Perovskite solar cell, preparation method thereof, photovoltaic module and photovoltaic system

Abstract

The embodiment of the invention provides a perovskite solar cell, a preparation method thereof, a photovoltaic module and a photovoltaic system, and relates to the technical field of perovskite solar cells. The perovskite solar cell comprises a self-assembled single layer, the self-assembled single layer is formed by an HTL precursor solution; the HTL precursor solution is prepared from SAM, poly (N-isopropylacrylamide) and an organic solvent. Poly (N-isopropylacrylamide) is added into an HTL precursor solution, in the large-area coating process, uniform distribution of a single-molecule self-assembly material can be promoted, and the effect of optimizing the film forming condition of a self-assembly single layer is achieved; the poly (N-isopropylacrylamide) can also effectively relieve the phenomenon of SAM micelle agglomeration, promote uniform distribution of a monomolecular self-assembly material, assist in passivating free Pb < + > on a perovskite interface, facilitate formation of a large-area and compact perovskite light absorption layer, and improve the photoelectric conversion efficiency. Therefore, the short-circuit current density, the open-circuit voltage and the photoelectric conversion efficiency of the perovskite solar cell are improved.

Description

Technical Field

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

[0002] Perovskite materials originally referred to a mineral composed of inorganic calcium titanate (CaTiO3), and later used to refer to a family of compounds with an ABX3 structure. Perovskite materials can be used to prepare perovskite solar cells (PSCs). Perovskite solar cells have broad application prospects due to their low-temperature solution processability and excellent optoelectronic properties. Self-assembled monolayers (SAMs) have the advantages of easily adjustable perovskite energy level arrangement, less parasitic absorption, sufficient stability and easy processing, which are compatible with low-cost and scalable production. The SAM molecules in self-assembled monolayers (SAMs) usually include an anchor group that can bind to the substrate, a flexible spacer group that provides sufficient rotational freedom for self-assembly, and a functional head group to promote efficient hole extraction. Through reasonable molecular design, ultrathin and efficient hole selection layers (HSLs) can be formed. Self-assembled monolayers (SAMs) as hole selection layers (HSLs) can significantly reduce charge transport losses, thereby improving the short-circuit current density (JSC) and open-circuit voltage (VOC) in perovskite solar cells and achieving high power conversion efficiency.

[0003] Recently, self-assembled monolayers (SAMs) have been used as effective hole-selective layers (HSL) to replace traditional organic hole-transporting layers (HTL). However, when self-assembled monolayers (SAMs) are used as hole-selective layers (HSL), the SAM molecules in the self-assembled monolayers (SAMs) tend to aggregate, which is not conducive to the preparation of large-area perovskite solar cells and will significantly reduce the photoelectric conversion efficiency of perovskite solar cells.

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

[0005] The embodiments of the present application provide a perovskite solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system to solve or alleviate the technical problems raised above. In the embodiments of the present application, poly (N-isopropylacrylamide) is added to the HTL (hole transport layer) precursor solution, which can increase the viscosity of the HTL precursor solution and reduce the fluidity of the HTL precursor solution. In the process of coating the HTL precursor solution over a large area, poly (N-isopropylacrylamide) can also promote the uniform distribution of the single-molecule self-assembled materials in the HTL precursor solution, thereby optimizing the film formation of the self-assembled monolayer; poly (N-isopropylacrylamide) can also effectively alleviate the phenomenon of SAM micelle agglomeration, further promote the uniform distribution of the single-molecule self-assembled materials, and poly (N-isopropylacrylamide) can also assist in passivating the free Pb at the perovskite interface. + , which facilitates the formation of a large-area and dense perovskite light absorption layer, thereby helping to reduce the defects at the interface between the perovskite light absorption layer and the self-assembled monolayer, and is beneficial to the transmission of holes, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of perovskite solar cells.

[0006] To achieve the above purpose, this application adopts the following technical solutions: A perovskite solar cell, comprising: a self-assembled monolayer; the self-assembled monolayer is formed by a HTL precursor solution; the HTL precursor solution comprises SAM, poly (N-isopropylacrylamide), and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

[0007] In some embodiments, in the HTL precursor solution, the concentration of the SAM is 0.2-0.6 mg / ml; And / or, in the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.2-2.5 mg / ml.

[0008] In some embodiments, in the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.4-2.0 mg / ml.

[0009] In some embodiments, the organic solvent includes N,N-dimethylformamide and a polar solvent; the polar solvent is one or more of ethanol and isopropanol.

[0010] In some embodiments, the volume ratio of the polar solvent to the N,N-dimethylformamide in the organic solvent is 1-9:1.

[0011] In some embodiments, a perovskite light absorbing layer is further included, and the perovskite light absorbing layer is disposed on the self-assembled monolayer; The perovskite light absorption layer is formed by a perovskite precursor solution; the perovskite precursor solution comprises: a perovskite material and a solvent; Wherein, the perovskite material includes any one of FAMAPbI, FACsPbI3, and FAMACsPbI3; The solvent includes any one of a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide and a mixed solution of γ-butyrolactone and N-methylpyrrolidone; the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide in the mixed solution of N,N-dimethylformamide and dimethyl sulfoxide is 3-5:1; the volume ratio of γ-butyrolactone to N-methylpyrrolidone in the mixed solution of γ-butyrolactone and N-methylpyrrolidone is 3-5:1.

[0012] In some embodiments, the perovskite precursor solution further comprises poly (N-isopropylacrylamide); the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml.

[0013] In some embodiments, the perovskite solar cell further includes a conductive substrate, a perovskite light absorbing layer, an electron transport layer, a hole blocking layer, and a metal electrode; Wherein, the self-assembled monolayer, the perovskite light absorption layer, the electron transport layer, the hole blocking layer, and the metal electrode are sequentially stacked on the conductive substrate.

[0014] The embodiment of the present application also provides a method for preparing a perovskite solar cell, comprising: sequentially preparing a self-assembled monolayer and a perovskite light absorption layer on a conductive substrate; the self-assembled monolayer is formed by a HTL precursor solution; the HTL precursor solution comprises SAM, poly (N-isopropylacrylamide), and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

[0015] In some embodiments, after preparing the self-assembled monolayer and before preparing the perovskite light absorbing layer, the method further includes performing a first annealing; the annealing temperature of the first annealing is 100-120° C., and the annealing time is 10-15 min; And / or, after preparing the perovskite light absorbing layer and before preparing other functional layers on the perovskite light absorbing layer, it also includes performing a second annealing; the annealing temperature of the second annealing is 100-150° C., and the annealing time is 15-35 min.

[0016] In some embodiments, the perovskite light absorbing layer is formed by a perovskite precursor solution; the perovskite precursor solution includes: a perovskite material, poly (N-isopropylacrylamide), and a solvent; and the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml.

[0017] The present application also provides a photovoltaic cell assembly, including the above-mentioned perovskite solar cell; and / or The perovskite solar cell prepared by the above method.

[0018] An embodiment of the present application also provides a photovoltaic system, including the above-mentioned photovoltaic cell assembly.

[0019] The above technical solution adopted in the embodiment of the present application may have the following advantages: Adding poly (N-isopropylacrylamide) to the HTL precursor solution can increase the viscosity of the HTL precursor solution and reduce the fluidity of the HTL precursor solution. In the process of coating the HTL precursor solution over a large area, poly (N-isopropylacrylamide) can also promote the uniform distribution of the single-molecule self-assembled materials in the HTL precursor solution, thereby optimizing the film formation of the self-assembled monolayer. Poly (N-isopropylacrylamide) can also effectively alleviate the phenomenon of SAM micelle agglomeration, further promoting the uniform distribution of the single-molecule self-assembled materials. At the same time, poly (N-isopropylacrylamide) can also assist in passivating the free Pb at the perovskite interface. + , which facilitates the formation of a large-area and dense perovskite light absorption layer, thereby helping to reduce the defects at the interface between the perovskite light absorption layer and the self-assembled monolayer, and is beneficial to the transmission of holes, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1 is a schematic diagram of the structure of a perovskite solar cell provided in an embodiment of the present application; Figure 2 is a schematic structural diagram of a perovskite solar cell assembly provided in an embodiment of the present application; Figure 3 is a SEM image of the perovskite light absorption layer provided in Example 1 of the present application; Figure 4 is a SEM image of the perovskite light absorption layer provided in Comparative Example 1 of the present application; Description of reference numerals: 1. Conductive substrate; 2. Self-assembled monolayer; 3. Perovskite light absorption layer; 4. Electron transport layer; 5. Hole blocking layer; 6. Metal electrode. DETAILED DESCRIPTION

[0022] 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.

[0023] 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 disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The present application aims to provide a perovskite solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. Adding poly (N-isopropylacrylamide) to an HTL precursor solution can increase the viscosity of the HTL precursor solution and reduce the fluidity of the HTL precursor solution. In the process of coating the HTL precursor solution over a large area, poly (N-isopropylacrylamide) can also promote the uniform distribution of the single-molecule self-assembled material in the HTL precursor solution, thereby optimizing the film formation of the self-assembled monolayer. Poly (N-isopropylacrylamide) can also effectively alleviate the phenomenon of SAM micelle agglomeration, further promote the uniform distribution of the single-molecule self-assembled material, and poly (N-isopropylacrylamide) can also assist in passivating the free Pb + , which facilitates the formation of a large-area and dense perovskite light absorption layer, thereby helping to reduce the defects at the interface between the perovskite light absorption layer and the self-assembled monolayer, and is beneficial to the transmission of holes, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of perovskite solar cells.

[0028] Below, exemplary embodiments of 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.

[0029] The embodiment of the present application provides a perovskite solar cell, comprising: a self-assembled monolayer; the self-assembled monolayer is formed by a HTL precursor solution; the HTL precursor solution comprises SAM, poly (N-isopropylacrylamide), and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

[0030] In the embodiment of the present application, the degree of polymerization (n) of poly N-isopropylacrylamide (NIPAM) may be 50-500, the monomer molecular weight of poly N-isopropylacrylamide (NIPAM) is 113.16 g / mol, and the molecular weight of poly N-isopropylacrylamide (NIPAM) may be 113.16 g / molX50-113.16 g / molX500. The degree of polymerization (n) of poly N-isopropylacrylamide (NIPAM) may be controlled according to actual needs.

[0031] In the embodiment of the present application, the thickness of the self-assembled monolayer can be 10-100 nm (for example, 20 nm, 30 nm, 40 nm, 60 nm, 80 nm, 100 nm). The preparation method of the self-assembled monolayer can include one or more of a slit coating method, a spin coating method, and a blade coating method. SAM includes: MeO-2PACZ ([2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid), 2PACZ ([2-(9H-carbazole-9-yl)ethyl]phosphonic acid), Me-4PACZ ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid), porphyrin-SAMs (porphyrin-SAMs are derivatives of porphyrin, comprising a porphyrin macrocyclic structure and a carboxylic acid group). In the embodiment of the present application, the amount of SAM and poly (N-isopropylacrylamide) added in the HTL precursor solution can be limited according to actual needs.

[0032] In an embodiment of the present application, the organic solvent includes one or more of ethanol, isopropanol, N-methylpyrrolidone (NMP), 2-mercaptoethanol (2-ME), dimethyl sulfoxide (DMSO), diphenyl sulfoxide (DPSO), N,N-dimethylformamide (DMF), acetonitrile (ACN), dimethylacetamide (DMAc), N,N'-dimethylpropylene urea (DMPU), and 1,4-butyrolactone.

[0033] In the embodiment of the present application, the perovskite solar cell also includes a conductive substrate, a perovskite light absorbing layer, and a self-assembled monolayer, a perovskite light absorbing layer, and other functional layers arranged on the perovskite light absorbing layer are sequentially stacked on the conductive substrate. The perovskite light absorbing layer is made of a perovskite material. The thickness of the perovskite light absorbing layer can be 300-800nm. The perovskite material is an ABX3 structure; the A is a monovalent cation; the B is a divalent cation; the X is a monovalent anion. More specifically, A includes but is not limited to a mixture of one or more monovalent cations of cesium (Cs), rubidium (Rb), methylamine (CH3NH3), and guanidine (CH2(NH2)2); B includes but is not limited to a mixture of one or more divalent cations of lead (Pb), copper (Cu), zinc (Zn), gallium (Ga), tin (Sn), and calcium (Ca); X includes but is not limited to a mixture of one or more monovalent anions of iodine (I), bromine (Br), chlorine (Cl), fluorine (F), and thiocyanate ion (SCN).

[0034] In the embodiment of the present application, the preparation method of the perovskite light absorbing layer is one or more of spin coating, scraper coating, evaporation, printing, spraying, spray pyrolysis, and slit coating; that is, the perovskite light absorbing layer is formed on the upper surface of the self-assembled monolayer by spin coating, scraper coating, etc.; different preparation methods will also have some influence on the crystallization of the perovskite light absorbing layer, and the corresponding preparation method can be selected according to actual needs. When the perovskite light absorbing layer is obtained by coating the upper surface of the self-assembled monolayer by one-step spin coating or slit coating, the coating speed can be 4000-5000 rpm / min (for example, 4000 rpm / min, 4500 rpm / min, 5000 rpm / min), and the coating time can be 30-40s (for example, 30s, 35s, 40s).

[0035] In the embodiment of the present application, adding poly N-isopropylacrylamide to the HTL precursor solution can increase the viscosity of the HTL precursor solution and reduce the fluidity of the HTL precursor solution. In the process of coating the HTL precursor solution on a large area, poly N-isopropylacrylamide can also promote the uniform distribution of the single-molecule self-assembled material in the HTL precursor solution, thereby optimizing the film formation of the self-assembled monolayer; poly N-isopropylacrylamide can also effectively alleviate the phenomenon of SAM micelle agglomeration, further promote the uniform distribution of the single-molecule self-assembled material, and poly N-isopropylacrylamide can also assist in passivating the free Pb + , which facilitates the formation of a large-area and dense perovskite light absorption layer, thereby helping to reduce the defects at the interface between the perovskite light absorption layer and the self-assembled monolayer, and is beneficial to the transmission of holes, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of perovskite solar cells.

[0036] In an optional embodiment, in the HTL precursor solution, the concentration of the SAM is 0.2-0.6 mg / ml (e.g., 0.2 mg / ml, 0.3 mg / ml, 0.4 mg / ml, 0.5 mg / ml, 0.6 mg / ml); And / or, in the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.2-2.5 mg / ml (e.g., 0.2 mg / ml, 0.4 mg / ml, 0.6 mg / ml, 0.8 mg / ml, 1.0 mg / ml, 1.2 mg / ml, 1.4 mg / ml, 1.6 mg / ml, 1.8 mg / ml, 2.0 mg / ml, 2.3 mg / ml, 2.5 mg / ml).

[0037] In the embodiments of the present application, optimizing the addition amount of SAM and / or poly (N-isopropylacrylamide) in the HTL precursor solution helps to enhance the interaction between SAM and poly (N-isopropylacrylamide), facilitates the uniform distribution of SAM and poly (N-isopropylacrylamide), can effectively alleviate the phenomenon of SAM micelle agglomeration, further improves the film-forming quality of the prepared self-assembled monolayer, and thus improves the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0038] In an optional embodiment, in the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.4-2.0 mg / ml (for example, 0.4 mg / ml, 0.6 mg / ml, 0.8 mg / ml, 1.0 mg / ml, 1.2 mg / ml, 1.4 mg / ml, 1.6 mg / ml, 1.8 mg / ml, 2.0 mg / ml).

[0039] In the embodiments of the present application, optimizing the amount of poly (N-isopropylacrylamide) added in the HTL precursor solution helps to enhance the interaction between SAM and poly (N-isopropylacrylamide), facilitates the uniform distribution of SAM and poly (N-isopropylacrylamide), can effectively alleviate the phenomenon of SAM micelle agglomeration, further improves the film-forming quality of the prepared self-assembled monolayer, and thus improves the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0040] In an optional embodiment, the organic solvent includes N,N-dimethylformamide and a polar solvent; the polar solvent is one or more of ethanol and isopropanol.

[0041] In the embodiments of the present application, the composition of the organic solvent in the HTL precursor solution is optimized, which helps to improve the dissolution effect of SAM and poly (N-isopropylacrylamide), strengthen the interaction between SAM and poly (N-isopropylacrylamide), facilitate the uniform distribution of SAM and poly (N-isopropylacrylamide), effectively alleviate the phenomenon of SAM micelle agglomeration, and further improve the film quality of the prepared self-assembled monolayer, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0042] In an optional embodiment, the volume ratio of the polar solvent to the N,N-dimethylformamide in the organic solvent is 1-9:1 (eg, 1:1, 7:3, 9:1).

[0043] In the embodiments of the present application, the ratio of each component of the organic solvent in the HTL precursor solution is optimized, the dissolution effect of SAM and poly (N-isopropylacrylamide) is further improved, the interaction between SAM and poly (N-isopropylacrylamide) is strengthened, the uniform distribution of SAM and poly (N-isopropylacrylamide) is facilitated, the phenomenon of SAM micelle agglomeration can be effectively alleviated, and the film quality of the prepared self-assembled monolayer is further improved, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0044] In an optional embodiment, it further comprises a perovskite light absorbing layer, wherein the perovskite light absorbing layer is disposed on the self-assembled monolayer; The perovskite light absorption layer is formed by a perovskite precursor solution; the perovskite precursor solution comprises: a perovskite material and a solvent; Wherein, the perovskite material includes any one of FAMAPbI, FACsPbI3, and FAMACsPbI3; The solvent includes any one of a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide and a mixed solution of γ-butyrolactone and N-methylpyrrolidone; the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide in the mixed solution of N,N-dimethylformamide and dimethyl sulfoxide is 3-5:1 (for example, 3:1, 4:1, 5:1); the volume ratio of γ-butyrolactone to N-methylpyrrolidone in the mixed solution of γ-butyrolactone and N-methylpyrrolidone is (for example, 3:1, 4:1, 5:1).

[0045] In the embodiments of the present application, by optimizing the type of perovskite material, adjusting the selection and ratio of the solvent, and optimizing the crystallization quality and morphology of the perovskite light absorption layer, the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell can be further improved.

[0046] In an optional embodiment, the perovskite precursor solution further comprises poly (N-isopropylacrylamide); the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml (eg, 0.1 mg / ml, 0.2 mg / ml, 0.3 mg / ml).

[0047] In the embodiment of the present application, by doping the polymer poly (N-isopropylacrylamide) into the perovskite precursor solution, the grain growth of the perovskite light absorption layer can be regulated while also achieving the effect of body passivation, thereby further improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0048] In an optional embodiment, the perovskite solar cell further includes a conductive substrate, a perovskite light absorption layer, an electron transport layer, a hole blocking layer, and a metal electrode; Wherein, the self-assembled monolayer, the perovskite light absorption layer, the electron transport layer, the hole blocking layer, and the metal electrode are sequentially stacked on the conductive substrate.

[0049] In the embodiment of the present application, other functional layers may also be included. The required functional layers may be introduced according to actual needs to achieve specific functions. The conductive substrate includes one or more of FTO glass, ITO glass, and a flexible ITO conductive substrate. The material of the hole blocking layer may be BCP (Bathocuproine, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), and the preparation method of the hole blocking layer may include one or more of a slit coating method, a spin coating method, and a scraping method. The thickness of the hole blocking layer may be 8-15nm (for example, 8nm, 10nm, 12nm, 15nm). The electron transport layer may be made of titanium oxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), fullerene (C 60 ), graphene, fullerene derivatives (PCBM) and other one or more n-type semiconductor materials, the electron transport layer can be prepared by deposition methods including but not limited to electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition, spin coating, scraping and the like. The thickness of the electron transport layer can be 20-40nm (for example, 20nm, 30nm, 40nm). Metal electrode: gold, palladium, silver, titanium, chromium, nickel, aluminum, copper, indium tin oxide (ITO), indium zinc oxide (IZO) and the like can be used. The thickness of the metal electrode can be 60-100nm (for example, 60nm, 80nm, 100nm).

[0050] In the embodiments of the present application, various performances of large-area perovskite solar cells are improved by doping poly (N-isopropylacrylamide) in the HTL precursor solution, which has the advantages of simple preparation process, low material cost, obvious effect of regulating the growth of perovskite thin film crystals, and is conducive to commercial production.

[0051] The embodiment of the present application also provides a method for preparing a perovskite solar cell, comprising: sequentially preparing a self-assembled monolayer and a perovskite light absorption layer on a conductive substrate; the self-assembled monolayer is formed by a HTL precursor solution; the HTL precursor solution comprises SAM, poly (N-isopropylacrylamide), and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

[0052] In the embodiments of the present application, various performances of large-area perovskite solar cells are improved by doping poly (N-isopropylacrylamide) in the HTL precursor solution, which has the advantages of simple preparation process, low material cost, obvious effect of regulating the growth of perovskite thin film crystals, and is conducive to commercial production.

[0053] In an optional embodiment, after preparing the self-assembled monolayer and before preparing the perovskite light absorbing layer, the method further includes performing a first annealing; the annealing temperature of the first annealing is 100-120° C. (for example, 100° C., 110° C., 120° C.), and the annealing time is 10-15 min (for example, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min); And / or, after preparing the perovskite light absorbing layer and before preparing other functional layers on the perovskite light absorbing layer, it also includes performing a second annealing; the annealing temperature of the second annealing is 100~150℃ (for example, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃), and the annealing time is 15~35min (for example, 15min, 20min, 25min, 30min, 35min).

[0054] In the embodiments of the present application, the annealing process of the self-assembled monolayer is optimized, which can effectively alleviate the phenomenon of SAM micelle agglomeration, improve the film-forming quality of the prepared self-assembled monolayer, and further improve the crystallization quality and morphology of the perovskite light absorption layer; the annealing process of the perovskite light absorption layer is optimized, which can improve the crystallization quality and morphology of the prepared perovskite light absorption layer, and is beneficial to improving the photoelectric conversion rate of the perovskite solar cell.

[0055] In an optional embodiment, the perovskite light absorption layer is formed by a perovskite precursor solution; the perovskite precursor solution includes: a perovskite material, poly (N-isopropylacrylamide), and a solvent; the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml (for example, 0.1 mg / ml, 0.2 mg / ml, 0.3 mg / ml).

[0056] In the application example, by doping the polymer poly (N-isopropylacrylamide) into the perovskite precursor solution, the grain growth of the perovskite light absorption layer can be regulated while also achieving the effect of body passivation, which can further improve the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0057] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0058] Example 1 A perovskite solar cell, such as Figure 1 As shown, it includes: a conductive substrate 1, a self-assembled monolayer 2, a perovskite light absorption layer 3, an electron transport layer 4, a hole blocking layer 5, and a metal electrode 6 which are stacked in sequence.

[0059] A perovskite solar cell module (area 49cm 2 ),like Figure 2 As shown, the specific preparation process of perovskite solar cell components is: Step 100: Pretreatment of the conductive substrate 1: Using FTO (fluorine-doped SnO2 conductive glass) glass as the conductive substrate 1, the conductive substrate 1 is cleaned; Step 101: placing the conductive substrate 1 in an ultrasonic cleaning instrument, and ultrasonically cleaning the conductive substrate 1 with deionized water, isopropyl alcohol, and ethanol in sequence, each cleaning step lasting 30 minutes, and using a nitrogen (N2) air gun to blow dry the conductive substrate 1 to obtain a cleaned conductive substrate 1; Step 102: performing laser etching on the cleaned conductive substrate 1 to form a P1 groove to obtain an etched substrate; Step 103: treating the etched substrate with UV-zone (ultraviolet ozone) for 10 minutes to obtain a standby substrate; Step 200: Preparation of self-assembled monolayer 2 Step 201: 12 mg of Me-4PACZ ([4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid) was dissolved in 20 ml of ethanol and stirred for 3 h to form a Me-4PACZ solution; Step 202: 40 mg of poly (N-isopropylacrylamide) (the degree of polymerization of poly (N-isopropylacrylamide) is about 150) is dissolved in 10 ml of N,N-dimethylformamide (DMF) solution to obtain a poly (N-isopropylacrylamide) solution; Step 203: Mix the Me-4PACZ solution and the poly (N-isopropylacrylamide) solution in proportion, adjust the concentration of SAM to 0.2 mg / ml, and the concentration of poly (N-isopropylacrylamide) to 0.4 mg / ml, to obtain a HTL precursor solution; Step 204: using a slit coating method, controlling the gap value to be 100 microns, and coating the HTL precursor solution on the substrate to be used at a coating speed of 30 mm / s to obtain a first target substrate; Step 205: annealing the first target substrate at 100° C. for 10 min to form a self-assembled monolayer 2 with a thickness of 10 nm; Step 300: Preparation of perovskite light absorption layer 3 Step 301: 1 mol of Cs 0.15 FA 0.85 PbI3 powder was dissolved in 25 ml of a mixed solvent with a volume ratio of DMF:DMSO = 4:1, and stirred at room temperature until it was completely dissolved to obtain a perovskite precursor solution; Step 302: using a slit coating method, controlling the gap value to be 100 microns, and spin coating the perovskite precursor solution on the self-assembled monolayer 2 at a coating speed of 30 mm / s in an air environment with a relative humidity of 12%, to obtain a second target substrate; Step 303: performing annealing treatment on the second target substrate at a temperature of 130° C. for 30 min to form a perovskite light absorption layer 3 with a thickness of 500 nm; Step 400: Preparation of electron transport layer 4 Step 401: Evaporate a 30 nm thick C film on the perovskite light absorption layer 3 at a rate of 0.5 Å / s. 60 (fullerene) layer as electron transport layer 4; Step 500: Preparation of hole blocking layer 5 Step 501: a BCP (Bathocuproine, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) layer with a thickness of 6 nm is deposited on the electron transport layer 4 at a rate of 0.5 Å / s as a hole blocking layer 5 to obtain a third target substrate; Step 502: performing laser etching on the third target substrate to form a P2 groove to obtain a fourth target substrate; Step 600: Preparation of metal electrode 6 Step 601: using a thermal evaporation gold film coating method to deposit a 100 nm copper electrode as a metal electrode 6 on the fourth target substrate to obtain a fifth target substrate; Step 602: laser-etch the fifth target substrate to form a P3 groove; then perform P4 laser etching on the fifth target substrate to remove the deposited film at the edge of the battery, and encapsulate to obtain the perovskite solar cell module; wherein the P1 groove penetrates the conductive material layer of the conductive substrate 1; the P2 groove sequentially penetrates the self-assembled monolayer 2, the perovskite light absorption layer 3, the electron transport layer 4, and the hole blocking layer 5; the P3 groove penetrates the metal electrode 6; the conductive material layer in the conductive substrate 1 of a perovskite sub-cell is connected to the metal electrode 6 of the next perovskite sub-cell through the P2 groove to complete the series connection between the perovskite sub-cells to form a perovskite solar cell module; specifically, multiple groups of sequentially arranged P1 grooves, P2 grooves, and P3 grooves can be set according to the area size of the perovskite solar cell module to connect multiple perovskite sub-cells in series to form a large-area perovskite solar cell module. The SEM image of the prepared perovskite light absorption layer is shown in FIG. Figure 3 As shown, see Figure 3 It can be seen that the prepared perovskite light absorption layer has fewer holes, uniform grain size distribution, and higher film quality.

[0060] Example 2-Example 3 The perovskite solar cell modules of Examples 2-3 were prepared by referring to the preparation method of Example 1, except that the areas of the perovskite solar cell modules were different. The formulas of the HTL precursor solutions and the areas of the perovskite solar cell modules in Examples 2-3 are shown in Table 1.

[0061] Example 4-Example 14 The perovskite solar cell modules of Examples 4 to 14 were prepared by referring to the preparation method of Example 1, with the only difference being that the formulas of the prepared HTL precursor solutions were different. The formulas of the HTL precursor solutions in Examples 4 to 14 and the areas of the perovskite solar cell modules are shown in Table 1.

[0062] Embodiment 15 The perovskite solar cell module of Example 15 is prepared by referring to the preparation method of Example 1, except that step 205 of Example 15 is: annealing the first target substrate at 95° C. for 15 min to form a self-assembled monolayer 2 with a thickness of 10 nm.

[0063] Example 16 The perovskite solar cell module of Example 16 is prepared by referring to the preparation method of Example 1, except that step 205 of Example 16 is: annealing the first target substrate at 130° C. for 15 min to form a self-assembled monolayer 2 with a thickness of 10 nm.

[0064] Embodiment 17 The perovskite solar cell module of Example 17 is prepared by referring to the preparation method of Example 1, except that, in step 301 of Example 17, 1 mol of Cs 0.15 FA 0.85 PbI3 powder was dissolved in 25 ml of a mixed solvent with a volume ratio of DMF:DMSO=4:1, and then poly (N-isopropylacrylamide) at a concentration of 1 mg / ml was added to make the concentration of poly (N-isopropylacrylamide) in the perovskite precursor solution 0.1 mg / ml. The solution was stirred at room temperature until it was completely dissolved to obtain a perovskite precursor solution.

[0065] Embodiment 18 The perovskite solar cell module of Example 18 was prepared by referring to the preparation method of Example 1, except that step 301 of Example 18 was: 1 mol of Cs 0.15 FA 0.85 PbI3 powder was dissolved in 25 ml of a mixed solvent with a volume ratio of DMF:DMSO=4:1, and then poly (N-isopropylacrylamide) at a concentration of 1 mg / ml was added to make the concentration of poly (N-isopropylacrylamide) in the perovskite precursor solution 0.3 mg / ml. The solution was stirred at room temperature until it was completely dissolved to obtain a perovskite precursor solution.

[0066] Embodiment 19 The perovskite solar cell module of Example 19 is prepared by referring to the preparation method of Example 1, except that step 303 of Example 19 is: annealing the second target substrate at a temperature of 90° C. for 30 min to form a perovskite light absorption layer 3 with a thickness of 500 nm.

[0067] Embodiment 20 The perovskite solar cell module of Example 20 is prepared by referring to the preparation method of Example 1, except that step 303 of Example 20 is: annealing the second target substrate at a temperature of 160° C. for 30 minutes to form a perovskite light absorption layer 3 with a thickness of 500 nm.

[0068] Comparative Example 1 The perovskite solar cell module of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that the formula of the prepared HTL precursor solution was different. The formula of the HTL precursor solution in Comparative Example 1 is shown in Table 1. The SEM image of the prepared perovskite light absorbing layer is shown in Figure 4 As shown, see Figure 4 It can be seen that the prepared perovskite light absorption layer has more and more obvious holes, uneven grain size distribution, poor density and low film quality.

[0069] Comparative Example 2-Comparative Example 3 The perovskite solar cell modules of Comparative Examples 2-3 were prepared by referring to the preparation method of Example 1, with the only differences being: 1) the areas of the perovskite solar cell modules were different; 2) the formulas of the HTL precursor solutions were different; the formulas of the HTL precursor solutions and the areas of the perovskite solar cell modules in Comparative Examples 2-3 are shown in Table 1.

[0070] Comparative Example 4 The perovskite solar cell module of Comparative Example 4 was prepared by referring to the preparation method of Example 1, except that: (1) Step 301 of Comparative Example 4 is: 1 mol of Cs 0.15 FA 0.85 PbI3 powder was dissolved in 25 ml of a mixed solvent with a volume ratio of DMF:DMSO=4:1, and then poly (N-isopropylacrylamide) with a concentration of 1 mg / ml was added to make the concentration of poly (N-isopropylacrylamide) in the perovskite precursor solution 0.1 mg / ml, and stirred at room temperature until it was completely dissolved to obtain a perovskite precursor solution; (2) The formula of the HTL precursor solution prepared in Comparative Example 4 is different. The formula of the HTL precursor solution in Comparative Example 1 is shown in Table 1.

[0071] Table 1 Formulas and component areas of HTL precursor solutions of Examples and Comparative Examples Table 1

[0072] The following is a performance test of the perovskite solar cell modules provided in Examples 1-20 and Comparative Examples 1-4 of the present application. The test results are shown in Table 2.

[0073] Table 2 Performance test results of perovskite solar cell modules of Examples 1-20 and Comparative Examples 1-4

[0074] Referring to the battery performance test results of Examples 1-20 and Comparative Examples 1-4, it can be seen that adding poly (N-isopropylacrylamide) to the HTL precursor solution can increase the viscosity of the HTL precursor solution and reduce the fluidity of the HTL precursor solution. In the process of coating the HTL precursor solution over a large area, poly (N-isopropylacrylamide) can also promote the uniform distribution of the single-molecule self-assembled material in the HTL precursor solution, thereby optimizing the film formation of the self-assembled monolayer. Poly (N-isopropylacrylamide) can also effectively alleviate the phenomenon of SAM micelle agglomeration, further promote the uniform distribution of the single-molecule self-assembled material, and poly (N-isopropylacrylamide) can also assist in passivating the free Pb at the perovskite interface. +, which facilitates the formation of a large and dense perovskite light absorption layer, thereby helping to reduce defects at the interface between the perovskite light absorption layer and the self-assembled monolayer, and is beneficial to the transmission of holes, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of perovskite solar cells.

[0075] Referring to the battery performance test results of Examples 1 and 4-6, it can be seen that optimizing the addition amount of SAM and / or poly (N-isopropylacrylamide) in the HTL precursor solution is helpful to enhance the interaction between SAM and poly (N-isopropylacrylamide), facilitate the uniform distribution of SAM and poly (N-isopropylacrylamide), effectively alleviate the phenomenon of SAM micelle agglomeration, and further improve the film-forming quality of the prepared self-assembled monolayer, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0076] Referring to the battery performance test results of Examples 1 and 11-12, it can be seen that optimizing the composition of the organic solvent in the HTL precursor solution is helpful to improve the dissolution effect of SAM and poly (N-isopropylacrylamide), strengthen the interaction between SAM and poly (N-isopropylacrylamide), facilitate the uniform distribution of SAM and poly (N-isopropylacrylamide), effectively alleviate the phenomenon of SAM micelle agglomeration, and further improve the film quality of the prepared self-assembled monolayer, thereby improving the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0077] Referring to the battery performance test results of Examples 1 and 8-10, it can be seen that by optimizing the ratio of the components of the organic solvent in the HTL precursor solution, the dissolution effect of SAM and poly (N-isopropylacrylamide) is further improved, the interaction between SAM and poly (N-isopropylacrylamide) is strengthened, and the uniform distribution of SAM and poly (N-isopropylacrylamide) is facilitated, which can effectively alleviate the phenomenon of SAM micelle agglomeration, further improve the film quality of the prepared self-assembled monolayer, and thus improve the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0078] Referring to the battery performance test results of Examples 1 and 17-18, it can be seen that by doping the polymer poly (N-isopropylacrylamide) into the perovskite precursor solution, the grain growth of the perovskite light absorption layer can be regulated while also achieving a body passivation effect, which can further improve the short-circuit current density, open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell.

[0079] Referring to the battery performance test results of Examples 1, 15-16, and 19-20, it can be seen that optimizing the annealing process of the self-assembled monolayer can effectively alleviate the phenomenon of SAM micelle agglomeration, improve the film-forming quality of the prepared self-assembled monolayer, and thus improve the crystallization quality and morphology of the perovskite light absorption layer; optimizing the annealing process of the perovskite light absorption layer can improve the crystallization quality and morphology of the prepared perovskite light absorption layer, which is beneficial to improving the photoelectric conversion rate of the perovskite solar cell.

[0080] The embodiment of the present application may provide a photovoltaic cell assembly, including the above-mentioned perovskite solar cell; and / or The perovskite solar cell prepared by the above method has the same advantages as the above perovskite solar cell.

[0081] The embodiment of the present application can provide a photovoltaic system, including the above-mentioned photovoltaic cell assembly. The advantages of the above-mentioned photovoltaic cell assembly are also possessed by the photovoltaic system, which will not be repeated here. The above-mentioned 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 a junction box. 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.

[0082] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, 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 spatial relative descriptions used here are interpreted accordingly.

[0083] 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.

[0084] It should also be noted that "one embodiment", "another embodiment", "embodiment", 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. Further, when describing a specific feature, structure or characteristic 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.

[0085] 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.

[0086] 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 perovskite solar cell, characterized in that: include: Self-assembled monolayers; The self-assembled monolayer is formed from a HTL precursor solution; The HTL precursor solution includes SAM, poly (N-isopropylacrylamide) and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

2. The perovskite solar cell according to claim 1, characterized in that In the HTL precursor solution, the concentration of SAM is 0.2-0.6 mg / ml; And / or, in the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.2-2.5 mg / ml.

3. The perovskite solar cell according to claim 2, characterized in that: In the HTL precursor solution, the concentration of the poly (N-isopropylacrylamide) is 0.4-2.0 mg / ml.

4. The perovskite solar cell according to claim 1, characterized in that: The organic solvent includes N,N-dimethylformamide and a polar solvent; the polar solvent is one or more of ethanol and isopropanol.

5. The perovskite solar cell according to claim 4, characterized in that: The volume ratio of the polar solvent to the N,N-dimethylformamide in the organic solvent is 1-9:

1.

6. The perovskite solar cell according to claim 1, characterized in that: It also includes a perovskite light absorbing layer, wherein the perovskite light absorbing layer is disposed on the self-assembled monolayer; The perovskite light absorbing layer is formed from a perovskite precursor solution; The perovskite precursor solution comprises: a perovskite material and a solvent; Wherein, the perovskite material includes any one of FAMAPbI, FACsPbI3, and FAMACsPbI3; The solvent includes any one of a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide and a mixed solution of γ-butyrolactone and N-methylpyrrolidone; the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide in the mixed solution of N,N-dimethylformamide and dimethyl sulfoxide is 3-5:1; the volume ratio of γ-butyrolactone to N-methylpyrrolidone in the mixed solution of γ-butyrolactone and N-methylpyrrolidone is 3-5:

1.

7. The perovskite solar cell according to claim 6, characterized in that: The perovskite precursor solution also includes poly (N-isopropylacrylamide); the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml.

8. The perovskite solar cell according to claim 1, characterized in that: It also includes a conductive substrate, a perovskite light absorption layer, an electron transport layer, a hole blocking layer, and a metal electrode; Wherein, the self-assembled monolayer, the perovskite light absorption layer, the electron transport layer, the hole blocking layer, and the metal electrode are sequentially stacked on the conductive substrate.

9. A method for preparing a perovskite solar cell, characterized in that: include: sequentially preparing a self-assembled monolayer and a perovskite light absorbing layer on a conductive substrate; The self-assembled monolayer is formed from a HTL precursor solution; The HTL precursor solution includes SAM, poly (N-isopropylacrylamide) and an organic solvent; The SAM includes: one or more of a single-molecule self-assembly material containing a phosphoric acid group and a single-molecule self-assembly material containing a carboxylic acid group.

10. The method for preparing a perovskite solar cell according to claim 9, characterized in that: After preparing the self-assembled monolayer and before preparing the perovskite light absorbing layer, the method further comprises performing a first annealing; the annealing temperature of the first annealing is 100-120° C., and the annealing time is 10-15 min; And / or, after preparing the perovskite light absorbing layer and before preparing other functional layers on the perovskite light absorbing layer, it also includes performing a second annealing; the annealing temperature of the second annealing is 100-150° C., and the annealing time is 15-35 min.

11. The method for preparing a perovskite solar cell according to claim 9, characterized in that: The perovskite light absorption layer is formed by a perovskite precursor solution; the perovskite precursor solution comprises: a perovskite material, poly (N-isopropylacrylamide) and a solvent; the concentration of the poly (N-isopropylacrylamide) in the perovskite precursor solution is 0.1-0.3 mg / ml.

12. A photovoltaic cell assembly, characterized in that: A perovskite solar cell comprising any one of claims 1 to 8; and / or A perovskite solar cell prepared by the method according to any one of claims 9 to 11.

13. A photovoltaic system, characterized in that: Comprising the photovoltaic cell assembly as claimed in claim 12.

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