood that when the first fine grid 100 only has the second conductive channel 6 on the side, in order to ensure the conductive efficiency, it is necessary to ensure the thickness of the first fine grid 100 to ensure that a wider conductive channel is formed to meet the current demand.
[0039] In an optional embodiment of the present invention, the heterojunction solar cell provided is as follows Figure 1 As shown, it also includes: a first intrinsic crystalline silicon layer 6 and a first doped layer 7 doped with a first type element, which are sequentially arranged between the silicon substrate 1 and the first conductive film layer 2. The first intrinsic crystalline silicon layer 6 includes one or more of the following materials with the same or different properties: microcrystalline silicon, nano silicon, amorphous silicon, silicon oxide, and silicon carbide.
[0040] In an optional embodiment of the utility model, the heterojunction solar cell further includes: a second intrinsic crystalline silicon layer 8, a second doping layer 9 doped with a second type element, and a second conductive film layer 10 sequentially arranged on the other side of the silicon substrate 1 in the thickness direction; a second fine gate 200 arranged on the second conductive film layer 10, and a second main gate connected to the second fine gate 200. The second intrinsic crystalline silicon layer 8 includes one or more of the following materials with the same or different properties: microcrystalline silicon, nano silicon, amorphous silicon, silicon oxide, and silicon carbide.
[0041] Regarding the positions of the first fine gate 100 and the second fine gate 200, in an optional embodiment, the first fine gate 100 can be arranged vertically corresponding to the second fine gate 200. In addition, the thickness of the first intrinsic crystalline silicon layer 6 and / or the second intrinsic crystalline silicon layer 8 is 1 to 50 nm, for example, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm or 50 nm.
[0042] In the present invention, since the passivation anti-reflection layer 3 is provided on the first conductive film layer 2, the transmittance of the carriers in the first conductive film layer 2 can be effectively improved, so the thickness of the first conductive film layer 2 can be appropriately reduced, that is, in an optional embodiment, the thickness of the first conductive film layer 2 is less than the thickness of the second conductive film layer 11. Through the above arrangement, while ensuring the photoelectric conversion efficiency, the cost can be effectively reduced, and the use amount of the target material in the first conductive film layer 2 is reduced.
[0043] In summary, in the heterojunction solar cell provided by the embodiment of the utility model, when a passivation anti-reflection layer is provided on the top surface of the first fine grid, by making the first fine grid on the side and / or top surface of the first fine grid electrically connected to the conductive member, not only the photoelectric conversion performance of the heterojunction solar cell is ensured, but also the passivation anti-reflection layer on the top of the first fine grid does not need to be removed by an additional process, and the heterojunction solar cell formed has a simple structure and is suitable for large-scale production.
[0044] The introduction provided in the above steps is only used to help understand the structure, method and core idea of the utility model. For ordinary technicians in this technical field, the utility model can also be improved and modified without departing from the principle of the utility model, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.
Claims
1. A heterojunction solar cell, characterized in that: include: A silicon substrate (1), a first conductive film layer (2) arranged on one side of the silicon substrate (1) in a thickness direction, a first fine gate (100) arranged on the first conductive film layer (2), and a passivation anti-reflection layer (3) arranged in an area on the first conductive film layer (2) not covered by the first fine gate (100) and on a top surface of the first fine gate (100); Wherein, the side surface and / or the top surface of the first fine grid (100) is electrically connected to the conductive element (4).
2. The heterojunction solar cell according to claim 1, characterized in that: The heterojunction solar cell further comprises: a conductive channel (5) located on the top surface of the first fine grid (100) and distributed in the passivation anti-reflection layer (3); The top surface of the first fine grid (100) is electrically connected to the conductive member (4) through the conductive channel (5).
3. The heterojunction solar cell according to claim 1 or 2, characterized in that: The angle between the side surface of the first fine grid (100) and the first conductive film layer (2) towards the inner side of the first fine grid (100) is greater than or equal to 80° and less than or equal to 95°.
4. The heterojunction solar cell according to claim 1, characterized in that: Also includes: A first intrinsic crystalline silicon layer (6) and a first doped layer (7) doped with a first type of element are sequentially arranged between the silicon substrate (1) and the first conductive film layer (2).
5. The heterojunction solar cell according to claim 1, characterized in that: The conductive element (4) is the first main grid of the heterojunction solar cell.
6. The heterojunction solar cell according to claim 4, characterized in that: Also includes: A second intrinsic crystalline silicon layer (8), a second doping layer (9) doped with a second type of element, and a second conductive film layer (10) are sequentially arranged on the other side of the silicon substrate (1) in the thickness direction; A second fine grid (200) is arranged on the second conductive film layer (10), and a second main grid connected to the second fine grid (200).
7. The heterojunction solar cell according to claim 6, characterized in that: The thickness of the first conductive film layer (2) is smaller than the thickness of the second conductive film layer (10).
8. The heterojunction solar cell according to claim 6, characterized in that: The thickness of the first intrinsic crystalline silicon layer (6) and / or the second intrinsic crystalline silicon layer (8) is 1 to 50 nm; and / or, The thickness of the first fine grid (100) is 5-30 μm.
9. A photovoltaic module, comprising: The heterojunction solar cell according to any one of claims 1 to 8.