Crystalline silicon / perovskite laminated cell and preparation method thereof, photovoltaic module

Abstract

The present application belongs to the field of solar cells, and provides a crystalline silicon / perovskite stacked cell and a preparation method thereof, and a photovoltaic module. The method comprises the following steps: providing a crystalline silicon cell, the surface of which is a rough surface; covering the surface of the crystalline silicon cell with a perovskite solution to obtain a perovskite layer, wherein the perovskite solution comprises a perovskite material and nanoparticles. The method of the present application changes the crystallization mode of the perovskite layer by adding nanoparticles to the perovskite solution, which is beneficial to improving the photoelectric performance and yield of the crystalline silicon / perovskite stacked cell.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a crystalline silicon / perovskite stacked cell and a preparation method thereof, and a photovoltaic module. Background Art

[0002] Organic-inorganic hybrid perovskite materials have the advantages of high absorption coefficient, adjustable bandgap, long carrier diffusion length, high defect tolerance, simple preparation process, low material and preparation cost, and are considered to be the new materials closest to commercialization in the photovoltaic market in recent years. At present, single-junction perovskite cells have achieved a high photoelectric conversion efficiency, which is very close to the photoelectric conversion efficiency of mainstream crystalline silicon solar cells in the market.

[0003] Perovskite tandem solar cells have the advantages of high efficiency and low cost. With its outstanding advantages such as high efficiency, low cost and simple preparation process, it is considered to be one of the technologies that are expected to achieve large-scale ground photovoltaic applications. Crystalline silicon materials are the most promising tandem battery bottom cells because of their suitable band gap, low cost and highly mature market conditions and R&D system.

[0004] In the preparation process of crystalline silicon-perovskite tandem cells, the surface of the crystalline silicon cell is textured to form a pyramid structure of a certain size, which can greatly increase the optical absorption of the bottom cell. However, when preparing the film layer on the rough surface, since the crystallization method of the film layer is a process extending from the surface to the bottom, this will cause delamination of the bottom surface of the film layer, seriously affecting the performance and stability of the device.

[0005] 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

[0006] The embodiments of the present application provide a crystalline silicon / perovskite stacked cell and a preparation method thereof, and a photovoltaic module to solve or alleviate the above-mentioned problems of delamination of the bottom surface of the film layer when preparing the film layer on a rough surface, which seriously affects the performance and stability of the device.

[0007] In a first aspect of the embodiments of the present application, a method for preparing a crystalline silicon / perovskite stacked cell is provided. The method comprises the following steps: providing a crystalline silicon cell, wherein the surface of the crystalline silicon cell is a rough surface; and covering the surface of the crystalline silicon cell with a perovskite solution to obtain a perovskite layer, wherein the perovskite solution comprises a perovskite material and nanoparticles.

[0008] The method of the present application changes the crystallization mode during the formation of the perovskite layer by adding nanoparticles to the perovskite solution, thereby facilitating the improvement of the photoelectric performance and yield of the crystalline silicon / perovskite tandem battery.

[0009] Specifically, the crystalline silicon cell is used as the bottom cell of the crystalline silicon / perovskite stacked cell. The surface of the crystalline silicon cell has roughness. When the perovskite layer is prepared on the rough surface, nanoparticles are used as crystallization centers to obtain a perovskite layer with good film quality. This is because the contact between these nanoparticles and the perovskite material is defect-free contact, and almost no defect center is introduced. These nanoparticles can also be used as crystal nuclei to transition the film-forming crystallization mode of the perovskite layer from a state of surface supersaturation and preferential crystallization to a mode of crystal growth with nanoparticles as crystal nuclei. Since the nanoparticles are evenly distributed in the perovskite solution, the crystallization process of the perovskite layer is uniform, so that the bottom contact and stress of the perovskite layer are significantly improved, thereby improving the photoelectric performance and yield of the crystalline silicon / perovskite stacked cell.

[0010] According to an embodiment of the present application, a method for forming the perovskite layer includes sequentially performing an air knife blowing process and an annealing process.

[0011] According to an embodiment of the present application, the process of the air knife purging treatment includes purging with an inert gas knife, the gas pressure of the inert gas knife is 0.5-1.5 MPa, and the moving speed is 5-30 mm / s.

[0012] According to an embodiment of the present application, the annealing treatment is performed at a temperature of 60-150° C. for 5-20 minutes.

[0013] According to an embodiment of the present application, the nanoparticles include at least one of silicon dioxide, aluminum oxide, magnesium oxide, and silicon aluminum oxide.

[0014] According to an embodiment of the present application, in the perovskite solution, the concentration of the nanoparticles is 1×10 -7 -1mg / mL.

[0015] According to an embodiment of the present application, the particle size of the nanoparticles is 20-300 nm.

[0016] According to an embodiment of the present application, after providing a crystalline silicon cell and before covering the surface of the crystalline silicon cell with a perovskite solution, it further includes: depositing a first functional layer on the surface of the crystalline silicon cell, wherein the first functional layer includes a hole transport layer or an electron transport layer.

[0017] According to an embodiment of the present application, the roughness of the surface of the crystalline silicon cell is not less than 200 nm.

[0018] According to an embodiment of the present application, the crystalline silicon cell includes one of a heterojunction solar cell, a tunnel passivation contact cell, and a back contact solar cell.

[0019] According to an embodiment of the present application, the covering method includes spin coating, blade coating, evaporation, printing, spraying, spray drying or slit coating.

[0020] In the second aspect of the embodiment of the present application, a crystalline silicon / perovskite stacked cell is provided. The crystalline silicon / perovskite stacked cell includes a crystalline silicon cell, the crystalline silicon cell is used as the bottom cell of the crystalline silicon / perovskite stacked cell, and the surface of the crystalline silicon cell is a rough surface; a perovskite layer, the perovskite layer is located on the surface of the crystalline silicon cell, and the perovskite layer is obtained by covering the surface of the crystalline silicon cell with a perovskite solution, and the perovskite solution includes a perovskite material and nanoparticles. The photoelectric performance and yield of the crystalline silicon / perovskite stacked cell are both high. This is because the perovskite layer is obtained by covering the rough surface of the crystalline silicon cell with a perovskite solution, and the perovskite solution includes a perovskite material and nanoparticles. In this way, in the process of forming the perovskite layer, the nanoparticles improve the crystallization mode, improve the quality and yield of the perovskite layer; and improve the surface contact and stress between the perovskite layer and the crystalline silicon cell, thereby improving the performance and yield of the crystalline silicon / perovskite stacked cell.

[0021] According to an embodiment of the present application, a first functional layer is further provided between the crystalline silicon cell and the perovskite layer, and the first functional layer includes an electron transport layer or a hole transport layer.

[0022] According to a third aspect of the embodiment of the present application, a photovoltaic module is provided, wherein the photovoltaic module comprises a crystalline silicon / perovskite tandem cell prepared by the method described in the first aspect or comprises the crystalline silicon / perovskite tandem cell described in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0024] Figure 1 It is a schematic diagram of the structure of a crystalline silicon / perovskite tandem battery provided in an embodiment of the present application;

[0025] Figure 2 It is a fluorescence image of the perovskite layer of the crystalline silicon / perovskite tandem battery of Examples 6-8 and Comparative Example 2;

[0026] Figure 3 It is a microscopic morphology of the perovskite layer of the crystalline silicon / perovskite tandem battery of Example 7 and Comparative Example 2.

[0027] Description of reference numerals:

[0028] 1: back electrode; 2: second functional layer; 3: perovskite layer; 4: first functional layer; 5: crystalline silicon cell. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments 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 can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0031] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each 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 range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0034] In the preparation process of crystalline silicon-perovskite stacked cells, the surface of the crystalline silicon cell is textured to form a pyramid structure of a certain size, which greatly increases the optical absorption of the bottom cell. However, the rough surface structure introduces two problems at the same time: on the one hand, a thicker perovskite film needs to be prepared to cover the surface of the pyramid. On the other hand, in the process of thick film preparation, the crystallization process of the film layer extends from the surface to the bottom surface, and the evaporation of the solvent will cause the surface to crystallize faster, which will increase the stress of the film at the bottom contact point, leading to delamination of the bottom surface, thereby forming holes on the bottom surface, and ultimately affecting the contact between the bottom surface of the film layer and the surface of the crystalline silicon cell, resulting in a decrease in device performance.

[0035] Accordingly, in a first aspect of the embodiments of the present application, a method for preparing a crystalline silicon / perovskite stacked cell is provided. The method comprises the following steps: (1) providing a crystalline silicon cell, wherein the surface of the crystalline silicon cell is a rough surface; (2) covering the surface of the crystalline silicon cell with a perovskite solution to obtain a perovskite layer, wherein the perovskite solution comprises a perovskite material and nanoparticles.

[0036] The method of the embodiment of the present application changes the crystallization mode of the perovskite layer by adding nanoparticles to the perovskite solution, which is beneficial to improving the photoelectric performance and yield of the crystalline silicon / perovskite tandem battery.

[0037] Specifically, the crystalline silicon cell is used as the bottom cell of the crystalline silicon / perovskite stacked cell. The surface of the crystalline silicon cell has roughness. When the perovskite layer is prepared on the rough surface, nanoparticles are used as crystallization centers to obtain a perovskite layer with good film quality. This is because the contact between these nanoparticles and the perovskite material is defect-free contact and does not introduce defect centers. These nanoparticles can also be used as crystal nuclei to transition the film-forming crystallization mode of the perovskite layer from a state of surface supersaturation and preferential crystallization to a mode of crystal growth with nanoparticles as crystal nuclei. Since the nanoparticles are evenly distributed in the perovskite solution, the formation and crystallization process of the perovskite layer is carried out evenly, so that the bottom contact and stress of the perovskite layer are significantly improved, thereby improving the photoelectric performance and yield of the crystalline silicon / perovskite stacked cell.

[0038] According to an embodiment of the present application, step (1) provides a crystalline silicon cell, wherein the surface of the crystalline silicon cell is a rough surface.

[0039] The term rough surface refers to the fact that the surface of the crystalline silicon cell has a textured structure.

[0040] In some embodiments, the crystalline silicon cell includes one of a heterojunction solar cell, a tunnel passivation contact cell, and a back contact solar cell.

[0041] In some embodiments, the roughness of the surface of the crystalline silicon cell is not less than 200 nm.

[0042] Optionally, the roughness of the surface of the crystalline silicon cell is 200-3000 nm, for example, 200 nm, 300 nm, 480.1 nm, 600 nm, 800 nm, 1000 nm, 1585 nm, 2000 nm, 3000 nm, etc.

[0043] In some embodiments, the roughness of the surface of the crystalline silicon cell refers to the texture structure on the crystalline silicon surface and the height of the texture structure in the thickness direction of the crystalline silicon cell.

[0044] In some embodiments, the rough surface of the crystalline silicon cell refers to the surface of the crystalline silicon cell having a regular pyramid structure, an inverted pyramid structure, a black silicon structure, a sinusoidal structure, etc.

[0045] In some embodiments, after providing a crystalline silicon cell and before covering the surface of the crystalline silicon cell with a perovskite solution, the method further includes: depositing a first functional layer on the surface of the crystalline silicon cell, wherein the first functional layer includes a hole transport layer or an electron transport layer.

[0046] Optionally, the material of the hole transport layer includes nickel oxide (NiO2), cuprous oxide (Cu2O), molybdenum oxide (MoO3), copper iodide (CuI), redox graphene, poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA, poly (triaryl amine)), 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene (Spiro-OMeTAD), poly 3,4-ethylenedioxythiophene, polystyrene sulfonate (PEDOT:PSS), poly [bis (4-phenyl) (4-butylphenyl) amine] (Ploy-TPD), [2- (9H-carbazole-9-yl) ethyl] phosphonic acid, [2- (3,6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid One or more.

[0047] Optionally, the material of the electron transport layer includes titanium oxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), fullerene (C 60 ), graphene, and one or more of fullerene derivatives (PCBM).

[0048] Optionally, the thickness of the electron transport layer is 10-50 nm, for example, 10 nm, 12 nm, 30 nm, 50 nm, etc.

[0049] Optionally, the first functional layer is formed by electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition, spin coating, blade coating, etc.

[0050] In some embodiments, the thickness of the first functional layer is 0.1-50 nm, for example, 0.1 nm, 10 nm, 30 nm, 40 nm, 50 nm, etc.

[0051] According to an embodiment of the present application, step (2) covers the surface of the crystalline silicon cell with a perovskite solution to obtain a perovskite layer, wherein the perovskite solution includes a perovskite material and nanoparticles.

[0052] In some embodiments, the nanoparticles include at least one of silicon dioxide, aluminum oxide, magnesium oxide, and silicon aluminum oxide. These nanoparticles are insulating in nature and can be used as crystal nuclei to improve the film-forming crystallization process of the perovskite solution; these nanoparticles can also be used as light scatterers in the perovskite layer to promote the optical absorption of the stacked cell and further improve the optical performance of the stacked cell. In addition, insulating nanoparticles will hardly produce chaotic energy level arrangements and will hardly bring contact defects to the perovskite solution.

[0053] Optionally, the particle size of the nanoparticles is 20-300nm, such as 20nm, 30nm, 50nm, 100nm, 130nm, 180nm, 230nm, 270nm, 300nm, etc. In this way, smaller nanoparticles have a larger specific surface area, so that the crystal center has more active sites; nanoparticles make the diffusion path of solutes smaller, thereby promoting the growth of crystals and the uniform distribution of crystal centers; nanoparticles are also more evenly dispersed, thereby improving the stability of crystallization. Therefore, nanoparticles in the aforementioned range are conducive to obtaining a perovskite layer with better film quality.

[0054] It can be understood that these nanoparticles can have uniform particle sizes or non-uniform particle sizes, as long as their particle sizes meet the aforementioned ranges.

[0055] Optionally, the nanoparticles include one or more of solid particles, through-pore particles, mesoporous particles, and hollow particles.

[0056] In some embodiments, the concentration of the nanoparticles in the perovskite solution is 1×10 -7 -1mg / mL. This can avoid as much as possible the problems of excessive heterogeneous nucleation sites in the perovskite solution due to excessive concentration of nanoparticles, which leads to a significant decrease in the size of the perovskite grains; and the problems of too few nucleation sites introduced due to too low concentration of nanoparticles, which means that the main crystallization method is still from the surface to the bottom.

[0057] In some embodiments, in the perovskite solution, the perovskite material is a three-dimensional structure ABX3, A is a monovalent cation, including but not limited to cesium (Cs), rubidium (Rb), methylamine (CH3NH3), guanidine (CH2(NH2)2) one or more monovalent cation mixtures; B is a divalent cation, including but not limited to lead (Pb), copper (Cu), zinc (Zn), gallium (Ga), tin (Sn), calcium (Ca) one or more divalent cation mixtures; X is a monovalent anion, including but not limited to iodine (I), bromine (Br), chlorine (Cl), fluorine (F), thiocyanate ion (SCN), tetrafluoroborate (BF4 - ), hexafluorophosphate (PF6 - )formate (COO - ), acetate (CH3COO - ) is a mixture of one or more monovalent anions.

[0058] In some embodiments, in the perovskite solution, the solvent includes N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile (ACN), 2-methoxyethanol (2ME), 1,3-methyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), tetrahydrofuran (THF), N-methylpyrrolidone (NMP), etc.

[0059] In some embodiments, the coating method includes one or more of spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis, and slit coating.

[0060] Furthermore, the coating method is scraping, which includes filtering with a 200-400 μm oil filter, dripping the solution on the scraper head, and controlling the scraper moving speed to 5-30 mm / s and the scraper height to 50-150 μm.

[0061] In some embodiments, the method for forming the perovskite layer includes sequentially performing an air knife purging process and an annealing process. The air knife purging process is conducive to volatilizing the liquid in the perovskite solution to obtain a perovskite precursor film. The annealing process allows the adduct of a small amount of solvent molecules in the perovskite precursor film to release the coordinated solvent molecules and crystallize to form a perovskite layer.

[0062] Optionally, the process of the air knife purging treatment includes purging with an inert gas knife, the gas pressure of the inert gas knife is 0.5-1.5 MPa, and the moving speed is 5-30 mm / s.

[0063] Furthermore, the inert gas includes nitrogen.

[0064] Optionally, the annealing treatment is performed at a temperature of 60-150° C. and for a time of 5-20 min.

[0065] In some embodiments, the perovskite layer has a thickness of 1000-2000 nm, for example, 1000 nm, 1200 nm, 1500 nm, 2000 nm.

[0066] In some embodiments, the step further includes depositing a second functional layer.

[0067] Optionally, the second functional layer is an electron transport layer or a hole transport layer.

[0068] It is understood that if the first functional layer is an electron transport layer, the second functional layer is a hole transport layer. If the first functional layer is a hole transport layer, the second functional layer is an electron transport layer.

[0069] In some embodiments, the thickness of the second functional layer is 0.1-50 nm.

[0070] In some embodiments, the method further includes step (4) of sequentially forming a transparent electrode layer and an anti-reflection layer.

[0071] Optionally, the transparent electrode layer is indium zinc oxide (IZO), and the thickness of the transparent electrode layer is 60-90 nm.

[0072] Optionally, the anti-reflection layer includes MgF2, and the thickness of the anti-reflection layer is 100-150 nm.

[0073] In some embodiments, the step (5) of forming a back electrode is also included.

[0074] Optionally, the back electrode is selected from one of gold, palladium, silver, titanium, chromium, nickel, aluminum, copper, indium tin oxide (ITO), and indium zinc oxide (IZO).

[0075] In the second aspect of the embodiment of the present application, a crystalline silicon / perovskite stack cell is provided. The crystalline silicon / perovskite stack cell includes a crystalline silicon cell, the crystalline silicon cell is used as the bottom cell of the crystalline silicon / perovskite stack cell, and the surface of the crystalline silicon cell is a rough surface; a perovskite layer, the perovskite layer is located on the surface of the crystalline silicon cell, and the perovskite layer is obtained by covering the surface of the crystalline silicon cell with a perovskite solution, and the perovskite solution includes a perovskite material and nanoparticles. The photoelectric performance and yield of the crystalline silicon / perovskite stack cell are both high. This is because the perovskite layer is obtained by covering the rough surface of the crystalline silicon cell with a perovskite solution and drying it, and the perovskite solution includes a perovskite material and nanoparticles. In this way, in the process of forming the perovskite layer, the nanoparticles improve the crystallization mode, improve the quality and yield of the perovskite layer; and improve the surface contact and stress between the perovskite layer and the crystalline silicon cell, thereby improving the performance and yield of the crystalline silicon / perovskite stack cell.

[0076] In some embodiments, a first functional layer is further included between the crystalline silicon cell and the perovskite layer, and the first functional layer includes an electron transport layer or a hole transport layer.

[0077] In some embodiments, a second functional layer is further disposed on a side of the perovskite layer away from the first functional layer. The second functional layer includes an electron transport layer or a hole transport layer.

[0078] It is understood that if the first functional layer is an electron transport layer, the second functional layer is a hole transport layer. If the first functional layer is a hole transport layer, the second functional layer is an electron transport layer.

[0079] As an example, refer to Figure 1 The structure diagram of the crystalline silicon / perovskite stacked cell includes a crystalline silicon cell 5, a first functional layer 4, a perovskite layer 3, a second functional layer 2 and a back electrode 1 which are stacked in sequence.

[0080] In some embodiments, the yield of the crystalline silicon / perovskite tandem cell of the present application is improved by at least 20%.

[0081] In some embodiments, the photoelectric efficiency of the crystalline silicon / perovskite tandem cell of the present application is increased by at least 2%.

[0082] In other embodiments, the crystalline silicon / perovskite tandem cell further includes a crystalline silicon cell, a first functional layer, a perovskite layer, a second functional layer, a transparent electrode layer, an anti-reflection layer and a back electrode which are stacked in sequence.

[0083] Optionally, the transparent electrode layer includes indium zinc oxide (IZO), and the thickness of the transparent electrode layer is 60-90 nm.

[0084] Optionally, the anti-reflection layer includes MgF2, and the thickness of the anti-reflection layer is 100-150 nm.

[0085] According to a third aspect of the embodiment of the present application, a photovoltaic module is provided, wherein the photovoltaic module comprises a crystalline silicon / perovskite tandem cell prepared by the method described in the first aspect or comprises the crystalline silicon / perovskite tandem cell described in the second aspect.

[0086] In some embodiments, the photovoltaic module includes a plurality of solar cells connected in series and / or in parallel; wherein at least one solar cell is a crystalline silicon / perovskite tandem cell prepared by the method described in the first aspect as above or includes the crystalline silicon / perovskite tandem cell described in the second aspect. A plurality of crystalline silicon / perovskite tandem cells in series form a cell string, and adjacent crystalline silicon / perovskite tandem cells can be connected together by string welding.

[0087] In the fourth aspect of the embodiments of the present application, a photovoltaic system can be provided, including the photovoltaic components in any of the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The above photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components may form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box, and the junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0088] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0089] Example 1

[0090] (1) Preparation of bottom cell: Solar cells were prepared on n-type double-textured silicon wafers. Using plasma enhanced chemical vapor deposition (PECVD) technology, at a process temperature of 200°C, the first intrinsic silicon layer and the second intrinsic silicon layer were deposited on opposite sides of the wafer, and the n-type microcrystalline silicon layer was deposited on the side of the first intrinsic silicon layer away from the wafer; and the p-type microcrystalline silicon layer was deposited on the side of the second intrinsic silicon layer away from the wafer. The back contact of the silicon cell was prepared by stacking the first sputtered ITO conductive layer (80nm) and thermally evaporated Ag (150nm) on the side of the P-type microcrystalline silicon layer away from the wafer; and the second ITO conductive layer (80nm) was set on the side of the N-type microcrystalline silicon layer away from the wafer. The surface of the crystalline silicon cell has a velvet structure with a velvet roughness of 300nm.

[0091] (2) A layer of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid is deposited on the second ITO surface as a hole transport layer.

[0092] (3) Scrape the perovskite solution on the hole transport layer (scrape conditions are to filter with a 250μm oil filter, drop the solution on the scraper head, the scraper moves at a speed of 20mm / s, and the scraper height is 150μm), and blow the scraped perovskite solution layer with a N2 knife. The blowing pressure is 1Mpa and the moving speed is 20mm / s to form a perovskite precursor film. Then, place the cell with the perovskite precursor film on a substrate at 100°C for annealing to form a perovskite layer. The perovskite layer (FA 0.8 Cs 0.2 Pb(I 0.8 Br 0.2 )3) has a thickness of 1500 nm and a concentration of silicon dioxide in the perovskite solution of 1×10 -3 mg / mL, and the particle size of silica is 50 nm.

[0093] (4) A layer of fullerene (C 60 ), with a thickness of 12nm; a layer of tin dioxide (SnO2) with a thickness of 20nm is deposited by atomic layer deposition; an IZO (transparent electrode) layer with a thickness of 70nm is prepared by PVD, and a layer of MgF2 with a thickness of 120nm is thermally evaporated as an anti-reflection layer; finally, silver grid lines are evaporated on the surface to complete the preparation of crystalline silicon / perovskite stacked cells.

[0094] Embodiment 2-5

[0095] The crystalline silicon / perovskite stacked cells were prepared in the same manner as in Example 1, except that the concentrations of silicon dioxide in the perovskite solution were 1×10 -7 mg / mL, 1×10 -4 mg / mL, 0.01mg / mL and 1mg / mL.

[0096] Embodiment 6-8

[0097] A crystalline silicon / perovskite stacked cell was prepared in the manner of Example 1, except that the nanoparticles of the perovskite solution were aluminum oxide, and the concentrations of aluminum oxide were 0.01, 0.0001, and 0.000001 mg / mL, respectively, and the particle size of aluminum oxide was 30 nm.

[0098] Comparative Example 1

[0099] A crystalline silicon / perovskite stacked cell was prepared in the manner of Example 1, except that the particle size of silicon dioxide added to the perovskite solution was non-nano particle size, that is, the particle size was above 10 microns.

[0100] Comparative Example 2

[0101] A crystalline silicon / perovskite tandem cell was prepared in the manner of Example 7, except that no nanoparticles were added to the perovskite solution.

[0102] The crystalline silicon / laminated solar cells of the above-mentioned Examples 1-8 and Comparative Examples 1-2 were tested as follows, and the data are shown in Table 1:

[0103] (1) The IV test was performed using an LED light source at AM1.5G, the test temperature was 25°C, the scanning range was from an open circuit voltage of 2.05 V to -0.3 V, and the scanning speed was 0.04 V / s.

[0104] (2) Yield determination: The yield is calculated based on whether the device can achieve 95% of the highest efficiency in the same batch. If the device can achieve 95% of the highest efficiency, it is considered a good device. If it does not reach 95% of the highest efficiency, it is considered a defective device. 2,000 pieces of all devices are prepared for yield research.

[0105] Table 1

[0106]

[0107] By comparing Examples 1-8 and Comparative Examples 1-2, it can be seen that the performance of the crystalline silicon / perovskite tandem battery of Examples 1-8 is better than that of the crystalline silicon / perovskite tandem battery of Comparative Examples 1-2. This shows that when the perovskite layer is prepared on the rough surface, nanoparticles are used, and the contact between these nanoparticles and the perovskite material is defect-free contact, and no defect center is introduced. These nanoparticles can also be used as crystal nuclei to transition the film-forming crystallization mode of the perovskite layer from the state of surface supersaturation and preferential crystallization to the mode of crystal growth with nanoparticles as crystal nuclei. Since the nanoparticles are evenly distributed in the perovskite solution, the contact and stress at the bottom of the perovskite layer are significantly improved, thereby improving the photoelectric performance and yield of the crystalline silicon / perovskite tandem battery.

[0108] Figure 2 This is the fluorescence image of the perovskite layer prepared with different contents of aluminum oxide balls. Figure 2 Figure a (first horizontal row) is the fluorescence image of the perovskite layer of comparative example 2. Figure 2 Figure b (second row) is the fluorescence image of the perovskite layer of Example 6. Figure 2 Figure c (the third horizontal row) is a fluorescence image of the perovskite layer of Example 7. Figure 2 Figure d (the fourth horizontal row) is a fluorescence image of the perovskite layer of Example 8. From the figure, it can be seen that the perovskite layer obtained by the method of the present application has a better quality.

[0109] Figure 3 This is the microscopic morphology of the perovskite layer prepared by alumina balls with different contents. Figure 3 Figure a is a microscopic morphology of the perovskite layer of Example 7, and the roughness of the surface of the crystalline silicon cell includes 1585nm and 480.1nm; Figure 3 Figure b is a microscopic morphology of the perovskite layer of Example 2. From the figure, it can be seen that the addition of aluminum oxide nanospheres significantly improves the bottom surface morphology and increases the degree of bottom surface adhesion.

[0110] It should also be noted that the "some embodiments", "other embodiments", "embodiments", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing 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 conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0111] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0112] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a crystalline silicon / perovskite tandem battery, characterized in that: The following steps are involved: Providing a crystalline silicon cell, wherein the surface of the crystalline silicon cell is a rough surface; Covering the surface of the crystalline silicon cell with a perovskite solution to obtain a perovskite layer, wherein the perovskite solution includes a perovskite material and nanoparticles; The nanoparticles include at least one of silicon dioxide, aluminum oxide, magnesium oxide, and silicon aluminum oxide; In the perovskite solution, the concentration of the nanoparticles is 1×10 -7 -1mg / mL; The particle size of the nanoparticles is 20-300 nm.

2. The preparation method according to claim 1, characterized in that: The method of forming the perovskite layer includes sequentially performing an air knife purging process and an annealing process.

3. The preparation method according to claim 2, characterized in that: The process of the air knife purging treatment includes purging with an inert gas knife, the gas pressure of the inert gas knife is 0.5-1.5MPa, and the moving speed is 5-30mm / s; And / or, the annealing treatment temperature is 60-150° C., and the time is 5-20 min.

4. The preparation method according to any one of claims 1 to 3, characterized in that After providing the crystalline silicon cell and before covering the surface of the crystalline silicon cell with the perovskite solution, the method further includes: covering the surface of the crystalline silicon cell with a first functional layer, wherein the first functional layer includes a hole transport layer or an electron transport layer.

5. The preparation method according to any one of claims 1 to 3, characterized in that: The surface roughness of the crystalline silicon cell is not less than 200 nm.

6. The preparation method according to any one of claims 1 to 3, characterized in that: The crystalline silicon cell includes one of a heterojunction solar cell, a tunnel passivation contact cell, and a back contact solar cell.

7. The preparation method according to any one of claims 1 to 3, characterized in that: The coating method includes spin coating, blade coating, evaporation, printing, spray coating, spray drying or slit coating.

8. A crystalline silicon / perovskite tandem cell, characterized in that: include: A crystalline silicon cell, the crystalline silicon cell is used as a bottom cell of the crystalline silicon / perovskite stacked cell, and the surface of the crystalline silicon cell is a rough surface; A perovskite layer, the perovskite layer is located on the surface of the crystalline silicon cell, the perovskite layer is obtained by covering the surface of the crystalline silicon cell with a perovskite solution, the perovskite solution comprising a perovskite material and nanoparticles; The nanoparticles include at least one of silicon dioxide, aluminum oxide, magnesium oxide, and silicon aluminum oxide; In the perovskite solution, the concentration of the nanoparticles is 1×10 -7 -1mg / mL; The particle size of the nanoparticles is 20-300 nm.

9. The crystalline silicon / perovskite tandem cell according to claim 8, characterized in that: A first functional layer is further provided between the crystalline silicon cell and the perovskite layer, and the first functional layer includes an electron transport layer or a hole transport layer.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises a crystalline silicon / perovskite tandem cell prepared by the method according to any one of claims 1 to 7 or comprises a crystalline silicon / perovskite tandem cell according to claim 8 or 9.

Images