Solar cell
By providing thin silver paste and non-silver metal layers in the electrode layer of the TOPCon solar cell, the problem of high manufacturing costs due to the large amount of silver paste used is solved, and cost reduction and battery efficiency are achieved.
Patent Information
- Application Number
- CN202421087791.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-05-17
AI Technical Summary
The manufacturing cost of TOPCon solar cells is high, mainly because silver paste is used in electrode materials, which leads to a higher cost.
In the positive electrode layer and the back electrode layer of the solar cell, a silver paste layer and a non-silver metal layer are respectively provided, and the thickness of the silver paste layer is controlled between 0-5 μm, and when the cost of the non-silver metal layer is low, it is not possible to use the silver paste layer to be lower. , reduce the amount of silver paste used.
By reducing the thickness and usage of the silver paste layer, the manufacturing cost of solar cells is reduced, while ensuring the contact performance of the electrode layer and low metal recombination, maintaining the battery efficiency.
Smart Images
Figure CN222442195U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solar cells, in particular to a solar cell. Background Art
[0002] With the development of the photovoltaic industry, high-efficiency modules made of PERC or TOPCon cells have gradually become mainstream products in the market. TOPCon is the abbreviation of Tunnel Oxide Passivated Contact solar cell.
[0003] At present, the silver paste can form a good contact with the n-type poly layer and the metal composite in contact with the n-type poly layer is controlled at 100fA / cm 2 Therefore, the electrode material of TOPCon battery adopts silver paste, and the thickness of silver paste is greater than or equal to 10μm. As the price of silver point continues to rise, the manufacturing cost of TOPCon battery is getting higher and higher. Utility Model Content
[0004] In view of this, the utility model provides a solar cell to solve the problem of high cost caused by using silver paste as the electrode material of the battery.
[0005] The utility model provides a solar cell, comprising: a substrate, a positive structure layer, a positive passivation layer, a positive electrode layer, a back structure layer, a back passivation layer and a back electrode layer, wherein the positive structure layer, the positive passivation layer and the positive electrode layer are sequentially arranged on the front side of the substrate, and the back structure layer, the back passivation layer and the back electrode layer are sequentially arranged on the back side of the substrate, the positive electrode layer and / or the back electrode layer comprise a silver paste layer and a non-silver metal layer, the non-silver metal layer is arranged on the side of the silver paste layer facing away from the substrate, and the thickness of the silver paste layer is greater than 0 and less than 5 μm.
[0006] Beneficial effects: The positive electrode layer and the back electrode layer are set as a silver paste layer and a non-silver metal layer, and the thickness of the silver paste layer is less than 5μm and the cost of the non-silver metal is much lower than that of silver. Compared with the prior art in which the back electrode layer is entirely made of silver paste, the thickness of the silver paste layer is thinner, which can reduce the use of silver paste and save costs. The silver paste layer is in contact with the structural layer to ensure contact performance and low metal composite, thereby ensuring that the battery efficiency remains the same.
[0007] In an optional embodiment, the non-silver metal layer is an aluminum paste layer or a copper paste layer.
[0008] Beneficial effects: The price of aluminum paste is about 100 yuan / kg, and the cost of solar cells is low.
[0009] In an optional embodiment, the thickness of the positive electrode layer is greater than 0 and less than 20 μm.
[0010] Beneficial effect: The thickness of the positive electrode layer is set in the range of 0-20 μm, ensuring that the resistance value of the positive electrode layer is within a suitable range.
[0011] In an optional implementation, the thickness of the back electrode layer is greater than 0 and less than 20 μm.
[0012] Beneficial effect: The thickness of the back electrode layer is set in the range of 0-20 μm, so that the resistance value of the back electrode layer is in a suitable range.
[0013] In an optional implementation, the back electrode layer partially covers the back passivation layer.
[0014] Beneficial effect: The silver paste layer partially covers the back passivation layer, which significantly reduces the silver paste consumption without affecting the efficiency of the solar cell.
[0015] In an optional implementation, the positive electrode layer partially covers the positive passivation layer.
[0016] Beneficial effect: The silver paste layer partially covers the positive passivation layer, which not only further reduces the amount of silver paste used, but also ensures the efficiency of the solar cell.
[0017] In an optional embodiment, the positive electrode layer includes at least two positive electrodes disposed at intervals, and the back electrode layer includes at least two back electrodes disposed at intervals.
[0018] Beneficial effect: The efficiency of the solar cell can be ensured by at least two electrodes.
[0019] In an optional implementation, the positive structure layer is a positive doping layer.
[0020] In an optional implementation, the back structure layer includes a tunneling oxide layer and a polysilicon layer, and the tunneling oxide layer is disposed between the polysilicon layer and the substrate.
[0021] In an optional implementation, the back structure layer is a back doping layer. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 This is a schematic structural diagram of a front structure of a solar cell according to an embodiment of the utility model;
[0024] Figure 2 This is a schematic structural diagram of a back side structure of a solar cell according to an embodiment of the utility model;
[0025] Figure 3 A partial structural schematic diagram of another back surface structure of a solar cell according to an embodiment of the utility model;
[0026] Figure 4 for Figure 3 The schematic diagram of the structure in which a silver paste layer is disposed locally outside the back passivation layer is shown;
[0027] Figure 5 for Figure 4 The schematic diagram of the structure in which a non-silver metal layer is arranged outside the silver paste layer is shown.
[0028] Description of reference numerals:
[0029] 1. Substrate;
[0030] 2. Positive doping layer;
[0031] 3. Positive passivation layer;
[0032] 4. positive electrode layer; 401. silver paste layer; 402. non-silver metal layer;
[0033] 601, tunnel oxide layer; 602, polysilicon layer; 603, back doping layer;
[0034] 7. Back passivation layer;
[0035] 8. Back electrode layer. DETAILED DESCRIPTION
[0036] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0037] Combine the following Figures 1 to 5 , describing an embodiment of the utility model.
[0038] According to an embodiment of the utility model, a solar cell is provided, comprising: a substrate 1, a positive structure layer, a positive passivation layer 3, a positive electrode layer 4, a back structure layer, a back passivation layer 7 and a back electrode layer 8, the positive structure layer, the positive passivation layer 3 and the positive electrode layer 4 are sequentially arranged on the front side of the substrate 1, the back structure layer, the back passivation layer 7 and the back electrode layer 8 are sequentially arranged on the back side of the substrate 1, the positive electrode layer 4 and the back electrode layer 8 both comprise a silver paste layer 401 and a non-silver metal layer 402, the non-silver metal layer 402 is arranged on the side of the silver paste layer 401 facing away from the substrate 1, and the thickness of the silver paste layer 401 is greater than 0 and less than 5 μm.
[0039] When the solar cell of the present embodiment is used to manufacture the solar cell, a positive structural layer is arranged on the front side of the substrate 1, a positive passivation layer 3 is arranged on the outer side of the positive structural layer, a silver paste layer 401 is arranged on the outer side of the positive passivation layer 3, a non-silver metal layer 402 is arranged on the outer side of the silver paste layer 401, and then heat treatment is performed, and the silver paste layer 401 penetrates the positive passivation layer 3 and contacts the positive structural layer; a back structural layer is arranged on the back side of the substrate 1, a back passivation layer 7 is arranged on the outer side of the back structural layer, a silver paste layer 401 is arranged on the outer side of the back passivation layer 7, a non-silver metal layer 402 is arranged on the outer side of the silver paste layer 401, and then heat treatment is performed, and the silver paste layer 401 penetrates the back passivation layer 7 and contacts the back structural layer. The positive electrode layer 4 and the back electrode layer 8 are set to be a silver paste layer 401 and a non-silver metal layer, and the thickness of the silver paste layer 401 is less than 5μm and the cost of the non-silver metal is much lower than that of silver. Compared with the prior art in which the back electrode layer is entirely made of silver paste, the thickness of the silver paste layer 401 is thinner, which can reduce the use of silver paste and save costs. The silver paste layer 401 is in contact with the structural layer to ensure contact performance and low metal composite, thereby ensuring that the battery efficiency remains the same.
[0040] It should be noted that after the thickness of the silver paste layer 401 becomes thinner, the resistance value of the silver paste layer 401 becomes smaller. In order to ensure that the resistance value remains unchanged, it is necessary to add a non-silver metal layer 402, which can not only ensure that the resistance value remains unchanged, but also reduce costs.
[0041] In another embodiment, one of the positive electrode layer 4 and the back electrode layer 8 includes a silver paste layer 401 and a non-silver metal layer 402 .
[0042] In one embodiment, the non-silver metal layer is an aluminum paste layer or a copper paste layer. The price of aluminum paste is about 100 yuan / kg, and the cost of solar cells is low.
[0043] If the electrode layer is made entirely of aluminum paste or copper paste, when the aluminum paste or copper paste contacts the structural layer, the metal composite is > 1000fA / cm 2The metal composite is large and the contact performance is not as good as silver paste, which will cause a significant decrease in the open circuit voltage and fill factor of the TOPCon battery, thereby affecting the battery efficiency. The electrode layer of this embodiment uses silver paste in part and aluminum paste or copper paste in part, which reduces the consumption of silver paste, and the cost of aluminum paste or copper paste is also low, reducing the manufacturing cost.
[0044] It should be noted that the current price of silver paste is about 7,000 yuan / kg.
[0045] In one embodiment, the thickness of the positive electrode layer 4 is greater than 0 and less than 20 μm. The thickness of the positive electrode layer 4 is set in the range of 0-20 μm to ensure that the resistance value of the positive electrode layer is within a suitable range.
[0046] In one embodiment, the thickness of the back electrode layer 8 is greater than 0 and less than 20 μm. The thickness of the back electrode layer 8 is set in the range of 0-20 μm, so that the resistance value of the negative electrode layer is within a suitable range.
[0047] In one embodiment, the back electrode layer 8 partially covers the back passivation layer 7, and the silver paste layer 401 partially covers the back passivation layer 7, so that the silver paste consumption is significantly reduced without affecting the efficiency of the solar cell.
[0048] In one embodiment, Figure 1 As shown, the positive electrode layer 4 partially covers the positive passivation layer 3, and the silver paste layer 401 partially covers the positive passivation layer 3, which not only further reduces the amount of silver paste used, but also ensures the efficiency of the solar cell.
[0049] In one embodiment, the positive electrode layer 4 includes at least two positive electrodes disposed at intervals, and the back electrode layer 8 includes at least two back electrodes disposed at intervals. The efficiency of the solar cell can be ensured by at least two electrodes.
[0050] In one embodiment, Figure 1 As shown, the positive structural layer is the positive doping layer 2. The front side of the solar cell is composed of a substrate 1, a positive doping layer 2, and a positive passivation layer 3 from the inside to the outside. A silver paste layer 401 is partially disposed outside the positive passivation layer 3. The thickness of the silver paste layer 401 is relatively thin, less than 5 μm. A non-silver metal layer 402 such as an aluminum paste layer or a copper paste layer is disposed outside the silver paste layer 401, and then heat treatment is performed so that the silver paste layer 401 is in contact with the positive doping layer 2.
[0051] Furthermore, the positive doping layer 2 is specifically a silicon doping layer or the like, and the substrate 1 is specifically a silicon substrate or the like.
[0052] In one embodiment, Figures 3 to 5As shown, the back structure layer includes a tunneling oxide layer 601 and a polysilicon layer 602, and the tunneling oxide layer 601 is arranged between the polysilicon layer 602 and the substrate 1. The back of the solar cell is composed of the substrate 1, the tunneling oxide layer 601, the polysilicon layer 602, and the back passivation layer 7 from the inside to the outside. A silver paste layer 401 is partially arranged outside the back passivation layer 7. The thickness of this silver paste layer 401 is relatively thin, less than 5μm; a non-silver metal layer 402 such as an aluminum paste layer or a copper paste layer is arranged outside the silver paste layer 401, and then heat treatment is performed, so that the silver paste layer 401 is in contact with the polysilicon layer 602. The polysilicon layer 602 is specifically an N-type poly layer.
[0053] Furthermore, the front passivation layer 3 and the back passivation layer 7 are specifically silicon nitride films or other passivation films.
[0054] In another embodiment, if Figure 2 As shown, the back structure layer is a back doping layer 603. The back side of the solar cell is composed of a substrate 1, a back doping layer 603, and a back passivation layer 7 from the inside to the outside. A silver paste layer 401 is partially disposed outside the back passivation layer 7. The thickness of the silver paste layer 401 is relatively thin, less than 5 μm. A non-silver metal layer 402 such as an aluminum paste layer or a copper paste layer is disposed outside the silver paste layer 401, and then heat treatment is performed to form contact between the silver paste layer 401 and the back doping layer 603. Furthermore, the back doping layer 603 is specifically a silicon doping layer.
[0055] In related technologies, all electrode materials are made of silver paste. As the domestic silver dot price continues to rise, the price of silver paste has also increased from more than 5,000 yuan / kg to over 7,000 yuan / kg, and the manufacturing cost of solar cells is getting higher and higher.
[0056] To reduce manufacturing costs, in this embodiment, the solar cell uses a laminated metal printing technology and uses a thinner silver paste layer 401 to contact the doped layer or polysilicon layer 602, thereby ensuring the contact performance of the thinner silver paste layer 401 with the doped layer or polysilicon layer 602 and lower metal composite, thereby achieving a significant reduction in silver paste consumption without affecting the efficiency of the solar cell; aluminum paste or copper paste is used outside the silver paste layer 401, and the aluminum paste or copper paste mainly plays a conductive role, and also reduces the use of silver paste, has a simple structure, and is easy to mass produce.
[0057] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.
Claims
1. A solar cell, characterized in that: include: A substrate (1), a positive structural layer, a positive passivation layer (3), a positive electrode layer (4), a back structural layer, a back passivation layer (7) and a back electrode layer (8); the front side of the substrate (1) is provided with the positive structural layer, the positive passivation layer (3) and the positive electrode layer (4) in sequence; the back side of the substrate (1) is provided with the back structural layer, the back passivation layer (7) and the back electrode layer (8) in sequence; the positive electrode layer (4) and / or the back electrode layer (8) comprise a silver paste layer and a non-silver metal layer; the non-silver metal layer is provided on the side of the silver paste layer facing away from the substrate (1); the thickness of the silver paste layer is greater than 0 and less than 5 μm.
2. The solar cell according to claim 1, characterized in that The non-silver metal layer is an aluminum paste layer or a copper paste layer.
3. The solar cell according to claim 1, characterized in that The thickness of the positive electrode layer (4) is greater than 0 and less than 20 μm.
4. The solar cell according to claim 1, characterized in that The thickness of the back electrode layer (8) is greater than 0 and less than 20 μm.
5. The solar cell according to any one of claims 1 to 4, characterized in that The back electrode layer (8) partially covers the back passivation layer (7).
6. The solar cell according to any one of claims 1 to 4, characterized in that: The positive electrode layer (4) partially covers the positive passivation layer (3).
7. The solar cell according to any one of claims 1 to 4, characterized in that The positive electrode layer (4) comprises at least two positive electrodes arranged at intervals, and the back electrode layer (8) comprises at least two back electrodes arranged at intervals.
8. The solar cell according to any one of claims 1 to 4, characterized in that The positive structural layer is a positive doping layer (2).
9. The solar cell according to any one of claims 1 to 4, characterized in that: The back structure layer comprises a tunneling oxide layer (601) and a polysilicon layer (602), and the tunneling oxide layer (601) is arranged between the polysilicon layer (602) and the substrate (1).
10. The solar cell according to any one of claims 1 to 4, characterized in that: The back structure layer is a back doping layer (603).