Stacked solar cell and method of manufacturing the same

Abstract

The application relates to a laminated solar cell, wherein a heterojunction solar cell layer comprises a side intrinsic amorphous silicon layer, the thickness of the side intrinsic amorphous silicon layer is 1.5-3 times the thickness of a front intrinsic amorphous silicon layer, and a manufacturing method of the laminated solar cell is provided.The method comprises the following steps: stacking and aligning a plurality of silicon substrates, depositing a side intrinsic amorphous silicon layer on the side of the silicon substrate, and optimizing the structure of the heterojunction solar cell piece.The edge effect in the heterojunction solar cell piece is improved, the performance of the laminated solar cell piece is more stable, and in addition, the etching of the front and rear electrical isolation of the laser is arranged at the side position, so that the dead zone is avoided on the front or back of the solar cell piece.

Description

[Technical Field]

[0001] This application relates to the field of solar cell technology, and more particularly to a tandem solar cell. [Background Technology]

[0002] A tandem solar cell is a type of solar cell composed of multiple solar cell units stacked on top of each other. It combines materials with different band gaps to maximize the utilization of the solar spectrum and improve photoelectric conversion efficiency. A silicon-based tandem solar cell is a device that converts light energy into electrical energy using a multi-layered stack of thin-film silicon wafers. It consists of multiple thin-film layers, each capable of absorbing different wavelengths of light, thus improving the efficiency of the solar cell. The manufacturing process of silicon-based tandem solar cells is relatively complex, requiring the preparation of multiple thin films, which are then stacked together. Each thin film layer has a different band structure and light absorption characteristics, absorbing different wavelengths of light. By optimizing the materials and thicknesses between different layers, the utilization of different wavelengths of light in the spectrum can be maximized.

[0003] Silicon-based tandem solar cells offer numerous advantages. First, their multi-layered stacked structure allows for higher photoelectric conversion efficiency. Second, silicon is an abundant material with relatively low manufacturing costs. Furthermore, silicon-based tandem solar cells exhibit good stability and durability, enabling long-term stable operation under various environmental conditions. However, silicon-based tandem solar cells also present some challenges and problems. First, the manufacturing process is relatively complex, requiring advanced technology and equipment investment. Second, due to the multi-layered structure, silicon-based tandem solar cells are thicker and heavier, making installation and use inconvenient. Moreover, the complexity of the stacked structure results in higher manufacturing costs, currently preventing them from competing with traditional silicon-based solar cells.

[0004] Heterojunction solar cells are one of the commonly used substrates for fabricating silicon-based tandem solar cells. They combine the advantages of ultra-low temperature manufacturing of thin-film solar cells, avoiding the traditional high-temperature processes, and simplifying the process flow to only four parts. The stability of heterojunction solar cells affects the final performance of tandem solar cells; therefore, optimizing the structure of heterojunction solar cells to improve their performance has been a key research focus for those skilled in the art. [Summary of the Invention]

[0005] The purpose of this application is to provide a tandem solar cell, which optimizes the structure of the heterojunction solar cell in the tandem solar cell, improves the edge effect in the heterojunction solar cell, and makes the performance of the tandem solar cell more stable. This application also provides a method for manufacturing the tandem solar cell, which can reduce the requirements for laser processing and simplify the production process by combining the new structure.

[0006] The purpose of this application is achieved through the following technical solution: This application provides a tandem solar cell, including a heterojunction solar cell structure layer and a perovskite solar cell structure layer. The perovskite solar cell structure layer is stacked on the heterojunction solar cell layer. The heterojunction solar cell layer includes a silicon substrate, a front intrinsic amorphous silicon layer is formed on the front side of the silicon substrate, a back intrinsic amorphous silicon layer is formed on the back side of the silicon substrate, a front doped amorphous silicon layer is formed on the front intrinsic amorphous silicon layer, and a back doped amorphous silicon layer is formed on the back intrinsic amorphous silicon layer.

[0007] The side surface of the silicon substrate includes sequentially stacked side intrinsic amorphous silicon layers, a front intrinsic amorphous silicon layer extending from the front to the side surface, and a back intrinsic amorphous silicon layer extending from the back to the side surface.

[0008] The front intrinsic amorphous silicon layer has the same thickness as the back intrinsic amorphous silicon layer, and the thickness of the side intrinsic amorphous silicon layer is 1.5 to 3 times the thickness of the front intrinsic amorphous silicon layer.

[0009] The intrinsic amorphous silicon layer on the side and the intrinsic amorphous silicon layer on the front include an oxide layer with a thickness of 50-500 nm.

[0010] In one embodiment, the side intrinsic amorphous silicon layer extends to the front and back sides of the silicon substrate, respectively.

[0011] In one embodiment, the front-side doped amorphous silicon layer further includes a front-side transparent conductive layer, on which a perovskite functional layer is included.

[0012] In one embodiment, the back-side doped amorphous silicon layer further includes a back-side transparent conductive layer, on which a back-side gate electrode is included.

[0013] In one embodiment, the width of the side intrinsic layer extending to the front and back sides is less than the thickness of the side intrinsic amorphous silicon layer on the side.

[0014] This application also provides a method for manufacturing a tandem solar cell, comprising the following steps:

[0015] Step S1: Clean and texturize the silicon substrate;

[0016] Step S2: Stack and align multiple silicon substrates, and place dummy wafers at the bottom and top;

[0017] Step S3: Place the stack into the vapor deposition chamber and deposit a side intrinsic amorphous silicon layer on the side of the silicon substrate under pressure.

[0018] Step S4: After forming the side intrinsic amorphous silicon layer, a back intrinsic amorphous silicon layer is formed on the back side of the silicon substrate, a front intrinsic amorphous silicon layer and a front doped amorphous silicon layer are formed on the front side of the silicon substrate, and a back doped amorphous silicon layer is formed on the back side of the silicon substrate.

[0019] Step S5: Laser etching is performed on the side surface of the silicon substrate;

[0020] Step S6: A transparent conductive layer and a perovskite functional layer are formed on the front-side doped amorphous silicon layer.

[0021] In one embodiment, a step of separating the stacked silicon substrates is included between step S3 and step S4.

[0022] In one embodiment, step S5 involves stacking multiple silicon substrates and laser etching the sides of the stack.

[0023] In one embodiment, the silicon substrate is N-type doped, the front-side doped amorphous silicon layer is N-type doped, and the doping concentration of the front-side doped amorphous silicon layer is higher than the doping concentration of the silicon substrate.

[0024] In one embodiment, the back-side doped amorphous silicon layer is P-type.

[0025] Compared with the prior art, this application has the following beneficial effects:

[0026] 1. This application protects the side surface by forming an intrinsic amorphous silicon layer before fabricating the intrinsic doped amorphous silicon layers on the front and back sides of the heterojunction solar cell. Based on the formation of the intrinsic amorphous silicon layer on the side surface, it can prevent excessive winding of the doped amorphous silicon layers on the front and back sides and reduce the operational requirements of subsequent laser processing steps.

[0027] 2. The edge is protected by an intrinsic amorphous silicon layer on the side, which avoids the impact on the substrate layer caused by laser etching to remove the coating on the side. The manufacturing method adopted can process solar cells in batches. Although it adds steps, it does not significantly increase the process time.

[0028] 3. The heterojunction solar cell prepared in this application can be well compatible with the perovskite functional layer, and can better realize electrical connection, thereby simplifying the process while ensuring the conversion efficiency and stability of the tandem solar cell;

[0029] 4. By stacking silicon substrates, this application can perform batch processing on the side of the substrate, including depositing an intrinsic amorphous silicon layer and laser etching. The laser etching with front and rear electrical isolation is set on the side, avoiding processing the front or back of the solar cell and reducing the dead zone of the irradiated surface. [Attached Image Description]

[0030] Figure 1 This is a schematic diagram of the structure of the tandem solar cell of this application.

[0031] Figure 2 This is a flowchart of the manufacturing method of the tandem solar cell of this application.

[0032] Figure 3 This is a schematic diagram of the manufacturing process of the tandem solar cell of this application.

Detailed Implementation Methods

[0033] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0034] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the tandem solar cell of this application. In a preferred embodiment of the tandem solar cell of this application, a side intrinsic amorphous silicon layer 200 is formed before the intrinsic doped amorphous silicon layer on the front and back sides of the heterojunction solar cell is formed. The side side is protected first. Based on the formation of the side intrinsic amorphous silicon layer 200, the excessive generation of the doped amorphous silicon layer 302 on the front and back sides can be prevented. This application provides a tandem solar cell, including a heterojunction solar cell structure layer and a perovskite solar cell structure layer. The perovskite solar cell structure layer is stacked on the heterojunction solar cell layer. The heterojunction solar cell layer includes a silicon substrate 100. A front intrinsic amorphous silicon layer 401 is formed on the front side of the silicon substrate 100, and a back intrinsic amorphous silicon layer 301 is formed on the back side of the silicon substrate 100. A front doped amorphous silicon layer 402 is formed on the front intrinsic amorphous silicon layer 401, and a back doped amorphous silicon layer 302 is formed on the back intrinsic amorphous silicon layer 301. A side intrinsic amorphous silicon layer 200 is formed before fabricating the front and back intrinsic doped amorphous silicon layers of the heterojunction solar cell to protect the sides. Compared with the prior art, this application forms the intrinsic amorphous silicon layer on the sides first, increasing the isolation performance of the cell at the edge.

[0037] The silicon substrate 100 includes a side intrinsic amorphous silicon layer 200, a front intrinsic amorphous silicon layer 401 extending from the front to the side, and a back intrinsic amorphous silicon layer 301 extending from the back to the side, which are stacked sequentially on the side. In the above structure, the front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 are prepared in a single-sided manner. No specific isolation structure is set during the manufacturing process. It is only necessary to place the silicon wafer on the carrier. During the preparation, the front intrinsic amorphous silicon layer 401 is allowed to extend to the side and even to the back. Correspondingly, when preparing the back intrinsic amorphous silicon layer 301, the back intrinsic amorphous silicon layer 301 is allowed to extend to the side and even to the front.

[0038] The front intrinsic amorphous silicon layer 401 has the same thickness as the back intrinsic amorphous silicon layer 301, and the thickness of the side intrinsic amorphous silicon layer 200 is 1.5 to 3 times the thickness of the front intrinsic amorphous silicon layer 401. In order to further protect the front side, since the thickness of the front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 is usually limited, appropriately increasing the side intrinsic amorphous silicon layer 200 can extend the lateral distance of the substrate from the side. The optimized structure allows the laser to be used to fabricate the electrical isolation structure from the side, which can protect the structure of the heterojunction solar cell. In addition, the formation of the side intrinsic amorphous silicon layer 200 can ensure the maintenance of edge insulation performance. By forming multiple layers of undoped amorphous silicon layers on the side, it is possible to further prevent dopants from diffusing into the amorphous silicon layer and affecting the insulation path.

[0039] The intrinsic amorphous silicon layer 200 on the side and the intrinsic amorphous silicon layer 401 on the front include an oxide layer with a thickness of 50-500 nm. The oxide layer can be etched only to the oxide layer by adjusting specific parameters such as the energy and duration of subsequent laser processing. The oxide layer can further prevent dopants from diffusing into the substrate. The oxide layer has two main functions: it can serve as a stop target layer for laser etching and it can also prevent diffusion. In subsequent processing steps, since the oxide layer is introduced only between the intrinsic amorphous silicon layer 200 on the side and the intrinsic amorphous silicon layer 401 on the front, the oxide layer on the side can be removed by solution etching, thereby removing the layers that will be formed after the oxide layer. Specifically, after forming the oxide transparent conductive layer, the amorphous silicon layer can be removed using an alkaline solution with the side oxide layer and the oxide transparent conductive layer as templates.

[0040] Specifically, the intrinsic amorphous silicon layer 200 extends to the front and back sides of the silicon substrate 100, respectively. The front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 are fabricated using a single-sided method. During the fabrication of the intrinsic amorphous silicon layer 200, multiple silicon substrates 100 can be stacked. The stack is placed in a vapor deposition chamber, and under pressure, the intrinsic amorphous silicon layer 200 is deposited on the sides of the silicon substrates 100. Although the silicon substrates 100 are stacked during fabrication, and pressure is applied to the stack in a further technical solution, this applied pressure does not eliminate gaps at the microscopic level. During the formation of the intrinsic amorphous silicon layer 200 on the side, a certain amount of wrap-around plating can be formed on the front side, so that the intrinsic amorphous silicon layer 200 can completely cover the side. Furthermore, because the silicon substrates 100 are stacked, a large area of ​​the intrinsic amorphous silicon layer 200 will not be deposited on the front side, ensuring the fabrication and application of other layers of the solar cell while maintaining the relevant design.

[0041] Specifically, the front-side doped amorphous silicon layer 402 further includes a front-side transparent conductive layer 500, and the front-side transparent conductive layer 500 includes a perovskite functional layer 600. The transparent conductive layer and the perovskite functional layer 600 adopt common structures, such as the perovskite functional layer 600 including an electron transport layer, a hole transport layer, and a top electrode layer. The substrate can be a commonly used substrate in the art, such as a glass substrate. A transparent conductive layer 2 can be disposed on the substrate; the relevant materials can be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc gallium oxide (GZO), and zinc indium oxide (IZO). Because a side intrinsic amorphous silicon layer 200 is formed on the side, in the edge-formed structure, the side will be relatively higher than the surface. When forming the front transparent conductive layer 500...

[0042] Specifically, the back-side doped amorphous silicon layer 302 further includes a back-side transparent conductive layer, on which a back-side gate electrode (not specifically shown in the figures) is included. The steps of forming the back-side transparent conductive layer and forming the back-side gate electrode can be performed using methods and equipment commonly used in heterojunction fabrication, and this application does not impose specific limitations on them.

[0043] Specifically, the width of the intrinsic side layer extending to the front and back sides is less than the thickness of the intrinsic side amorphous silicon layer 200 on the side. A certain amount of wrap-around plating is formed on the front side, so that the intrinsic side amorphous silicon layer 200 can completely cover the side. Furthermore, since the silicon substrate 100 is stacked, there is no large-area deposition of the intrinsic side amorphous silicon layer 200 on the front and back sides, and the fabrication of other layers on the front and back sides is not affected, ensuring the functionality of other layers of the solar cell.

[0044] See Figure 2 , Figure 3 , Figure 2 This is a flowchart of the manufacturing method of the tandem solar cell of this application. Figure 3 This is a schematic diagram of the manufacturing process of the tandem solar cell of this application. This application also provides a method for manufacturing a tandem solar cell, including the following steps:

[0045] Step S1: Clean and texturize the silicon substrate 100;

[0046] Step S2: Stack and align multiple silicon substrates 100, and place dummy wafers at the bottom and top; placing dummy wafers can prevent the formation of an intrinsic amorphous silicon layer on the surface of the silicon substrates 100, and can facilitate the application of pressure to the stack through rods to compress the stack.

[0047] Step S3: Place the stack into the vapor deposition chamber. Under pressure applied to the stack, deposit an intrinsic amorphous silicon layer 200 on the side of the silicon substrate 100. The vapor deposition method can be either PECVD or LPCVD. Due to the pressure applied to the stack, the gap between the silicon substrates 100 is minimized, making it difficult for gas to enter the silicon substrates 100 over a large area. Some gas can enter at the edge, thereby generating a partial amorphous silicon layer at the edge. Using this principle, the required wrap-around plating is formed on the side. Here, wrap-around plating refers to plating performed on the surface where the formation of a material layer is not desired, and does not specifically refer to plating from the front to the back or from the back to the front.

[0048] Step S4: After forming the side intrinsic amorphous silicon layer 200, a back intrinsic amorphous silicon layer 301 is formed on the back side of the silicon substrate 100. A front intrinsic amorphous silicon layer 401 and a front doped amorphous silicon layer 402 are formed on the front side of the silicon substrate 100. A back doped amorphous silicon layer 302 is formed on the back side of the silicon substrate 100.

[0049] Step S5: Laser etching is performed on the side surface of the silicon substrate 100;

[0050] Step S6: A transparent conductive layer and a perovskite functional layer 600 are formed on the front-side doped amorphous silicon layer 402.

[0051] Before fabricating the intrinsically doped amorphous silicon layers on the front and back sides of a heterojunction solar cell, a side intrinsic amorphous silicon layer 200 is formed to protect the sides. Compared with the prior art, this application can increase the isolation performance of the cell at the edge. The front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 are fabricated separately using a single-sided method. No specific isolation structure is set during the manufacturing process. It is only necessary to place the silicon wafer on the carrier plate. During the fabrication, the front intrinsic amorphous silicon layer 401 is allowed to extend to the side and even to the back side. Correspondingly, when fabricating the back intrinsic amorphous silicon layer 301, the back intrinsic amorphous silicon layer 301 is allowed to extend to the side and even to the front side.

[0052] In the fabrication process, in order to further protect the front side, since the thickness of the front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 is usually limited, appropriately increasing the side intrinsic amorphous silicon layer 200 can extend the lateral distance of the substrate from the side. The optimized structure allows the laser to fabricate the electrical isolation structure from the side, which can protect the structure of the heterojunction solar cell.

[0053] Specifically, between steps S3 and S4, there is also a step of separating the multiple stacked silicon substrates 100. The front intrinsic amorphous silicon layer 401 and the back intrinsic amorphous silicon layer 301 are fabricated using a single-sided method. No specific isolation structure is set during the manufacturing process. Since the silicon substrates 100 are stacked together in the previous steps, the stack is divided into individual wafers during single-wafer processing. An automated single-wafer pick-up method can be used to separate the silicon substrates 100 within the stack.

[0054] Specifically, in step S5, multiple silicon substrates 100 are stacked, and the sides of the stack are laser-etched. The optimized structure allows for the fabrication of an electrically isolated structure from the side using laser, protecting the structure of the heterojunction solar cell. An oxide layer may also be included between the side intrinsic amorphous silicon layer 200 and the front intrinsic amorphous silicon layer 401. The oxide layer can be set by adjusting specific parameters such as the energy and duration of subsequent laser processing, etching only down to the oxide layer. Furthermore, the oxide layer can further prevent dopants from diffusing into the substrate. The edge is protected by the intrinsic amorphous silicon layer on the side, avoiding the impact on the substrate layer caused by laser etching to remove the surrounding coating. The manufacturing method allows for batch processing of solar cells. Although it adds steps, it does not significantly increase the process time.

[0055] Specifically, the silicon substrate 100 is N-type doped, the front-side doped amorphous silicon layer 402 is N-type doped, and the doping concentration of the front-side doped amorphous silicon layer 402 is higher than that of the silicon substrate 100.

[0056] Specifically, the back-side doped amorphous silicon layer 302 is P-type doped. The silicon substrate 100 is N-type doped. The heterojunction solar cell is a back-emitter junction, and a perovskite functional layer 600 is formed on the front side, which can achieve double-sided light transmission, thereby fabricating a bifacial tandem solar cell.

[0057] Performance testing and comparison were conducted using a tandem solar cell structure without an intrinsic amorphous silicon layer on the sides for comparison. Other structures were fabricated using the same parameters. For the tandem solar cell without an intrinsic amorphous silicon layer on the sides, laser insulation was also applied to the sides. Eta (efficiency), Voc (open-circuit voltage), Isc (short-circuit current), and FF (fill factor) were measured. The results show that the efficiency of the tandem solar cell in this application reaches 33.5%. Using the comparative example as a baseline, the conversion efficiency of the embodiment is improved by 0.3%. This is mainly due to the full utilization of the surface area, reducing current loss on the sides. Additionally, the reduced optical loss of amorphous silicon and smaller shading area effectively increase the short-circuit current. It is speculated that due to laser etching on the sides, in the absence of an intrinsic amorphous silicon layer, the laser on the sides may have affected the front structure. The embodiment improves the fill factor compared to the tandem solar cell without an intrinsic amorphous silicon layer by improving contact. There was no significant difference in the open-circuit voltage between the two cells. Overall, the gains in Isc and FF outweighed the difference in Voc, resulting in a final efficiency improvement of 0.3%.

[0058] As described above, this application provides a tandem solar cell, wherein the heterojunction solar cell layer includes a side intrinsic amorphous silicon layer. The thickness of the side intrinsic amorphous silicon layer is 1.5 to 3 times the thickness of the front intrinsic amorphous silicon layer. The side intrinsic amorphous silicon layer is formed before fabricating the intrinsic doped amorphous silicon layers on the front and back sides of the heterojunction solar cell, thus protecting the sides first. The manufacturing method of the tandem solar cell in this application involves stacking and aligning multiple silicon substrates, depositing a side intrinsic amorphous silicon layer on the sides of the silicon substrates, thus optimizing the structure of the heterojunction solar cell, improving the edge effect in the heterojunction solar cell, and making the performance of the tandem solar cell more stable. Furthermore, the laser etching for front-to-back electrical isolation is located on the side, avoiding the formation of dead zones on the front or back of the solar cell.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A tandem solar cell, comprising a heterojunction solar cell structure layer and a perovskite solar cell structure layer, wherein the perovskite solar cell structure layer is stacked on the heterojunction solar cell layer, characterized in that: The heterojunction solar cell layer includes a silicon substrate, a front intrinsic amorphous silicon layer formed on the front side of the silicon substrate, a back intrinsic amorphous silicon layer formed on the back side of the silicon substrate, a front doped amorphous silicon layer formed on the front intrinsic amorphous silicon layer, and a back doped amorphous silicon layer formed on the back intrinsic amorphous silicon layer. The side surface of the silicon substrate includes sequentially stacked side intrinsic amorphous silicon layers, a front intrinsic amorphous silicon layer extending from the front to the side surface, and a back intrinsic amorphous silicon layer extending from the back to the side surface. The front intrinsic amorphous silicon layer has the same thickness as the back intrinsic amorphous silicon layer, and the thickness of the side intrinsic amorphous silicon layer is 1.5 to 3 times the thickness of the front intrinsic amorphous silicon layer. The intrinsic amorphous silicon layer on the side and the intrinsic amorphous silicon layer on the front include an oxide layer with a thickness of 50-500 nm.

2. The tandem solar cell as described in claim 1, characterized in that, The intrinsic amorphous silicon layers on the sides extend to the front and back sides of the silicon substrate, respectively.

3. The tandem solar cell as described in claim 1, characterized in that, The front-side doped amorphous silicon layer also includes a front-side transparent conductive layer, and the front-side transparent conductive layer includes a perovskite functional layer.

4. The tandem solar cell as described in claim 1, characterized in that, The back-side doped amorphous silicon layer also includes a back-side transparent conductive layer, on which a back-side gate electrode is included.

5. The tandem solar cell as described in claim 2, characterized in that, The width of the intrinsic amorphous silicon layer extending to the front and back sides is less than the thickness of the intrinsic amorphous silicon layer on the side.

6. A method for manufacturing a tandem solar cell, characterized in that, Includes the following steps: Step S1: Clean and texturize the silicon substrate; Step S2: Stack and align multiple silicon substrates, and place dummy wafers at the bottom and top; Step S3: Place the stack into the vapor deposition chamber and deposit a side intrinsic amorphous silicon layer on the side of the silicon substrate under pressure. Step S4: After forming the side intrinsic amorphous silicon layer, a back intrinsic amorphous silicon layer is formed on the back side of the silicon substrate, a front intrinsic amorphous silicon layer and a front doped amorphous silicon layer are formed on the front side of the silicon substrate, and a back doped amorphous silicon layer is formed on the back side of the silicon substrate. Step S5: Laser etching is performed on the side surface of the silicon substrate; Step S6: A transparent conductive layer and a perovskite functional layer are formed on the front-side doped amorphous silicon layer.

7. The method for manufacturing a tandem solar cell as described in claim 6, characterized in that, Between step S3 and step S4, there is also a step of separating the multiple silicon substrates that are stacked together.

8. The method for manufacturing a tandem solar cell as described in claim 6, characterized in that, In step S5, multiple silicon substrates are stacked, and the sides of the stack are laser-etched.

9. The method for manufacturing a tandem solar cell as described in claim 6, characterized in that, The silicon substrate is N-type doped, the front-side doped amorphous silicon layer is N-type doped, and the doping concentration of the front-side doped amorphous silicon layer is higher than that of the silicon substrate.

10. The method for manufacturing a tandem solar cell as described in claim 9, characterized in that, The back-side doped amorphous silicon layer is P-type.

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