A solar cell and a photovoltaic module
By employing a grid line disconnection region design and solder ribbon ohmic contact in heterojunction solar cells, the problem of high contact resistance of pseudo-gate was solved, achieving higher photoelectric conversion efficiency and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- RISEN ENERGY (YIWU) CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-06-23
AI Technical Summary
The pseudo-busbar design of existing heterojunction solar cells has high contact resistance, which affects the fill factor and overall performance of the cell.
The design incorporates a break area in the grid line, with the solder ribbon covering the break area and making ohmic contact with the grid line and TCO film. This reduces the amount of slurry used, allows for direct ohmic contact with the cell surface, and lowers the contact resistance.
It reduces contact resistance, increases the photoelectric conversion power of the battery, reduces costs, and improves current collection efficiency.
Smart Images
Figure CN224402001U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of solar cell technology, and more specifically, to a solar cell and a photovoltaic module. Background Technology
[0002] With the rapid development of photovoltaic technology, heterojunction solar cells have been widely used in the photovoltaic field due to their high conversion efficiency and low temperature coefficient. Compared with traditional crystalline silicon solar cells, heterojunction cells adopt a structure combining amorphous and crystalline silicon, resulting in better passivation and higher open-circuit voltage. In existing technologies, the metallization process of heterojunction solar cells mainly uses screen printing technology to fabricate electrodes. To improve current collection efficiency and reduce series resistance, the industry generally adopts a main grid line design. In recent years, by optimizing the fine grid line arrangement and conductive material properties, some heterojunction cells have achieved a breakthrough in the design of grid lines without a main grid line. However, these cells still retain a pseudo-grid structure, which essentially simulates the function of a main grid by densely arranged fine grid lines. Although the pseudo-grid design in existing technologies can maintain a certain current collection capability, the contact between the pseudo grid and the transparent conductive oxide (TCO) layer is only a physical contact, resulting in a high contact resistance at the interface, which affects the fill factor and overall performance of the cell.
[0003] Therefore, there is an urgent need for a solar cell to solve the above-mentioned technical problems. Utility Model Content
[0004] This invention provides a solar cell and photovoltaic module that can reduce contact resistance and ensure the overall performance of the battery.
[0005] The embodiments of this utility model can be implemented as follows:
[0006] An embodiment of this utility model provides a solar cell, which includes:
[0007] Solar cells, including TCO films;
[0008] A grid line is disposed on the surface of the battery cell, and the grid line has a break area;
[0009] A solder ribbon is disposed on the surface of the battery cell and covers the disconnected area. The solder ribbon is in ohmic contact with both the grid lines and the TCO film.
[0010] Optionally, the solder strip makes ohmic contact with the gate line on at least one side of the disconnected region.
[0011] Optionally, the solder strip is in ohmic contact with the gate line on one side of the disconnected area, and the solder strip is spaced apart from the gate line on the other side of the disconnected area, with the spacing being 0.1mm-1mm.
[0012] Optionally, the surface of the solder strip is provided with a bonding layer, through which the solder strip makes ohmic contact with the TCO film and the gate line.
[0013] Optionally, the connecting layer is made of tin.
[0014] Optionally, the thickness of the connecting layer is 5μm-30μm.
[0015] Optionally, the cross-section of the welding strip is rectangular, triangular, V-shaped, or circular.
[0016] Optionally, the width of the welding strip is 0.05mm-0.3mm.
[0017] Optionally, the number of grid lines is several, and the several grid lines are arranged sequentially at intervals along the width direction of the battery cell, with each grid line having multiple break regions.
[0018] An embodiment of this utility model also provides a photovoltaic module, including a battery string, wherein the battery string includes solar cells.
[0019] The beneficial effects of the solar cells and photovoltaic modules of this utility model include, for example:
[0020] This solar cell includes a cell, grid lines, and a solder ribbon. The cell includes a TCO film. The grid lines are disposed on the surface of the cell and have interrupted areas. The solder ribbon is disposed on the interrupted areas, covering them, and makes ohmic contact with both the grid lines and the TCO film. In use, the grid lines are disposed on the surface of the cell, with interrupted areas, and the solder ribbon is disposed on the surface of the cell, covering the interrupted areas. The solder ribbon can make ohmic contact with both the grid lines and the TCO film simultaneously. Compared to existing technologies, the solder ribbon can directly make ohmic contact with the surface of the cell, reducing the amount of paste used, lowering costs, and eliminating the need for physical contact through paste, thus reducing contact resistance and increasing the photoelectric conversion power of the cell.
[0021] This photovoltaic module includes a string of cells, each containing solar cells. In use, grid lines are disposed on the surface of the solar cells, with interrupted areas. Solder ribbon is disposed on the surface of the solar cells, covering the interrupted areas of the grid lines. The solder ribbon can simultaneously make ohmic contact with both the grid lines and the TCO film. Compared to existing technologies, the solder ribbon can directly make ohmic contact with the surface of the solar cells, reducing the amount of paste used and lowering costs. Furthermore, the solder ribbon no longer needs to achieve physical contact through paste, reducing contact resistance and increasing the light-to-electricity conversion power of the cells. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a cross-sectional view of the center of the junction between the pseudo-main grid and the fine grid on a solar cell in the prior art.
[0024] Figure 2 This is a schematic diagram of the structure of the solar cell from a first-view perspective provided in this embodiment;
[0025] Figure 3 This is a schematic diagram of the structure of the solar cell from a second perspective provided in this embodiment;
[0026] Figure 4 This is a schematic diagram of the solar cell from a third-view perspective provided in this embodiment;
[0027] Figure 5 This is a schematic diagram of the solar cell from a fourth perspective provided in this embodiment.
[0028] Icons: 10-Solar cell; 11-Silicon wafer; 12-TCO film; 20-Grid line; 201-Break area; 30-Solder ribbon; 40-Connection layer. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0032] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0033] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0034] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.
[0035] Example
[0036] With the rapid development of photovoltaic technology, heterojunction solar cells have been widely used in the photovoltaic field due to their high conversion efficiency and low temperature coefficient. Compared with traditional crystalline silicon solar cells, heterojunction cells adopt a structure combining amorphous and crystalline silicon, resulting in better passivation and higher open-circuit voltage. In existing technologies, the metallization process of heterojunction solar cells mainly uses screen printing technology to fabricate electrodes. To improve current collection efficiency and reduce series resistance, the industry generally adopts a main grid line design. In recent years, by optimizing the fine grid line arrangement and conductive material properties, some heterojunction cells have achieved a breakthrough in the design of grid lines-free cells. However, these cells still retain pseudo-grid structures (such as...). Figure 1 As shown in the figure, it essentially simulates the function of the main grid by densely arranged fine grid lines. Although the pseudo-main grid design in the prior art can maintain a certain current collection capability, the contact between the pseudo-main grid and the transparent conductive oxide (TCO) layer is only a physical contact, and there is a high contact resistance at the interface, which affects the fill factor and overall performance of the battery.
[0037] Therefore, there is an urgent need for a solar cell to solve the above-mentioned technical problems.
[0038] Please refer to Figures 2-5 This embodiment provides a solar cell and a photovoltaic module. The photovoltaic module includes a cell string, and the cell string includes a plurality of solar cells. This photovoltaic module can effectively improve the aforementioned technical problems, reduce contact resistance, and ensure the overall performance of the battery.
[0039] In this embodiment, the solar cell is a heterojunction cell. In other embodiments, the solar cell may also be a TOPcon cell or a perovskite cell, etc., and no specific limitation is made here.
[0040] Please refer to Figures 2-5 The solar cell includes a cell 10, a grid line 20, and a solder ribbon 30. The cell 10 includes a TCO film 12. The grid line 20 is disposed on the surface of the cell 10 and has a break area 201. The solder ribbon 30 is disposed on the surface of the cell 10 and covers the break area 201. The solder ribbon 30 is in ohmic contact with both the grid line 20 and the TCO film 12.
[0041] It should be noted that existing solar cells still have pseudo-busbars, which are connected by paste, leading to an increase in paste usage. This increased paste usage can cause the grid lines 20 to become too thick or their width to exceed design limits, thereby increasing contact resistance, reducing current collection efficiency, and ultimately affecting the cell's conversion efficiency. To address this technical problem, the solar cell provided in this embodiment has grid lines 20 disposed on the surface of the cell 10, with a break area 201. A solder ribbon 30 is disposed on the surface of the cell 10, covering the break area 201 of the grid lines 20. The solder ribbon 30 can simultaneously make ohmic contact with both the grid lines 20 and the TCO film 12. Compared to existing technologies, the solder ribbon 30 can directly make ohmic contact with the surface of the cell 10, reducing paste usage and lowering costs. Furthermore, the solder ribbon 30 no longer needs to achieve physical contact through paste, reducing contact resistance and increasing the cell's light-to-electricity conversion power.
[0042] Specifically, there are several grid lines 20, which are arranged sequentially at intervals along the width direction of the battery cell 10. Each grid line 20 has multiple break regions 201, which are arranged sequentially at intervals along the length direction of the battery cell 10. In this embodiment, each grid line 20 has seven break regions 201. In other embodiments, the number of break regions 201 on each grid line 20 may be increased or decreased, and no specific limitation is made here.
[0043] In this embodiment, the silicon wafer 11 is cleaned and texturized, then an intrinsic amorphous silicon layer is deposited on two opposite surfaces of the silicon wafer 11, then a doped amorphous silicon layer is deposited on two opposite surfaces of the silicon wafer 11, then a TCO film 12 is deposited on two opposite surfaces of the silicon wafer 11, and gate lines 20 are formed on the surface of the TCO film 12 by printing.
[0044] Furthermore, the solder strip 30 makes ohmic contact with at least one side of the gate line 20 of the disconnected region 201. Please refer to [reference needed]. Figure 4 In this embodiment, the solder strip 30 and the grid lines 20 on both sides of the disconnected area 201 form ohmic contact.
[0045] Please refer to Figure 5In other embodiments, the solder ribbon 30 can make ohmic contact with the grid lines 20 on the left or right side of the disconnected region 201. The solder ribbon 30 and the grid lines 20 form an ohmic contact, thereby conducting the photocurrent generated by the solar cell 10 under illumination from the cell surface. Furthermore, the solder ribbon 30 can connect the grid lines 20 of two adjacent solar cells 10 to form a photovoltaic module. Specifically, when the solder ribbon 30 only makes ohmic contact with the grid lines 20 on one side of the disconnected region 201, the solder ribbon 30 and the grid lines 20 on the other side of the disconnected region 201 are spaced apart, with a spacing width of 0.1mm-1mm. The spacing width can be 0.1mm, 0.3mm, 0.6mm, or 1mm. No specific limitation is made here.
[0046] It should also be noted that the surface of the solder ribbon 30 is provided with a bonding layer 40, through which the solder ribbon 30 makes ohmic contact with the TCO film 12 and the gate line 20. Specifically, the bonding layer 40 is made of tin. In this embodiment, a tin coating is formed on the surface of the solder ribbon 30.
[0047] Furthermore, during the lamination of the photovoltaic module, the high temperature conditions of lamination cause the tin material on the surface of the solder ribbon 30 to melt, thereby coating the surface of the solder ribbon 30 and achieving ohmic contact between the solder ribbon 30 and the grid line 20 and the TCO film 12.
[0048] Specifically, the thickness of the connecting layer 40 is 5μm-30μm. In this embodiment, the thickness of the connecting layer 40 is 20μm. In other embodiments, the thickness of the connecting layer 40 may also be 5μm, 10μm, or 30μm, and no specific limitation is made here.
[0049] It should also be noted that during the tinning process of the solder ribbon 30 in the disconnected area 201, conductive adhesive is first used to fix the solder ribbon 30. During the high temperature of the photovoltaic module lamination process, the connecting layer 40 on the surface of the solder ribbon 30 is tinned, thereby making ohmic contact with the grid line 20 and the TCO film 12.
[0050] In this embodiment, the solder strip 30 makes ohmic contact with the grid lines 20 on both sides of the disconnected region 201. The cross-section of the solder strip 30 is circular. In order to ensure that the solder strip 30 can achieve a stable connection with the grid lines 20, the width of the disconnected region 201 is less than half the diameter of the solder strip 30.
[0051] In other embodiments, the cross-section of the solder strip 30 can be a rectangular structure, a V-shaped structure, or a triangular structure. In order to ensure that the solder strip 30 can be stably connected with the grid line 20, the width of the disconnected region 201 is not greater than the width of the solder strip 30.
[0052] It should be noted that the cross-section of the welding strip 30 refers to the shape of the cut surface perpendicular to the length direction.
[0053] In this embodiment, the width of the solder strip 30 is 0.05mm-0.3mm. Specifically, the width of the solder strip 30 can be 0.05mm. In other embodiments, the width of the solder strip 30 can also be 0.1mm, 0.2mm or 0.3mm, and no specific limitation is made here.
[0054] The solar cell, i.e., photovoltaic module, provided in this embodiment has at least the following advantages:
[0055] Existing solar cells still suffer from pseudo-busbars, which are connected via paste, leading to increased paste usage. This increased paste usage results in excessively thick or wider grid lines 20, increasing contact resistance, reducing current collection efficiency, and consequently affecting the cell's conversion efficiency. To address this issue, the solar cell provided in this embodiment has grid lines 20 disposed on the surface of the cell 10, with a break area 201. A solder ribbon 30 is disposed on the surface of the cell 10, covering the break area 201 of the grid lines 20. The solder ribbon 30 can simultaneously make ohmic contact with both the grid lines 20 and the TCO film 12. Compared to existing technologies, the solder ribbon 30 can directly make ohmic contact with the surface of the cell 10, reducing paste usage and lowering costs. Furthermore, the solder ribbon 30 no longer requires physical contact via paste, reducing contact resistance and increasing the cell's light-to-electricity conversion power.
[0056] In summary, this utility model provides a solar cell and a photovoltaic module. The solar cell includes a cell 10, grid lines 20, and a solder ribbon 30. The cell 10 includes a TCO film 12. The grid lines 20 are disposed on the surface of the cell 10 and have a break area 201. The solder ribbon 30 is disposed on the break area 201 and covers the break area 201. The solder ribbon 30 is in ohmic contact with both the grid lines 20 and the TCO film 12. In use, the grid lines 20 are disposed on the surface of the cell 10 and have a break area 201. The solder ribbon 30 is disposed on the surface of the cell 10 and covers the break area 201 of the grid lines 20. The solder ribbon 30 can simultaneously make ohmic contact with both the grid lines 20 and the TCO film 12. Compared to existing technologies, the solder ribbon 30 can make direct ohmic contact with the surface of the solar cell 10, reducing the amount of paste used and lowering costs. Furthermore, the solder ribbon 30 no longer needs to achieve physical contact through paste, reducing contact resistance and increasing the photoelectric conversion power of the cell.
[0057] This photovoltaic module includes a cell string, which includes solar cells. In use, grid lines 20 are disposed on the surface of the solar cell 10, and the grid lines 20 have disconnected areas 201. Solder ribbon 30 is disposed on the surface of the solar cell 10 and covers the disconnected areas 201 of the grid lines 20. The solder ribbon 30 can simultaneously make ohmic contact with both the grid lines 20 and the TCO film 12. Compared to existing technologies, the solder ribbon 30 can directly make ohmic contact with the surface of the solar cell 10, reducing the amount of paste used and lowering costs. Furthermore, the solder ribbon 30 no longer needs to achieve physical contact through paste, reducing contact resistance and improving the light-to-electricity conversion power of the cell.
[0058] Comparative Example
[0059] A comparative example provides a solar cell including a cell 10, grid lines 20, and solder ribbons 30. The grid lines 20 are disposed on the surface of the cell 10, and the solder ribbons 30 are connected to the grid lines 20. The solder ribbons 30 achieve physical contact through a paste and a TCO film 12.
[0060] Test case
[0061] The performance of the solar cells in the examples and comparative examples was tested and compared, and the test results are shown in Table 1.
[0062] Table 1
[0063]
[0064] It can be seen that, compared with the solar cell of the embodiment, the solar cell of the embodiment uses less paste, has higher conversion efficiency, and better performance.
[0065] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. A solar cell, characterized in that, include: The solar cell (10) includes a TCO film (12); A grid line (20) is disposed on the surface of the battery cell (10), and the grid line (20) has a break region (201); A solder ribbon (30) is disposed on the surface of the battery cell (10) and covers the disconnected area (201). The solder ribbon (30) is in ohmic contact with both the grid line (20) and the TCO film (12).
2. The solar cell according to claim 1, characterized in that, The solder strip (30) is in ohmic contact with the grid line (20) on at least one side of the disconnected region (201).
3. The solar cell according to claim 2, characterized in that, The solder strip (30) is in ohmic contact with the gate line (20) on one side of the disconnected area (201), and the solder strip (30) is spaced apart from the gate line (20) on the other side of the disconnected area (201), with the spacing being 0.1mm-1mm.
4. The solar cell according to claim 1, characterized in that, The surface of the solder strip (30) is provided with a connecting layer (40), and the solder strip (30) is in ohmic contact with the TCO film (12) and the grid line (20) through the connecting layer (40).
5. The solar cell according to claim 4, characterized in that, The connecting layer (40) is made of tin.
6. The solar cell according to claim 4, characterized in that, The thickness of the connecting layer (40) is 5μm-30μm.
7. The solar cell according to claim 1, characterized in that, The cross-section of the welding strip (30) is rectangular, triangular, V-shaped or circular.
8. The solar cell according to claim 1, characterized in that, The width of the welding strip (30) is 0.05mm-0.3mm.
9. The solar cell according to claim 1, characterized in that, The number of grid lines (20) is several, and the several grid lines (20) are arranged sequentially at intervals along the width direction of the battery cell (10). Each grid line (20) has multiple disconnected regions (201).
10. A photovoltaic module, characterized in that, It includes a battery string, wherein the battery string includes the solar cell according to any one of claims 1-9.