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 shown as a formula I: # imgabs0 #, R comprises a Lewis base group, X comprises at least one of hydrogen and halogen atoms, and n is an integer greater than or equal to 0. 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 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.

[0008] Utilize amphiphilic molecules to have Lewis acid (Lewis Acid, LA) group and Lewis base (Lewis Base, LB) group at the same time, specifically, R includes Lewis base group, and fullerene is Lewis acid group, such amphiphilic molecules can be used to passivate two defects of perovskite crystal boundary, namely insufficiently coordinated anions and insufficiently coordinated cations, on the one hand, fullerene as Lewis acid group can receive electrons of anions at the edge of perovskite crystal to passivate insufficiently coordinated anions of perovskite crystal, on the other hand, the lone electron pair of Lewis base at R end can be provided to insufficiently coordinated cations to passivate anion vacancy defects of perovskite crystal. R group and fullerene are connected by pyrazole ring structure, based on the large steric effect of benzene ring connected by pyrazole ring structure, amphiphilic molecules can be stably combined on perovskite crystal surface, while increasing the grains of perovskite, and the moisture resistance of perovskite can be improved based on the hydrophobicity of the amphiphilic molecules themselves. Therefore, the present application embodiment provides amphiphilic molecules that can better passivate the surface defects of perovskite crystal, thereby improving the conversion efficiency and stability of perovskite.

[0009] 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.

[0010] 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.

[0011] 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 .

[0012] The above-mentioned fullerenes can bind to under-coordinated anions as Lewis acid groups and passivate the under-coordinated anions of the perovskite crystal by accepting electrons from the anions at the edge of the perovskite crystal.

[0013] In one embodiment, n=0-10.

[0014] 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 under-coordinated anions and under-coordinated cations as needed.

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

[0016]

[0017] Fullerene C 60As a Lewis acid group, not only is the structure stable and can passivate perovskite grain boundary defects well, but the above-mentioned amphiphilic molecules are 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]

[0021] Wherein, X' is a halogen atom.

[0022] The compound shown in Formula II and fullerene are used as synthetic raw materials, and the two are subjected to an addition reaction to obtain the amphiphilic molecule shown in Formula I in the embodiment of the present application. This preparation method is not only simple in process and easy to implement, but also the amphiphilic molecule having Lewis acid groups and Lewis base groups can passivate the grain boundary defects of perovskite well, thereby improving the conversion efficiency and stability of perovskite.

[0023] In one embodiment, the temperature of the addition reaction is 70-90° C.; and / or

[0024] The addition reaction time is 2 to 8 hours.

[0025] The temperature and time of the above addition reaction can well achieve the synthesis of amphiphilic molecules.

[0026] In one embodiment, the addition reaction is carried out under triethylamine catalyst conditions; and / or,

[0027] The addition reaction is carried out in a benzene solvent.

[0028] The addition of the above catalyst can greatly improve the synthesis efficiency of the amphiphilic molecules, and the benzene solvent can provide a good environment for the synthesis of the amphiphilic molecules.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] In one embodiment, the molar ratio of the perovskite crystal to the amphiphilic molecule is 1:(0.0001-0.001).

[0034] The amphiphilic molecules in the above ratio can passivate the perovskite crystals well.

[0035] 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.

[0036] 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.

[0037] 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-C61-butyric acid methyl ester and phenyl-C61-butyric acid methyl ester.

[0038] The optoelectronic device with this structure is beneficial 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 beneficial to the current extraction of the optoelectronic device, thereby further improving the photoelectric conversion efficiency.

[0039] In one embodiment, the optoelectronic device comprises a solar cell.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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

[0044] 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:

[0045] Figure 1 : is a schematic diagram comparing the perovskite of the embodiment of the present application before and after passivation by the amphiphilic molecule;

[0046] Figure 2 is a schematic structural diagram of a solar cell according to an embodiment of the present application;

[0047] Description of reference numerals:

[0048] 1-first electrode, 2-hole transport layer, 3-perovskite layer, 4-electron transport layer, 5-second electrode. DETAILED DESCRIPTION

[0049] The following embodiments of the technical solution of the present application are 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Amphiphilic molecules

[0062] 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:

[0063]

[0064] 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.

[0065] 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.

[0066] 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 fullerene 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) fullerene 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.

[0067] In the amphiphilic molecule shown in the above formula I provided in the embodiment 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 grains of the perovskite, and the moisture resistance of the perovskite can be improved based on the hydrophobicity of the amphiphilic molecule itself. Therefore, the amphiphilic molecule provided in the embodiment of the present application can better passivate the surface defects of the perovskite crystal, thereby improving the conversion efficiency and stability of the perovskite.

[0068] In one embodiment, in the amphiphilic molecule represented by Formula I, It can be said that two adjacent carbon atoms of fullerene are connected to the pyrazole ring structure, specifically, the fullerene and the pyrazole ring structure share two adjacent carbon atoms. In this way, the fullerene connection is more stable.

[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 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 .

[0072] Fullerene is a hollow molecule composed entirely of carbon, which 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 uses the amphiphilic molecules containing the above-mentioned fullerenes in perovskite, based on the fact that the above-mentioned fullerenes can be combined with under-coordinated anions as Lewis acid groups, and passivate the under-coordinated anions in the perovskite crystal by receiving electrons from the anions at the edge of the perovskite crystal.

[0073] 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 connected to the R group and the pyrazole ring structure.

[0074] Specifically, n=0-10, so in the amphiphilic molecule shown in Formula I, the R group and the fullerene are connected by 1-10 -CH2-, 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 of Formula I can flexibly cooperate with under-coordinated anions and under-coordinated cations as needed.

[0075] In one embodiment, in the amphiphilic molecule shown in Formula I, X can be hydrogen or a halogen atom, that is, one end of the pyrazole ring structure connecting the R group and the fullerene can be connected to benzene or halogen-substituted benzene, specifically ortho-substituted, meta-substituted or para-substituted. The substituted halogen atom can be fluorine, chlorine, bromine, iodine, etc.

[0076] In one embodiment, the amphiphilic molecule comprises the following structure:

[0077]

[0078] Fullerene C60 As a Lewis acid group, not only is the structure stable and can well passivate perovskite grain boundary defects, but also the X-substituted amphiphilic molecules are easy to synthesize.

[0079] Method for preparing amphiphilic molecules

[0080] In a second aspect, the present invention provides a method for preparing an amphiphilic molecule, comprising the following steps:

[0081] 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;

[0082]

[0083] Wherein, X' is a halogen atom.

[0084] The compound shown in formula II and fullerene are used as raw materials for synthesizing the amphiphilic molecule, and the two are subjected to an addition reaction, so that X' in the compound shown in 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 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 obtained amphiphilic molecule can passivate the surface defects of the perovskite crystal well based on the Lewis acid group and the Lewis base group, thereby improving the conversion efficiency and stability of the perovskite.

[0085] In one embodiment, the raw material fullerene may be fullerene C 20 , Fullerene C 60 , Fullerene C 70 , Fullerene C 76 and fullerene C 80 X, R and n in the compound shown in the raw material formula II correspond to X, R and n in the amphiphilic molecule shown in the product formula I.

[0086] 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.

[0087] 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. The synthesis of the amphiphilic molecule can be fully achieved through the addition reaction of 2 to 8 hours.

[0088] In one embodiment, the temperature of the addition reaction is 70-90° C., and the time of the addition reaction is 2-8 hours. Under the above temperature and time conditions of the addition reaction, the compound represented by Formula II and the fullerene fully undergo addition reaction to efficiently synthesize the amphiphilic molecule.

[0089] In one embodiment, the addition reaction is carried out under the condition of triethylamine catalyst. The addition of triethylamine catalyst can increase the rate of the addition reaction, thereby greatly improving the synthesis efficiency of the amphiphilic molecule shown in the product formula I.

[0090] In one embodiment, the amount of triethylamine catalyst added may be 1-10% of the total amount of fullerenes.

[0091] In one embodiment, the addition reaction can be carried out in a benzene solvent. Specifically, the benzene solvent can include benzene or chlorobenzene. According to the principle of like dissolves like, the benzene solvent and the raw material, i.e., the compound shown in II and the fullerene, all have a benzene ring structure, so this type of solvent can fully dissolve the raw material for the addition reaction.

[0092] 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 selection of X' and X.

[0093] Taking the compound represented by the raw material formula II, X' is a chlorine atom, and X is a para-substituted chlorine atom as an example. The steps of the synthesis method of the compound represented by the formula II may include: treating 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 chlorination reaction, specifically, N-chlorosuccinimide (NCS) is added to the reaction system and stirred for 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:

[0094]

[0095] application

[0096] 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.

[0097] 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.

[0098] Specifically, the types and preparation methods of the amphiphilic molecules shown in Formula I are described above.

[0099] Perovskite materials

[0100] 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.

[0101] 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.

[0102] 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 + 、CH(NH2)2 + , Cs + 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 .

[0103] 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.

[0104] Based on the fact that Lewis acid and Lewis base can form adducts, the amphiphilic molecule provided in the embodiment of the present application can be used as both a Lewis acid and a Lewis base. The end of the amphiphilic molecule with a Lewis acid flows to the exposed iodide, and the end of the amphiphilic molecule with a Lewis base can also flow to the exposed uncoordinated lead ion for binding. In this way, the two grain boundary defects of the perovskite can be passivated well, and the conversion efficiency and stability of the perovskite material can be improved.

[0105] 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 molecules in the above molar ratio can passivate the perovskite crystal well.

[0106] 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.

[0107] 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 added can passivate the perovskite crystals well.

[0108] Optoelectronic devices

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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 and phenyl-C61-butyric acid methyl ester. The optoelectronic device of this structure is conducive to the transport of holes and electrons in the device, and can improve the carrier transport performance of the device. At the same time, the amphiphilic molecules in the perovskite layer can be well matched 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.

[0113] In some embodiments, Figure 2 As 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] Furthermore, the material of the electron transport layer 4 includes at least one of fullerene and phenyl-C61-butyric acid methyl ester. The amphiphilic molecules in the perovskite layer 3 can be well matched with the fullerene or phenyl-C61-butyric acid methyl ester or phenyl-C71-butyric acid methyl ester of the electron transport layer 4, which is beneficial to the current extraction of the photoelectric device, thereby further improving the photoelectric conversion efficiency.

[0118] In some embodiments, the second electrode 5 may be a metal electrode, or may be one or more of a conductive oxide electrode.

[0119] 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.

[0120] Electrical devices

[0121] 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.

[0122] 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.

[0123] Example

[0124] 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.

[0125] 1. Examples of amphiphilic molecules and methods for preparing them

[0126] Example A1

[0127] A bisexual 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:

[0128] The raw materials 2-pyridine carboxaldehyde and phenylhydrazine are mixed in equal amounts in dimethylformamide (DMF) solvent and stirred for reaction. Then two equivalents of N-chlorosuccinimide (NCS) are added to the reaction system, and the solution of the reaction system is stirred for chlorination reaction. Finally, the solvent is removed, and the residual solid is purified by silica gel column chromatography to obtain a product that is similar to 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 amphoteric molecules.

[0129] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1 H 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).

[0130] Example A2

[0131] A amphiphilic molecule, the main difference from Example A1 is that R is 3-pyridyl, and the other parts are the same.

[0132] The resulting amphiphilic product is 1 H NMR (300 MHz, DMSO-d6) characterization. 1H 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).

[0133] Example A3

[0134] A amphiphilic molecule, the main difference from Example A1 is that R is 4-pyridyl, and the other parts are the same.

[0135] 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).

[0136] Example A4

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

[0138] 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).

[0139] Example A5

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

[0141] 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).

[0142] Example A6

[0143] A amphiphilic molecule, the main difference from Example A1 is that R is 2-thienyl, and the other parts are the same.

[0144] 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).

[0145] Example A7

[0146] A amphiphilic molecule, the main difference from Example A1 is that R is 3-thienyl, and the other parts are the same.

[0147] 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).

[0148] 2. Perovskite Solar Cell Example

[0149] Example B1

[0150] 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:

[0151] 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;

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Example B2

[0157] 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.

[0158] Example B3

[0159] 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.

[0160] Example B4

[0161] 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.

[0162] Example B5

[0163] 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.

[0164] Example B6

[0165] 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.

[0166] Example B7

[0167] 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.

[0168] Example B8

[0169] 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.

[0170] Example B9

[0171] 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%.

[0172] Example B10

[0173] A perovskite solar cell is the same as Example B7 except that the electron transport layer material is zinc oxide.

[0174] Comparative Example 1

[0175] A solar cell is the same as Example B1 except that no amphiphilic molecules are added during the preparation of the perovskite layer.

[0176] Comparative Example 2

[0177] 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.

[0178] Performance Testing

[0179] 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 .

[0180] a. Photovoltaic conversion efficiency test of perovskite solar cells:

[0181] 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.

[0182] b. Perovskite solar cell stability test:

[0183] 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.

[0184] The specific experimental results of the above tests are shown in Table 1.

[0185] Table 1

[0186]

[0187] 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 dosage 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.

[0188] 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 general 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, characterized in that 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, characterized in that 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, characterized in that n＝0～10。 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 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, characterized in that: 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, characterized in that: 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, 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 8, which is combined with the perovskite crystal.

11. The perovskite material according to claim 10, characterized in that 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, characterized in that: The perovskite layer comprises the perovskite material according to claim 10 or 11.

13. The optoelectronic device according to claim 12, characterized in that 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-C61-butyric acid methyl ester and phenyl-C61-butyric acid methyl ester.

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

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

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