Amphiphilic molecule, preparation method therefor and use thereof

Abstract

The present application discloses an amphiphilic molecule, a preparation method therefor and a use thereof. The chemical structural general formula of the amphiphilic molecule provided by the present application is shown as formula I: wherein R comprises a Lewis base group, X comprises at least one of a hydrogen atom and a halogen atom, and n is an integer greater than or equal to 0. The amphiphilic molecule of the present application has both a Lewis acid group and a Lewis base group, such that the amphiphilic molecule can be used for passivating two defects of perovskite grain boundaries, namely, under-coordinated anions and under-coordinated cations, and therefore, use of such an amphiphilic molecule in a perovskite material can significantly improve the conversion efficiency and stability of perovskite.

Description

Amphiphilic molecules and their preparation methods and applications

[0001] This application claims priority to Chinese patent application No. 202310712849.0 filed with the Patent Office of China on June 15, 2023, entitled “Amphiphilic molecules, preparation methods and applications thereof”, the entire contents of which are incorporated herein by reference. 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 base group, X includes at least one of a hydrogen atom and a halogen atom, and n is an integer greater than or equal to 0.

[0009] Utilize amphiphilic molecules to have Lewis acid (Lewis Acid, LA) group and Lewis base (Lewis Base, LB) group simultaneously, specifically, R includes Lewis base group, and fullerene is Lewis acid group, such amphiphilic molecules can be used for passivating two kinds of defects of perovskite grain boundary, namely under-coordinated anion and under-coordinated cation, on the one hand, fullerene can receive the electron of anion at perovskite crystal edge as Lewis acid group to passivate under-coordinated anion of perovskite crystal, on the other hand, the lone electron pair of Lewis base at R end can provide under-coordinated cation to passivate perovskite crystal anion vacancy defect. R group and fullerene are connected by pyrazole ring structure, and the large steric effect of benzene ring connected based on pyrazole ring structure can make amphiphilic molecules stably bonded to perovskite crystal surface, while increasing the crystal grain of perovskite, and can improve the moisture resistance of perovskite based on the hydrophobicity of the amphiphilic molecules themselves. Therefore, the present application embodiment provides that amphiphilic molecules can better passivate the surface defects of perovskite crystal, thereby improving the conversion efficiency and stability of perovskite.

[0010] In one embodiment, the Lewis base group includes at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group.

[0011] 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.

[0012] In one embodiment, the fullerene in Formula I comprises fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 At least one of .

[0013] The above-mentioned fullerenes can act as Lewis acid groups to bind to under-coordinated anions and passivate the under-coordinated anions in the perovskite crystal by accepting electrons from the anions at the edge of the perovskite crystal.

[0014] In one embodiment, n=0-10.

[0015] Such a carbon chain can connect the R group in formula I and the fullerene, and depending on the specific defect types of the perovskite grain boundary, the amphiphilic molecule can flexibly combine with undercoordinated anions and undercoordinated cations as needed.

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

[0017] Fullerene C is the most common amphiphilic molecule 60As a Lewis acid group, not only is the structure stable and can effectively passivate perovskite grain boundary defects, but the above-mentioned amphiphilic molecules are 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 an addition reaction with fullerene to obtain the amphiphilic molecule provided in the first aspect of the embodiment of the present application;

[0020] Wherein, X' is a halogen atom.

[0021] The amphiphilic molecule of Formula I in the examples of this application can be obtained by using the compound of Formula II and fullerene as synthetic raw materials and performing an addition reaction between the two. This preparation method is not only simple and easy to implement, but also the amphiphilic molecule with 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.

[0022] In one embodiment, the temperature of the addition reaction is 70-90° C.; and / or

[0023] The addition reaction time is 2 to 8 hours.

[0024] The temperature and time of the above addition reaction can well achieve the synthesis of amphiphilic molecules.

[0025] In one embodiment, the addition reaction is carried out in the presence of triethylamine as a catalyst; and / or,

[0026] The addition reaction is carried out in a benzene solvent.

[0027] The addition of the above catalysts can greatly improve the synthesis efficiency of amphiphilic molecules, while benzene solvents can provide a good environment for the synthesis of amphiphilic molecules.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.001).

[0033] The amphiphilic molecules at the above ratio can passivate the perovskite crystals well.

[0034] 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.

[0035] 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.

[0036] In one embodiment, the optoelectronic device includes a stacked first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode; wherein the material of the electron transport layer includes at least one of fullerene, phenyl-C71-butyric acid methyl ester, and phenyl-C61-butyric acid methyl ester.

[0037] The optoelectronic device with this structure is conducive to the transport of holes and electrons in the device, which can improve the carrier transport performance of the device. At the same time, the amphiphilic molecules in the perovskite layer can match well with the material of the electron transport layer, which is conducive to the current extraction of the optoelectronic device, thereby further improving the photoelectric conversion efficiency.

[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 the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present 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 base group, X includes at least one of a hydrogen atom and a halogen atom, and n is an integer greater than or equal to 0.

[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 molecules shown in the above formula I provided in the embodiments of the present application have both Lewis acid groups and Lewis base groups. Specifically, R includes a Lewis base group that can donate electron pairs, while fullerene, as a Lewis acid group, can accept electron pairs. The amphiphilic molecules 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) fullerene, 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 donated to the undercoordinated cation to passivate the anion vacancy defect in the perovskite crystal.

[0064] In the amphiphilic molecule shown in the above formula I provided in the embodiments of the present application, the R group and the fullerene are connected by a pyrazole ring structure, and the nitrogen atom in the pyrazole ring structure is also connected to a benzene ring structure. Based on the large steric effect of the benzene ring connected to the pyrazole ring structure, not only can the orientation of the product molecule be determined during the synthesis of the amphiphilic molecule, but also the amphiphilic molecule can be stably bound to the surface of the perovskite crystal, while increasing the grain size of the perovskite. The hydrophobicity of the amphiphilic molecule itself can improve the moisture resistance of the perovskite. Therefore, the amphiphilic molecule provided in the embodiments of the present application can better passivate 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 represented by Formula I, This means that two adjacent carbon atoms of the fullerene are connected to the pyrazole ring structure. Specifically, the fullerene and the pyrazole ring structure share two adjacent carbon atoms. This makes the fullerene connection more stable.

[0066] 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.

[0067] 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.

[0068] In one embodiment, in the amphiphilic molecule represented by formula I, the fullerene comprises fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 At least one of .

[0069] Fullerene is a hollow molecule composed entirely of carbon and can be spherical, ellipsoidal, cylindrical or tubular in shape. Fullerene contains not only six-membered rings but also five-membered rings and occasionally seven-membered rings. According to the total number of carbon atoms, fullerene can be divided into C 20 、C 60 、C 70 、C 76 、C 80 The present invention discloses a zwitterionic molecule containing the aforementioned fullerenes for use in perovskites. The fullerenes, as Lewis acid groups, can bind to under-coordinated anions and passivate the under-coordinated anions in the perovskite crystal by accepting electrons from the anions at the edge of the perovskite crystal.

[0070] In one embodiment, in the amphiphilic molecule represented by Formula I, n = 0 to 10. For example, n can be 1, 2, 4, 5, 6, 8, 10, etc. n represents the number of -CH2- groups connecting the R group to the pyrazole ring structure.

[0071] Specifically, n=0-10. In the amphiphilic molecule shown in Formula I, the R group and the fullerene are connected through 1-10 -CH2- groups. The distance between the R group and the fullerene is short, and it is not easy to form an intermolecular adduct. Therefore, according to the specific defect type of the perovskite grain boundary, the amphiphilic molecule can flexibly combine with under-coordinated anions and under-coordinated cations as needed.

[0072] In one embodiment, in the amphiphilic molecule represented by Formula I, X can be a hydrogen or halogen atom. Specifically, one end of the pyrazole ring structure connecting the R group to the fullerene can be connected to benzene or a halogen-substituted benzene, specifically ortho-, meta-, or para-substituted. The substituted halogen atom can be fluorine, chlorine, bromine, iodine, or the like.

[0073] In one embodiment, the amphiphilic molecule comprises the following structure:

[0074] Fullerene C is the most common amphiphilic molecule 60As a Lewis acid group, it is not only structurally stable and can effectively passivate perovskite grain boundary defects, but also the X-para-substituted amphiphilic molecules are easy to synthesize.

[0075] Preparation method of amphiphilic molecules

[0076] In a second aspect, the present invention provides a method for preparing an amphiphilic molecule, comprising the following steps:

[0077] The compound represented by formula II is subjected to an addition reaction with fullerene to obtain the amphiphilic molecule provided in the first aspect of the embodiment of the present application;

[0078] Wherein, X' is a halogen atom.

[0079] The compound represented by Formula II and fullerene are used as raw materials for synthesizing amphiphilic molecules. These are subjected to an addition reaction, whereby X' in the compound represented by Formula II and the nitrogen atom connecting the benzene ring structure react with two adjacent carbon atoms of the fullerene to form a pyrazole ring structure, thereby obtaining 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 also the resulting amphiphilic molecule, based on Lewis acid and Lewis base groups, can effectively passivate surface defects in perovskite crystals, thereby improving the conversion efficiency and stability of the perovskite.

[0080] In one embodiment, the raw material fullerene can be fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 X, R and n in the compound of formula II correspond to X, R and n in the amphiphilic molecule of formula I.

[0081] In one embodiment, the temperature of the addition reaction is 70-90° C. (Celsius); illustratively, the temperature of the addition reaction can be 70° C., 75° C., 80° C., 85° C., 90° C., etc. The addition reaction can be well promoted at a temperature of 70-90° C.

[0082] In one embodiment, the addition 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. By performing the addition reaction for 2 to 8 hours, the synthesis of the amphiphilic molecule can be fully achieved.

[0083] In one embodiment, the addition reaction temperature is 70-90° C., and the addition reaction time is 2-8 hours. Under the above addition reaction temperature and time conditions, the compound represented by Formula II and the fullerene undergo sufficient addition reaction to efficiently synthesize the amphiphilic molecule.

[0084] In one embodiment, the addition reaction is carried out in the presence of triethylamine catalyst. The addition of triethylamine catalyst can increase the addition reaction rate, thereby greatly improving the synthesis efficiency of the amphiphilic molecule shown in the product formula I.

[0085] In one embodiment, the amount of triethylamine catalyst added may be 1-10% of the total amount of fullerenes.

[0086] In one embodiment, the addition reaction can be carried out in a benzene-based solvent. Specifically, the benzene-based solvent can include benzene or chlorobenzene. According to the principle of like dissolves like, the benzene-based solvent and the raw materials, i.e., the compound shown in II and the fullerene, all have benzene ring structures. Therefore, this type of solvent can fully dissolve the raw materials for the addition reaction.

[0087] In one embodiment, X, R, and n in the compound of formula II correspond to X, R, and n in the amphiphilic molecule of formula I. The compound of formula II can be synthesized in a variety of ways depending on the choice of X' and X.

[0088] Taking the compound represented by the raw material formula II as an example, X' is a chlorine atom, and X is a para-substituted chlorine atom. The steps of the synthesis method of the compound represented by the formula II may include: reacting the raw material with a formaldehyde reagent containing an R group, such as R-(CH2) n -CHO is mixed with phenylhydrazine and reacted in dry dimethylformamide (DMF), and then the product is subjected to a chlorination reaction. Specifically, N-chlorosuccinimide (NCS) is added to the reaction system and stirred to carry out the chlorination reaction. Finally, the solvent in the mixed solution after the chlorination reaction is completed is removed, and the residual solid is purified by silica gel column chromatography to obtain the target product. In this process, phenylhydrazine is selected to utilize the large steric effect of the benzene ring to determine the molecular orientation of the product, and the chlorination reaction of NCS can form a chlorine atom at the X' position, preparing for the subsequent addition with fullerene to form a pyrazole ring structure. The specific process is as follows:

[0089] application

[0090] 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.

[0091] 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.

[0092] Specifically, the types and preparation methods of the amphiphilic molecules represented by Formula I are described above.

[0093] Perovskite materials

[0094] 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.

[0095] 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.

[0096] 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 + 、CH(NH2)2 + 、Cs + 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 .

[0097] 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.

[0098] 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.

[0099] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.001). 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, etc. The amphiphilic molecule in the above molar ratio can effectively passivate the perovskite crystal.

[0100] 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.

[0101] In the above process, the amount of the amphiphilic molecules added to the perovskite precursor solution can be 0.01 mol% to 0.1 mol% (as a percentage of the molar ratio of the perovskite ABX3); such an amount of amphiphilic molecules can well passivate the perovskite crystals.

[0102] Optoelectronic devices

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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. The electron transport layer is made of at least one of fullerene, phenyl-C71-butyric acid methyl ester, and phenyl-C61-butyric acid methyl ester. This structure facilitates the transport of holes and electrons within the device, improving the device's carrier transport performance. Furthermore, the amphiphilic molecules in the perovskite layer are well matched with the material of the electron transport layer, facilitating current extraction from the photovoltaic device and further enhancing photoelectric conversion efficiency.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] Furthermore, the material of electron transport layer 4 includes at least one of fullerene, phenyl-C71-butyric acid methyl ester, and phenyl-C61-butyric acid methyl ester. The amphiphilic molecules in perovskite layer 3 can be well matched with the fullerene, phenyl-C61-butyric acid methyl ester, or phenyl-C71-butyric acid methyl ester in electron transport layer 4, facilitating current extraction from the photovoltaic device, thereby further improving photoelectric conversion efficiency.

[0112] In some embodiments, the second electrode 5 may be a metal electrode, or one or more conductive oxide electrodes.

[0113] 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.

[0114] Electrical devices

[0115] 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.

[0116] 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.

[0117] Example

[0118] 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.

[0119] 1. Examples of Amphiphilic Molecules and Their Preparation Methods

[0120] Example A1

[0121] An amphiphilic molecule, as shown in formula I, wherein n=0, R is a 2-pyridyl group, X is a para-substituted chlorine atom, and fullerene is C 60 The preparation method of the amphiphilic molecule is as follows:

[0122] The raw materials 2-pyridinecarboxaldehyde and phenylhydrazine are mixed in equal amounts in dimethylformamide (DMF) solvent and stirred to react. Then two equivalents of N-chlorosuccinimide (NCS) are added to the reaction system, and the solution of the reaction system is stirred to carry out chlorination reaction. Finally, the solvent is removed and the residual solid is purified by silica gel column chromatography. The obtained product is the same as fullerene C 60 (2:1 molar ratio) and fullerene C 60 A molar amount of 1% triethylamine was added to chlorobenzene solvent and heated at 80°C for 5 hours under nitrogen atmosphere. After cooling to room temperature, the solvent was removed under reduced pressure and the product was purified by silica gel column chromatography to obtain an amphoteric molecule.

[0123] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1H NMR δ 8.71 (d, J = 7.2 Hz, 1H), 7.96 (d, J = 7.3 Hz, 1H), 7.75 (m, J = 7.2 Hz, 2H), 7.60 (d, J = 7.4 Hz, 2H), 7.44 (d, J = 7.3 Hz, 2H).

[0124] Example A2

[0125] A amphiphilic molecule, the main difference from Example A1 is that R is 3-pyridyl, and all other aspects are the same.

[0126] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ9.07 (s, 1H), 8.75 (d, J = 7.2Hz, 1H), 8.30 (d, J = 7.2Hz, 1H), 7.58 (m, J = 7.4Hz, 1H), 7.60 (d, J = 7.4Hz, 2H), 7.45 (d, J = 7.3Hz, 2H).

[0127] Example A3

[0128] A amphiphilic molecule, which is the same as Example A1 mainly in that R is 4-pyridyl.

[0129] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ 8.69 (d, J = 7.5 Hz, 2H), 7.51 (d, J = 7.3 Hz, 2H), 7.60 (d, J = 7.4 Hz, 2H), 7.44 (d, J = 7.3 Hz, 2H).

[0130] Example A4

[0131] A amphiphilic molecule, which is the same as Example A1 mainly in that R is 2-furyl.

[0132] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ 7.78 (d, J = 7.6 Hz, 1H), 6.93 (d, J = 7.3 Hz, 1H), 6.60 (d, J = 7.2 Hz, 1H), 7.60 (d, J = 7.4 Hz, 2H), 7.43 (d, J = 7.3 Hz, 2H).

[0133] Example A5

[0134] A amphiphilic molecule, the main difference from Example A1 is that R is 3-furyl, and all other aspects are the same.

[0135] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ 8.15 (s, J = 7.2 Hz, 1H), 7.25 (d, J = 7.3 Hz, 1H), 6.80 (d, J = 7.3 Hz, 1H), 7.59 (d, J = 7.4 Hz, 2H), 7.44 (d, J = 7.3 Hz, 2H).

[0136] Example A6

[0137] A amphiphilic molecule, the main difference from Example A1 is that R is 2-thienyl, and all other aspects are the same.

[0138] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ 7.57 (t, J = 7.7 Hz, 1H), 7.49 (m, J = 7.3 Hz, 1H), 7.10 (t, J = 7.5 Hz, 1H), 7.58 (d, J = 7.4 Hz, 2H), 7.44 (d, J = 7.3 Hz, 2H).

[0139] Example A7

[0140] A amphiphilic molecule, the main difference from Example A1 is that R is 3-thienyl, and all other aspects are the same.

[0141] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H NMR δ 7.73 (t, J = 7.6 Hz, 1H), 7.67 (s, J = 7.3 Hz, 1H), 7.22 (d, J = 7.5 Hz, 1H), 7.59 (d, J = 7.4 Hz, 2H), 7.44 (d, J = 7.3 Hz, 2H).

[0142] 2. Perovskite Solar Cell Example

[0143] Example B1

[0144] 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:

[0145] 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;

[0146] 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.

[0147] 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.

[0148] 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.

[0149] Step 5: Place the wafer obtained in step 4 into an evaporation machine and evaporate a copper electrode to 80 nm at a rate of 1 A / s to complete the preparation of the entire device.

[0150] Example B2

[0151] 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.

[0152] Example B3

[0153] 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.

[0154] Example B4

[0155] 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.

[0156] Example B5

[0157] 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.

[0158] Example B6

[0159] 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.

[0160] Example B7

[0161] 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.

[0162] Example B8

[0163] 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%.

[0164] Example B9

[0165] 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 0.1 mol%.

[0166] Example B10

[0167] A perovskite solar cell is the same as Example B7 except that the electron transport layer material is zinc oxide.

[0168] Comparative Example 1

[0169] A solar cell is the same as Example B1 except that no amphiphilic molecules are added during the preparation of the perovskite layer.

[0170] Comparative Example 2

[0171] 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.

[0172] Performance Testing

[0173] 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 .

[0174] a. Photovoltaic conversion efficiency test of perovskite solar cells:

[0175] 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).

[0176] b. Perovskite solar cell stability test:

[0177] 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.

[0178] The specific experimental results of the above tests are shown in Table 1.

[0179] Table 1

[0180] 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 by appropriately increasing the amount of the amphiphilic molecules, the passivation effect is better, and the effect is better when combined with the electron transport layer material fullerene or phenyl-C61-butyric acid methyl ester.

[0181] 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 chemical structure of the amphiphilic molecule is shown in Formula I: Wherein, R includes a Lewis base group, X includes at least one of a hydrogen atom and a halogen atom, and n is an integer greater than or equal to 0.

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

3. The amphiphilic molecule according to claim 1 or 2, wherein The fullerenes in formula I include fullerene C 20 , Fullerene C 60 , Fullerene C 70 , Fullerene C 76 and fullerene C 80 At least one of .

4. The amphiphilic molecule according to any one of claims 1 to 3, wherein n＝0～10。 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 addition reaction with fullerene to obtain the amphiphilic molecule as claimed in any one of claims 1 to 5; Wherein, X' is a halogen atom.

7. The preparation method according to claim 6, wherein The temperature of the addition reaction is 70-90° C.; and / or The addition reaction time is 2 to 8 hours.

8. The preparation method according to claim 6 or 7, wherein: The addition reaction is carried out under triethylamine catalyst conditions; and / or, The addition reaction is carried out in a benzene solvent.

9. 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 8 as a perovskite crystal passivator.

10. 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 8, which is combined with the perovskite crystal.

11. The perovskite material according to claim 10, wherein: The molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.001).

12. A photoelectric device comprising a perovskite layer, wherein the perovskite layer comprises the perovskite material according to claim 10 or 11.

13. The optoelectronic device according to claim 12, wherein: The photoelectric device includes a stacked first electrode, a hole transport layer, a perovskite layer, an electron transport layer and a second electrode; wherein the material of the electron transport layer includes at least one of fullerene, phenyl-C71-butyric acid methyl ester and phenyl-C61-butyric acid methyl ester.

14. The optoelectronic device according to claim 12 or 13, wherein: The photovoltaic device includes a solar cell.

15. An electrical device, wherein: The electrical device comprises the optoelectronic device according to any one of claims 12-14.

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