Phosphonium salts, methods of making the same, perovskite cells and applications

Abstract

The application provides an onium salt, a preparation method thereof, a perovskite battery and application. The structure of the onium salt is shown in formula (A): wherein Ar 1 and Ar 2 are independently selected from any one of a substituted or unsubstituted aryl group with 6-30 ring atoms, a substituted or unsubstituted heteroaryl group with 5-30 ring atoms; and represents Ar 1 and Ar 2 are cycled with iodine ions or not. The onium salt can be used as a lithium-free and volatile-free oxidant dopant, can reduce the probability of ion erosion, interface defects and component volatilization of a hole transport layer, and can realize high photoelectric conversion efficiency and excellent humid heat long-term stability.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an onium salt, its preparation method, perovskite batteries and their applications. Background Technology

[0002] Perovskite solar cells, with their outstanding advantages such as high absorption coefficient, long carrier diffusion length, solution-processable nature, and low manufacturing cost, have become a core research direction in the next generation of photovoltaics. Nip-in-the-loop (NIP) perovskite solar cells are currently the fastest-growing device structure for industrialization. The hole transport layer plays a crucial role in the extraction and transport of photogenerated holes, as well as blocking electron-hole recombination. The film morphology, energy level matching, carrier conductivity, and interface passivation effect directly determine the cell's photoelectric conversion efficiency, hysteresis strength, and long-term stability under humid and hot conditions, making them the core research targets for hole transport layer material development.

[0003] In traditional technologies, the most commercially mature small-molecule hole transport material is 9,9'-spirodifluorenylSpiro-OMeTAD. Its orthogonally twisted molecular framework can form amorphous uniform films, providing a good energy level fit with the perovskite layer. However, this material has inherent, unavoidable defects: Spiro-OMeTAD side chains only have a single methoxy substituent group, resulting in limited aniline radical activity. The Spiro+ ions generated after oxidation are easily reduced by iodide ions in the system, leading to irreversible dedoping and causing a continuous decay of carrier concentration inside the device, significantly shortening battery life. Simultaneously, the molecular structure lacks effective interface passivation sites, resulting in severe non-radiative recombination losses at the perovskite / hole transport layer interface, limiting further improvements in open-circuit voltage and photoelectric efficiency. To improve the conductivity of Spiro-OMeTAD, a common approach is to simultaneously add oxide dopants: lithium salt LiTFSI (lithium bis(trifluoromethanesulfonylimide)) and 4-tert-butylpyridine (tBP). However, these two types of additives introduce new stability limitations: Li + With its small ionic radius, lithium salt can easily penetrate the perovskite crystal lattice. At the same time, lithium salt has strong hygroscopic properties, and water vapor intrusion will accelerate the decomposition of the perovskite film, seriously damaging the long-term working stability of the device. Furthermore, the tBP component is highly volatile and is easily lost during spin coating, causing a large number of interface defects such as pinholes and salt agglomeration in the hole transport layer film, which further aggravates the hysteresis effect and performance degradation.

[0004] Therefore, traditional technologies still need further improvement. Summary of the Invention

[0005] Based on this, this application provides an onium salt, its preparation method, perovskite solar cells and applications. As a lithium-free and non-volatile oxidant dopant, the onium salt can reduce the probability of ion erosion, interface defects and component volatilization in the hole transport layer, while achieving high photoelectric conversion efficiency and excellent long-term stability under humid heat.

[0006] The technical solution of this application is as follows:

[0007] A first aspect of this application provides an onium salt, the structure of which is shown in formula (A): , Among them, Ar 1 and Ar 2 Each is independently selected from: any one of the following: aryl groups with 6-30 substituted or unsubstituted ring atoms, and heteroaryl groups with 5-30 substituted or unsubstituted ring atoms; "Represents Ar" 1 and Ar 2 It may or may not form a ring with iodide ions.

[0008] The aforementioned onium salts contain bis(trifluoromethanesulfonyl)imide diaryl groups as anionic structures and specific iodide-containing ions as cationic structures to form onium salts. As an oxidizing dopant, they are used to prepare perovskite solar cells. In particular, when used to prepare hole transport layers, they are lithium-free and non-volatile, eliminating lithium-ion lattice penetration, reducing the probability of ion erosion, interface defects, and component volatilization in the hole transport layer. The film formation quality is uniform, without pinholes or salt aggregation, achieving high photoelectric conversion efficiency and excellent long-term stability under humid heat.

[0009] In some embodiments, the onium salt includes at least one of formula (A-1) and formula (A-2): ; In equation (A-2) Representative: Ar 1 and Ar 2 It fuses with iodide ions to form a ring.

[0010] In some embodiments, the Ar 1 and Ar 2 Each is independently selected from any one of the following: an aryl group with 6-15 unsubstituted ring atoms, an aryl group with 6-15 ring atoms substituted by a first substituent, a heteroaryl group with 5-15 unsubstituted ring atoms, and a heteroaryl group with 5-15 ring atoms substituted by a second substituent; The first substituent and the second substituent are each independently selected from any one of the following: alkyl groups having 1-7 carbon atoms, alkoxy groups having 1-7 carbon atoms, nitro groups, amino groups, halogen groups, aryl groups having 6-10 ring atoms, substituted or unsubstituted aryloxy groups having 6-10 ring atoms, substituted or unsubstituted heteroaryloxy groups having 5-10 ring atoms, and heteroaryl groups having 5-10 ring atoms.

[0011] In some embodiments, the aryl group is selected from any one of: phenyl, naphthyl, indene, benzocyclopentyl; and / or The heteroaryl group is selected from any one of pyridyl, thienyl, thiazolyl, imidazolyl, and quinolinyl.

[0012] In some embodiments, the onium salt includes at least one of the following structures:

[0013]

[0014] .

[0015] A second aspect of this application provides a method for preparing the onium salt of the first aspect, comprising the following steps: The compound of formula (a) was subjected to an exchange reaction with a bis(trifluoromethanesulfonyl)imide salt to obtain the onium salt shown in formula (A): ; Among them, X - It represents the anion of the acid radical.

[0016] In some embodiments, the molar ratio of the compound of formula (a) to the bis(trifluoromethanesulfonyl)imide salt is (0.8~1.2):1; and / or The bis(trifluoromethanesulfonyl)imide salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, and calcium bis(trifluoromethanesulfonyl)imide.

[0017] In a third aspect of this application, the use of the onium salt of the first aspect as an oxide dopant is provided.

[0018] In some embodiments, the application is the use of the onium salt as an oxide dopant in the preparation of the hole transport layer of a perovskite solar cell.

[0019] In a fourth aspect, this application provides a hole transport composition comprising a hole transport material and an oxide dopant, wherein the oxide dopant comprises the onium salt of the first aspect.

[0020] In some embodiments, the oxide dopant accounts for 2%-25% of the total mass of the hole transport composition; and / or The hole transport material comprises the compound shown in formula (B) below: (B).

[0021] In a fifth aspect, this application provides a perovskite solar cell, the perovskite solar cell comprising the onium salt of the first aspect or the hole transport composition of the fourth aspect.

[0022] In some embodiments, the perovskite solar cell includes, in sequence, a first electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a second electrode, wherein the hole transport layer comprises the onion salt or the hole transport composition.

[0023] In some embodiments, the mass percentage of the onium salt is 2% to 25% based on the total mass of the hole transport layer; and / or The hole transport layer further includes a hole transport material, which comprises a compound as shown in formula (B): (B).

[0024] The compound shown in formula (B) above is a novel derivative based on traditional spiro[fluorene-9,9'-oxazanthene] cavitation materials (e.g., Spiro-OMeTAD). It features a completely new molecular skeleton and modified side-chain substitution structures, reducing aniline radical activity and alleviating the Spiro-related issues in traditional materials. + This method reduces the doping problem and introduces passivation sites to suppress iodine ion interfacial radiative recombination, effectively maintaining carrier concentration and improving the photoelectric conversion efficiency of the battery. In particular, when it is used in combination with the onium salt of this application to prepare the hole transport layer, its efficiency and stability are especially excellent.

[0025] A sixth aspect of this application provides a photovoltaic module, the photovoltaic module comprising the perovskite cell of the fifth aspect. Attached Figure Description

[0026] Figure 1 The hydrogen nuclear magnetic resonance spectrum of Spiro-FX obtained in Example 1; Figure 2 The 1H NMR spectrum of the bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 3; Figure 3 The 1H NMR spectrum of (4-methoxyphenyl)(trimethylmethyl)bis(trifluoromethanesulfonyl)imine salt prepared in Example 4; Figure 4 The 1H NMR spectrum of the bis(4-methoxyphenyl)iodonium iodonium bis(trifluoromethanesulfonyl)imine salt prepared in Example 5; Figure 5 The 1H NMR spectrum of (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 6; Figure 6 This is a comparison image of the oxidized solution A containing the hole transport precursor of compound Spiro-FX prepared in Example 7 before and after oxidation. Detailed Implementation

[0027] To facilitate understanding of this application, a more complete description is provided below, along with preferred embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0028] 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 to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0030] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints. Any endpoint can be included or excluded independently, and they can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥ 2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0031] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] One embodiment of this application provides an onium salt, the structure of which is shown in formula (A): , Among them, Ar 1 and Ar 2 Each is independently selected from: any one of the following: aryl groups with 6-30 substituted or unsubstituted ring atoms, and heteroaryl groups with 5-30 substituted or unsubstituted ring atoms; "Represents Ar"1 and Ar 2 It may or may not form a ring with iodide ions.

[0034] The aforementioned onium salt contains bis(trifluoromethanesulfonyl)imide diaryl group as the anionic structure and a specific iodide-containing ion as the cationic structure to form an onium salt. As an oxide dopant, it is used to prepare perovskite solar cells. In particular, when used to prepare hole transport layers, it is lithium-free and non-volatile, which can eliminate lithium ion lattice penetration, reduce the probability of ion erosion, interface defects and component volatilization in hole transport layers, and produce uniform film quality without pinholes or salt aggregation, thus achieving high photoelectric conversion efficiency and excellent long-term stability under humid heat.

[0035] In some embodiments, the onium salt includes at least one of formula (A-1) and formula (A-2): ; In equation (A-2) Representative: Ar 1 and Ar 2 It fuses with iodide ions to form a ring.

[0036] Furthermore: in Ar 1 and Ar 2 When it fuses with iodide ions to form a ring, it is Ar 1 and Ar 2 The ring atoms in the ring fuse with iodide ions to form rings, which can form known fused ring structures common in this field, such as five-membered rings and six-membered rings.

[0037] In some of these embodiments, in Ar 1 and Ar 2 It fuses with iodide ions to form a five-membered ring.

[0038] In some of these embodiments, Ar 1 and Ar 2 Each is independently selected from any one of the following: an aryl group with 6-15 unsubstituted ring atoms, an aryl group with 6-15 ring atoms substituted by a first substituent, a heteroaryl group with 5-15 unsubstituted ring atoms, and a heteroaryl group with 5-15 ring atoms substituted by a second substituent.

[0039] In some of these embodiments, Ar 1 and Ar 2 Each is independently selected from any one of the following: an aryl group with 6-10 unsubstituted ring atoms, an aryl group with 6-10 ring atoms substituted by a first substituent, a heteroaryl group with 5-10 unsubstituted ring atoms, and a heteroaryl group with 5-10 ring atoms substituted by a second substituent.

[0040] In some of these embodiments, Ar 1 and Ar 2 Each is independently selected from any one of the following: aryl groups with 6-10 ring atoms substituted by the first substituent, heteroaryl groups with 5-10 unsubstituted ring atoms, and heteroaryl groups with 5-10 ring atoms substituted by the second substituent.

[0041] Understandable: Ar 1 and Ar 2 They can be the same or different.

[0042] In some of these embodiments, any one of phenyl, naphthyl, indene, and benzocyclopentyl is used.

[0043] In some embodiments, the heteroaryl group is selected from any one of pyridyl, thienyl, thiazolyl, imidazolyl, and quinolinyl.

[0044] It should be noted that when the first substituent replaces the aryl group or the second substituent replaces the heteroaryl group, the substitution site can be any substituted position on the aryl or heteroaryl group, and one or more sites of the same aryl or heteroaryl group can be substituted. When multiple sites are substituted, the substituents at each substitution site can be the same or different.

[0045] In some embodiments, the first substituent and the second substituent are each independently selected from any one of the following: alkyl groups having 1-7 carbon atoms, alkoxy groups having 1-7 carbon atoms, nitro groups, amino groups, halogen groups, aryl groups having 6-10 ring atoms, substituted or unsubstituted aryloxy groups having 6-10 ring atoms, substituted or unsubstituted heteroaryloxy groups having 5-10 ring atoms, and heteroaryl groups having 5-10 ring atoms.

[0046] In some embodiments, the first substituent and the second substituent are each independently selected from any one of the following: alkyl groups having 1-5 carbon atoms, alkoxy groups having 1-5 carbon atoms, nitro groups, amino groups, halogen groups, aryl groups having 6-10 ring atoms, substituted or unsubstituted aryloxy groups having 6-10 ring atoms, substituted or unsubstituted heteroaryloxy groups having 5-10 ring atoms, and heteroaryl groups having 5-10 ring atoms.

[0047] In some embodiments, the first substituent and the second substituent are each independently selected from: a straight-chain alkyl group having 1-5 carbon atoms, a branched alkyl group having 3-5 carbon atoms, a straight-chain alkoxy group having 1-5 carbon atoms, a branched alkoxy group having 3-5 carbon atoms, a nitro group, an amino group, a halogen group, an aryl group having 6-10 ring atoms, an unsubstituted aryloxy group having 6-10 ring atoms, an aryloxy group having 6-10 ring atoms substituted with a third substituent, a heteroaryloxy group having 5-10 ring atoms substituted with a fourth substituent, an unsubstituted heteroaryloxy group having 5-10 ring atoms, and a heteroaryl group having 5-10 ring atoms.

[0048] In some embodiments, the third substituent and the fourth substituent are each independently selected from any one of the following: alkyl groups having 1-5 carbon atoms, alkoxy groups having 1-5 carbon atoms, nitro groups, amino groups, halogen groups, aryl groups having 6-10 ring atoms, and heteroaryl groups having 5-10 ring atoms.

[0049] In some embodiments, the third and fourth substituents are each independently selected from any one of the following: alkyl groups having 1-5 carbon atoms, alkoxy groups having 1-5 carbon atoms, nitro groups, amino groups, halogen groups, phenyl groups, naphthyl groups, indole groups, benzocyclopentyl groups, pyridyl groups, thienyl groups, thiazolyl groups, imidazolyl groups, and quinolinyl groups.

[0050] In some embodiments, the halogen group includes any one of -F, -Cl, and -Br.

[0051] In some embodiments, the onium salt includes at least one of the following structures:

[0052]

[0053] .

[0054] According to one embodiment of this application, a method for preparing the above-mentioned onium salt is provided, including the following step S10.

[0055] The compound of formula (a) was subjected to an exchange reaction with a bis(trifluoromethanesulfonyl)imide salt to obtain the onium salt shown in formula (A): ; Among them, X -It represents the anion of the acid radical.

[0056] In some embodiments, the molar ratio of the compound of formula (a) to the bis(trifluoromethanesulfonyl)imide salt is (0.8~1.2):1.

[0057] In some embodiments, the bis(trifluoromethanesulfonyl)imide salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, calcium bis(trifluoromethanesulfonyl)imide, etc.

[0058] In some embodiments, the acid radical anion includes strong acid radical ions, including but not limited to: any one of toluenesulfonate ion, trifluoromethanesulfonate ion, trifluoroacetate ion, perfluorobutyrate ion, methanesulfonate ion, camphorsulfonate ion, aminosulfonate ion, hexafluorophosphate ion, fluoroborate ion, and hexafluoroantimonate ion.

[0059] In some of these embodiments, the exchange reaction is carried out at room temperature, for example, 20-30°C.

[0060] In some of these embodiments, the exchange reaction is carried out in an inert environment and in a solvent.

[0061] Specifically, an inert environment can be a nitrogen environment.

[0062] In some of these embodiments, the solvent includes at least one of acetonitrile, ethanol, methanol, dichloromethane, tetrahydrofuran, and ethyl acetate.

[0063] Furthermore, this application does not specify the amount of solvent used; the amount of solvent used in chemical reactions known to those skilled in the art can be used to achieve the purpose of mixing.

[0064] In some embodiments, the time for the above-mentioned exchange reaction is 2-24 h; for example, it can be a range of one or any combination of 2 h, 4 h, 8 h, 12 h, 16 h, 24 h.

[0065] In some embodiments, after the exchange reaction is complete, the following post-processing steps are also included: The obtained product was subjected to solvent removal and column chromatography separation and purification processes in sequence.

[0066] In this application, the solvent removal method is a method well known to those skilled in the art, including but not limited to: rotary evaporation, distillation, etc.

[0067] Specifically, the parameters for column chromatography separation and purification include: a neutral alumina column, dichloromethane and methanol as eluents, and a elution polarity of pure CH2Cl2 / MeOH = 10:1 (V / V).

[0068] Unless otherwise specified in this application, the raw material compound of formula (a) and the bis(trifluoromethanesulfonyl)imide salt in step S10 above can be prepared from commercially available products or by methods well known to those skilled in the art.

[0069] For example, when Ar in compound (a) 1 and Ar 2 When it does not form a ring with iodide ions, the structure of compound (a) is as follows: The synthetic route is as follows:

[0070] Wherein, Acid is X. - The corresponding acid, mPCPBA, is m-chloroperoxybenzoic acid; Ar 1 and Ar 2 The choice is the same as above, and will not be repeated.

[0071] The steps include: dissolving compounds (f) and (h) in an organic solvent, and then adding mCPBA and acid to react.

[0072] The product after the mixed reaction was extracted to collect the organic phase. After removing the solvent from the organic phase, it was recrystallized.

[0073] In some embodiments, the mixing reaction is carried out under the protection of an inert gas; including but not limited to: a nitrogen atmosphere.

[0074] In some embodiments, the molar ratio of compound (f) to compound (h) is 1:(2-4); for example, it can be a range of values ​​consisting of one or any two of 1:2, 1:2.5, 1:3, 1:3.5, 1:4.

[0075] In some embodiments, the molar ratio of compound (f) to mCPBA is 1:(1.05-1.2); for example, it can be a range of values ​​consisting of one or any two of 1:1.05, 1:1.1, 1:1.15, 1:2.

[0076] In some embodiments, the molar ratio of compound (f) to acid is 1:(2-4).

[0077] In some embodiments, the acid includes at least one of p-toluenesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, perfluorobutyric acid, methanesulfonic acid, camphorsulfonic acid, aminosulfonic acid, hexafluorophosphate, fluoroboric acid, and hexafluoroantimonic acid.

[0078] Understanding: X - An anionic group represents the anion formed after an acid loses a hydrogen ion, such as toluenesulfonate group, trifluoromethanesulfonate group, trifluoroacetic acid group, perfluorobutanesulfonate group, methanesulfonate group, camphorsulfonate group, aminosulfonic acid group, hexafluorophosphate group, fluoroborate group, and hexafluoroantimonate group.

[0079] In some embodiments, the solvent used for the mixed reaction includes at least one of dichloromethane, chloroform, 1,2-dichloroethane, ethyl acetate, acetonitrile, trifluoroethanol, and hexafluoroisopropanol.

[0080] It should be noted that there are no special provisions for the amount of solvent used in this application; the amount of solvent used in chemical reactions that is well known to those skilled in the art can be used.

[0081] In some embodiments, the reaction temperature is 30°C-70°C, and the specific reaction temperature may be determined according to the boiling point of the solvent; for example, the reaction temperature is 35°C when the solvent is dichloromethane, 60°C when the solvent is ethyl acetate, and 50°C-70°C when the solvent is acetonitrile.

[0082] In some implementations, the mixing reaction time is 2-24 hours. For example, it can be a range of one or any combination of 2 hours, 4 hours, 8 hours, 12 hours, 16 hours, and 24 hours.

[0083] In some embodiments, the extraction reagents are ethyl acetate and deionized water in a volume ratio of 1:1, and the aqueous phase can remove excess strong acid.

[0084] Specifically, the reagent used for recrystallization was acetonitrile. After extraction to remove the solvent, acetonitrile was added and dissolved by sonication. Crystals were precipitated in a -20°C freezer and the product was obtained by filtration.

[0085] The above preparation method is for illustrative purposes only, and the raw materials used in this application are not limited to those prepared by the above method.

[0086] One embodiment of this application provides the use of the above-mentioned onion salt as an oxide dopant.

[0087] In some embodiments, the above application is the use of onium salts as oxide dopants in the preparation of hole transport layers in perovskite solar cells.

[0088] One embodiment of this application provides a hole transport composition comprising a hole transport material and an oxide dopant, wherein the oxide dopant comprises an onium salt as described above.

[0089] In some embodiments, the proportion of oxide dopant is 2%-25% based on the total mass of the hole transport composition. Specifically, it can be any value or a range of any two of the following: 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 25%.

[0090] In some embodiments, the hole transport material comprises a compound as shown in formula (B): (B).

[0091] One embodiment of this application provides a perovskite battery, which includes the above-described onium salt or the above-described hole transport composition.

[0092] In some embodiments, the perovskite solar cell includes, in sequence, a first electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a second electrode, wherein the hole transport layer comprises the above-mentioned onium salt or the above-mentioned hole transport composition.

[0093] In some embodiments, the mass percentage of onium salt is 2% to 25% based on the total mass of the hole transport layer; specifically, it can be any value or a range of any two values ​​from 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 25%.

[0094] In some embodiments, the hole transport layer further includes a hole transport material, which comprises a compound as shown in formula (B): (B).

[0095] The compound shown in formula (B) above is a novel derivative based on traditional spiro[fluorene-9,9'-oxazanthene] cavitation materials (e.g., Spiro-OMeTAD). It features a completely new molecular skeleton and modified side-chain substitution structures, reducing aniline radical activity and alleviating the Spiro-related issues in traditional materials. + This approach addresses the issue of doping reduction while simultaneously introducing passivation sites to suppress iodine ion interfacial radiative recombination, effectively maintaining carrier concentration and improving the photoelectric conversion efficiency of the battery.

[0096] It should be noted that the above-mentioned hole transport material can be the compound shown in Formula (B) alone, a conventional hole transport material alone, or a mixture of the compound shown in Formula (B) and a conventional hole transport material in any proportion.

[0097] In some embodiments, the synthetic route of the compound shown in formula (B) is as follows:

[0098] The specific preparation process includes the following steps: Step (1): Under the protection of an inert gas, 2,7-dibromo-9H-fluorene-9-one, 3-bromophenol, and methanesulfonic acid were added to a reaction flask to carry out the first reaction. After cooling, the reaction solution was used to precipitate a solid with ice-cold solvent, and the solid was washed, filtered, and dried to obtain a white solid of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthracene].

[0099] Step (2): Under inert gas protection, 4-methoxyaniline, 4-bromobenzyl sulfide, the first catalyst, the first base, and the first ligand are mixed evenly, the second solvent is added, and the mixture is heated to carry out the second reaction. The reaction is monitored by TLC. After the reaction is completed and the mixture is cooled, it is extracted with dichloromethane / water, the organic phase is collected, the organic phase is dried with anhydrous sodium sulfate, the solvent is filtered and evaporated, and the mixture is separated and purified by column chromatography using a polar gradient elution method. The eluent is dichloromethane / petroleum ether = 1:10 → 1:2 (v / v). The solvent in the collected liquid is evaporated and dried to obtain a white solid, which is 4-methoxy-4'-methylthiodiphenylamine.

[0100] Step (3): Under inert gas protection, 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene], 4-methoxy-4'-methylthiodiphenylamine, the second catalyst, the second base, and the second ligand were mixed evenly, and the third solvent was added. The mixture was heated to carry out the third reaction, which was monitored by TLC. After the reaction was completed and the mixture was cooled, it was extracted with dichloromethane / water, and the organic phase was collected. The organic phase was dried with anhydrous sodium sulfate, and the catalyst was removed by filtration with diatomaceous earth. The solvent was evaporated, and the mixture was recrystallized with ethyl acetate, filtered, and dried to obtain a white solid, which is the compound (code) Spiro-FX shown in formula (B).

[0101] In some embodiments, in the first reaction, the molar ratio of 2,7-dibromo-9H-fluorene-9-one and 3-bromophenol is 1:(4-6); for example, it can be a range of values ​​consisting of one or any two of 1:4, 1:4.5, 1:5, 1:5.5, 1:6.

[0102] In some embodiments, the molar ratio of 2,7-dibromo-9H-fluorene-9-one to methanesulfonic acid is 1:(4-8); for example, it can be a range of values ​​consisting of one or any two of 1:4, 1:5, 1:6, 1:7, 1:8.

[0103] In some embodiments, methanesulfonic acid and 3-bromophenol are liquids, and excess amounts also serve as the first reaction solvent.

[0104] In some implementations, the first reaction temperature is 140°C-160°C.

[0105] In some embodiments, for the second reaction, the molar ratio of 4-methoxyaniline to 4-bromobenzyl sulfide is 1:1.

[0106] In some embodiments, the molar ratio of 4-methoxyaniline to the first base is 1:(1.2-1.5); for example, it can be a range of values ​​consisting of one or any two of 1:1.2, 1:1.3, 1:1.4, 1:1.5.

[0107] In some embodiments, the molar ratio of 4-methoxyaniline to the first catalyst is 1:(0.02-0.05); for example, it can be a range of one or any two of 1:0.02, 1:0.03, 1:0.04, 1:0.05.

[0108] In some embodiments, the molar ratio of 4-methoxyaniline to the first ligand is 1:(0.04-0.10); for example, it can be a range of one or any two of 1:0.04, 1:0.06, 1:0.08, 1:0.10.

[0109] In some embodiments, the second solvent includes at least one of toluene, xylene, 1,4-dioxane, 2-methyltetrahydrofuran, N,N-dimethylformamide, and dimethyl sulfoxide.

[0110] In some embodiments, the first base includes at least one of cesium carbonate, potassium carbonate, potassium phosphate, sodium tert-butoxide, potassium tert-butoxide, sodium ethoxide, potassium triisopropoxide, and potassium tritert-butoxyaluminum.

[0111] In some embodiments, the first catalyst comprises at least one of tris(dibenzylacetone)palladium(0), 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, palladium acetate, and bis(tri-tert-butylphosphine)palladium(0).

[0112] In some embodiments, the first ligand comprises at least one of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (X-Phos), 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl, 1,1'-bis(diphenylphosphine)ferrocene, tri-tert-butylphosphine, and boron tetrafluoride tritert-tert-butylphosphine.

[0113] In some implementations, the second reaction temperature is 60-80°C.

[0114] In some embodiments, for the third reaction, the molar ratio of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] and 4-methoxy-4'-methylthiodiphenylamine is 1:(4-4.4); for example, it can be a range of values ​​consisting of one or any two of 1:4, 1:4.1, 1:4.2, 1:4.3, 1:4.4.

[0115] In some embodiments, the molar ratio of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] to the second base is 1:(4.8-6.0); for example, it can be a range of values ​​consisting of one or any two of 1:4.8, 1:5.0, 1:5.2, 1:5.5, 1:6.0.

[0116] In some embodiments, the molar ratio of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] to the second catalyst is 1:(0.02-0.08); for example, it can be a range of one or any combination of 1:0.02, 1:0.04, 1:0.06, 1:0.08.

[0117] In some embodiments, the molar ratio of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] to the second ligand is 1:(0.04-0.16); for example, it can be a range of values ​​consisting of one or any two of 1:0.04, 1:0.08, 1:0.12, 1:0.16.

[0118] In some embodiments, the third solvent includes at least one of toluene, xylene, 1,4-dioxane, 2-methyltetrahydrofuran, N,N-dimethylformamide, and dimethyl sulfoxide.

[0119] In some embodiments, the second base includes at least one of sodium tert-butoxide, potassium tert-butoxide, sodium ethoxide, potassium triisopropoxide, and potassium tritert-butoxyaluminum.

[0120] In some embodiments, the second catalyst comprises at least one of tris(dibenzylacetone)palladium(0), 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, palladium acetate, and bis(tri-tert-butylphosphine)palladium(0).

[0121] In some embodiments, the second ligand comprises at least one of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (X-Phos), 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl, 1,1'-bis(diphenylphosphine)ferrocene, tri-tert-butylphosphine, and boron tetrafluoride tritert-tert-butylphosphine.

[0122] In some embodiments, the third reaction temperature is 90°C-120°C.

[0123] Specifically, this application does not specify the amount of the second and third solvents; the amounts of solvents used in chemical reactions that are well known to those skilled in the art can be used.

[0124] In some implementations, the first reaction time is 12-24 h. For example, it can be a range of 12 h, 16 h, 20 h, 24 h, or any combination of both.

[0125] In some implementations, the second reaction time is 6-14 h; for example, it can be a range of one or any combination of 6 h, 8 h, 10 h, 12 h.

[0126] In some implementations, the third reaction time is 12-24 h; for example, it can be a range of one or any combination of 12 h, 16 h, 20 h, 24 h.

[0127] In some implementations, the product obtained from the first reaction is washed and filtered with ice, a poor solvent.

[0128] In this application, the rinsing and filtration method is a method well known to those skilled in the art.

[0129] In some embodiments, the undesirable solvent includes at least one of methanol, ethanol, n-propanol, isopropanol, acetonitrile, and acetone.

[0130] In some implementations, the product obtained from the second reaction is subjected to a first extraction and a first column chromatography separation in sequence.

[0131] In this application, the extraction and column chromatography separation are methods well known to those skilled in the art.

[0132] Specifically, the reagents used in the first extraction were dichloromethane and deionized water, with a volume ratio of 1:1.

[0133] Specifically, the parameters for the first column chromatography separation include: the chromatographic column is an acidic silica gel column, the eluent is dichloromethane and petroleum ether, the elution method is gradient elution, and the elution polarity variation range is from pure CH2Cl2 / PE=1:10 to CH2Cl2 / PE=1:2 (v / v).

[0134] In some embodiments, the product obtained from the third reaction is subjected to a second extraction, diatomaceous earth filtration, and a first recrystallization in sequence.

[0135] In this application, the methods of second extraction, column chromatography separation, and recrystallization are well known to those skilled in the art.

[0136] Specifically, the reagents used in the second extraction are dichloromethane and deionized water, with a volume ratio of 1:1.

[0137] Specifically, the parameters for diatomaceous earth filtration include: the diatomaceous earth is alkaline, and the rinsing solvent is dichloromethane.

[0138] Specifically, the reagent used for recrystallization was ethyl acetate. The crude product was dissolved by heating ethyl acetate to 75°C, and crystals were precipitated in a -20°C refrigerator. The product was then obtained by filtration.

[0139] Unless otherwise specified in this application, the above-mentioned raw materials are preferably commercially available products known to those skilled in the art or prepared using methods known to those skilled in the art.

[0140] In some embodiments, when the hole transport material in the hole transport layer also includes other hole transport materials, materials commonly used in the art for hole transport layers can be selected. This application does not limit the types of these materials, such as one or more of the following materials and their derivatives, including but not limited to: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (abbreviated as: PTAA), 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (abbreviated as: Spiro-OMe). Materials that can transport holes and block electrons include TAD, poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS), poly3-hexylthiophene (P3HT), triphenylamine with a triphenylene core (H101), 3,4-ethylenedioxythiazole-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobisfluorene (CzPAF-SBF), polythiazole, triphenylamine monomers and their polymers, carbazole monomers and their polymers, etc.

[0141] In some embodiments, the first electrode can be made of various commonly used electrode materials in the art, such as any one or more composite materials of conductive oxides and conductive metals. Further, the conductive oxide includes at least one of FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), and IWO (tungsten-doped indium oxide); the conductive metal includes at least one of gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), and chromium (Cr).

[0142] In some embodiments, the electron transport material of the electron transport layer of this application is a common electron transport layer material in the art, and this application does not limit its type, such as at least one of tin oxide, titanium oxide and zinc oxide.

[0143] In some embodiments, the perovskite active material in the perovskite layer of this application is a common perovskite active material in the art. This application does not limit its type, such as FAxMAyCs(1-xy)Pb(IzBr(1-z))3 (often simply referred to as FAMACs), 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1; 0 ≤ z ≤ 1.

[0144] In some embodiments, the perovskite solar cell further includes a passivation layer disposed between the perovskite layer and the hole transport layer.

[0145] The passivation layer can be composed of commonly used passivation materials in the art, such as 2-cyclohexylethylammonium iodide, etc., and this application does not impose any special limitations on it.

[0146] In some embodiments, the perovskite solar cell of this application may be prepared using commonly used methods in the art, and this application does not limit this to such methods, for example, step S2 as follows.

[0147] Step S2: An electron transport layer, a perovskite layer, a hole transport layer, and a second electrode are sequentially formed on one side of the first electrode to obtain a perovskite solar cell.

[0148] In some embodiments, the methods for forming the perovskite layer, hole transport layer, and electron transport layer may also employ conventional methods in the art, and this application does not impose any particular limitation on them, including but not limited to: any one of spin coating, blade coating, and slot coating.

[0149] The specific preparation process can be referred to as follows, but is not limited to the following preparation methods.

[0150] In some embodiments, the perovskite layer preparation steps include: mixing preparation raw materials, such as cesium iodide (CsI), lead iodide (PbI2), methylammonium chloride (MACl), formamidinium hydroiodate (FAI), and an organic solvent to obtain a precursor solution.

[0151] In some embodiments, the organic solvent is N,N Dimethylformamide (DMF) and N-methylpyrrolidone (NMP).

[0152] In some embodiments, the hole transport layer preparation step includes: dissolving the hole transport material (Spiro-FX) in an ultra-dry solvent under an inert gas atmosphere, adding an oxide dopant (onium salt) and mixing and oxidizing to obtain a precursor solution for the hole transport layer; and spin-coating or blade-coating the precursor solution onto the surface of the perovskite layer to form the hole transport layer.

[0153] In some embodiments, the ultra-dry solvent includes at least one of chlorobenzene, dichlorobenzene, toluene, xylene, anisole, 2-methylanisole, 2-methyltetrahydrofuran, and chloroform.

[0154] In some embodiments, the time for mixed oxidation is 6-24 h; for example, it can be a range of one or any combination of 6h, 10h, 16h, 20h, 24h.

[0155] In some of these embodiments, the perovskite solar cell is a nip structure.

[0156] According to one embodiment of this application, a photovoltaic module is provided, the photovoltaic module including the perovskite cell as described above.

[0157] The photovoltaic module of this application, by employing the perovskite cell of this application, has high photoelectric conversion efficiency and good stability.

[0158] In some embodiments, the photovoltaic module is a solar panel.

[0159] The present application will be described below with reference to specific embodiments, but the present application is not limited to the following embodiments. It should be understood that the appended claims summarize the scope of the present application. Under the guidance of the concept of the present application, those skilled in the art should realize that certain changes made to the various embodiments of the present application will be covered by the spirit and scope of the claims of the present application.

[0160] The following are specific examples.

[0161] The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0162] Example 1 The synthetic route for preparing compound Spiro-FX is as follows:

[0163] (1) Preparation of 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxanthracene] Under a nitrogen atmosphere, 100 mmol of 2,7-dibromo-9H-fluorene-9-one, 500 mmol of 3-bromophenol, and 500 mmol of methanesulfonic acid were added to a 1 L Schlenk flask. After purging with nitrogen for 15 min, the mixture was reacted at 140 °C for 12 h. The reaction was monitored by TLC until the reaction was complete, and the first reactant was obtained. The mixture was cooled to room temperature, and the reaction was quenched by adding 1 L of ice-cold ethanol. The mixture was then filtered to obtain 61.4 g of a pale pink solid, which was 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthracene] (yield 94.81%).

[0164] (2) Preparation of 4-methoxy-4'-methylthiodiphenylamine Under a nitrogen atmosphere, 100 mmol of 4-methoxyaniline, 100 mmol of 4-bromobenzyl sulfide, 2 mmol of tris(dibenzylacetone)palladium, 5 mmol of X-Phos, and 150 mmol of sodium tert-butoxide were added to a 500 mL Schlenk flask. The nitrogen atmosphere was purged three times, and 100 mL of toluene was added. After stirring, the mixture was reacted at 80 °C for 8 h. The reaction was monitored by TLC until the reaction was complete, yielding the second reactant. The second reactant was extracted three times with dichloromethane / deionized water, and the organic phase was collected. The organic phase was dried with anhydrous sodium sulfate, and the solid was removed by filtration. The mixture was concentrated by rotary evaporation and purified by silica gel column chromatography using dichloromethane / petroleum ether at a ratio of 1:10 to 1:2 (v / v) to obtain 21.3 g of white solid, which was 4-methoxy-4'-methylthiodiphenylamine (yield 86.83%).

[0165] (3) Preparation of Spiro-FX Under a nitrogen atmosphere, 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] (10 mmol), 4-methoxy-4'-methylthiodiphenylamine (44 mmol), tris(dibenzylacetone)dipalladium (0.4 mmol), X-Phos (12 mmol), and sodium tert-butoxide (52 mmol) were added to a 250 mL Schlenk flask. The nitrogen atmosphere was purged three times, and 50 mL of toluene was added. After stirring, the mixture was reacted at 110 °C for 15 h. The reaction was monitored by TLC until it ended, yielding the third reactant. The third reactant was extracted three times with dichloromethane / deionized water, and the organic phase was collected. The organic phase was dried with anhydrous sodium sulfate, filtered through diatomaceous earth to remove the solid, and the filter cake was washed with dichloromethane. The organic phase was collected, the solvent was evaporated, and 50 mL of ethyl acetate was added for recrystallization once to obtain 8.54 g of yellowish-white solid, which was Spiro-FX (yield 68.16%).

[0166] 20 mg of Spiro-FX was dissolved in deuterated dichloromethane and characterized by proton NMR spectroscopy. The NMR spectrum is shown below. Figure 1 As shown.

[0167] Example 2 Example 2 is basically the same as Example 1, except for the following step (3): (3) Preparation of Spiro-FX Under a nitrogen atmosphere, 2',2',7',7'-tetrabromospiro[fluorene-9,9'-oxazanthene] (15 mmol), 4-methoxy-4'-methylthiodiphenylamine (68 mmol), palladium acetate (0.7 mmol), Ru-Phos (14 mmol), and potassium tert-butoxide (72 mmol) were added to a 250 mL Schlenk flask. The nitrogen atmosphere was purged three times, and 50 mL of o-xylene was added. After stirring, the mixture was reacted at 110 °C for 12 h. The reaction was monitored by TLC until it ended, and the reactants were obtained. The reactants were extracted three times with dichloromethane / deionized water, and the organic phase was collected. The organic phase was dried with anhydrous sodium sulfate, filtered through diatomaceous earth to remove the solid, and the filter cake was washed with dichloromethane. The organic phase was collected, the solvent was evaporated, and the mixture was recrystallized once with 75 mL of ethyl acetate to obtain 11.98 g of pale yellow solid, which was Spiro-FX (yield 63.76%).

[0168] Example 3 (1) Preparation of bis(4-tert-butylphenyl)iodonium p-toluenesulfonate Under a nitrogen atmosphere, 30 mmol of 4-tert-butyliodobenzene and 66 mmol of tert-butylbenzene were added to a 250 mL Schlenk flask. 40 mL of anhydrous dichloromethane was added and stirred until dissolved. Then, 33 mmol of m-chloroperoxybenzoic acid (mCPBA) was slowly added using a solid feeding funnel. After the addition was complete and the mixture was stirred for 15 min, 90 mmol of p-toluenesulfonic acid monohydrate was slowly added using a solid feeding funnel. The reaction was carried out at 35 °C for 7 hours. The reaction mixture was collected by TLC and extracted three times with ethyl acetate / deionized water. The organic phase was collected, dried over anhydrous sodium sulfate, and the insoluble matter was filtered off. After rotary evaporation, 30 mL of acetonitrile was added, and the mixture was sonicated for 15 min. The mixture was then cooled in a refrigerator. The next day, a white solid precipitated. 15.03 g of the white solid obtained by filtration was bis(4-tert-butylphenyl)iodomonium p-toluenesulfonate (yield 90.72%). The synthetic route is as follows:

[0169] (2) Preparation of bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt Under a nitrogen atmosphere, 20 mmol of bis(4-tert-butylphenyl)iodonium p-toluenesulfonate and 20 mmol of lithium bis(trifluoromethanesulfonyl)imide were added to a 250 mL Schlenk flask. 30 mL of anhydrous dichloromethane was added and stirred. After ion exchange for 4 h, the lithium p-toluenesulfonate solid was removed by filtration. The organic phase was collected and chromatographically examined with a neutral alumina solution of dichloromethane / methanol (10:1). 11.43 g of a white solid, bis(4-tert-butylphenyl)iodonium p-toluenesulfonyl)imide (yield 86.62%), was obtained, with the following structure:

[0170] 30 mg of bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt was dissolved in DMSO-d6 and characterized by 1H NMR spectroscopy. The NMR spectrum is shown below. Figure 2 As shown.

[0171] Example 4 (1) Preparation of (4-methoxyphenyl)(trimethylmethyl)iodonium trifluoromethanesulfonate Under a nitrogen atmosphere, 50 mmol of 4-methoxyphenyliodobenzene and 120 mmol of mesitylene were added to a 250 mL Schlenk flask. 80 mL of anhydrous ethyl acetate was added and stirred to dissolve the precipitate. Then, 55 mmol of m-chloroperoxybenzoic acid was slowly added using a solid feeding funnel. After the addition was complete, the mixture was stirred for 15 min and pre-cooled at -10°C for 30 min. Trifluoromethanesulfonic acid (160 mmol) was slowly added using a constant pressure dropping funnel. The mixture was reacted at 60°C for 3 hours. The reaction was monitored by TLC until it was complete, and the reactants were obtained. The reactants were extracted three times with ethyl acetate / deionized water. The organic phase was collected, dried over anhydrous sodium sulfate, and the insoluble matter was filtered off. After the organic phase was evaporated to dryness, 80 mL of acetonitrile was added and sonicated for 15 min. The mixture was then cooled in a refrigerator. The next day, a white solid precipitated. 20.62 g of the white solid obtained by filtration was (4-methoxyphenyl)(mesitylene)iodonium trifluoromethanesulfonate (yield 84.13%). The synthesis route is as follows:

[0172] (2) Preparation of (4-methoxyphenyl)(trimethylmethyl)bis(trifluoromethanesulfonyl)imine salt Under a nitrogen atmosphere, 20 mmol of (4-methoxyphenyl)(trimethylyl)iodonium trifluoromethanesulfonate and 20 mmol of sodium bis(trifluoromethanesulfonyl)imide were added to a 250 mL Schlenk flask. 30 mL of anhydrous acetonitrile was added and the mixture was stirred. After ion exchange for 4 h, the sodium trifluoromethanesulfonate solid was removed by filtration. The organic phase was collected and chromatographically examined with dichloromethane / methanol (10:1) at a neutral alumina concentration to obtain 11.18 g of a white solid, which was (4-methoxyphenyl)(trimethylyl)bis(trifluoromethanesulfonyl)imide (yield 90.14%). The structure is as follows:

[0173] 30 mg of (4-methoxyphenyl)(trimethylmethyl)iodonium bis(trifluoromethanesulfonyl)imide salt was dissolved in DMSO-d6 and characterized by 1H NMR spectroscopy. The NMR spectrum is shown below. Figure 3 As shown.

[0174] Example 5 (1) Preparation of bis(4-methoxyphenyl)iodonium methane sulfonate Under a nitrogen atmosphere, 50 mmol of 4-methoxyiodobenzene and 120 mmol of anisole were added to a 250 mL Schlenk flask. 80 mL of anhydrous acetonitrile was added and stirred until dissolved. Then, 55 mmol of m-chloroperoxybenzoic acid was slowly added using a solid feeding funnel. After addition, the mixture was stirred for 15 min and pre-cooled at -10°C for 30 min. 150 mmol of methanesulfonic acid was then slowly added using a constant-pressure dropping funnel. The reaction was carried out at 70°C for 3 hours. The reaction was monitored by TLC until completion, yielding the reactants. The reactants were extracted three times with ethyl acetate / deionized water. The organic phase was collected, dried over anhydrous sodium sulfate, and the insoluble matter was filtered off. After rotary evaporation, 80 mL of acetonitrile was added, and the mixture was sonicated for 15 min. The mixture was then cooled in a refrigerator. The next day, a white solid precipitated. 20.02 g of the white solid obtained by filtration was di(4-methoxyphenyl)iodomonium methanesulfonate (yield 91.86%). The synthetic route is as follows:

[0175] (2) Preparation of bis(4-methoxyphenyl)iodonium bis(trifluoromethanesulfonyl)imine salt Under a nitrogen atmosphere, 20 mmol of bis(4-methoxyphenyl)iodonium methanesulfonate and 20 mmol of potassium bis(trifluoromethanesulfonyl)imide were added to a 250 mL Schlenk flask. 30 mL of anhydrous toluene was added and stirred. After ion exchange for 4 h, the potassium methanesulfonate solid was removed by filtration. The organic phase was collected and chromatographically examined with dichloromethane / methanol at a ratio of 10:1 using neutral alumina chromatography to obtain 10.95 g of a white solid, which was bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide (yield 88.16%), with the following structure:

[0176] 30 mg of bis(4-methoxyphenyl)iodonium iodonium bis(trifluoromethanesulfonyl)imide salt was dissolved in DMSO-d6 and characterized by 1H NMR spectroscopy. The NMR spectrum is shown below. Figure 4 As shown.

[0177] Example 6 Preparation of (1) (4-methylphenyl)(2-thienyl)iodonium camphor sulfonate Under a nitrogen atmosphere, 50 mmol of 4-methyliodobenzene and 120 mmol of thiophene were added to a 250 mL Schlenk flask. 80 mL of anhydrous chloroform was added and stirred until dissolved. Then, 55 mmol of m-chloroperoxybenzoic acid was slowly added using a solid feeding funnel. After addition, the mixture was stirred for 15 min and pre-cooled at -10°C for 30 min. 150 mmol of camphorsulfonic acid was then slowly added using a constant-pressure dropping funnel. The reaction was carried out at 50°C for 6 hours. The reaction was monitored by TLC until completion, and the reactants were obtained. The reactants were extracted three times with ethyl acetate / deionized water. The organic phase was collected, dried over anhydrous sodium sulfate, and the insoluble matter was filtered off. After rotary evaporation, 80 mL of acetonitrile was added, and the mixture was sonicated for 15 min. The mixture was then cooled in a refrigerator. The next day, a white solid precipitated. 23.32 g of the white solid obtained by filtration was (4-methylphenyl)(2-thienyl)iodonium camphorsulfonate (yield 87.69%). The synthetic route is as follows:

[0178] (2) Preparation of (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt Under a nitrogen atmosphere, 20 mmol of (4-methylphenyl)(2-thienyl)iodonium trifluoromethanesulfonate and 20 mmol of bis(trifluoromethanesulfonyl)imide silver were added to a 250 mL Schlenk flask. 30 mL of anhydrous toluene was added and stirred. After ion exchange for 4 h, the camphorsulfonate solid was removed by filtration. The organic phase was collected and subjected to neutral alumina chromatography with dichloromethane / methanol = 10:1 to obtain 9.29 g of white solid, which was (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt (yield 83.40%), with the following structure.

[0179]

[0180] 30 mg of (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt was dissolved in DMSO-d6 and characterized by 1H NMR spectroscopy. The NMR spectrum is shown below. Figure 5 As shown.

[0181] Example 7 Preparation of hole transport precursor oxidation solution: (1) In a glove box, 313.4 mg (0.25 mmol, molecular weight 1253.6) of Spiro-FX prepared in Example 1 was weighed and dissolved in 5 mL of chlorobenzene (water content <50 ppm), and then 50.5 mg (0.075 mmol, molecular weight 673.2) of bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 3 was added and the mixture was shaken and oxidized for 12 h to obtain hole transport precursor oxidation solution A.

[0182] Hole transport precursor oxidation solution A physical samples before and after oxidation, for example... Figure 6 As shown.

[0183] (2) In a glove box, 313.4 mg (0.25 mmol) of Spiro-FX prepared in Example 1 was weighed and dissolved in 5 mL of chlorobenzene. Then, 47.5 mg (0.075 mmol, molecular weight 633.2) of (4-methoxyphenyl) (trimethylmethyl) bis(trifluoromethanesulfonyl) imine salt prepared in Example 4 was added and oxidized by shaking for 12 h to obtain hole transport precursor oxidation solution B.

[0184] (3) In a glove box, 313.4 mg (0.25 mmol) of Spiro-FX prepared in Example 1 was weighed and dissolved in 5 mL of chlorobenzene. Then, 46.6 mg (0.075 mmol, molecular weight 621.3) of bis(4-methoxyphenyl)iodonium iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 5 was added and oxidized by shaking for 12 h to obtain hole transport precursor oxidation solution C.

[0185] (4) In a glove box, 313.4 mg (0.25 mmol) of Spiro-FX prepared in Example 1 was weighed and dissolved in 5 mL of chlorobenzene. Then, 43.6 mg (0.075 mmol, molecular weight 581.3) of (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 6 was added and oxidized by shaking for 12 h to obtain hole transport precursor oxidation solution D.

[0186] Application Example 1 The specific steps for fabricating a formal nip structure single-junction perovskite solar cell are as follows: (1) Preparation of FTO glass substrate: The FTO glass substrate was ultrasonically cleaned with deionized water, isopropanol, acetone and ethanol for 20 min respectively, and then cleaned with ultraviolet ozone for 30 min to obtain pretreated FTO glass substrate.

[0187] (2) Preparation of electron transport layer: The tin oxide layer was prepared by chemical bath deposition. 5g of urea was dissolved in 350 mL of deionized water, 5 mL of concentrated hydrochloric acid was slowly added, followed by 100 μL of mercaptoacetic acid. After stirring evenly, 1.096 g of stannous chloride dihydrate was weighed and stirred until the solution was clear and transparent. FTO was vertically immersed in the solution and deposited at 90°C in the dark for 3 hours. Finally, it was sonicated 3 times with deionized water for 2 minutes each time, and then sonicated 2 times with isopropanol for 5 minutes each time. The FTO glass with deposited tin oxide was dried with a nitrogen gun to form the electron transport layer.

[0188] (3) Preparation of perovskite layer: In a one-step method, a 2M perovskite precursor solution was spin-coated on the surface of the electron transport layer at 5000 rpm for 60s in a glove box, annealed at 70℃ for 1min in a glove box, and then annealed at 150℃ in an air environment with 20-30%RH to obtain the perovskite layer.

[0189] (4) Preparation of passivation layer: 1 mg / mL of ethyl acetate solution of 2-cyclohexylethylammonium iodide was spin-coated on the surface of the perovskite layer for 30 s at a speed of 5000 rpm to form an interface passivation layer.

[0190] (5) Preparation of hole transport layer: The hole transport precursor oxidation solution A in Example 7 was spin-coated on the surface of the passivation layer at 3000 rpm for 30 s, and then dried to form a hole transport layer.

[0191] (6) Fabrication of the metal electrode: at 5.5 × 10 -4 Under Pa conditions, gold with a thickness of 80 nm was deposited on the surface of the hole transport layer as an electrode to obtain a formal nip structure single-junction perovskite solar cell.

[0192] Application Example 2 Application Example 2 is basically the same as Application Example 1, except for the following steps: (5) Preparation of hole transport layer: The hole transport precursor oxidation solution B in Example 7 was spin-coated on the surface of the passivation layer at 3000 rpm for 30 s, and then dried to form a hole transport layer.

[0193] The other steps and conditions are the same as in Application Example 1.

[0194] Application Example 3 Application Example 3 is basically the same as Application Example 1, except for the following steps: (5) Preparation of hole transport layer: The hole transport precursor oxidation solution C in Example 7 was spin-coated on the surface of the passivation layer at 3000 rpm for 30 s, and then dried to form a hole transport layer.

[0195] The other steps and conditions are the same as in Application Example 1.

[0196] Application Example 4 Application Example 4 is basically the same as Application Example 1, except for the following steps: (5) Preparation of hole transport layer: The hole transport precursor oxidation solution D in Example 7 was spin-coated on the surface of the passivation layer at 3000 rpm for 30 s, and then dried to form a hole transport layer.

[0197] The other steps and conditions are the same as in Application Example 1.

[0198] Application Example 5 Application Example 5 is basically the same as Application Example 1, except for the following steps: (5) Preparation of the hole transport layer: 306.4 mg (0.25 mmol) of Spiro-OMeTAD was dissolved in 5 mL of anhydrous chlorobenzene, and 50.5 mg (0.075 mmol) of bis(4-tert-butylphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 3 was added. The mixture was shaken and oxidized for 12 h to obtain a precursor solution of Spiro-OMeTAD. The Spiro-OMeTAD precursor solution was spin-coated onto the surface of the perovskite passivation layer at 3000 rpm for 30 s to form a hole transport layer.

[0199] The remaining steps and conditions are the same as in Application Example 1.

[0200] Application Example 6 Application Example 6 is basically the same as Application Example 1, except for the following steps: (5) Preparation of the hole transport layer: 306.4 mg (0.25 mmol) of Spiro-OMeTAD was dissolved in 5 mL of anhydrous chlorobenzene, and 47.5 mg (0.075 mmol) of (4-methoxyphenyl)(trimethylyl)bis(trifluoromethanesulfonyl)imide salt prepared in Example 4 was added. The mixture was shaken and oxidized for 12 h to obtain a precursor solution of Spiro-OMeTAD. The Spiro-OMeTAD precursor solution was spin-coated onto the surface of the perovskite passivation layer at 3000 rpm for 30 s to form a hole transport layer.

[0201] The remaining steps and conditions are the same as in Application Example 1.

[0202] Application Example 7 Application Example 7 is basically the same as Application Example 1, except for the following steps: (5) Preparation of the hole transport layer: 306.4 mg (0.25 mmol) of Spiro-OMeTAD was dissolved in 5 mL of anhydrous chlorobenzene, and 47.5 mg (0.075 mmol) of bis(4-methoxyphenyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 5 was added. The mixture was shaken and oxidized for 12 h to obtain a precursor solution of Spiro-OMeTAD. The Spiro-OMeTAD precursor solution was spin-coated onto the surface of the perovskite passivation layer at 3000 rpm for 30 s to form a hole transport layer.

[0203] The remaining steps and conditions are the same as in Application Example 1.

[0204] Application Example 8 Application Example 8 is basically the same as Application Example 1, except for the following steps: (5) Preparation of the hole transport layer: 306.4 mg (0.25 mmol) of Spiro-OMeTAD was dissolved in 5 mL of anhydrous chlorobenzene, and 47.5 mg (0.075 mmol) of (4-methylphenyl)(2-thienyl)iodonium bis(trifluoromethanesulfonyl)imide salt prepared in Example 6 was added. The mixture was shaken and oxidized for 12 h to obtain a precursor solution of Spiro-OMeTAD. The Spiro-OMeTAD precursor solution was spin-coated onto the surface of the perovskite passivation layer at 3000 rpm for 30 s to form a hole transport layer.

[0205] The remaining steps and conditions are the same as in Application Example 1.

[0206] Comparative Application Example 1 The comparison with Application Example 1 is basically the same, except for the following steps: (5) Preparation of hole transport layer: Prepare a 520 mg / mL LiTFSI acetonitrile solution for later use. Weigh 306.4 mg of Spiro-OMeTAD (0.25 mmol, molecular weight 1225.43) and dissolve it in 5 mL of anhydrous chlorobenzene. Add 120.6 μL (0.755 mmol) of tert-butylpyridine and 73.9 μL of the 520 mg / mL LiTFSI acetonitrile solution. Stir and oxidize at room temperature for 12 h to prepare a Spiro-OMeTAD precursor solution. Spin-coat the surface of the passivation layer with the Spiro-OMeTAD precursor solution at 3000 rpm for 30 s to form a hole transport layer.

[0207] The other steps and conditions are the same as in Application Example 1.

[0208] Comparative Application Example 2 Compare Application Example 2 with Application Example 1. The difference lies only in the following steps: (5) Preparation of hole transport layer: Prepare a 520 mg / mL LiTFSI acetonitrile solution for later use. Weigh 313.4 mg (0.25 mmol, molecular weight 1225.43) of Spiro-FX prepared in Example 1 and dissolve it in 5 mL of anhydrous chlorobenzene. Add 120.6 μL (0.755 mmol) of tert-butylpyridine and 73.9 μL of 520 mg / mL LiTFSI acetonitrile solution. Stir and oxidize at room temperature for 12 h to prepare a Spiro-OMeTAD precursor solution. Spin-coat the Spiro-OMeTAD precursor solution on the surface of the perovskite passivation layer at 3000 rpm for 30 s to form a hole transport layer.

[0209] The remaining steps and conditions are the same as in Application Example 1.

[0210] test (1) Under standard test conditions (AM 1.5G illumination), the JV characteristics of the perovskite solar cells obtained in Examples 1-8 and Comparative Application Examples 1-2 were tested. Each group of perovskite solar cells consisted of 20 cells, and the effective area of ​​each perovskite solar cell was 0.15 cm². 2 The test results are averaged, as shown in Table 1.

[0211] (2) The T90 test results are based on the steady-state power output at the maximum power output point voltage. The equipment is an industrial customized version, using an LED solar simulator based on AM 1.5G and 100mW / cm². 2 Light intensity, nitrogen atmosphere; T90 refers to the time required for the photoelectric conversion efficiency of the perovskite solar cell to decrease to 90% of its initial efficiency. The test results are shown in Table 1.

[0212] Table 1

[0213] Note: Voc: Open-circuit voltage; Jsc: Short-circuit current density; FF: Fill factor; PCE: Photoelectric conversion efficiency; Comparative analysis of the data in Table 1 shows that, when comparing the data of Application Examples 1-8 with those of Comparative Application Examples 1-2, the photoelectric efficiency and stability of the devices in Application Examples 1-8 are far superior to those in Comparative Application Examples 1-2. This indicates that when the onium salt of the present invention is used as an oxide dopant in the preparation of perovskite solar cells, especially when it is used to prepare the hole transport layer, there is no lithium volatilization. It can eliminate lithium ion lattice penetration, reduce the probability of ion erosion, interface defects, and component volatilization in the hole transport layer, and achieve high photoelectric conversion efficiency and excellent long-term stability under humid heat.

[0214] Furthermore, by comparing Application Examples 1 and 5, Application Examples 2 and 6, Application Examples 3 and 7, and Application Examples 4 and 8 in pairs, the photoelectric efficiency and stability of the perovskite solar cells obtained by combining the conventional transport material piro-OMeTAD with the onium salt of this application in Application Examples 5-8 were further improved compared to Application Examples 1-4, which used the transport material Spiro-FX with a specific structure with the onium salt of this application.

[0215] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0216] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A kind of onium salt, characterized in that, The structure of the onium salt is shown in formula (A): ， Among them, Ar 1 and Ar 2 Each is independently selected from: any one of the following: aryl groups with 6-30 substituted or unsubstituted ring atoms, and heteroaryl groups with 5-30 substituted or unsubstituted ring atoms; "Represents Ar" 1 and Ar 2 It may or may not form a ring with iodide ions.

2. The onium salt as described in claim 1, characterized in that, The onium salt includes at least one of formula (A-1) and formula (A-2): ； In equation (A-2) Representative: Ar 1 and Ar 2 It fuses with iodide ions to form a ring.

3. The onium salt as described in claim 1 or 2, characterized in that, The Ar 1 and Ar 2 Each is independently selected from any one of the following: an aryl group with 6-15 unsubstituted ring atoms, an aryl group with 6-15 ring atoms substituted by a first substituent, a heteroaryl group with 5-15 unsubstituted ring atoms, and a heteroaryl group with 5-15 ring atoms substituted by a second substituent; The first substituent and the second substituent are each independently selected from any one of the following: alkyl groups having 1-7 carbon atoms, alkoxy groups having 1-7 carbon atoms, nitro groups, amino groups, halogen groups, aryl groups having 6-10 ring atoms, substituted or unsubstituted aryloxy groups having 6-10 ring atoms, substituted or unsubstituted heteroaryloxy groups having 5-10 ring atoms, and heteroaryl groups having 5-10 ring atoms.

4. The onium salt as described in claim 1 or 2, characterized in that, The aryl group is selected from any one of: phenyl, naphthyl, indene, benzocyclopentyl; and / or The heteroaryl group is selected from any one of pyridyl, thienyl, thiazolyl, imidazolyl, and quinolinyl.

5. The onium salt as described in claim 1 or 2, characterized in that, The onium salt includes at least one of the following structures: 。 6. The method for preparing onium salt according to any one of claims 1 to 5, characterized in that, Includes the following steps: The compound of formula (a) was subjected to an exchange reaction with a bis(trifluoromethanesulfonyl)imide salt to obtain the onium salt shown in formula (A): ； Among them, X - It represents the anion of the acid radical.

7. The method for preparing onium salts as described in claim 6, characterized in that, The molar ratio of the compound of formula (a) to the bis(trifluoromethanesulfonyl)imide salt is (0.8~1.2):1; and / or The bis(trifluoromethanesulfonyl)imide salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, and calcium bis(trifluoromethanesulfonyl)imide.

8. The use of the onium salt as an oxide dopant as described in any one of claims 1 to 5.

9. The application as described in claim 8, characterized in that, The application refers to the use of the onium salt as an oxide dopant in the preparation of the hole transport layer of a perovskite solar cell.

10. A hole transport composition, characterized in that, The hole transport composition includes a hole transport material and an oxide dopant, wherein the oxide dopant includes a bellium salt as described in any one of claims 1 to 5.

11. The hole transport composition of claim 10, characterized in that, Based on the total mass of the hole transport composition, the oxide dopant accounts for 2%-25%; and / or The hole transport material comprises the compound shown in formula (B) below: （B）。 12. A perovskite battery, characterized in that, The perovskite solar cell comprises: an onium salt as described in any one of claims 1 to 5 or a hole transport composition as described in claim 10 or 11.

13. The perovskite solar cell as described in claim 12, characterized in that, The perovskite solar cell comprises, in sequence, a first electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a second electrode, wherein the hole transport layer comprises the onium salt or the hole transport composition.

14. The perovskite solar cell as described in claim 12 or 13, characterized in that, Based on the total mass of the hole transport layer, the mass percentage of the onium salt is 2% to 25%; and / or The hole transport layer further includes a hole transport material, which comprises a compound as shown in formula (B): （B）。 15. A photovoltaic module, characterized in that, The photovoltaic module includes a perovskite cell as described in any one of claims 12-14.

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