Stacked solar cell

Abstract

The application relates to the technical field of solar cells, in particular to a laminated solar cell. Embodiments of the application provide a laminated solar cell, which comprises, from the front surface to the back surface, a perovskite top cell, an interface layer and a crystalline silicon bottom cell which are sequentially stacked; the crystalline silicon bottom cell comprises, from the front surface to the back surface, a first passivation layer, a second passivation layer, a silicon substrate, a silicon oxide layer, a doped polycrystalline silicon layer, a transparent conductive layer and a back surface metal electrode which are sequentially stacked; the first passivation layer comprises at least one of a doped amorphous silicon layer, a doped nanocrystalline silicon layer or a doped microcrystalline silicon layer; and the second passivation layer is an intrinsic amorphous silicon layer. The laminated solar cell provided by the application has almost no parasitic absorption in the wavelength range of more than 750 nm, so that the laminated solar cell has good passivation effect and current gain, and the photoelectric conversion efficiency of the laminated solar cell is improved.

Description

Technical Field

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

[0002] Perovskite / silicon tandem solar cells have become a research hotspot in the photovoltaic field due to their ability to surpass the photoelectric conversion efficiency of single-junction solar cells. Among them, the two-end structure has attracted much attention due to its simple structure and ease of industrialization. In perovskite tandem solar cells, the choice of the bottom cell is crucial to overall performance and cost control. Currently, the mainstream solutions mainly employ heterojunction solar cells (HJT) or tunnel oxide passivated contact cells (…). It serves as the base battery. Compared to HJT batteries, The battery has a more significant manufacturing cost advantage: its production process is more compatible with existing PERC battery production lines, and mass production can be achieved through upgrades to existing production lines, greatly reducing equipment investment and manufacturing costs. Therefore, it is gradually becoming the preferred solution for the bottom cell of perovskite tandem solar cells.

[0003] But tradition The battery uses The film layer, being an insulating structure, cannot meet the conductivity requirements of the bottom cell in a stacked battery. It needs to be replaced with a material that combines low resistivity and good passivation properties. The replacement structure causes significant parasitic absorption in the wavelength range greater than 750 nm in the tandem solar cells. This results in the premature consumption of long-wavelength photons that should have been absorbed by the silicon substrate of the bottom cell, ultimately leading to a substantial loss of the bottom cell's current density and limiting its application. This improves the overall performance of tandem solar cells with a base cell.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0005] This application provides tandem solar cells to solve or alleviate one or more of the technical problems mentioned above.

[0006] The first aspect of this application provides a tandem solar cell, including a perovskite top cell, an interface layer, and a crystalline silicon bottom cell stacked sequentially from the front to the back.

[0007] The crystalline silicon bottom cell comprises, from front to back, a first passivation layer, a second passivation layer, a silicon substrate, a silicon oxide layer, a doped polycrystalline silicon layer, a transparent conductive layer, and a back metal electrode, which are stacked sequentially.

[0008] The first passivation layer includes at least one of a doped amorphous silicon layer, a doped nanocrystalline silicon layer, or a doped microcrystalline silicon layer;

[0009] The second passivation layer is an intrinsic amorphous silicon layer.

[0010] Optionally, the silicon substrate is a p-type silicon substrate or an n-type silicon substrate.

[0011] Optionally, the doping type of the first passivation layer is p-type or n-type.

[0012] Optionally, the doping type of the doped polycrystalline silicon layer is p-type or n-type.

[0013] Optionally, the thickness of the first passivation layer is 5nm to 35nm.

[0014] Optionally, the thickness of the second passivation layer is 4nm to 10nm.

[0015] Optionally, the thickness of the silicon oxide layer is 1 nm to 5 nm.

[0016] Optionally, the thickness of the doped polycrystalline silicon layer is 10 nm to 130 nm.

[0017] Optionally, the thickness of the transparent conductive layer is 10 nm to 130 nm.

[0018] Optionally, the thickness of the interface layer is 10nm~130nm.

[0019] The embodiments of this application employing the above-described technical solution may have the following advantages:

[0020] The tandem solar cell provided in this application has almost no parasitic absorption in the wavelength range above 750nm, which gives the tandem solar cell a better passivation effect and current gain, thereby improving the photoelectric conversion efficiency of the tandem solar cell. Attached Figure Description

[0021] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0022] Figure 1 This is a schematic diagram of the structure of the stacked solar cell provided in the embodiments of this application.

[0023] Figure 2 The results show the light absorption test results for the second passivation layer, the crystalline silicon layer, the doped polycrystalline silicon layer, and the silicon oxide layer.

[0024] Figure 3 The external quantum efficiency test results are for the tandem solar cell provided in Embodiment 1 of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] Figure 1 In the middle: 100, perovskite layer; 101, electron transport layer; 102, antireflection layer; 103, front metal electrode; 104, hole transport layer;

[0027] 200. Interface layer;

[0028] 300, Silicon substrate; 301, Silicon oxide layer; 302, Doped polycrystalline silicon layer; 303, Second passivation layer; 304, First passivation layer; 305, Transparent conductive layer; 306, Back metal electrode. Detailed Implementation

[0029] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0030] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0034] This application provides a tandem solar cell, comprising a perovskite top cell, an interface layer 200, and a crystalline silicon bottom cell stacked sequentially from front to back. The crystalline silicon bottom cell, from front to back, includes a first passivation layer 304, a second passivation layer 303, a silicon substrate 300, a silicon oxide layer 301, a doped polycrystalline silicon layer 302, a transparent conductive layer 305, and a back metal electrode 306 stacked sequentially from front to back. The first passivation layer 304 includes at least one of amorphous silicon, nanocrystalline silicon, or microcrystalline silicon. The second passivation layer 303 is an intrinsic amorphous silicon layer. Based on this, the light-receiving surface of the crystalline silicon bottom cell in the tandem solar cell provided in this application uses amorphous silicon and doped microcrystalline silicon oxide to form a silicon oxide layer and a doped polycrystalline silicon layer, resulting in almost no parasitic absorption in the wavelength range exceeding 750 nm. This gives the tandem solar cell better passivation and current gain, improving the photoelectric conversion efficiency of the tandem solar cell.

[0035] Exemplary embodiments according to this application will now be described in more detail. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0036] like Figure 1 As shown, this application provides a tandem solar cell, including a perovskite top cell, an interface layer 200, and a crystalline silicon bottom cell stacked sequentially from the front to the back. The crystalline silicon bottom cell includes, from the front to the back, a first passivation layer 304, a second passivation layer 303, a silicon substrate 300, a silicon oxide layer 301, a doped polycrystalline silicon layer 302, a transparent conductive layer 305, and a back metal electrode 306 stacked sequentially. The first passivation layer 304 includes at least one of a doped amorphous silicon layer, a doped nanocrystalline silicon layer, or a doped microcrystalline silicon layer. The second passivation layer 303 is an intrinsic amorphous silicon layer.

[0037] In this embodiment, the backlight surface of the crystalline silicon bottom cell uses a passivation film structure of TOPCon, which includes silicon oxide and doped polycrystalline silicon; the light-receiving surface of the crystalline silicon bottom cell uses a passivation film structure of HJT, which includes amorphous silicon and doped microcrystalline silicon hydrogen oxide, forming a bottom cell structure hybridized with HJT and TOPCon.

[0038] In this embodiment, the light-receiving surface of the crystalline silicon substrate cell is formed by amorphous silicon and doped microcrystalline silicon hydrogen oxide to form a silicon oxide layer and a doped polycrystalline silicon layer, so that the tandem solar cell has almost no parasitic absorption in the wavelength range exceeding 750nm, ensuring that the tandem solar cell has a good passivation effect and current gain; the possible reason is that the combination of silicon oxide layer and doped polycrystalline silicon layer reduces light reflection loss, ensures that photons reach the silicon substrate directly, and reduces the reflection loss of long wavelength light.

[0039] The structure of the second passivation layer and the first passivation layer formed by silicon oxide and doped polycrystalline silicon on the back surface of the crystalline silicon bottom cell has a low resistance and can utilize existing TOPCon production capacity and equipment to reduce the manufacturing cost of the bottom cell.

[0040] In optional embodiments, such as Figure 1 As shown, the perovskite top solar cell includes a front metal electrode 103, an antireflection layer 102, an electron transport layer 101, a perovskite layer 100, and a hole transport layer 104 stacked sequentially.

[0041] In an optional embodiment, the silicon substrate 300 is a p-type silicon substrate or an n-type silicon substrate.

[0042] In an optional embodiment, the silicon substrate 300 is crystalline silicon.

[0043] In an optional embodiment, the first passivation layer 304 is doped with p-type or n-type.

[0044] In an optional embodiment, the first passivation layer 304 is a doped microcrystalline silicon layer.

[0045] In optional embodiments, the first passivation layer 304 is a hydrogenated amorphous silicon (a-Si:H) layer, a hydrogenated nanocrystalline silicon (nc-Si:H) layer, a hydrogenated microcrystalline silicon (uc-Si:H) layer, or a hydrogenated nanocrystalline silicon oxide layer. ) layer, hydrogenated microcrystalline silicon oxide ( At least one of the following: ) layer and microcrystalline silicon hydrogen oxide layer.

[0046] In an optional embodiment, the first passivation layer 304 is a microcrystalline silicon hydrogen oxide layer.

[0047] In an optional embodiment, the doping type of the doped polysilicon layer 302 is p-type or n-type.

[0048] In this embodiment, the silicon substrate 300, the first passivation layer 304, and the doped polysilicon layer 302 have the same doping type.

[0049] In an optional embodiment, the thickness of the first passivation layer 304 is 5 nm to 35 nm (exemplary thicknesses are 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and 35 nm).

[0050] In an optional embodiment, the thickness of the second passivation layer 303 is 4 nm to 10 nm (exemplary thicknesses are 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, and 10 nm).

[0051] In an optional embodiment, the thickness of the silicon oxide layer 301 is 1nm to 5nm (exemplary thicknesses are 1nm, 2nm, 3nm, 4nm, and 5nm).

[0052] In an optional embodiment, the thickness of the doped polycrystalline silicon layer 302 is 10~130 nm (exemplary thicknesses are 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, and 130 nm).

[0053] In an optional embodiment, the thickness of the transparent conductive layer 305 is 10 nm to 130 nm (exemplary thicknesses are 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, and 130 nm).

[0054] In an optional embodiment, the thickness of the interface layer 200 is 10 nm to 130 nm (exemplary thicknesses are 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, and 130 nm).

[0055] The thickness values ​​obtained in this application are average thicknesses.

[0056] In optional embodiments, the material used for the back metal electrode 306 includes, but is not limited to, at least one of the following metals: copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), cobalt (Co), gold (Au), molybdenum (Mo), or chromium (Cr).

[0057] In an optional embodiment, the back metal electrode 306 is a silver electrode.

[0058] In optional embodiments, the front metal electrode 103 is made of at least one of the following metals: copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), cobalt (Co), gold (Au), molybdenum (Mo), or chromium (Cr).

[0059] In an optional embodiment, the front metal electrode 103 is a silver electrode.

[0060] In optional embodiments, the transparent conductive layer may be made of materials including but not limited to ITO, IZO, IWO, FTO, ICO, AZO, ATO, and GZO, and may be prepared by methods including but not limited to magnetron sputtering (PVD) and reactive plasma deposition (RPD).

[0061] In optional embodiments, the materials used for the interface layer include, but are not limited to, ITO, IZO, IWO, FTO, ICO, AZO, ATO, and GZO, and the preparation methods include, but are not limited to, magnetron sputtering (PVD) and reactive plasma deposition (RPD).

[0062] This application provides a method for fabricating a tandem solar cell, comprising the following steps:

[0063] S1. Silicon oxide and doped polycrystalline silicon are sequentially deposited on the back surface of a silicon substrate 300 to obtain a silicon oxide layer 301 and a doped polycrystalline silicon layer 302, respectively. The thickness of the silicon oxide layer 301 is 1 nm to 5 nm; the thickness of the doped polycrystalline silicon layer 302 is 10 nm to 130 nm.

[0064] S2. Amorphous silicon and doped microcrystalline silicon hydrogen oxide are sequentially deposited on the light-receiving surface of the silicon substrate 300 to obtain a second passivation layer 303 (intrinsic amorphous silicon layer) and a first passivation layer 304 (microcrystalline silicon hydrogen oxide layer), respectively. The thickness of the second passivation layer 303 is 4nm~10nm, and the thickness of the first passivation layer 304 is 5nm~35nm.

[0065] S3. ITO (indium tin oxide) is deposited on the back surface of the doped polycrystalline silicon layer 302 to form an ITO film as a transparent conductive layer, wherein the thickness of the transparent conductive layer 305 is 10nm~130nm.

[0066] S4. Hole transport layer 104, perovskite layer 100, electron transport layer 101, and antireflection layer 102 are sequentially formed on the light-receiving surface of interface layer 200.

[0067] S5. A front metal electrode 103 is formed on the light-receiving surface of the antireflection layer 102;

[0068] S6. A back metal electrode 306 is formed on the back surface of the transparent conductive layer 305.

[0069] The fabrication process of the tandem solar cell in this application adopts conventional technology, and the specific form is not limited. Any structure that can obtain a tandem solar cell is acceptable.

[0070] The fabrication method of the perovskite top cell in this application embodiment is not limited. The perovskite top cell includes a front metal electrode 103, an anti-reflection layer 102, an electron transport layer 101, a perovskite layer 100, and a hole transport layer 104 stacked sequentially.

[0071] Example 1

[0072] like Figure 1As shown, this embodiment provides a tandem solar cell, including a perovskite top cell, an interface layer 200, and a crystalline silicon bottom cell stacked sequentially from the front to the back. The crystalline silicon bottom cell includes, from the front to the back, a first passivation layer 304, a second passivation layer 303, a silicon substrate 300, a silicon oxide layer 301, a doped polycrystalline silicon layer 302, a transparent conductive layer 305, and a back metal electrode 306 stacked sequentially. The first passivation layer 304 is a microcrystalline silicon hydrogen oxide layer, and the second passivation layer 303 is an intrinsic amorphous silicon layer.

[0073] like Figure 1 As shown, the perovskite top solar cell includes a front metal electrode 103, an antireflection layer 102, an electron transport layer 101, a perovskite layer 100, and a hole transport layer 104 stacked sequentially.

[0074] The silicon substrate 300 is a p-type silicon substrate.

[0075] The silicon substrate 300 is crystalline silicon.

[0076] The first passivation layer 304 is p-type doped.

[0077] The first passivation layer 304 is a doped microcrystalline silicon layer.

[0078] The doped polycrystalline silicon layer 302 is of the n-type doping type.

[0079] The thickness of the first passivation layer 304 is 20 nm.

[0080] The thickness of the second passivation layer 303 is 6 nm.

[0081] The thickness of the silicon oxide layer 301 is 3 nm.

[0082] The thickness of the doped polycrystalline silicon layer 302 is 100 nm.

[0083] The thickness of the transparent conductive layer 305 is 90 nm.

[0084] The thickness of the interface layer 200 is 100 nm.

[0085] The back metal electrode 306 is a silver electrode.

[0086] The front metal electrode 103 is a silver electrode.

[0087] The transparent conductive layer is made of ITO.

[0088] The interface layer is made of ITO.

[0089] Example 2

[0090] like Figure 1As shown, this embodiment provides a tandem solar cell, including a perovskite top cell, an interface layer 200, and a crystalline silicon bottom cell stacked sequentially from the front to the back. The crystalline silicon bottom cell includes, from the front to the back, a first passivation layer 304, a second passivation layer 303, a silicon substrate 300, a silicon oxide layer 301, a doped polycrystalline silicon layer 302, a transparent conductive layer 305, and a back metal electrode 306 stacked sequentially. The first passivation layer 304 is a microcrystalline silicon hydrogen oxide layer, and the second passivation layer 303 is an intrinsic amorphous silicon layer.

[0091] like Figure 1 As shown, the perovskite top solar cell includes a front metal electrode 103, an antireflection layer 102, an electron transport layer 101, a perovskite layer 100, and a hole transport layer 104 stacked sequentially.

[0092] The silicon substrate 300 is an n-type silicon substrate.

[0093] The silicon substrate 300 is crystalline silicon.

[0094] The first passivation layer 304 is n-type doped.

[0095] The first passivation layer 304 is a doped microcrystalline silicon layer.

[0096] The doped polycrystalline silicon layer 302 is p-type.

[0097] The thickness of the first passivation layer 304 is 5 nm.

[0098] The thickness of the second passivation layer 303 is 4 nm.

[0099] The thickness of the silicon oxide layer 301 is 1 nm.

[0100] The thickness of the doped polycrystalline silicon layer 302 is 10 nm.

[0101] The thickness of the transparent conductive layer 305 is 10 nm.

[0102] The thickness of the interface layer 200 is 10 nm.

[0103] The back metal electrode 306 is a silver electrode.

[0104] The front metal electrode 103 is a silver electrode.

[0105] The transparent conductive layer is made of ITO.

[0106] The interface layer is made of ITO.

[0107] Example 3

[0108] like Figure 1As shown, this embodiment provides a tandem solar cell, including a perovskite top cell, an interface layer 200, and a crystalline silicon bottom cell stacked sequentially from the front to the back. The crystalline silicon bottom cell includes, from the front to the back, a first passivation layer 304, a second passivation layer 303, a silicon substrate 300, a silicon oxide layer 301, a doped polycrystalline silicon layer 302, a transparent conductive layer 305, and a back metal electrode 306 stacked sequentially. The first passivation layer 304 is a microcrystalline silicon hydrogen oxide layer, and the second passivation layer 303 is an intrinsic amorphous silicon layer.

[0109] like Figure 1 As shown, the perovskite top solar cell includes a front metal electrode 103, an antireflection layer 102, an electron transport layer 101, a perovskite layer 100, and a hole transport layer 104 stacked sequentially.

[0110] The silicon substrate 300 is a p-type silicon substrate.

[0111] The silicon substrate 300 is crystalline silicon.

[0112] The first passivation layer 304 is p-type doped.

[0113] The first passivation layer 304 is a doped microcrystalline silicon layer.

[0114] The doped polycrystalline silicon layer 302 is of the n-type doping type.

[0115] The thickness of the first passivation layer 304 is 35 nm.

[0116] The thickness of the second passivation layer 303 is 10 nm.

[0117] The thickness of the silicon oxide layer 301 is 5 nm.

[0118] The thickness of the doped polycrystalline silicon layer 302 is 130 nm.

[0119] The thickness of the transparent conductive layer 305 is 130 nm.

[0120] The thickness of the interface layer 200 is 130 nm.

[0121] The back metal electrode 306 is a silver electrode.

[0122] The front metal electrode 103 is a silver electrode.

[0123] The transparent conductive layer is made of ITO.

[0124] The interface layer is made of ITO.

[0125] Performance testing

[0126] Light absorption tests were performed on the second passivation layer, the crystalline silicon layer, the doped polycrystalline silicon layer, and the silicon oxide layer. The test results are shown in [Figure number missing]. Figure 2 .

[0127] Figure 2 The structure includes a second passivation layer (a-Si:H), a crystalline silicon layer (c-Si), a doped polycrystalline silicon layer (poly-Si), and a silicon oxide layer (…). The light absorption coefficient at different wavelengths.

[0128] from Figure 2 As can be seen, the second passivation layer provided in this application has lower light absorption at wavelengths greater than 750 nm than other passivation layers, and its absorption coefficient is extremely high (close to) at short wavelengths (300-700 nm). The absorption capacity decreases rapidly with increasing wavelength, and its absorption capacity for visible to near-infrared light is significantly reduced, making it suitable for utilizing short-wavelength light. The light-receiving surface of the crystalline silicon bottom cell uses a second passivation layer formed by amorphous silicon and a first passivation layer formed by doped microcrystalline silicon hydrogen oxide, so that the tandem solar cell has almost no parasitic absorption in the wavelength range above 750nm, ensuring that the tandem solar cell has a good passivation effect and current gain.

[0129] The external quantum efficiency of the tandem solar cell provided in Embodiment 1 of this application was tested, and the test results are shown in [the table below]. Figure 3 .

[0130] from Figure 3 As can be seen from the data, the effective EQE (external quantum efficiency) response wavelength of the perovskite top cell in the tandem solar cell provided in Embodiment 1 of this application is concentrated around 300-750nm (short-to-medium wavelength region), covering the visible light to part of the near-infrared initial segment, making fuller use of short wavelength light; the effective EQE (external quantum efficiency) response wavelength of the crystalline silicon bottom cell is mainly around 600-1200nm (medium-to-long wavelength region), and there is some overlap between the crystalline silicon bottom cell and the perovskite top cell in the 600-750nm range, achieving complementarity between short and medium-to-long wavelengths; from Figure 3 The results show that the EQE peak of both the perovskite top solar cell (Top) and the crystalline silicon bottom solar cell (Bottom) reaches 90%, indicating that the crystalline silicon bottom solar cell and the perovskite top solar cell have excellent photon-electron conversion efficiency for matching wavelengths; from Figure 3 The data shows that the current density corresponding to the perovskite top solar cell (Top) is 19.26. The corresponding current density for a crystalline silicon bottom-mounted solar cell is 19.96. Compared to perovskite top cells, crystalline silicon bottom cells have a better photon collection and conversion effect.

[0131] The perovskite top cell and crystalline silicon bottom cell in the tandem solar cell provided in this application have good complementary spectral responses and achieve synergistic effects. There is almost no parasitic absorption in the wavelength range exceeding 750nm, which gives the tandem solar cell a better passivation effect and current gain, thereby improving the photoelectric conversion efficiency of the tandem solar cell.

[0132] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The directional terms "inner" and "outer" refer to the inside or outside relative to the outline of the component itself. For example, if a device in the drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0133] It should also be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this application refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0134] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0135] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A tandem solar cell, characterized in that, It includes a perovskite top cell, an interface layer (200), and a crystalline silicon bottom cell stacked sequentially from the front to the back. The crystalline silicon bottom cell comprises, from front to back, a first passivation layer (304), a second passivation layer (303), a silicon substrate (300), a silicon oxide layer (301), a doped polycrystalline silicon layer (302), a transparent conductive layer (305), and a back metal electrode (306) stacked sequentially. The first passivation layer (304) includes at least one of a doped amorphous silicon layer, a doped nanocrystalline silicon layer, or a doped microcrystalline silicon layer; The second passivation layer (303) is an intrinsic amorphous silicon layer.

2. The tandem solar cell according to claim 1, characterized in that, The silicon substrate (300) is a p-type silicon substrate or an n-type silicon substrate.

3. The tandem solar cell according to claim 2, characterized in that, The first passivation layer (304) is p-type or n-type doped.

4. The tandem solar cell according to claim 2, characterized in that, The doped polycrystalline silicon layer (302) is p-type or n-type.

5. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the first passivation layer (304) is 5nm~35nm.

6. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the second passivation layer (303) is 4nm~10nm.

7. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the silicon oxide layer (301) is 1 nm to 5 nm.

8. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the doped polycrystalline silicon layer (302) is 10nm~130nm.

9. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the transparent conductive layer (305) is 10nm~130nm.

10. The tandem solar cell according to any one of claims 1-4, characterized in that, The thickness of the interface layer (200) is 10nm~130nm.

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