Perovskite solar cell and preparation method thereof, photovoltaic module

Abstract

The application relates to the technical field of solar cells, in particular to a perovskite solar cell, a preparation method thereof and a photovoltaic module. The perovskite solar cell provided by the embodiment of the application comprises a buffer layer, the buffer layer is arranged between an electrode structure and a carrier functional layer, and the buffer layer comprises a polyethylene imine derivative. The long-chain structure of the polyethylene imine derivative can physically block high-energy particles in a sputtering process, significantly reduce the physical damage to an organic charge transport layer and a perovskite active layer of an underlying layer, eliminate the negative influence of transparent electrode preparation, improve the transmission and extraction of electrons in the perovskite solar cell, improve the photoelectric conversion efficiency and stability of the perovskite solar cell, and reduce the photoelectric conversion efficiency decay rate.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to perovskite solar cells and their fabrication methods, as well as photovoltaic modules. Background Technology

[0002] Perovskite solar cells have garnered significant attention over the past decade due to their superior photovoltaic performance, with their photoelectric conversion efficiency rapidly increasing to 25.7%, making them one of the most promising thin-film photovoltaic technologies. Semi-transparent perovskite solar cells, combining light collection and photoelectric conversion functions, can be directly attached to building surfaces, providing power without obscuring the building's original appearance, making them ideal for building-integrated photovoltaics (BIPV) applications. Furthermore, semi-transparent perovskite solar cells can be used in series-decoupled tandem solar cells; by combining them with narrow bandgap cells, they can break through the theoretical efficiency limit of single-junction solar cells, further enhancing photoelectric conversion performance. The photoelectric performance of the transparent electrode is one of the key factors limiting the efficiency of semi-transparent perovskite solar cells. However, the perovskite material in perovskite solar cells is temperature-sensitive; therefore, the transparent top electrode must be deposited under low-temperature conditions. Currently, common transparent electrode materials include metal nanowires, carbon materials (carbon nanotubes, graphene), ultrathin metal films, transparent conductive polymers, and transparent conductive oxides (TCOs). Among these, transparent conductive oxides (TCOs) have become the most widely used transparent electrode material due to their excellent electron transport and optical transmittance properties. However, TCO electrodes are usually prepared by sputtering. The sputtering method uses high-energy deposition particles produced by high-energy deposition technology, which can easily cause physical damage to the underlying organic charge transport layer and perovskite active layer, thereby affecting the overall performance and stability of perovskite solar cells and limiting the large-scale application of semi-transparent perovskite solar cells.

[0003] Current solutions to the above problems include, on the one hand, using industrially compatible bath copper ether (BCP) thermal evaporation to replace the ALD-SnOx buffer layer, resulting in a 20mV open-circuit voltage gain in the solar cell and a higher current density due to reduced parasitic absorption; on the other hand, using a ZnO / BCP / Ag multilayer buffer layer, which shows better performance than a single-layer ZnO buffer in eliminating the negative effects of sputtered electrodes. However, the above solutions cannot effectively eliminate the negative effects of preparing transparent electrodes, which is detrimental to electron transport and extraction in the solar cell and the stability of the device.

[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. Summary of the Invention

[0005] This application provides a perovskite solar cell and its preparation method, as well as a photovoltaic module, to solve or alleviate the technical problems mentioned above, such as the inability to effectively eliminate the negative impact of transparent electrode preparation, which is detrimental to electron transport and extraction in solar cells and the stability of the device.

[0006] The first aspect of this application provides a perovskite solar cell, including a buffer layer disposed between an electrode structure and a carrier functional layer, wherein the buffer layer includes a polyethyleneimine derivative.

[0007] The buffer layer in the perovskite solar cell provided in this application includes a polyethyleneimine derivative. The long-chain structure of the polyethyleneimine derivative can physically block high-energy particles during sputtering, significantly reducing physical damage to the underlying organic charge transport layer and perovskite active layer, eliminating the negative impact of electrode structure preparation; improving electron transport and extraction in the perovskite solar cell, increasing the photoelectric conversion efficiency and stability of the perovskite solar cell, and reducing the photoelectric conversion efficiency decay rate.

[0008] Optionally, the polyethyleneimine derivative includes at least one of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine.

[0009] The embodiments of this application utilize polyethyleneimine derivatives, including at least one of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine. The primary, secondary, and tertiary amine groups on the molecular chains of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine exhibit basic and cationic activity. Through amine reaction modification, they demonstrate good affinity and adsorption for anionic substances, promoting electron transport and extraction, and enhancing photocurrent. This further improves the photoelectric conversion efficiency of perovskite solar cells and reduces the photoelectric conversion efficiency decay rate.

[0010] Optionally, the degree of ethoxylation of the ethoxylated polyethyleneimine is 30%-80%.

[0011] Optionally, the thickness of the buffer layer is 50nm-80nm.

[0012] The buffer layer provided in this application embodiment has a thickness of 50nm-80nm, which can further optimize the protective effect and electron transport efficiency of the buffer layer, thereby increasing the initial photoelectric conversion efficiency of the perovskite solar cell to 31.15%-31.59%, enhancing the operational stability of the perovskite solar cell device, and achieving a photoelectric conversion efficiency decay rate of less than 13% after 300 hours of operation.

[0013] Optionally, the charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

[0014] The second aspect of this application provides a method for fabricating a perovskite solar cell, comprising the following steps:

[0015] A sputtering protective layer is formed on the surface of the charge carrier functional layer; After preparing a solution of polyethyleneimine derivative, a film is formed on the surface of the charge carrier functional layer, and a buffer layer is formed after annealing. An electrode structure is formed on the surface of the buffer layer.

[0016] The perovskite solar cell fabrication method provided in this application can form a dual protection layer of sputtering protection and buffer layer, further isolating sputtering damage, while also constructing an efficient electron transport channel; improving electron transport and extraction in perovskite solar cells, and enhancing the photoelectric conversion efficiency and stability of perovskite solar cells.

[0017] Optionally, the polyethyleneimine derivative is prepared by adding the polyethyleneimine derivative to an alcohol solvent.

[0018] The embodiments of this application use alcohol solvents, which can better dissolve polyethyleneimine derivatives, resulting in a solution with good film uniformity and avoiding the impact of solvent residue on the performance of perovskite solar cell devices.

[0019] Optionally, the mass concentration of the polyethyleneimine derivative in the solution is 0.01wt%-0.1wt%.

[0020] The solution provided in this application has a polyethyleneimine derivative concentration of 0.01wt%-0.1wt%, which can provide a buffer layer with uniform thickness and a dense structure, providing not only protection but also not affecting optical transmittance.

[0021] Optionally, the mass concentration of the polyethyleneimine derivative in the solution is 0.02wt%-0.06wt%.

[0022] Optionally, the annealing temperature is 90℃-120℃, and the annealing time is 1min-5min.

[0023] This application provides a method for preparing an ethoxylated polyethyleneimine solution and placing it on the surface of a sputtering protective layer for film formation. After annealing at 90°C-120°C for 1-5 minutes, a buffer layer is formed. This not only promotes the regular arrangement of the buffer layer molecules but also enhances the interfacial bonding with the sputtering protective layer and the transparent conductive layer, reduces interfacial recombination, and improves electron transport efficiency.

[0024] Optionally, the charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

[0025] A third aspect of this application provides a photovoltaic module, including a perovskite solar cell as described above or a perovskite solar cell prepared by the method described above.

[0026] The photovoltaic modules provided in this application have high photoelectric conversion efficiency and improved long-term operational reliability, and can be better compatible with various application scenarios such as building-integrated photovoltaics and tandem photovoltaic systems.

[0027] The embodiments of this application employing the above-described technical solution may have the following advantages: The buffer layer in the perovskite solar cell provided in this application includes a polyethyleneimine derivative. The long-chain structure of the polyethyleneimine derivative can physically block high-energy particles during sputtering, significantly reducing physical damage to the underlying organic charge transport layer and perovskite active layer, eliminating the negative impact of electrode structure preparation; improving electron transport and extraction in the perovskite solar cell, increasing the photoelectric conversion efficiency and stability of the perovskite solar cell, and reducing the photoelectric conversion efficiency decay rate.

[0028] The perovskite solar cell fabrication method provided in this application can form a dual protection layer of sputtering protection and buffer layer, further isolating sputtering damage, while also constructing an efficient electron transport channel; improving electron transport and extraction in perovskite solar cells, and enhancing the photoelectric conversion efficiency and stability of perovskite solar cells. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the structure of the silicon-based battery provided in the embodiments of this application.

[0032] Explanation of reference numerals in the attached figures: Figure 1 In the middle: silicon substrate 100, hole transport layer 110, perovskite layer 120, passivation modification layer 130, electron transport layer 140, sputtering protection layer 150, buffer layer 160, transparent conductive layer 170, electrode 180, antireflection layer 190.

[0033] Figure 2 In the middle: silicon substrate 100, back silver grid layer 10, back transparent conductive oxide layer 11, back n-type doped amorphous silicon (a-Si:H) layer 12, back intrinsic amorphous silicon (a-Si:H) layer 13, N-type crystalline silicon substrate 14, front intrinsic amorphous silicon (a-Si:H) layer 15, front p-type doped amorphous silicon (a-Si:H) layer 16, front transparent conductive oxide layer 17. Detailed Implementation

[0034] 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 features of this application and its embodiments can be combined with each other.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] This application involves numerical intervals (i.e., numerical ranges). Unless otherwise specified, the distribution of selectable numerical values ​​within a 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 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.

[0039] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. 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.

[0040] This application provides a perovskite solar cell, including a buffer layer disposed between an electrode structure and a carrier functional layer, wherein the buffer layer includes a polyethyleneimine derivative.

[0041] The buffer layer in the perovskite solar cell provided in this application includes a polyethyleneimine derivative. The long-chain structure of the polyethyleneimine derivative can physically block high-energy particles during sputtering, significantly reducing physical damage to the underlying organic charge transport layer and perovskite active layer, eliminating the negative impact of electrode structure preparation; improving electron transport and extraction in the perovskite solar cell, increasing the photoelectric conversion efficiency and stability of the perovskite solar cell, and reducing the photoelectric conversion efficiency decay rate.

[0042] In an optional embodiment, the polyethyleneimine derivative includes at least one of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine.

[0043] The embodiments of this application utilize polyethyleneimine derivatives, including at least one of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine. The primary, secondary, and tertiary amine groups on the molecular chains of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine exhibit basic and cationic activity. Through amine reaction modification, they demonstrate good affinity and adsorption for anionic substances, promoting electron transport and extraction, and enhancing photocurrent. This further improves the photoelectric conversion efficiency of perovskite solar cells and reduces the photoelectric conversion efficiency decay rate.

[0044] In an optional embodiment, the polyethyleneimine derivative is preferably ethoxylated polyethyleneimine.

[0045] In an optional embodiment, the ethoxylated polyethyleneimine has the following structural formula:

[0046] This application uses ethoxylated polyethyleneimine. The primary, secondary, and tertiary amine groups on the ethoxylated polyethyleneimine molecular chain are basic and cationic, exhibiting good affinity and adsorption for anionic substances. This promotes electron transport and extraction, increases photocurrent, and further improves the photoelectric conversion efficiency of perovskite solar cells while reducing the photoelectric conversion efficiency decay rate.

[0047] In an optional embodiment, the degree of ethoxylation of the ethoxylated polyethyleneimine is optionally 30%-80% (exemplary, such as 30%, 40%, 50%, 60%, 70%, 80%, etc.).

[0048] In an optional embodiment, the thickness of the buffer layer is 50nm-80nm (exemplary, such as 50nm, 60nm, 70nm, 80nm, etc.).

[0049] In an optional embodiment, the charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

[0050] The buffer layer provided in this embodiment is disposed between the electrode structure and the electron transport layer. The thickness of the buffer layer is 50nm-80nm, which can further optimize the protective effect and electron transport efficiency of the buffer layer, thereby increasing the initial photoelectric conversion efficiency of the perovskite solar cell to 31.15%-31.59%, enhancing the operational stability of the perovskite solar cell device, and reducing the photoelectric conversion efficiency decay rate to less than 13% after 300 hours of operation.

[0051] This application provides a method for fabricating a perovskite solar cell, comprising the following steps: A sputtering protective layer is formed on the surface of the charge carrier functional layer; After preparing a solution of polyethyleneimine derivative, a film is formed on the surface of the charge carrier functional layer, and a buffer layer is formed after annealing. An electrode structure is formed on the surface of the buffer layer.

[0052] In an optional embodiment, the electrode structure includes a transparent conductive layer.

[0053] In an optional embodiment, the film formation process of preparing a solution of the polyethyleneimine derivative on the surface of the charge carrier functional layer includes: preparing a solution of the polyethyleneimine derivative and then spin-coating it onto the sputtering protective layer at a spin-coating speed of 4000-5000 r / s (exemplary, such as 4000 r / s, 4500 r / s, 5000 r / s, etc.) for 10-30 s (exemplary, such as 10 s, 15 s, 20 s, 25 s, 30 s). Alternatively, a film-forming process can be performed on the sputtering protective layer by preparing a solution of the polyethyleneimine derivative and applying it with a coating height of 50-200 μm (exemplary values ​​such as 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 2000 μm, etc.) and a coating rate of 10-20 mm / s (exemplary values ​​such as 10 mm / s, 15 mm / s, 20 mm / s, etc.).

[0054] The perovskite solar cell fabrication method provided in this application can form a dual protection layer of sputtering protection and buffer layer, further isolating sputtering damage, while also constructing an efficient electron transport channel; improving electron transport and extraction in perovskite solar cells, and enhancing the photoelectric conversion efficiency and stability of perovskite solar cells.

[0055] In an optional embodiment, the carrier functional layer includes at least one of a hole transport layer or an electron transport layer.

[0056] In an optional embodiment, the polyethyleneimine derivative is prepared by adding the polyethyleneimine derivative to an alcohol solvent.

[0057] The embodiments of this application use alcohol solvents, which can better dissolve polyethyleneimine derivatives, resulting in a solution with good film uniformity and avoiding the impact of solvent residue on the performance of perovskite solar cell devices.

[0058] In an optional embodiment, the mass concentration of the polyethyleneimine derivative in the solution is 0.01wt%-0.1wt% (exemplary values ​​such as 0.01wt%, 0.015wt%, 0.02wt%, 0.025wt%, 0.03wt%, 0.035wt%, 0.04wt%, 0.045wt%, 0.05wt%, 0.055wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, etc.).

[0059] In an optional embodiment, the ethoxylated polyethyleneimine is added to an alcohol solvent to prepare a solution.

[0060] The embodiments of this application use alcohol solvents, which can better dissolve ethoxylated polyethyleneimine, resulting in a solution with good film uniformity and avoiding the impact of solvent residue on the performance of perovskite solar cell devices.

[0061] In an optional embodiment, the alcohol solvent includes isopropanol.

[0062] In an optional embodiment, the ethoxylated polyethyleneimine is added to an alcohol solvent to prepare an isopropanol solution of the ethoxylated polyethyleneimine.

[0063] In an optional embodiment, the mass concentration of ethoxylated polyethyleneimine in the isopropanol solution of the ethoxylated polyethyleneimine is 0.01wt%-0.1wt% (exemplary values ​​such as 0.01wt%, 0.015wt%, 0.02wt%, 0.025wt%, 0.03wt%, 0.035wt%, 0.04wt%, 0.045wt%, 0.05wt%, 0.055wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, etc.).

[0064] In an optional embodiment, the mass concentration of ethoxylated polyethyleneimine in the isopropanol solution of the ethoxylated polyethyleneimine is 0.02wt%-0.06wt% (exemplary values ​​such as 0.02wt%, 0.025wt%, 0.03wt%, 0.035wt%, 0.04wt%, 0.045wt%, 0.05wt%, 0.055wt%, 0.06wt%, etc.).

[0065] The mass concentration of ethoxylated polyethyleneimine in the solution provided in this application embodiment is 0.01wt%-0.1wt%, preferably 0.02wt%-0.06wt%, which can provide a buffer layer with uniform thickness and dense structure, which not only has a protective effect but also does not affect optical transmittance.

[0066] In an optional embodiment, the annealing temperature is 90℃-120℃ (exemplary, such as 90℃, 100℃, 110℃, 120℃, etc.), and the annealing time is 1min-5min (exemplary, such as 1min, 2min, 3min, 4min, 5min, etc.).

[0067] This application provides a method for preparing an ethoxylated polyethyleneimine solution and placing it on the surface of a sputtering protective layer for film formation. After annealing at 90°C-120°C for 1-5 minutes, a buffer layer is formed. This not only promotes the regular arrangement of the buffer layer molecules but also enhances the interfacial bonding with the sputtering protective layer and the transparent conductive layer, reduces interfacial recombination, and improves electron transport efficiency.

[0068] In an optional embodiment, the charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

[0069] In an optional embodiment, the method for fabricating the perovskite solar cell includes the following steps: S1. Deposit nickel oxide on a silicon substrate to form a hole transport layer with a thickness of 10-15 nm (exemplary, such as 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, etc.); S2. Add Cs with a molar concentration of 1-2 mol / L (exemplary concentrations include 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L, etc.). 0.05 MA 0.15 FA 0.8 Pb(I 0.75 Br 0.25A perovskite precursor solution of 3 is placed on the surface of the hole transport layer for film formation; a perovskite thin film is formed, and a perovskite layer with a thickness of 400-600 nm (exemplary, such as 400 nm, 500 nm, 600 nm, etc.) is formed by annealing; the perovskite precursor solution uses a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide, and the volume ratio of N,N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is (3-5):1 (exemplary, such as 3:1, 4:1, 5:1, etc.). S3. Deposit phenylethyl ammonium iodide on the perovskite layer to form a passivation modification layer with a thickness of 1-5 nm (exemplary, such as 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, etc.); S4. Fullerene is deposited on the passivation modification layer by thermal evaporation to form an electron transport layer with a thickness of 20-40 nm (exemplary, such as 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, etc.); S5. Tin dioxide is deposited on the electron transport layer using atomic layer deposition to form a sputtering protective layer with a thickness of 10-30 nm (exemplary, such as 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, etc.); S6. A solution of ethoxylated polyethyleneimine in isopropanol with a mass concentration of 0.01wt%-0.1wt% (exemplary concentrations such as 0.01wt%, 0.015wt%, 0.02wt%, 0.025wt%, 0.03wt%, 0.035wt%, 0.04wt%, 0.045wt%, 0.05wt%, 0.055wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, etc.) is spin-coated onto the sputtering protective layer at a spin-coating speed of 4000-5000 r / s (exemplary concentrations such as 4000 r / s, 4500 r / s, 5000 r / s, etc.) for 10-30 s (exemplary concentrations such as 10 s, 15 s, 20 s, 25 s, 30 s, etc.) to form a film, or by using... After preparing a solution of polyethyleneimine derivative, a film is formed on the sputtering protective layer using a coating process with a coating height of 50-200 μm (exemplary, such as 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 2000 μm, etc.) and a coating rate of 10-20 mm / s (exemplary, such as 10 mm / s, 15 mm / s, 20 mm / s, etc.). After the film formation process, the film is annealed at 90℃-120℃ (exemplary, such as 90℃, 100℃, 110℃, 120℃, etc.) for 1 min-5 min (exemplary, such as 1 min, 2 min, 3 min, 4 min, 5 min, etc.) to form a buffer layer with a thickness of 50 nm-80 nm (exemplary, such as 50 nm, 60 nm, 70 nm, 80 nm, etc.). S7. IZO is sputtered onto the sputtering protective layer using a sputtering instrument to form a transparent conductive layer with a thickness of 50-90nm (exemplary, such as 50nm, 60nm, 70nm, 80nm, 90nm, etc.); S8. Silver is deposited on the antireflection layer by thermal evaporation to form an electrode with a thickness of 200-600nm (exemplary, such as 200nm, 300nm, 400nm, 500nm, 600nm, etc.); S9. Magnesium fluoride is deposited on the transparent conductive layer by thermal evaporation to form an antireflection layer with a thickness of 80-120nm (exemplary, such as 80nm, 90nm, 100nm, 110nm, 120nm, etc.).

[0070] like Figure 2 As shown, the silicon-based solar cell includes, from bottom to top, a back silver grid layer 10, a back transparent conductive oxide layer 11, a back n-type doped amorphous silicon (a-Si:H) layer 12, a back intrinsic amorphous silicon (a-Si:H) layer 13, an N-type crystalline silicon substrate 14, a front intrinsic amorphous silicon (a-Si:H) layer 15, a front p-type doped amorphous silicon (a-Si:H) layer 16, and a front transparent conductive oxide layer 17.

[0071] In an optional embodiment, the method for fabricating the silicon-based solar cell includes: using a chemical vapor deposition process, depositing amorphous silicon (a-Si:H) on the first and second surfaces of an N-type crystalline silicon substrate 14 at a deposition temperature of 180-210℃ (exemplary, such as 180℃, 190℃, 200℃, 205℃, 210℃, etc.), respectively, to obtain a front intrinsic amorphous silicon (a-Si:H) layer 15 and a back intrinsic amorphous silicon (a-Si:H) layer 15. 13; Using a chemical vapor deposition process, amorphous silicon (a-Si:H) is deposited on the surface of the front intrinsic amorphous silicon (a-Si:H) layer 15 at a deposition temperature of 180-210℃ (exemplary, such as 180℃, 190℃, 200℃, 205℃, 210℃, etc.) to obtain a front p-type doped amorphous silicon (a-Si:H) layer 16; Using a chemical vapor deposition process, amorphous silicon (a-Si:H) is deposited on the surface of the front intrinsic amorphous silicon (a-Si:H) layer 15 at a deposition temperature of 180-210℃ (exemplary, such as 180℃, 190℃, 200℃, 205℃, 210℃, etc.) to obtain a front p-type doped amorphous silicon (a-Si:H) layer 16; Amorphous silicon (a-Si:H) is deposited on the surface of the intrinsic amorphous silicon (a-Si:H) layer 13 on the back side at deposition temperatures of 200℃, 205℃, 210℃, etc., to obtain the n-type doped amorphous silicon (a-Si:H) layer 12 on the back side; then, using physical vapor deposition, a deposition temperature of 70-90℃ (exemplary, such as 70℃, 75℃, 80℃, 85℃, 90℃) is used on the n-type doped amorphous silicon (a-Si:H) layer 12 on the back side and the p-type doped amorphous silicon (a-Si:H) layer on the front side, respectively. ITO (indium tin oxide) is deposited on the surface of the doped amorphous silicon (a-Si:H) layer 16 to obtain a back transparent conductive oxide layer 11 and a front transparent conductive oxide layer 17, respectively. Ag is deposited on the surface of the back transparent conductive oxide (TCO) layer 11 using physical vapor deposition at a deposition temperature of 80-110℃ (exemplary, such as 80℃, 85℃, 90℃, 100℃, 105℃, 110℃, etc.) to obtain a back silver gate layer 10.

[0072] In an optional embodiment, the thickness of the back silver grid layer 10 is 10-20 μm (exemplary, such as 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, etc.).

[0073] In an optional embodiment, the thickness of the back transparent conductive oxide layer 11 is 80-100 nm (exemplary, such as 80 nm, 90 nm, 100 nm, etc.).

[0074] In an optional embodiment, the thickness of the back n-type doped amorphous silicon (a-Si:H) layer 12 is 5-20 nm (exemplary, such as 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, etc.).

[0075] In an optional embodiment, the thickness of the back intrinsic amorphous silicon (a-Si:H) layer 13 is 2-10 nm (exemplary, such as 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc.).

[0076] In an optional embodiment, the thickness of the N-type crystalline silicon substrate 14 is 100-200 μm (exemplary, such as 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, etc.).

[0077] In an optional embodiment, the thickness of the front intrinsic amorphous silicon (a-Si:H) layer 15 is 2-10 nm (exemplary, such as 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc.).

[0078] In an optional embodiment, the thickness of the front p-type doped amorphous silicon (a-Si:H) layer 16 is 5-20 nm (exemplary, such as 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, etc.).

[0079] In an optional embodiment, the thickness of the front transparent conductive oxide layer 17 is 70-120 nm (exemplary, such as 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, etc.).

[0080] This application provides a photovoltaic module, including a perovskite solar cell as described above or a perovskite solar cell prepared by the method described above.

[0081] The photovoltaic modules provided in this application have high photoelectric conversion efficiency and improved long-term operational reliability, and can be better compatible with various application scenarios such as building-integrated photovoltaics and tandem photovoltaic systems.

[0082] The following section will present performance tests on the structure or fabrication method of the perovskite solar cell provided in the embodiments of this application, as well as related comparative examples.

[0083] Group 1 Experiment The first set of experiments provides Examples 1-5; Examples 1-5 provide a film-forming treatment by spin-coating isopropanol solutions of ethoxylated polyethyleneimine with different mass concentrations and different degrees of ethoxylation onto a sputtered protective layer to form a buffer layer.

[0084]

Example 1

[0085] This application provides a method for fabricating a perovskite solar cell, comprising the following steps: S1. Deposit nickel oxide on silicon substrate 100 to form hole transport layer 110 with a thickness of 10 nm; S2. Cs with a molar concentration of 1.7 mol / L 0.05 MA 0.15 FA 0.8 Pb(I 0.75 Br 0.25 The perovskite precursor solution of 3 was placed on the surface of the hole transport layer for film formation; a perovskite thin film was formed, and a perovskite layer with a thickness of 600 nm was formed by annealing at 110 °C for 15 min. S3. Phenethyl ammonium iodide is deposited on the perovskite layer to form a passivation modification layer 130 with a thickness of 2 nm; S4. Fullerene is deposited on the passivation modification layer by thermal evaporation to form an electron transport layer 140 with a thickness of 25 nm; S5. Tin dioxide is deposited on the electron transport layer using atomic layer deposition to form a sputtering protective layer 150 with a thickness of 20 nm; S6. A 0.025 wt% isopropanol solution of ethoxylated polyethyleneimine is spin-coated onto a sputtering protective layer at a spin-coating speed of 4000 r / s for 20 s to form a film, and then annealed at 100 °C for 2 min to form a buffer layer 160 with a thickness of 60 nm; the degree of ethoxylation of the ethoxylated polyethyleneimine is 80%. S7. IZO is sputtered onto the buffer layer using a sputtering instrument to form a transparent conductive layer 170 with a thickness of 50 nm; S8. Silver is deposited on the transparent conductive layer by thermal evaporation to form an electrode 180 with a thickness of 400 nm; S9. Magnesium fluoride is deposited on the metal electrode by thermal evaporation to form an antireflection layer 190 with a thickness of 100 nm.

[0086] The perovskite precursor solution in S2 uses a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), with a volume ratio of 4:1.

[0087] like Figure 2As shown, the silicon-based solar cell 100 includes, from bottom to top, a back silver grid layer 10, a back transparent conductive oxide layer 11, a back n-type doped amorphous silicon (a-Si:H) layer 12, a back intrinsic amorphous silicon (a-Si:H) layer 13, an N-type crystalline silicon substrate 14, a front intrinsic amorphous silicon (a-Si:H) layer 15, a front p-type doped amorphous silicon (a-Si:H) layer 16, and a front transparent conductive oxide layer 17.

[0088] The method for fabricating the silicon substrate solar cell includes: depositing amorphous silicon (a-Si:H) on the first and second surfaces of an N-type crystalline silicon substrate 14 at a deposition temperature of 200°C using a chemical vapor deposition process, to obtain a front intrinsic amorphous silicon (a-Si:H) layer 15 and a back intrinsic amorphous silicon (a-Si:H) layer 13; depositing amorphous silicon (a-Si:H) on the surface of the front intrinsic amorphous silicon (a-Si:H) layer 15 at a deposition temperature of 200°C using a chemical vapor deposition process, to obtain a front p-type doped amorphous silicon (a-Si:H) layer 16; and depositing amorphous silicon (a-Si:H) on the back intrinsic amorphous silicon substrate 15 at a deposition temperature of 200°C using a chemical vapor deposition process. Amorphous silicon (a-Si:H) is deposited on the surface of amorphous silicon (a-Si:H) layer 13 to obtain a back n-type doped amorphous silicon (a-Si:H) layer 12; ITO (indium tin oxide) is deposited on the surfaces of the back n-type doped amorphous silicon (a-Si:H) layer 12 and the front p-type doped amorphous silicon (a-Si:H) layer 16 at a deposition temperature of 80°C using physical vapor deposition to obtain a back transparent conductive oxide layer 11 and a front transparent conductive oxide layer 17, respectively; Ag is deposited on the surface of the back transparent conductive oxide (TCO) layer 11 at a deposition temperature of 100°C using physical vapor deposition to obtain a back silver gate layer 10. The back silver gate layer 10 has a thickness of 20 μm, the back transparent conductive oxide layer 11 has a thickness of 100 nm, the back n-type doped amorphous silicon (a-Si:H) layer 12 has a thickness of 10 nm, the back intrinsic amorphous silicon (a-Si:H) layer 13 has a thickness of 5 nm, the N-type crystalline silicon substrate 14 has a thickness of 120 μm, the front intrinsic amorphous silicon (a-Si:H) layer 15 has a thickness of 5 nm, the front p-type doped amorphous silicon (a-Si:H) layer 16 has a thickness of 10 nm, and the front transparent conductive oxide layer 17 has a thickness of 120 nm.

[0089]

Example 2

[0090] The specific content is as follows: S6. A 0.05 wt% isopropanol solution of ethoxylated polyethyleneimine is spin-coated onto the sputtering protective layer at a spin-coating speed of 4500 r / s for 20 s to form a film, and then annealed at 100 °C for 2 min to form a buffer layer with a thickness of 60 nm; the degree of ethoxylation of the ethoxylated polyethyleneimine is 80%.

[0091]

Example 3

[0092] The specific content is as follows: S6. A 0.05 wt% isopropanol solution of ethoxylated polyethyleneimine is coated onto a sputtering protective layer using a coating process with a coating height of 100 μm and a coating rate of 15 mm / s. The coating is then annealed at 100 °C for 2 min to form a buffer layer with a thickness of 60 nm on the sputtering protective layer. The degree of ethoxylation of the ethoxylated polyethyleneimine is 80%.

[0093]

Example 4

[0094] The specific content is as follows: S6. A 0.05 wt% isopropanol solution of ethoxylated polyethyleneimine is spin-coated onto the sputtering protective layer for 20 s at a spin-coating speed of 4500 r / s to form a film, and then annealed at 100 °C for 2 min to form a buffer layer with a thickness of 60 nm. The degree of ethoxylation of the ethoxylated polyethyleneimine is 30%.

[0095]

Example 5

[0096] The specific content is as follows: S6. A 0.05 wt% isopropanol solution of ethoxylated polyethyleneimine is spin-coated onto the sputtering protective layer at a spin-coating speed of 4500 r / s for 20 s to form a film, and then annealed at 100 °C for 2 min to form a buffer layer with a thickness of 60 nm. The degree of ethoxylation of the ethoxylated polyethyleneimine is 50%.

[0097] Control group experiment The control group experiment provides Comparative Example 1; Comparative Example 1 shows the use of a sputtering instrument to sputter IZO onto a sputtering protective layer to form a transparent conductive layer.

[0098] Comparative Example 1 The perovskite solar cell of Comparative Example 1 was prepared according to the preparation method of the perovskite solar cell provided in Example 1, except that: IZO was sputtered on the sputtering protective layer using a sputtering instrument to form a transparent conductive layer.

[0099] The specific content is as follows: S5. Tin dioxide is deposited on the electron transport layer using atomic layer deposition to form a sputtering protective layer with a thickness of 20 nm; S6. IZO is sputtered onto the sputtering protective layer using a sputtering instrument to form a transparent conductive layer with a thickness of 60 nm; S7. Magnesium fluoride is deposited on the transparent conductive layer by thermal evaporation to form an antireflection layer with a thickness of 100 nm; S8. Silver is deposited on the antireflection layer by thermal evaporation to form an electrode with a thickness of 400 nm.

[0100] Performance testing The perovskite solar cells provided in Examples 1-5 and Comparative Example 1 of this application were tested under standard test conditions to obtain the initial open-circuit voltage Voc, fill factor FF, short-circuit current density Jsc, and photoelectric conversion efficiency PCE of the perovskite solar cells after 300 hours of operation. The test results are shown in Table 1.

[0101] The fill factor (FF) used in this paper refers to the ratio of the actual maximum obtainable power (Pm or Vmp × Jmp) to the theoretical (not actually obtainable) power (Jsc × Voc). Therefore, FF can be determined by the following formula: FF = (Vmp × Jmp) / (Jsc × Voc), Where Jmp and Vmp represent the current density and voltage at the maximum power point (Pm), respectively, which is obtained by changing the resistance in the circuit until J×V reaches its maximum value; Jsc and Voc represent the short-circuit current and open-circuit voltage, respectively. The fill factor is a key parameter for evaluating perovskite solar cells. Commercial perovskite solar cells typically have a fill factor of approximately 60% or higher.

[0102] The open-circuit voltage (Voc) used in this paper is the potential difference between the anode and cathode of the device under conditions of no external load connection.

[0103] The short-circuit current (Isc) used in this article is the maximum current flowing through the output terminal of a photovoltaic cell or module when it is short-circuited (voltage V=0) under STC conditions.

[0104] The power conversion efficiency (PCE) of perovskite solar cells used in this article refers to the percentage of power converted from absorbed light into electrical energy, expressed as a percentage (%). The PCE of perovskite solar cells can be measured under standard test conditions (STC) with incident light irradiance (E: W / m²). 2 ) and the surface area (Ac:m) of perovskite solar cells 2 The STC is calculated by dividing by the point of maximum power (Pm). STC typically refers to the value at a temperature of 25°C and an irradiance of 100 W / m². 2 The spectrum of air quality 1.5 (AM1.5).

[0105] Table 1 provides test data for the perovskite solar cells provided in Examples 1-3 and Comparative Example 1.

[0106] Table 1

[0107] As shown in Table 1 above, the photoelectric conversion efficiency (PCE) of the solar cells provided in Examples 1-5 is 31.09%-31.59%, which is better than the PCE of the perovskite solar cell provided in Comparative Example 1 (30.93%). After 300 hours of operation, the PCE of the solar cells provided in Examples 1-5 is 27.52%-30.12%, with a PCE degradation rate of 3.8%-12.16%. After 300 hours of operation, the PCE of the perovskite solar cell provided in Comparative Example 1 is 25.54%, with a PCE degradation rate of 17.4%. Therefore, it can be seen that the process of spin-coating different mass concentrations of ethoxylated polyethyleneimine in isopropanol solution onto the sputtered protective layer to form a buffer layer in the solar cells provided in Examples 1-5 can improve the PCE of the solar cells, and the PCE degradation rate is less than 13%, which can significantly enhance the long-term operational stability of the solar cells.

[0108] This application embodiment can also provide a photovoltaic module (not shown), which includes the perovskite solar cell described above. The perovskite solar cell can be connected in series and / or in parallel with one or more other solar cells in a predetermined manner. Multiple cells can form a cell string, and adjacent cells can be connected together by string welding.

[0109] 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.

[0110] It should also be noted that, in this application, the terms "one embodiment," "another embodiment," or "embodiment," etc., 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.

[0111] 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.

[0112] 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 perovskite solar cell, characterized in that, It includes a buffer layer disposed between the electrode structure and the carrier functional layer, wherein the buffer layer includes a polyethyleneimine derivative.

2. The perovskite solar cell according to claim 1, characterized in that, The polyethyleneimine derivative includes at least one of methoxylated polyethyleneimine, ethoxylated polyethyleneimine, or propoxylated polyethyleneimine.

3. The perovskite solar cell according to claim 2, characterized in that, The degree of ethoxylation of the ethoxylated polyethyleneimine is 30%-80%.

4. The perovskite solar cell according to any one of claims 1-3, characterized in that, The thickness of the buffer layer is 50nm-80nm.

5. The perovskite solar cell according to any one of claims 1-3, characterized in that, The charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

6. A method for fabricating a perovskite solar cell, characterized in that, Includes the following steps: A sputtering protective layer is formed on the surface of the charge carrier functional layer; After preparing a solution of polyethyleneimine derivative, a film is formed on the surface of the charge carrier functional layer, and a buffer layer is formed after annealing. An electrode structure is formed on the surface of the buffer layer.

7. The method for preparing a perovskite solar cell according to claim 6, characterized in that, The polyethyleneimine derivative is prepared by adding the polyethyleneimine derivative to an alcohol solvent.

8. The method for preparing a perovskite solar cell according to claim 6 or 7, characterized in that, The mass concentration of the polyethyleneimine derivative in the solution is 0.01wt%-0.1wt%.

9. The method for preparing a perovskite solar cell according to claim 8, characterized in that, The mass concentration of the polyethyleneimine derivative in the solution is 0.02wt%-0.06wt%.

10. The method for preparing a perovskite solar cell according to any one of claims 6, 7, and 9, characterized in that, The annealing temperature is 90℃-120℃, and the annealing time is 1min-5min.

11. The method for preparing a perovskite solar cell according to claim 6, characterized in that, The charge carrier functional layer includes an electron transport layer, and the buffer layer is disposed between the electrode structure and the electron transport layer.

12. A photovoltaic module, characterized in that, This includes perovskite solar cells prepared by any one of claims 1-5 or by the method described in claim 6.

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