A topcon cell film layer structure and a preparation method thereof

Abstract

The application provides a TOPCon cell film layer structure and a preparation method thereof, and relates to the technical field of solar cells.The TOPCon cell film layer structure comprises a substrate, a tunneling layer is arranged on a first surface of the substrate, a first conductive type semiconductor region is arranged on the tunneling layer, a transparent conductive layer is arranged on the first conductive type semiconductor region, a plurality of first electrodes are arranged on the transparent conductive layer, a second conductive type semiconductor region is arranged on a second surface of the substrate, a second passivation film A is arranged on the second conductive type semiconductor region, a second passivation film B is arranged on the second passivation film A, and a second electrode passes through the second passivation film A and the second passivation film B and is in contact with the second conductive type semiconductor region.In the application, the transparent conductive layer is in good interface contact with the first electrode and the first conductive type semiconductor region, effective transmission of carriers is promoted, recombination of the carriers is reduced, transmission energy loss is reduced, and the photoelectric conversion efficiency of the cell is improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a TOPCon cell film structure and its preparation method. Background Technology

[0002] In the TOPCon battery, the front electrode layer passes through the second passivation film A+B layer and contacts the second type of conductive semiconductor layer, while the back electrode layer passes through the first passivation layer and contacts the first type of conductive semiconductor layer, forming a conductive path between them.

[0003] In TOPCon batteries, "recombination" is a key physical process. Recombination refers to the process by which photogenerated charge carriers (electrons and holes) return from the excited state to the ground state under the influence of various factors; that is, electrons and holes recombine and disappear. This recombination can occur in different regions of the battery, such as bulk recombination (inside the semiconductor material), surface recombination (on the semiconductor surface), and metal recombination (in the metal-semiconductor contact region).

[0004] During the operation of a solar cell, sunlight excites silicon semiconductors to generate electron-hole pairs. These charge carriers need to be effectively separated and transported to the external circuitry of the cell to generate current. However, if the charge carriers recombine during transport, it will lead to energy loss, thereby reducing the photoelectric conversion efficiency of the cell. Summary of the Invention

[0005] This invention provides a TOPCon battery film structure and its preparation method to solve the technical problem that the recombination of charge carriers during the transport process leads to energy loss and reduces the photoelectric conversion efficiency of the battery.

[0006] To address the aforementioned technical problems, this invention discloses a TOPCon battery film structure, comprising: a substrate; a tunneling layer disposed on a first surface of the substrate; a first conductivity type semiconductor region disposed on the tunneling layer; a transparent conductive layer disposed on the first conductivity type semiconductor region; a plurality of first electrodes disposed on the transparent conductive layer; a second conductivity type semiconductor region disposed on a second surface of the substrate; a second passivation film A disposed on the second conductivity type semiconductor region; a second passivation film B disposed on the second passivation film A; and a second electrode passing through the second passivation film A and the second passivation film B to contact the second conductivity type semiconductor region.

[0007] Preferably, the transparent conductive layer material includes, but is not limited to, one or more of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), fluorine-doped tin oxide (FTO), indium titanium oxide (ITiO), indium tungsten oxide (IWO), and gallium-doped zinc oxide (GZO).

[0008] Preferably, the transparent conductive layer is prepared by at least one of magnetron sputtering, chemical vapor deposition, printing, and electron beam evaporation.

[0009] A method for fabricating a TOPCon battery film structure includes: a tunneling layer forming operation on a first surface of a substrate; a first conductivity type semiconductor region forming operation on the tunneling layer; a transparent conductive layer forming operation on the first conductivity type semiconductor region; a first electrode forming operation on the transparent conductive layer; a second conductivity type semiconductor region forming operation by incorporating impurities of a second conductivity type into a second surface of the semiconductor substrate; a second passivation film A forming operation on the second conductivity type semiconductor region; a second passivation film B forming operation on the second passivation film A; and a second electrode forming operation by forming a second electrode that passes through the second passivation film A and the second passivation film B and is connected to the second conductivity type semiconductor region.

[0010] Preferably, the first electrode is prepared by using one or more methods selected from printing, electroplating, sputtering, spraying, coating, rolling, and roll printing on the transparent conductive layer of the first surface, and then sintered. The paste includes, but is not limited to, silver-coated copper paste, silver-coated nickel paste, silver-coated aluminum paste, and copper paste.

[0011] Preferably, the gate line layer of the first electrode is a single layer or multiple layers.

[0012] Preferably, the sintering temperature of the first electrode is 200-600℃.

[0013] Preferably, a second electrode is prepared on the second passivation film B on the second surface using one or more methods such as printing, electroplating, sputtering, spraying, coating, rolling, and roll printing, and then sintered.

[0014] Preferably, the gate line layer of the second electrode is a single layer or multiple layers.

[0015] Preferably, the sintering temperature of the second electrode is 600-850℃.

[0016] The technical solution of this invention has the following advantages: This invention provides a TOPCon battery film layer structure and its preparation method, relating to the field of solar cell technology. The TOPCon battery film layer structure includes a substrate, a tunneling layer disposed on a first surface of the substrate, a first conductivity type semiconductor region disposed on the tunneling layer, a transparent conductive layer disposed on the first conductivity type semiconductor region, and a plurality of first electrodes disposed on the transparent conductive layer. A second conductivity type semiconductor region is disposed on a second surface of the substrate, a second passivation film A is disposed on the second conductivity type semiconductor region, and a second passivation film B is disposed on the second passivation film A. A second electrode passes through the second passivation film A and the second passivation film B and is in contact with the second conductivity type semiconductor region. In this invention, the transparent conductive layer forms a good interfacial contact with the first electrode and the first conductivity type semiconductor region, promoting the effective transport of charge carriers, reducing charge carrier recombination, reducing transport energy loss, and improving the photoelectric conversion efficiency of the TOPCon battery.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the means particularly pointed out in the written description and the accompanying drawings.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the overall structure of a TOPCon battery film layer according to the present invention;

[0021] Figure 2 This is a schematic diagram of the drying oven structure in this invention;

[0022] Figure 3 For the present invention Figure 2 Enlarged view of the structure at point A in the middle.

[0023] In the diagram: 1. Substrate; 2. Tunneling layer; 3. First conductivity type semiconductor region; 4. Transparent conductive layer; 5. First electrode; 6. Second conductivity type semiconductor region; 7. Second passivation film A; 8. Second passivation film B; 9. Second electrode; 10. Furnace body; 11. Inlet pipe; 12. Partition plate; 13. Diversion zone; 14. Drying zone; 15. Placement platform; 16. Guide plate; 17. Support column; 18. Connecting pipe; 19. Seal 20. Shell; 21. Horizontal plate; 22. Electric push rod; 23. Fixed plate; 24. First air outlet; 25. Moving block; 26. Rotating ball; 27. Air outlet pipe; 28. Fixed ring; 29. ​​Sealing plate; 30. Sliding column; 31. Limiting block; 32. Fixed block; 33. Connecting rope; 34. Weight block; 35. Electric slide rail; 36. Slide table; 37. Guide rod; 38. Motor; 39. Screw; 40. Moving table; 51. Magnetic block. Detailed Implementation

[0024] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0025] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] This invention provides a TOPCon battery film structure, such as... Figure 1 As shown, it includes: a substrate 1, a tunneling layer 2 disposed on a first surface of the substrate 1, a first conductive type semiconductor region 3 disposed on the tunneling layer 2, a transparent conductive layer 4 disposed on the first conductive type semiconductor region 3, a plurality of first electrodes 5 disposed on the transparent conductive layer 4, a second conductive type semiconductor region 6 disposed on a second surface of the substrate 1, a second passivation film A7 disposed on the second conductive type semiconductor region 6, a second passivation film B8 disposed on the second passivation film A7, and a second electrode 9 passing through the second passivation film A7 and the second passivation film B8 to contact the second conductive type semiconductor region 6;

[0027] The transparent conductive layer 4 is made of one or more of the following materials: indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), fluorine-doped tin oxide (FTO), indium titanium oxide (ITiO), indium tungsten oxide (IWO), and gallium-doped zinc oxide (GZO);

[0028] The transparent conductive layer 4 is prepared by at least one of the following methods: magnetron sputtering, chemical vapor deposition, printing, and electron beam evaporation.

[0029] The working principle and beneficial effects of the above technical solution are as follows: The substrate 1 can be a silicon substrate 1. The first surface of the substrate 1 is sequentially provided with a tunneling layer 2, a first conductivity type semiconductor region 3, a transparent conductive layer 4 and a first electrode 5. The transparent conductive layer 4 can be made of materials with high conductivity and good light transmittance, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc aluminum oxide (AZO), fluorine-doped tin oxide (FTO), indium titanium oxide (ITiO), indium tungsten oxide (IWO), gallium-doped zinc oxide (GZO). The transparent conductive layer 4 is prepared by any one of magnetron sputtering, chemical vapor deposition, printing, or electron beam evaporation. When photogenerated charge carriers are generated inside the battery, based on the high conductivity, the charge carriers can be transversely conducted to the electrode of the battery through the transparent conductive layer 4 to form current output. The good light transmittance can ensure that the battery fully absorbs solar energy and improve the short-circuit current density of the battery.

[0030] The first electrode 5 can be made of silver-coated copper paste, which is cheaper than silver paste and can significantly reduce the production cost of the solar cell.

[0031] A second conductive type semiconductor region 6, a second passivation film A7, a second passivation film B8, and a second electrode 9 within the openings of the second passivation film A7 and the second passivation film B8 are sequentially disposed on the second surface of the substrate 1. The second electrode 9 may be made of silver paste.

[0032] In this invention, the transparent conductive layer 4 forms a good interface contact with the first electrode 5 and the first conductivity type semiconductor region 3, which promotes the effective transport of charge carriers, avoids the problem of charge carrier accumulation and recombination at the interface, reduces the energy loss during transmission, and improves the photoelectric conversion efficiency of the TOPCon cell. Furthermore, by setting the transparent conductive layer 4, direct contact between the first electrode 5 and the first conductivity type semiconductor region 3 is avoided, thereby avoiding band bending caused by the difference in work function, further promoting the effective transport of charge carriers, reducing charge carrier recombination, and preventing the first electrode 5 from contacting the first conductivity type semiconductor region 3 to generate interface states, preventing the interface states from capturing charge carriers and allowing electrons and holes to recombine at the interface.

[0033] This application also provides a method for preparing a TOPCon battery film structure, including: forming a tunneling layer 2 on a first surface of a substrate 1; forming a first conductive type semiconductor region 3 on the tunneling layer 2; forming a transparent conductive layer 4 on the first conductive type semiconductor region 3; forming a first electrode 5 on the transparent conductive layer 4; forming a second conductive type semiconductor region 6 by incorporating a second conductive type impurity into the second surface of the semiconductor substrate; forming a second passivation film A7 on the second conductive type semiconductor region 6; forming a second passivation film B8 on the second passivation film A7; forming a second passivation film B8 on the second passivation film A7; and forming a second electrode 9 that passes through the second passivation film A7 and the second passivation film B8 and is connected to the second conductive type semiconductor region 6.

[0034] The working principle and beneficial effects of the above technical solution are as follows: First, a substrate 1 is prepared, which can be a silicon substrate 1; then, a tunneling layer 2 is prepared on the first surface of the substrate 1; and a first conductive type semiconductor region 3 is prepared on the tunneling layer 2; then, a second conductive type semiconductor region 6 is prepared on the second surface of the substrate 1; and a second passivation film A7 and a second passivation film B8 are prepared on the second conductive type semiconductor region 6; then, a transparent conductive layer 4 is prepared on the first conductive type semiconductor region 3, which is made of materials with high conductivity and good light transmittance such as indium tin oxide and aluminum-doped zinc oxide; a first electrode 5 is prepared on the transparent conductive layer 4; a second electrode 9 is prepared on the second passivation film B8; TOPCon solar cells are prepared by assisted sintering using the LECO process; and the TOPCon solar cells are tested and sorted.

[0035] The transparent conductive layer 4 forms a good interface contact with the first electrode 5 and the first conductive type semiconductor region 3, which promotes the effective transport of charge carriers, avoids the problem of charge carrier accumulation and recombination at the interface, reduces the energy loss of transmission, and improves the photoelectric conversion efficiency of the TOPCon cell.

[0036] The transparent conductive layer 4 can be fabricated using magnetron sputtering or chemical vapor deposition, specifically:

[0037] When preparing the transparent conductive layer 4 using magnetron sputtering, in a vacuum environment, high-energy ions (such as argon ions) bombard the target material (such as indium tin oxide or aluminum-doped zinc oxide target), causing target atoms to sputter out and deposit on the substrate 1 to form a transparent conductive layer 4 thin film. By controlling parameters such as sputtering power, gas pressure, and temperature, the thickness, structure, and properties of the thin film can be adjusted. Magnetron sputtering allows for precise control of the film thickness and composition, producing a transparent conductive layer 4 with good uniformity and high quality. It can be prepared at relatively low temperatures, making it suitable for deposition on temperature-sensitive battery structures. It also enables large-area thin film preparation, meeting the needs of industrial production.

[0038] When preparing the transparent conductive layer 4 using chemical vapor deposition (CVD), a gaseous precursor containing elements that constitute the transparent conductive layer 4, such as indium, tin, and zinc, is introduced into the reaction chamber. A thin film of the transparent conductive layer 4 is then formed on the surface of the substrate 1 through a chemical reaction. For example, for the preparation of aluminum-doped zinc oxide films, diethylzinc and trimethylaluminum can be used as precursors, reacting and depositing on the substrate 1 in an oxygen atmosphere. CVD allows for the uniform deposition of films on substrates 1 with complex shapes, demonstrating strong adaptability to different substrates. Furthermore, by controlling parameters such as precursor flow rate, reaction temperature, and pressure, the composition and structure of the film can be precisely adjusted, which is beneficial for preparing high-quality transparent conductive layers 4.

[0039] Based on one embodiment, a first electrode 5 is prepared on the transparent conductive layer 4 of the first surface using one or more methods such as printing, electroplating, sputtering, spraying, coating, rolling, and roll printing, and then sintered. The paste includes, but is not limited to, silver-coated copper paste, silver-coated nickel paste, silver-coated aluminum paste, and copper paste.

[0040] The grid layer of the first electrode 5 is a single layer or multiple layers;

[0041] The sintering temperature of the first electrode 5 is 200-600℃;

[0042] A second electrode 9 is prepared on the second passivation film B8 on the second surface using one or more methods such as printing, electroplating, sputtering, spraying, coating, rolling, and roll printing, and then sintered.

[0043] The grid layer of the second electrode 9 is a single layer or multiple layers;

[0044] The sintering temperature of the second electrode 9 is 600-850℃.

[0045] The working principle and beneficial effects of the above technical solution are as follows: the first electrode 5 and the second electrode 9 are both made by one or more of the following methods: printing, electroplating, sputtering, spraying, coating, rolling, and roll printing. The first electrode 5 uses silver-coated copper paste, which is cheaper than silver paste and can significantly reduce the production cost of the battery cell. The sintering temperature range of the first electrode 5 is 200-600℃. The second electrode 9 uses silver paste, and the sintering temperature range of the second electrode 9 is 600-850℃.

[0046] Based on one embodiment, such as Figure 2 As shown, both the first electrode 5 and the second electrode 9 can be prepared by printing process and then sintered. To improve the preparation effect of the first electrode 5 or the second electrode 9, drying is performed before sintering. The drying is carried out in a drying furnace, which includes a furnace body 10. An air inlet pipe 11 is provided at the upper end of the furnace body 10 for introducing drying gas. A partition 12 is provided inside the furnace body 10. A flow distribution zone 13 is provided above the partition 12, and a drying zone 14 is provided below the partition 12. A vent hole is provided on the side wall of the furnace body 10, which is connected to the drying zone 14. A placement platform 15 is provided at the center of the bottom inner wall of the furnace body 10. A guide plate 16 is provided above the placement platform 15. There is a gap between the left and right sides of the guide plate 16 and the inner wall of the furnace body 10. The lower surface of the guide plate 16 is connected to the bottom wall of the furnace body 10 through a support column 17. A through hole is provided in the center of the guide plate 16. A connecting pipe 18 is placed, with its upper end connected to the lower surface of the partition plate 12. A connecting area is set at the connection position between the connecting pipe 18 and the partition plate 12. Several mounting holes are set in the connecting area, penetrating the upper and lower surfaces of the partition plate 12. A sealing shell 19 is placed above the mounting holes, with its upper end connected to a horizontal plate 20. Electric push rods 21 are set at both ends of the horizontal plate 20, and the electric push rods 21 are connected to the inner wall of the furnace body 10 through a fixing plate 22. Several first air outlets 23 are set inside the partition plate 12, penetrating the upper and lower surfaces of the partition plate 12. Several first air outlets 23 are distributed outside the connecting area. A moving block 24 is set inside the first air outlet 23. The moving block 24 is frustum-shaped, with one end connected to the lower surface of the horizontal plate 20. The diameter of the upper end of the moving block 24 is smaller than the diameter of the lower end of the moving block 24, and the diameter of the lower end of the moving block 24 is larger than the diameter of the first air outlet 23.

[0047] The working principle and beneficial effects of the above technical solution are as follows: Organic solvents and other volatiles are usually added during the preparation of silver-coated copper paste or silver paste. In order to improve the preparation quality of the first electrode 5 and the second electrode 9 and ensure the smooth progress of the sintering process, it is necessary to remove the organic solvents or other volatiles in the paste before sintering. Therefore, before the battery cell semi-finished product printed with paste enters the sintering furnace for sintering, it is necessary to use a drying furnace to dry the battery cell semi-finished product. During drying, the battery cell semi-finished product is first placed on the placement platform 15 of the drying area 14 of the furnace body 10, and then the electric push rod 21 is activated. The electric push rod 21 extends and drives the horizontal plate 20 to move downwards. The moving block 24 moves within the first air outlet 23, connecting the diversion zone 13 and the drying zone 14 through the first air outlet 23. Simultaneously, the horizontal plate 20 moves the sealing shell 19 downwards and covers the outside of the mounting hole, preventing the mounting hole from connecting with the inside of the diversion zone 13. At this time, drying gas is introduced into the diversion zone 13 of the furnace body 10 through the air inlet pipe 11. The drying gas can flow into the drying zone 14 through the first air outlet 23 and flow along the guide plate 16 towards the left and right side walls of the furnace body 10. Then, it flows downwards along the side wall of the furnace body 10 and along the lower surface of the guide plate 16, thus flowing over the semi-finished battery cells and affecting the surface of the semi-finished battery cells. The printed paste is dried, and the drying gas is finally discharged from the vent hole, realizing the flow of drying gas. After the preset drying time, the printed paste is initially dried and formed. Then, the electric push rod 21 is gradually retracted, and the horizontal plate 20 drives the moving block 24 to move. The moving block 24 gradually blocks the first vent hole 23. At the same time, the sealing shell 19 separates from the surface of the separator 12, and the drying gas can be blown directly onto the surface of the battery cell semi-finished product through the mounting hole, accelerating the drying speed of the paste and avoiding deformation of the paste caused by direct blowing during the initial drying. This improves the preparation quality of the first electrode 5 or the second electrode 9. By setting up a drying oven to print on the surface of the battery cell semi-finished product... Drying the brushed slurry helps the solvent evaporate in advance, reducing the formation of "gas channels" during sintering. This ensures the continuity of the sintered layer, improves the shear strength of the sintered joint, and makes the connection stronger after sintering. At the same time, the early evaporation of the solvent helps the sintering process, avoiding excessive extrusion of the slurry during sintering, keeping the sintered thickness uniform without significant thinning. Moreover, the drying process removes residual moisture and solvent, allowing the silver paste to reach the required temperature more quickly during sintering, accelerating the sintering process, and reducing the amount of solvent that needs to be removed during sintering, thereby reducing energy consumption during sintering.

[0048] Based on one embodiment, such as Figure 2 , Figure 3As shown, a rotating ball 25 is installed inside the mounting hole, a second air outlet is located at the center of the rotating ball 25, an air outlet pipe 26 is installed inside the second air outlet, a fixing ring 27 is installed inside the air outlet pipe 26, a sealing plate 28 is installed above the fixing ring 27, sliding holes are provided on the left and right sides of the sealing plate 28, sliding columns 29 are installed in the sliding holes, the lower end of the sliding column 29 is connected to the upper surface of the fixing ring 27, a limiting block 30 is installed at the upper end of the sliding column 29, a fixing block 31 is installed on the sealing plate 28, the fixing block 31 is made of magnetic material, a connecting rope 32 is installed on the lower surface of the sealing plate 28, one end of the connecting rope 32 is connected to the center of the lower surface of the sealing plate 28, and the other end of the connecting rope 32 extends to the bottom of the fixing ring 27 and is equipped with a weight block 33. The flow zone 13 is equipped with a drive mechanism, which includes two electric slide rails 34. The two electric slide rails 34 are symmetrically arranged on the inner wall of the furnace body 10. A slide table 35 is slidably arranged inside the electric slide rails 34. A guide rod 36 is arranged between the two slide tables 35. A motor 37 is arranged on the side wall of one of the slide tables 35. A screw 38 is arranged at the output end of the motor 37. The end of the screw 38 away from the motor 37 is rotatably connected to the side wall of the other slide table 35. A moving stage 39 is arranged on the screw 38. The moving stage 39 is threadedly connected to the screw 38 through a threaded hole. A guide hole is arranged inside the moving stage 39. The outer wall of the guide rod 36 is slidably connected to the inner wall of the guide hole. A magnetic block 40 is arranged at the lower end of the moving stage 39. The magnetic block 40 is located above the fixed block 31.

[0049] The working principle and beneficial effects of the above technical solution are as follows: After the sealing shell 19 separates from the upper surface of the partition plate 12, the electric slide rail 34 and the motor 37 are activated. The electric slide rail 34 can control the sliding table 35 to slide, thereby adjusting the position of the motor 37. The rotation of the motor 37 can drive the screw 38 to rotate. The rotation of the screw 38 drives the moving table 39 to move along the guide rod 36, thereby driving the magnetic block 40 to move. When the magnetic block 40 moves above the fixed block 31, since the fixed block 31 is made of magnetic material, preferably iron, under the action of magnetic force, the magnetic block 40 can drive the fixed block 31 to move closer to the magnetic block 40. The fixed block 31 drives the sealing plate 28 to slide upward along the sliding column 29, so that the air outlet pipe 26 is connected to the inside of the diversion area 13. The drying gas can then flow into the connecting pipe 18 through the air outlet pipe 26 and blow onto the battery half on the placement table 15. On the surface of the finished product, the drying gas can dry the printed paste. The moving stage 39 can drive the magnetic block 40 to move. When the magnetic block 40 moves, it drives the fixed block 31 to move, so that the rotating ball 25 rotates in the mounting hole, thereby adjusting the exhaust angle of the exhaust pipe 26, which facilitates all-round drying of the surface of the battery cell semi-finished product, further improving the drying effect and ensuring the performance of the first electrode 5 and the second electrode 9. When the lower surface of the sealing shell 19 contacts the upper surface of the partition plate 12, the moving stage 39 moves to the side wall of the furnace body 10. Under the action of gravity, the sealing plate 28 returns to its original position and contacts the fixed ring 27, further playing a sealing role and preventing the drying gas from flowing out from the connecting pipe 18 during the initial drying process. The weight block 33 can pull the sealing plate 28 through the connecting rope 32, so that the sealing plate 28 contacts the fixed ring 27 more smoothly, further improving the sealing effect.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a TOPCon cell film layer structure, characterized in that, The application comprises: The first electrode (5) and the second electrode (9) are prepared by printing process, and sintering is performed after printing. Drying is performed before sintering. The drying is performed in a drying furnace. The drying furnace comprises a furnace body (10). An air inlet pipe (11) is arranged at the upper end of the furnace body (10). The air inlet pipe (11) is used for introducing drying gas. A partition plate (12) is arranged in the furnace body (10). A shunt area (13) is arranged above the partition plate (12). A drying area (14) is arranged below the partition plate (12). A gas discharge hole is arranged on the side wall of the furnace body (10) and communicates with the drying area (14). A placement table (15) is arranged at the center position of the inner wall of the bottom of the furnace body (10). A flow guide plate (16) is arranged above the placement table (15). The left and right sides of the flow guide plate (16) are spaced apart from the inner wall of the furnace body (10). The lower surface of the flow guide plate (16) is connected with the bottom wall of the furnace body (10) through a support column (17). A through hole is arranged at the center of the flow guide plate (16). A communication pipe (18) is arranged at the through hole. The upper end of the communication pipe (18) is connected with the lower surface of the partition plate (12). A communication area is arranged at the position where the communication pipe (18) is connected with the partition plate (12). A plurality of mounting holes are arranged in the communication area. The mounting holes penetrate the upper and lower surfaces of the partition plate (12). A sealing shell (19) is arranged above the mounting holes. The upper end of the sealing shell (19) is connected with a horizontal plate (20). The two ends of the horizontal plate (20) are provided with electric push rods (21). The electric push rods (21) are connected with the inner wall of the furnace body (10) through a fixed plate (22). A plurality of first gas outlet holes (23) are arranged in the partition plate (12). The first gas outlet holes (23) penetrate the upper and lower surfaces of the partition plate (12). The plurality of first gas outlet holes (23) are distributed outside the communication area. A moving block (24) is arranged in the first gas outlet hole (23). The moving block (24) is in the shape of a circular truncated cone. One end of the moving block (24) is connected with the lower surface of the horizontal plate (20). The upper end diameter of the moving block (24) is smaller than the lower end diameter of the moving block (24). The lower end diameter of the moving block (24) is larger than the diameter of the first gas outlet hole (23). ​ When drying, first place the battery piece semi-finished product on the placing table (15) of the drying area (14) of the furnace body (10), then start the electric push rod (21), the electric push rod (21) extends to drive the horizontal plate (20) to move downward, the horizontal plate (20) drives the moving block (24) to move in the first air outlet hole (23), so that the shunt area (13) and the drying area (14) are communicated through the first air outlet hole (23), at the same time, the horizontal plate (20) drives the sealing shell (19) to move downward and cover the outside of the mounting hole, the mounting hole cannot be communicated with the inside of the shunt area (13), at this time, the drying gas is introduced into the shunt area (13) of the furnace body (10) through the air inlet pipe (11), the drying gas can flow into the drying area (14) through the first air outlet hole (23), and then flow along the guide plate (16) to the left and right side walls of the furnace body (10), then flow downward along the side wall of the furnace body (10) and along the lower surface of the guide plate (16), so as to flow through the battery piece semi-finished product, dry the paste printed on the surface of the battery piece semi-finished product, and then gradually retract the electric push rod (21), the horizontal plate (20) drives the moving block (24) to move, the moving block (24) gradually blocks the first air outlet hole (23), at the same time, the sealing shell (19) is separated from the surface of the partition plate (12), and the drying gas can be directly blown to the surface of the battery piece semi-finished product through the mounting hole, so as to accelerate the drying speed of the paste.

2. The method of claim 1, wherein the method further comprises: The material of the transparent conductive layer (4) comprises one or more of indium tin oxide (ITO), indium zinc oxide (IZO), zinc aluminum oxide (AZO), fluorine-doped tin oxide (FTO), indium titanium oxide (ITiO), indium tungsten oxide (IWO), and gallium-doped zinc oxide (GZO).

3. The method of claim 1, wherein the method further comprises: The transparent conductive layer (4) is prepared by at least one of a magnetron sputtering method, a chemical vapor deposition method, a printing method, and an electron beam evaporation method.

4. The method of claim 1, wherein the method further comprises: The first electrode (5) is prepared on the transparent conductive layer (4) of the first surface by using a paste by one or more of printing, electroplating, sputtering, spraying, coating, rolling, and rolling printing, and is sintered.

5. The method of claim 4, wherein the method further comprises: The grid line layer of the first electrode (5) is single-layer or multi-layer.

6. The method of claim 4, wherein the method further comprises: The sintering temperature of the first electrode (5) is 200-600 DEG C.

7. The method of claim 1, wherein the method further comprises: The second electrode (9) is prepared on the second passivation film B (8) of the second surface by using silver paste by one or more of printing, electroplating, sputtering, spraying, coating, rolling, and rolling printing, and is sintered.

8. The method of claim 7, wherein the method further comprises: The grid line layer of the second electrode (9) is single-layer or multi-layer.

9. The method of claim 7, wherein the method further comprises: The sintering temperature of the second electrode (9) is 600-850 DEG C.

10. A TOPCon cell film layer structure prepared by the method of any one of claims 1-9. The method comprises the following steps: The base (1) is provided with a tunneling layer (2) on a first surface, a first conductive type semiconductor region (3) on the tunneling layer (2), a transparent conductive layer (4) on the first conductive type semiconductor region (3), a plurality of first electrodes (5) on the transparent conductive layer (4), a second conductive type semiconductor region (6) on a second surface of the base (1), a second passivation film A (7) on the second conductive type semiconductor region (6), a second passivation film B (8) on the second passivation film A (7), and a second electrode (9) penetrating through the second passivation film A (7) and the second passivation film B (8) and contacting the second conductive type semiconductor region (6).

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