Passivation solution, composite layer, solar cell and photovoltaic module

Abstract

The embodiment of the invention provides a passivation solution, a composite layer, a solar cell and a photovoltaic module. The passivation solution comprises an interface passivation material, a first solvent, a second solvent and a third solvent; the polarity of the first solvent is higher than that of the second solvent, and the polarity of the second solvent is higher than that of the third solvent. According to the passivation solution, a mixed system containing high, medium and low polar solvents is adopted, good dissolution of an interface passivation material is achieved, meanwhile, the corrosivity of the whole system to the perovskite surface is reduced through the low polar solvent, interface reaction is promoted by means of the high polar solvent, and therefore on the premise that the integrity of the three-dimensional structure of the perovskite thin film is protected, the performance of the perovskite thin film is improved. The uniformity and compactness of the passivation layer are effectively improved, and the photoelectric conversion efficiency and long-term stability of the perovskite cell are significantly enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, and relates to a passivation solution, a composite layer, a solar cell and a photovoltaic module. BACKGROUND

[0002] With the improvement of energy structure in China, more and more new energy replaces traditional thermal power generation, and solar energy is a renewable new energy. The installation form of solar power generation is simple, the requirement for site is small, and the solar power generation is suitable for use requirements in various occasions, and therefore is widely applied in various fields.

[0003] Perovskite solar cells have attracted much attention due to their excellent photoelectric conversion efficiency, low cost and solution processability. In the structure of perovskite solar cells, the interface quality is one of the key factors affecting the performance and stability of the device. Especially between the perovskite layer and the electron transport layer (or hole transport layer), the interface defects (such as uncoordinated ions, dangling bonds, etc.) will cause non-radiative recombination, reduce the open-circuit voltage and fill factor, and thus affect the cell efficiency.

[0004] In order to improve the interface quality, an interface passivation technology is usually used, that is, a layer of passivation material is coated on the surface of the perovskite to fill the surface defects, inhibit ion migration and improve the energy level matching. The commonly used interface passivation materials at present are mostly organic ammonium salt compounds, such as 2-phenylethylamine hydroiodide (PEAI), benzylamine hydroiodide (PMAI) and the like. These materials are usually dissolved in isopropyl alcohol, but when isopropyl alcohol stays on the surface of the perovskite film for a long time, it is easy to erode the perovskite structure, cause lead iodide (PbI2) to precipitate, destroy the three-dimensional morphology of the perovskite surface, and thus affect the passivation effect and device performance.

[0005] In view of the problems in the prior art, it is necessary to develop a new type of perovskite solar cell.

[0006] It should be noted that the above content is not necessarily prior art, and is not used to limit the patent protection scope of the present application. SUMMARY

[0007] The embodiments of the present application provide a passivation solution, a composite layer, a solar cell and a photovoltaic module to solve or alleviate one or more technical problems proposed above.

[0008] The first aspect of the embodiments of the present application provides a passivation solution, which comprises an interface passivation material and a solvent. The solvent comprises a first solvent, a second solvent and a third solvent. The polarity of the first solvent is higher than that of the second solvent, and the polarity of the second solvent is higher than that of the third solvent.

[0009] Optionally, the interfacial passivation material comprises an organic ammonium salt and / or a derivative of the organic ammonium salt.

[0010] Optionally, the organic ammonium salt comprises any one or a combination of 2-phenylethylamine hydroiodide, 2-(4-fluorophenyl)ethylamine hydroiodide, benzylamine hydroiodide, 4-fluorobenzylamine hydroiodide, 1,3-diaminopropane dihydroiodide, or ethylenediamine dihydroiodide.

[0011] Optionally, the polarity of the first solvent is 20-50, excluding 20.

[0012] Optionally, the polarity of the second solvent is 10-20, excluding 10.

[0013] Optionally, the polarity of the third solvent is 0-10.

[0014] Optionally, the first solvent comprises any one or a combination of 1-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, or sulfolane.

[0015] Optionally, the second solvent comprises any one or a combination of isopropyl alcohol, n-butyl alcohol, or 1-methoxy-2-propanol.

[0016] Optionally, the third solvent comprises any one or a combination of cyclohexane, dimethyl carbonate, ethyl acetate, or n-pentanol.

[0017] Optionally, in the passivation solution, the concentration of the interfacial passivation material is 0-5 mg / mL, excluding 0 mg / mL.

[0018] Optionally, the added volume of the first solvent is 0.1-1% of the total volume of the solvent, the added volume of the second solvent is 19-50% of the total volume of the solvent, and the added volume of the third solvent is 49-80% of the total volume of the solvent.

[0019] In a second aspect, the embodiments of the present application provide a composite layer as described in the first aspect, the composite layer comprising a perovskite absorption layer and a passivation layer located on one side surface of the perovskite absorption layer. The passivation layer is formed by the passivation solution described above.

[0020] Optionally, the thickness of the passivation layer is 1-20 nm.

[0021] Optionally, the formation of the passivation layer comprises coating the passivation solution on one side surface of the perovskite absorption layer, annealing, and forming the passivation layer.

[0022] Optionally, the coating method comprises any one of spin coating, slot coating, blade coating, or spraying.

[0023] Optionally, the annealing temperature is 50-100℃, and the annealing time is 1-10 min.

[0024] In a third aspect, the embodiments of the present application provide a solar cell, which comprises the composite layer of the second aspect.

[0025] In a fourth aspect, the embodiments of the present application provide a photovoltaic module, which comprises the solar cell of the third aspect.

[0026] The embodiments of the present application can have the following advantages: In the present application, by using a mixed system containing high, medium and low polarity solvents, the passivation solution can achieve good dissolution of the interfacial passivation material, reduce the erosion of the overall system to the perovskite surface by using low polarity solvents, and promote the interfacial reaction by using high polarity solvents, thereby effectively improving the uniformity and density of the passivation layer under the premise of protecting the three-dimensional structure integrity of the perovskite thin film, and significantly enhancing the photoelectric conversion efficiency and long-term stability of the perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0027] In the drawings, like reference numerals refer to like elements throughout the various drawings. The drawings are not necessarily to scale, emphasis instead being placed on illustrating principles of the application. It should be understood that the drawings are merely depictions of some embodiments of the application and should not be construed as limiting the scope of the application.

[0028] Figure 1 is a structural schematic diagram of a perovskite single-junction solar cell in the specific embodiment of the present application; Figure 2 is a structural schematic diagram of a stacked solar cell in the specific embodiment of the present application; BRIEF DESCRIPTION OF DRAWINGS 0, bottom cell; 1, base layer; 2, hole transport layer; 3, perovskite absorption layer; 4, passivation layer; 5, electron transport layer; 6, electrode layer; 7, transparent conductive layer. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. In the drawings, the size and relative sizes of layers, regions, elements, and the like can be exaggerated for clarity. Identical or similar components are denoted by identical or similar reference numerals throughout the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. It will also be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. Similarly, a second element, component, region, layer or section discussed below could be termed a first element, component, region, layer or section without departing from the teachings of the present application.

[0031] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

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

[0033] In this application, when referring to a numerical interval (i.e., a numerical range), the distribution of the selectable values in the numerical interval is considered continuous and includes both numerical endpoints (i.e., the minimum and maximum values) of the numerical interval and every value between the two numerical endpoints, unless otherwise specified. When a numerical interval refers only to integers within the numerical interval, including both endpoints and every integer between the endpoints, it is equivalent to listing each integer directly, unless otherwise specified. When multiple numerical ranges are provided to describe a feature or characteristic, the numerical ranges can be combined. In other words, unless otherwise indicated, numerical ranges disclosed in this application are to be understood to include any and all sub-ranges subsumed therein. A "numerical interval" in a numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. A "numerical interval" is intended to broadly include quantitative intervals such as percentage intervals, ratio intervals, and value intervals.

[0034] The embodiments of the present application provide a solar cell and a preparation method and application thereof. Details are shown in the following.

[0035] In the following, 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 carried out in various different ways, and should not be interpreted as being limited only to the embodiments set forth herein.

[0036] The embodiments of the present application provide a passivation solution, which comprises an interfacial passivation material and a solvent; The solvent comprises a first solvent, a second solvent, and a third solvent; The polarity of the first solvent is higher than that of the second solvent, and the polarity of the second solvent is higher than that of the third solvent.

[0037] In the present application, by using a mixed system containing high, medium, and low polarity solvents, the passivation solution can achieve good dissolution of the passivation material, reduce the overall system's erosion of the perovskite surface by using low polarity solvents, and promote interfacial reactions by using high polarity solvents, thereby effectively improving the uniformity and density of the passivation layer under the premise of protecting the three-dimensional structural integrity of the perovskite thin film, and significantly enhancing the photoelectric conversion efficiency and long-term stability of the perovskite solar cell.

[0038] In the present application, by designing a polarity gradient, the passivation solution exhibits excellent spreading and permeability when forming the passivation layer, which helps to form a passivation layer with uniform thickness, high density, and continuity, and effectively passivates surface and grain boundary defects.

[0039] It is noted that the polarity of a solvent is a chemical concept that describes the degree of unevenness of the internal charge distribution of a solvent molecule and its ability to interact with solutes. Due to the non-coincidence of positive and negative charge centers in the solvent molecule, a dipole moment is generated, which determines the behavior of the solvent in the process of dissolution, reaction and transfer. The size of the polarity is usually quantified by physical quantities such as dielectric constant or dipole moment: in general, the larger the dielectric constant, the stronger the polarity of the solvent.

[0040] In some embodiments, the interface passivation material comprises an organic ammonium salt and / or a derivative of an organic ammonium salt; The organic ammonium salt comprises any one or a combination of at least two of 2-phenylethylamine hydroiodide, 2-(4-fluorophenyl)ethylamine hydroiodide, benzylamine hydroiodide, 4-fluorobenzylamine hydroiodide, 1,3-diaminopropane dihydroiodide or ethylenediamine dihydroiodide.

[0041] In this application, a specific type of organic ammonium salt passivation material is selected, and the ammonium group in the molecular structure of the passivation material can form coordinate bonds and ionic bonds with the surface of the perovskite absorption layer, thereby enhancing the interface bonding force.

[0042] In some embodiments, the polarity of the first solvent is 20-50 (for example, the polarity of the first solvent is 25, 30, 35, 40, 45, 50, etc.), excluding 20; The polarity of the second solvent is 10-20 (for example, the polarity of the second solvent is 12, 15, 18, 20, etc.), excluding 10; The polarity of the third solvent is 0-10 (for example, the polarity of the third solvent is 1, 3, 5, 8, 10, etc.).

[0043] In this application, the first solvent has strong solvation ability, which can promote the adsorption and reaction of the passivation molecules on the surface of the perovskite absorption layer, enhance the interaction between the passivation material and the perovskite, promote the formation of two-dimensional / three-dimensional heterojunction, and improve the interface energy level matching and charge extraction efficiency; the second solvent can effectively dissolve the interface passivation material to ensure its uniform dispersion; the third solvent can significantly reduce the overall polarity of the system, reduce the erosion of the solvent on the surface of the perovskite, avoid the precipitation of lead iodide and the destruction of the three-dimensional structure, thereby protecting the integrity of the perovskite film.

[0044] In some embodiments, the first solvent comprises any one or a combination of at least two of 1-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide or sulfolane; The second solvent comprises any one or a combination of at least two of isopropyl alcohol, n-butanol or 1-methoxy-2-propanol; The third solvent comprises any one or a combination of at least two of cyclohexane, dimethyl carbonate, ethyl acetate or n-pentanol.

[0045] In the present application, the first solvent contains strong polar functional groups, which can form dipole-dipole interaction with the surface of the perovskite absorption layer; the second solvent has moderate hydrogen bonding ability, which is beneficial to the dissolution of the passivation material; and the third solvent can adjust the solution viscosity and surface tension, and improve the film uniformity.

[0046] In the present application, the polarity of the specific substances in the first solvent, the second solvent and the third solvent is shown in Table 1: Table 1 Solvent polarity

[0047] It should be noted that the polarity of the solvent in Table 1 is derived from NIST Chemistry WebBook.

[0048] In some embodiments, the concentration of the interfacial passivation material in the passivation solution is 0-5 mg / mL (for example, the concentration is 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL, 4.5 mg / mL, 5 mg / mL, etc.), excluding 0 mg / mL.

[0049] In some embodiments, the volume of the first solvent added is 0.1-1% of the total volume of the solvent (for example, 0.1%, 0.3%, 0.5%, 0.7%, 1%, etc.), the volume ratio of the second solvent to the solvent is 19-50% (for example, 19%, 20%, 30%, 40%, 50%, etc.), and the volume ratio of the third solvent to the solvent is 49-80% (for example, 49%, 50%, 60%, 70%, 80%, etc.).

[0050] In the present application, by controlling the concentration of the interfacial passivation material, the coverage of the passivation layer can be ensured while avoiding excessive thickness that hinders charge extraction; and the first solvent, the second solvent and the third solvent are used in combination to make the solution have good spreading and reactivity on the surface of the perovskite absorption layer.

[0051] The present application provides a composite layer, which comprises a perovskite absorption layer and a passivation layer located on one side of the surface of the perovskite absorption layer. The passivation layer is formed by the passivation solution described above.

[0052] In the present application, the passivation layer can fill the dangling bonds and vacancies on the surface of the perovskite absorption layer, suppress interfacial recombination, and at the same time, the energy level position can adjust the interfacial band alignment to promote charge extraction, thereby significantly reducing the defect density on the surface of the perovskite absorption layer.

[0053] In some embodiments, the passivation layer has a thickness of 1-20 nm (for example, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, etc.).

[0054] In the present application, the thickness of the passivation layer is controlled to be 1-20 nm, which can form a continuous passivation layer, effectively balancing the defect passivation effect and the carrier transport efficiency; when the thickness of the passivation layer is less than 1 nm, there will be a problem that the passivation layer does not cover the surface of the perovskite absorption layer completely; when the thickness of the passivation layer is greater than 20 nm, it may hinder the carrier tunneling.

[0055] In the present application, the material of the perovskite absorption layer is a perovskite structure material with the general formula of ABX3.

[0056] Among them: the A-site cation is usually a monovalent cation, including at least one of a monovalent metal cation and a monovalent organic cation; The monovalent metal cation is selected from any one or a combination of at least two of cesium ions (Cs + ), rubidium ions (Rb + ), lithium ions (Li + ), sodium ions (Na + ), and potassium ions (K + ); The monovalent organic cation is selected from any one or a combination of at least two of ammonium ions (NH4 + ), methylamine ions (MA) (CH3NH3 + ), ethylamine ions (CH3CH2NH3 + ), dimethylamine ions ((CH3)2NH2 + ), trimethylammonium ions ((CH3)3NH + ), tetramethylammonium ions ((CH3)4N + ), formamidinium ions (FA) (HC(NH2)2 + ), methylformamidinium ions (CH3C(NH2)2 + ), ethylformamidinium ions (H3C2(NH2)2 + ), and guanidinium ions (C(NH2)3 + ).

[0057] The B-site cation is usually a divalent metal cation, selected from any one or a combination of at least two of lead ions (Pb 2+ ) or tin ions (Sn 2+ ).

[0058] The X-site anion is a halide anion, including bromide ions (Br - ) and iodide ions (I -any one of or a combination of fluoride ion (F - ), chloride ion (Cl - ), thiocyanate ion (SCN x ).

[0059] As a preferred technical solution of the present application, the perovskite structure material is selected from any one of or a combination of FAPbI3, MAPbI3, CsPbI3 or Cs 1-x FA y Pb(Br 1-y )3, wherein 0.1 < x < 0.3 and 0.15 < y < 0.4.

[0060] In some embodiments, the perovskite structure material comprises a first precursor compound and a second precursor compound. The first precursor compound has a chemical formula of AX and comprises any one of or a combination of FAI (formamidinium iodide), FABr (formamidinium bromide), MAI (methylammonium iodide), MABr (methylammonium bromide), CsI (cesium iodide), and CsBr (cesium bromide); the second precursor compound has a chemical formula of BX2 and comprises any one of or a combination of PbI2 (lead iodide), PbBr2 (lead bromide), SnI2 (tin iodide), and SnBr2 (tin bromide).

[0061] It can be understood that the molar ratio of the first precursor compound to the second precursor compound is usually 1:1, so as to control the molar ratio of A ion, B ion and X ion to be 1:1:3, so that after annealing, the perovskite structure material with a general formula of ABX3 can be obtained to form the perovskite absorption layer.

[0062] In some embodiments, the preparation process of the perovskite absorption layer comprises: first forming a perovskite precursor layer, and then performing annealing crystallization.

[0063] In some embodiments, the method for forming the perovskite precursor layer comprises a coating method.

[0064] The coating method comprises a slot coating method, a doctor blade coating method or a spin coating method.

[0065] In the coating method, the perovskite structure material is mixed with a solvent to form a precursor solution, and the coating is performed by using the precursor solution.

[0066] In the precursor solution, the molar concentration of the perovskite structure material is 1-2 mol / L (for example, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, etc.).

[0067] The solvent in the precursor solution includes any one of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), or dimethyl sulfoxide (DMSO) or a combination of at least two of them, preferably the solvent is a combination of DMF and NMP, a combination of DMF and DMI, or a combination of DMF and DMSO.

[0068] When the solvent is a combination of DMF and NMP, the volume ratio of DMF to NMP is 4:1; When the solvent is a combination of DMF and DMI, the volume ratio of DMF to DMI is 9:1; When the solvent is a combination of DMF and DMSO, the volume ratio of DMF to DMSO is 4:1.

[0069] In some embodiments, the temperature for annealing and crystallization is 90-150°C (for example, the temperature is 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.), and the time is 5-30 min (for example, the time is 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.).

[0070] In some embodiments, the formation of the passivation layer includes: applying a passivation solution to one side surface of the perovskite absorption layer, annealing, and forming a passivation layer.

[0071] In some embodiments, the application method includes any one of spin coating, slot coating, blade coating, or spraying.

[0072] In some embodiments, the annealing temperature is 50-100°C (for example, the annealing temperature is 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc.), and the annealing time is 1-10 min (for example, the annealing time is 1 min, 3 min, 5 min, 8 min, 10 min, etc.).

[0073] In the present application, the preparation method of the passivation layer uses a conventional application method, the process is simple and easy to implement, and annealing can be achieved at a relatively low temperature, thereby avoiding damage to the structure of the perovskite absorption layer.

[0074] In some embodiments, the present application provides a solar cell including the composite layer.

[0075] It should be noted that the solar cell of the present application includes a perovskite single-junction cell or a stacked cell.

[0076] In some embodiments, the present application provides a perovskite single-junction cell, such as Figure 1As shown, it includes a substrate layer 1, a hole transport layer 2, a perovskite absorption layer 3, a passivation layer 4, an electron transport layer 5, and an electrode layer 6, which are stacked together.

[0077] In some embodiments, the material of the hole transport layer includes at least one of transition metal oxides, polymer materials, and small organic molecule materials.

[0078] In some embodiments, the transition metal oxide includes at least one of nickel oxide, molybdenum trioxide, tungsten trioxide, and copper oxide. The preparation processes for the transition metal oxide include solution chromatography, physical vapor deposition (PVD), atomic layer deposition (ALD), and inkjet printing. The thickness of the transition metal oxide is 10-100 nm, preferably 20-50 nm. Organic small molecule materials are often referred to as SAM (self-assembled monolayer) materials. SAM molecules can form a monolayer on the substrate surface through self-assembly, thereby playing a role in regulating interface properties, promoting charge transport, and reducing non-radiative recombination.

[0079] SAM materials typically possess a specific molecular structure. SAM molecules generally consist of anchoring groups, linking groups, and terminal groups. Anchoring groups usually contain polar atoms (such as oxygen, nitrogen, and sulfur) or active functional groups, capable of forming chemical bonds (such as covalent bonds, coordinate bonds, or strong hydrogen bonds) with hydroxyl groups (-OH) or metal atoms on the TCO surface. Common types of anchoring groups include carboxyl groups (-COOH), phosphonic acid groups (-PO(OH)2), hydroxyl groups (-OH), and thiol groups (-SH). The bonding strength of the anchoring groups directly determines the stability of the SAM (such as water resistance and heat resistance); if the bonding is too weak, the SAM is prone to detachment, leading to device performance degradation.

[0080] Terminal groups typically contact the perovskite layer, and their main function is to regulate the interfacial energy level matching, wettability, and charge extraction efficiency between SAM and the perovskite layer. Common types of terminal groups are amino (-NH2), cyano (-CN), alkyl (-CH3), and conjugated groups. Among these, common types of conjugated structures are benzene rings and thiophenes.

[0081] The linking group is the "backbone" in a SAM molecule that connects the anchoring group and the terminal group. It is usually composed of a carbon chain, typically C6-C6. 18 The alkyl chain. The length of the linking group determines the spatial distance between the anchoring group (TCO side) and the terminal group (perovskite side). The length and chemical properties of the linking group also affect the order, conductivity, and steric hindrance of the SAM.

[0082] Common SAM materials include: [2] (9H carbazole 9 carbazole (3,6 diphenyl 9H carbazole 9 carbazole (3,6 dimethyl 9H carbazole 9 carbazole (3,6 dimethoxy 9H carbazole 9 carbazole (7H dibenzocarbazole 7 carbazole (2,7 dibromo 9,9 dimethylacridine 10(9 hydrogen) [2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanoethenyl]phosphonic acid (MPA-CPA), [2-(3,7-dibromo-10H-phenothiazin-10-yl)ethyl]phosphonic acid (Br-2EPT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), and the like.

[0083] In some alternative embodiments, when the hole transport layer is made of SAM material, the hole transport layer is prepared by the following process: The SAM material is mixed with a solvent, stirred at room temperature in a nitrogen atmosphere glove box until completely dissolved to obtain a hole transport layer solution, and the concentration of the SAM material in the hole transport layer solution is 0.1-3 mg / mL. The hole transport layer solution is coated in a nitrogen atmosphere glove box to obtain a wet film, and then heated and annealed on a hot stage at 80-120°C for 5-20 min to form a hole transport layer.

[0084] In some alternative embodiments, the hole transport layer is prepared by an inkjet printing process. The process parameters of the inkjet printing are as follows: nozzle diameter: in the range of 10-50 μm, determining the droplet volume of 1-100 pL; driving voltage: usually 20-100 V, used to control the droplet speed and morphological stability; substrate temperature: generally controlled at 40-80°C, used to regulate the solvent evaporation rate and crystallization quality; printing resolution: up to 300-1200 dpi, affecting the pattern accuracy and film uniformity; annealing: hot plate 100°C heating treatment of the film. The raw material is processed on the substrate to form a hole transport layer with a thickness in the range of 10-100 nm.

[0085] In some embodiments, the material of the electron transport layer includes any one of inorganic metal oxide material, organic material, inorganic silicon material, or inorganic salt material.

[0086] The inorganic metal oxide material includes any one of SnO2, TiO2, ZnO, ZrO2, ZnO, MgO, gallium zinc oxide, indium zinc oxide, fluorine-doped tin oxide, or indium tin oxide, or a combination of at least two of them.

[0087] The preparation processes of inorganic metal oxide materials include sol-gel method, atomic layer deposition (ALD), chemical vapor deposition (CVD, including plasma enhanced chemical vapor deposition (PECVD), metal organic chemical vapor deposition (MOCVD), etc.), physical vapor deposition (PVD, including magnetron sputtering, thermal evaporation, pulsed laser deposition (PLD), etc.), spray pyrolysis, solution spin coating, electrochemical deposition, and chemical bath deposition, etc. Preferably, atomic layer deposition (ALD) is used.

[0088] The specific process of atomic layer deposition (ALD) for preparing the electron transport layer of inorganic metal oxide material includes: alternately introducing metal precursor and oxygen source under the condition of 0.05-1.5 Torr (for example, 0.05 Torr, 0.1 Torr, 0.5 Torr, 1.0 Torr, 1.5 Torr) of air pressure. The flow rate of metal precursor in each cycle is 10-100 sccm (for example, 10 sccm, 30 sccm, 50 sccm, 80 sccm, 100 sccm), and the pulse time of metal precursor in each cycle is 100-300 ms (for example, 100 ms, 150 ms, 200 ms, 250 ms, 300 ms). The flow rate of oxygen source in each cycle is 10-100 sccm (for example, 10 sccm, 30 sccm, 50 sccm, 80 sccm, 100 sccm), and the pulse time of oxygen source in each cycle is 100-300 ms (for example, 100 ms, 150 ms, 200 ms, 250 ms, 300 ms).

[0089] The thickness of the electron transport layer of inorganic metal oxide material prepared by atomic layer deposition (ALD) is 20-200 nm (for example, 20 nm, 50 nm, 80 nm, 100 nm, 150 nm, 200 nm), and the growth rate of inorganic metal oxide is usually between 0.03-0.2 nm / cycle (for example, 0.03 nm / cycle, 0.05 nm / cycle, 0.1 nm / cycle, 0.15 nm / cycle, 0.2 nm / cycle), and the required number of cycles depends on the type of metal precursor, the type of oxygen source and the process temperature. It should be noted that the first time of introducing metal precursor and oxygen source is metal precursor.

[0090] The organic material includes any one of C60, fullerene C70, (6,6)-phenyl-C61-butyric acid methyl ester (PCBM), or 4-(1',5'-dihydro-1'-methyl-2'H-(5,6) fullerene-C60-In-(1,9-c) pyrrole-2'-yl) benzylamine chloride (CPMAC), or a combination of at least two of them.

[0091] The organic material preparation process includes vacuum evaporation, spin coating, inkjet printing, blade coating, slot coating, dip coating, spray coating, drop coating, and roll-to-roll printing. Preferably, the vacuum evaporation method, the vacuum evaporation rate is 0.05-0.1 nm / s (exemplary, the evaporation rate is 0.05 nm / s, 0.06 nm / s, 0.07 nm / s, 0.08 nm / s, 0.09 nm / s, 0.1 nm / s).

[0092] The inorganic silicon material includes any one of n-type single crystal silicon, n-type polycrystalline silicon, or n-type amorphous silicon, or a combination of at least two of them.

[0093] The inorganic silicon material preparation process mainly includes low pressure chemical vapor deposition (LPCVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), magnetron sputtering, thermal diffusion (such as phosphorus diffusion), ion implantation, sol-gel method, and electron beam evaporation, etc.

[0094] The inorganic salt material includes any one of BaSnO3, TiSnO x or SnZnO x , or a combination of at least two of them.

[0095] The inorganic salt material preparation process mainly includes sol-gel method, atomic layer deposition (ALD), chemical vapor deposition (CVD, including plasma enhanced chemical vapor deposition PECVD), physical vapor deposition (PVD, including magnetron sputtering, pulsed laser deposition PLD, electron beam evaporation), spray pyrolysis, solution spin coating, electrochemical deposition, chemical bath deposition, and magnetron sputtering-annealing combined method, etc.

[0096] As a preferred technical solution of the present application, the material of the electron transport layer includes C60, fullerene derivative (6,6) phenyl C61 butyric acid methyl ester (PCBM), a combination of C60 and PCBM, a combination of PCBM and ZnO, a combination of ZnO and MgO, a combination of C60, PCBM, and ZnO, a combination of PCBM, ZnO, and MgO, and a combination of C60, PCBM, ZnO, and MgO.

[0097] In some embodiments, the thickness of the electron transport layer is 3-50 nm (exemplarily, 3 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.).

[0098] In some embodiments, the method for preparing the electron transport layer includes wet coating, sol-gel method, chemical vapor deposition, physical vapor deposition or plasma deposition.

[0099] In some embodiments, the material of the electrode layer includes any one or a combination of at least two of copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), cobalt (Co), gold (Au), molybdenum (Mo) or chromium (Cr), preferably a combination of Ag, copper, Cu and Al, a combination of Ag and Ni, a combination of Co and Au, a combination of Mo and Cr, or a combination of Cu, Al, Ag, Ni, Co, Au, Mo and Cr.

[0100] In some embodiments, the method for preparing the electrode layer includes but is not limited to evaporation, screen printing, electroplating, laser technology, PVD (Physical Vapor Deposition), inkjet printing, and the thickness of the electrode is 0.1-20 μm.

[0101] In some embodiments, the present application provides a stacked battery, as shown in FIG. 1, which includes a bottom cell 0, a hole transport layer 2, a perovskite absorption layer 3, a passivation layer 4, an electron transport layer 5, a transparent conductive layer 7 and an electrode layer 6 arranged in layers. Figure 2

[0102] In some embodiments, the bottom cell can be a crystalline silicon bottom cell, a CIGS thin film bottom cell, a cadmium telluride thin film bottom cell, a III V thin film bottom cell or a perovskite bottom cell.

[0103] In some embodiments, the crystalline silicon bottom cell includes an N-type monocrystalline silicon substrate, a P-type amorphous silicon thin film (P face) and a silver electrode deposited on the front side of the N-type monocrystalline silicon substrate, an N-type amorphous silicon thin film (N face) and a transparent conductive oxide layer deposited on the back side of the N-type monocrystalline silicon substrate.

[0104] In some embodiments, the thickness of the N-type monocrystalline silicon substrate is 90-220 μm, which is mainly used for absorbing light and generating carriers; the thickness of the P-type amorphous silicon is 5-30 nm, which is mainly used as an emitter to form a P-N heterojunction; the thickness of the silver electrode is 2-30 μm, which is mainly used for collecting current and leading out; the thickness of the N-type amorphous silicon thin film is 5-30 nm, which is mainly used for forming a back surface field to promote electron collection; the thickness of the transparent conductive oxide layer is 70-100 nm, which is mainly used for lateral conduction and anti-reflection.

[0105] ​In some embodiments, the substrate can also be polyimide (PI), polyester (PET), polyethylene naphthalate (PEN), or a metal foil, thus making a flexible solar cell.

[0106] Embodiment 1 The embodiment provides a passivation solution, which comprises an interfacial passivation material, a first solvent, a second solvent, and a third solvent; the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the concentration of the interfacial passivation material in the passivation solution is 1 mg / mL; the first solvent is 1-methyl-2-pyrrolidone (NMP), and the volume ratio of the first solvent in the passivation solution is 0.5%; the second solvent is isopropyl alcohol, and the volume ratio of the second solvent in the passivation solution is 35%; and the third solvent is cyclohexane, and the volume ratio of the third solvent in the passivation solution is 64.5%.

[0107] The embodiment provides a composite layer, which comprises a perovskite absorption layer and a passivation layer located on one side surface of the perovskite absorption layer, and a preparation method comprises the following steps: The passivation solution is coated on the surface of the perovskite absorption layer, and the perovskite absorption layer is annealed at 65 ℃ for 5 min to form the passivation layer.

[0108] The embodiment provides a perovskite single-junction cell, which comprises a substrate layer, a hole transport layer, a composite layer, an electron transport layer, and an electrode layer arranged in a stack from bottom to top, wherein the composite layer is the composite layer formed in the above method and comprises a perovskite absorption layer and a passivation layer.

[0109] The embodiment provides a preparation method of a perovskite single-junction cell, which comprises the following steps: S101, cleaning an ITO transparent conductive substrate: 1×1 cm 2 ITO transparent conductive substrate is sequentially immersed in ethanol, detergent, ultrapure water, isopropyl alcohol, and ethanol for ultrasonic cleaning, and the cleaned ITO transparent conductive substrate is dried with nitrogen; the volume of the solvent used for ultrasonic cleaning is 500 mL, and the time for each ultrasonic cleaning is 15 minutes. The ITO transparent conductive substrate comprises a substrate substrate and an ITO transparent conductive layer deposited on the substrate substrate; the material of the substrate substrate is soda-lime glass, and the thickness of the substrate substrate is 2 mm; the ITO transparent conductive layer is composed of 90% of indium oxide (In2O3) and 10% of tin oxide (SnO2) by mass percentage, and the thickness of the ITO transparent conductive layer is 80 nm.

[0110] S102, preparing a hole transport layer: mixing SAM material 2PACz with anhydrous ethanol and stirring until the 2PACz is completely dissolved to obtain a SAM solution; the concentration of the 2PACz in the SAM solution is 1 mg / mL; In a glove box under nitrogen atmosphere, the SAM solution was spin-coated on the ITO transparent conductive layer of the ITO transparent conductive substrate at a spin-coating speed of 3000 rpm for 30 s, and then was heated on a hot stage at 100 ℃ for 10 min to form a SAM layer, which constituted a hole transport layer.

[0111] S103, preparing a perovskite absorption layer: a perovskite precursor solution was prepared by mixing PbI2, PbBr2, CsI, FAI and MABr in stoichiometric ratios, and was ready for use after complete dissolution; the perovskite precursor solution was coated on the hole transport layer by a coating process to prepare a perovskite wet film, the coating speed was 10 mm / s, and the coating gap Gap was 200 μm; the ITO transparent conductive substrate with the perovskite wet film was placed in a VCD device for vacuum drying, and was quickly vacuumed to below 10 Pa and kept for 2 min to obtain a perovskite dry film; the perovskite dry film was annealed at 100 ℃ for 30 min on a hot stage to obtain a perovskite layer with a chemical formula of Cs 0.1 FA 0.8 MA 0.1 PbI 2.1 Br 0.9 .

[0112] S104, preparing a passivation layer: a passivation material 2-phenylethylamine hydroiodide (PEAI) was mixed with a first solvent, a second solvent and a third solvent to obtain an interface passivation solution, the concentration of 2-phenylethylamine hydroiodide (PEAI) was 1 mg / mL, wherein the first solvent was 1-methyl-2-pyrrolidone (NMP), the second solvent was isopropyl alcohol, and the third solvent was cyclohexane, the volume percentage of the first solvent was 0.5%, the volume percentage of the second solvent was 35%, and the volume percentage of the third solvent was 64.5%; the passivation solution was coated on the surface of the perovskite layer and was annealed at 65 ℃ for 5 min to obtain a passivation layer.

[0113] S105, preparing an electron transport layer: the ITO transparent conductive substrate with the passivation layer was transferred to a vacuum coating instrument, and a layer of 10 nm thick C60 was evaporated on the passivation layer; then a layer of 5 nm thick tin dioxide (SnO2) was prepared on the C60 by atomic layer deposition, and the C60 and SnO2 constituted an electron transport layer.

[0114] S106, preparing a metal electrode: the ITO transparent conductive substrate with the electron transport layer was transferred to a vacuum coating instrument, and a 200 nm thick silver electrode was evaporated to obtain a single-junction perovskite solar cell.

[0115]

Example 2

[0116] [Example 3] The difference from Example 1 is that in Example 3, the volume ratio of the first solvent is 0.1%, the volume ratio of the second solvent is 25%, and the volume ratio of the third solvent is 74.9%.

[0117] [Example 4] The difference from Example 1 is that in Example 4, the volume ratio of the first solvent is 1%, the volume ratio of the second solvent is 19%, and the volume ratio of the third solvent is 80%.

[0118] [Example 5] The difference from Example 1 is that in Example 5, the material of the first solvent is replaced by dimethyl sulfoxide (DMSO), the material of the second solvent is replaced by n-butanol, and the material of the third solvent is replaced by ethyl acetate.

[0119] [Example 6] The difference from Example 1 is that in Example 6, the material of the interfacial passivation is replaced by 1,3-diaminopropane dihydroiodide; the material of the first solvent is replaced by dimethylformamide, the material of the second solvent is replaced by 1-methoxy-2-propanol, and the material of the third solvent is replaced by n-pentanol.

[0120] [Comparative Example 1] The difference from Example 1 is that the passivation solution includes an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the solvent is isopropyl alcohol, and the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL.

[0121] [Comparative Example 2] The difference from Example 1 is that there is no passivation layer between the perovskite absorption layer and the electron transport layer.

[0122] [Comparative Example 3] The difference from Example 1 is that the passivation solution includes an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the solvent is a combination of isopropyl alcohol and cyclohexane, and the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL, and the volume ratio of isopropyl alcohol and cyclohexane is the same as that of Example 1.

[0123] [Comparative Example 4] The difference from Example 1 is that the passivation solution comprises an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), the solvent is a combination of isopropyl alcohol and 1-methyl-2-pyrrolidone, the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL, and the volume ratio of isopropyl alcohol and 1-methyl-2-pyrrolidone is the same as that of Example 1.

[0124] The perovskite single-junction cells prepared in Examples 1-6 and Comparative Examples 1-4 are tested for short-circuit current, open-circuit voltage, fill factor, and light conversion efficiency, and the test results are shown in Table 2.

[0125] Table 2 Performance test of perovskite single-junction cells obtained in Examples 1-6 and Comparative Examples 1-4

[0126] It can be known from the comparison of Examples 1-6 that when the passivation solution is used in combination of the interfacial passivation material, the first solvent, the second solvent, and the third solvent, the passivation layer formed thereby is used in the perovskite single-junction cell, and the efficiency of the cell is obviously improved.

[0127] It can be known from the comparison of Example 1 and Comparative Examples 1-4 that when the passivation layer is not included, or the solvent combination in the passivation solution is not used in combination of three solvents with different polarities, the light conversion efficiency of the cell is affected; and when the passivation layer is arranged between the perovskite absorption layer and the electron transport layer, and the passivation layer is prepared using the passivation solution prepared in combination of three solvents with specific polarities, the efficiency of the cell can be obviously improved.

[0128]

Example 7

[0129] The present embodiment provides a composite layer comprising a perovskite absorption layer and a passivation layer arranged on one side surface of the perovskite absorption layer, and a preparation method thereof, which comprises: The passivation solution is coated on the surface of the perovskite absorption layer, and annealed at 65℃ for 5 min to form the passivation layer.

[0130] The present embodiment provides a stacked cell comprising a bottom cell, a hole transport layer, a composite layer, an electron transport layer, a transparent conductive layer, and an electrode layer arranged in a stack from bottom to top, wherein the composite layer is the composite layer formed above, and comprises a perovskite absorption layer and a passivation layer.

[0131] The embodiment provides a preparation method of a stacked battery, comprising the following steps: S701, providing a crystalline silicon bottom cell: the crystalline silicon bottom cell comprises an N-type monocrystalline silicon substrate with a thickness of 100 μm, a P-type amorphous silicon film (P face) with a thickness of 10 nm, an indium tin oxide (ITO) transparent conductive layer with a thickness of 20 nm and a back electrode with a thickness of 5 μm, which are sequentially deposited on the back surface (backlight surface) of the N-type monocrystalline silicon substrate, and an N-type amorphous silicon film (N face) with a thickness of 10 nm, an indium tin oxide (ITO) interconnection layer with a thickness of 20 nm, which are sequentially deposited on the light-facing surface of the N-type monocrystalline silicon substrate.

[0132] In a glue homogenizer, ethanol is spin-coated on the indium tin oxide (ITO) interconnection layer on the N face of the crystalline silicon bottom cell at a rotating speed of 3000 rpm for 30 s, and the operation is repeated twice, and then heat treatment is performed at 200 ℃ for 10 min to complete cleaning.

[0133] S702, preparing a hole transport layer: the crystalline silicon bottom cell is placed in a mask plate for sputtering NiOx, and the mask plate is placed in a magnetron sputtering device, and vacuum pumping is performed to 7×10 -4 Pa, a radio frequency magnetron sputtering mode is selected, the power is adjusted to 200 W, the argon flow rate is set to 30 sccm, and sputtering is performed for 5 min to form a NiOx layer on the indium tin oxide (ITO) interconnection layer; SAM material 2PACz is mixed with anhydrous ethanol to be completely dissolved to obtain a SAM solution, and the concentration of 2PACz in the SAM solution is 1 mg / mL; The SAM solution is spin-coated on the NiOx layer at a spin-coating speed of 3000 rpm and a spin-coating time of 30 s, and then annealed at 100 ℃ for 10 min on a hot table to form a SAM layer, and the SAM layer and the NiOx layer constitute a hole transport layer.

[0134] S703, preparing a perovskite layer: a perovskite precursor solution is prepared by mixing PbI2, PbBr2, CsI, FAI and MABr in a stoichiometric ratio by using a coating combined with vacuum drying (VCD) process, and the solution can be used after complete dissolution, the perovskite precursor solution is coated on the hole transport layer by a coating process to prepare a perovskite wet film, the coating speed is 10 mm / s, the coating gap Gap is 200 μm, the crystalline silicon bottom cell with the perovskite wet film is placed in a VCD device for vacuum drying, rapid vacuum pumping is performed to reach below 10 Pa and pressure maintaining is performed for 2 min to obtain a perovskite dry film, and the perovskite dry film is annealed on a hot table at 100 ℃ for 30 min to obtain a perovskite layer with a chemical general formula of Cs 0.1 FA 0.8 MA 0.1 PbI 2.1 Br 0.9a perovskite layer.

[0135] S704, a passivation layer is prepared: a passivation material phenylamine hydroiodide (PMAI) is mixed with a first solvent, a second solvent and a third solvent to obtain an interface passivation solution, the concentration of 2-phenylethylamine hydroiodide (PEAI) is 1 mg / mL, wherein the first solvent is 1-methyl-2-pyrrolidone (NMP), the second solvent is isopropyl alcohol, and the third solvent is cyclohexane, the volume percentage of the first solvent is 0.5%, the volume percentage of the second solvent is 40%, and the volume percentage of the third solvent is 59.5%, the passivation solution is coated on the surface of the perovskite layer, and the passivation layer is obtained by annealing at 65 DEG C for 5 min.

[0136] S705, an electron transport layer is prepared: a layer of 10 nm thick C60 is evaporated on the passivation layer, and then a layer of 5 nm thick tin dioxide (SnO2) is prepared on the C60 by using an atomic layer deposition process, and the C60 and SnO2 constitute the electron transport layer.

[0137] S706, a transparent conductive layer is prepared: an indium zinc oxide (IZO) transparent conductive layer is deposited on the surface of the electron transport layer by radio frequency magnetron sputtering at room temperature, the sputtering power is controlled to be 300 W, the cavity pressure is 0.6 Pa, the argon flow rate is 20 sccm, the 5% argon-oxygen mixed gas flow rate is 5 sccm, and the sputtering time is 210 s.

[0138] S707, a silver electrode layer is prepared: silver paste is coated on the indium zinc oxide (IZO) transparent conductive layer by using a screen printing process to form a patterned silver paste layer, and a silver electrode layer with a thickness of 200 nm is formed by annealing, thereby obtaining a perovskite / crystalline silicon stacked battery.

[0139]

Example 8

[0140]

Example 9

[0141]

Example 10

[0142]

Example 11

[0143] [Example 12] The difference between Example 7 and Example 12 is that in Example 12, the material of the interfacial passivation is replaced by 1,3-diaminopropanedihydroiodide; the material of the first solvent is replaced by sulfolane, the material of the second solvent is replaced by n-butanol, and the material of the third solvent is replaced by dimethyl carbonate.

[0144] [Comparative Example 5] The difference between Example 7 and Comparative Example 5 is that the passivation solution comprises an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the solvent is isopropanol, and the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL.

[0145] [Comparative Example 6] The difference between Example 7 and Comparative Example 6 is that no passivation layer is provided between the perovskite absorption layer and the electron transport layer.

[0146] [Comparative Example 7] The difference between Example 7 and Comparative Example 7 is that the passivation solution comprises an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the solvent is a combination of isopropanol and cyclohexane, and the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL, and the volume ratio of isopropanol and cyclohexane is the same as that of Example 1.

[0147] [Comparative Example 8] The difference between Example 7 and Comparative Example 8 is that the passivation solution comprises an interfacial passivation material and a solvent, the interfacial passivation material is 2-phenylethylamine hydroiodide (PEAI), and the solvent is a combination of isopropanol and 1-methyl-2-pyrrolidone, and the concentration of 2-phenylethylamine hydroiodide (PEAI) in the solvent is 1 mg / mL, and the volume ratio of isopropanol and 1-methyl-2-pyrrolidone is the same as that of Example 1.

[0148] The short-circuit current, open-circuit voltage, fill factor, and light conversion efficiency of the stacked batteries prepared in Examples 7-12 and Comparative Examples 5-8 were tested, and the test results are shown in Table 3.

[0149] Table 3 Performance test of stacked batteries obtained in Examples 7-12 and Comparative Examples 5-8

[0150] It can be seen from the comparison of Examples 7-12 that when the passivation solution is prepared by using the interfacial passivation material, the first solvent, the second solvent and the third solvent in combination, the passivation layer formed by the passivation solution is used in the stacked battery, and the efficiency of the battery is obviously improved.

[0151] It can be seen from the comparison of Examples 7 and Comparative Examples 5-8 that when the passivation layer is not included, or the solvent combination in the passivation solution is not prepared by using three solvents with different polarities, the light conversion efficiency of the battery is affected; and when the passivation layer is arranged between the perovskite absorption layer and the electron transport layer, and the passivation layer is prepared by using the passivation solution prepared by using three solvents with specific polarities in combination, the efficiency of the battery can be obviously improved.

[0152] The embodiments of the present application can also provide a photovoltaic module (not shown), which comprises the solar cell as described above. The solar cell can be connected in series and / or parallel with one or more other solar cells in a predetermined manner. Among them, a plurality of cells can form a cell string, and adjacent cells can be connected together by string welding.

[0153] The embodiments of the present application can provide a photovoltaic system comprising the photovoltaic module in any of the above embodiments. The photovoltaic system also has the advantages of the photovoltaic module, which will not be described here. The application field of the photovoltaic system is wide, and is not limited to photovoltaic power stations, such as ground power stations, roof power stations and water surface power stations, but also includes various devices and apparatuses that utilize solar power, such as user solar power sources, solar street lamps, solar cars and solar buildings, etc. Of course, it can be understood that the application field of the photovoltaic system is not limited to this, that is, the photovoltaic system can be applied in all fields that need to use solar power to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a combiner box and an inverter, the photovoltaic array can be an array combination of a plurality of photovoltaic modules, for example, a plurality of photovoltaic modules can form a plurality of photovoltaic arrays, the photovoltaic array is connected to the combiner box, the combiner box can combine the current generated by the photovoltaic array, the combined current flows through the inverter to convert into alternating current required by the power grid, and then is connected to the power network to realize solar power supply.

[0154] It should be noted that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like merely are used to facilitate the description of the application and are not intended to limit or restrict the scope of the application to the terms so used. The terms "inner", "outer" refer to the inner and outer with respect to the contour of each component itself. For example, if the device in the drawings is inverted, the device described as "above" or "above" other devices or configurations will be positioned "below" or "below" other devices or configurations. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein are interpreted accordingly.

[0155] It should also be noted that the "one embodiment", "another embodiment", "embodiment", and the like in the present application refer to the specific features, structures or characteristics described in connection with the embodiment, which are included in at least one embodiment described in the general description of the present application. The same expression appearing in several places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in connection with any embodiment, it is claimed that the implementation of such feature, structure or characteristic in connection with other embodiments also falls within the scope of the present application.

[0156] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0157] It should also be noted that the above is only the preferred embodiment of the present application, and does not limit the patent protection scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A passivation solution, characterized in that, The passivation solution includes an interface passivation material and a solvent; The solvent includes a first solvent, a second solvent, and a third solvent; The first solvent has a higher polarity than the second solvent, and the second solvent has a higher polarity than the third solvent.

2. The passivation solution according to claim 1, characterized in that, The interface passivation material includes organic ammonium salts and / or derivatives of organic ammonium salts; The organic ammonium salt includes any one or a combination of at least two of the following: 2-phenylethylamine hydroiodide, 2-(4-fluorophenyl)ethylamine hydroiodide, benzylamine hydroiodide, 4-fluorobenzylamine hydroiodide, 1,3-diaminopropane dihydroiodide, or ethylenediamine dihydroiodide.

3. The passivation solution according to claim 1, characterized in that, The polarity of the first solvent is 20-50, excluding 20; The polarity of the second solvent is 10-20, excluding 10; The polarity of the third solvent is 0-10.

4. The passivation solution according to claim 1, characterized in that, The first solvent includes any one or a combination of at least two of 1,3-dimethyl-2-imidazolinone, diethylformamide, 1-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, or sulfolane. The second solvent includes any one or a combination of at least two of isopropanol, n-butanol, or 1-methoxy-2-propanol; The third solvent includes any one or a combination of at least two of cyclohexane, dimethyl carbonate, ethyl acetate, or n-pentanol.

5. The passivation solution according to claim 1, characterized in that, In the passivation solution, the concentration of the interface passivation material is 0-5 mg / mL, excluding 0 mg / mL; The volume of the first solvent added is 0.1-1% of the total volume of the solvent, the volume of the second solvent added is 19-50% of the total volume of the solvent, and the volume of the third solvent added is 49-80% of the total volume of the solvent.

6. A composite layer, characterized in that, The composite layer includes a perovskite absorber layer and a passivation layer located on one side surface of the perovskite absorber layer. The passivation layer is formed using the passivation solution described in any one of claims 1-5.

7. The composite layer according to claim 6, characterized in that, The thickness of the passivation layer is 1-20 nm.

8. The composite layer according to claim 6, characterized in that, The passivation layer is formed by: coating a passivation solution onto one side surface of the perovskite absorber layer and annealing it to form a passivation layer; The coating method includes any one of spin coating, slot coating, blade coating, or spray coating. The annealing temperature is 50-100℃, and the annealing time is 1-10 min.

9. A solar cell, characterized in that, The solar cell includes the composite layer as described in any one of claims 6-8.

10. A photovoltaic module, characterized in that, The photovoltaic module includes the solar cell as described in claim 9.

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