Zwitterionic molecules, their production methods and applications

Abstract

The present application discloses a zwitterionic molecule and its manufacturing method and application. The general chemical structure of the zwitterionic molecule according to the present application is shown in Formula I, where R comprises a Lewis base, X comprises at least one of hydrogen and a halogen atom, and n is an integer equal to or greater than 0. The zwitterionic molecule of the present application simultaneously contains a Lewis acid group and a Lewis base. Such a zwitterionic molecule can be used to passivate two defects, namely undercoordinated anions and undercoordinated cations, at the perovskite grain boundary. Therefore, the use of such a zwitterionic molecule in a perovskite material can significantly improve the conversion efficiency and stability of the perovskite. [Formula 1] JPEG2026505015000014.jpg54170

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from a Chinese patent application filed with the China Patent Office on June 15, 2023, bearing application number 202310712849.0 and entitled "Zipper molecule and its manufacturing method and application," the entire contents of which are incorporated herein by reference.

[0002] (Technical field) The present application belongs to the perovskite technical field, and specifically relates to zwitterionic molecules and their preparation methods and applications. [Background technology]

[0003] Perovskite materials are semiconductor nanomaterials with uniform size and high color purity, and their elemental composition has a crystalline structure similar to that of the mineral CaTiO3. Perovskite materials have a strong light absorption ability and a wide absorption range, giving them great advantages in the photovoltaic field. For example, perovskite solar cells (PSCs), which use organic-inorganic hybrid perovskite materials as a light absorption layer, are rapidly developing.

[0004] In an ideal perovskite crystal structure, each atom has its own corresponding position, but in actual perovskite, surface defects occur during crystal growth and subsequent processing. Grain boundary defects formed in perovskite crystals are prone to non-radiative complexation of carriers, thereby affecting their photoelectric conversion efficiency. Summary of the Invention

[0005] In view of the above problems, the present application provides a zwitterionic molecule and its manufacturing method and application to solve the technical problem of how to reduce perovskite grain boundary defects.

[0006] According to a first aspect, an embodiment of the present application provides a zwitterionic molecule, the general chemical structure of which is shown in Formula I: [ka] Here, R includes a Lewis base, X includes at least one of hydrogen and a halogen atom, and n is an integer of 0 or greater.

[0007] The zwitterionic molecule possesses both a Lewis acid (LA) and a Lewis base (LB), specifically, R contains a Lewis base and fullerene is a Lewis acid group. This zwitterionic molecule can be used to passivate two defects at perovskite grain boundaries, namely undercoordinated anions and undercoordinated cations. The fullerene, acting as a Lewis acid group, can accept electrons from anions at the perovskite crystal edge to passivate the undercoordinated anions in the perovskite crystal, while the lone electron pair of the Lewis base at the R end can be donated to the undercoordinated cation to passivate anion vacancy defects in the perovskite crystal. The R group and fullerene are connected via a pyrazole ring structure, and the large steric hindrance effect of the benzene ring connected by the pyrazole ring structure allows the zwitterionic molecule to stably bind to the perovskite crystal surface and increase the crystal grain size of the perovskite, while the hydrophobicity of the zwitterionic molecule itself can improve the water-repellent performance of the perovskite. Therefore, the examples of the present application provide zwitterionic molecules that can improve the conversion efficiency and stability of perovskite by better passivating surface defects of the perovskite crystal.

[0008] In one embodiment, the Lewis base comprises at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group.

[0009] The Lewis bases can bind to undercoordinated cations and provide them with lone pairs of electrons to passivate anion vacancy defects in the perovskite crystal.

[0010] In one embodiment, the fullerene in Formula I is fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 It includes at least one of the following.

[0011] The above types of fullerenes can passivate undercoordinated anions in perovskite crystals by binding to the undercoordinated anions as Lewis acid groups and accepting electrons from the anions at the perovskite crystal edges.

[0012] In one embodiment, n=0-10.

[0013] Such carbon chains can link the R group in Formula I to the fullerene, and depending on the specific defect types at the perovskite grain boundary, the zwitterionic molecule can flexibly bind to undercoordinated anions and undercoordinated cations as needed.

[0014] In one embodiment, the zwitterionic molecule is [ka] Includes.

[0015] Fullerene C in the Gemini molecule 60 By using a Lewis acid group, the structure is stable and perovskite grain boundary defects can be effectively passivated, and the synthesis of the zwitterionic molecule is easy.

[0016] According to a second aspect, embodiments of the present application provide a method for producing a zwitterionic molecule, the method comprising: Addition reaction of a compound of formula II with a fullerene to obtain a zwitterionic molecule according to a first embodiment of the present application; [ka] Here, X' is a halogen atom.

[0017] The compound of formula II and fullerene are used as synthesis raw materials, and the zwitterionic molecule of formula I in the examples of this application can be obtained by subjecting them to an addition reaction. This production method is not only simple and easy to implement, but also allows the resulting zwitterionic molecule having a Lewis acid group and a Lewis base to effectively passivate grain boundary defects in the perovskite, thereby improving the conversion efficiency and stability of the perovskite.

[0018] In one embodiment, the temperature of the addition reaction is between 70 and 90°C, and / or The addition reaction time is 2 to 8 hours.

[0019] The temperature and time of the addition reaction described above are well suited to the synthesis of zwitterionic molecules.

[0020] In one embodiment, the addition reaction is carried out under triethylamine catalyzed conditions, and / or The addition reaction is carried out in a benzene-based solvent.

[0021] The addition of the catalyst can significantly improve the synthesis efficiency of the zwitterion molecule, while the benzene-based solvent can provide a favorable environment for the synthesis of the zwitterion molecule.

[0022] According to a third aspect, the present application provides an application of the zwitterionic molecule according to the first aspect of the present application and / or the zwitterionic molecule obtained by the production method according to the second aspect of the present application as a perovskite crystal passivator.

[0023] Because the zwitterionic molecule shown in Formula I simultaneously possesses both Lewis acid and Lewis base groups, it can be used to passivate undercoordinated anions and undercoordinated cations at the perovskite grain boundaries, and therefore can act as a perovskite crystal passivator to passivate the grain boundary defects of perovskite, thereby improving the conversion efficiency and stability of perovskite.

[0024] According to a fourth aspect, an embodiment of the present application provides a perovskite material, the perovskite material comprising a perovskite crystal and a zwitterionic molecule according to the first aspect of the embodiment of the present application bound to the perovskite crystal and / or a zwitterionic molecule produced by the production method according to the second aspect of the embodiment of the present application.

[0025] This zwitterionic molecule possesses both Lewis acid and Lewis base groups and is hydrophobic, so it acts as a passivator in perovskite materials by binding to the perovskite crystals, passivating the grain boundary defects of the perovskite and improving the conversion efficiency and stability of the perovskite material.

[0026] In one embodiment, the molar ratio of the perovskite crystal to the zwitterionic molecules is 1:(0.0001 to 0.001).

[0027] The zwitterionic molecules in the above ratio can passivate the perovskite crystal well.

[0028] According to a fifth aspect, embodiments of the present application provide a photovoltaic device, the photovoltaic device comprising a perovskite layer, the perovskite layer comprising a perovskite material according to the fourth aspect of the embodiments of the present application.

[0029] Because the perovskite layer of the photovoltaic device according to the embodiment of the present application contains a specific perovskite material, the perovskite layer has fewer grain boundary defects and good water-proof performance, thereby providing the photovoltaic device with good photoelectric conversion efficiency and stability.

[0030] In one embodiment, the photovoltaic device comprises a first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode stacked together, wherein the material of the electron transport layer comprises at least one of fullerene, phenyl-C71-methyl butyrate, and phenyl-C61-methyl butyrate.

[0031] This structure of the photovoltaic device is advantageous for hole and electron transport in the device, improving the carrier transport performance of the device; the zwitterionic molecules in the perovskite layer can be well matched with the material of the electron transport layer, which is advantageous for current extraction in the photovoltaic device and further improving the photoelectric conversion efficiency.

[0032] In one embodiment, the photovoltaic device includes a solar cell.

[0033] The solar cell uses the perovskite material specific to the embodiments of the present application, thus enabling the solar cell to better convert light energy into electrical energy, and have good photoelectric conversion efficiency and stability.

[0034] According to a sixth aspect, an embodiment of the present application provides a power consuming apparatus, the power consuming apparatus including a photovoltaic device according to the fifth aspect of the embodiment of the present application.

[0035] By adopting the photovoltaic device according to the fifth aspect of the embodiment of the present application, such a power consuming device can have high photovoltaic conversion efficiency, good stability and better operation.

[0036] The above description is merely a summary of the technical solution of the present application, which can be implemented in accordance with the content of the specification, so as to make the technical means of the present application more clearly understood, and to make the above and other objectives, features and advantages of the present application more apparent, the following particularly cites specific embodiments of the present application for description. [Brief explanation of the drawings]

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings are used only for the purpose of illustrating the preferred embodiments and are not to be considered as limitations on the present application. And like reference numerals represent like elements in all drawings. In the drawings: [Figure 1] 1 is a comparative schematic diagram of a perovskite according to an embodiment of the present application before and after passivation by zwitterionic molecules. [Figure 2] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0038] The following describes in detail the embodiments of the technical solution of the present application in conjunction with the drawings. The following embodiments are only used to more clearly explain the technical solution of the present application, and are merely examples, which do not limit the protection scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art of this application, and the terms used herein are only for describing specific embodiments and are not intended to limit this application. The terms "comprises" and "having" and any variations thereof in the specification and claims of this application and the description of the drawings above are intended to cover a non-exclusive "comprise."

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only for distinguishing different objects, and should not be understood to indicate or imply relative importance, or to suggest the number, specific order, or hierarchical relationship of the technical features shown. In the description of the embodiments of the present application, unless otherwise clearly and specifically limited, "plurality" means two or more.

[0041] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Appearances of this phrase in various locations throughout the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, independent, or alternative embodiments. Those skilled in the art can explicitly or implicitly understand that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments of this application, the term "and / or" is merely a relation that describes related objects and indicates that three relations may exist. For example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. In addition, the character " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0043] In describing the embodiments of the present application, the term "plurality" refers to two or more (including two); similarly, "sets" refers to two or more (including two sets); "plurality" refers to two or more (including two); "at least one" refers to one or more (including one, two, three, etc.).

[0044] In describing the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center," "longitudinal direction," "lateral direction," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial direction," "radial direction," and "circumferential direction" are orientations or positional relationships shown in the drawings, and are intended only for the convenience of describing and simplifying the embodiments of the present application. They do not indicate or imply that the referred devices or elements must have a specific orientation or be configured and operated in a specific orientation, and therefore should not be understood as limitations on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly defined or limited, the technical terms "attached," "connected," "coupled," "fixed," etc. should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art will be able to understand the specific meanings of the above terms in the embodiments of the present application according to specific circumstances.

[0046] As traditional energy resources continue to dwindle, the development of new energy sources is receiving increasing attention. Modern society's new demand for green energy has led to the rapid development of photovoltaic devices, such as solar cells, which convert light energy into electrical energy through the photovoltaic effect. Currently, solar cells have reached the third generation, namely perovskite solar cells (PSCs). Perovskite solar cells boast advantages such as high photoelectric conversion efficiency and low power generation costs. They also have the potential to be integrated into architecture, making them a promising alternative to curtain wall decorations on high-rise buildings, achieving both daylighting and power generation.

[0047] Perovskite solar cells are solar cells that use perovskite-type organometal halide semiconductors as light-absorbing materials. As an artificially synthesized material, perovskite has been used in photovoltaic applications for some time, but its excellent performance, low cost, and commercial value have made it increasingly popular. As the light-absorbing layer in perovskite solar cells, its quality directly affects the device's conversion efficiency and stability.

[0048] Perovskites are susceptible to surface defects due to the influence of crystal growth and subsequent processing. For example, two types of defects are formed at perovskite grain boundaries: (1) undercoordination of cations, such as divalent cations, due to iodide vacancies, and (2) undercoordination of anions, such as halide ions, and non-coordination of anions at boundaries due to cation vacancies. Surface defect states formed in perovskite crystals affect the photoelectric conversion efficiency by easily causing non-radiative complexation of carriers. Currently, perovskite surface defects can be passivated by molecular modification. The most common method is modification with a single molecule, such as a Lewis base molecule. For example, there have been reports of perovskite being modified with 1-benzyl-3-hydroxypyridinium chloride (1B3HPC). 1B3HPC acts as a Lewis base to bond the perovskite surface to the low-coordination divalent cations of Lewis acids (e.g., Pb 2+) and form Lewis adducts, but their inability to passivate undercoordinated halide ions limits their improvement in solar cell performance.

[0049] Based on the above considerations, in order to simultaneously overcome the various defects of current perovskites, the embodiments of this application design a zwitterionic molecule that simultaneously has Lewis acid groups and Lewis base groups, thus simultaneously passivating the above two types of defects of perovskite, thereby further improving the performance of perovskite. Therefore, the following technical solution is proposed:

[0050] zwitterionic molecule According to a first aspect, an embodiment of the present application provides a zwitterionic molecule, the general chemical structure of which is shown in Formula I: [ka] Here, R includes a Lewis base, X includes at least one of hydrogen and a halogen atom, and n is an integer of 0 or greater.

[0051] Based on the Lewis acid and base theory, also known as the acid-base electron theory, any substance (molecule, ion, or group of atoms) that can accept an electron pair is called a Lewis acid (LA), and any substance (molecule, ion, or group of atoms) 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.

[0052] On the other hand, the zwitterionic molecule shown in Formula I according to the embodiments of the present application simultaneously has a Lewis acid group and a Lewis base. Specifically, R contains a Lewis base and can donate an electron pair, while the fullerene can accept an electron pair as a Lewis acid group. The zwitterionic molecule according to the embodiments of the present application can be used to passivate two defects at perovskite grain boundaries, namely, undercoordinated anions and undercoordinated cations. Specifically, (1) the fullerene, as a Lewis acid group, can accept electrons from anions at the perovskite crystal edge to passivate the undercoordinated anions in the perovskite crystal, and (2) the lone electron pair of the Lewis base at the R end can be donated to the undercoordinated cation to passivate anion vacancy defects in the perovskite crystal.

[0053] In the examples of the present application, the R group and fullerene are connected via a pyrazole ring structure, and a benzene ring structure is further connected to the nitrogen atom in the pyrazole ring structure. The large steric hindrance effect of the benzene ring connected by the pyrazole ring structure not only determines the molecular orientation of the product during synthesis of the zwitterionic molecule, but also stably binds the zwitterionic molecule to the perovskite crystal surface, increasing the crystal grain size of the perovskite. The hydrophobicity of the zwitterionic molecule itself can also improve the water-repellent performance of the perovskite. Therefore, the examples of the present application provide zwitterionic molecules that can better passivate surface defects of the perovskite crystal, thereby improving the conversion efficiency and stability of the perovskite.

[0054] In one embodiment, in the zwitterionic molecule of formula I: [ka] may represent that two adjacent carbon atoms of the fullerene are linked to the pyrazole ring structure, specifically, the fullerene and the pyrazole ring structure share two adjacent carbon atoms, thus making the fullerene linkage more stable.

[0055] In one embodiment, in the zwitterionic molecule of Formula I, the Lewis base in R comprises at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group. For example, the Lewis base may be a 2-thienyl group, a 3-thienyl group, a 2-furyl group, a 3-furyl group, a 2-pyridyl group, a 3-pyridyl group, or a 4-pyridyl group.

[0056] Zwitterionic molecules containing the above-mentioned types of Lewis bases can be used in perovskites, and based on these Lewis bases, they can bind to undercoordinated cations, donate lone pairs of electrons to the bound cations, and passivate anion vacancy defects in the perovskite crystals.

[0057] In one embodiment, in the zwitterionic molecule of Formula I, the fullerene is fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 It includes at least one of the following.

[0058] Fullerenes are hollow molecules made entirely of carbon, and may be spherical, ellipsoidal, cylindrical, or tubular in shape. Fullerenes contain not only six-membered rings but also five-membered rings, and sometimes seven-membered rings. Depending on the total number of carbon atoms, fullerenes can be divided into C 20 , C 60 , C 70 , C 76 , C 80 In the present application, the above-mentioned types of fullerene-containing zwitterionic molecules are used in perovskite, and can passivate undercoordinated anions in perovskite crystals by accepting electrons from anions at the perovskite crystal edge, based on the fact that the fullerenes bind to undercoordinated anions as Lewis acid groups.

[0059] In one embodiment, in the zwitterionic molecule of Formula I, n=0 to 10. Illustratively, n may be 1, 2, 4, 5, 6, 8, 10, etc. n represents the number of —CH— groups that connect the R group to the pyrazole ring structure.

[0060] Specifically, n=0-10. In the zwitterionic molecule shown in Formula I, the R group and the fullerene are linked via 1-10 -CH2- groups. The distance between the R group and the fullerene is short, making it difficult to form intermolecular adducts. Therefore, depending on the specific defect types at the perovskite grain boundary, the zwitterionic molecule can flexibly bind to undercoordinated anions and undercoordinated cations as needed.

[0061] In one embodiment, in the zwitterionic molecule shown in Formula I, X may be a hydrogen or halogen atom, i.e., benzene or a halogen-substituted benzene may be connected to one end of the pyrazole ring structure connecting the R group and the fullerene, specifically, ortho-, meta-, or para-substituted. Meanwhile, the substituted halogen atom may be fluorine, chlorine, bromine, iodine, etc.

[0062] In one embodiment, the zwitterionic molecule is [ka] This structure includes:

[0063] Fullerene C in the Gemini molecule 60 By using a Lewis acid group, the structure is stable and perovskite grain boundary defects can be effectively passivated, and the synthesis of X-para-substituted zwitterionic molecules is also easy.

[0064] Method for producing zwitterionic molecules According to a second aspect, embodiments of the present application provide a method for producing a zwitterionic molecule, the method comprising: Addition reaction of a compound of formula II with a fullerene to obtain a zwitterionic molecule according to a first embodiment of the present application; [ka] Here, X' is a halogen atom.

[0065] For example, by using the compound represented by Formula II and fullerene as raw materials for synthesizing a zwitterionic molecule and subjecting them to an addition reaction, the nitrogen atom connecting X' and the benzene ring structure in the compound represented by Formula II reacts with two adjacent carbon atoms in the fullerene to form a pyrazole ring structure, thereby obtaining the zwitterionic molecule represented by Formula I in the examples of the present application. This production method is not only simple and easy to implement, but also allows the resulting zwitterionic molecule to effectively passivate surface defects in the perovskite crystal based on Lewis acid groups and Lewis bases, thereby improving the conversion efficiency and stability of the perovskite.

[0066] In one embodiment, the raw fullerene is fullerene C 20 , fullerene C 60 , fullerene C 70 , fullerene C 76 and fullerene C 80 X, R, and n in the starting compound represented by formula II correspond to X, R, and n in the product zwitterionic molecule represented by formula I.

[0067] In one embodiment, the temperature of the addition reaction is 70 to 90°C (degrees Celsius), and for example, the temperature of the addition reaction may be 70°C, 75°C, 80°C, 85°C, 90°C, etc. The addition reaction can be well promoted under a temperature condition of 70 to 90°C.

[0068] In one embodiment, the addition reaction time is 2 to 8 hours, and for example, the addition reaction time may be 2 hours, 4 hours, 5 hours, 6 hours, 8 hours, etc. The addition reaction time of 2 to 8 hours is sufficient to synthesize the zwitterionic molecule.

[0069] In one embodiment, the addition reaction temperature is 70 to 90°C, and the addition reaction time is 2 to 8 hours. Under the above-mentioned addition reaction temperature and time conditions, the addition reaction between the compound represented by formula II and fullerene is sufficiently carried out, and the synthesis of the zwitterionic molecule is efficiently realized.

[0070] In one embodiment, the addition reaction is carried out under triethylamine catalysis conditions. The addition of triethylamine catalyst can improve the rate of the addition reaction, thereby significantly improving the synthesis efficiency of the product zwitterionic molecule of Formula I.

[0071] In one embodiment, the amount of triethylamine catalyst added may be 1 to 10% of the total amount of fullerenes.

[0072] In one embodiment, the addition reaction may be carried out in a benzene-based solvent. Specifically, the benzene-based solvent may include benzene or chlorobenzene. According to the principle of similar miscibility, the benzene-based solvent and the raw materials, i.e., the compound shown in II and fullerene, all have a benzene ring structure, so such a solvent can sufficiently dissolve the raw materials to carry out the addition reaction.

[0073] In one embodiment, X, R, and n in the starting compound of formula II correspond to X, R, and n in the product zwitterionic molecule of formula I. However, the compound of formula II may be synthesized in various ways depending on the selection of X' and X.

[0074] For example, in the compound of formula II as the starting material, X' is a chlorine atom and X is a para-substituted chlorine atom. The steps of the synthesis method for the compound of formula II are: nThe process involves mixing -CHO and phenylhydrazine, reacting them in dry dimethylformamide (DMF), and then chlorinating the resulting product. Specifically, this process may include adding N-chlorosuccinimide (NCS) to the reaction system and stirring to carry out the chlorination. Finally, after the chlorination reaction is complete, the solvent in the mixed solution is removed, and the remaining solid is purified by silica gel column chromatography to obtain the target product. In this process, phenylhydrazine is selected, and the large steric hindrance effect of the benzene ring can be utilized to determine the molecular orientation of the product. The chlorination of NCS forms a chlorine atom at the X' position, preparing it for subsequent addition to fullerene to form a pyrazole ring structure. The specific process is as follows:

[0075] [ka]

[0076] application According to a third aspect, the present application provides an application of the zwitterionic molecule according to the first aspect of the present application and / or the zwitterionic molecule obtained by the production method according to the second aspect of the present application as a perovskite crystal passivator.

[0077] Based on the existence of two main defects at perovskite grain boundaries, namely, undercoordinated anions and undercoordinated cations, Lewis acids and Lewis bases can respectively passivate these two defects to enhance perovskite performance. The zwitterionic molecule shown in Formula I designed in the examples of this application simultaneously possesses Lewis acid groups and Lewis bases, and can thus be used to passivate undercoordinated anions and undercoordinated cations at perovskite grain boundaries. Based on the hydrophobic properties of the zwitterionic molecule, the water-resistant stability of perovskite can be improved. Therefore, by using the zwitterionic molecule as a perovskite crystal passivator in the synthesis of perovskite, the surface defects of the perovskite crystal can be passivated, and the conversion efficiency and stability of perovskite can be improved.

[0078] Specifically, the types and preparation methods of the zwitterionic molecules represented by Formula I are described above.

[0079] Perovskite Materials According to a fourth aspect, an embodiment of the present application provides a perovskite material, the perovskite material comprising a perovskite crystal and a zwitterionic molecule according to the first aspect of the embodiment of the present application bound to the perovskite crystal and / or a zwitterionic molecule produced by the production method according to the second aspect of the embodiment of the present application.

[0080] The zwitterionic molecule shown in Formula I in the examples of the present application has both Lewis acid and Lewis base groups and is hydrophobic. Therefore, it can act as a passivator in perovskite materials by binding to the perovskite crystals, thereby passivating the grain boundary defects of the perovskite and improving the conversion efficiency and stability of the perovskite material.

[0081] In some embodiments, the perovskite formula of the embodiments of the present application may be ABX3, where A is a monovalent cation, which may be an organic cation or an inorganic cation, specifically CH3NH3 + , CH(NH2)2 + , Cs + B is a divalent cation, specifically Pb 2+ , Sn 2+ and X is a monovalent anion, specifically Cl - , Br - and I - may include at least one of the following:

[0082] In some embodiments, the divalent cation in the perovskite is Pb 2+ and the monovalent anion is I -For example, as shown in Figure 1, before the application of the zwitterion molecules (Figure 1a), there are two defects at the perovskite grain boundaries: undercoordinated iodide ions (i.e., lead ion vacancies) and undercoordinated lead ions (i.e., iodide vacancies). After the application of the zwitterion molecules (Figure 1b), the Lewis acid LA groups at one end of some of the zwitterion molecules can bind to the undercoordinated iodide ions and accept electrons from the iodide ions at the perovskite crystal edges, thereby passivating the undercoordinated iodide ions in the perovskite crystal. The Lewis base LB groups at one end of other zwitterion molecules can bind to the undercoordinated lead ions and donate lone electron pairs to the bound lead ions, thereby passivating the iodide ion vacancy defects in the perovskite crystal.

[0083] Based on the adduct formation between Lewis acids and Lewis bases, the zwitter molecules according to the embodiments of the present application can be used as both Lewis acids and Lewis bases. One end of the zwitter molecule with the Lewis acid can flow to exposed iodides, while the other end with the Lewis base can flow to and bind to exposed uncoordinated lead ions. This effectively passivates the two grain boundary defects in the perovskite, improving the conversion efficiency and stability of the perovskite material.

[0084] In one embodiment, the molar ratio of the perovskite crystal to the zwitterionic molecules is 1:(0.0001-0.001). For example, the molar ratio of the perovskite crystal ABX3 to the zwitterionic molecules may be 1:0.0001, 1:0.0002, 1:0.0005, 1:0.0006, 1:0.0008, 1:0.001, etc. Zwitterionic molecules with the above molar ratios can effectively passivate the perovskite crystal.

[0085] In one embodiment, the zwitterionic molecule represented by Formula I can be added alone as an additive to a perovskite precursor solvent, followed by annealing and crystallization to obtain a perovskite material with passivated zwitterionic molecules. Specifically, a perovskite precursor solution of perovskite ABX3 can be prepared, to which the zwitterionic molecules are added and stirred uniformly. The solution is then annealed at 80-100°C for 20-40 minutes, and cooled to room temperature to obtain a perovskite layer, i.e., a film-like layer, of the perovskite material. During the annealing and crystallization process, the zwitterionic molecule can relax the crystallization process of the perovskite, thereby increasing the crystal grain size of the perovskite. Meanwhile, the zwitterionic molecule, which contains both Lewis acid and Lewis base groups, has a passivating effect on the perovskite grain boundaries, thereby reducing the defect density of the perovskite layer and further improving the conversion efficiency and stability of the perovskite.

[0086] In the above process, the amount of the zwitterionic molecule added to the perovskite precursor solution may be 0.01 mol% to 0.1 mol% (molar ratio percentage in the perovskite ABX3), and such an amount of the zwitterionic molecule can effectively passivate the perovskite crystal.

[0087] Photoelectric Devices According to a fifth aspect, embodiments of the present application provide a photovoltaic device, the photovoltaic device comprising a perovskite layer, the perovskite layer comprising a perovskite material according to the fourth aspect of the embodiments of the present application.

[0088] Because the perovskite layer of the photovoltaic device according to the embodiment of the present application contains a specific perovskite material, the perovskite layer has fewer grain boundary defects and good water-proof performance, thereby providing the photovoltaic device with good photoelectric conversion efficiency and stability.

[0089] In one embodiment, the photovoltaic device includes a solar cell, which uses the perovskite material specific to the embodiments of the present application, thus enabling the solar cell to better convert light energy into electrical energy, and have good photoelectric conversion efficiency and stability.

[0090] In one embodiment, a photovoltaic device includes a stacked first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode, where the material of the electron transport layer includes at least one of fullerene, phenyl-C71-methyl butyrate, and phenyl-C61-methyl butyrate. This structure of the photovoltaic device is advantageous for hole and electron transport in the device, improving the carrier transport performance of the device. The zwitterionic molecules in the perovskite layer can be well matched with the material of the electron transport layer, which is advantageous for current extraction in the photovoltaic device, thereby further improving the photovoltaic conversion efficiency.

[0091] In some embodiments, as shown in Figure 2, a photovoltaic device includes a first electrode 1, a hole transport layer 2, a perovskite layer 3, an electron transport layer 4, and a second electrode 5, stacked together, where the perovskite layer 3 contains a perovskite material according to the embodiments of the present application, the perovskite crystal surface of which is modified and passivated with a zwitterionic molecule as shown in Formula I. The perovskite material has a large grain size and a low defect density, providing the device with good photovoltaic conversion efficiency and stability. At the same time, a photovoltaic device with this structure is advantageous for hole and electron transport in the device, improving the device's carrier transport performance and thereby further improving the photovoltaic conversion efficiency.

[0092] In some embodiments, the first electrode 1 may be a transparent conductive substrate, including but not limited to materials such as fluorine-doped tin oxide (FTO), indium-doped tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), and indium-doped zinc oxide (IZO).

[0093] In some embodiments, the hole transport layer 2 may be made of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), triptycene-cored triphenylamine (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobifluorene (CzPAF-SBF), poly(3,4-ethylenedioxythiophene):poly(styrenesulfone) (PEDOT:PSS), polythiophene, nickel oxide (NiO x ), molybdenum oxide (MoO3), cuprous iodide (CuI), cuprous oxide (CuO), and / or derivatives thereof and materials obtained by doping or passivating the same.

[0094] In some embodiments, the electron transport layer 4 can be made of methyl [6,6]-phenyl-C61-butyrate (PC61BM), methyl [6,6]-phenyl-C71-butyrate (PC71BM), fullerene C 60 (C 60 ), fullerene C 70 (C 70 ), tin dioxide (SnO2), zinc oxide (ZnO), and / or derivatives thereof and materials obtained by doping or passivating them.

[0095] Furthermore, the material of the electron transport layer 4 includes at least one of fullerene, phenyl-C71-methyl butyrate, and phenyl-C61-methyl butyrate. The zwitterionic molecules in the perovskite layer 3 can be well matched to the fullerene, phenyl-C61-methyl butyrate, or phenyl-C71-methyl butyrate of the electron transport layer 4, which is beneficial for current conduction in the photovoltaic device and thereby further improves the photoelectric conversion efficiency.

[0096] In some embodiments, the second electrode 5 may be a metal electrode or one or more of a conductive oxide electrode.

[0097] For example, if the photovoltaic device is a perovskite solar cell, the manufacturing method includes providing a first electrode 1, fabricating a hole transport layer 2 on the first electrode 1, fabricating a perovskite layer 3 on the hole transport layer 2 (specifically, fabricating the perovskite film using the manufacturing method of the examples of the present application), fabricating an electron transport layer 4 on the perovskite layer 3, and fabricating a second electrode 5 on the electron transport layer 4.

[0098] power consumption equipment According to a sixth aspect, the present application further provides a power consuming device, which includes a photovoltaic device according to the fifth aspect of the present application. The photovoltaic device may be used as a photoelectric conversion device of the power consuming device to convert light energy into electrical energy. Therefore, the power consuming device of the present application has high photoelectric conversion efficiency, good stability, and better operation.

[0099] The power consumption device in the embodiments of the present application may be, but is not limited to, home lighting and power supply. For example, if the photovoltaic device used is a solar cell, the power consumption device can be installed on a roof or in a courtyard to convert solar energy into electrical energy and provide lighting and power supply for a home. As another example, the power consumption device may be a solar power plant, for example, a solar cell can be used to build a solar power plant, convert solar energy into electrical energy and transport it to the grid, and provide clean energy for a city.

[0100] Example The following describes examples of the present application. The examples described below are illustrative and are intended to interpret the present application, but should not be understood as limitations on the present application. If no specific techniques or conditions are described in the examples, they are carried out according to the techniques, conditions, or product specifications described in documents within the field. If no manufacturer is specified for the reagents or equipment used, they are all ordinary products that are commercially available.

[0101] 1. Examples of Zwitterionic Molecules and Methods for Their Production Example A1 A zwitterionic molecule, such as shown in Formula I, where n=0, R is a 2-pyridyl group, X is a para-substituted chlorine atom, and the fullerene is C 60 The method for producing this zwitterionic molecule is as follows.

[0102] The raw materials, 2-pyridinecarboxaldehyde and phenylhydrazine, were mixed in equal amounts in dimethylformamide (DMF) solvent and stirred to react. Then, two equivalents of N-chlorosuccinimide (NCS) were added to the reaction system, and the reaction solution was stirred to carry out the chlorination reaction. Finally, the solvent was removed, and the remaining solid was purified by silica gel column chromatography. The resulting product and fullerene C were separated. 60 (2:1 molar ratio) and fullerene C 60 The mixture was then heated at 80°C for 5 hours under a 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 the zwitterionic molecule.

[0103] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 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).

[0104] Example A2 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 3-pyridyl group, but the other elements are the same.

[0105] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 1H NMR δ 9.07 (s, 1H), 8.75 (d, J =7.2 Hz, 1H), 8.30 (d, J =7.2 Hz, 1H), 7.58 (m, J =7.4 Hz, 1H), 7.60 (d, J =7.4 Hz, 2H),7.45 (d, J =7.3 Hz, 2H).

[0106] Example A3 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 4-pyridyl group, but the other elements are the same.

[0107] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 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).

[0108] Example A4 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 2-furyl group, but the other aspects are the same.

[0109] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 1 H NMRδ7.78 (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).

[0110] Example A5 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 3-furyl group, but the other aspects are the same.

[0111] The resulting zwitterionic molecule product is1 It was characterized by H NMR (300 MHz, DMSO-d6). 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).

[0112] Example A6 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 2-thienyl group, but the rest are the same.

[0113] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 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).

[0114] Example A7 This is a zwitterionic molecule, and the main difference from Example A1 is that R is a 3-thienyl group, but the rest are the same.

[0115] The resulting zwitterionic molecule product is 1 It was characterized by H NMR (300 MHz, DMSO-d6). 1 H NMRδ7.73 (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).

[0116] 2. Examples of perovskite solar cells Example B1 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 manufacturing steps are as follows:

[0117] Step 1: Take a 2.0*2.0cm ITO conductive glass and remove 0.35cm of ITO from each end using laser etching to expose the glass substrate. After etching, the ITO conductive glass is ultrasonically cleaned several times using water, acetone, and isopropyl alcohol. The solvent is then dried under a nitrogen gas gun, and the ITO conductive glass is then placed in an ultraviolet ozone machine for further cleaning to obtain an ultraviolet ozone-treated ITO substrate.

[0118] Step 2: After UV-ozone treatment, 2 mg / mL of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) was spin-coated on the ITO substrate at a rate of 5000 rpm / s and annealed on a hot stage at 100 °C for 10 min to obtain a 40 nm-thick hole-transporting layer.

[0119] Step 3: A 1.4 M MAPbI3 precursor solution was prepared, and the zwitterionic molecule from Example A1 was added (0.05 mol% of MAPbI3). After uniform stirring, the solution was spin-coated onto the hole-transporting layer at 3000 rpm / s, annealed at 100 °C for 30 min, and cooled to room temperature to obtain a 650 nm-thick MAPbI3 perovskite layer with passivated zwitterionic molecules.

[0120] Step 4: Phenyl-C61-methyl butyrate (PCBM) was spin-coated onto the perovskite layer at 1000 rpm / s, annealed at 100 °C for 10 min, and then immediately spin-coated at 5000 rpm / s with a passivation layer of bathocuproine (BCP) to form an electron transport layer. The PCBM layer was 30 nm thick, and the BCP layer was 10 nm thick.

[0121] Step 5: The sheet obtained in step 4 was placed in a deposition machine, and copper electrodes were deposited to a thickness of 80 nm at a rate of 1 A / s, completing the fabrication of the entire device.

[0122] Example B2 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A2 was added to the precursor solution when the perovskite layer was fabricated.

[0123] Example B3 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A3 was added to the precursor solution when the perovskite layer was fabricated.

[0124] Example B4 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A4 was added to the precursor solution when the perovskite layer was fabricated.

[0125] Example B5 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A5 was added to the precursor solution when the perovskite layer was fabricated.

[0126] Example B6 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A6 was added to the precursor solution when the perovskite layer was fabricated.

[0127] Example B7 The perovskite solar cell was the same as that of Example B1, except that the zwitterionic molecule in Example A7 was added to the precursor solution when the perovskite layer was fabricated.

[0128] Example B8 The perovskite solar cell was the same as in Example B7, except that the amount of the zwitterionic molecule in Example A7 added to the precursor solution when the perovskite layer was fabricated was 0.01 mol%.

[0129] Example B9 The perovskite solar cell was the same as in Example B7, except that the amount of the zwitterionic molecule in Example A7 added to the precursor solution when the perovskite layer was fabricated was 0.1 mol%.

[0130] Example B10 This perovskite solar cell is the same as Example B7, except that the electron transport layer material is zinc oxide.

[0131] Comparative Example 1 The solar cell was the same as Example B1, except that no zwitterionic molecules were added when the perovskite layer was fabricated.

[0132] Comparative Example 2 A solar cell, the same as Example B1, except that the zwitterionic molecule in Example A1 was replaced with 1-benzyl-3-hydroxypyridinium chloride when the perovskite layer was prepared.

[0133] Performance Test Standard simulated sunlight (AM 1.5G, 100 mW / cm 2 The efficiency of the perovskite solar cell was tested under continuous light irradiation under a 1000-kJ / s saturation temperature of 1000°C (3200°F) and its light irradiation stability was tested. The effective area of ​​the test device was 0.08 cm. 2 is.

[0134] a. Photoelectric conversion efficiency test of perovskite solar cells: Standard simulated sunlight (AM 1.5G, 100 mW / cm 2 The solar cell was tested under irradiation to obtain an IV curve. The short circuit current Jsc (unit: mA / cm) was calculated based on the IV curve and the data fed back from the test equipment. 2), open circuit voltage Voc (unit: V), maximum optical output current Jmpp (unit: mA), and maximum optical output voltage Vmpp (unit: V) were obtained. The fill factor FF of the battery was calculated using the formula FF = (Jmpp × Vmpp) / Jsc × Voc, in units of %, and the photoelectric conversion efficiency PCE of the battery was calculated using the formula PCE = Jsc × Voc × FF / Pw, in units of %, where Pw represents the input power in mW.

[0135] b, Perovskite solar cell stability test: The manufactured solar cell devices were placed in a dry room and subjected to a hot stage accelerated test at 65°C, where the humidity was set to 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.

[0136] The specific experimental results of the above tests are shown in Table 1.

[0137] [Table 1]

[0138] As can be seen from the test results in Table 1, because the perovskite layer of the perovskite solar cell was passivated using the zwitterionic molecule specific to the examples of the present application, not only did the examples of the present application have better light conversion efficiency than the comparative examples, but the efficiency stability of the solar cell devices of the examples of the present application was also better. By appropriately increasing the dosage of the zwitterionic molecule, the passivation effect was better, and when combined with the electron transport layer material fullerene or phenyl-C61-methyl butyrate, the effect was even better.

[0139] Finally, it should be noted that the above examples are merely illustrative of the technical solutions of the present application and are not intended to limit the same. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the technical solutions described in the above examples may still be modified or some or all of the technical features may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the relevant technical solutions from the scope of the technical solutions of the examples of the present application, and should all be included in the scope of the claims and description of the present application. In particular, as long as there is no structural conflict, the technical features recited in the examples may be combined in any manner. The present application is not limited to the specific examples disclosed herein, but includes all technical solutions included within the scope of the claims. [Explanation of symbols]

[0140] 1 - first electrode, 2 - hole transport layer, 3 - perovskite layer, 4 - electron transport layer, 5 - second electrode.

Claims

1. A zwitterionic molecule, the general chemical structure of which is shown in Formula I: 【Chemistry 1】 wherein R comprises a Lewis base, X comprises at least one of hydrogen and halogen atoms, and n is an integer of 0 or greater.

2. 2. The zwitterionic molecule of claim 1, wherein the Lewis base comprises at least one of a thienyl group, a furyl group, a pyridyl group, and a 3-methylimidazolyl group.

3. The fullerene in formula I is fullerene C ２０ , fullerene C ６０ , fullerene C ７０ , fullerene C ７６ and fullerene C ８０ The zwitterionic molecule of claim 1 or 2, comprising at least one of:

4. The zwitterionic molecule of any one of claims 1 to 3, wherein n=0 to 10.

5. The zwitterionic molecule is 【Chemistry 2】 The zwitterionic molecule of claim 1 , comprising:

6. 1. A method for producing a zwitterionic molecule, comprising: The method includes the step of adding a compound represented by formula II to a fullerene to obtain a zwitterionic molecule according to any one of claims 1 to 5, 【Transformation 3】 wherein X' is a halogen atom.

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

8. the addition reaction is carried out under triethylamine catalysis conditions, and / or 8. The method according to claim 6, wherein the addition reaction is carried out in a benzene-based solvent.

9. 9. Use of the zwitterionic molecule according to any one of claims 1 to 5 and / or the zwitterionic molecule obtained by the method according to any one of claims 6 to 8 as a perovskite crystal passivator.

10. A perovskite material comprising a perovskite crystal and a zwitterionic molecule according to any one of claims 1 to 5 and / or a zwitterionic molecule produced by the production method according to any one of claims 6 to 8, which is bound to the perovskite crystal.

11. 11. The perovskite material according to claim 10, wherein the molar ratio of the perovskite crystals to the zwitterionic molecules is 1:(0.0001-0.001).

12. 12. An optoelectronic device comprising a perovskite layer, the perovskite layer comprising the perovskite material of claim 10 or 11.

13. 13. The photovoltaic device of claim 12, wherein the photovoltaic device comprises a first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode stacked together, wherein a material of the electron transport layer comprises at least one of fullerene, phenyl-C71-methyl butyrate, and phenyl-C61-methyl butyrate.

14. The photovoltaic device of claim 12 or 13, wherein the photovoltaic device comprises a solar cell.

15. A power consuming apparatus comprising a photovoltaic device according to any one of claims 12 to 14.

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