Crystalline silicon perovskite laminated cell and preparation method thereof

Abstract

The invention discloses a crystalline silicon perovskite laminated cell and a preparation method thereof, and relates to the technical field of solar cells. The preparation method of the crystalline silicon perovskite laminated cell comprises the steps that a crystalline silicon cell is prepared, the crystalline silicon cell comprises a crystalline silicon substrate, a first main surface of the crystalline silicon substrate comprises a first central area and a first edge area surrounding the first central area, a first protective layer is continuously formed in the first edge area, and a second protective layer is formed on the second main surface of the crystalline silicon substrate; a first crystalline silicon cell function layer is formed in the first central region; the surface of the first protective layer protrudes out of the surface of the first crystalline silicon cell functional layer; and preparing a perovskite cell function layer on the surface of the first crystalline silicon cell function layer. According to the embodiment, the continuously arranged first protective layer is formed in the edge area of the first main surface of the crystalline silicon substrate to prevent the solution coated by the slit coating equipment from overflowing, so that the short circuit of the battery is avoided.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a crystalline silicon perovskite tandem solar cell and its preparation method. Background Technology

[0002] When the functional layer in a crystalline silicon perovskite tandem solar cell is prepared using slit coating, the slit coating equipment does not have high control precision at the edge of the upper surface of the cell. This can easily cause the coating solution to flow out from the edge, or even flow along the side to the lower surface and come into contact with the functional layer on the lower surface. The solvent evaporates at the flow point, forming a path from the upper surface to the lower surface, which can lead to a short circuit in the crystalline silicon perovskite tandem solar cell. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a crystalline silicon perovskite tandem solar cell and a method for its fabrication, which can prevent the overflow of the solution coated by the slit coating equipment through a protective layer, thereby avoiding the formation of a conductive pathway layer from the functional layer on the first main surface to the functional layer on the second main surface.

[0004] To achieve the above objectives, according to one aspect of the present invention, a method for fabricating a crystalline silicon perovskite tandem solar cell is provided, comprising: Step A1: Prepare a crystalline silicon cell. The crystalline silicon cell includes a crystalline silicon substrate. The first main surface of the crystalline silicon substrate includes a first central region and a first edge region surrounding the first central region. A first protective layer is continuously formed in the first edge region, and a first crystalline silicon cell functional layer is formed in the first central region. The surface of the first protective layer protrudes from the surface of the first crystalline silicon cell functional layer. Step A2: Prepare a perovskite solar cell functional layer on the surface of the first crystalline silicon solar cell functional layer.

[0005] Preferably, step A1 includes: Step A11-1: Cover the first central region with a mask layer, form a continuously disposed first protective layer in the first edge region, and remove the mask layer; Alternatively, in step A11-2, a first protective layer is prepared on the first main surface of the crystalline silicon substrate, and the portion of the first protective layer corresponding to the first central region is removed to obtain a first protective layer continuously disposed in the first edge region.

[0006] Preferably, in step A1, the second main surface of the crystalline silicon substrate includes a second central region and a second edge region surrounding the second central region, a continuously disposed second protective layer is formed in the second edge region, and a second crystalline silicon cell functional layer is formed in the second central region; the surface of the second protective layer protrudes from the surface of the second crystalline silicon cell functional layer.

[0007] Preferably, in step A1, a third protective layer is formed on the side of the crystalline silicon substrate.

[0008] Preferably, the first protective layer, the second protective layer, and the third protective layer are connected to each other.

[0009] Preferably, the first protective layer, the second protective layer, and the third protective layer all contain hydrophobic materials.

[0010] Preferably, the hydrophobic material includes at least one of the following materials: C5-18-perfluoroalkane, perfluoroacrylate polymer, polydimethylsiloxane, methyl silicone resin, and phenyl silicone resin.

[0011] Preferably, step A1 further includes: Step A12: Etch the first central region of the first main surface of the crystalline silicon substrate to a preset depth; Step A13: Prepare a first crystalline silicon cell functional layer in the first central region of the first main surface of the crystalline silicon substrate.

[0012] Preferably, step A12 further includes: texturing the first central region of the first main surface of the crystalline silicon substrate to form a large textured surface.

[0013] Preferably, step A12 further includes: on the basis of the large pile surface, re-pile the large pile surface of the first main surface to form a small pile surface; wherein the pyramid height of the small pile surface is smaller than the pyramid height of the large pile surface.

[0014] Preferably, step A2 includes: Step A21: Prepare a first carrier transport layer on the surface of the first crystalline silicon cell functional layer; Step A22: Form a perovskite layer on the outer surface of the first carrier transport layer using a wet or wet-dry hybrid method through slot coating; Step A23: Sequentially stack a second carrier transport layer and a first transparent conductive layer on the outer surface of the perovskite layer.

[0015] Preferably, step A23 further includes: An interface modification layer is formed on the outer surface of the perovskite layer before the formation of the second carrier transport layer.

[0016] Preferably, step A23 further includes: Before forming the first transparent conductive layer, a barrier layer is formed on the outer surface of the second carrier transport layer.

[0017] Preferably, the method further includes: Step A3: Form a first metal electrode on the surface of the perovskite solar cell functional layer; form a second metal electrode on the surface of the second crystalline silicon solar cell functional layer.

[0018] To achieve the above objectives, according to another aspect of the present invention, a crystalline silicon perovskite tandem solar cell is provided, comprising: A crystalline silicon substrate, wherein the first main surface of the crystalline silicon substrate includes a first central region and a first edge region surrounding the first central region; A first protective layer is continuously disposed in the first edge region; A first crystalline silicon cell functional layer is disposed in a first central region, and the surface of a first protective layer protrudes beyond the surface of the first crystalline silicon cell functional layer; and A perovskite solar cell functional layer is disposed on the surface of the first crystalline silicon solar cell functional layer.

[0019] Preferably, the width of the first protective layer is 0.5mm to 1mm.

[0020] Preferably, the second main surface of the crystalline silicon substrate includes a second central region and a second edge region surrounding the second central region. The crystalline silicon perovskite tandem solar cell further includes: a second protective layer continuously disposed in the second edge region, and a second crystalline silicon solar cell functional layer disposed in the second central region; the surface of the second protective layer protrudes from the surface of the second crystalline silicon solar cell functional layer.

[0021] Preferably, a third protective layer is also provided on the side of the crystalline silicon substrate.

[0022] Preferably, the first protective layer, the second protective layer, and the third protective layer are connected to each other.

[0023] Preferably, the thickness of the first protective layer, the second protective layer and the third protective layer is 10nm~2.0μm.

[0024] Preferably, the first central region of the crystalline silicon substrate is recessed inward relative to the first edge region.

[0025] Preferably, the second central region of the crystalline silicon substrate is recessed inward relative to the second edge region.

[0026] Preferably, the surfaces of both the first central region and the second central region are provided with a pyramid-structured velvet surface, and the pyramid height of the velvet surface in the first central region is smaller than the pyramid height of the velvet surface in the second central region.

[0027] Preferably, the crystalline silicon perovskite tandem solar cell further includes: a first metal electrode disposed on the surface of the perovskite solar cell functional layer, and a second metal electrode disposed on the surface of the second crystalline silicon solar cell functional layer.

[0028] Preferably, the first crystalline silicon cell functional layer includes a first carrier collection layer disposed on the surface of a first central region of the crystalline silicon substrate, and an interconnect layer disposed on the first carrier collection layer; the second crystalline silicon cell functional layer includes a second carrier collection layer disposed on the surface of a second central region of the crystalline silicon substrate.

[0029] Preferably, the first crystalline silicon cell functional layer includes an interconnect layer disposed on the surface of a first central region of the crystalline silicon substrate, the second central region of the crystalline silicon substrate includes a plurality of alternating first conductive regions and a plurality of second conductive regions, a first carrier collection layer is disposed on the surface of the crystalline silicon substrate corresponding to the first conductive region, and a second carrier collection layer is disposed on the surface of the crystalline silicon substrate corresponding to the second conductive region.

[0030] Preferably, the conductivity type of the first carrier collection layer is opposite to that of the second carrier collection layer.

[0031] Preferably, the conductivity type of the first carrier collection layer is the same as that of the crystalline silicon substrate.

[0032] Preferably, the first carrier collection layer is a doped layer formed by directly doping a crystalline silicon substrate, or a stacked structure of a silicon oxide layer and a doped polycrystalline silicon layer, or a stacked structure of an intrinsic silicon-containing layer containing microcrystalline silicon and / or amorphous silicon and a doped silicon-containing layer.

[0033] Preferably, the interconnect layer includes at least one of indium tin oxide, aluminum-doped zinc oxide, and indium cerium oxide.

[0034] Preferably, the second carrier collection layer comprises a stacked structure of an oxide layer and a doped polycrystalline silicon layer disposed on the surface of the second central region of the crystalline silicon substrate, or a stacked structure of an intrinsic silicon-containing layer and a doped silicon-containing layer comprising microcrystalline silicon and / or amorphous silicon.

[0035] Preferably, the perovskite solar cell functional layer includes a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a first transparent conductive layer stacked from the inside out.

[0036] Preferably, the perovskite solar cell further includes an interface modification layer disposed between the perovskite layer and the second carrier transport layer.

[0037] Preferably, the perovskite solar cell further includes a barrier layer disposed between the second carrier transport layer and the first transparent conductive layer.

[0038] Preferably, the perovskite solar cell further includes an antireflection layer disposed on the outer surface of the first transparent conductive layer.

[0039] One embodiment of the above invention has the following advantages or beneficial effects: By forming a protective layer in the first edge region of the first main surface of the crystalline silicon substrate of the crystalline silicon cell, and forming a first crystalline silicon cell functional layer in the first central region of the first surface, the surface of the first protective layer protrudes from the surface of the first crystalline silicon cell functional layer, and then a perovskite cell functional layer is prepared on the surface of the first crystalline silicon cell functional layer. The provision of the first protective layer can prevent the overflow of the perovskite cell functional layer precursor solution during the preparation of the perovskite cell functional layer, for example, the overflow of the precursor solution coated by a slot coating device, reducing the probability of the solution flowing from the first main surface to the second main surface, avoiding the formation of a conductive path layer from the functional layer on the first main surface to the functional layer on the second main surface, and eliminating the need to remove the path layer of the cell by laser or grinding, thereby improving the cell fabrication efficiency and yield.

[0040] The further effects of the aforementioned unconventional alternative methods will be explained below in conjunction with specific implementation methods. Attached Figure Description

[0041] The accompanying drawings are provided to better understand the invention and are not intended to unduly limit the scope of the invention. Wherein: Figure 1 This is a schematic diagram of a crystalline silicon perovskite tandem solar cell fabricated using a slot coating method based on existing technology. Figure 2 This is a schematic diagram illustrating leakage at the edge of a crystalline silicon perovskite tandem solar cell when prepared using a slot coating method according to existing technology. Figure 3 yes Figure 2 Enlarged view of region X in the middle; Figure 4 This is a schematic flowchart of a method for preparing a crystalline silicon perovskite tandem solar cell according to an embodiment of the present invention. Figure 5 This is a flowchart illustrating the first embodiment of step A1 according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a first method of forming a first protective layer on a first main surface according to an embodiment of the present invention; Figure 7 This is a flowchart illustrating a second embodiment of step A1 according to an embodiment of the present invention; Figure 8 This is a schematic diagram of a second method for forming a first protective layer on the first main surface according to an embodiment of the present invention; Figure 9 This is a top view of the first main surface containing the first protective layer according to an embodiment of the present invention; Figure 10 This is a schematic diagram showing a protective layer provided on a first main surface and a second main surface according to an embodiment of the present invention. Figure 11 This is a schematic diagram showing that a protective layer is provided on the first main surface, the second main surface, and the side surface according to an embodiment of the present invention. Figure 12 This is a schematic diagram of the structure of a semi-finished crystalline silicon perovskite tandem solar cell after step A12 according to an embodiment of the present invention. Figure 13 This is a schematic diagram of a structure in which an oxide protective layer is formed on the outer surface of a crystalline silicon substrate according to an embodiment of the present invention; Figure 14 This is a schematic diagram of a structure in which the portion of the oxide protective layer corresponding to the first central region of the first main surface has been removed according to an embodiment of the present invention. Figure 15 This is a schematic diagram of a structure with a small napped surface according to an embodiment of the present invention; Figure 16 This is a schematic diagram of the structure after removing the remaining oxide protective layer on the outer surface of the crystalline silicon substrate according to an embodiment of the present invention; Figure 17 This is a schematic diagram of a structure in which a first carrier collection layer and an interconnect layer are formed on the first main surface of a crystalline silicon substrate according to an embodiment of the present invention. Figure 18 This is a schematic diagram of a structure in which a second carrier collection layer and a second transparent conductive layer are formed on the second main surface of a crystalline silicon substrate according to an embodiment of the present invention. Figure 19 This is a detailed flowchart of step A2 according to an embodiment of the present invention; Figure 20 This is a schematic diagram of a structure in which a second carrier transport layer and a first transparent conductive layer are formed on the outer surface of a perovskite layer according to an embodiment of the present invention. Figure 21 This is a schematic diagram of the structure of a crystalline silicon perovskite tandem solar cell according to an embodiment of the present invention; Figure 22 This is a schematic diagram of the slit coating base according to an embodiment of the present invention; Figure 23 yes Figure 22 Enlarged schematic diagram of the Y region; Figure 24 This is a schematic diagram of a slit-coated substrate according to an embodiment of the present invention being used to prepare a perovskite layer in a crystalline silicon perovskite tandem solar cell.

[0042] Figure label: 1-Crystalline silicon perovskite tandem solar cell; 111-Crystalline silicon substrate; 1111-Large textured surface; 1112-Small textured surface; 112-Protective layer; 1121-First protective layer; 1122-Second protective layer; 1123-Third protective layer; 113-Oxide protective layer; 114-First carrier collection layer; 115-Interconnect layer; 116-Second carrier collection layer; 117-Second transparent conductive layer; 118-Second metal electrode; 119-Mask layer; 121-First carrier transport layer; 122-Perovskite layer; 123-Second carrier transport layer; 124-First transparent conductive layer; 125-First metal electrode; 2-Slit coating base; 21-Base; 211-Collection tank; 212-Placement area; 2121-Flange; 2122-Bevel; 213-Function funnel-shaped base cavity; 22-Side wall; 221-Hollow cavity; 222-Pore; 23-Recovery component; 3-Coating head. Detailed Implementation

[0043] Currently, such as Figure 1 As shown, in the process of preparing crystalline silicon perovskite tandem solar cell 1 by slit coating, the semi-finished product of crystalline silicon perovskite tandem solar cell 1 is placed in the slit coating base 2 of the slit coating equipment, and the coating head 3 of the slit coating equipment coats the front side of the crystalline silicon perovskite tandem solar cell 1 with a solution.

[0044] like Figure 2 and Figure 3 As shown, the solution coated on the surface of the semi-finished product by the coating head of the slit coating equipment can easily flow out from the edge and along the side to the back, or even to the position of the functional layer or electrode on the back, forming a through-pass layer, which leads to a short circuit in the prepared crystalline silicon perovskite tandem solar cell.

[0045] To address the short-circuit problem caused by leakage, laser or grinding methods are primarily used to remove portions of the conductive layer at the periphery of the crystalline silicon perovskite tandem solar cell, forming an edge isolation region to block the transport path of charge carriers along the conductive layer. However, these methods result in damaged layers on the cell, and the width of the edge isolation region is generally greater than 2mm, reducing the effective light-receiving area and lowering the photoelectric conversion efficiency. Furthermore, laser or grinding significantly reduces the cell fabrication efficiency and yield, impacting production capacity.

[0046] Based on the aforementioned problems in the prior art, embodiments of the present invention provide a crystalline silicon perovskite tandem solar cell and a preparation method thereof, in order to solve at least one problem existing in the prior art.

[0047] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention, including various details to aid understanding. These details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0048] It should be noted that, unless otherwise specified, the embodiments of the present invention and the technical features thereof can be combined with each other.

[0049] It should be noted that the first main surface involved in the embodiments of the present invention refers to the side of the crystalline silicon perovskite tandem solar cell 1 that faces the sunlight when it is working, and the second main surface involved in the embodiments of the present invention refers to the side of the crystalline silicon perovskite tandem solar cell 1 that faces away from the sunlight when it is working.

[0050] It should be noted that the outer surface involved in the embodiments of the present invention refers to the surface of the functional layer that is far away from the crystalline silicon substrate.

[0051] Figure 4 This is a schematic diagram of the main steps in the fabrication method of a crystalline silicon perovskite tandem solar cell 1 according to an embodiment of the present invention. Figure 4 As shown, the fabrication method of the crystalline silicon perovskite tandem solar cell 1 according to an embodiment of the present invention mainly includes the following steps: Step A1: Prepare a crystalline silicon cell. The crystalline silicon cell includes a crystalline silicon substrate 111. The first main surface of the crystalline silicon substrate 111 includes a first central region and a first edge region surrounding the first central region. A first protective layer 1121 is continuously formed in the first edge region, and a first crystalline silicon cell functional layer is formed in the first central region. The surface of the first protective layer 1121 protrudes from the surface of the first crystalline silicon cell functional layer.

[0052] The crystalline silicon cell in the crystalline silicon perovskite tandem solar cell 1 can be a tunnel oxide passivated contact solar cell (TOPCon cell), a heterojunction cell, or a back contact cell, etc.

[0053] The first edge region is set around the four edges of the first central region.

[0054] The aforementioned first protective layer 1121 being continuously disposed around the perimeter of the first main surface means that the first protective layer 1121 disposed around the perimeter of the first main surface is connected as one unit, forming a continuous structure. The continuous first protective layer 1121 facilitates the subsequent confinement of the solution applied by the slot coating device within the area enclosed by the first protective layer 1121.

[0055] The first protective layer 1121 should be made of insulating material to prevent the overflowing solution from forming a continuous conductive path together with the first protective layer 1121.

[0056] Step A2: Prepare a perovskite solar cell functional layer on the surface of the first crystalline silicon solar cell functional layer.

[0057] In the first central region enclosed by the first protective layer 112 on the first main surface of the crystalline silicon solar cell, various functional layers of the perovskite solar cell are prepared, wherein at least one functional layer of the perovskite solar cell can be prepared by a slot coating device, and the first protective layer 1121 is used to prevent the overflow of the solution coated by the slot coating device.

[0058] During the slit coating process, since the first protective layer 1121 protrudes from the surface of the first crystalline silicon cell functional layer, the solution is confined within the area enclosed by the first protective layer 1121. Furthermore, due to the surface tension of the solution, the probability of the solution overflowing through the area enclosed by the first protective layer 1121 is reduced, thereby reducing the risk of the solution flowing to the back side and causing a short circuit in the battery.

[0059] It should be noted that in perovskite solar cells, the functional layers prepared using slit coating equipment include, but are not limited to, the perovskite layer 122, and the solution blocked by the first protective layer 1121 is not limited to the perovskite precursor solution.

[0060] In one alternative embodiment, such as Figure 5 As shown, step A1 includes: Step A11-1: Cover the first central region with a mask layer 119, form a continuously disposed first protective layer 1121 in the first edge region, and remove the mask layer 119. like Figure 6 As shown, firstly, a mask layer 119 is applied to the silicon substrate 111 at a position corresponding to the first central region. The mask layer 119 can be either a removable film layer of a different material from the first protective layer 1121, or a removable mask that can be placed on the first main surface of the silicon substrate 111. Then, the first main surface of the silicon substrate 111 or its surrounding edges is cleaned with deionized water, and a protective material for forming the first protective layer 1121 is coated or deposited. After drying, a final result is obtained on the first main surface of the silicon substrate 111 as shown. Figure 9 The first protective layer 1121 shown can be prevented from forming at the position corresponding to the first central region by the shielding of the mask layer 119.

[0061] The thickness of the mask layer 119 can be 1 mm. When the mask layer 119 is a film layer of a different material from the first protective layer 1121 that is easy to remove, the mask layer 119 can be formed by spraying or deposition.

[0062] In one alternative embodiment, such as Figure 7 As shown, step A1 includes: Step A11-2: Prepare a first protective layer 1121 on the first main surface of the crystalline silicon substrate 111, and remove the portion of the first protective layer 1121 corresponding to the first central region to obtain a first protective layer 1121 continuously disposed in the first edge region.

[0063] like Figure 8 As shown, firstly, after cleaning the surface of the crystalline silicon substrate 111 with deionized water, a protective material can be coated or deposited on the entire first main surface of the crystalline silicon substrate 111. After drying, a first protective layer 1121 is prepared on the entire surface. Then, a stripping agent, strong alkali, or strong oxidizing agent can be used to remove the portion of the first protective layer 1121 corresponding to the first central region, retaining the portions around the perimeter of the first main surface of the crystalline silicon substrate 111, thereby forming a protective layer 1121 on the first edge region of the first main surface of the crystalline silicon substrate 111. Figure 9 The continuous first protective layer 1121 is shown.

[0064] Optionally, the removal agent can be selected according to the protective material of the first protective layer 1121 and the degree of influence of the removal agent on the crystalline silicon substrate 111. For example, for the protective layer formed by C5-18-perfluoroalkane and perfluoroacrylate polymers, a special stripping agent specifically for fluorine-containing coatings can be used.

[0065] It is understood that, in order to avoid corrosion of the crystalline silicon substrate 111 when the above-mentioned removal agent removes the portion of the first protective layer 1121 corresponding to the first central region, thereby affecting the surface flatness and mechanical strength of the crystalline silicon substrate 111, the first protective layer 1121 is preferably prepared by the method of step A11-1.

[0066] In step A1, the crystalline silicon substrate 111 can be an N-type silicon wafer or a P-type silicon wafer.

[0067] Furthermore, such as Figure 10 As shown, in step A1 above, while forming the first protective layer 1121 on the first main surface, a second protective layer 1122 can also be formed on the periphery of the second main surface of the crystalline silicon cell.

[0068] Specifically, step A1 may further include: the second main surface of the crystalline silicon substrate 111 includes a second central region and a second edge region surrounding the second central region; while a first protective layer 1121 is formed on the first main surface of the crystalline silicon substrate 111, a continuously disposed second protective layer 1122 is formed on the second edge region of the second main surface of the crystalline silicon substrate 111, and the preparation method can be the same; and a second crystalline silicon cell functional layer is formed in the second central region; wherein the surface of the second protective layer 1122 protrudes from the surface of the second crystalline silicon cell functional layer. By providing the second protective layer 1122 on the second main surface of the crystalline silicon substrate 111, the solution flowing to the second main surface can be prevented from flowing inward into the functional film layer of the second central region, further preventing short circuits in the solar cell.

[0069] Preferably, such as Figure 11 As shown, a third protective layer 1123 may also be formed on the side of the crystalline silicon substrate 111. The first protective layer 1121 on the first main surface of the crystalline silicon substrate 111, the second protective layer 1122 on the second main surface, and the third protective layer 1123 on the side are connected.

[0070] Specifically, a protective material for forming the third protective layer 1123 can be applied to the four sides of the crystalline silicon substrate 111 by spraying or spin coating, thereby forming the third protective layer 1123 on all four sides of the crystalline silicon substrate 111. Since the sides are areas connecting the edges of the first and second main surfaces, by providing a connecting protective layer on the first main surface, the second main surface, and the sides of the crystalline silicon substrate 111, it is possible to prevent solution from seeping from the sides of the crystalline silicon substrate 111, avoid the solution overflowing from the first central region of the first main surface from forming a continuous pathway layer from the first main surface to the second main surface, and further prevent short circuits in the solar cell.

[0071] For ease of description, unless otherwise specified, the first protective layer 1121, the second protective layer 1122 and the third protective layer 1123 will be collectively referred to as protective layer 112.

[0072] In one possible embodiment, the protective layer 112 is formed of a protective material containing a hydrophobic material. By using a protective material containing a hydrophobic material to form the protective layer 112, the overflowing solution can be prevented from wetting the surface of the crystalline silicon substrate 111, so that the solution does not adhere to the surface of the crystalline silicon substrate 111 and a channel layer is not formed on the surface of the crystalline silicon substrate 111.

[0073] Preferably, the hydrophobic material includes at least one of the following materials: C5-18-perfluoroalkane, perfluoroacrylate polymers, polydimethylsiloxane, methyl silicone resin, phenyl silicone resin, etc., but is not limited thereto. It is understood that any protective material that can form a protective layer 112 on the surface of the crystalline silicon substrate 111 without damaging the crystalline silicon perovskite tandem solar cell 1 may be used, and no specific limitation is made herein.

[0074] More preferably, the hydrophobic material can be a mixture of 98% by mass of C5-18-perfluoroalkane and 2% by mass of perfluoroacrylate polymers. C5-18-perfluoroalkane is a colorless and transparent liquid at room temperature, odorless and non-toxic, exhibiting good human safety, thermal stability, insulation, and environmental safety. During the subsequent fabrication of the crystalline silicon perovskite tandem solar cell 1, it maintains stable performance even under high-temperature environments. Furthermore, C5-18-perfluoroalkane has low surface tension, allowing it to penetrate into the tiny gaps on the surface of the crystalline silicon substrate 111, forming a dense protective layer 112. This prevents the solution applied by the slot coating equipment from seeping into the crystalline silicon substrate 111 through the protective layer 112. C5-18-perfluoroalkane is insoluble in water, so even if multiple etching and washing processes are required during subsequent fabrication, no obvious marks will be left on the surface of the protective layer 112. Perfluoroacrylate polymers possess excellent water and oil repellency and high weather resistance, maintaining stability for extended periods during the operation of the crystalline silicon perovskite tandem solar cell 1, and are not prone to aging or degradation. Therefore, the protective layer 112 formed by C5-18-perfluoroalkane and perfluoroacrylate polymers exhibits good hydrophobicity, insulation, and weather resistance, with high adhesion. It can form a dense film layer at the edges of the first main surface, the second main surface, and the sides, making it difficult for solutions to penetrate. It also exhibits fast thermal conductivity, high light transmittance, and does not affect the light-receiving area of ​​the crystalline silicon perovskite tandem solar cell 1.

[0075] In step A11-1 or step A11-2 above, the drying conditions for drying the protective material to form the protective layer 112 may include: drying at 50℃~80℃ for 5min~10min, or drying at room temperature for 15min~40min. As an example, the above drying conditions may include: drying temperatures of 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, or 80℃, etc., and drying times of 5min, 6min, 7min, 7.5min, 8min, 9min, or 10min, etc. As another example, the above drying conditions may include: drying temperature at room temperature, and drying time of 15min, 20min, 25min, 30min, 35min, or 40min, etc.

[0076] The thickness of the protective layer 112 can be from 10 nm to 2.0 μm. Preferably, the thickness of the protective layer 112 can be 10 nm, 50 nm, 100 nm, 500 nm, 1.0 μm, 1.5 μm, or 2.0 μm, etc. The protective layer 112 is relatively thin and does not affect the heat dissipation capacity of the battery.

[0077] In one alternative embodiment, such as Figure 5 or Figure 7 As shown, step A1 also includes the following steps A12 to A13: Step A12: Etch the first central region of the first main surface of the silicon substrate 111 to a predetermined depth; Furthermore, after etching, step A12 also includes: texturing the first central region of the first main surface of the silicon substrate 111 to form a large textured surface 1111. The silicon substrate 111, to which the first protective layer 1121 is formed, is cleaned with deionized water. Avoiding the first protective layer 1121 formed on the first main surface of the silicon substrate 111, the first central region enclosed by the first protective layer 1121 is etched and texturized. If the second protective layer 1122 is formed at the edge of the second main surface, the second central region of the second main surface is simultaneously etched and texturized to form a layer as shown in the image. Figure 12 The structure shown. By etching to deepen the first central region, it is possible to further prevent the solution coated by the slit coating device from overflowing from the first central region on the first main surface, and due to the height difference between the second protective layer 1122 and the second crystalline silicon cell functional layer, the solution overflowing to the second main surface is less likely to flow into the second central region.

[0078] The height of the pyramid in the large-textured 1111 is 500nm to 3μm. As an example, the pyramid height of the large-textured 1111 can be 200nm, 500nm, 750nm, 1μm, 1.5μm, 2.0μm, 2.5μm or 3μm, etc.

[0079] Furthermore, step A12 further includes: on the basis of the large pile surface 1111, the large pile surface 1111 of the first main surface is re-piled to form a small pile surface 1112; wherein the pyramid height of the small pile surface 1112 is smaller than the pyramid height of the large pile surface 1111.

[0080] Specifically, such as Figure 13 As shown, based on the formation of the large textured surface 1111, the crystalline silicon substrate 111 can be subjected to high-temperature oxidation to form an oxide protective layer 113 on the entire outer surface of the crystalline silicon substrate 111. The oxide protective layer 113 mainly comprises silicon dioxide; as Figure 14As shown, acid etching is used to remove the portion of the oxide protective layer 113 corresponding to the first central region on the first main surface. Under the protection of the oxide protective layer 113, other parts of the outer surface of the silicon substrate 111 will not be etched; as Figure 15 As shown, the large pile surface 1111 of the first main surface is re-piled to form a small pile surface 1112 with a pyramid height smaller than that of the large pile surface 1111; finally, as... Figure 16 As shown, the remaining oxide protective layer 113 on the outer surface of the crystalline silicon substrate 111 is removed.

[0081] Optionally, before re-texturing, the first main surface can be polished at the position corresponding to the first central region to facilitate the preparation of a more uniform small pile surface 1112 of the pyramid on a flat polished surface.

[0082] Among them, the small velvet 1112 has a micro-nano structure. The height of the pyramid of the small velvet 1112 is 100nm~500nm.

[0083] By re-texturing the first main surface corresponding to the first central region, a small textured surface 1112 with a lower pyramid height is formed, which can improve the light-harvesting ability and enhance the light-trapping effect. Furthermore, the pyramid size in the micro-nano-scale small textured surface 1112 is more uniform and the drop is smaller, which reduces structural defects and optimizes the photoelectric conversion efficiency of the crystalline silicon perovskite tandem solar cell 1.

[0084] Alternatively, alkaline etching or acid etching can be used for etching and texturing.

[0085] Step A13: Prepare the first crystalline silicon cell functional layer in the first central region of the first main surface of the crystalline silicon substrate 111.

[0086] Depending on the type of crystalline silicon cell in the crystalline silicon perovskite tandem solar cell 1, the functional layer of the first crystalline silicon cell may also be different.

[0087] In one alternative embodiment, such as Figure 17 As shown, when the crystalline silicon cell is not a back-contact cell, step A13 may include the following steps A131 to A132: Step A131: Deposit a first carrier collection layer 114 in the first central region of the first main surface of the crystalline silicon substrate 111; The first carrier collection layer 114 can be used to collect electrons or holes.

[0088] The first carrier collecting layer 114 can be a single film layer or a stack containing multiple functional layers. Specifically, when the first carrier collecting layer 114 is used to collect electrons, it can include an N-type doped layer, or a stack of a tunneling oxide layer and an N-type doped polycrystalline silicon layer, or a stack of an intrinsic amorphous silicon layer and an N-type doped silicon thin film, etc.; when the first carrier collecting layer 114 is used to collect holes, it can include a P-type doped layer, or a P-type doped diffusion layer, or a stack of intrinsic amorphous silicon and a P-type doped amorphous silicon layer, etc. Here, N-type doping refers to doping with a pentavalent element, in which the majority carriers are electrons; P-type doping refers to doping with a trivalent element, in which the majority carriers are holes.

[0089] As an example, when the crystalline silicon cell is a heterojunction cell, the first carrier collection layer 114 can be a stack of an intrinsic amorphous silicon layer and an N-type doped silicon-containing thin film. By setting an intrinsic amorphous silicon layer at a position corresponding to the first central region on the first main surface of the crystalline silicon substrate 111, the surface defects of the crystalline silicon substrate 111 are passivated by the hydrogen atoms contained therein, thereby reducing carrier recombination loss.

[0090] Step A132: An interconnect layer 115 is formed on the outer surface of the first carrier collection layer 114; The interconnect layer 115 may be made of at least one of the following: indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), and indium cerium oxide (ICO), and is not limited thereto.

[0091] Optionally, the thickness of the interconnect layer 115 can be 1nm to 20nm. As an example, the thickness of the interconnect layer 115 can be 1nm, 5nm, 7.5nm, 10nm, 15nm or 20nm, etc.

[0092] By setting the interconnect layer 115, for the crystalline silicon perovskite tandem solar cell 1 containing the nip perovskite structure, holes from the perovskite solar cell and electrons from the crystalline silicon solar cell can be efficiently and with low loss recombination in the interconnect layer 115, and for the crystalline silicon perovskite tandem solar cell 1 containing the pin perovskite structure, electrons from the perovskite solar cell and holes from the crystalline silicon solar cell can be efficiently and with low loss recombination in the interconnect layer 115, thereby realizing the internal series connection of the perovskite solar cell and the crystalline silicon solar cell.

[0093] It should be noted that regardless of whether the crystalline silicon cell is a heterojunction cell, a TOPCon cell, a back-contact cell, or any other type of crystalline silicon solar cell, the functional film layer closest to the perovskite cell in the first central region of the first main surface of the crystalline silicon cell is the interconnect layer 115.

[0094] Furthermore, step A13 also includes: preparing a second crystalline silicon cell functional layer in the second central region of the second main surface of the crystalline silicon substrate 111.

[0095] Specifically, step A13 may include depositing a second carrier collection layer 116 in the second central region of the second surface.

[0096] The second carrier collecting layer 116 and the first carrier collecting layer 114 collect different types of carriers. Specifically, when the first carrier collecting layer 114 is used to collect electrons, the second carrier collecting layer 116 is used to collect holes; when the first carrier collecting layer 114 is used to collect holes, the second carrier collecting layer 116 is used to collect electrons.

[0097] When the second carrier collection layer 116 is used to collect electrons, it may include an N-type doped layer, or a stack of a tunneling oxide layer and an N-type doped polycrystalline silicon layer, or a stack of an intrinsic amorphous silicon layer and an N-type doped silicon thin film, etc.; when the second carrier collection layer 116 is used to collect holes, it may include a P-type doped layer, or a P-type doped diffusion layer, or a stack of an intrinsic amorphous silicon layer and a P-type doped amorphous silicon layer, etc.

[0098] As an example, when the crystalline silicon cell is a heterojunction cell and the first carrier collection layer 114 is used to collect electrons, the second carrier collection layer 116 can be a stack of intrinsic amorphous silicon layer and P-type doped amorphous silicon layer.

[0099] Optionally, in addition to the second carrier collection layer 116, other film layers can be provided in the functional layer of the second crystalline silicon cell, such as... Figure 18 As shown, a second transparent conductive layer 117 with a thickness of 100 nm is disposed on the outer surface of the second carrier collection layer 116 to collect transversely transported carriers and reduce series resistance.

[0100] In one alternative embodiment, such as Figure 19 As shown, step A2 above includes: Step A21: Prepare a first carrier transport layer 121 on the surface of the first crystalline silicon cell functional layer; The first carrier transport layer 121 can be either a hole transport layer or an electron transport layer. When the first carrier collection layer 114 of the crystalline silicon cell is used to collect electrons, the first carrier transport layer 121 is a hole transport layer; when the first carrier collection layer 114 of the crystalline silicon cell is used to collect holes, the first carrier transport layer 121 is an electron transport layer.

[0101] The hole transport layer may include, but is not limited to, nickel oxide, nickel oxide and a mixture of self-assembled monolayers (SAMs) materials. The SAMs materials are generally mixtures of multiple materials, or may be hybrid monolayers (Co-SAMs).

[0102] Specifically, the first carrier transport layer 121 can be disposed outside the interconnect layer 115 disposed on the first main surface of the crystalline silicon cell.

[0103] Step A22: A perovskite layer 122 is formed on the outer surface of the first carrier transport layer 121 by means of wet or dry-wet mixed coating. The preparation of the perovskite layer 122 by wet slit coating mainly includes: preparing a perovskite precursor solution in advance, coating the perovskite precursor solution onto the outside of the first carrier transport layer 121 by slit coating equipment, and forming the perovskite layer 122 by vacuum crystallization.

[0104] The preparation of the perovskite layer 122 using a wet-dry mixing method via slot coating mainly includes: First, depositing inorganic salt onto the outer side of the first carrier transport layer 121 using vacuum evaporation to form an inorganic salt film; then, using slot coating equipment, coating an organic salt solution onto the outer side of the deposited inorganic salt film, allowing the organic salt to react with the inorganic salt to generate perovskite, thus forming the perovskite layer 122. The inorganic salt and organic salt solution are determined by the perovskite composition of the perovskite layer 122. For example, when preparing a perovskite layer 122 containing FACsPbI3 perovskite molecules, the inorganic salt can be PbI2, and the organic salt solution can be an isopropanol solution of formamidinium iodide (FAI) and cesium iodide (CsI).

[0105] It is understandable that during the preparation of the perovskite layer 122 by slit coating, whether a wet or dry-wet mixing method is used, the coated solution may flow down along the edge and side of the first main surface to the second main surface, causing a short circuit after the solution dries and forms a through conductive path. However, by forming a protruding first protective layer 1121 around the perimeter of the first main surface of the crystalline silicon cell, it can work synergistically with the surface tension of the solution to form a capillary confinement effect, confining the solution as much as possible within the first central area enclosed by the first protective layer 1121, thus reducing the probability of the solution overflowing to the second main surface.

[0106] Step A23, as follows Figure 20 As shown, a second carrier transport layer 123 and a first transparent conductive layer 124 are sequentially stacked on the outer surface of the perovskite layer 122.

[0107] The second carrier transport layer 123 can be an electron transport layer or a hole transport layer, which is the opposite of the majority carrier type in the first carrier transport layer 121. That is, when the first carrier transport layer 121 is a hole transport layer, the second carrier transport layer 123 is an electron transport layer; when the first carrier transport layer 121 is an electron transport layer, the second carrier transport layer 123 is a hole transport layer.

[0108] Specifically, when the first carrier transport layer 121 of the perovskite solar cell is a hole transport layer and the second carrier transport layer 123 is an electron transport layer, the perovskite solar cell is a nip perovskite structure; when the first carrier transport layer 121 is an electron transport layer and the second carrier transport layer 123 is a hole transport layer, the perovskite solar cell is a pin perovskite structure.

[0109] Optionally, step A23 may further include: forming an interface modification layer on the outer surface of the perovskite layer 122 before forming the second carrier transport layer 123. The interface modification layer can be made of materials such as 1,3-diaminopropane dihydroiodide (PDADI), but is not limited to these.

[0110] Specifically, the solution used to prepare the interface modification layer can be coated onto the outer surface of the perovskite layer 122 by spin coating or slot coating, and then dried to obtain the interface modification layer. For example, the solution used to prepare the interface modification layer can be an ethanol solution of PDADI.

[0111] By forming an interface modification layer between the perovskite layer 122 and the second carrier transport layer 123, direct contact between the perovskite layer 122 and the second carrier transport layer 123 can be prevented, avoiding the problem of chemical degradation at the interface. Furthermore, the interface modification layer passivates interface defects and improves the photoelectric conversion efficiency of the battery.

[0112] Optionally, step A23 may further include: forming a barrier layer on the outer surface of the second carrier transport layer 123 before forming the first transparent conductive layer 124. The barrier layer may include, but is not limited to, tin oxide, titanium dioxide, aluminum oxide, etc.

[0113] A barrier layer can be formed on the outer surface of the second carrier transport layer 123 using atomic layer deposition (ALD).

[0114] By providing a barrier layer between the second carrier transport layer 123 and the first transparent conductive layer 124, interface defects can be effectively passivated, and the migration of harmful ions that may form recombination centers between the second carrier transport layer 123 and the first transparent conductive layer 124 can be blocked.

[0115] In one alternative embodiment, such as Figure 21 As shown, the above method further includes: step A3, forming a first metal electrode 125 on the surface of the perovskite solar cell functional layer; forming a second metal electrode 118 on the surface of the second crystalline silicon solar cell functional layer, to obtain... Figure 21 The crystalline silicon perovskite tandem solar cell 1 shown uses a first metal electrode 125 and a second metal electrode 118 to collect and extract current.

[0116] The first metal electrode 125 and the second metal electrode 118 can be prepared by vapor deposition.

[0117] Optionally, after the first metal electrode 125 is formed, the above method further includes forming an anti-reflection layer on the outside of the first transparent conductive layer 124.

[0118] The antireflective layer can be prepared by vapor deposition. The antireflective layer may include, but is not limited to, magnesium fluoride, silicon oxide, and aluminum oxide.

[0119] By setting an antireflection layer on the first main surface of the perovskite tandem solar cell, light reflection can be effectively reduced, the effective light absorption of the cell can be increased, and the short-circuit current density of the cell can be improved.

[0120] According to the method for fabricating a crystalline silicon perovskite tandem solar cell 1 according to an embodiment of the present invention, a first protective layer 1121 protruding from the surface of a first crystalline silicon cell functional layer formed in the first edge region of the first main surface of the crystalline silicon cell is formed, and various functional layers of the perovskite solar cell are fabricated on the first crystalline silicon cell functional layer on the first main surface of the crystalline silicon cell. This allows the first protective layer 1121 to block the overflow of the solution coated by the slit coating equipment, reducing the probability of it flowing from the first main surface to the second main surface, avoiding the formation of a conductive path layer from the functional layer of the first main surface to the functional layer of the second main surface, and eliminating the need to remove the path layer of the cell by laser or grinding, thereby improving the cell fabrication efficiency and yield.

[0121] In addition, a second protective layer 1122 and a third protective layer 1123 can be formed on the second edge region and the side of the second main surface of the crystalline silicon cell, respectively. The first protective layer 1121, the second protective layer 1122 and the third protective layer 1123 are connected to form a whole, which can effectively protect the edge of the first main surface, the edge of the second main surface and the side of the crystalline silicon perovskite tandem cell 1. Even if the solution on the first main surface overflows to the side or the second main surface, the possibility of it wetting the surface of the crystalline silicon substrate 111 and the functional layer of the second central region of the second main surface will be reduced due to the protection of the above-mentioned protective layers.

[0122] Furthermore, the aforementioned protective layer is formed using a protective material containing hydrophobic material. If the solution coated by the slot coating equipment overflows, it will be affected by gravity and quickly slide off the surface of the hydrophobic protective layer, further preventing the formation of a passage layer at the edge of the first main surface, the edge of the second main surface, and the side surface.

[0123] like Figure 21 As shown, the crystalline silicon perovskite tandem solar cell 1 of this embodiment of the invention includes: The crystalline silicon substrate 111 has a first main surface including a first central region and a first edge region surrounding the first central region; A first protective layer 1121 is continuously disposed in the first edge region; A first crystalline silicon cell functional layer is disposed in the first central region, and the surface of the first protective layer 1121 protrudes from the surface of the first crystalline silicon cell functional layer; and A perovskite solar cell functional layer is disposed on the surface of the first crystalline silicon solar cell functional layer.

[0124] It is understood that the tandem solar cell provided in the embodiments of the present invention includes two parts: a crystalline silicon solar cell and a perovskite solar cell.

[0125] The first protective layer 1121 can be made of an insulating and hydrophobic protective material. On the one hand, it can avoid the formation of conductive paths between the first protective layer 1121 and the functional layers of the crystalline silicon cell or the perovskite cell. On the other hand, it can avoid the problem of the solution coated by the slit coating equipment wetting the first protective layer 1121, penetrating into the cell, and forming a pathway layer on the surface of the first protective layer 1121. The solution can quickly roll off the hydrophobic first protective layer 1121 and is not easy to condense or stay on its surface.

[0126] Optionally, the width of the first protective layer 1121 can be 0.5mm to 1mm. As an example, the width of the first protective layer 1121 can be 0.5mm, 0.6mm, 0.75mm, 0.8mm, 0.9mm or 1mm, etc.

[0127] The thickness of the first protective layer 1121 can be from 10 nm to 2.0 μm. As an example, the thickness of the first protective layer 1121 can be 10 nm, 50 nm, 100 nm, 300 nm, 750 nm, 1 μm, 1.5 μm or 2.0 μm, etc.

[0128] By setting the width and thickness of the first protective layer 1121 within a suitable range, the first protective layer 1121 can not only block the overflow of the solution, but also avoid affecting the effective light-receiving area of ​​the battery. Furthermore, it can avoid problems such as the first protective layer 1121 being too thick affecting the mechanical properties of the battery, or the first protective layer 1121 being too thin failing to achieve a good protective effect.

[0129] The perovskite solar cell is disposed in the first central region enclosed by the first protective layer 1121 on the first main surface of the crystalline silicon solar cell, wherein at least one functional layer of the perovskite solar cell is prepared by a slot coating device; the first protective layer 1121 is used to prevent the overflow of the solution coated by the slot coating device.

[0130] In an optional embodiment of the present invention, the crystalline silicon substrate 111 may be an N-type silicon wafer or a P-type silicon wafer. Preferably, the crystalline silicon substrate 111 may be an N-type silicon wafer.

[0131] In this embodiment of the invention, the second main surface of the crystalline silicon substrate 111 may include a second central region and a second edge region surrounding the second central region. The crystalline silicon perovskite tandem solar cell 1 may further include: a second protective layer 1122 continuously disposed in the second edge region, and a second crystalline silicon solar cell functional layer disposed in the second central region; the surface of the second protective layer 1122 protrudes from the surface of the second crystalline silicon solar cell functional layer. By disposing of the second protective layer 1122 at the edge of the second surface of the crystalline silicon substrate 111, the solution flowing to the second main surface can be prevented from flowing inward to the second crystalline silicon solar cell functional film layer, further preventing short circuits in the solar cell.

[0132] In this embodiment of the invention, a third protective layer 1123 may be provided on the side of the crystalline silicon substrate 111. The third protective layer 1123 may be provided on all four sides of the crystalline silicon substrate 111. The first protective layer 1121, the second protective layer 1122, and the third protective layer 1123 may be interconnected. By providing the interconnected first protective layer 1121, the second protective layer 1122, and the third protective layer 1123, it is possible to prevent the solution from wetting the side of the crystalline silicon substrate 111, avoid the solution overflowing from the first central region of the first main surface from forming a continuous pathway layer from the first main surface to the second main surface, and further prevent short circuits in the battery.

[0133] In this embodiment of the invention, the first central region of the crystalline silicon substrate 111 may be recessed inward relative to the first edge region. Correspondingly, the second central region of the crystalline silicon substrate 111 may also be recessed inward relative to the second edge region.

[0134] In this embodiment of the invention, the surfaces of both the first central region and the second central region can be provided with a pyramid-structured textured surface. The pyramid height of the textured surface in the first central region can be smaller than the pyramid height of the textured surface in the second central region. The pyramid height of the textured surface in the second central region can be 500 nm to 3 μm, and the pyramid height of the textured surface in the first central region can be 100 nm to 500 nm.

[0135] Furthermore, in this embodiment of the invention, the crystalline silicon perovskite tandem solar cell 1 may further include: a first metal electrode 125 disposed on the surface of the perovskite solar cell functional layer, and a second metal electrode 118 disposed on the surface of the second crystalline silicon solar cell functional layer. The surface of the first metal electrode 125 may be substantially flush with the surface of the first protective layer 1121, and the surface of the second metal electrode 128 may be substantially flush with the surface of the second protective layer 1122.

[0136] In this embodiment of the invention, the specific composition of the first crystalline silicon cell functional layer and the second crystalline silicon cell functional layer may differ depending on the type of crystalline silicon cell.

[0137] When the crystalline silicon cell is a back-contact cell, the first crystalline silicon cell functional layer may include an interconnect layer 115 disposed on the surface of the first central region of the crystalline silicon substrate 111, the second central region of the crystalline silicon substrate 111 includes a plurality of alternating first conductive regions and a plurality of second conductive regions, and the second crystalline silicon cell functional layer includes a first carrier collection layer 114 disposed on the surface of the crystalline silicon substrate corresponding to the first conductive region, and a second carrier collection layer 116 disposed on the surface of the crystalline silicon substrate corresponding to the second conductive region.

[0138] When the crystalline silicon cell is not a back contact cell, the first crystalline silicon cell functional layer includes a first carrier collection layer 114 disposed on the surface of the first central region of the crystalline silicon substrate 111, and an interconnect layer 115 disposed on the first carrier collection layer 114; the second crystalline silicon cell functional layer includes a second carrier collection layer 116 disposed on the surface of the second central region of the crystalline silicon substrate 111.

[0139] In this embodiment of the invention, the conductivity type of the first carrier collection layer 114 is opposite to that of the second carrier collection layer 116.

[0140] Furthermore, the conductivity type of the first carrier collection layer 114 can be opposite to that of the crystalline silicon substrate 111, thereby forming a pn junction between the first carrier collection layer 114 and the crystalline silicon substrate 111.

[0141] The crystalline silicon substrate 111 can be N-type, and correspondingly, the first carrier collection layer 114 is P-type, and the second carrier collection layer 116 is N-type.

[0142] Both the first carrier collection layer 114 and the second carrier collection layer 116 can be doped layers formed by directly doping the crystalline silicon substrate 111, or they can be a stacked structure of silicon oxide layer and doped polycrystalline silicon layer, or they can be a stacked structure of intrinsic silicon-containing layer and doped silicon-containing layer containing microcrystalline silicon and / or amorphous silicon.

[0143] In this embodiment of the invention, the specific structural combinations of the first carrier collection layer 114 and the second carrier collection layer 116 can be as follows: five different combinations.

[0144] The first method

[0145] The first carrier collection layer 114 is a doped layer formed by directly doping the first central region of the crystalline silicon substrate 111, and the second carrier collection layer 116 is a stacked structure including an oxide layer and a doped polycrystalline silicon layer disposed on the surface of the second central region of the crystalline silicon substrate 111.

[0146] In this first approach, the second crystalline silicon cell functional layer also includes a passivation layer disposed on the second carrier collection layer 116, such as a stacked structure of aluminum oxide and silicon nitride.

[0147] The second method

[0148] The first carrier collection layer 114 and the second carrier collection layer 116 are both disposed in the second central region of the crystalline silicon substrate 111.

[0149] The first carrier collection layer 114 is a doped layer formed by directly doping the first conductive region of the second central region of the crystalline silicon substrate 111, and the second carrier collection layer 116 is a stacked structure including an oxide layer and a doped polycrystalline silicon layer disposed on the surface of the second conductive region of the second central region of the crystalline silicon substrate 111.

[0150] The third method

[0151] The first carrier collection layer 114 and the second carrier collection layer 116 are both disposed in the second central region of the crystalline silicon substrate 111.

[0152] The first carrier collection layer 114 is a stacked structure comprising an oxide layer and a doped polysilicon layer disposed on the surface of a first conductive region in the second central region of the crystalline silicon substrate 111. The second carrier collection layer 116 is a stacked structure comprising an oxide layer and a doped polysilicon layer disposed on the surface of a second conductive region in the second central region of the crystalline silicon substrate 111.

[0153] In the second and third methods described above, the second crystalline silicon cell functional layer also includes a passivation layer disposed on the first carrier collection layer 114 and the second carrier collection layer 116, such as a stacked structure of aluminum oxide and silicon nitride.

[0154] Furthermore, in the first, second, and third methods described above, the second metal electrode 118 passes through the passivation layer and forms an ohmic contact with the first carrier collection layer 114 and / or the second carrier collection layer 116.

[0155] The fourth method

[0156] The first carrier collection layer 114 and the second carrier collection layer 116 are both disposed in the second central region of the crystalline silicon substrate 111.

[0157] The first carrier collection layer 114 is a stacked structure comprising an intrinsic silicon-containing layer and a doped silicon-containing layer, disposed on the surface of the second conductive region in the second central region of the crystalline silicon substrate 111. The second carrier collection layer 116 is a stacked structure comprising an oxide layer and a doped polycrystalline silicon layer, disposed on the surface of the second conductive region in the second central region of the crystalline silicon substrate 111.

[0158] In this fourth approach, the second crystalline silicon cell functional layer further includes a second transparent conductive layer 117, such as an indium tin oxide layer, disposed on the first carrier collection layer 114 and the second carrier collection layer 116.

[0159] The fifth method

[0160] The first carrier collection layer 114 is a stacked structure of an intrinsic silicon-containing layer and a doped silicon-containing layer, comprising microcrystalline silicon and / or amorphous silicon, disposed on the surface of the first central region of the crystalline silicon substrate 111. The second carrier collection layer 116 is a stacked structure of an intrinsic silicon-containing layer and a doped silicon-containing layer, comprising microcrystalline silicon and / or amorphous silicon, disposed on the surface of the second central region of the crystalline silicon substrate 111.

[0161] In this fifth approach, the second crystalline silicon cell functional layer further includes a second transparent conductive layer 117, such as an indium tin oxide layer, disposed on the second carrier collection layer 116.

[0162] Furthermore, in the fourth and fifth methods described above, the second metal electrode 118 forms an ohmic contact with the second transparent conductive layer 117, and current is transmitted through the transparent conductive layer.

[0163] In this embodiment of the invention, the interconnect layer 115 can be at least one of indium tin oxide, aluminum-doped zinc oxide, and indium cerium oxide.

[0164] In an optional embodiment of the present invention, the perovskite solar cell includes a first carrier transport layer 121, a perovskite layer 122, a second carrier transport layer 123, and a first transparent conductive layer 124 stacked from the inside out.

[0165] In this process, the majority carriers in the first carrier transport layer 121 and the second carrier transport layer 123 are of opposite types. For example, when the first carrier transport layer 121 is a hole transport layer for transporting holes, the second carrier transport layer 123 is an electron transport layer for transporting electrons; when the first carrier transport layer 121 is an electron transport layer for transporting electrons, the second carrier transport layer 123 is a hole transport layer for transporting holes.

[0166] The type of the first carrier transport layer 121 can be determined according to the type of majority carriers in the first carrier collection layer 114 disposed on the first main surface of the crystalline silicon cell. That is, when the first carrier collection layer 114 of the crystalline silicon cell is used to collect electrons, the first carrier transport layer 121 is a hole transport layer; when the first carrier collection layer 114 of the crystalline silicon cell is used to collect holes, the first carrier transport layer 121 is an electron transport layer.

[0167] The perovskite layer 122 can be prepared by a wet method or a dry-wet mixture method.

[0168] Preferably, the perovskite solar cell further includes an interface modification layer disposed between the perovskite layer 122 and the second carrier transport layer 123. By providing the interface modification layer, direct contact between the perovskite layer 122 and the second carrier transport layer 123 can be prevented, avoiding chemical degradation at the interface. Furthermore, the interface modification layer passivates interface defects, thereby improving the photoelectric conversion efficiency of the solar cell.

[0169] Preferably, the perovskite solar cell further includes a barrier layer disposed between the second carrier transport layer 123 and the first transparent conductive layer 124. By providing the barrier layer, interface defects can be effectively passivated, and the migration of harmful ions that may form recombination centers between the second carrier transport layer 123 and the first transparent conductive layer 124 can be blocked.

[0170] Preferably, the perovskite solar cell further includes an antireflection layer disposed on the outer surface of the first transparent conductive layer 124. By providing the antireflection layer, light reflection can be effectively reduced, the effective light absorption of the cell can be increased, and the short-circuit current density of the cell can be improved.

[0171] According to an embodiment of the present invention, the crystalline silicon perovskite tandem solar cell 1 has a first protective layer 1121 protruding from the first main surface of the crystalline silicon substrate 111, which is disposed on the periphery of the first main surface of the crystalline silicon substrate 111. The first crystalline silicon solar cell functional layer and the perovskite solar cell functional layer are disposed in the area enclosed by the first protective layer 1121 on the first main surface of the crystalline silicon solar cell. The first protective layer 1121 can block the overflow of the solution coated by the slot coating equipment, reduce the probability of it flowing from the first main surface to the second main surface, avoid the formation of a conductive path layer from the functional layer on the first main surface to the functional layer on the second main surface, and eliminate the need to remove the path layer by laser or grinding, thereby improving the cell fabrication efficiency and yield.

[0172] This invention also provides a slit-coating substrate 2, which can be applied to the fabrication method of the crystalline silicon perovskite tandem solar cell 1 in this invention. For example... Figure 22 As shown, the slit coating base 2 may include a base 21.

[0173] like Figure 22 and Figure 23 As shown, the base 21 includes a placement area 212 and a liquid collection tank 211 arranged around the perimeter of the placement area 212. The placement area 212 is used to place the semi-finished product of the crystalline silicon perovskite tandem solar cell 1.

[0174] The edge of the placement area 212 is provided with an upwardly protruding flange 2121, which abuts against the edge of the semi-finished product to prevent the coating solution applied to the semi-finished product from flowing to the placement area 212 or the side of the semi-finished product facing the placement area 212.

[0175] In the above-mentioned process of preparing the crystalline silicon perovskite tandem solar cell 1, the semi-finished product of the crystalline silicon perovskite tandem solar cell 1 is placed on the base 21, and the flange 2121 abuts against the semi-finished product to prevent the coating solution from flowing to the functional layer of the second main surface of the semi-finished product, so as to avoid the problem of short circuit caused by the coating solution contacting the functional layer of the second main surface.

[0176] The orthographic projection of the flange 2121 falls into the orthographic projection of the liquid collection tank 211, thereby causing the coating solution flowing down from the first main surface of the semi-finished product to fall into the liquid collection tank 211.

[0177] In the case where the crystalline silicon perovskite tandem solar cell 1 placed in the base 21 is a crystalline silicon perovskite tandem solar cell 1 in the embodiment of the present invention, the protective layers 112 are provided on the four edges of the first main surface, the four edges of the second main surface, and the side surface, respectively. The flange 2121 can abut against the second protective layer 1122 on the second main surface of the crystalline silicon perovskite tandem solar cell 1. Preferably, the abutment position is the edge of the second protective layer 1122 near the center of the second main surface, thereby preventing the coating solution flowing to the second main surface from flowing to the second central region.

[0178] The side of the aforementioned placement area 212 is an inclined surface 2122 that faces the aforementioned collection tank 211, which allows the coating solution blocked by the flange 2121 to quickly roll down along the inclined surface 2122 into the collection tank 211 below.

[0179] The aforementioned collection tank 211 can be used to collect the coating solution that overflows from the semi-finished product. The shape of the groove cross-section can be semi-circular, elliptical, funnel-shaped, or rectangular, etc., and can be set according to the actual situation.

[0180] In an optional embodiment of the present invention, the base 21 further includes a funnel-shaped base cavity 213 located below the placement area 212 and a drain port communicating with the funnel-shaped base cavity 213. The collection tank 211 communicates with the funnel-shaped base cavity 213, allowing the coating solution collected in the collection tank 211 to flow into the funnel-shaped base cavity 213. The funnel-shaped base cavity 213 is used to further collect the coating solution in the collection tank 211 and discharge it through the drain port.

[0181] Furthermore, the aforementioned drain port can be connected to the recycling component 23, which is used to recycle the coating solution collected in the cavity 213 of the funnel-shaped base, thereby realizing the recycling of the coating solution, reducing waste, and lowering costs.

[0182] Preferably, the bottom wall of the funnel-shaped base cavity 213 is inclined toward the drain port, so that the coating solution can flow to the drain port and then into the recovery component 23, thus preventing the coating solution from remaining in the funnel-shaped base cavity 213.

[0183] In an optional embodiment of the present invention, the slit coating base 2 further includes: a sidewall 22 having a hollow cavity 221 disposed around the base 21, and an air hole 222 disposed on the sidewall 22 and communicating with the hollow cavity 221. The side of the base 21 is provided with at least one communicating hole communicating with the funnel-shaped base cavity 213, and the hollow cavity 221 of the sidewall 22 communicates with the funnel-shaped base cavity 213 through the communicating hole.

[0184] The aforementioned vent 222 is connected to an external air extraction device to extract the gas in the aforementioned funnel-shaped base cavity 213, thereby creating a negative pressure in the aforementioned funnel-shaped base cavity 213. This promotes the accelerated downward flow of the coating solution overflowing to the side of the crystalline silicon perovskite tandem solar cell 1, and the rapid flow of the coating solution in the liquid collection tank 211 into the funnel-shaped base cavity 213.

[0185] Preferably, the sidewall 22 and the base 21 are an integral structure to enhance the mechanical strength of the slit coating base 2.

[0186] It should be noted that the slit coating substrate 2 of this embodiment is not only applicable to the crystalline silicon perovskite tandem solar cell 1 of this embodiment, but also applicable to crystalline silicon perovskite tandem solar cells 1 with other structures, and is not limited thereto. The slit coating substrate 2 of this embodiment is applicable to the crystalline silicon perovskite tandem solar cell 1 containing functional layers that can be prepared by coating a solution using a slit coating device, and is particularly applicable to the perovskite layer 122, interface modification layer, etc.

[0187] The principle of use of the slit coating base 2 in this embodiment of the invention: Taking the preparation of the perovskite layer 122 of the perovskite cell in the crystalline silicon perovskite tandem solar cell 1 using a slit coating device including the slit coating base 2 as an example, a protective layer 112 is provided on the periphery of the first main surface, the periphery of the second main surface, and the side surface of the crystalline silicon perovskite tandem solar cell 1. Figure 22 , Figure 23 and Figure 24As shown, the semi-finished product of the crystalline silicon perovskite tandem solar cell 1, which is to be coated with the perovskite precursor solution, is placed in the placement area 212 within the slot coating base 2. The second main surface of the semi-finished product faces the base 21 of the slot coating base 2, and the sidewall 22 of the slot coating base 2 surrounds the side of the semi-finished product. A liquid collection tank 211 is provided around the perimeter of the base 21. When the external air extraction device connected to the air hole 222 is activated, after the coating head 3 of the slit coating equipment coats the perovskite precursor solution onto the first central area of ​​the first main surface of the semi-finished product, the first protective layer 1121 around the perimeter of the first main surface of the semi-finished product prevents the perovskite precursor solution from overflowing. If the perovskite precursor solution overflows and flows down the side of the semi-finished product toward the base 21, a negative pressure is formed inside the funnel-shaped base cavity 213 due to the operation of the external air extraction device. The airflow between the side of the semi-finished product and the side wall 22 of the slit coating base 2 accelerates and flows toward the lower outlet of the liquid collection tank 211, causing the perovskite precursor solution on the side to slide down faster. After the perovskite precursor solution flows along the side to the second main surface, it is blocked by the flange 2121 that abuts against the second protective layer 1122 of the second main surface and slides down the inclined surface 2122 on the side of the placement area 212 into the liquid collection tank 211. As a negative pressure is formed inside the hollow cavity 221 and the funnel-shaped base cavity 213, the perovskite precursor solution in the collection tank 211 is accelerated to fall into the funnel-shaped base cavity 213, and flows along the bottom wall of the funnel-shaped base cavity 213 inclined towards the drain port to the drain port, and then flows into the recovery component 23 through the drain port, so as to realize the recycling and reuse of the perovskite precursor solution.

[0188] According to the embodiment of the present invention, the slit coating base 2 has a liquid collection tank 211 provided around the periphery of the placement area 212 of the base 21, and an upwardly protruding flange 2121 provided at the edge of the placement area 212. The flange 2121 abuts against the semi-finished product of the crystalline silicon perovskite tandem solar cell 1, which can prevent the coating solution from flowing down to the functional layer of the second main surface of the semi-finished product, thus avoiding the problem of short circuit of the battery caused by the contact between the coating solution and the functional layer of the second main surface. The coating solution can flow down into the liquid collection tank 211, thus preventing the coating solution from accumulating at the edge corner of the base 21.

[0189] By setting a flange 2121 that abuts against the second main surface of the semi-finished product, the probability of the coating solution flowing through the abutment position to the position where the functional layer is set on the second main surface can be reduced; by setting the side of the placement area 212 as an inclined surface 2122 that is inclined towards the liquid collection tank 211, the solution blocked by the flange 2121 can be accelerated to slide down the inclined surface 2122 into the liquid collection tank 211.

[0190] By setting the base 21 and side wall 22 as a cavity structure, the funnel-shaped base cavity 213 is connected to the hollow cavity 221 of the side wall 22, and the side wall 22 is provided with an air hole 222 that is connected to the hollow cavity 221. The air hole 222 is connected to an external air extraction device, which can create a negative pressure inside the funnel-shaped base cavity 213, causing the solution flowing to the side of the semi-finished product to slide down faster, and the solution inside the liquid collection tank 211 to fall into the funnel-shaped base cavity 213 faster.

[0191] By providing a drain port in the base 21 that communicates with the funnel-shaped base cavity 213, and by tilting the bottom wall of the funnel-shaped base cavity 213 toward the drain port, the coating solution falling into the funnel-shaped base cavity 213 can quickly flow into the recovery component 23 through the drain port, thereby realizing the recycling and reuse of the coating solution and reducing resource consumption.

[0192] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a crystalline silicon perovskite tandem solar cell, characterized in that, include: Step A1: Prepare a crystalline silicon cell. The crystalline silicon cell includes a crystalline silicon substrate (111). The first main surface of the crystalline silicon substrate (111) includes a first central region and a first edge region surrounding the first central region. A first protective layer (1121) is continuously formed in the first edge region, and a first crystalline silicon cell functional layer is formed in the first central region. The surface of the first protective layer (1121) protrudes from the surface of the first crystalline silicon cell functional layer. Step A2: Prepare a perovskite solar cell functional layer on the surface of the first crystalline silicon solar cell functional layer.

2. The method for preparing a crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, Step A1 includes: Step A11-1: Cover the first central region with a mask layer (119), form a continuously disposed first protective layer (1121) in the first edge region, and remove the mask layer (119). or, Step A11-2: Prepare a first protective layer (1121) on the first main surface of the crystalline silicon substrate (111), remove the portion of the first protective layer (1121) corresponding to the first central region, and obtain a first protective layer (1121) continuously disposed on the first edge region.

3. The method for preparing a crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, In step A1, the second main surface of the crystalline silicon substrate (111) includes a second central region and a second edge region surrounding the second central region. A second protective layer (1122) is continuously formed in the second edge region, and a second crystalline silicon cell functional layer is formed in the second central region. The surface of the second protective layer (1122) protrudes from the surface of the second crystalline silicon cell functional layer. Preferably, in step A1, a third protective layer (1123) is formed on the side of the crystalline silicon substrate (111). Preferably, the first protective layer (1121), the second protective layer (1122), and the third protective layer (1123) are connected to each other; Preferably, the first protective layer (1121), the second protective layer (1122), and the third protective layer (1123) all contain hydrophobic materials; Preferably, the hydrophobic material includes at least one of the following materials: C5-18-perfluoroalkane, perfluoroacrylate polymer, polydimethylsiloxane, methyl silicone resin, and phenyl silicone resin.

4. The method for preparing a crystalline silicon perovskite tandem solar cell according to claim 2 or 3, characterized in that, Step A1 also includes: Step A12: Etch the first central region of the first main surface of the crystalline silicon substrate (111) to a predetermined depth; Step A13: Prepare the first crystalline silicon cell functional layer in the first central region of the first main surface of the crystalline silicon substrate (111); Preferably, step A12 further includes: texturing the first central region of the first main surface of the crystalline silicon substrate (111) to form a large textured surface (1111). Preferably, step A12 further includes: on the basis of the large pile surface (1111), the large pile surface (1111) of the first main surface is re-piled to form a small pile surface (1112); wherein the pyramid height of the small pile surface (1112) is smaller than the pyramid height of the large pile surface (1111).

5. The method for preparing a crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, Step A2 includes: Step A21: Prepare a first carrier transport layer (121) on the surface of the first crystalline silicon cell functional layer. Step A22: A perovskite layer (122) is formed on the outer surface of the first carrier transport layer (121) by means of wet or dry-wet mixed coating. Step A23: A second carrier transport layer (123) and a first transparent conductive layer (124) are sequentially stacked on the outer surface of the perovskite layer (122). Preferably, step A23 further includes: Before forming the second carrier transport layer (123), an interface modification layer is formed on the outer surface of the perovskite layer (122); Preferably, step A23 further includes: Before forming the first transparent conductive layer (124), a barrier layer is formed on the outer surface of the second carrier transport layer (123); Preferably, the method further includes: Step A3: A first metal electrode (125) is formed on the surface of the perovskite solar cell functional layer; a second metal electrode (118) is formed on the surface of the second crystalline silicon solar cell functional layer.

6. A crystalline silicon perovskite tandem solar cell, characterized in that, include: A crystalline silicon substrate (111), wherein the first main surface of the crystalline silicon substrate (111) includes a first central region and a first edge region surrounding the first central region; A first protective layer (1121) is continuously disposed in the first edge region. A first crystalline silicon cell functional layer is provided in the first central region, and the surface of the first protective layer (1121) protrudes from the surface of the first crystalline silicon cell functional layer. as well as A perovskite cell functional layer is disposed on the surface of the first crystalline silicon cell functional layer.

7. The crystalline silicon perovskite tandem solar cell according to claim 6, characterized in that, The width of the first protective layer (1121) is 0.5mm~1mm; Preferably, the second main surface of the crystalline silicon substrate (111) includes a second central region and a second edge region surrounding the second central region. The crystalline silicon perovskite tandem solar cell further includes: a second protective layer (1122) continuously disposed in the second edge region, and a second crystalline silicon solar cell functional layer disposed in the second central region; the surface of the second protective layer (1122) protrudes from the surface of the second crystalline silicon solar cell functional layer. Preferably, a third protective layer (1123) is also provided on the side of the crystalline silicon substrate (111). Preferably, the first protective layer (1121), the second protective layer (1122), and the third protective layer (1123) are connected to each other; Preferably, the thickness of the first protective layer (1121), the second protective layer (1122), and the third protective layer (1123) is 10 nm to 2.0 μm.

8. The crystalline silicon perovskite tandem solar cell according to claim 7, characterized in that, The first central region of the crystalline silicon substrate (111) is recessed inward relative to the first edge region; Preferably, the second central region of the crystalline silicon substrate (111) is recessed inward relative to the second edge region; Preferably, the surfaces of both the first central region and the second central region are provided with a pyramid-structured velvet surface, wherein the pyramid height of the velvet surface in the first central region is smaller than the pyramid height of the velvet surface in the second central region. Preferably, the crystalline silicon perovskite tandem solar cell further includes: a first metal electrode (125) disposed on the surface of the perovskite solar cell functional layer, and a second metal electrode (118) disposed on the surface of the second crystalline silicon solar cell functional layer.

9. The crystalline silicon perovskite tandem solar cell according to claim 7, characterized in that, The first crystalline silicon cell functional layer includes a first carrier collection layer (114) disposed on the surface of a first central region of the crystalline silicon substrate (111), and an interconnect layer (115) disposed on the first carrier collection layer (114); the second crystalline silicon cell functional layer includes a second carrier collection layer (116) disposed on the surface of a second central region of the crystalline silicon substrate (111); or, the first crystalline silicon cell functional layer includes an interconnect layer (115) disposed on the surface of a first central region of the crystalline silicon substrate (111), the second central region of the crystalline silicon substrate (111) includes a plurality of alternating first conductive regions and a plurality of second conductive regions, the surface of the crystalline silicon substrate (111) corresponding to the first conductive region is provided with a first carrier collection layer (114), and the surface of the crystalline silicon substrate (111) corresponding to the second conductive region is provided with a second carrier collection layer (116). Preferably, the conductivity type of the first carrier collection layer (114) is opposite to that of the second carrier collection layer (116); Preferably, the conductivity type of the first carrier collection layer (114) is opposite to that of the crystalline silicon substrate (111); Preferably, the first carrier collection layer (114) is a doped layer formed by directly doping the crystalline silicon substrate (111), or a stacked structure of silicon oxide layer and doped polycrystalline silicon layer, or a stacked structure of intrinsic silicon-containing layer and doped silicon-containing layer containing microcrystalline silicon and / or amorphous silicon. Preferably, the interconnect layer (115) comprises at least one of indium tin oxide, aluminum-doped zinc oxide, and indium cerium oxide; Preferably, the second carrier collection layer (116) comprises a stacked structure of an oxide layer and a doped polycrystalline silicon layer disposed on the surface of the second central region of the crystalline silicon substrate (111), or a stacked structure of an intrinsic silicon-containing layer and a doped silicon-containing layer comprising microcrystalline silicon and / or amorphous silicon.

10. The crystalline silicon perovskite tandem solar cell according to claim 7, characterized in that, The perovskite solar cell functional layer includes a first carrier transport layer (121), a perovskite layer (122), a second carrier transport layer (123), and a first transparent conductive layer (124) stacked from the inside to the outside. Preferably, the perovskite solar cell further includes an interface modification layer disposed between the perovskite layer (122) and the second carrier transport layer (123); Preferably, the perovskite solar cell further includes a barrier layer disposed between the second carrier transport layer (123) and the first transparent conductive layer (124); Preferably, the perovskite solar cell further includes an antireflection layer disposed on the outer surface of the first transparent conductive layer (124).

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