Amphipathic molecule, and preparation method therefor and use thereof

Abstract

Disclosed in the present application are an amphipathic molecule, and a preparation method therefor and the use thereof. The general chemical structural formula of the amphipathic molecule provided in the present application is represented by formula I: wherein R comprises a Lewis basic group; X1, X2, X3, X4 and X5 independently comprise at least one of hydrogen and halogen atoms; X1, X2, X3, X4 and X5 are not hydrogen at the same time; and n is an integer greater than or equal to 1. The amphipathic molecule of the present application has both a Lewis acid group and a Lewis base group, and such an amphipathic molecule can be used for passivating two defects of a perovskite grain boundary, namely under-coordinated anions and under-coordinated cations; thus, the amphipathic molecule can significantly improve the conversion efficiency and stability of perovskite when being used in a perovskite material.

Description

Amphiphilic molecules and their preparation methods and applications

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 15, 2023, with application number 202310714608.X and invention name “Amphiphilic molecules, preparation methods and applications thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of perovskite technology, and specifically relates to a amphiphilic molecule and its preparation method and application. Background Art

[0003] Perovskites are a class of semiconductor nanomaterials with uniform size and high color purity. Their elemental composition has a crystal structure similar to that of the mineral CaTiO3. Perovskites possess strong light absorption capabilities and a broad absorption range, offering significant advantages in the optoelectronics field. For example, perovskite solar cells (PSCs), which use organic-inorganic hybrid perovskite materials as the light-absorbing layer, have seen rapid development.

[0004] In an ideal perovskite crystal structure, each atom has its own corresponding position. However, actual perovskites produce surface defects due to the influence of crystal growth and post-processing. The grain boundary defects formed in perovskite crystals can easily lead to non-radiative recombination of carriers, thus affecting their photoelectric conversion efficiency.

[0005] Summary of the Invention

[0006] In view of the above problems, the present application provides a amphiphilic molecule and its preparation method and application, aiming to solve the technical problem of how to reduce perovskite grain boundary defects.

[0007] In a first aspect, the embodiments of the present application provide an amphiphilic molecule, the general chemical structure of the amphiphilic molecule is shown in Formula I:

[0008] Wherein, R includes a Lewis basic group, X1, X2, X3, X4, and X5 independently include at least one of hydrogen and halogen atoms, and X1, X2, X3, X4, and X5 are not hydrogen at the same time, and n is an integer greater than or equal to 1.

[0009] The amphiphilic molecule is used to have both a Lewis acid (Lewis Acid, LA) group and a Lewis base (Lewis Base, LB) group. Specifically, in the amphiphilic molecule shown in Formula I, R includes a Lewis base group, and the halogen-substituted benzene ring structure is a Lewis acid group. Such amphiphilic molecules can be used to passivate two defects of the perovskite crystal boundary, namely insufficiently coordinated anions and insufficiently coordinated cations. On the one hand, the halogen-substituted benzene ring structure can receive electrons from the anions at the edge of the perovskite crystal as a Lewis acid group to passivate the insufficiently coordinated anions of the perovskite crystal. On the other hand, the lone electron pair of the Lewis base at the R end can be provided to the insufficiently coordinated cations to passivate the anion vacancy defects of the perovskite crystal; moreover, the moisture resistance of the perovskite can be improved based on the hydrophobicity of the amphiphilic molecule itself. Therefore, the embodiment of the present application provides that amphiphilic molecules can better passivate the surface defects of the perovskite crystal, thereby improving the conversion efficiency and stability of the perovskite.

[0010] In one embodiment, n is 1-9.

[0011] The distance between the R group and the halogen-substituted benzene ring structure is short, and it is not easy to form intermolecular adducts. The amphiphilic molecule can flexibly combine with under-coordinated anions and under-coordinated cations as needed.

[0012] In one embodiment, the Lewis basic group includes at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group.

[0013] The above-mentioned Lewis base groups can bind to under-coordinated cations and provide them with lone electron pairs to passivate the anion vacancy defects in the perovskite crystal.

[0014] In one embodiment, X1, X2, X3, X4, and X5 are the same halogen atoms.

[0015] The fully halogenated benzene ring structure acts as a Lewis acid group, which can better combine with under-coordinated anions to better passivate the under-coordinated anions in the perovskite crystal.

[0016] In one embodiment, the amphiphilic molecule comprises:

[0017] The perfluorinated benzene ring in the amphiphilic molecule serves as the Lewis acid group, which is not only structurally stable and can effectively passivate perovskite grain boundary defects, but also easy to synthesize.

[0018] In a second aspect, the present invention provides a method for preparing an amphiphilic molecule, comprising the following steps:

[0019] The compound represented by formula II is subjected to a hydrogenation reaction to obtain the amphiphilic molecule provided by the first aspect of the embodiment of the present application;

[0020] The amphiphilic molecule of Formula I in the examples of this application can be obtained by hydrogenating the compound of Formula II. This preparation method is not only simple and easy to implement, but also the amphiphilic molecule having Lewis acid groups and Lewis base groups can effectively passivate the grain boundary defects of the perovskite, thereby improving the conversion efficiency and stability of the perovskite.

[0021] In one embodiment, the temperature of the hydrogenation reaction is 60-80° C.; and / or,

[0022] The hydrogenation reaction time is 2 to 8 hours.

[0023] The synthesis of amphiphilic molecules can be well achieved under the above temperature and time conditions.

[0024] In one embodiment, the hydrogenation reaction is carried out in the presence of a rhodium catalyst; and / or,

[0025] The hydrogenation reaction is carried out in an alcohol solvent.

[0026] The addition of the above catalysts can greatly improve the synthesis efficiency of amphiphilic molecules, while alcohol solvents can provide a good environment for the synthesis of amphiphilic molecules.

[0027] In one embodiment, the synthesis steps of the compound shown in Formula II include: subjecting the compound shown in Formula III to a nucleophilic substitution reaction with triethyl phosphite, and then reacting the product of the nucleophilic substitution reaction with R-(CH2) n-1 -CO undergoes addition reaction;

[0028] Wherein, X' is a halogen atom.

[0029] Triethyl phosphite first undergoes a nucleophilic substitution reaction with the halogenated benzene ring hydrocarbon represented by formula III, and then reacts with aldehyde to obtain an HWE (Horner-Wadsworth-Emmons) reaction product, namely, the compound represented by formula II.

[0030] In a third aspect, the embodiments of the present application provide an application, namely, the application of the amphiphilic molecule provided in the first aspect of the embodiments of the present application and / or the amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiments of the present application as a perovskite crystal passivator.

[0031] The amphiphilic molecule shown in Formula I has both Lewis acid groups and Lewis base groups, which can be used to passivate under-coordinated anions and under-coordinated cations at the perovskite grain boundaries. Therefore, it can be used as a perovskite crystal passivator to passivate the grain boundary defects of the perovskite, thereby improving the conversion efficiency and stability of the perovskite.

[0032] In a fourth aspect, an embodiment of the present application provides a perovskite material, which includes a perovskite crystal and an amphiphilic molecule provided in the first aspect of the embodiment of the present application and / or an amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiment of the present application, which is combined with the perovskite crystal.

[0033] Because this amphiphilic molecule has both Lewis acid groups and Lewis base groups and is hydrophobic, it is used in perovskite materials as a passivator to combine with perovskite crystals, thereby passivating the grain boundary defects of the perovskite and improving the conversion efficiency and stability of the perovskite material.

[0034] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.002).

[0035] The amphiphilic molecules at the above ratio can passivate the perovskite crystals well.

[0036] In a fifth aspect, an embodiment of the present application provides a photoelectric device, comprising a perovskite layer, wherein the perovskite layer comprises the perovskite material provided in the fourth aspect of the embodiment of the present application.

[0037] Because the perovskite layer of the optoelectronic device provided in the embodiment of the present application includes a unique perovskite material, such a perovskite layer has fewer grain boundary defects and good moisture resistance, thereby enabling the optoelectronic device to have excellent photoelectric conversion efficiency and stability.

[0038] In one embodiment, the photovoltaic device comprises a solar cell.

[0039] The solar cell uses the perovskite material unique to the embodiment of the present application, which can better convert light energy into electrical energy, so that the solar cell has good photoelectric conversion efficiency and stability.

[0040] In a sixth aspect, an embodiment of the present application provides an electrical device, comprising the optoelectronic device provided in the fifth aspect of the embodiment of the present application.

[0041] By adopting the optoelectronic device provided in the fifth aspect of the embodiment of the present application, such an electrical device has high photoelectric conversion efficiency and good stability, and can work better.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0044] FIG1 is a schematic diagram showing a comparison of the perovskite of an embodiment of the present application before and after passivation by amphiphilic molecules;

[0045] FIG2 is a schematic structural diagram of a solar cell according to an embodiment of the present application;

[0046] Explanation of reference numerals: 1 - first electrode, 2 - hole transport layer, 3 - perovskite layer, 4 - electron transport layer, 5 - second electrode. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0049] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0050] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0052] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more (including two groups), and "multiple sheets" refers to two or more (including two sheets). "At least one" refers to more than one (including one, two, three, etc.).

[0053] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 embodiments of the present application.

[0054] In the description of the embodiments of this application, unless otherwise expressly specified or limited, technical terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this application based on specific circumstances.

[0055] With the dwindling availability of traditional energy resources, the development of new energy sources is gaining increasing attention. Driven by modern society's growing demand for green energy, photovoltaic devices, such as solar cells, which convert light into electricity through the photoelectric effect, have seen rapid development. Currently, solar cells have reached their third generation: perovskite solar cells (PSCs). These cells offer advantages such as high photoelectric conversion efficiency and low power generation costs. They also have the potential to be integrated into buildings, promising alternatives to curtain wall systems for high-rise buildings, enabling both daylighting and power generation.

[0056] Perovskite solar cells utilize perovskite-type organometallic halide semiconductors as light-absorbing materials. Perovskite, a synthetic material, has exploded in popularity since its initial application in photovoltaic power generation due to its excellent performance, low cost, and significant commercial value. The quality of the perovskite layer, the light-absorbing layer in perovskite solar cells, directly impacts the device's conversion efficiency and stability.

[0057] Perovskite is susceptible to surface defects due to the influence of crystal growth and its post-processing process. For example, there are two main types of defects formed at the perovskite grain boundary: (1) insufficient coordination of cations such as divalent cations due to iodide vacancies; (2) insufficient coordination of anions such as halide ions due to cation vacancies resulting in uncoordinated anions at the boundary. The surface defect states formed in perovskite crystals easily lead to non-radiative recombination of carriers, thereby affecting its photoelectric conversion efficiency. Currently, perovskite surface defects can be passivated by molecular modification, but generally, they are modified with molecules with a single property, such as Lewis base molecules. For example, there are reports of modifying perovskite with 1-benzyl-3-hydroxypyridinium chloride (1B3HPC). 1B3HPC, as a Lewis base, can passivate the low-coordination divalent cations (such as Pb) on the perovskite surface that act as Lewis acids. 2+ ), forming Lewis adducts, but they cannot passivate the under-coordinated halide ions, thus improving the performance of solar cells to a limited extent.

[0058] Based on the above considerations, and to simultaneously overcome the multiple defects of current perovskites, the present invention proposes an amphiphilic molecule possessing both Lewis acid and Lewis base groups. This allows for the simultaneous passivation of both types of perovskite defects, thereby further improving the performance of the perovskite. The following technical solution is proposed.

[0059] Amphiphilic molecules

[0060] In a first aspect, the embodiments of the present application provide an amphiphilic molecule, the general chemical structure of the amphiphilic molecule is shown in Formula I:

[0061] Wherein, R includes a Lewis basic group, X1, X2, X3, X4, and X5 independently include at least one of hydrogen and halogen atoms, and X1, X2, X3, X4, and X5 are not hydrogen at the same time, and n is an integer greater than or equal to 1.

[0062] According to the Lewis acids and bases theory, also known as the acid-base electron theory, any substance (molecule, ion, or atomic group) that can accept an electron pair is called a Lewis acid (LA), and any substance (molecule, ion, or atomic group) that can donate an electron pair is called a Lewis base (LB). Lewis acids are electron pair acceptors, and Lewis bases are electron pair donors.

[0063] The amphiphilic molecule shown in the above formula I provided in the embodiments of the present application has both a Lewis acid group and a Lewis base group. Specifically, R includes a Lewis base group that can donate an electron pair, while the halogen-substituted benzene ring structure as a Lewis acid group can accept an electron pair. The amphiphilic molecule provided in the embodiments of the present application can be used to passivate two defects at the perovskite crystal boundary, namely, undercoordinated anions and undercoordinated cations. Specifically: (1) the halogen-substituted benzene ring structure as a Lewis acid group can accept electrons from anions at the edge of the perovskite crystal to passivate the undercoordinated anions of the perovskite crystal, and (2) the lone electron pair of the Lewis base at the R end can be provided to the undercoordinated cation to passivate the anion vacancy defect of the perovskite crystal.

[0064] In one embodiment, in the amphiphilic molecule of formula I provided in the embodiment of the present application, -(CH2)-(CH2) n - is an intermediate carbon chain, connecting the R group and the halogen-substituted benzene ring structure. Specifically, n=1-9, for example, n can be 2, 4, 5, 6, 8, 9, etc. In this way, the distance between the R group and the halogen-substituted benzene ring structure is short, and it is not easy to form intermolecular adducts. The amphiphilic molecule can flexibly combine with under-coordinated anions and under-coordinated cations as needed, thereby better passivating the surface defects of the perovskite crystal, thereby improving the conversion efficiency and stability of the perovskite.

[0065] In one embodiment, in the amphiphilic molecule of Formula I, the Lewis base group in R includes at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group. For example, the Lewis base group may be a 2-thienyl group, a 3-thienyl group, a 2-furyl group, a 3-furyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, or the like, in various attachment configurations.

[0066] Amphiphilic molecules containing the above-mentioned Lewis base groups are used in perovskites because these Lewis base groups can bind to under-coordinated cations and provide lone electron pairs to the bound cations to passivate anion vacancy defects in the perovskite crystal.

[0067] In one embodiment, in the amphiphilic molecule shown in Formula I, X1, X2, X3, X4, and X5 independently include at least one of hydrogen and halogen atoms, and X1, X2, X3, X4, and X5 are not hydrogen at the same time. It can be understood that the halogen-substituted benzene ring structure can be monosubstituted or polysubstituted, or substituted at different positions. As long as the halogen-substituted benzene ring structure formed has the characteristics of a Lewis acid, it is within the scope of protection of this application. Specifically, the halogen atom can be fluorine, chlorine, bromine, iodine, etc.

[0068] In one embodiment, in the amphiphilic molecule of Formula I, X1, X2, X3, X4, and X5 are identical halogen atoms. The fully halogenated benzene ring structure acts as a Lewis acid group, which can better bind to under-coordinated anions to better passivate under-coordinated anions in the perovskite crystal. In one embodiment, the amphiphilic molecule comprises the following structure:

[0069] The perfluorinated benzene ring in the amphiphilic molecule serves as the Lewis acid group, which is not only structurally stable and can effectively passivate perovskite grain boundary defects, but also easy to synthesize.

[0070] Preparation method of amphiphilic molecules

[0071] In a second aspect, the present invention provides a method for preparing an amphiphilic molecule, comprising the following steps:

[0072] The compound represented by formula II is subjected to a hydrogenation reaction to obtain the amphiphilic molecule provided by the first aspect of the embodiment of the present application;

[0073] The compound represented by Formula II is subjected to a hydrogenation reaction, thereby connecting the R group and the halogen-substituted benzene ring structure through a saturated carbon chain to obtain the amphiphilic molecule represented by Formula I in the examples of this application. This preparation method is not only simple and easy to implement, but the resulting amphiphilic molecule, based on Lewis acid groups and Lewis base groups, can effectively passivate surface defects in perovskite crystals, thereby improving the conversion efficiency and stability of perovskite.

[0074] In one embodiment, R, X1, X2, X3, X4, X5 and n in the compound of formula II correspond to R, X1, X2, X3, X4, X5 and n in the amphiphilic molecule of formula I.

[0075] In one embodiment, the temperature of the hydrogenation reaction is 60-80° C. (Celsius); illustratively, the temperature of the addition reaction can be 60° C., 70° C., 75° C., 80° C., etc. The hydrogenation reaction can be well promoted at a temperature of 60-80° C.

[0076] In one embodiment, the hydrogenation reaction time is 2 to 8 hours; illustratively, the addition reaction time can be 2 hours, 4 hours, 5 hours, 6 hours, 8 hours, etc. A hydrogenation reaction time of 2 to 8 hours can fully achieve the synthesis of amphiphilic molecules.

[0077] In one embodiment, the hydrogenation reaction temperature is 60-80° C., and the hydrogenation reaction time is 2-8 hours. Under the above hydrogenation reaction temperature and time conditions, the compound represented by Formula II can fully undergo hydrogenation reaction to efficiently synthesize the amphiphilic molecule.

[0078] In one embodiment, the hydrogenation reaction is carried out in the presence of a rhodium catalyst. The addition of a rhodium catalyst can increase the rate of the addition reaction, thereby significantly improving the synthesis efficiency of the amphiphilic molecule represented by the product formula I. For example, the rhodium catalyst can include tris(triphenylphosphine)rhodium chloride.

[0079] In one embodiment, the hydrogenation reaction can be carried out in an alcoholic solvent. The alcoholic solvent can fully dissolve the raw materials for the hydrogenation reaction. The alcoholic solvent can include ethanol, propanol, etc. Taking ethanol as an example, the compound shown in Formula II is dissolved in ethanol, and after nitrogen is filled, an appropriate amount of catalyst tris(triphenylphosphine) rhodium chloride is added to maintain a certain hydrogen pressure to react and obtain a product.

[0080] In one embodiment, the synthesis steps of the compound shown in Formula II include: subjecting the compound shown in Formula III to a nucleophilic substitution reaction with triethyl phosphite, and then reacting the product of the nucleophilic substitution reaction with R-(CH2) n-1 -CO undergoes addition reaction;

[0081] Wherein, X' is a halogen atom.

[0082] Triethyl phosphite first undergoes a nucleophilic substitution reaction with the halogenated benzene ring hydrocarbon shown in formula III, and the halide ion causes the ethoxy group to break to form a hydrocarbon-substituted diethyl phosphonate derivative. When there is an electron-withdrawing group at the β-position of the halogen atom in the halogenated benzene ring hydrocarbon shown in formula III, the product generates a phosphine ylide under the action of a strong base, which then reacts with the aldehyde R-(CH2) n-1 -CO reacts to obtain a HWE (Horner-Wadsworth-Emmons) reaction product, namely the compound shown in formula II.

[0083] Taking the compound shown in the raw material formula II, X1, X2, X3, X4, and X5 are fluorine atoms, and n=1 as an example. The steps of the method for synthesizing the compound shown in formula II may include: heating C6F5CH2Br and triethyl phosphite under nitrogen protection to carry out a nucleophilic substitution reaction. The product after vacuum distillation is then dissolved in dimethylformamide with sodium methoxide and R-formaldehyde R-CHO and stirred for an addition reaction, and finally purified, dried, and recrystallized to obtain a compound shown in formula II containing a double bond. Subsequently, a hydrogenation reaction is carried out under the catalyst conditions of tri(triphenylphosphine)rhodium chloride to obtain the corresponding amphiphilic molecule. The specific process is as follows:

[0084] application

[0085] In a third aspect, the embodiments of the present application provide an application, namely, the application of the amphiphilic molecule provided in the first aspect of the embodiments of the present application and / or the amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiments of the present application as a perovskite crystal passivator.

[0086] Based on the main presence of two kinds of defects in perovskite crystal boundaries, namely under-coordinated anions and under-coordinated cations, Lewis acids and Lewis bases can passivate these two defects respectively, to enhance perovskite performance. The amphiphilic molecule shown in the formula I designed by the embodiment of the present application has a Lewis acid group and a Lewis base group simultaneously, which can be used to passivate the under-coordinated anions and under-coordinated cations of the perovskite crystal boundaries. At the same time, based on the amphiphilic molecule, there is hydrophobicity, which can improve the moisture-proof stability of perovskite. Therefore, the amphiphilic molecule is used in the synthesis of perovskite as a perovskite crystal passivator, and the surface defects of the perovskite crystal can be passivated, thereby improving the conversion efficiency and stability of perovskite.

[0087] Specifically, the types and preparation methods of the amphiphilic molecules represented by Formula I are described above.

[0088] Perovskite materials

[0089] In a fourth aspect, an embodiment of the present application provides a perovskite material, which includes a perovskite crystal and an amphiphilic molecule provided in the first aspect of the embodiment of the present application and / or an amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiment of the present application, which is combined with the perovskite crystal.

[0090] The amphiphilic molecule shown in the above formula I according to the embodiment of the present application has both a Lewis acid group and a Lewis base group and is hydrophobic. It is used as a passivator in the perovskite material and combines with the perovskite crystal to passivate the grain boundary defects of the perovskite and improve the conversion efficiency and stability of the perovskite material.

[0091] In some embodiments, the perovskite chemical formula of the present invention can be ABX3; wherein A is a monovalent cation, which can be an organic cation or an inorganic cation, and can specifically include CH3NH3 + 、Cs + and CH(NH2)2 + At least one of; B is a divalent cation, specifically including Pb 2+ 、Sn 2+ At least one of; X is a monovalent anion, specifically Cl - Br - and I - At least one of .

[0092] In some embodiments, the divalent cation in the perovskite is Pb 2+ , monovalent anion is I -For example, as shown in Figure 1, before the use of amphiphilic molecules (a in Figure 1), there are two types of defects at the perovskite grain boundary: insufficiently coordinated iodide ions (i.e., lead ion vacancies) and insufficiently coordinated lead ions (i.e., iodide vacancies). After the use of amphiphilic molecules (b in Figure 1), the Lewis acid LA groups at one end of some amphiphilic molecules can bind to insufficiently coordinated iodine ions and passivate the insufficiently coordinated iodine ions in the perovskite crystal by receiving electrons from the iodine ions at the edge of the perovskite crystal; the Lewis base LB groups at one end of another part of the amphiphilic molecules can bind to insufficiently coordinated lead ions and provide lone electron pairs to the bound lead ions to passivate the iodide vacancy defects in the perovskite crystal.

[0093] Because Lewis acids and Lewis bases form adducts, the amphiphilic molecules provided in the embodiments of this application can act as both a Lewis acid and a Lewis base. The Lewis acid end of the amphiphilic molecule flows toward the exposed iodide, while the Lewis base end of the amphiphilic molecule can also flow toward the exposed uncoordinated lead ion. This effectively passivates both grain boundary defects in the perovskite, improving the conversion efficiency and stability of the perovskite material.

[0094] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.002). For example, the molar ratio of the perovskite crystal ABX3 to the amphiphilic molecule can be 1:0.0001, 1:0.0002, 1:0.0005, 1:0.0006, 1:0.0008, 1:0.001, 1:0.0015, 1:0.002, etc. The amphiphilic molecule in the above molar ratio can effectively passivate the perovskite crystal.

[0095] In one embodiment, the amphiphilic molecule shown in Formula I can be added separately as an additive to the perovskite precursor solvent, and subsequently annealed and crystallized to obtain a perovskite material passivated by the amphiphilic molecule. Specifically, a perovskite precursor solution of perovskite ABX3 can be prepared first, and then the amphiphilic molecule is added and stirred evenly, annealed at 80 to 100 ° C for 20 to 40 minutes, and then cooled to room temperature to obtain a perovskite layer, that is, a perovskite material in the form of a film layer. During the annealing and crystallization process, on the one hand, the amphiphilic molecule slows down the crystallization process of the perovskite, thereby increasing the grain size of the perovskite. On the other hand, the amphiphilic molecule having a Lewis acid group and a Lewis base group has a passivation effect on the perovskite grain boundary, thereby reducing the defect density of the perovskite layer, thereby improving the conversion efficiency and stability of the perovskite.

[0096] In the above process, the amount of the amphiphilic molecules added to the perovskite precursor solution can be 0.01 mol% to 0.2 mol% (based on the molar percentage of the perovskite ABX3); such an amount of amphiphilic molecules can effectively passivate the perovskite crystals.

[0097] Optoelectronic devices

[0098] In a fifth aspect, an embodiment of the present application provides a photoelectric device, comprising a perovskite layer, wherein the perovskite layer comprises the perovskite material provided in the fourth aspect of the embodiment of the present application.

[0099] Because the perovskite layer of the optoelectronic device provided in the embodiment of the present application includes a unique perovskite material, such a perovskite layer has fewer grain boundary defects and good moisture resistance, thereby enabling the optoelectronic device to have excellent photoelectric conversion efficiency and stability.

[0100] In one embodiment, the optoelectronic device includes a solar cell. The solar cell uses the perovskite material unique to the embodiment of the present application, which can better convert light energy into electrical energy, so that the solar cell has good photoelectric conversion efficiency and stability.

[0101] In one embodiment, a photovoltaic device includes a stacked first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode. This structure facilitates the transport of holes and electrons within the device, improving the device's carrier transport performance and thereby further enhancing photoelectric conversion efficiency.

[0102] In some embodiments, as shown in FIG2 , a photovoltaic device includes a stacked first electrode 1, a hole transport layer 2, a perovskite layer 3, an electron transport layer 4, and a second electrode 5. The perovskite layer 3 comprises the perovskite material of the present invention, the perovskite crystal surface of which is modified and passivated with the amphiphilic molecule represented by Formula I. This perovskite material has large grain size and low defect state density, resulting in excellent photoelectric conversion efficiency and stability. This structure also facilitates the transport of holes and electrons within the device, improving the device's carrier transport performance and thus further enhancing photoelectric conversion efficiency.

[0103] In some embodiments, the first electrode 1 can be a transparent conductive substrate, including but not limited to the following materials: fluorine-doped tin oxide (FTO), indium-doped tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium-doped zinc oxide (IZO), etc.

[0104] In some embodiments, the hole transport layer 2 can be at least one of the following materials and their derivatives and materials obtained by doping or passivation: poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), poly-3 hexylthiophene (P3HT), triphenylamine with triptycene as the core (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N- (4-phenylamino) carbazole-spirobifluorene (CzPAF-SBF), poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT:PSS), polythiophene, nickel oxide (NiO x), molybdenum oxide (MoO3), cuprous iodide (CuI), cuprous oxide (CuO), etc.

[0105] In some embodiments, the electron transport layer 4 can be at least one of the following materials and their derivatives and materials obtained by doping or passivation: [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), fullerene C 60 (C 60 ), Fullerene C 70 (C 70 ), tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0106] In some embodiments, the second electrode 5 may be a metal electrode, or one or more conductive oxide electrodes.

[0107] Taking the photoelectric device as a perovskite solar cell as an example, the preparation method includes: providing a first electrode 1, preparing a hole transport layer 2 on the first electrode 1, preparing a perovskite layer 3 on the hole transport layer 2 (specifically, a perovskite film is prepared using the preparation method of an embodiment of the present application), preparing an electron transport layer 4 on the perovskite layer 3, and preparing a second electrode 5 on the electron transport layer 4.

[0108] Electrical devices

[0109] In a sixth aspect, embodiments of the present application further provide an electrical device, comprising the optoelectronic device provided in the fifth aspect of the present application. This optoelectronic device can function as a photoelectric conversion element in the electrical device, converting light energy into electrical energy. Consequently, the electrical device of embodiments of the present application has high photoelectric conversion efficiency and good stability, enabling better operation.

[0110] The electrical devices of the embodiments of the present application may be, but are not limited to, household lighting and power supply. For example, when the photovoltaic device utilized is a solar cell, the electrical device can be installed on a rooftop or in a courtyard to convert solar energy into electricity, thereby providing lighting and power supply for the household. As another example, the electrical device may be a solar power station. For example, solar cells can be used to construct a solar power station, which converts solar energy into electricity and transmits it to the power grid, thereby providing clean energy for the city.

[0111] Example

[0112] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0113] 1. Examples of Amphiphilic Molecules and Their Preparation Methods

[0114] Example A1

[0115] An amphiphilic molecule, as shown in Formula I, wherein n=1, R is a 2-pyridyl group, and X1, X2, X3, X4, and X5 are all fluorine atoms. That is, the amphiphilic molecule is C6F5-CH2CH2-2-pyridine. The preparation method of the amphiphilic molecule is as follows:

[0116] C6F5CH2Br and triethyl phosphite (molar ratio 1:2) were heated at 150°C for 2 hours under nitrogen. The vacuum distilled product was dissolved in dimethylformamide with 1.5 molar equivalents of sodium methoxide and 1 molar equivalent of 2-pyridinecarboxaldehyde. The mixture was stirred at 0°C for 15 minutes and then at room temperature for 90 minutes. Purification, drying, and recrystallization yielded an intermediate containing a double bond. This intermediate was dissolved in ethanol and aerated with nitrogen for 15 minutes. Tris(triphenylphosphine)rhodium chloride (5% by molar weight of the intermediate) was then added. The reaction was maintained at 65°C and 50 psi of hydrogen pressure in a Parr apparatus for 5 hours. After the reaction, the ethanol solvent was evaporated and purified to yield the final product, C6F5-CH2CH2-2-pyridine.

[0117] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1 H NMR δ 8.55 (d, J = 7.2 Hz, 1H), 7.62 (d, J = 7.3 Hz, 1H), 7.53 (m, J = 7.2 Hz, 2H), 3.61 (t, J = 7.4 Hz, 2H), 2.80 (t, J = 7.3 Hz, 2H).

[0118] Example A2

[0119] A biphilic molecule C6F5-CH2CH2-3-pyridine is the same as Example A1 in that R is 3-pyridyl.

[0120] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 11 H NMR δ8.91(s,1H),8.55(d,J=7.2Hz,1H),8.01(d,J=7.2Hz,1H),7.29(m,J=7.4Hz,1H),3.63(t,J=7.4Hz,2H),2.77(t,J=7.3Hz,2H).

[0121] Example A3

[0122] A biphilic molecule C6F5-CH2CH2-4-pyridine is the same as Example A1 in that R is 4-pyridyl.

[0123] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1 H NMR δ 8.41 (d, J = 7.5 Hz, 2H), 7.40 (d, J = 7.3 Hz, 2H), 3.69 (t, J = 7.4 Hz, 2H), 2.89 (t, J = 7.3 Hz, 2H).

[0124] Example A4

[0125] A biphilic molecule C6F5-CH2CH2-2-furan is the same as Example A1 in that R is 2-furyl.

[0126] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1 H NMR δ7.68 (d, J = 7.6 Hz, 1H), 6.73 (d, J = 7.3 Hz, 1H), 6.43 (d, J = 7.2 Hz, 1H), 3.56 (t, J = 7.4 Hz, 2H), 2.85 (t, J = 7.3 Hz, 2H).

[0127] Example A5

[0128] A biphilic molecule C6F5-CH2CH2-3-furan is the same as Example A1 in that R is 3-furyl.

[0129] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1 H NMR δ 8.01 (s, J = 7.2 Hz, 1H), 7.05 (d, J = 7.3 Hz, 1H), 6.61 (d, J = 7.3 Hz, 1H), 3.63 (t, J = 7.4 Hz, 2H), 2.77 (t, J = 7.3 Hz, 2H).

[0130] Example A6

[0131] A biphilic molecule C6F5-CH2CH2-2-thiophene is the same as Example A1 in that R is a 2-thienyl group.

[0132] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1H NMR δ 7.49 (t, J = 7.7 Hz, 1H), 7.29 (m, J = 7.3 Hz, 1H), 7.00 (t, J = 7.5 Hz, 1H), 3.60 (t, J = 7.4 Hz, 2H), 2.81 (t, J = 7.3 Hz, 2H).

[0133] Example A7

[0134] A biphilic molecule C6F5-CH2CH2-3-thiophene is the same as Example A1 in that R is 3-thienyl.

[0135] The resulting amphiphilic product is 1 Characterization by H NMR (DMSO-d6, 300 MHz). 1 H NMR δ 7.57 (t, J = 7.6 Hz, 1H), 7.51 (s, J = 7.3 Hz, 1H), 7.02 (d, J = 7.5 Hz, 1H), 3.51 (t, J = 7.4 Hz, 2H), 2.78 (t, J = 7.3 Hz, 2H).

[0136] 2. Perovskite Solar Cell Example

[0137] Example B1

[0138] A perovskite solar cell includes a stacked ITO substrate, a hole transport layer, a perovskite layer, an electron transport layer, and a copper electrode. The preparation steps are as follows:

[0139] Step 1: Take an ITO conductive glass with a specification of 2.0*2.0cm, remove 0.35cm of ITO at each end by laser etching, and expose the glass substrate; ultrasonically clean the etched ITO conductive glass several times with water, acetone, and isopropyl alcohol in sequence; blow the ITO conductive glass dry with a nitrogen gun, and further clean it in a UV ozone machine to obtain an ITO substrate after UV ozone treatment;

[0140] Step 2: Spin-coat 2 mg / mL of poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) on the UV-ozone treated ITO substrate at a rate of 5000 rpm / s and anneal on a hot plate at 100°C for 10 minutes to obtain a hole transport layer with a thickness of 40 nm.

[0141] Step 3: Prepare a MAPbI3 precursor solution with a concentration of 1.4M, then add the amphiphilic molecules in Example A1 (the amount added is 0.05 mol% of MAPbI3), stir evenly, spin coat on the hole transport layer at 3000 rpm / s, anneal at 100°C for 30 minutes, and cool to room temperature to obtain a MAPbI3 perovskite layer passivated by the amphiphilic molecules with a thickness of 650 nm.

[0142] Step 4: Phenyl-C61-butyric acid methyl ester (PCBM) was spin-coated on the perovskite layer at 1000 rpm / s, annealed at 100°C for 10 minutes, and then a passivation layer of bathocuproine (BCP) was spin-coated at 5000 rpm / s to form an electron transport layer. The thickness of the PCBM layer was 30 nm, and the thickness of the BCP layer was 10 nm.

[0143] Step 5: Place the wafer obtained in step 4 into a vapor deposition machine and vapor deposit a copper electrode to 80 nm at a rate of 1 A / s to complete the overall device preparation.

[0144] Example B2

[0145] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A2 is added to the precursor solution during the preparation of the perovskite layer.

[0146] Example B3

[0147] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A3 is added to the precursor solution during the preparation of the perovskite layer.

[0148] Example B4

[0149] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A4 is added to the precursor solution during the preparation of the perovskite layer.

[0150] Example B5

[0151] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A5 is added to the precursor solution during the preparation of the perovskite layer.

[0152] Example B6

[0153] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A6 is added to the precursor solution during the preparation of the perovskite layer.

[0154] Example B7

[0155] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule of Example A7 is added to the precursor solution during the preparation of the perovskite layer.

[0156] Example B8

[0157] A perovskite solar cell is the same as Example B7 except that the amount of the amphiphilic molecule in Example A7 added to the precursor solution during the preparation of the perovskite layer is 0.01 mol%.

[0158] Example B9

[0159] A perovskite solar cell is the same as Example B7 except that the amount of the amphiphilic molecule in Example A7 added to the precursor solution during the preparation of the perovskite layer is 0.2 mol%.

[0160] Comparative Example 1

[0161] A solar cell is the same as Example B1 except that no amphiphilic molecules are added during the preparation of the perovskite layer.

[0162] Comparative Example 2

[0163] A solar cell is the same as Example B1 except that 1-benzyl-3-hydroxypyridinium chloride is used to replace the amphiphilic molecule in Example A1 during the preparation of the perovskite layer.

[0164] Performance Testing

[0165] Under standard simulated sunlight (AM 1.5G, 100mW / cm 2 ) under continuous illumination to test the efficiency of the perovskite solar cell and its light stability. The effective area of ​​the test device is 0.08 cm 2 .

[0166] a. Photovoltaic conversion efficiency test of perovskite solar cells:

[0167] Under standard simulated sunlight (AM 1.5G, 100mW / cm 2 ) irradiation, the solar cell is tested to obtain the IV curve. According to the IV curve and the data fed back by the test equipment, the short-circuit current Jsc (unit: mA / cm 2 ), open-circuit voltage Voc (V), maximum optical output current Jmpp (mA), and maximum optical output voltage Vmpp (V). The cell's fill factor (FF) (in %) is calculated using the formula FF = (Jmpp × Vmpp) / Jsc × Voc. The cell's photoelectric conversion efficiency (PCE) (in %) is calculated using the formula PCE = Jsc × Voc × FF / Pw, where Pw represents the input power (in mW).

[0168] b. Perovskite solar cell stability test:

[0169] The prepared solar cell device was placed in a dry room at 65°C hot plate for accelerated testing with a humidity of about 5%. The device efficiency was retested after 10 days, and the ratio of the efficiency after 10 days to the initial efficiency was calculated.

[0170] The specific experimental results are shown in Table 1.

[0171] Table 1

[0172] It can be seen from the test results in Table 1 that the perovskite layer of the perovskite solar cell is passivated using the amphiphilic molecules unique to the embodiments of the present application. Therefore, the embodiments of the present application not only have better light conversion efficiency than the comparative example, but also the efficiency stability of the solar cell device of the embodiments of the present application is better; and the passivation effect is better when the amount of amphiphilic molecules is appropriately increased.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An amphiphilic molecule, wherein The general chemical structure of the amphiphilic molecule is shown in Formula I: Wherein, R includes a Lewis basic group, X1, X2, X3, X4, and X5 independently include at least one of hydrogen and halogen atoms, and X1, X2, X3, X4, and X5 are not hydrogen at the same time, and n is an integer greater than or equal to 1.

2. The amphiphilic molecule according to claim 1, wherein n is 1 to 9.

3. The amphiphilic molecule according to claim 1 or 2, wherein The Lewis basic group includes at least one of a thienyl group, a furyl group, a pyridyl group and a 3-methylimidazolyl group.

4. The amphiphilic molecule according to any one of claims 1 to 3, wherein X1, X2, X3, X4, and X5 are the same halogen atoms.

5. The amphiphilic molecule according to any one of claims 1 to 4, wherein The amphiphilic molecules include:

6. A method for preparing an amphiphilic molecule, wherein: The steps include: The compound represented by formula II is subjected to hydrogenation reaction to obtain the amphiphilic molecule as claimed in any one of claims 1 to 5; 7. The preparation method according to claim 6, wherein The temperature of the hydrogenation reaction is 60-80° C.; and / or, The hydrogenation reaction time is 2 to 8 hours.

8. The preparation method according to claim 6 or 7, wherein: The hydrogenation reaction is carried out under rhodium catalyst conditions; and / or, The hydrogenation reaction is carried out in an alcohol solvent.

9. The preparation method according to any one of claims 6 to 8, wherein: The synthesis steps of the compound shown in formula II include: subjecting the compound shown in formula III to a nucleophilic substitution reaction with triethyl phosphite, and then reacting the product of the nucleophilic substitution reaction with R-(CH2) n-1 -CO undergoes addition reaction; Wherein, X' is a halogen atom.

10. Use of the amphiphilic molecule according to any one of claims 1 to 5 and / or the amphiphilic molecule prepared by the preparation method according to any one of claims 6 to 9 as a perovskite crystal passivator.

11. A perovskite material, wherein: The perovskite material comprises a perovskite crystal and the amphiphilic molecule according to any one of claims 1 to 5 and / or the amphiphilic molecule prepared by the preparation method according to any one of claims 6 to 9 combined with the perovskite.

12. The perovskite material according to claim 11, wherein: The molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.002).

13. A photoelectric device comprising a perovskite layer, wherein the perovskite layer comprises the perovskite material according to claim 11 or 12.

14. The optoelectronic device according to claim 13, wherein: The photovoltaic device includes a solar cell.

15. An electrical device, wherein: The electrical device comprises the optoelectronic device according to claim 13 or 14.

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