Amplitude molecule as well as preparation method and application thereof

Abstract

The invention discloses an amphiphilic molecule as well as a preparation method and application thereof. The general formula of the chemical structure of the amphiphilic molecule provided by the invention is as shown in formula I: # imgabs0 #, 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 amphiphilic molecule provided by the invention has a Lewis acid group and a Lewis base group at the same time, so that the amphiphilic molecule can be used for passivating two defects of perovskite crystal boundaries, namely anions with insufficient coordination and cations with insufficient coordination; therefore, when the amphiphilic molecule is used in a perovskite material, the conversion efficiency and the stability of perovskite can be remarkably improved.

Description

Technical Field

[0001] The present application belongs to the field of perovskite technology, and specifically relates to a amphiphilic molecule and a preparation method and application thereof. Background Art

[0002] Perovskite materials are a type of semiconductor nanomaterials with uniform size and high color purity. Their elemental composition has a crystal structure similar to that of the mineral CaTiO3. Perovskite materials have strong light absorption capacity and a wide absorption range, and have great advantages in the field of optoelectronics. For example, perovskite solar cells (PSCs) with organic-inorganic hybrid perovskite materials as light-absorbing layers are developing rapidly.

[0003] In an ideal perovskite crystal structure, each atom has its own corresponding position, but actual perovskites produce surface defects due to the influence of crystal growth and post-processing. The grain boundary defect states formed in perovskite crystals easily lead to non-radiative recombination of carriers, thus affecting its photoelectric conversion efficiency. Summary of the invention

[0004] In view of the above problems, the present application provides a amphiphilic molecule and a preparation method and application thereof, aiming to solve the technical problem of how to reduce perovskite grain boundary defects.

[0005] In a first aspect, the present invention provides an amphiphilic molecule, and the general chemical structure of the amphiphilic molecule is shown in Formula I:

[0006]

[0007] 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.

[0008] The amphiphilic molecule has both Lewis acid (LA) group and Lewis base (LB) group. Specifically, in the amphiphilic molecule shown in Formula I, R includes Lewis base group, and the halogen-substituted benzene ring structure is Lewis acid group. Such amphiphilic molecule can be used to passivate two defects of perovskite crystal boundary, namely insufficiently coordinated anion and insufficiently coordinated cation. On the one hand, the halogen-substituted benzene ring structure can receive the electrons of the anion at the edge of the perovskite crystal as a Lewis acid group to passivate the insufficiently coordinated anion 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 cation to passivate the anion vacancy defect of the perovskite crystal; and, based on the hydrophobicity of the amphiphilic molecule itself, the moisture resistance of the perovskite can be improved. Therefore, the embodiment of the present application provides that the amphiphilic molecule can better passivate the surface defects of the perovskite crystal, thereby improving the conversion efficiency and stability of the perovskite.

[0009] In one embodiment, n is 1-9.

[0010] 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.

[0011] 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.

[0012] The above-mentioned Lewis base groups can bind to under-coordinated cations and provide them with lone electron pairs to passivate anion vacancy defects in perovskite crystals.

[0013] In one embodiment, X1, X2, X3, X4, and X5 are the same halogen atoms.

[0014] The fully halogenated benzene ring structure, as a Lewis acid group, can better combine with under-coordinated anions to better passivate under-coordinated anions in perovskite crystals.

[0015] In one embodiment, the amphiphilic molecule comprises:

[0016]

[0017] The fully fluorinated benzene rings in the amphiphilic molecules serve as Lewis acid groups, which are not only structurally stable and can effectively passivate perovskite grain boundary defects, but 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 a hydrogenation reaction to obtain the amphiphilic molecule provided by the first aspect of the embodiment of the present application;

[0020]

[0021] The compound shown in Formula II is subjected to hydrogenation reaction to obtain the amphiphilic molecule shown in Formula I in the embodiment of the present application. The preparation method is not only simple in process and easy to implement, but also the amphiphilic molecule having Lewis acid group and Lewis base group can passivate the grain boundary defects of perovskite well, thereby improving the conversion efficiency and stability of perovskite.

[0022] In one embodiment, the temperature of the hydrogenation reaction is 60-80° C.; and / or,

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

[0024] The synthesis of amphiphilic molecules can be well achieved under the above temperature and time conditions.

[0025] In one embodiment, the hydrogenation reaction is carried out under rhodium catalyst conditions; and / or,

[0026] The hydrogenation reaction is carried out in an alcohol solvent.

[0027] The addition of the above catalyst can greatly improve the synthesis efficiency of the amphiphilic molecules, and the alcohol solvent can provide a good environment for the synthesis of the amphiphilic molecules.

[0028] 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;

[0029]

[0030] Wherein, X' is a halogen atom.

[0031] Triethyl phosphite first undergoes a nucleophilic substitution reaction with the halogenated benzene ring hydrocarbon shown in formula III, and then reacts with the aldehyde to obtain a HWE (Horner-Wadsworth-Emmons) reaction product, namely, the compound shown in formula II.

[0032] 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.

[0033] The amphiphilic molecule shown in Formula I has both Lewis acid groups and Lewis base groups, and can be used to passivate anions and cations with insufficient coordination 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.

[0034] In a fourth aspect, an embodiment of the present application provides a perovskite material, the perovskite material comprising a perovskite crystal and an amphiphilic molecule provided in the first aspect of the embodiment of the present application combined with the perovskite crystal and / or an amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiment of the present application.

[0035] Because the 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.

[0036] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.002).

[0037] The amphiphilic molecules in the above ratio can passivate the perovskite crystals well.

[0038] 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.

[0039] 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, so that the optoelectronic device has good photoelectric conversion efficiency and stability.

[0040] In one embodiment, the optoelectronic device comprises a solar cell.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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

[0045] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0046] Figure 1 : is a schematic diagram comparing the perovskite of the embodiment of the present application before and after passivation by the amphiphilic molecule;

[0047] Figure 2 is a schematic structural diagram of a solar cell according to an embodiment of the present application;

[0048] Description of reference numerals:

[0049] 1-first electrode, 2-hole transport layer, 3-perovskite layer, 4-electron transport layer, 5-second electrode. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces). "At least one" refers to more than one (including one, two, three, etc.).

[0056] 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0057] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0058] As traditional energy resources are increasingly scarce, the development of new energy sources has received increasing attention. Due to the new demand for green energy in modern society, optoelectronic devices such as solar cells that convert light energy into electrical energy through the photoelectric effect have developed rapidly. At present, solar cells have developed to the third generation, namely perovskite solar cells (PSCs). Perovskite solar cells have the advantages of high photoelectric conversion efficiency and low power generation cost, and have the potential to be integrated with buildings. They are expected to become a substitute for curtain wall decoration of high-rise buildings, thereby achieving lighting and power generation at the same time.

[0059] Perovskite solar cells are solar cells that use perovskite-type organic metal halide semiconductors as light-absorbing materials. Perovskite, as a synthetic material, has become popular since it was applied to the field of photovoltaic power generation due to its excellent performance, low cost and huge commercial value. The quality of the perovskite layer, as the light-absorbing layer in perovskite solar cells, directly affects the conversion efficiency and stability of the device.

[0060] Perovskite is susceptible to surface defects due to the influence of crystal growth and its post-processing. For example, there are two main 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, thus 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-coordinated divalent cations (such as Pb) on the perovskite surface as Lewis acids. 2+ ), generating Lewis adducts, but they cannot passivate under-coordinated halide ions, thus improving the performance of solar cells to a limited extent.

[0061] Based on the above considerations, in order to simultaneously overcome the various defects of the current perovskite, the present embodiment designs a amphiphilic molecule having both a Lewis acid group and a Lewis base group, which can simultaneously passivate the above two types of defects of the perovskite, thereby further improving the performance of the perovskite. The following technical solution is proposed.

[0062] Amphiphilic molecules

[0063] In a first aspect, the present invention provides an amphiphilic molecule, and the general chemical structure of the amphiphilic molecule is shown in Formula I:

[0064]

[0065] 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.

[0066] According to the Lewis acids and bases theory, also known as the acid-base electronic theory: any substance (molecule, ion or atom group) that can accept an electron pair is called a Lewis acid (LA), and any substance (molecule, ion or atom 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.

[0067] The amphiphilic molecule shown in the above formula I provided in the embodiment of the present application has both a Lewis acid group and a Lewis base group. Specifically, R includes a Lewis base group that can give an electron pair, and the halogen-substituted benzene ring structure as a Lewis acid group can accept an electron pair. The amphiphilic molecule provided in the embodiment of the present application can be used to passivate two defects at the perovskite crystal boundary, namely, insufficiently coordinated anions and insufficiently coordinated cations. Specifically: (1) the halogen-substituted benzene ring structure as a Lewis acid group can receive electrons from anions at the edge of the perovskite crystal to passivate the insufficiently coordinated anions of the perovskite crystal, and (2) the lone electron pair of the Lewis base at the R end can be provided to the insufficiently coordinated cation to passivate the anion vacancy defect of the perovskite crystal.

[0068] 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 an intermolecular adduct. 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.

[0069] In one embodiment, in the amphiphilic molecule shown in Formula I, the Lewis base group in R includes at least one of thienyl, furanyl, pyridyl and 3-methylimidazolyl. For example, it can be Lewis base groups in different connection modes such as 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, etc.

[0070] Amphiphilic molecules containing the above-mentioned types of Lewis base groups are used in perovskites, based on the fact that 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.

[0071] 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 Lewis acid, it is within the scope of protection of this application. Specifically, the halogen atom can be fluorine, chlorine, bromine, iodine, etc.

[0072] In one embodiment, in the amphiphilic molecule shown in Formula I, X1, X2, X3, X4, and X5 are the same halogen atoms. The fully halogenated benzene ring structure, as a Lewis acid group, can better combine with the under-coordinated anion to better passivate the under-coordinated anion of the perovskite crystal. In one embodiment, the amphiphilic molecule includes the following structure:

[0073]

[0074] The fully fluorinated benzene rings in the amphiphilic molecules serve as Lewis acid groups, which are not only structurally stable and can effectively passivate perovskite grain boundary defects, but are also easy to synthesize.

[0075] Method for preparing 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 a hydrogenation reaction to obtain the amphiphilic molecule provided by the first aspect of the embodiment of the present application;

[0078]

[0079] The compound shown in formula II is subjected to hydrogenation reaction, so that the R group and the halogen-substituted benzene ring structure are connected through a saturated carbon chain to obtain the amphiphilic molecule shown in formula I in the embodiment of the present application. The preparation method is not only simple in process and easy to implement, but also the amphiphilic molecule obtained is based on Lewis acid groups and Lewis base groups, which can passivate the surface defects of the perovskite crystal well, thereby improving the conversion efficiency and stability of the perovskite.

[0080] In one embodiment, in the compound of the starting material formula II, R, X1, X2, X3, X4, X5 and n correspond to R, X1, X2, X3, X4, X5 and n in the amphiphilic molecule of the product formula I.

[0081] 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.

[0082] 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. The synthesis of the amphiphilic molecule can be fully achieved through the hydrogenation reaction of 2 to 8 hours.

[0083] In one embodiment, the temperature of the hydrogenation reaction is 60-80° C., and the time of the hydrogenation reaction 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 realize the synthesis of amphiphilic molecules.

[0084] In one embodiment, the hydrogenation reaction is carried out under the condition of a rhodium catalyst. The addition of a rhodium catalyst can increase the addition reaction rate, thereby greatly improving the synthesis efficiency of the amphiphilic molecule shown in the product formula I. For example, the rhodium catalyst can include tris(triphenylphosphine)rhodium chloride.

[0085] In one embodiment, the hydrogenation reaction can be carried out in an alcohol solvent. The alcohol solvent can fully dissolve the raw material for hydrogenation reaction. The alcohol 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 reaction to obtain a product.

[0086] 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;

[0087]

[0088] Wherein, X' is a halogen atom.

[0089] Triethyl phosphite and the halogenated benzene ring hydrocarbon shown in formula III first undergo a nucleophilic substitution reaction, and at the same time, 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.

[0090] Take the compound shown in the raw material formula II, in which 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. Then the product after vacuum distillation is dissolved in dimethylformamide with sodium methoxide and R-formaldehyde R-CHO and stirred for 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:

[0091]

[0092] application

[0093] 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.

[0094] Based on the main existence of two kinds of defects in the perovskite crystal boundary, namely the under-coordinated anion and the under-coordinated cation, and Lewis acid and Lewis base can passivate these two defects respectively to enhance the performance of perovskite. The amphiphilic molecule shown in the formula I designed in the embodiment of the present application has a Lewis acid group and a Lewis base group at the same time, which can be used to passivate the under-coordinated anion and the under-coordinated cation of the perovskite crystal boundary, and has hydrophobic properties based on the amphiphilic molecule at the same time, 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 to improve the conversion efficiency and stability of perovskite.

[0095] Specifically, the types and preparation methods of the amphiphilic molecules shown in Formula I are described above.

[0096] Perovskite materials

[0097] In a fourth aspect, an embodiment of the present application provides a perovskite material, the perovskite material comprising a perovskite crystal and an amphiphilic molecule provided in the first aspect of the embodiment of the present application combined with the perovskite crystal and / or an amphiphilic molecule prepared by the preparation method provided in the second aspect of the embodiment of the present application.

[0098] 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 a perovskite material and combined with a perovskite crystal to passivate the grain boundary defects of the perovskite and improve the conversion efficiency and stability of the perovskite material.

[0099] In some embodiments, the perovskite chemical formula of the present application embodiment 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, which may specifically include Pb 2+ Sn 2+ At least one of; X is a monovalent anion, which may specifically include Cl - Br - and I - At least one of .

[0100] In some embodiments, the divalent cation in the perovskite is Pb 2+ , monovalent anion is I - For example. Figure 1 As shown, before using the amphiphilic molecule ( Figure 1 In a), there are two defects in the perovskite grain boundary: insufficiently coordinated iodine ions (i.e., lead ion vacancies) and insufficiently coordinated lead ions (i.e., iodide vacancies). Figure 1 In b), the Lewis acid LA group at one end of a part of the amphiphilic molecules can combine with the under-coordinated iodine ions and passivate the under-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 group at one end of the other part of the amphiphilic molecules can combine with the under-coordinated lead ions and provide lone electron pairs to the bound lead ions to passivate the iodine ion vacancy defects in the perovskite crystal.

[0101] Based on the fact that Lewis acids and Lewis bases can form adducts, the amphiphilic molecules provided in the embodiments of the present application can act as both Lewis acids and Lewis bases. The end of the amphiphilic molecule with Lewis acid flows to the exposed iodide, and the end of the amphiphilic molecule with Lewis base can also flow to the exposed uncoordinated lead ion for binding. This can effectively passivate the two grain boundary defects of the perovskite and improve the conversion efficiency and stability of the perovskite material.

[0102] 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 molecules in the above molar ratio can passivate the perovskite crystal well.

[0103] In one embodiment, the amphiphilic molecule shown in Formula I can be added separately as an additive to the perovskite precursor solvent, and the amphiphilic molecule is 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 grains 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.

[0104] 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% (as a percentage of the molar ratio of the perovskite ABX3); such an amount of amphiphilic molecules added can passivate the perovskite crystals well.

[0105] Optoelectronic devices

[0106] 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.

[0107] 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, so that the optoelectronic device has good photoelectric conversion efficiency and stability.

[0108] 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.

[0109] 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. The optoelectronic device with this structure is conducive to the transport of holes and electrons in the device, and can improve the carrier transport performance of the device, thereby further improving the photoelectric conversion efficiency.

[0110] In some embodiments, Figure 2As shown, the optoelectronic 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; wherein the perovskite layer 3 contains the perovskite material of the embodiment of the present application, and the surface of the perovskite crystal is modified and passivated with the amphiphilic molecule shown in Formula I. The perovskite material has a large grain size and a low defect state density, so that the device has good photoelectric conversion efficiency and stability. At the same time, the optoelectronic device of this structure is conducive to the transmission of holes and electrons in the device, which can improve the carrier transport performance of the device, thereby further improving the photoelectric conversion efficiency.

[0111] 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.

[0112] 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-aniline) carbazole-spirobifluorene (CzPAF-SBF), poly (3,4-ethylenedioxythiophene): poly (styrene sulfone) (PEDOT:PSS), polythiophene, nickel oxide (NiO x ), molybdenum oxide (MoO3), cuprous iodide (CuI), cuprous oxide (CuO), etc.

[0113] 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.

[0114] In some embodiments, the second electrode 5 may be a metal electrode, or may be one or more of a conductive oxide electrode.

[0115] 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, the 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.

[0116] Electrical devices

[0117] In a sixth aspect, the embodiment of the present application further provides an electric device, which includes the optoelectronic device provided in the fifth aspect of the embodiment of the present application. The optoelectronic device can be used as a photoelectric conversion device of the electric device to convert light energy into electrical energy. Therefore, the electric device of the embodiment of the present application has high photoelectric conversion efficiency and good stability, and can work better.

[0118] The electrical device of the embodiment of the present application can be, but is not limited to, household lighting and power supply. For example, when the photovoltaic device used is a solar cell, the electrical device can be installed on a roof or a courtyard to convert solar energy into electrical energy to provide lighting and power supply for the household. As another example, the electrical device can be a solar power station. For example, solar cells can be used to build a solar power station to convert solar energy into electrical energy and transmit it to the power grid to provide clean energy for the city.

[0119] Example

[0120] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0121] 1. Examples of amphiphilic molecules and methods for preparing them

[0122] Example A1

[0123] A 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, and the preparation method of the amphiphilic molecule is as follows:

[0124] C6F5CH2Br and triethyl phosphite (molar ratio 1:2) were heated at 150°C for 2 hours under nitrogen protection. The product after vacuum distillation was dissolved in dimethylformamide with 1.5 times molar equivalent of sodium methoxide and 1 times molar equivalent of 2-pyridinecarboxaldehyde. After stirring at 0°C for 15 minutes, it was stirred at room temperature for 90 minutes. After purification, drying and recrystallization, an intermediate product containing a double bond was obtained. The intermediate product was dissolved in ethanol, filled with nitrogen for 15 minutes, and then tris(triphenylphosphine)rhodium chloride accounting for 5% of the molar amount of the intermediate product was added. In the Parr apparatus, the temperature of 65°C and the hydrogen pressure of 50psi were maintained for 5 hours. After the reaction, the ethanol solvent was evaporated to remove it, and the final product C6F5-CH2CH2-2-pyridine was obtained after purification.

[0125] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 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).

[0126] Example A2

[0127] A amphiphilic molecule C6F5-CH2CH2-3-pyridine, which is different from Example A1 mainly in that R is 3-pyridyl, and the rest are the same.

[0128] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 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).

[0129] Example A3

[0130] A amphiphilic molecule C6F5-CH2CH2-4-pyridine, which is different from Example A1 mainly in that R is 4-pyridyl, and the rest are the same.

[0131] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 1H 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).

[0132] Example A4

[0133] A biphilic molecule C6F5-CH2CH2-2-furan, which is different from Example A1 mainly in that R is 2-furanyl, and the other parts are the same.

[0134] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 1 H NMR δ 7.68 (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).

[0135] Example A5

[0136] A biphilic molecule C6F5-CH2CH2-3-furan, which is different from Example A1 mainly in that R is 3-furanyl, and the other parts are the same.

[0137] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 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).

[0138] Example A6

[0139] A amphiphilic molecule C6F5-CH2CH2-2-thiophene, which is different from Example A1 mainly in that R is 2-thienyl, and the rest are the same.

[0140] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 1 H 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).

[0141] Example A7

[0142] A amphiphilic molecule C6F5-CH2CH2-3-thiophene, which is different from Example A1 mainly in that R is 3-thienyl, and the rest are the same.

[0143] The resulting amphiphilic product is 1 H NMR (DMSO-d6, 300 MHz) characterization. 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).

[0144] 2. Perovskite Solar Cell Example

[0145] Example B1

[0146] 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:

[0147] Step 1: Take an ITO conductive glass with a specification of 2.0*2.0cm, remove 0.35cm of ITO at both ends by laser etching, and expose the glass substrate; ultrasonically clean the etched ITO conductive glass several times with water, acetone, and isopropanol in sequence; blow the ITO conductive glass dry with a nitrogen gun, and put it into a UV ozone machine for further cleaning to obtain an ITO substrate treated with UV ozone;

[0148] Step 2: Spin-coat 2 mg / mL of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) at a rate of 5000 rpm / s on the UV-ozone treated ITO substrate, and anneal on a hot plate at 100° C. for 10 minutes to obtain a hole transport layer.

[0149] 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 650nm.

[0150] Step 4: Spin-coat phenyl-C61-butyric acid methyl ester (PCBM) on the perovskite layer at 1000 rpm / s, anneal at 100° C. for 10 min, and then spin-coat its passivation layer bathocuproin (BCP) at 5000 rpm / s to obtain an electron transport layer.

[0151] Step 5, placing the wafer obtained in step 4 into a vapor deposition machine, and vapor depositing a copper electrode to 80 nm at a rate of 1 A / s to complete the preparation of the entire device.

[0152] Example B2

[0153] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A2 is added to the precursor solution during the preparation of the perovskite layer.

[0154] Example B3

[0155] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A3 is added to the precursor solution during the preparation of the perovskite layer.

[0156] Example B4

[0157] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A4 is added to the precursor solution during the preparation of the perovskite layer.

[0158] Example B5

[0159] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A5 is added to the precursor solution during the preparation of the perovskite layer.

[0160] Example B6

[0161] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A6 is added to the precursor solution during the preparation of the perovskite layer.

[0162] Example B7

[0163] A perovskite solar cell is the same as Example B1 except that the amphiphilic molecule in Example A7 is added to the precursor solution during the preparation of the perovskite layer.

[0164] Example B8

[0165] A perovskite solar cell is the same as Example B7 except that the amount of the amphiphilic molecule added to the precursor solution in Example A7 is 0.01 mol% when preparing the perovskite layer.

[0166] Example B9

[0167] 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%.

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

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

[0175] In 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 (unit V), maximum light output current Jmpp (unit mA) and maximum light output voltage Vmpp (unit V). The fill factor FF of the cell is calculated by the formula FF = (Jmpp × Vmpp) / Jsc × Voc, unit %. The photoelectric conversion efficiency PCE of the cell is calculated by the formula PCE = Jsc × Voc × FF / Pw, unit %; Pw represents the input power, unit mW.

[0176] b. Perovskite solar cell stability test:

[0177] The prepared solar cell device was placed in a dry room at 65° C. hot stage for accelerated testing, wherein the humidity was 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 are shown in Table 1.

[0179] Table 1

[0180]

[0181] 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.

[0182] 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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, characterized in that The 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, characterized in that n is 1 to 9.

3. The amphiphilic molecule according to claim 1 or 2, characterized in that 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, characterized in that X1, X2, X3, X4, and X5 are the same halogen atoms.

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

6. A method for preparing an amphiphilic molecule, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that 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, characterized in that: 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, characterized in that: The electrical device comprises the optoelectronic device according to claim 13 or 14.

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