Grid line structure for preventing edge of photovoltaic cell from blackening
By adding thin grid lines to the contact area of the TOPCon solar cell, the contact surface between the cell and the crawler thimble is optimized, and the blackening problem caused by uneven temperature during the sintering process is solved, and the yield and efficiency improvement is achieved.
Patent Information
- Application Number
- CN202421210036.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-05-30
AI Technical Summary
During the sintering process, the existing TOPCon solar cell has a blackened position due to uneven thimble position temperature of the battery cell, which affects efficiency and yield.
Adopt a gate wire structure that prevents blackening of the edge of the photovoltaic cell. By adding thin gate wires to the contact area of the thimble, the contact area within a unit area is increased, and the contact surface between the battery cell and the crawler thimble is optimized, thereby reducing the problem of temperature unevenness. .
By increasing the contact area by 10%-200%, the yield of the battery cell can be improved by 1%-2% and efficiency by 0.03%-0.05%.
Smart Images
Figure CN222509905U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of crystalline silicon cell sheet preparation, in particular to a grid line structure for preventing the edge of a photovoltaic cell from becoming black. Background Art
[0002] TOPCon is a tunnel oxide passivated contact solar cell technology based on the principle of selective carriers. Its cell structure is an N-type silicon cell. An ultra-thin silicon oxide layer is prepared on the back of the cell, and then a thin layer of doped silicon is deposited. The two together form a passivated contact structure, which effectively reduces surface recombination and metal contact recombination, and provides more room for further improvement of N-PERT cell conversion efficiency. Its production process is texturing, boron diffusion, BSG removal + alkaline polishing, deposition of amorphous silicon, RCA, ALD, front and back coating, and metallization. The metallization process is to print silver paste electrodes on the surface of the cell, and sinter them in a sintering furnace to form a good ohmic contact between the metal electrode and the silicon wafer.
[0003] The current pattern preparation grid line spacing is too large and the track ejector position is relatively fixed, resulting in uneven heating of the ejector position during sintering of the battery cell. After high-temperature sintering, the ejector position of the battery cell turns black, affecting efficiency and yield. Summary of the invention
[0004] In order to solve the above technical problems, the inventors have obtained the technical solution of the utility model through practice and summary. The utility model adopts the following technical solution:
[0005] A grid line structure for preventing the edge of a photovoltaic cell from becoming black, comprising:
[0006] The pin-contact gate line structure is composed of a plurality of parallel thin gate lines;
[0007] A main grid line structure, wherein the main grid line structure comprises a plurality of parallel thin grid lines 2 and a plurality of parallel main grid lines, wherein the thin grid lines 2 and the main grid lines are arranged vertically;
[0008] The main grid line is connected to the first fine grid line and the second fine grid line;
[0009] The total contact area between the thin grid line 1 of the pin-contact grid line structure and the cell section is 10-200% greater than the total contact area between the thin grid line 2 of the main grid line structure and the cell section per unit area.
[0010] Preferably, the width of the ejector pin contacting the gate line structure is greater than or equal to the ejector pin width and less than or equal to the main gate line structure.
[0011] Preferably, the sum of the widths of the thin gate lines 1 in the contact pin region per unit area is 10-200% greater than the sum of the widths of the thin gate lines 2 in the main gate line structure.
[0012] Preferably, the total number of one thin grid line in the contact ejector region per unit area is 10-200% greater than the total number of two thin grid lines in the main grid structure.
[0013] Preferably, the first fine gate line includes a first fine gate line and a second fine gate line, the first fine gate line is located on a side close to the main gate line structure, and the second fine gate line is located on a side away from the main gate line structure.
[0014] Preferably, the width of the second thin gate line is 5-20% greater than the width of the first thin gate line.
[0015] Preferably, the ejector pin contacting the gate line structure further comprises a plurality of temperature averaging lines, which are distributed on a side away from the main gate line structure and arranged in a direction perpendicular to the direction of the second fine gate line.
[0016] Preferably, the temperature-averaging lines are distributed at intervals, and two ends of the temperature-averaging lines are respectively connected to corresponding fine grid lines 2.
[0017] Preferably, the temperature-averaging line is a structure that is wide at both ends and thin in the middle, or a wavy structure.
[0018] Preferably, the end of the temperature-averaging line extends into the interval region between the fine gate lines, and the extension length is less than half of the width of the interval region.
[0019] Compared with the prior art, the utility model has the following beneficial effects:
[0020] The grid line structure of the cell is locally optimized, and the EL defect is reduced by optimizing the contact surface between the cell and the track pin, which is reflected in the improvement of yield and efficiency. Theoretically, by increasing the contact area by 10%-200% at the edge of the grid line structure (corresponding to the pin contact area), the grid line spacing or spacing space in the pin contact area can be reduced by increasing the line width or number of lines, thereby achieving a 1%-2% improvement in the yield of the cell and a 0.03%-0.05% improvement in efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Schematic diagram of the grid line structure of the utility model Figure 1 ;
[0022] Figure 2 Schematic diagram of the grid line structure of the utility model Figure 2 ;
[0023] Figure 3 Schematic diagram of the grid line structure of the utility model Figure 3 ;
[0024] Figure 4 It is a schematic diagram of a thin grid line 1 of the utility model;
[0025] Figure 5 Schematic diagram of the grid line structure of the utility model Figure 4 ;
[0026] Figure 6 for Figure 5 The schematic diagram of the mean temperature line Figure 1 ;
[0027] Figure 7 for Figure 5 The schematic diagram of the mean temperature line Figure 2 ;
[0028] Figure 8 Schematic diagram of the grid line structure of the utility model Figure 5 ;
[0029] Fig. 9 for Figure 8 The schematic diagram of the mean temperature line Figure 1 ;
[0030] Fig.10 for Figure 8 The schematic diagram of the mean temperature line Figure 2 .
[0031] In the figure: 10, ejector pin contacting gate line structure; 11, thin gate line 1; 111, first thin gate line; 112, second thin gate line; 12, temperature balancing line;
[0032] 20. Main grid line structure; 21. Main grid line; 22. Fine grid line 2. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.
[0034] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0035] Embodiment 1, as Figure 1 As shown, a grid line structure for preventing the edge of a photovoltaic cell from blackening comprises:
[0036] The top pin contact gate line structure 10 is a plurality of parallel thin gate lines 11;
[0037] The main grid line structure 20 includes a plurality of parallel thin grid lines 22 and a plurality of parallel main grid lines 21, wherein the thin grid lines 22 and the main grid lines 21 are arranged vertically;
[0038] The main grid line 21 is connected to the fine grid line 1 11 and the fine grid line 2 22;
[0039] The total contact area between the thin gate line 11 of the pin contact gate line structure 10 and the end surface of the cell is 10-200% greater than the total contact area between the thin gate line 22 of the main gate line structure 20 and the end surface of the cell, preferably 50%.
[0040] The grid line structure of the cell is locally optimized, and the EL defect is reduced by optimizing the contact surface between the cell and the track pin, which is reflected in the improvement of yield and efficiency. Theoretically, by increasing the contact area by 10%-200% at the edge of the grid line structure (corresponding to the pin contact area), the grid line spacing or spacing space in the pin contact area can be reduced by increasing the line width or number of lines, thereby achieving a 1%-2% improvement in the yield of the cell and a 0.03%-0.05% improvement in efficiency.
[0041] The width of the ejector pin contacting the gate line structure 10 is greater than or equal to the ejector pin width and less than or equal to the width of the main gate line structure 20. Figure 2 As shown, a specific implementation is that the width of the ejector pin contact gate line structure 10 is in the range of 1-3 times the ejector pin width. This method can be set in a targeted manner, save the amount of silver paste used, and effectively solve the problem of blackening of the battery cell. Figure 1 As shown, another method is to have the same width as the main grid line structure 20 , which can also effectively solve the blackening problem and prevent the width of the region where the ejector pin contacts the grid line structure 10 from being misaligned with the ejector pin region.
[0042] like Figure 3 As shown, one way is: the number of lines is equal, the width is different, and the total width of the fine grid line 11 in the contact pin area per unit area is 10-200% greater than the total width of the fine grid line 22 in the main grid line structure 20. The problem of uneven temperature can be effectively solved by encrypting the area.
[0043] like Figure 1 As shown, another method is: the width is equal, the number of lines is different, and the total number of fine grid lines 11 per unit area of the contact pin area is 10-200% more than the total number of fine grid lines 22 of the main grid line structure 20. Increasing the width can effectively solve the problem, but the effect is slightly worse than the above method.
[0044] Embodiment 2, as Figure 4 As shown, in a grid line structure for preventing the edge of a photovoltaic cell from turning black, the thin grid line 11 includes a first thin grid line 111 and a second thin grid line 112, the first thin grid line 111 is located on a side close to the main grid line structure 20, and the second thin grid line 112 is located on a side away from the main grid line structure 20. The length of the second thin grid line 112 is about one-half to one-third to one-fourth of the length of the first thin grid line 111.
[0045] In one embodiment, the width of the second thin gate line 112 is 5-20%, preferably 10%, greater than the width of the first thin gate line 111. The blackening problem caused by uneven temperature can be further effectively solved by specifically widening the width of the second thin gate line 112 near the edge.
[0046] Embodiment 3, as Figure 5 As shown, in a grid line structure for preventing the blackening of the edge of a photovoltaic cell, the pin contact grid line structure 10 also includes a plurality of temperature-averaging lines 12, which are distributed on a side away from the main grid line structure 20, and are arranged in a direction perpendicular to the direction of the thin grid line 22. The two ends of the temperature-averaging line 12 are respectively connected to the corresponding thin grid line 11. The temperature-averaging line 12 can be used to perform targeted temperature-averaging treatment in the non-grid line coverage area near the edge position area. It can also be one, that is, Figure 5 The temperature-averaging lines 12 on the same side of the circuit are the same and can be arranged in parallel with the main grid lines 21 .
[0047] Embodiment 4, as Figure 5 and Figure 6 As shown, in a grid line structure for preventing the edge of a photovoltaic cell from turning black, the temperature-averaging lines 12 are spaced apart, and the temperature-averaging lines 12 are wide at both ends and thin in the middle. The width of the ends can effectively obtain the temperature and average the temperature. The temperature-averaging lines 12 can also be linear or wavy, and the wavy shape is also the same, such as Figure 7 shown.
[0048] Embodiment 5, in a grid line structure for preventing the edge of a photovoltaic cell from turning black, such as Figure 8 value Fig.10 As shown, the end of the temperature-averaging line 12 extends into the spacing area of the fine grid line 22, and the extension length is less than half of the width of the spacing area, excluding the endpoint value. In this embodiment, the temperature-averaging lines 12 can be distributed at equal intervals or at intervals.
[0049] The yield of the battery cell using the technical solution of the present application can be improved by 1%-2% and the efficiency can be improved by 0.03%-0.05%.
[0050] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited to this. The replacement can be a replacement of part of the structure, device, method step, or a complete technical solution. Equivalent replacement or change based on the technical solution and inventive concept of the utility model should be included in the protection scope of the utility model.
Claims
1. A grid line structure for preventing the edge of a photovoltaic cell from turning black, characterized in that: include: A pin-contact gate line structure (10), wherein the pin-contact gate line structure (10) is a plurality of parallel thin gate lines (11); A main grid line structure (20), the main grid line structure (20) comprising a plurality of parallel arranged fine grid lines 2 (22) and a plurality of parallel arranged main grid lines (21), wherein the fine grid lines 2 (22) and the main grid lines (21) are arranged vertically; The main grid line (21) is connected to the fine grid line 1 (11) and the fine grid line 2 (22); The total contact area between the thin grid line 1 (11) of the pin contact grid line structure (10) and the cell section is 10-200% greater than the total contact area between the thin grid line 2 (22) of the main grid line structure (20) and the cell section per unit area.
2. A grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 1, characterized in that: The width of the ejector pin contacting the gate line structure (10) is greater than or equal to the ejector pin width and less than or equal to the width of the main gate line structure (20).
3. The grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 1, characterized in that: The total width of the fine grid line 1 (11) in the contact pin region per unit area is 10-200% greater than the total width of the fine grid line 2 (22) of the main grid line structure (20).
4. The grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 1, characterized in that: The total number of fine grid lines 1 (11) in the contact pin region per unit area is 10-200% greater than the total number of fine grid lines 2 (22) in the main grid line structure (20).
5. The grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 1, characterized in that: The fine gate line one (11) comprises a first fine gate line (111) and a second fine gate line (112), wherein the first fine gate line (111) is located on a side close to the main gate line structure (20), and the second fine gate line (112) is located on a side away from the main gate line structure (20).
6. A grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 5, characterized in that: The width of the second thin gate line (112) is 5-20% greater than the width of the first thin gate line (111).
7. A grid line structure for preventing the edge of a photovoltaic cell from turning black according to any one of claims 1 to 6, characterized in that: The pin-contact gate line structure (10) further comprises a plurality of temperature-averaging lines (12), which are distributed on a side away from the main gate line structure (20) and arranged in a direction perpendicular to the direction of the fine gate line one (11).
8. The grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 7, characterized in that: The temperature-averaging lines (12) are distributed at intervals, and two ends of the temperature-averaging lines (12) are respectively connected to corresponding fine grid lines one (11).
9. A grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 8, characterized in that: The temperature-averaging line (12) is a structure that is wide at both ends and thin in the middle, or a wavy structure.
10. The grid line structure for preventing the edge of a photovoltaic cell from turning black according to claim 8, characterized in that: The end of the temperature-averaging line (12) extends into the spacing region of the fine grid line 1 (11), and the extension length is less than half of the width of the spacing region.