Low-pressure diffusion air inlet pipe of single-crystal Topcon battery

Abstract

The utility model discloses a single crystal Topcon battery low pressure diffusion air inlet pipe, and relates to the technical field of low pressure diffusion air inlet pipes, the single crystal Topcon battery low pressure diffusion air inlet pipe comprises a built-in pipe and an outer sleeve, one end of the built-in pipe is an air inlet end and is located in the middle of the outer sleeve, and the outer side line of the air inlet end extends to be closed with the outer sleeve and is a closed side; the other end of the built-in pipe is closed with the closed end of the outer sleeve, and is communicated with an inner air hole and an exhaust hole I which are laterally formed respectively; a plurality of groups of inner air holes are uniformly distributed on the built-in pipe, and a plurality of inner air holes in each group are circumferentially distributed along the central axis of the built-in pipe in a surrounding manner; a first exhaust hole, a second exhaust hole and a third exhaust hole are respectively formed in the outer sleeve, and the hole diameter in the direction from the air inlet end of the built-in pipe to the closed end is gradually increased, so that the technical problem that in the prior art, due to the fact that a single air outlet in the diffusion furnace causes different doping concentrations of silicon wafers at different positions in the pipe, the sheet resistance uniformity is poor is solved.

Description

Technical Field

[0001] This utility model relates to the field of low-pressure diffusion inlet pipe technology, specifically a low-pressure diffusion inlet pipe for monocrystalline Topcon batteries. Background Technology

[0002] Among current sustainable energy sources, solar energy is the cleanest and most promising inexhaustible energy source. Crystalline silicon solar cells have been mass-produced and applied, and their good stability and mature process flow are the foundation for their large-scale production and application. How to further improve production efficiency and reduce costs is the basic goal of research in the field of technology both domestically and internationally.

[0003] Photovoltaic solar cells can directly convert solar energy into electrical energy. Their power generation principle is based on the photovoltaic effect of semiconductor PN junctions. During the cell manufacturing process, N-type single crystals need to be diffused or deposited with boron on a silicon wafer to form a P-type thin-layer structure. A crucial step in solar cell manufacturing is the fabrication of the PN junction, often referred to as the "heart" of the cell. In the photovoltaic field, diffusion is generally used to manufacture PN junctions.

[0004] Currently, low-pressure diffusion typically uses a furnace inlet gas intake method. As the pressure decreases, the gas is rapidly drawn to the tail end, resulting in a higher sheet resistance at the furnace inlet due to insufficient gas flow. This leads to a large difference in sheet resistance between the silicon wafers at the furnace inlet and tail end, resulting in poor uniformity. Therefore, improving the gas inlet pipe method is crucial. Many methods exist, some using intermediate gas intake, others tail-end gas intake, and still others, but none are effective or may even create other problems. This invention addresses the technical problem of poor sheet resistance uniformity between the furnace inlet and tail end by proposing a low-pressure diffusion gas inlet pipe for monocrystalline Topcon cells.

[0005] The patent with patent number CN219106179U discloses a low-pressure diffusion air inlet pipe for a single crystal PERC cell proposed in this utility model, which includes: a first air inlet pipe and a second air inlet pipe. Both the first air inlet pipe and the second air inlet pipe adopt furnace inlet air intake, and the first air inlet pipe and the second air inlet pipe are symmetrically distributed in the diffusion furnace.

[0006] The purpose of this invention is to solve:

[0007] Poor sheet resistance uniformity is caused by the different doping concentrations of silicon wafers at different locations inside the diffusion furnace due to the single gas outlet.

[0008] Without changing the existing furnace structure and the length and size of the air inlet pipe, the problem of multi-point air intake in non-fixed positions is solved by modifying the structure of the air inlet pipe, and the gas is fully mixed to improve the uniformity of air intake.

[0009] To address these issues, we provide a low-pressure diffusion inlet pipe for monocrystalline Topcon cells. Utility Model Content

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-pressure diffusion inlet pipe for monocrystalline Topcon cells, thereby solving the technical problem of poor sheet resistance uniformity caused by the different doping concentrations of silicon wafers at different positions in the diffusion furnace due to a single outlet.

[0011] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0012] A low-pressure diffusion inlet pipe for a single-crystal Topcon battery includes an inner pipe and an outer pipe. One end of the inner pipe is the inlet end and is located in the middle of the outer pipe. The outer edge of the inlet end extends and closes with the outer pipe, forming the closed side.

[0013] The other end of the inner tube is closed to the outer tube with a sealed end, and the inner air hole and the exhaust hole are connected to each other on the side. Multiple sets of inner air holes are evenly distributed on the inner tube, and each set is distributed in multiple ways around the central axis of the inner tube.

[0014] The outer tube has three exhaust holes: exhaust hole one, exhaust hole two, and exhaust hole three. The diameter of the holes gradually increases from the air inlet end of the inner tube toward the closed end. The diameter of each exhaust hole is no larger than the outer diameter of the outer tube.

[0015] In a further technical solution, the internal air vents are provided in 7 groups, with at least two vents in each group, distributed on the upper and lower sides of the internal tube.

[0016] In a further technical solution, each of the exhaust holes one, two, and three is provided in a set, and each set has at least two exhaust holes, which are distributed on the upper and lower sides of the outer sleeve.

[0017] In a further technical solution, in the horizontal direction of the built-in tube, at least two sets of internal air holes are provided between the line connecting the diameters of the first set of exhaust holes and the line connecting the diameters of the second set of exhaust holes; at least two sets of internal air holes are provided between the line connecting the diameters of the second set of exhaust holes and the line connecting the diameters of the third set of exhaust holes.

[0018] In a further technical solution, the diameter of the internal air vent is 2mm, and there are 7 groups, with 2 vents in each group.

[0019] In a further technical solution, the diameter of the first exhaust hole is 5mm, the diameter of the second exhaust hole is 4mm, and the diameter of the third exhaust hole is 2mm; and there are 2 in each group.

[0020] In a further technical solution, a pressure bend is fixedly provided on the air inlet end of the built-in tube. The pressure bend is bent at a right angle and has an inverted conical tube head installed on the top. A thickened part is provided between the outer side of the inverted conical tube head and the closed side.

[0021] In a further technical solution, a rotating interface is provided on the thickened part. The rotating interface is connected to the furnace and is suitable for rotating the angle of the air inlet pipe inside the furnace.

[0022] In a further technical solution, the adjacent inner air holes are 0.5m apart; the distance between exhaust hole one and exhaust hole two is 1.3m apart; the distance between exhaust hole one and exhaust hole three is 2.6m apart; the diameter of the closed end is 16mm, the inner diameter of the inner tube is 4mm, and the inner diameter of the outer tube is 12mm.

[0023] Compared with existing technologies, it has the following advantages:

[0024] This invention utilizes multiple sets of internal air holes within the inner tube to facilitate gas transmission between the inner tube and the outer tube, ensuring even distribution of the internal air holes. Furthermore, the outer tube is equipped with exhaust holes of varying sizes (exhaust hole one, exhaust hole two, and exhaust hole three), with the largest exhaust hole at the end furthest from the closed side. This ensures that the gas entering at the inlet is dispersed layer by layer through the internal air holes and discharged at a large diameter at the tail end. This achieves both efficient airflow and uniform exhaust, ensuring thorough mixing of the incoming gas. It overcomes the limitations of single-point boron source release in existing technologies by introducing a multi-point boron source. This invention effectively solves the problem of uniform distribution of the diffused boron source within the furnace tube, improving the uniformity of boron diffusion resistance.

[0025] The reduced cross-sectional flow area of ​​the inverted conical tube head in this invention facilitates faster gas flow. The rotating interface maintains the rotational effect within the furnace, allowing for an inclined installation of the inlet pipe and enabling more diverse boron source locations. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the diffuser inlet pipe of this utility model;

[0027] Figure 2 This is a front view schematic diagram of the diffuser intake pipe of this utility model. Figure 1 ;

[0028] Figure 3 This is a front view schematic diagram of the diffuser intake pipe of this utility model. Figure 3 ;

[0029] Figure 4 This is a cross-sectional view of the diffuser intake pipe in this utility model.

[0030] In the picture:

[0031] 1. Internal tube; 11. Air inlet; 12. Internal air vent;

[0032] 2. Outer tube; 21. Vent 1; 22. Vent 2; 23. Vent 3;

[0033] 3. Closed side; 4. Closed end;

[0034] 5. Pressure bend; 51. Inverted tapered pipe head; 52. Thickened section;

[0035] 6. Rotate the interface. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] Example 1

[0038] Please see Figure 1 and 2 As shown, this is a technical solution of the present invention, specifically including a low-pressure diffusion air inlet pipe for a single crystal Topcon battery, including an inner tube 1 and an outer tube 2. One end of the inner tube 1 is an air inlet 11 and is located in the middle of the outer tube 2. The outer edge of the air inlet 11 extends and closes with the outer tube 2, forming a closed side 3.

[0039] The other end of the inner tube 1 is closed with the outer tube 2 by a closed end 4, and the inner air hole 12 and the exhaust hole 21 are respectively opened laterally and connected to each other; multiple sets of inner air holes 12 are evenly distributed on the inner tube 1, and each set is arranged in multiple circumferentially around the central axis of the inner tube 1.

[0040] The outer tube 2 is provided with exhaust hole 1 21, exhaust hole 22 and exhaust hole 3 23 respectively, and the diameter of the holes gradually increases from the air inlet end 11 of the inner tube 1 toward the closed end 4.

[0041] This invention employs a single or mixed gas, such as nitrogen, boron source, phosphorus source, or oxygen, introduced into the inlet pipe of the diffusion furnace to achieve a protective gas reaction with the silicon wafer, forming a doped layer or PN junction. From the closed side to the closed end, multiple sets of internal gas holes are arranged within the inner tube to form a gas transmission between the inner tube and the outer tube. The uniformly arranged internal gas holes ensure gas transmission. Furthermore, the outer tube has exhaust holes of varying sizes (exhaust hole one, exhaust hole two, and exhaust hole three), with exhaust hole one being the largest at the end furthest from the closed side. This ensures that the gas entering at the inlet is dispersed layer by layer through the internal gas holes and discharged at a large diameter at the tail end. This achieves both airflow and exhaust uniformity, and the introduced gas is thoroughly mixed. It overcomes the single-point release of the boron source in existing technologies by using a multi-point release method. This invention effectively solves the problem of uniform distribution of the diffusion boron source within the furnace tube, improving the uniformity of boron diffusion resistance.

[0042] like Figure 1 As shown, the inner air vent 12 is provided in 7 groups, with at least two vents in each group, distributed on the upper and lower sides of the inner tube 1. The exhaust vent 1 21, exhaust vent 22 and exhaust vent 3 23 are each provided in one group, with at least two vents in each group, distributed on the upper and lower sides of the outer tube 2.

[0043] In the horizontal direction of the built-in tube 1, at least two sets of internal air holes 12 are provided between the line connecting the diameters of the first set of exhaust holes 21 and the line connecting the diameters of the second set of exhaust holes 22; at least two sets of internal air holes 12 are provided between the line connecting the diameters of the second set of exhaust holes 22 and the line connecting the diameters of the third set of exhaust holes 23. In this embodiment, the line connecting the diameters refers to... Figure 1 The vertical connecting lines of the holes in the single-unit exhaust port one, exhaust port two, or exhaust port three are aligned and run through the corresponding horizontal positions on the internal tube. This distribution illustrates the location of exhaust port one, exhaust port two, and exhaust port three, ensuring uniform gas discharge.

[0044] Example 2

[0045] like Figure 3 As shown, another embodiment of this utility model is presented. Based on embodiment 1, in order to achieve a pressurization effect at the air inlet, a pressurizing bend 5 is fixedly installed outside the air inlet end 11 of the built-in pipe 1. The pressurizing bend 5 is bent at a right angle, and an inverted conical pipe head 51 is installed at the top. A thickened portion 52 is provided between the outer side of the inverted conical pipe head 51 and the closed side 3. The reduction of the cross-sectional flow area of ​​the inverted conical pipe head is beneficial to increasing the gas flow rate. A rotating interface 6 is provided on the thickened portion 52. The rotating interface 6 is connected to the furnace and is suitable for rotating the angle of the air inlet pipe in the furnace. The furnace structure is not shown in the figure. The rotating interface can be a flange for connecting to a controllable rotating shaft; or a slewing bearing for connecting to a fixed structure to realize the rotation of the air inlet pipe.

[0046] Example 3

[0047] like Figure 4 As shown, this is another embodiment of the present invention. Based on embodiment 1, corresponding hole sizes and distances are set to adapt to the applicant's requirements for the size of the diffusion furnace inlet pipe. The adjacent inner air holes 12 are 0.5m apart; the distance between exhaust hole one 21 and exhaust hole two 22 is 1.3m; the distance between exhaust hole one 21 and exhaust hole three 23 is 2.6m; the diameter of the closed end is 16mm, the inner diameter of the inner tube 1 is 4mm, and the inner diameter of the outer tube 2 is 12mm. Conventional diffusion furnace inlet pipes are approximately tens of centimeters to over one meter long, with the longest known diffusion furnace inlet pipe reaching 3319 mm. The dimensions of this embodiment are smaller than the longest known length. The inner air holes 12 have a diameter of 2mm and are arranged in 7 groups, with 2 holes in each group. The diameter of exhaust hole one 21 is 5mm, the diameter of exhaust hole two 22 is 4mm, and the diameter of exhaust hole three 23 is 2mm; and there are 2 holes in each group.

[0048] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A single crystal Topcon cell low pressure diffusion inlet tube characterized by, It includes built-in pipe (1) and sleeve pipe (2), one end of built-in pipe (1) is air inlet end (11) and located in the middle of sleeve pipe (2), air inlet end (11) outside line extension and sleeve pipe (2) close and is closed side (3); The other end of built-in pipe (1) is closed with sleeve pipe (2) and is closed end (4), and the lateral opening of air hole (12) and exhaust hole (21) is communicated; air hole (12) is provided with multiple groups of equal distribution on built-in pipe (1), and each group is distributed along the circumferential direction of the central axis of built-in pipe (1). Air hole (12) is provided with 7 groups, and each group is provided with at least two, which are distributed on the upper and lower sides of built-in pipe (1).

2. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 1, wherein The exhaust hole (21), exhaust hole (22) and exhaust hole (23) are provided with one group, and each group is provided with at least two, and is distributed on the upper and lower sides of sleeve pipe (2).

3. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 1, wherein In the horizontal direction of built-in pipe (1), the aperture connecting line of single group of exhaust hole (21) and the aperture connecting line of single group of exhaust hole (22) are provided with at least two groups of air holes (12); the aperture connecting line of single group of exhaust hole (22) and the aperture connecting line of single group of exhaust hole (23) are provided with at least two groups of air holes (12).

4. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 3, wherein The aperture of air hole (12) is 2mm, and 7 groups are provided, each group is provided with 2.

5. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 4, wherein, The diameter of exhaust hole (21) is 5mm, the diameter of exhaust hole (22) is 4mm, and the diameter of exhaust hole (23) is 2mm; and each group is provided with 2.

6. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 5, wherein, The air inlet end (11) of built-in pipe (1) is fixedly provided with pressurizing elbow (5) outside, pressurizing elbow (5) is bent at right angles, and inverted cone pipe head (51) is installed at the top, and thickening part (52) is provided between the outside of inverted cone pipe head (51) and closed side (3).

7. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 6, wherein, Rotary interface (6) is provided on thickening part (52), rotary interface (6) is connected with furnace, and the angle of air inlet pipe in furnace is suitable for rotation.

8. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 7, wherein, The distance between adjacent air holes (12) is 0.5m; the distance between exhaust hole (21) and exhaust hole (22) is 1.3m; the distance between exhaust hole (21) and exhaust hole (23) is 2.6m; 9. A single crystal Topcon cell low pressure diffusion inlet tube according to claim 8, wherein, The diameter of closed end is 16mm, the inner diameter of built-in pipe (1) is 4mm, and the inner diameter of sleeve pipe (2) is 12mm. ​

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