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 hole transport layer, an interface modification layer and a perovskite light absorption layer which are stacked in sequence, the hole transport layer is a nickel oxide layer, and the materials of the interface modification layer comprise iminodi (methyl phosphoric acid), Al2O3 nanoparticles and an organic solvent. When the iminodi (methyl phosphoric acid) solution forms a film, the iminodi (methyl phosphoric acid) is anchored on a conductive substrate, the Al2O3 nanoparticles can be uniformly dispersed above a nickel oxide layer to form a layer of carrier transport channel, the wettability of the substrate can be improved, and the iminodi (methyl phosphoric acid) can be chelated with Pb < 2 + > and can also form a hydrogen bond with FA < + > (formamidine) cations, so that the Pb < 2 + > and FA < + > (formamidine) cations can be combined with the conductive substrate. Therefore, the non-radiative recombination loss at the interface is inhibited, the carrier extraction efficiency at the interface is improved, and the perovskite solar cell with higher photoelectric conversion efficiency is prepared in an auxiliary manner.

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 the 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. In addition to engineering the composition and crystallization kinetics of perovskites, interface engineering has been used as an effective tool to improve the efficiency and stability of perovskite solar cells. Recently, self-assembled monolayers (SAMs) have been used as effective hole selection layers (HSLs) to replace traditional organic hole transport layers (HTLs). 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, an ultrathin and efficient hole selection layer (HSL) can be formed. Self-assembled monolayers (SAMs) as hole selection layers (HSL) 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] Although self-assembled monolayers (SAMs) are widely used, they still have some defects. For example, the steric hindrance of the carbazole core limits its formation of a dense monolayer on the substrate, and also hinders the effective passivation of the defects at the bottom of the perovskite film, resulting in problems such as current leakage and serious non-radiative recombination, which have an adverse effect on the performance and stability of optoelectronic devices. At the same time, the poor wettability of SAM molecules will also cause the film quality of perovskite on the surface of self-assembled monolayers (SAMs) to be poor, with more holes and other defects. Using NiO alone x As a hole selective layer (HSL), NiO has good wettability. x When used as a hole selective layer (HSL), the defect density at the interface is high and non-radiative recombination is serious, which seriously affects the performance of the device.

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

[0005] The embodiment of the present application provides a perovskite solar cell and its preparation method, photovoltaic module and photovoltaic system to solve or alleviate the technical problems raised above. The materials of the interface modification layer of the embodiment of the present application include iminobis(methylphosphonic acid), Al2O3 nanoparticles, and organic solvents. Iminobis(methylphosphonic acid) is added to the dispersion of Al2O3 nanoparticles to form an iminobis(methylphosphonic acid) solution. Iminobis(methylphosphonic acid) has a good dissolution effect and does not chemically react with Al2O3 nanoparticles. When forming a film, the iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution will be anchored on the conductive substrate, and the Al2O3 nanoparticles can be evenly dispersed above the nickel oxide layer to form a layer of carrier transmission channel, which can improve the wettability of the substrate, and the two phosphate groups of iminobis(methylphosphonic acid) can react with Pb 2+ Chelation, the amino group of iminobis(methylphosphonic acid) can react with FA + (Formamidine) cations form hydrogen bonds, thereby suppressing non-radiative recombination losses at the interface, improving the carrier extraction efficiency at the interface, and assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency.

[0006] To achieve the above purpose, this application adopts the following technical solutions: A perovskite solar cell comprises: a hole transport layer, an interface modification layer and a perovskite light absorption layer stacked in sequence; The hole transport layer is a nickel oxide layer, and the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

[0007] In some embodiments, the thickness of the hole transport layer is 10-20 nm.

[0008] In some embodiments, the thickness of the interface modification layer is 1-10 nm.

[0009] In some embodiments, the Al2O3 nanoparticles have a particle size of 30-100 nm.

[0010] In some embodiments, the organic solvent includes one or more of ethanol and isopropanol.

[0011] In some embodiments, the interface modification layer is formed by an iminobis(methylphosphonic acid) solution; the iminobis(methylphosphonic acid) solution comprises iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent; In the iminobis(methylphosphonic acid) solution, the concentration of the iminobis(methylphosphonic acid) is 0.4-1.2 mg / ml; And / or, in the iminobis(methylphosphonic acid) solution, the concentration of the Al2O3 nanoparticles is 0.003~0.006cm³ / ml.

[0012] In some embodiments, the perovskite light absorbing 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.

[0013] In some embodiments, a conductive substrate, an electron transport layer, a hole blocking layer, and a metal electrode are also included; Wherein, the hole transport layer, the interface modification layer, 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 hole transport layer, an interface modification layer, and a perovskite light absorption layer on a conductive substrate; Wherein, the hole transport layer is a nickel oxide layer; the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

[0015] In some embodiments, after preparing the hole transport layer and before preparing the interface modification 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 interface modification layer and before preparing the perovskite light absorption layer, the method further comprises performing a second annealing; the annealing temperature of the second 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 third annealing; the annealing temperature of the third annealing is 100-150° C., and the annealing time is 15-35 min.

[0016] 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.

[0017] An embodiment of the present application also provides a photovoltaic system, including the above-mentioned photovoltaic cell assembly.

[0018] The above technical solution adopted in the embodiment of the present application may have the following advantages: The materials of the interface modification layer include iminobis(methylphosphonic acid), Al2O3 nanoparticles, and organic solvents. Iminobis(methylphosphonic acid) is added to the dispersion of Al2O3 nanoparticles to form an iminobis(methylphosphonic acid) solution. Iminobis(methylphosphonic acid) has a good dissolution effect and does not chemically react with Al2O3 nanoparticles. When the film is formed, the iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution will be anchored on the conductive substrate, and the Al2O3 nanoparticles can be evenly dispersed above the nickel oxide layer to form a layer of carrier transmission channel, which can improve the wettability of the substrate, and the two phosphate groups of iminobis(methylphosphonic acid) can react with Pb 2+ Chelation, the amino group of iminobis(methylphosphonic acid) can react with FA + (Formamidine) cations form hydrogen bonds, thereby suppressing non-radiative recombination losses at the interface, improving the carrier extraction efficiency at the interface, and assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 is a schematic diagram of the structure of a perovskite solar cell provided in an embodiment of the present application; Description of reference numerals: 1. Conductive substrate; 2. Self-assembled monolayer; 3. Interface modification layer; 4. Perovskite light absorption layer; 5. Electron transport layer; 6. Hole blocking layer; 7. Metal electrode. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] The present application aims to provide a perovskite solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. The material of the interface modification layer in the perovskite solar cell includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent. Iminobis(methylphosphonic acid) is added to a dispersion of Al2O3 nanoparticles to form an iminobis(methylphosphonic acid) solution. Iminobis(methylphosphonic acid) has a good dissolution effect and does not chemically react with Al2O3 nanoparticles. When forming a film, the iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution will be anchored on a conductive substrate, and the Al2O3 nanoparticles can be evenly dispersed above the nickel oxide layer to form a carrier transmission channel, which can improve the wettability of the substrate, and the two phosphate groups of the iminobis(methylphosphonic acid) can react with Pb 2+ Chelation, the amino group of iminobis(methylphosphonic acid) can react with FA + (Formamidine) cations form hydrogen bonds, thereby suppressing non-radiative recombination losses at the interface, improving the carrier extraction efficiency at the interface, and assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency.

[0027] 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.

[0028] The embodiment of the present application provides a perovskite solar cell, comprising: a hole transport layer, an interface modification layer and a perovskite light absorption layer stacked in sequence; The hole transport layer is a nickel oxide layer, and the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

[0029] In the embodiment of the present application, the thickness of the nickel oxide layer may be 1-20 nm (for example, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm). The preparation method of the nickel oxide layer may include one or more of spin coating, spray coating, electrochemical deposition, physical vapor deposition, and sputtering.

[0030] In the embodiment of the present application, the thickness of the interface modification layer may be 1-20 nm (eg, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm). The preparation method of the interface modification layer may include one or more of slit coating, spin coating, and blade coating.

[0031] In the embodiment of the present application, the perovskite light absorption layer is made of a perovskite material. The thickness of the perovskite light absorption layer can be 300-800nm. The perovskite material is an ABX3 structure; A is a monovalent cation; B is a divalent cation; 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).

[0032] 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).

[0033] In the embodiment of the present application, the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent. Iminobis(methylphosphonic acid) is added to the dispersion of Al2O3 nanoparticles to form an iminobis(methylphosphonic acid) solution. Iminobis(methylphosphonic acid) has a good dissolution effect and does not chemically react with Al2O3 nanoparticles. When the film is formed, the iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution will be anchored on the conductive substrate, and the Al2O3 nanoparticles can be evenly dispersed above the nickel oxide layer to form a layer of carrier transmission channel, which can improve the wettability of the substrate, and the two phosphate groups of the iminobis(methylphosphonic acid) can react with Pb 2+ Chelation, the amino group of iminobis(methylphosphonic acid) can react with FA + (Formamidine) cations form hydrogen bonds, thereby suppressing non-radiative recombination losses at the interface, improving the carrier extraction efficiency at the interface, and assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency.

[0034] In the embodiment of the present application, a nickel oxide layer is selected as a hole transport layer, and the interface of the nickel oxide layer is modified to form a composite hole transport layer structure with excellent performance, which can replace the traditional self-assembled monolayer (SAMs) and nickel oxide layer, and assist in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0035] In an optional embodiment, the hole transport layer has a thickness of 10-20 nm (eg, 10 nm, 15 nm, 20 nm).

[0036] In the embodiments of the present application, the thickness of the hole transport layer is optimized, so as to optimize the contact between the hole transport layer and the interface modification layer, so as to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0037] In an optional embodiment, the thickness of the interface modification layer is 1-10 nm (eg, 1 nm, 5 nm, 10 nm).

[0038] In the embodiments of the present application, the thickness of the interface modification layer is optimized, so as to optimize the contact between the hole transport layer and the interface modification layer, so as to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0039] In an optional embodiment, the particle size of the Al2O3 nanoparticles is 30-100 nm (for example, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm).

[0040] In the embodiments of the present application, the particle size of the Al2O3 nanoparticles is optimized to enhance the dispersion effect of the Al2O3 nanoparticles, and to assist in uniformly dispersing the Al2O3 nanoparticles above the nickel oxide layer to form a layer of carrier transport channels, which can not only improve the wettability of the substrate, but also enhance the carrier extraction efficiency at the interface, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0041] In an optional embodiment, the organic solvent includes one or more of ethanol and isopropanol.

[0042] In the embodiments of the present application, the type of organic solvent is optimized to enhance the dispersion effect of Al2O3 nanoparticles and imidobis(methylphosphonic acid), assist in uniformly dispersing the Al2O3 nanoparticles above the nickel oxide layer, and assist in uniformly anchoring the imidobis(methylphosphonic acid) on the conductive substrate to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0043] In an optional embodiment, the interface modification layer is formed by an iminobis(methylphosphonic acid) solution; the iminobis(methylphosphonic acid) solution comprises iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent; In the iminobis(methylphosphonic acid) solution, the concentration of the iminobis(methylphosphonic acid) is 0.4-1.2 mg / ml (e.g., 0.4 mg / ml, 0.5 mg / ml, 0.6 mg / ml, 0.7 mg / ml, 0.8 mg / ml, 0.9 mg / ml, 1.0 mg / ml, 1.1 mg / ml, 1.2 mg / ml); And / or, in the iminobis(methylphosphonic acid) solution, the concentration of the Al2O3 nanoparticles is 0.003~0.006cm³ / ml (for example, 0.003cm³ / ml, 0.004cm³ / ml, 0.005cm³ / ml, 0.006cm³ / ml).

[0044] In the embodiments of the present application, the content of each component in the iminobis(methylphosphonic acid) solution is optimized to enhance the dispersion effect of Al2O3 nanoparticles and iminobis(methylphosphonic acid), assist in uniformly dispersing the Al2O3 nanoparticles above the nickel oxide layer, and assist in uniformly anchoring the iminobis(methylphosphonic acid) on the conductive substrate to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0045] In an optional embodiment, the perovskite light absorbing 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 3-5:1 (for example, 3:1, 4:1, 5:1).

[0046] 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.

[0047] In an optional embodiment, it further includes a conductive substrate, an electron transport layer, a hole blocking layer, and a metal electrode; Wherein, the hole transport layer, the interface modification layer, the perovskite light absorption layer, the electron transport layer, the hole blocking layer and the metal electrode are sequentially stacked on the conductive substrate.

[0048] 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).

[0049] In the embodiment of the present application, a nickel oxide layer is selected as a hole transport layer, and the interface of the nickel oxide layer is modified to form a composite hole transport layer structure with excellent performance, which can replace the traditional self-assembled monolayer (SAMs) and nickel oxide layer, and assist in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0050] The embodiment of the present application also provides a method for preparing a perovskite solar cell, comprising: sequentially preparing a hole transport layer, an interface modification layer, and a perovskite light absorption layer on a conductive substrate; Wherein, the hole transport layer is a nickel oxide layer; the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

[0051] In the embodiment of the present application, a nickel oxide layer is selected as a hole transport layer, and the interface of the nickel oxide layer is modified to form a composite hole transport layer structure with excellent performance. This structure can replace the traditional self-assembled monolayer (SAMs) and the nickel oxide layer, and assist in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency. The structure has the advantages of simple preparation process, low material cost, and is conducive to commercial production.

[0052] In an optional embodiment, after preparing the hole transport layer and before preparing the interface modification 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 interface modification layer and before preparing the perovskite light absorption layer, the method further comprises performing a second annealing; the annealing temperature of the second 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 third annealing; the annealing temperature of the third 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).

[0053] In the embodiments of the present application, the annealing process of the hole transport layer is optimized, so that the contact between the hole transport layer and the interface modification layer can be optimized, so as to form a composite hole transport layer structure with excellent performance, and assist in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency; the annealing process of the interface modification layer is optimized, so that the contact between the hole transport layer and the interface modification layer can be optimized, so as to form a composite hole transport layer structure with excellent performance, and assist in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency; the annealing process of the perovskite light absorption layer is optimized, so as to 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.

[0054] 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.

[0055] Example 1 A perovskite solar cell, such as Figure 1 As shown, it includes: a conductive substrate 1, a hole transport layer 2, an interface modification layer 3, a perovskite light absorption layer 4, an electron transport layer 5, a hole blocking layer 6, and a metal electrode 7 which are stacked in sequence.

[0056] The specific preparation process of perovskite solar cells is as follows: 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 20 minutes, and using a nitrogen (N2) air gun to blow dry the conductive substrate 1 to obtain a cleaned conductive substrate 1; Step 102: treating the cleaned conductive substrate 1 with UV-zone (ultraviolet ozone) for 20 minutes to obtain a standby substrate; Step 200: Preparation of hole transport layer 2 Step 201: Depositing NiO on the substrate to be used by physical vapor deposition (PVD) x , obtain the first target base; Step 203: annealing the first target substrate at 100° C. for 10 min to form a hole transport layer 2 with a thickness of 15 nm; Step 300: Preparation of interface modification layer 3 Step 301: taking Al2O3 nanoparticles with a particle size of 100 nm and preparing an Al2O3 nanoparticle ethanol dispersion; Step 302: dissolving iminobis(methylphosphonic acid) in ethanol, and then adding the mixture to the Al2O3 nanoparticle ethanol dispersion, stirring to form an iminobis(methylphosphonic acid) solution; the concentration of iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution is 0.8 mg / ml, and the concentration of the Al2O3 nanoparticles is 0.005 cm³ / ml; Step 303: spin-coating the iminobis(methylphosphonic acid) solution on the hole transport layer 2 at a rotation speed of 3000 rpm to obtain a second target substrate; Step 304: annealing the second target substrate at 100° C. for 10 min to form an interface modification layer 3 with a thickness of 10 nm; Step 400: Preparation of perovskite light absorption layer 4 Step 401: dissolving 1.2 mol of FAPbI3 perovskite solution in 1 ml of a solvent having a volume ratio of DMF:NMP=4:1, and stirring for 2 h to obtain a perovskite precursor solution; Step 402: using a one-step spin coating method, the perovskite precursor solution is spin coated on the interface modification layer 3 at a coating speed of 5000 rpm for 30 seconds, and 300 microliters of anisole is quickly added dropwise on the surface of the perovskite layer 5 seconds before the end of the spin coating deposition to form a perovskite wet film, thereby obtaining a third target substrate; Step 403: performing annealing treatment on the third target substrate at an annealing temperature of 150° C. for 15 min to form a perovskite light absorption layer 4 with a thickness of 500 nm; Step 500: Preparation of electron transport layer 5 Step 501: Evaporate a C film with a thickness of 30 nm on the perovskite light absorption layer 4 at a rate of 0.5 Å / s. 60 (fullerene) layer as electron transport layer 5; Step 600: Preparation of hole blocking layer 6 Step 601: 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 5 at a rate of 0.5 Å / s as a hole blocking layer 6; Step 700: Preparation of metal electrode 7 Step 701: A 110 nm thick silver electrode is deposited on the hole blocking layer 6 as the metal electrode 7 by using a thermal evaporation gold film coating method, thereby obtaining the perovskite solar cell.

[0057] Example 2-Example 5 The perovskite solar cells of Examples 2 to 5 were prepared by referring to the preparation method of Example 1, except that the thickness of the hole transport layer 2 prepared in step 300 was different. The thickness of the hole transport layer 2 in Examples 2 to 5 is shown in Table 1.

[0058] Example 6-Example 7 The perovskite solar cells of Examples 6 and 7 were prepared by referring to the preparation method of Example 1, except that the thickness of the interface modification layer was different. The thickness of the interface modification layer in Examples 6 and 7 is shown in Table 1.

[0059] Example 8-Example 9 The perovskite solar cells of Examples 8-9 were prepared by referring to the preparation method of Example 1, with the only difference being that the particle sizes of the Al2O3 nanoparticles in the interface modification layer were different. The particle size data of the Al2O3 nanoparticles in the interface modification layer in Examples 8-9 are shown in Table 1.

[0060] Example 10-Example 13 The perovskite solar cells of Examples 10 to 13 were prepared by referring to the preparation method of Example 1, except that the contents of the components in the iminobis(methylphosphonic acid) solution were different. The contents of the components in the iminobis(methylphosphonic acid) solution in Examples 10 to 13 are shown in Table 1.

[0061] Embodiment 14 The perovskite solar cell of Example 14 is prepared by referring to the preparation method of Example 1, except that step 203 of Example 14 is: annealing the first target substrate at 90° C. for 15 min to form a self-assembled monolayer 2 with a thickness of 10 nm.

[0062] Embodiment 15 The perovskite solar cell of Example 15 is prepared by referring to the preparation method of Example 1, except that step 203 of Example 15 is: annealing the first target substrate at 130° C. for 10 min to form a self-assembled monolayer 2 with a thickness of 10 nm.

[0063] Example 16 The perovskite solar cell of Example 16 is prepared by referring to the preparation method of Example 1, except that step 304 of Example 16 is: annealing the second target substrate at 90° C. for 15 min to form an interface modification layer 3 with a thickness of 10 nm.

[0064] Embodiment 17 The perovskite solar cell of Example 17 is prepared by referring to the preparation method of Example 1, except that step 304 of Example 17 is: annealing the second target substrate at 130° C. for 10 min to form an interface modification layer 3 with a thickness of 10 nm.

[0065] Embodiment 18 The perovskite solar cell of Example 18 is prepared by referring to the preparation method of Example 1, except that step 403 of Example 18 is: annealing the third target substrate at a temperature of 90° C. for 35 min to form a perovskite light absorption layer 4 with a thickness of 500 nm.

[0066] Embodiment 19 The perovskite solar cell of Example 19 is prepared by referring to the preparation method of Example 1, except that step 403 of Example 19 is: annealing the third target substrate at a temperature of 160° C. for 15 min to form a perovskite light absorption layer 4 with a thickness of 500 nm.

[0067] Comparative Example 1 The perovskite solar cell of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that the interface modification layer 3 was not prepared, that is, the perovskite solar cell of Comparative Example 1 was not provided with the interface modification layer 3.

[0068] Comparative Example 2 The perovskite solar cell of Comparative Example 2 was prepared by referring to the preparation method of Example 1, except that, steps 200 to 203 were as follows: Me-4PACZ ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid) was dissolved in ethanol, stirred, and a Me-4PACZ solution with a concentration of 0.6 mg / ml was prepared; the Me-4PACZ solution was coated on the stand-by substrate at a coating speed of 3000 rpm by spin coating to obtain a first target substrate; the first target substrate was annealed at 100° C. for 10 min to form a hole transport layer 2 with a thickness of 10 nm; that is, the hole transport layer 2 of the perovskite solar cell of Comparative Example 2 was a self-assembled monolayer (SAMs), and the perovskite solar cell of Comparative Example 2 was provided with an interface modification layer 3.

[0069] Comparative Example 3 The perovskite solar cell of Comparative Example 3 was prepared by referring to the preparation method of Example 1, except that: 1) Step 200 to Step 203 are: Me-4PACZ ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid) was dissolved in ethanol, stirred, and a Me-4PACZ solution with a concentration of 0.6 mg / ml was prepared; the Me-4PACZ solution was coated on the standby substrate at a coating speed of 3000 rpm by spin coating to obtain a first target substrate; the first target substrate was annealed at 100° C. for 10 min to form a hole transport layer 2 with a thickness of 10 nm; 2) The interface modification layer 3 is not prepared; that is, the hole transport layer 2 of the perovskite solar cell of Comparative Example 3 is a self-assembled monolayer (SAMs), and the perovskite solar cell of Comparative Example 3 is not provided with the interface modification layer 3.

[0070] Table 1 Parameters of the embodiment Table 1

[0071] The following is a performance test of the perovskite solar cell modules provided in Examples 1-19 and Comparative Examples 1-3 of the present application. The test results are shown in Table 2.

[0072] Table 2 Performance test results of perovskite solar cell modules of Examples 1-19 and Comparative Examples 1-3

[0073] Referring to the battery performance test results of Examples 1-19 and Comparative Examples 1-3, it can be seen that the material of the interface modification layer in the perovskite solar cell includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent. Iminobis(methylphosphonic acid) is added to the dispersion of Al2O3 nanoparticles to form an iminobis(methylphosphonic acid) solution. Iminobis(methylphosphonic acid) has a good dissolution effect and does not chemically react with Al2O3 nanoparticles. When forming a film, the iminobis(methylphosphonic acid) in the iminobis(methylphosphonic acid) solution will be anchored on the conductive substrate, and the Al2O3 nanoparticles can be evenly dispersed above the nickel oxide layer to form a layer of carrier transmission channel, which can improve the wettability of the substrate, and the two phosphate groups of the iminobis(methylphosphonic acid) can react with Pb 2+ Chelation, the amino group of iminobis(methylphosphonic acid) can react with FA + (Formamidine) cations form hydrogen bonds, thereby suppressing non-radiative recombination losses at the interface, improving the carrier extraction efficiency at the interface, and assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency.

[0074] Referring to the battery performance test results of Examples 1 and 4-5, it can be seen that optimizing the thickness of the hole transport layer can optimize the contact between the hole transport layer and the interface modification layer to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0075] Referring to the battery performance test results of Examples 1 and 6-7, it can be seen that optimizing the thickness of the interface modification layer can optimize the contact between the hole transport layer and the interface modification layer to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0076] Referring to the battery performance test results of Examples 1 and 8-9, it can be seen that optimizing the particle size of Al2O3 nanoparticles can enhance the dispersion effect of Al2O3 nanoparticles, assist in uniformly dispersing the Al2O3 nanoparticles above the nickel oxide layer, and form a layer of carrier transport channels, which can not only improve the wettability of the substrate, but also improve the carrier extraction efficiency at the interface, thereby assisting in the preparation of perovskite solar cells with higher photoelectric conversion efficiency.

[0077] Referring to the battery performance test results of Examples 1 and 10-13, it can be seen that optimizing the content of each component in the iminobis(methylphosphonic acid) solution can improve the dispersion effect of Al2O3 nanoparticles and iminobis(methylphosphonic acid), assist in uniformly dispersing the Al2O3 nanoparticles above the nickel oxide layer, and assist in uniformly anchoring the iminobis(methylphosphonic acid) on the conductive substrate to form a composite hole transport layer structure with better performance, thereby assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency.

[0078] Referring to the battery performance test results of Examples 1 and 14-19, it can be seen that optimizing the annealing process of the hole transport layer can optimize the contact between the hole transport layer and the interface modification layer, thereby facilitating the formation of a composite hole transport layer structure with excellent performance, and assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency; optimizing the annealing process of the interface modification layer can optimize the contact between the hole transport layer and the interface modification layer, thereby facilitating the formation of a composite hole transport layer structure with excellent performance, and assisting in the preparation of a perovskite solar cell with higher photoelectric conversion efficiency; 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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: A hole transport layer, an interface modification layer and a perovskite light absorption layer are stacked in sequence; The hole transport layer is a nickel oxide layer, and the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

2. The perovskite solar cell according to claim 1, characterized in that The thickness of the hole transport layer is 10-20 nm.

3. The perovskite solar cell according to claim 1, characterized in that The thickness of the interface modification layer is 1-10 nm.

4. The perovskite solar cell according to claim 1, characterized in that: The particle size of the Al2O3 nanoparticles is 30-100 nm.

5. The perovskite solar cell according to claim 1, characterized in that: The organic solvent includes one or more of ethanol and isopropanol.

6. The perovskite solar cell according to claim 1, characterized in that: The interface modification layer is formed by an iminobis(methylphosphonic acid) solution; the iminobis(methylphosphonic acid) solution comprises iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent; In the iminobis(methylphosphonic acid) solution, the concentration of the iminobis(methylphosphonic acid) is 0.4-1.2 mg / ml; And / or, in the iminobis(methylphosphonic acid) solution, the concentration of the Al2O3 nanoparticles is 0.003~0.006cm³ / ml.

7. The perovskite solar cell according to claim 1, characterized in that: 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.

8. The perovskite solar cell according to claim 1, characterized in that: It also includes a conductive substrate, an electron transport layer, a hole blocking layer, and a metal electrode; Wherein, the hole transport layer, the interface modification layer, 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: A hole transport layer, an interface modification layer, and a perovskite light absorption layer are sequentially prepared on a conductive substrate; Wherein, the hole transport layer is a nickel oxide layer; the material of the interface modification layer includes iminobis(methylphosphonic acid), Al2O3 nanoparticles, and an organic solvent.

10. The method for preparing a perovskite solar cell according to claim 9, characterized in that: After preparing the hole transport layer and before preparing the interface modification 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 interface modification layer and before preparing the perovskite light absorption layer, the method further comprises performing a second annealing; the annealing temperature of the second 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 third annealing; the annealing temperature of the third annealing is 100-150° C., and the annealing time is 15-35 min.

11. 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 10.

12. A photovoltaic system, characterized in that: Comprising the photovoltaic cell assembly as claimed in claim 11.

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