Texturing method of crystalline silicon solar cell, solar cell and flower basket

Abstract

The invention discloses a texturing method of a crystalline silicon solar cell, the solar cell and a flower basket. The texturing method comprises the following steps: providing a crystalline silicon substrate, wherein the crystalline silicon substrate comprises a first main surface and a second main surface which are opposite to each other; immersing the crystalline silicon substrate into a texturing solution, enabling the texturing solution to react with the crystalline silicon substrate, and generating bubbles on the first main surface and the second main surface of the crystalline silicon substrate; and removing bubbles attached to the first main surface of the crystalline silicon substrate, so that the size of a suede formed on the first main surface is smaller than that of a suede formed on the second main surface. According to the texturing method, the differentiated suede structure can be formed in one process groove in a one-step etching mode, and the preparation process of the differentiated suede structure is effectively simplified.

Description

Technical Field

[0001] This invention relates to a texturing method for crystalline silicon solar cells, a solar cell, and a flower basket. Background Technology

[0002] For crystalline silicon solar cells, especially crystalline silicon-perovsk tandem solar cells formed based on crystalline silicon solar cells, different main surfaces serve different purposes, resulting in varying requirements for textured surfaces. For example, in crystalline silicon-perovsk tandem solar cells, the main surfaces closer to the perovskite cell require smaller textured surfaces compared to the crystalline silicon solar cell's surface, in order to ensure the uniformity of the various film layers in the perovskite cell.

[0003] Currently, the main method for fabricating differentiated textured structures involves a mask-based, multi-stage texturing process. This involves first texturing, then placing a mask on the main surface requiring a large textured structure to protect the tip, followed by a second texturing process. This second texturing process creates a large textured structure on the masked side of the main surface at the tip, while a smaller textured structure forms on the other side. This existing texturing method requires etching solutions of varying concentrations, involves multiple process tanks, and is cumbersome and complex. Summary of the Invention

[0004] In view of this, the present invention provides a texturing method for crystalline silicon solar cells, a solar cell and a flower basket. The texturing method can form a differentiated textured surface structure in one process tank through a one-step etching process, which effectively simplifies the preparation process of the differentiated textured surface structure.

[0005] Specifically, the present invention provides the following technical solutions: This invention provides a texturing method for crystalline silicon solar cells, comprising: Step 1: Provide a crystalline silicon substrate, the crystalline silicon substrate including a first main surface and a second main surface opposite to each other; Step 2: Immerse the crystalline silicon substrate in the texturing solution, so that the texturing solution reacts with the crystalline silicon substrate and generates bubbles on both the first and second main surfaces of the crystalline silicon substrate. Step 3: Remove the air bubbles attached to the first main surface of the crystalline silicon substrate, so that the textured surface size formed on the first main surface is smaller than the textured surface size formed on the second main surface.

[0006] Optionally, in step 2, the first main surface of the crystalline silicon substrate faces the surface of the texturing solution and is parallel to the surface of the texturing solution; Step 3 includes: Step 31-1: Remove the first main surface of the crystalline silicon substrate from the texturing solution until the air bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-1: Immerse the first main surface of the crystalline silicon substrate back into the texturing solution.

[0007] Optionally, steps 31-1 and 32-1 are executed cyclically at a first preset time interval until the velvet size of the first main surface and the velvet size of the second main surface reach the preset size.

[0008] Optionally, the first preset time interval is 30s to 60s, and the number of cycles for steps 31-1 and 32-1 is 3 to 7.

[0009] Optionally, in step 2, the first main surface of the crystalline silicon substrate is parallel to the surface of the texturing solution; Step 3 includes: Step 31-2: Deliver the first fluid to the first main surface of the crystalline silicon substrate until the bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-2: Stop delivering the first fluid.

[0010] Optionally, the first fluid is an inert gas or a cleaning solution; the first main surface of the crystalline silicon substrate is purged with an inert gas or sprayed with a cleaning solution.

[0011] Optionally, the distance between the first surface of the crystalline silicon substrate and the surface of the texturing solution is 10 mm to 40 mm.

[0012] Optionally, steps 31-2 and 32-2 are executed cyclically at a second preset time interval until the velvet size of the first main surface and the velvet size of the second main surface reach the preset size.

[0013] Optionally, the second preset time interval is 30s to 60s; the number of cycles for steps 31-2 and 32-2 is 4 to 6.

[0014] Optionally, in step 2, the first main surface of the crystalline silicon substrate is perpendicular to the liquid surface of the texturing solution; Step 3 includes: Step 31-3: Deliver the second fluid to the first main surface of the crystalline silicon substrate until the bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-3: Stop supplying the second fluid.

[0015] Optionally, the second fluid is an inert gas or a cleaning liquid; the first main surface of the crystalline silicon substrate is purged with an inert gas or sprayed with a cleaning liquid.

[0016] Optionally, steps 31-3 and 32-3 are executed cyclically at a third preset time interval until the velvet size of the first main surface and the velvet size of the second main surface reach the preset size.

[0017] Optionally, the third preset time interval is 30s to 60s; the number of cycles for steps 31-3 and 32-3 is 4 to 6.

[0018] Optionally, a plurality of crystalline silicon substrates are arranged in a direction parallel to the surface of the texturing solution; the centers of the plurality of crystalline silicon substrates are located on the same straight line parallel to the surface of the texturing solution, there is a gap between two adjacent crystalline substrates, and the first main surfaces of two adjacent crystalline substrates face different directions. In step 31-3, a second fluid is supplied into the gap between the first main surfaces of two adjacent crystalline silicon substrates.

[0019] Optionally, a plurality of crystalline silicon substrates are arranged in a direction parallel to the surface of the texturing solution; the centers of the plurality of crystalline silicon substrates are located on the same straight line parallel to the surface of the texturing solution, there is a gap between two adjacent crystalline substrates, and the first main surface of all crystalline silicon substrates faces the same direction.

[0020] Optionally, the crystalline silicon solar cell is part of a perovskite crystalline silicon tandem solar cell; The perovskite solar cell in the perovskite crystalline silicon tandem solar cell is formed based on the textured structure of the first main surface of the crystalline silicon substrate.

[0021] Optionally, the texture height of the first main surface of the crystalline silicon substrate is 200nm~500nm; The texture height of the second primary surface of the crystalline silicon substrate is 2μm~3μm.

[0022] In a second aspect, embodiments of the present invention provide a solar cell, characterized in that it comprises: a crystalline silicon substrate with a double-sided textured structure prepared by the texturing method provided in the first aspect embodiment above, wherein the textured size of the first main surface of the crystalline silicon substrate is smaller than the textured size of the second main surface of the crystalline silicon substrate; preferably, the solar cell is a crystalline silicon perovskite tandem cell.

[0023] Thirdly, embodiments of the present invention provide a flower basket applied to the velvet-making method provided in the first aspect of the embodiments above, comprising: The main body of the flower basket includes a plurality of first support plates arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates are arranged opposite each other. The bearing portions are respectively located on the two main surfaces of the first support plate; The bearing portion provided on the opposing main surfaces of each pair of first support plates cooperates to support the horizontally placed crystalline silicon substrate; A driver is used to drive the support part or the flower basket body. After receiving an instruction, the driver drives the support part to move up or down along the main surface of the first support plate or drives the flower basket body to move up or down, so as to drive the crystalline silicon substrate to move up or down.

[0024] Fourthly, embodiments of the present invention provide another flower basket applied to the velvet-making method provided in the first aspect embodiment, comprising: The main body of the flower basket includes a plurality of first support plates arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates are arranged opposite each other. The bearing portions are respectively located on the two main surfaces of the first support plate; The bearing portion provided on the opposing main surfaces of each pair of first support plates cooperates to support the horizontally placed crystalline silicon substrate; Multiple first fluid output devices are arranged at intervals above the main body of the flower basket; Upon receiving an instruction, a plurality of the first fluid output devices deliver the first fluid to the first main surface of the corresponding crystalline silicon substrate.

[0025] Fifthly, embodiments of the present invention provide yet another type of flower basket applied to the velvet-making method provided in the first aspect of the embodiments, comprising: The main body of the flower basket includes two second support plates arranged opposite to each other at the top and bottom. Multiple fasteners are arranged at intervals and fixed to two opposite main surfaces of the two second support plates, and the multiple fasteners distributed on the two second support plates correspond one-to-one. A plurality of second fluid output devices are disposed on the second support plate, wherein at least one second fluid output device is disposed between two adjacent fixing members; One of the fasteners on one of the second support plates cooperates with the fastener on the other corresponding second support plate to support the vertically placed crystalline silicon substrate; Upon receiving an instruction, the second fluid output device delivers a second fluid to the first main surface of the crystalline silicon substrate to which it is located.

[0026] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects: The technical solution provided in this invention involves immersing a crystalline silicon substrate in a texturing solution, causing both the first and second main surfaces of the substrate to react with the solution and generate bubbles. The bubbles adhering to the first main surface are then removed. After the bubbles are removed, the protection of the textured structure on the first main surface is broken, allowing the texturing solution to further etch the first main surface as a whole, resulting in a smaller textured structure. Bubbles remain on the second main surface, protecting the tips of the textured structure formed thereon. The bottom of the textured structure is also etched, further increasing the size of the textured structure on the second main surface. This results in a textured structure on the first main surface being smaller than that on the second main surface, creating a textured structure with differentiated dimensions on the two main surfaces of the silicon substrate. The entire process can be achieved through a single etching step combined with bubble removal on the first main surface, enabling the formation of differentiated textured structures within a single process tank, effectively simplifying the fabrication process for these structures. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the main process of the texturing method for crystalline silicon solar cells provided in the embodiments of the present invention; Figure 2 This is a schematic cross-sectional view of a basket with a horizontally placed crystalline silicon substrate provided in an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the first type of flower basket variation corresponding to the first implementation mode of step S103 in the velvet making method provided in the embodiment of the present invention; Figure 4 This is a schematic diagram of the second type of flower basket variation corresponding to the first implementation of step S103 in the velvet-making method provided in the embodiment of the present invention; Figure 5 This is a schematic diagram of the cross-sectional changes of the flower basket corresponding to the second implementation of step S103 in the velvet-making method provided in the embodiment of the present invention; Figure 6 This is a schematic diagram of the basket change cross-section corresponding to the first placement method of the crystalline silicon substrate in the third implementation of step S103 of the texturing method provided in the embodiments of the present invention. Figure 7 This is a schematic diagram of the basket change cross-section corresponding to the second placement method of the crystalline silicon substrate in the third implementation of step S103 of the texturing method provided in the embodiment of the present invention.

[0028] The attached figures are labeled as follows: 10-Basket body; 11-First support plate; 12-Second support plate; 13-Fixing component; 20-Bearing part; 30-Process tank; 40-Texturing solution; 51-First fluid output device; 52-Second fluid output device; 60-Crystal silicon substrate; 61-First main surface; 62-Second main surface; B-Bubble. Detailed Implementation

[0029] To address the problem that the current process for preparing differentiated textured structures is relatively cumbersome and complex, this invention provides a texturing method for crystalline silicon solar cells, a solar cell, and a textured basket.

[0030] The terms "first" and "second" in this embodiment of the invention are not limitations on the number or order, but are used to distinguish different components or different positions. For example, the first fluid output device 51 and the second fluid output device 52 are used to distinguish different fluid output devices in different structures of flower baskets. Similarly, the first support plate 11 and the second support plate 12 are used to distinguish different support plates in the flower basket body 10 of different structures of flower baskets. Furthermore, the first main surface 61 and the second main surface 62 respectively represent different main surfaces of the crystalline silicon substrate 60, wherein the first main surface 61 is a main surface with a smaller textured surface, and the second main surface 62 is a main surface with a larger textured surface.

[0031] in, Figure 1 This diagram illustrates the main process flow of a texturing method for a crystalline silicon solar cell provided in an embodiment of the present invention.

[0032] This invention provides a texturing method for crystalline silicon solar cells. For example... Figure 1 As shown, the texturing method for this crystalline silicon solar cell may include the following steps: Step S101: Provide a crystalline silicon substrate 60, the crystalline silicon substrate 60 including a first main surface 61 and a second main surface 62 opposite to each other.

[0033] In this embodiment of the invention, the crystalline silicon substrate 60 can be a single-crystal silicon wafer or a polycrystalline silicon wafer doped with P-type or N-type doping elements. The P-type doping element is a trivalent element, such as boron, aluminum, gallium, indium, etc.; the N-type doping element is a pentavalent element, such as phosphorus, arsenic, antimony, or bismuth, etc. The two opposing surfaces of the crystalline silicon substrate 60 along the thickness direction are a first main surface 61 and a second main surface 62.

[0034] In this step, the crystalline silicon substrate 60 can be cleaned to remove dust, impurities, mechanical damage, etc. from the surface of the crystalline silicon substrate 60.

[0035] Step S102: Immerse the crystalline silicon substrate 60 in the texturing solution, so that the texturing solution reacts with the crystalline silicon substrate 60 and generates bubbles B on both the first main surface 61 and the second main surface 62 of the crystalline silicon substrate 60.

[0036] In this step, the texturing solution reacts with the crystalline silicon substrate 60 to form a pyramid-shaped textured surface on the first main surface 61 and the second main surface 62 of the crystalline silicon substrate 60. Gas is generated during the reaction of the texturing solution with the crystalline silicon substrate 60; for example, the reaction of an alkaline texturing solution with the crystalline silicon substrate 60 produces hydrogen gas, thereby generating bubbles B on the first main surface 61 and the second main surface 62 of the crystalline silicon substrate 60.

[0037] After the silicon substrate 60 is completely immersed in the texturing solution 40, the first main surface 61 and the second main surface 62 of the silicon substrate 60 simultaneously come into contact with the texturing solution 40. In this step S102, the etching effect of the texturing solution 40 on the first main surface 61 and the second main surface 62 of the silicon substrate 60 is basically the same. At this time, the textured surface structure formed by the first main surface 61 and the second main surface 62 of the silicon substrate 60 is basically the same.

[0038] In this step, the crystalline silicon substrate 60 can react with the texturing solution for 90 to 110 seconds before proceeding to subsequent steps, such as reacting the crystalline silicon substrate 60 with the texturing solution for 95 seconds, 100 seconds, or 105 seconds. Step S103: Remove the bubbles B attached to the first main surface 61 of the crystalline silicon substrate 60, so that the textured surface size formed on the first main surface 61 is smaller than the textured surface size formed on the second main surface 62.

[0039] Bubbles B adhering to the surface of the crystalline silicon substrate obstruct the silicon material below, hindering the contact between the texturing solution and the silicon. For locations where a pyramid structure has already formed, bubbles typically adhere to the apex of the pyramid, allowing the texturing solution to continue etching downwards to the base, increasing the pyramid's size. Based on this principle, in step S103, after the bubbles B adhering to the first main surface 61 of the crystalline silicon substrate 60 are removed, the protection of the textured structure on the first main surface 61 by the bubbles is broken, allowing the texturing solution to further etch the first main surface 61 as a whole, reducing etching of the pyramid's base and thus resulting in a smaller textured structure on the first main surface 61. However, for the second main surface 62, bubbles B adhering to the apex of the pyramid texture protect this apex from corrosion by the texturing solution, which continues to erode the base of the pyramid, increasing its size and resulting in a larger textured structure on the second main surface 62.

[0040] The preparation method provided in this invention can form a differentiated textured structure on the first and second main surfaces of a crystalline silicon substrate in one step of etching within a process tank, effectively simplifying the preparation process of the differentiated textured structure.

[0041] The crystalline silicon solar cell addressed in this embodiment of the invention can be a standalone crystalline silicon solar cell or part of a perovskite-silicon tandem solar cell. Regarding the structure where the crystalline silicon solar cell is part of a perovskite-silicon tandem solar cell, the perovskite solar cell in the perovskite-silicon tandem solar cell is generally formed based on a textured structure on the first main surface 61 of the crystalline silicon substrate 60. By using a smaller textured structure to fabricate the perovskite-silicon tandem solar cell, the uniformity of each functional layer of the perovskite solar cell can be ensured, thereby improving the photoelectric conversion efficiency of the perovskite-silicon tandem solar cell.

[0042] In this embodiment of the invention, the textured height of the first main surface 61 of the crystalline silicon substrate 60, controlled by the above technical solution, is generally 200nm~500nm; the textured height of the second main surface 62 of the crystalline silicon substrate 60 is generally 2μm~3μm. For example, the textured height of the first main surface 61 can be 200nm, 300nm, 400nm, or 500nm, etc., and the textured height of the second main surface 62 of the crystalline silicon substrate 60 can be 2μm, 2.2μm, 2.5μm, 2.8μm, or 3μm, etc. It is worth noting that the textured height generally refers to the distance between the top and bottom of the textured surface. By controlling the textured height of the first main surface 61 of the crystalline silicon substrate 60, the uniformity and consistency of each functional layer of the perovskite solar cell formed based on the first main surface 61 of the crystalline silicon substrate 60 can be ensured. By controlling the texture height of the second main surface 62 of the crystalline silicon substrate 60, the light-trapping property of the second main surface 62 of the crystalline silicon substrate 60 can be guaranteed, thereby improving the light utilization rate of the crystalline silicon solar cell.

[0043] In this embodiment of the invention, in step S102, the silicon substrate 60 can be immersed in the texturing solution either parallel to the surface of the solution or perpendicular to the surface of the solution. The specific implementation of removing bubbles attached to the first main surface 61 in step S103 differs depending on these two different immersion methods. It is understood that immersing the silicon substrate 60 parallel to the surface of the solution means that the first main surface 61 of the silicon substrate 60 is parallel to the surface of the texturing solution, and immersing the silicon substrate 60 perpendicular to the surface of the solution means that the first main surface 61 of the silicon substrate 60 is perpendicular to the surface of the texturing solution.

[0044] In the first implementation, in step S102, the first main surface 61 of the crystalline silicon substrate 60 faces the liquid surface of the texturing solution and is parallel to the liquid surface of the texturing solution.

[0045] Specifically, for the first implementation, step S103 may include steps S1031-1 and S1032-1: Step S1031-1: Remove the first main surface 61 of the crystalline silicon substrate from the texturing solution until the air bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step S1032-1: Immerse the first main surface 61 of the crystalline silicon substrate back into the texturing solution.

[0046] In this implementation, the second main surface 62 of the crystalline silicon substrate 60 is always immersed in the texturing solution to maintain reaction with the texturing solution. Steps S1031-1 and S1032-1 can be executed cyclically according to a first preset time interval until the textured surface size of the first main surface 61 and the textured surface size of the second main surface 62 reach the preset size.

[0047] The first preset time interval can be understood as the time interval between the current removal of bubbles from the first main surface 61 of the crystalline silicon substrate 60 and the next removal of bubbles from the first main surface 61 of the crystalline silicon substrate 60. Further, when step S103 includes cyclically executing steps S1031-1 and S1032-1, the first preset time interval can be 30s to 60s; the number of cycles can be 3 to 7. For example, the first preset time interval can be 30s, 40s, 50s, or 60s, and the number of cycles can be 3, 5, 6, or 7, etc.

[0048] In this implementation method, the crystalline silicon substrate 60 can be placed into a basket and the basket can be raised or lowered.

[0049] This implementation method can adopt, for example... Figure 3 and Figure 4 The flower basket shown may include: The main body of the flower basket 10 includes a plurality of first support plates 11 arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates 11 are arranged opposite each other. The bearing portions 20 are respectively disposed on the two main surfaces of the first support plate 11; The bearing portion 20 provided on the opposite main surface of each pair of first support plates 11 cooperates to support the horizontally placed crystalline silicon substrate 60; The driver (not shown in the figure) is used to drive the carrier 20 or the flower basket body 10. After receiving the instruction, the driver drives the carrier 20 to move up or down along the main surface of the first support plate 11 or drives the flower basket body 10 to move up or down, so as to drive the crystalline silicon substrate 60 to move up or down.

[0050] It is understandable that this "flower basket" is a horizontally positioned basket for placing the crystalline silicon substrate 60. The texturing solution 40 is generally contained in the process tank 30. "Horizontally positioned" refers to the orientation of the crystalline silicon substrate 60 relative to the bottom of the process tank 30 after the basket is placed there. Figure 3 and Figure 4 As shown, when the silicon substrate 60 is parallel or nearly parallel to the bottom of the process tank 30, the silicon substrate 60 is placed horizontally.

[0051] Multiple crystalline silicon substrates 60 can typically be placed in a basket. In this implementation, the polycrystalline silicon substrates 60 are placed along the same plane parallel to the bottom of the process tank 30.

[0052] Specifically, for flower basket loading type Figures 2 to 4 In the case where the silicon substrate 60 is placed horizontally in the basket (i.e., the silicon substrate 60 is placed horizontally in the basket), step S1031-1 can specifically be to lift the basket or move the supporting part 20 of the basket that carries the silicon substrate 60 upwards, so that the first main surface 61 of each silicon substrate 60 is removed from the texturing solution 40.

[0053] For example, such as Figure 3 As shown, the position of the basket body 10 within the process tank 30 remains unchanged. By lifting the support member 20 carrying the crystalline silicon substrate 60 in the basket, the first main surface 61 of the crystalline silicon substrate 60 is removed from the texturing solution 40. Alternatively, this step can also be performed as follows: Figure 4 As shown, the basket is lifted, causing the first main surface 61 of the crystalline silicon substrate 60 to be removed from the texturing solution 40.

[0054] Specifically, step S1032-1 can involve lowering the raised basket or the upward-moving support 20 so that the first main surface 61 of the crystalline silicon substrate 60 is re-immersed in the texturing solution.

[0055] It should be noted that, due to the surface tension of the texturing solution, even if the second main surface 62 of the silicon substrate 60 is not completely immersed in the texturing solution 40 due to process errors in lifting the basket or lifting the support 20, the second main surface 62 of the silicon substrate 60 will still have good contact with the texturing solution 40. This not only prevents the bubbles on the second main surface 62 of the silicon substrate 60 from bursting and protects the top of the texturing structure of the second main surface 62 of the silicon substrate 60, but also provides a relatively wide process window for step S1031-1, which is conducive to the industrialization of the technical solution provided in this embodiment of the invention.

[0056] In the second implementation, in step S102, the first main surface 61 of the crystalline silicon substrate 60 is also facing the liquid surface of the texturing solution and is parallel to the liquid surface of the texturing solution.

[0057] The second implementation method may include the following steps S1031-2 and S1032-2: Step S1031-2: A first fluid is delivered to the first main surface of the crystalline silicon substrate until the bubbles attached to the first main surface of the crystalline silicon substrate are removed.

[0058] Step S1032-2: Stop delivering the first fluid.

[0059] Understandably, in the second implementation of step S103 above, the silicon substrate 60 is always immersed in the texturing solution throughout the texturing process. In this method, the first main surface 61 of the silicon substrate 60 can face the surface of the texturing solution, i.e., the first main surface 61 is placed upwards; or it can face away from the surface of the texturing solution, i.e., the first main surface 61 is placed downwards.

[0060] The first fluid can be an inert gas, such as argon or nitrogen; or it can be a cleaning solution, such as deionized water or a low-concentration alkaline solution. The first main surface of the silicon substrate can be purged with an inert gas, or the first main surface of the silicon substrate can be sprayed with a cleaning solution. The concentration and spray volume of the cleaning solution should not affect the texturing effect of the texturing solution 40.

[0061] It is worth noting that, in order for the first fluid to remove air bubbles from the first main surface 61 of the crystalline silicon substrate 60, the distance between the first main surface 61 of the crystalline silicon substrate 60 and the surface of the texturing solution 40 needs to be controlled. Specifically, the distance between the first main surface 61 of the crystalline silicon substrate 60 and the surface of the texturing solution 40 can be 10mm to 40mm. For example, the distance between the first main surface of the crystalline silicon substrate 60 and the surface of the texturing solution 40 can be 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, or 40mm, etc.

[0062] In this implementation, steps S1031-2 and S1032-2 can be executed cyclically according to a second preset time interval until the textured surface size of the first main surface 61 and the textured surface size of the second main surface 62 reach the preset size. The second preset time interval can be understood as the time interval between the current removal of bubbles on the first main surface 61 of the crystalline silicon substrate 60 and the next removal of bubbles on the first main surface 61 of the crystalline silicon substrate 60.

[0063] In this implementation, when step S103 includes cyclically executing steps S1031-2 and S1032-2, the second preset time interval can be 30s to 60s; the number of cycles can be 4 to 6. For example, the second preset time interval can be 30s, 40s, 50s or 60s, and the number of cycles can be 4, 5 or 6.

[0064] In this implementation method, the crystalline silicon substrate 60 can also be placed in a basket.

[0065] This implementation method can adopt, for example... Figure 5 The flower basket shown may include: The main body of the flower basket 10 includes a plurality of first support plates 11 arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates 11 are arranged opposite each other. The bearing portions 20 are respectively disposed on the two main surfaces of the first support plate 11; The bearing portion 20 provided on the opposite main surface of each pair of first support plates 11 cooperates to support the horizontally placed crystalline silicon substrate 60; Multiple first fluid output devices 51 are arranged at intervals above the main body 10 of the flower basket; Upon receiving an instruction, multiple first fluid output devices 51 purge inert gas or spray cleaning fluid onto the first main surface of their corresponding crystalline silicon substrate 60.

[0066] In response to this Figure 5 The flower basket shown is immersed in the texturing solution 40 in the process tank 30, and the distance between the support part 20 and the liquid surface of the texturing solution is 10mm to 40mm. For example, the distance between the support part 20 and the liquid surface of the texturing solution is 10mm, 20mm, 30mm or 40mm, etc. By controlling the distance between the support part 20 and the liquid surface of the texturing solution, it can be effectively ensured that the first fluid output device 51 can completely remove the air bubbles on the first main surface 61 of the crystalline silicon substrate 60 by blowing inert gas or spraying cleaning fluid.

[0067] Understandably, such as Figure 5 As shown, the flower basket also includes a first fluid output device 51 disposed at the top of the flower basket. The first fluid output device 51 sprays inert gas or sprays cleaning liquid toward the first main surface 61 of the crystalline silicon substrate 60 to remove air bubbles on the upper surface of the crystalline silicon substrate 60.

[0068] The third implementation method

[0069] In this implementation, in step S102, the first main surface 61 of the crystalline silicon substrate 60 is perpendicular to the liquid surface of the texturing solution.

[0070] For the third implementation method, step S103 may include steps S1031-3 and S1032-3: Step S1031-3: A second fluid is supplied to the first main surface 61 of the crystalline silicon substrate 60 until the bubbles attached to the first main surface 61 of the crystalline silicon substrate are removed.

[0071] Step S1032-3: Stop supplying the second fluid.

[0072] The second fluid can be an inert gas, such as argon or nitrogen; or a cleaning solution, such as deionized water or a low-concentration alkaline solution. The first main surface of the silicon substrate can be purged with an inert gas, or the first main surface of the silicon substrate can be sprayed with a cleaning solution. The concentration and spray volume of the cleaning solution should not affect the texturing effect of the texturing solution 40.

[0073] Understandably, in the third implementation of step S103 above, the crystalline silicon substrate 60 is always immersed in the texturing solution throughout the texturing process.

[0074] In this implementation, steps S1031-3 and S1032-3 can be executed cyclically according to a third preset time interval until the textured surface size of the first main surface and the textured surface size of the second main surface reach the preset size. The third preset time interval can be understood as the time interval between the current removal of bubbles on the first main surface 61 of the crystalline silicon substrate 60 and the next removal of bubbles on the first main surface 61 of the crystalline silicon substrate 60.

[0075] In this implementation, when step S103 includes cyclically executing steps S1031-3 and S1032-3, the third preset time interval can be 30s to 60s; the number of cycles can be 4 to 6. For example, the second preset time interval can be 30s, 40s, 50s or 60s, and the number of cycles can be 4, 5 or 6.

[0076] In this implementation, multiple silicon substrates 60 can be arranged along a direction parallel to the surface of the texturing solution. The centers of the multiple silicon substrates 60 are located on the same straight line parallel to the surface of the texturing solution. The first main surface 61 of the silicon substrate 60 can be placed in two different ways.

[0077] The first placement method: such as Figure 6 As shown, there is a gap between two adjacent crystal substrates and the first main surfaces of the two adjacent crystal substrates face different directions.

[0078] Accordingly, in step S1031-3, a second fluid is supplied to the gap between the first main surfaces of two adjacent crystalline silicon substrates 60.

[0079] The second placement method: such as Figure 7 As shown, there is a gap between two adjacent crystal substrates 60 and the first main surface of all crystalline silicon substrates faces the same direction.

[0080] In this third implementation method, it can also be achieved by placing the crystalline silicon substrate 60 into the basket.

[0081] This implementation method can adopt, for example... Figure 6 and Figure 7 The flower basket shown may include: The main body of the flower basket 10 includes two second support plates 12 arranged opposite to each other at the top and bottom. Multiple fasteners 13 are arranged at intervals and fixed to two opposite main surfaces of two second support plates 12, and the multiple fasteners 13 distributed on the two second support plates 12 correspond one-to-one. A plurality of second fluid output devices 52 are disposed on the second support plate 12, wherein at least one second fluid output device 52 is disposed between two adjacent fixing members 13; A fastener 13 on one second support plate 12 cooperates with a fastener 13 on the other corresponding second support plate 12 to support the vertically placed crystalline silicon substrate 60; Upon receiving an instruction, the second fluid output device 52 blows inert gas or sprays cleaning fluid onto the first main surface 61 of the silicon substrate 60 that it is close to.

[0082] like Figure 6 and Figure 7 As shown, when the silicon substrate 60 is perpendicular or nearly perpendicular to the bottom of the process tank 30, the silicon substrate 60 is placed vertically.

[0083] For a first placement method in which the first main surfaces 61 of multiple crystalline silicon substrates 60 face different directions, the first main surfaces of the first crystalline silicon substrate 60 and the second crystalline silicon substrate 60 can be arranged opposite each other, the first main surfaces of the third crystalline silicon substrate 60 and the fourth crystalline silicon substrate 60 can be arranged opposite each other, the first main surfaces 61 of the fifth crystalline silicon substrate 60 and the sixth crystalline silicon substrate 60 can be arranged opposite each other, and so on; or the first main surfaces of the first crystalline silicon substrate 60 and the second crystalline silicon substrate 60 can be arranged opposite each other, the first main surfaces of the third crystalline silicon substrate 60 and the fourth crystalline silicon substrate 60 can be arranged opposite each other, the first main surfaces 61 of the fifth crystalline silicon substrate 60 and the sixth crystalline silicon substrate 60 can be arranged opposite each other, and so on.

[0084] The gap between the first silicon substrate 60 and the inner wall of the basket is defined as gap 1, the gap between the first and second silicon substrates 60 is defined as gap 2, the gap between the second and third silicon substrates 60 is defined as gap 3, and so on. At least one second fluid outlet 52 is provided between two adjacent fixing members 13, which can correspond to the odd-numbered gap or, as... Figure 6 The second fluid output device 52 is set for the even-numbered gap.

[0085] Understandably, in this basket, for each two adjacent silicon substrates 60, the second main surfaces 62 of the two silicon substrates 60 are opposite each other or the first main surfaces 61 of the two silicon substrates 60 are opposite each other, wherein the first main surfaces 61 of the silicon substrates 60 are oriented toward the gap where the second fluid output device 52 is provided.

[0086] For a second placement configuration where the first main surfaces 61 of multiple crystalline silicon substrates 60 face the same direction, at least one second fluid output device 52 is provided between two adjacent fixing members 13. This can be, for example... Figure 7 As shown, a second fluid output device 52 is provided in each gap.

[0087] For example, such as Figure 7 As shown, a second fluid output device 52 is provided in each gap. The second fluid output device 52 delivers inert gas or cleaning fluid toward the crystalline silicon substrate 60 on its left side. That is, the second fluid output device 52 is directed toward the main surface of the crystalline silicon substrate 60 located on its left side, which is the first main surface 61 of the crystalline silicon substrate 60, to remove air bubbles from cleaning the first main surface 61 of the crystalline silicon substrate 60.

[0088] In the second and third implementations of step S103 above, by delivering an inert gas or a spray cleaning liquid to the first main surface 61 of the crystalline silicon substrate 60, the liquid tension of the first main surface 61 of the crystalline silicon substrate 60 can be reduced. The lower the liquid tension, the easier it is for bubbles to overflow from the tip of the textured structure, so as to better remove the bubbles from the first main surface 61 of the crystalline silicon substrate 60.

[0089] Therefore, the technical solution provided by the present invention defoams the first main surface 61 of the crystalline silicon substrate 60, which can reduce the protective effect of bubbles on the tip of the textured structure, and thus tend to form a smaller pyramid textured structure. Subsequently, through the cyclic operation of step S103, it continues to be immersed in the texturing liquid for a period of time. During this process, the size of the textured surface on one side can be controlled and the size of the textured surface on the two main surfaces can be different.

[0090] It is worth noting that the texturing method for the above-mentioned crystalline silicon solar cells can be part of the solar cell manufacturing process. Alternatively, the texturing method for the crystalline silicon solar cells and the solar cell manufacturing process can be relatively independent processes, with the solar cell manufacturing process based on the crystalline silicon substrate prepared by the texturing method for the crystalline silicon solar cells.

[0091] Furthermore, embodiments of the present invention provide a solar cell. Specifically, the solar cell may include: a crystalline silicon substrate 60 with a double-sided textured structure prepared by the texturing method provided in any of the above embodiments, wherein the textured size of the first main surface of the crystalline silicon substrate 60 is smaller than the textured size of the second main surface of the crystalline silicon substrate 60.

[0092] Understandably, the solar cell may also include other functional layers, such as a tunneling oxide layer, a carrier collection layer, and a passivation antireflection layer. The relationship between the tunneling oxide layer, the carrier collection layer, and the passivation antireflection layer is the same as the relationship between the functional layers of existing solar cells, and will not be elaborated here.

[0093] Furthermore, the solar cell can be any type of crystalline silicon solar cell fabricated on a crystalline silicon substrate, such as TOPCon cells, PERC cells, HBC cells, TBC cells, crystalline silicon perovskite tandem cells, etc.

[0094] Preferably, the solar cell is a crystalline silicon perovskite tandem solar cell. In addition to the crystalline silicon solar cell, the crystalline silicon perovskite tandem solar cell may also include functional layers of the perovskite cell, such as a hole transport layer, a perovskite absorber layer, and an electron transport layer. These functional layers are formed on the first main surface 61 of the crystalline silicon substrate 60. The structure provided by this embodiment of the invention improves the photoelectric conversion efficiency of the crystalline silicon perovskite tandem solar cell and accelerates the production speed of crystalline silicon solar cells.

[0095] Furthermore, embodiments of the present invention also provide flower baskets with various structures applicable to the above-described velvet-making method.

[0096] Specifically, the flower basket may include, for example: Figure 5 The structure shown: The main body of the flower basket 10 includes a plurality of first support plates 11 arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates 11 are arranged opposite each other. The bearing portions 20 are respectively disposed on the two main surfaces of the first support plate 11; The bearing portion 20 provided on the opposite main surface of each pair of first support plates 11 cooperates to support the horizontally placed crystalline silicon substrate 60; The driver is used to drive the carrier 20 or the flower basket body 10. After receiving the instruction, the driver drives the carrier 20 to move up or down along the main surface of the first support plate 11 or drives the flower basket body 10 to move up or down, so as to drive the crystalline silicon substrate 60 to move up or down.

[0097] Alternatively, the flower basket may include, for example Figure 6 The structure shown: The main body of the flower basket 10 includes a plurality of first support plates 11 arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates 11 are arranged opposite each other. The bearing portions 20 are respectively disposed on the two main surfaces of the first support plate 11; The bearing portion 20 provided on the opposite main surface of each pair of first support plates 11 cooperates to support the horizontally placed crystalline silicon substrate 60; Multiple first fluid output devices 51 are arranged at intervals above the main body 10 of the flower basket; Upon receiving an instruction, multiple first fluid output devices 51 deliver first fluid to the first main surface of their corresponding crystalline silicon substrate 60.

[0098] Or the flower basket may include, for example Figure 7 The structure shown: The main body of the flower basket 10 includes two second support plates 12 arranged opposite to each other at the top and bottom. Multiple fasteners 13 are arranged at intervals and fixed to two opposite main surfaces of two second support plates 12, and the multiple fasteners 13 distributed on the two second support plates 12 correspond one-to-one. A plurality of second fluid output devices 52 are disposed on the second support plate 12, wherein at least one second fluid output device 52 is disposed between two adjacent fixing members 13; A fastener 13 on one second support plate 12 cooperates with a fastener 13 on the other corresponding second support plate 12 to support the vertically placed crystalline silicon substrate 60; Upon receiving an instruction, the second fluid output device 52 delivers a second fluid to the first main surface of the silicon substrate 60 that is adjacent to it.

[0099] The above steps are provided only to help understand the method, structure, and core ideas of this invention. Those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A texturing method for crystalline silicon solar cells, characterized in that, include: Step 1: Provide a crystalline silicon substrate, the crystalline silicon substrate including a first main surface and a second main surface opposite to each other; Step 2: Immerse the crystalline silicon substrate in the texturing solution, so that the texturing solution reacts with the crystalline silicon substrate and generates bubbles on both the first and second main surfaces of the crystalline silicon substrate; Step 3: Remove the air bubbles attached to the first main surface of the crystalline silicon substrate, so that the textured surface size formed on the first main surface is smaller than the textured surface size formed on the second main surface.

2. The texturing method for crystalline silicon solar cells according to claim 1, characterized in that, In step 2, the first main surface of the crystalline silicon substrate faces the surface of the texturing solution and is parallel to the surface of the texturing solution; step 3 includes: Step 31-1: Remove the first main surface of the crystalline silicon substrate from the texturing solution until the air bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-1: Immerse the first main surface of the crystalline silicon substrate back into the texturing solution; Optionally, steps 31-1 and 32-1 are executed cyclically at a first preset time interval until the texture size of the first main surface and the texture size of the second main surface reach a preset size; Optionally, the first preset time interval is 30s to 60s, and the number of cycles for steps 31-1 and 32-1 is 3 to 7.

3. The texturing method for crystalline silicon solar cells according to claim 1, characterized in that, In step 2, the first main surface of the crystalline silicon substrate is parallel to the liquid surface of the texturing solution; Step 3 includes: Step 31-2: A first fluid is supplied to the first main surface of the crystalline silicon substrate until the air bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-2: Stop supplying the first fluid; Optionally, the first fluid is an inert gas or a cleaning solution; the inert gas is used to purge the first main surface of the crystalline silicon substrate or the cleaning solution is used to spray the first main surface of the crystalline silicon substrate. Optionally, the distance between the first surface of the crystalline silicon substrate and the liquid surface of the texturing solution is 10 mm to 40 mm; Optionally, steps 31-2 and 32-2 are executed cyclically at a second preset time interval until the velvet size of the first main surface and the velvet size of the second main surface reach a preset size; Optionally, the second preset time interval is 30s to 60s; the number of cycles for steps 31-2 and 32-2 is 4 to 6.

4. The texturing method for crystalline silicon solar cells according to claim 1, characterized in that, In step 2, the first main surface of the crystalline silicon substrate is perpendicular to the liquid surface of the texturing solution; Step 3 includes: Step 31-3: A second fluid is supplied to the first main surface of the crystalline silicon substrate until the air bubbles attached to the first main surface of the crystalline silicon substrate are removed; Step 32-3: Stop supplying the second fluid; Optionally, the second fluid is an inert gas or a cleaning solution; the inert gas is used to purge the first main surface of the crystalline silicon substrate or the cleaning solution is used to spray the first main surface of the crystalline silicon substrate. Optionally, steps 31-3 and 32-3 are executed cyclically at a third preset time interval until the velvet size of the first main surface and the velvet size of the second main surface reach the preset size; Optionally, the third preset time interval is 30s to 60s; the number of cycles for steps 31-3 and 32-3 is 4 to 6.

5. The texturing method for crystalline silicon solar cells according to claim 4, characterized in that, A plurality of crystalline silicon substrates are arranged along a direction parallel to the surface of the texturing solution; the centers of the plurality of crystalline silicon substrates are located on the same straight line parallel to the surface of the texturing solution, and there is a gap between two adjacent crystalline substrates and the first main surfaces of two adjacent crystalline substrates face different directions; In steps 31-3, the second fluid is delivered into the gap between the first main surfaces of two adjacent crystalline silicon substrates that are disposed opposite each other.

6. The texturing method for crystalline silicon solar cells according to claim 4, characterized in that, A plurality of crystalline silicon substrates are arranged along a direction parallel to the surface of the texturing solution; the centers of the plurality of crystalline silicon substrates are located on the same straight line parallel to the surface of the texturing solution, there is a gap between two adjacent crystalline substrates, and the first main surface of all the crystalline silicon substrates faces the same direction.

7. The texturing method for crystalline silicon solar cells according to any one of claims 1 to 6, characterized in that, The crystalline silicon solar cell is a part of a perovskite crystalline silicon tandem solar cell; The perovskite solar cell in the perovskite crystalline silicon tandem solar cell is formed based on the textured structure of the first main surface of the crystalline silicon substrate.

8. The texturing method for crystalline silicon solar cells according to claim 7, characterized in that, The texture height of the first main surface of the crystalline silicon substrate is 200nm~500nm; The texture height of the second primary surface of the crystalline silicon substrate is 2μm~3μm.

9. A solar cell, characterized in that, include: The crystalline silicon substrate with a double-sided textured structure prepared by the texturing method according to any one of claims 1 to 8, wherein the textured size of the first main surface of the crystalline silicon substrate is smaller than the textured size of the second main surface of the crystalline silicon substrate; Preferably, the solar cell is a crystalline silicon perovskite tandem cell.

10. A flower basket applied to the velvet-making method according to any one of claims 1 to 8, characterized in that, include: The main body of the flower basket (10) includes a plurality of first support plates (11) arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates (11) are arranged opposite to each other; The bearing portion (20) is disposed on the two main surfaces of the first support plate (11). The support portion (20) provided on the opposite main surface of each pair of first support plates (11) cooperates to support the horizontally placed crystalline silicon substrate (60). The driver is used to drive the support part (20) or the flower basket body (10). After receiving the instruction, the driver drives the support part (20) to move up or down along the main surface of the first support plate (11) or drives the flower basket body (10) to move up or down, so as to drive the crystalline silicon substrate (60) to move up or down. Alternatively, the flower basket may include: The main body of the flower basket (10) includes a plurality of first support plates (11) arranged vertically with intervals, and the main surfaces of each pair of adjacent first support plates (11) are arranged opposite to each other; The bearing portion (20) is disposed on the two main surfaces of the first support plate (11). The support portion (20) provided on the opposite main surface of each pair of first support plates (11) cooperates to support the horizontally placed crystalline silicon substrate (60). Multiple first fluid output devices (51) are arranged at intervals above the main body of the flower basket (10). Upon receiving an instruction, a plurality of the first fluid output devices (51) deliver the first fluid to the first main surface of the corresponding crystalline silicon substrate (60); Alternatively, the flower basket may include: The main body of the flower basket (10) includes two second support plates (12) arranged opposite each other at the top and bottom. Multiple fasteners (13) are arranged at intervals and fixed to two opposite main surfaces of the two second support plates (12), and the multiple fasteners (13) distributed on the two second support plates (12) correspond one-to-one; A plurality of second fluid output devices (52) are disposed on the second support plate (12), wherein at least one second fluid output device (52) is disposed between two adjacent fixing members (13). One of the fixing members (13) on one of the second support plates (12) cooperates with the fixing member (13) on the other corresponding second support plate (12) to support the vertically placed crystalline silicon substrate (60). Upon receiving an instruction, the second fluid output device (52) delivers a second fluid to the first main surface of the crystalline silicon substrate (60) to which it is located.

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