Self-assembled micromolecule and preparation method thereof, interface modification film and perovskite battery

Abstract

The invention discloses a self-assembled micromolecule, a preparation method thereof, an interface modification film and a perovskite battery, and belongs to the technical field of perovskite batteries. The self-assembled micromolecule designed and synthesized by the invention has a conjugate plane with relatively large extension and a D-A1-A2-D type molecular structure, and can be applied to a perovskite battery to solve the technical problem that interface energy level mismatch is easy to occur in the perovskite battery.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite batteries, and in particular to a self-assembling small molecule and a preparation method thereof, an interface modification film and a perovskite battery. Background Art

[0002] Using phenethylammonium bromide (PEAI) or its derivatives as passivators has become a conventional process for preparing high-efficiency perovskite cells. However, although PEAI and its derivatives have well passivated the upper surface of the perovskite active layer, there is still an energy level mismatch problem. PEAI will have an adverse effect on the interface energy level arrangement, which may lead to a negative work function shift, and then induce carrier accumulation at the upper interface of the perovskite active layer. In addition, the mismatch of the interface energy level is also prone to activate the migration of halide ions on the surface of the N-type perovskite film, thereby exacerbating the instability of the device. Therefore, it is necessary to seek a reasonable molecule that can optimize the interface energy level structure. Summary of the invention

[0003] The main purpose of the present invention is to provide a self-assembled small molecule and a preparation method, an interface modification film and a perovskite battery, so as to solve the technical problem that interface energy level mismatch is easy to occur in perovskite batteries.

[0004] To achieve the above object, the present invention provides a self-assembling small molecule, wherein the self-assembling small molecule has the following structural formula:

[0005]

[0006] The present invention also provides a method for preparing the self-assembling small molecule as described above, comprising the following steps:

[0007] Preparation of intermediate 2: adding intermediate 1, 4-boric acid ester-4',4'-dimethoxytriphenylamine and catalyst 2 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 2, washing and extracting reactant 2 to obtain extract 2, drying and purifying extract 2 to obtain intermediate 2, wherein intermediate 1 is 5,9-dibromo-7H-dibenzo[c,g]carbazole;

[0008] Preparation of intermediate 3: adding the intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating for reaction to obtain reactant 3, washing and extracting the reactant 3 to obtain extract 3, and drying and purifying the extract 3 to obtain intermediate 3;

[0009] Preparation of intermediate 4: adding the intermediate 3, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde and catalyst 4 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 4, washing and extracting the reactant 4 to obtain extract 4, and drying and purifying the extract 4 to obtain intermediate 4;

[0010] Preparation of intermediate 5: adding the intermediate 4 and 2-diethoxyphosphorylacetonitrile to a mixture of an alkaline organic solution, toluene and piperidine, heating and refluxing the mixture, and evaporating the solvent to obtain reactant 5; dissolving, washing and extracting the reactant 5 to obtain an organic phase; and drying, evaporating and purifying the organic phase to obtain intermediate 5;

[0011] Preparation of self-assembling small molecules: the intermediate 5 is dissolved in an organic solvent, and trimethyl alkyl bromide is added to react, and then the self-assembling small molecules are obtained through quenching reaction, removal of solvent, and recrystallization.

[0012] In some embodiments of the present invention, the structural formulas of intermediate 1, intermediate 2, intermediate 3, intermediate 4, and intermediate 5 are as follows:

[0013]

[0014]

[0015] In some embodiments of the present invention, in the step of preparing intermediate 2,

[0016] The molar ratio of the intermediate 1 to 4-boronate-4',4'-dimethoxytriphenylamine is 1:(2.5-3);

[0017] And / or, the catalyst 2 comprises tetrakistriphenylphosphine palladium;

[0018] and / or, the alkaline organic mixed aqueous solution comprises anhydrous potassium carbonate, water and tetrahydrofuran;

[0019] And / or, the temperature range of the heating reaction is 65°C to 85°C;

[0020] And / or, the reaction time of the heating reaction is 12h to 24h;

[0021] And / or, the extraction comprises an extraction liquid, and the extraction liquid comprises at least one of dichloromethane, ethyl acetate, and trichloroethane;

[0022] And / or, the purifying comprises column chromatography.

[0023] In some embodiments of the present invention, in the step of preparing intermediate 3:

[0024] The molar ratio of the intermediate 2 to 1,2-dibromobutane is 1:(15-30);

[0025] And / or, the catalyst 3 comprises tetrabutylammonium bromide;

[0026] And / or, the alkaline solvent includes an aqueous solution of potassium hydroxide and an aqueous solution of sodium hydroxide;

[0027] And / or, the temperature range of the heating reaction is 65°C to 85°C;

[0028] And / or, the reaction time of the heating reaction is 12h to 24h;

[0029] and / or, the extraction comprises an extraction liquid, and the extraction liquid comprises dichloromethane;

[0030] And / or, the purification comprises silica gel column chromatography purification.

[0031] In some embodiments of the present invention, in the step of preparing intermediate 4:

[0032] The molar ratio of the intermediate 3 to 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde is 1:(1.2-1.7);

[0033] And / or, the catalyst 4 comprises tetrakistriphenylphosphine palladium;

[0034] and / or, the molar content of the catalyst 4 is in the range of 0.08 mmol to 0.2 mmol;

[0035] And / or, the alkaline organic mixed aqueous solution comprises anhydrous potassium carbonate, water and tetrahydrofuran;

[0036] And / or, the temperature range of the heating reaction is 65°C to 85°C;

[0037] And / or, the reaction time of the heating reaction is 12h to 24h.

[0038] In some embodiments of the present invention, in the step of preparing intermediate 5:

[0039] and / or, the molar ratio of the intermediate 4 to 2-diethoxyphosphorylacetonitrile is 1:(12-30);

[0040] And / or, the alkaline organic solution comprises a mixed solution of toluene and piperidine or a mixed solution of toluene and pyridine;

[0041] And / or, the temperature range of the heating reflux reaction is 100° C. to 120° C.;

[0042] And / or, the reaction time of the heating reflux reaction is 8h to 12h.

[0043] In some implementations of the present invention, in the step of preparing the self-assembling small molecule:

[0044] The molar ratio of the intermediate 5 to trimethylbromethane is 1:(5-10);

[0045] and / or, completing the quenching reaction by adding methanol;

[0046] and / or, removing the solvent by adding methanol;

[0047] And / or, the recrystallization is completed by adding methanol to obtain the self-assembling small molecule.

[0048] The present invention also provides an interface modification film, which is applied to a perovskite battery and comprises the self-assembled small molecules as described above.

[0049] In some embodiments of the present invention, the interface modification film further comprises at least one of phenethylammonium bromide and its derivatives.

[0050] The present invention also provides a method for preparing the interface modification film as described above, comprising the following steps:

[0051] Dissolving the self-assembling small molecule and at least one of phenethylammonium bromide and its derivatives in an organic solvent to obtain an interface modification film precursor solution;

[0052] The interface modification film precursor solution is spin-coated onto the surface of the substrate to form an interface modification film.

[0053] In some embodiments of the present invention, the molar ratio of at least one of phenethylammonium bromide and its derivatives to the self-assembling small molecule is 1:(0.5-4).

[0054] The present invention also provides a perovskite battery, which comprises the interface modification film as described above.

[0055] In some embodiments of the present invention, the interface modification film is disposed on the surface of the perovskite active layer.

[0056] In some embodiments of the present invention, the perovskite cell includes a formal perovskite cell, which includes, from bottom to top, a front electrode layer, an electron transport layer, the perovskite active layer, an interface modification layer, a hole transport layer, and a back electrode layer;

[0057] Wherein, the interface modification layer includes the interface modification film.

[0058] The beneficial effects that can be achieved by the present invention are:

[0059] The self-assembling small molecule designed and synthesized by the present invention has a large extended conjugated plane and a D-A1-A2-D type molecular structure. This type of molecular structure enables the self-assembling small molecule to have a relatively matched energy level. At the same time, the triphenylamine units on both sides also enable the self-assembling small molecule to have helical flanks, which can reduce the unfavorable accumulation of the self-assembling small molecule, help solution processing and promote the extraction of holes.

[0060] The present invention applies self-assembled small molecules to perovskite batteries to prepare an interface modification film. The interface modification film can be used as a passivation layer of the perovskite device and is arranged on the surface of the perovskite active layer to improve the interface contact with the perovskite active layer, passivate the interface defects of the perovskite active layer and obtain a more suitable energy level, thereby promoting efficient and rapid hole extraction, and is also beneficial for the self-assembled molecules (SAM) to be fixed at the interface of the hole transport layer and the perovskite active layer, blocking the unfavorable lithium ion migration in the hole transport material, and improving the overall wet heat stability and structural stability of the perovskite battery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0062] Figure 1 This is a schematic diagram of the preparation process of self-assembled small molecules according to an embodiment of the present invention.

[0063] Figure 2 This is a comparison diagram of the current density-voltage curves of the perovskite battery devices prepared in Example 1 of the present invention and Comparative Example 1.

[0064] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0065] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0068] Using phenethylammonium bromide (PEAI) or its derivatives as passivators has become a conventional process for preparing high-efficiency perovskite cells. However, although PEAI and its derivatives have well passivated the upper surface of the perovskite active layer, there is still an energy level mismatch problem. PEAI will have an adverse effect on the interface energy level arrangement, which may lead to a negative work function shift, and then induce carrier accumulation at the upper interface of the perovskite active layer. In addition, the mismatch of the interface energy level can easily lead to the activation of halide ion migration on the surface of the N-type perovskite film, thereby exacerbating the instability of the device. Therefore, it is necessary to seek a reasonable molecule that can optimize the interface energy level structure.

[0069] In view of this, the present invention provides a self-assembling small molecule, the self-assembling small molecule having the following structural formula:

[0070]

[0071] The self-assembling small molecule designed and synthesized by the present invention has a large extended conjugated plane and a D-A1-A2-D type molecular structure. This type of molecular structure enables the self-assembling small molecule to have a relatively matched energy level. At the same time, the triphenylamine units on both sides also enable the self-assembling small molecule to have helical flanks, which can reduce the unfavorable accumulation of the self-assembling small molecule, help solution processing and promote the extraction of holes.

[0072] The present invention also provides a method for preparing the self-assembling small molecule as described above, comprising the following steps:

[0073] Preparation of intermediate 2: adding intermediate 1, 4-boric acid ester-4',4'-dimethoxytriphenylamine and catalyst 2 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 2, washing and extracting reactant 2 to obtain extract 2, drying and purifying extract 2 to obtain intermediate 2, wherein intermediate 1 is 5,9-dibromo-7H-dibenzo[c,g]carbazole;

[0074] Preparation of intermediate 3: adding the intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating for reaction to obtain reactant 3, washing and extracting the reactant 3 to obtain extract 3, and drying and purifying the extract 3 to obtain intermediate 3;

[0075] Preparation of intermediate 4: adding the intermediate 3, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde and catalyst 4 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 4, washing and extracting the reactant 4 to obtain extract 4, and drying and purifying the extract 4 to obtain intermediate 4;

[0076] Preparation of intermediate 5: adding the intermediate 4 and 2-diethoxyphosphorylacetonitrile to a mixture of an alkaline organic solution, toluene and piperidine, heating and refluxing the mixture, and evaporating the solvent to obtain reactant 5; dissolving, washing and extracting the reactant 5 to obtain an organic phase; and drying, evaporating and purifying the organic phase to obtain intermediate 5;

[0077] Preparation of self-assembling small molecules: the intermediate 5 is dissolved in an organic solvent, and trimethyl alkyl bromide is added to react, and then the self-assembling small molecules are obtained through quenching reaction, removal of solvent, and recrystallization.

[0078] In some embodiments, intermediate 1 can be purchased from the market, or prepared according to the preparation method disclosed in the technical field.

[0079] In some embodiments, Intermediate 1 has the following structural formula:

[0080]

[0081] In some embodiments, intermediate 2 is prepared by intermediate 1, and intermediate 2 has the following structural formula:

[0082]

[0083] In some embodiments, the molar ratio of intermediate 1 to 4-boronate-4',4'-dimethoxytriphenylamine is 1:(2.5-3); it can be any ratio between 1:(2.5-3) such as 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, 1:3, etc.

[0084] In some embodiments, Catalyst 2 comprises tetrakistriphenylphosphine palladium.

[0085] The addition of catalyst 2 can be determined according to the addition amount of the reactants intermediate 1 and 4-boric acid ester-4', 4'-dimethoxy triphenylamine, and it is good to promote the reaction of intermediate 1 and 4-boric acid ester-4', 4'-dimethoxy triphenylamine. In some embodiments, the molar ratio of catalyst 2, intermediate 1, and 4-boric acid ester-4', 4'-dimethoxy triphenylamine is 0.05:1:(2.5-3).

[0086] In some embodiments, the basic organic mixed aqueous solution includes anhydrous potassium carbonate, water, and tetrahydrofuran.

[0087] The amount of anhydrous potassium carbonate, water and tetrahydrofuran added to the alkaline organic mixed aqueous solution can be determined according to the amount of the reactants, so as to dissolve and disperse the reactants and promote their reaction. In some embodiments, the alkaline organic mixed aqueous solution includes 126 mg of anhydrous potassium carbonate, 2 ml of water and 15 ml of tetrahydrofuran.

[0088] In some embodiments, the reaction vessel for the heating reaction includes a double-necked flask, and the intermediate 1, 4-boric acid ester-4',4'-dimethoxytriphenylamine and catalyst 2 can be added to the double-necked flask filled with an alkaline organic mixed aqueous solution for heating reaction.

[0089] In some embodiments, before the heating reaction is performed, the oxygen in the reaction container can be exhausted with an inert gas, wherein the inert gas includes nitrogen. The oxygen in the reaction container can be removed by evacuating the gas three times under a nitrogen atmosphere.

[0090] In some embodiments, the temperature range of the heating reaction is 65° C. to 85° C. At the above reaction temperature, it is beneficial to promote the reaction of intermediate 1 and 4-boric acid ester-4',4'-dimethoxytriphenylamine to produce intermediate 2.

[0091] In some embodiments, heating the reaction under stirring conditions can promote the reaction and make the reaction more complete.

[0092] In some embodiments, the reaction time of the heating reaction is 12 hours to 24 hours.

[0093] In some embodiments, after the heating reaction is completed, the reactant 2 can be cooled to room temperature (25° C. to 30° C.) and then washed with water.

[0094] In some embodiments, the extraction process includes an extractant, and the extractant includes at least one of dichloromethane, ethyl acetate, and trichloroethane.

[0095] In some embodiments, the washed reactant 2 can be extracted three times with an extracting liquid to obtain an extracting liquid 2, thereby increasing the extraction rate of the product.

[0096] In the step of preparing the intermediate 2, the purpose of drying is to remove the extractant in the extract 2 to obtain a solid substance. In some embodiments, the extract 2 can be dried using a desiccant, and the desiccant includes anhydrous sodium sulfate; in some embodiments, the extract 2 can also be evaporated and dried by an evaporation method. For example, the extract 2 is dried using a rotary evaporator; in some embodiments, the extract 2 can also be dried by combining a desiccant and an evaporation method. For example, the extract 2 is dried using a desiccant to remove most of the extractant, and then the residual extractant is evaporated by the evaporation method, which is beneficial to improving the efficiency and effect of drying.

[0097] In some embodiments, purification comprises column chromatography.

[0098] In some embodiments, the column chromatography comprises an eluent comprising a mixture of n-hexane and dichloromethane.

[0099] In some embodiments, the volume ratio of n-hexane to dichloromethane is 5:1.

[0100] In some embodiments, column chromatography is used for purification, and after purification is completed, a drying step is also included to remove the residual eluent after purification. Exemplarily, the residual eluent can be removed by evaporation, and the evaporation method includes rotary evaporation.

[0101] In some embodiments, intermediate 3 is prepared by intermediate 2, and intermediate 3 has the following structural formula:

[0102]

[0103] In some embodiments, the molar ratio of intermediate 2 to 1,2-dibromobutane is 1:(15-30), which can be any ratio between 1:(15~30), such as 1:15, 1:16, 1:18, 1:20, 1:25, 1:28, 1:30, etc.

[0104] In some embodiments, Catalyst 3 includes tetrabutylammonium bromide (TBAB).

[0105] The amount of catalyst 3 added can be determined according to the amount of reactants added, preferably to promote the reaction. In some embodiments, the molar ratio of TBAB, intermediate 2, and 1,2-dibromobutane is 0.2:1:(15-30).

[0106] In some embodiments, the mass concentration of the potassium hydroxide aqueous solution is 50%.

[0107] In some embodiments, the temperature range of the heating reaction is 70° C. At the above reaction temperature, it is beneficial to promote the reaction of intermediate 2 and 1,2-dibromobutane to produce intermediate 3.

[0108] In some embodiments, the reaction time of the heating reaction is 12 hours to 24 hours.

[0109] In some embodiments, the spot plate reaction can be used to determine the extent of the reaction, and after the reaction is completed, the subsequent washing and extraction steps can be performed.

[0110] In some embodiments, after the heating reaction is completed, the reactant 3 can be cooled to room temperature (25° C. to 30° C.) and then washed with water.

[0111] In some embodiments, the extracting comprises an extractant comprising dichloromethane.

[0112] In some embodiments, the washed reactant 3 can be extracted three times with an extracting liquid to obtain an extracting liquid 3, thereby increasing the extraction rate of the product.

[0113] In the step of preparing the intermediate 3, the purpose of drying is to remove the extractant in the extract 3 to obtain a solid substance. In some embodiments, the extract 3 can be dried using a desiccant, and the desiccant includes anhydrous magnesium sulfate; in some embodiments, the extract 3 can also be evaporated and dried by an evaporation method. Exemplarily, the extract 3 is dried using a rotary evaporator; in some embodiments, the extract 3 can also be dried by combining a desiccant and an evaporation method. Exemplarily, the extract 3 is dried using a desiccant to remove most of the extractant, and then the residual extractant is evaporated by the evaporation method, which is beneficial to improving the efficiency and effect of drying.

[0114] In some embodiments, purification comprises purification by silica gel column chromatography.

[0115] In some embodiments, the silica gel column chromatography purification method includes an eluent, and the eluent includes a mixture of petroleum ether and dichloromethane.

[0116] In some implementations, the volume ratio of petroleum ether to dichloromethane is 3:1.

[0117] In some embodiments, purification is performed using silica gel column chromatography, and after purification is completed, a drying step is also included to remove the residual eluent after purification. Exemplarily, the residual eluent can be removed by evaporation, and the evaporation method includes rotary evaporation.

[0118] In some embodiments, intermediate 4 is prepared by intermediate 3, and intermediate 4 has the following structural formula:

[0119]

[0120] In some embodiments, the molar ratio of intermediate 3 and 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carbaldehyde is 1:(1.2-1.7), which can be any value in the range of 1:(1.2-1.7), such as 1:1.2, 1:1.5, 1:1.6, 1:1.7, etc.

[0121] In some embodiments, Catalyst 4 comprises tetrakistriphenylphosphine palladium.

[0122] The addition of catalyst 4 can be determined according to the amount of reactants added, and it is better to promote the reaction. In some embodiments, the molar ratio of catalyst 4 to intermediate 3 and 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde is 1:1.5:0.08.

[0123] In some embodiments, the basic organic mixed aqueous solution includes anhydrous potassium carbonate, water, and tetrahydrofuran.

[0124] The amount of the alkaline organic mixed aqueous solution added can be determined according to the amount of the reactants added, so as to fully dissolve and disperse the reactants and promote the reaction of the reactants.

[0125] In some embodiments, the volume of water in the alkaline organic mixed aqueous solution is 2 ml to 5 ml.

[0126] In some embodiments, the alkaline organic mixed aqueous solution includes 120 mg of anhydrous potassium carbonate, 2 ml of water and 15 ml of tetrahydrofuran, which is conducive to obtaining a stable alkaline organic mixed aqueous solution and fully dissolving and dispersing the reactants to promote their reaction.

[0127] In some embodiments, the reaction vessel for the heating reaction includes a double-necked flask, and the intermediate 3, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carbaldehyde and catalyst 4 can be added to the double-necked flask filled with an alkaline organic mixed aqueous solution for heating reaction.

[0128] In some embodiments, before the heating reaction is performed, the oxygen in the reaction container can be exhausted with an inert gas, wherein the inert gas includes nitrogen. The oxygen in the reaction container can be removed by evacuating the gas three times under a nitrogen atmosphere.

[0129] In some embodiments, the temperature range of the heating reaction is 65°C to 68°C. At the above reaction temperature, it is beneficial to promote the reaction of intermediate 3 and 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde to produce intermediate 4.

[0130] In some embodiments, heating the reaction under stirring conditions can promote the reaction and make the reaction more complete.

[0131] In some embodiments, the reaction time of the heating reaction is 12 hours to 24 hours.

[0132] In some embodiments, after the heating reaction is completed, the reactant 2 can be cooled to room temperature (25° C. to 30° C.) and then washed with water.

[0133] In some embodiments, the extraction process includes an extractant comprising dichloromethane.

[0134] In some embodiments, the washed reactant 4 can be extracted three times with an extracting liquid to obtain an extracting liquid 4, thereby increasing the extraction rate of the product.

[0135] In the step of preparing the intermediate 4, the purpose of drying is to remove the extractant in the extract 4 to obtain a solid substance. In some embodiments, the extract 4 can be dried using a desiccant, and the desiccant includes anhydrous sodium sulfate; in some embodiments, the extract 4 can also be evaporated and dried by an evaporation method. For example, the extract 4 is dried using a rotary evaporator; in some embodiments, the extract 4 can also be dried by combining a desiccant and an evaporation method. For example, the extract 4 is dried using a desiccant to remove most of the extractant, and then the residual extractant is evaporated by the evaporation method, which is beneficial to improving the efficiency and effect of drying.

[0136] In some embodiments, the column chromatography comprises an eluent comprising a mixture of n-hexane and dichloromethane.

[0137] In some embodiments, the volume ratio of n-hexane to dichloromethane is 6:1.

[0138] In some embodiments, column chromatography is used for purification, and after purification is completed, a drying step is also included to remove the residual eluent after purification. Exemplarily, the residual eluent can be removed by evaporation, and the evaporation method includes rotary evaporation.

[0139] In some embodiments, intermediate 5 is prepared by intermediate 4, and intermediate 5 has the following structural formula:

[0140]

[0141] In some embodiments, the molar ratio of intermediate 4 to 2-diethoxyphosphorylacetonitrile is 1:(12-30).

[0142] In the step of preparing the intermediate 5, the alkaline organic solution includes a mixed solution of toluene and piperidine or a mixed solution of toluene and pyridine.

[0143] In some embodiments, the volume ratio of toluene and piperidine is (15-25):(0.5-2), and can be any ratio in the range of (15-25):(0.5-2), such as 20:0.5, 15:0.5, 25:0.5, 25:2, 25:1, 15:2, 15:1, etc.

[0144] In some embodiments, the temperature range of the heating reflux reaction is 100°C to 120°C, which can be 100°C, 110°C, 120°C, etc. At the above reaction temperature, it is beneficial to promote the reaction of intermediate 4 and 2-diethoxyphosphorylacetonitrile to produce intermediate 5.

[0145] In some embodiments, the reaction time of the heating reflux reaction is 8 h to 12 h, which can be 8 h, 10 h, 12 h, etc.

[0146] In some embodiments, in the step of evaporating the solvent to obtain a solid substance, the solvent may be evaporated by rotary evaporation to obtain the solid substance.

[0147] In some embodiments, the obtained solid material is dissolved in an organic solvent, and the organic solvent includes dichloromethane.

[0148] In some embodiments, after the solid material is dissolved, it is washed with water.

[0149] In some embodiments, after the solid material is dissolved and washed, the organic phase is collected, and the organic phase contains the target product intermediate 5.

[0150] The collected organic phase contains an organic solvent, so the organic phase needs to be dried and evaporated to remove the organic solvent.

[0151] In some embodiments, the organic phase can be dried using a desiccant, and the desiccant includes anhydrous sodium sulfate. In some embodiments, the organic phase can also be dried by evaporation, and illustratively, the organic phase is dried using a rotary evaporator. In some embodiments, the organic phase can also be dried by combining a desiccant and evaporation, and illustratively, the organic phase is dried using a desiccant to remove most of the organic solvent, and then the residual organic solvent is evaporated by evaporation, which helps to improve the efficiency and effect of drying.

[0152] In some embodiments, purification comprises column chromatography.

[0153] In some embodiments, the column chromatography comprises an eluent comprising a mixture of dichloromethane and methanol.

[0154] In some embodiments, the volume ratio of dichloromethane to methanol is 10:1.

[0155] In this embodiment, a powdery intermediate 5 can be obtained after purification.

[0156] In the present invention, the self-assembling small molecule is prepared through intermediate 5, and the self-assembling small molecule has the following structural formula:

[0157]

[0158] The intermediate 5 is dissolved in an organic solvent, and trimethylsilyl bromide (TMSbr) is added to react to obtain the reactant 6. Methanol is added to the reactant 6, and the solvent is removed to obtain the self-assembling small molecule.

[0159] In some embodiments, the molar ratio of intermediate 5 to trimethylalkyl bromide is 1:(5-10).

[0160] In some embodiments, the organic solvent that dissolves the intermediate 5 includes dichloromethane.

[0161] In some embodiments, the reaction of intermediate 5 and trimethylalkyl bromide is carried out under an inert atmosphere, which includes argon.

[0162] In some embodiments, the reaction time of intermediate 5 and trimethylalkyl bromide is 12 h to 24 h.

[0163] In some embodiments, the quenching reaction is accomplished by adding methanol.

[0164] In some embodiments, the solvent is removed by adding methanol.

[0165] In some embodiments, the recrystallization is completed by adding methanol to obtain the self-assembled small molecule.

[0166] In some embodiments, the method of removing the solvent comprises evaporation.

[0167] In some embodiments, the evaporation method comprises rotary evaporation.

[0168] In this embodiment, after removing the solvent, powdered self-assembled small molecules can be obtained.

[0169] The self-assembling small molecule of the present invention is prepared in sequence through intermediate 1, intermediate 2, intermediate 3, intermediate 4, and intermediate 5. In one embodiment, refer to Figure 1The preparation process of the self-assembling small molecule of the present invention is as follows: first, intermediate 1 and 4-boric acid ester-4', 4'-dimethoxytriphenylamine are dissolved in an alkaline organic mixed aqueous solution composed of potassium carbonate, tetrahydrofuran and water, and heated to obtain intermediate 2 under the catalysis of tetrakistriphenylphosphine palladium catalyst, intermediate 2 and 1,2-dibromobutane are heated under the catalysis of tetrabutylammonium bromide catalyst to obtain intermediate 3, intermediate 3 and 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde are dissolved in potassium hydroxide aqueous solution, heated to obtain intermediate 4, intermediate 4 and 2-diethoxyphosphorylacetonitrile are heated and refluxed in a mixed solution of toluene and piperidine to obtain intermediate 5, and then intermediate 5 is reacted with trimethylsilyl bromide to obtain the self-assembling small molecule.

[0170] The present invention also provides an interface modification film, which includes the self-assembled small molecules as described above. The interface modification film is applied to a perovskite battery device, and the interface modification film is used to improve the interface contact with the perovskite active layer, passivate the interface defects of the perovskite active layer, and obtain a more suitable energy level, thereby promoting efficient and rapid hole extraction, and is also beneficial for the self-assembled molecules (SAM) to be fixed at the interface between the hole transport layer and the perovskite active layer, blocking the unfavorable lithium ion migration in the hole transport material, and improving the overall wet heat stability and structural stability of the perovskite battery device.

[0171] In some embodiments, the interface modification film also includes at least one of phenethylammonium bromide (PEAI) and its derivatives. On the basis of PEAI and its derivatives, the present invention adds self-assembling small molecules that can optimize the interface energy level structure, thereby solving the problem of energy level mismatch that easily occurs when PEAI and its derivatives passivate the perovskite active layer of the perovskite battery.

[0172] The present invention also provides a method for preparing the interface modification film as described above, comprising the following steps:

[0173] S10: dissolving the self-assembling small molecule and at least one of phenethylammonium bromide and its derivatives in an organic solvent to obtain an interface modification film precursor solution;

[0174] S20: spin coating the interface modification film precursor solution onto the surface of the substrate to form an interface modification film.

[0175] In some embodiments, the molar ratio of at least one of phenethylammonium bromide and its derivatives to the self-assembling small molecule is 1:(0.5-4), which can be any ratio within the range of 1:(0.5-4), such as 1:0.5, 1:1, 1:2, 1:3, 1:4, etc.

[0176] The interface modification film of the present invention includes the self-assembled small molecules as described above, which improves the interface contact with the perovskite active layer, passivates the interface defects of the perovskite active layer and obtains a more suitable energy level, thereby promoting efficient and rapid hole extraction, and is also beneficial for the self-assembled small molecules to be fixed at the interface between the hole transport layer and the perovskite active layer. Therefore, in some embodiments, the substrate includes a perovskite film, and the perovskite film can also be understood as the perovskite active layer in the perovskite battery. The interface modification film is prepared on the surface of the perovskite active layer, thereby exerting the above-mentioned beneficial effects of the interface modification film.

[0177] The present invention also provides a perovskite battery, which includes the interface modification film as described above and has at least all the beneficial effects of the interface modification film, which will not be described in detail here.

[0178] In some embodiments, an interface modification film is disposed on the surface of the perovskite active layer to form an interface modification layer, thereby improving the interface contact with the perovskite active layer, passivating the interface defects of the perovskite active layer and obtaining a more suitable energy level, thereby promoting efficient and rapid hole extraction, and facilitating the self-assembled small molecules to be fixed at the interface between the hole transport layer and the perovskite active layer.

[0179] In the present invention, the perovskite cell includes a formal perovskite cell and may also be an inverted perovskite cell.

[0180] In some embodiments, the perovskite cell includes a formal perovskite cell, and the perovskite cell includes a front electrode layer, an electron transport layer, a perovskite active layer, an interface modification layer, a hole transport layer and a back electrode layer from bottom to top. The interface modification layer includes the above-mentioned interface modification film.

[0181] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0182] Example 1

[0183] 1. Preparation of self-assembling small molecules

[0184] 5,9-Dibromo-7H-dibenzo[c,g]carbazole was used as intermediate 1.

[0185] Preparation of intermediate 2: Intermediate 1 (297.58 mg, 0.7 mmol), 4-boronic acid ester-4',4'-dimethoxytriphenylamine (910 mg, 2.1 mmol), tetrakistriphenylphosphine palladium (35 mg, 0.03 mmol), anhydrous potassium carbonate (126 mg, 0.9 mmol), 2 ml of water and 15 ml of tetrahydrofuran were added to a two-necked flask in sequence and heated under N 2The atmosphere was evacuated three times to remove oxygen, and the solution in the double-necked flask was heated to 65°C for stirring and reacting for 12 hours to obtain reactant 2. After reactant 2 was cooled to room temperature 25°C to 30°C, reactant 2 was washed with water and extracted with dichloromethane three times to obtain extract 2. By using anhydrous Na 2 SO 4 The crude product was dried on a rotary evaporator and purified by column chromatography (eluent: n-hexane / dichloromethane = 5 / 1 vol / vol). The eluent was then removed by rotary evaporation to obtain intermediate 2 (0.238 g, 80%).

[0186] Preparation of intermediate 3: In a 100 ml reaction tube, raw intermediate 2 (3.539 g, 4.05 mmol), 1,2-dibromobutane 9.7 ml, tetrabutylammonium bromide (260.2 mg, 0.81 mmol) and 2.2 ml of 50% potassium hydroxide aqueous solution were added in sequence, and then the temperature was raised to 70°C for reaction for 12 h. After the plate reaction was complete, the obtained reactant 3 was cooled to room temperature, washed with water, and then extracted with dichloromethane to obtain extract 3. The extract 3 was then dried with anhydrous magnesium sulfate, and the residual solution was dried with a rotary evaporator, and then purified by silica gel column chromatography to obtain intermediate 2 (2.690 g, 76%) (the eluent is as follows: petroleum ether / dichloromethane 3:1 v / v).

[0187] Preparation of intermediate 4: Intermediate 3 (201.8 mg, 0.2 mmol), 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carbaldehyde (71.4 mg, 0.3 mmol), tetrakis(triphenylphosphine)palladium (18.53 mg, 0.016 mmol), anhydrous potassium carbonate (120 mg, 0.87 mmol), 2 ml of water and 15 ml of tetrahydrofuran were added to a two-necked flask in sequence and heated under N 2 The atmosphere was evacuated three times to remove oxygen, and the mixed solution in the double-necked flask was heated to 65°C, and stirred at this temperature for 12 hours to obtain the reactant 4. After the reactant 4 was cooled to room temperature, the reactant 4 was washed with water and extracted with dichloromethane three times. 2 SO 4 The crude product was dried by rotary evaporator and purified by column chromatography (eluent: n-hexane / dichloromethane = 6 / 1 vol / vol), followed by rotary evaporation to remove CH 2 Cl 2 , intermediate 4 (159.4 mg, 79%) was obtained.

[0188] Preparation of Intermediate 5: In a 50 ml round-bottom flask, intermediate 4 (208.1 mg, 0.2 mmol), 2-diethoxyphosphorylacetonitrile (500 μl), toluene (20 ml) and piperidine (0.5 ml) were added under nitrogen protection, the temperature was raised to 110° C., and reflux reaction was carried out at this temperature for 10 hours to obtain reactant 5. After reactant 5 was cooled to room temperature, the organic solvent therein was removed by rotary evaporation, and then dissolved in dichloromethane, and then washed with water, the organic phase was collected, and the organic phase was dried over anhydrous sodium sulfate, and then dichloromethane was removed by rotary evaporation under reduced pressure, followed by purification by column chromatography (eluent is as follows: the volume ratio of dichloromethane and methanol is 10:1), and intermediate 5 (149.6 mg, 71.9%) was obtained in a powdery state.

[0189] Preparation of self-assembling small molecules: The obtained intermediate 5 (400 mg) was dissolved in 20 ml of dichloromethane, and 400 μl of TMSbr was added under argon protection to obtain a mixed solution. The mixed solution was allowed to stand overnight (12 h), 10 mL of methanol was added and mixed evenly, and then the solvent was removed by rotary evaporation under reduced pressure to obtain a powdered self-assembling small molecule. The self-assembling small molecule was represented by TPA-4PADCB-TCP.

[0190] 2. Preparation of perovskite cells

[0191] Cleaning of ITO conductive glass

[0192] The protective film in the ITO conductive glass was removed, and the ITO conductive glass was ultrasonically cleaned using deionized water with detergent, and then ultrasonically treated in deionized water, acetone, and isopropanol in sequence for 20 minutes for use.

[0193] SnO 2 Preparation of electron transport layer

[0194] Add SnO in a volume ratio of 1:3 into a glass bottle that has been ultrasonically cleaned with deionized water, ethylene dichloride, and isopropanol and dried. 2 The hydrosol was mixed with pure water and shaken for 30 min to make it dispersed evenly and filtered to obtain SnO 2 Solution.

[0195] Use a hot air gun to dry the cleaned ITO conductive glass and place it in a UV ozone treatment machine for 20 minutes. Take out the ITO conductive glass and wait for it to cool to room temperature. Then place it on a glue spreader and use a pipette to drop 50 μl of SnO mixed evenly. 2The solution was then coated with a spin coating speed of 3000 rpm for 30 seconds. After the spin coating was completed, the ITO conductive glass was placed on a hot plate at 150°C for 30 minutes of thermal annealing to remove moisture. SnO 2 Electron transport layer.

[0196] Preparation of perovskite active layer

[0197] Combine 19.8mg CsI, 16.2mg MABr, 20.3mg MACl, 224.4mg FAI, 742.2mg PbI 2 The powder mixture was dissolved in 1 ml of anhydrous DMF / DMSO mixture solvent, with a volume ratio of DMF / DMSO of 4:1, and stirred at 60°C for 2 hours to fully dissolve various raw materials to obtain a perovskite precursor solution. The components of the perovskite precursor solution are as follows: Cs 0.05 FA 0.85 MA 0.1 Pb(I 0.97 Br 0.03 ) 3 , concentration is 1.61 mol·L -1 .

[0198] Pipette 50 μl of the above perovskite precursor solution and spin coat it on SnO 2 The surface of the electron transport layer was spin-coated at 1000 rpm for 10 s and 5000 rpm for 30 s. 100 μl of anti-solvent chlorobenzene was added within 20 to 25 s after the second program was started, and then placed on a 150 ° C hot stage for annealing for 10 min. 2 A perovskite active layer is formed on the surface of the electron transport layer.

[0199] Preparation of composite passivation layer, i.e. preparation of interface modification layer

[0200] Phenethylammonium bromide (PEAI) and the self-assembling small molecule (TPA-4PADCB-TCP) prepared in this example were dissolved in isopropanol solution, and the mixture was shaken to fully dissolve to obtain a mixed solution. The total concentration of the mixed solution was 5 mg·mL -1 The following is a mixture of PEAI and TPA-4PADCB-TCP in a molar ratio of 1: (0.5-4). Next, in a glove box with a nitrogen atmosphere, the ITO conductive glass cooled to room temperature was placed on a coater, and 100 μl of the mixed solution was statically spin-coated on the perovskite active layer at a speed of 5000 rpm for 30 seconds. After the spin coating, it was placed on a hot plate at 100°C for thermal annealing for 10 minutes to obtain a composite passivation layer.

[0201] Preparation of hole transport layer

[0202] 144.6 mg of Spiro-OMeTAD was weighed in a glove box, and then 2 ml of ultra-dry chlorobenzene, 35 μl of Li-TFSI acetonitrile solution (the concentration of Li-TFSI was 520 mg mL -1 ), 56.8μl of tributyl phosphate (tBP), sealed with a sealing film, stirred at 60°C for 2h to fully dissolve and filtered to obtain a hole transport precursor solution for use. The ITO conductive glass prepared with a composite passivation layer was placed on a coater, and 40μl of the hole transport precursor solution was dropped on the surface of the composite passivation layer by static spin coating. The spin coating speed was 4000rpm, and the spin coating lasted for 30s. After the spin coating was completed, the Spiro-OMe-TAD hole transport layer was obtained.

[0203] Preparation of metal electrodes

[0204] In the glove box, the ITO conductive glass prepared as the hole transport layer was placed in a metal vacuum evaporation chamber, and then a 100nm thick Ag electrode layer was evaporated at a high vacuum degree, finally obtaining a complete area of ​​0.06cm 2 Perovskite battery devices.

[0205] Comparative Example 1

[0206] Comparative Example 1: A formal perovskite battery device was prepared with reference to Example 1. However, the difference is that in the step of preparing the passivation layer, the self-assembled small molecule material prepared in Example 1 was not added. Instead, PEAI was used as a raw material to prepare the PEAI passivation layer. The structure of the prepared perovskite battery was ITO / SnO 2 / Cs 0.05 FA 0.85 MA 0.1 Pb(I 0.97 Br 0.03 ) 3 / PEAI / Spiro-OMeTAD / Ag

[0207] Performance Testing

[0208] Under standard sunlight (AM 1.5G), the perovskite cells prepared in Example 1 and Comparative Example 1 were tested for device performance, and the obtained current density-voltage curves are shown in FIG. Figure 1 As shown, wherein comparative example 1 is represented by control, and example 1 is represented by PEAI / SAM, the measured data are shown in Table 1.

[0209] Table 1

[0210] <![CDATA[Jsc(mA cm -2 )]]> Voc(V) FF(%) PCE(%) Example 1 24.61 1.144 83.56 23.52 Comparative Example 1 24.49 1.105 82.37 22.28

[0211] from Figure 2 As shown in Table 1, TPA-4PADCB-TCP has a large extended conjugated plane and a D-A1-A2-D type molecular structure. This type of molecular structure has a relatively matched energy level. In addition, the triphenylamine units on both sides also make the self-assembled small molecule have a spiral flank, which can reduce the unfavorable stacking of the self-assembled small molecules, help solution processing and promote the extraction of holes, and improve the photoelectric conversion efficiency of the device. TPA-4PADCB-TCP is used as a synergistic passivation material and is prepared together with phenethylammonium bromide into a composite passivation layer for application in perovskite battery devices, which can improve the interaction with perovskite activity. The interface contact of the active layer can passivate the interface defects of the perovskite active layer and obtain a more suitable energy level, thereby promoting efficient and rapid hole extraction. It is also beneficial for the SAM molecules to be fixed at the interface of the hole transport layer and the perovskite active layer, blocking the unfavorable lithium ion migration in the hole transport material Spiro, improving the overall wet and hot stability of the perovskite device, and also improving the structural stability of the device. The open circuit voltage Voc of the perovskite battery reverse scanning device prepared with the composite passivation layer of PEAI / TPA-4PADCB-TCP is 1.144V, and the short circuit current is 24.61mA / cm -2 , the filling factor is 83.56%, and the photoelectric conversion efficiency is 23.52%. The results show that TPA-4PADCB-TCP has great application potential as a synergistic passivation material in formal perovskite battery devices.

[0212] Comparative Example 1 only uses phenethylammonium bromide as a passivation material to prepare a passivation layer, and its photoelectric conversion efficiency is reduced.

[0213] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A self-assembling small molecule, characterized in that: The self-assembling small molecule has the following structural formula:

2. A method for preparing the self-assembling small molecule according to claim 1, characterized in that: The following steps are involved: Preparation of intermediate 2: adding intermediate 1, 4-boric acid ester-4',4'-dimethoxytriphenylamine and catalyst 2 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 2, washing and extracting reactant 2 to obtain extract 2, drying and purifying extract 2 to obtain intermediate 2, wherein intermediate 1 is 5,9-dibromo-7H-dibenzo[c,g]carbazole; Preparation of intermediate 3: adding the intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating for reaction to obtain reactant 3, washing and extracting the reactant 3 to obtain extract 3, and drying and purifying the extract 3 to obtain intermediate 3; Preparation of intermediate 4: adding the intermediate 3, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde and catalyst 4 to an alkaline organic mixed aqueous solution, heating for reaction to obtain reactant 4, washing and extracting the reactant 4 to obtain extract 4, and drying and purifying the extract 4 to obtain intermediate 4; Preparation of intermediate 5: adding the intermediate 4 and 2-diethoxyphosphorylacetonitrile to an alkaline organic solution, heating and refluxing the solution, and evaporating the solvent to obtain reactant 5; dissolving, washing, and extracting the reactant 5 to obtain an organic phase; and drying, evaporating, and purifying the organic phase to obtain intermediate 5; Preparation of self-assembling small molecules: the intermediate 5 is dissolved in an organic solvent, and trimethyl alkyl bromide is added to react, and then the self-assembling small molecules are obtained through quenching reaction, removal of solvent, and recrystallization.

3. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: The structural formulas of intermediate 1, intermediate 2, intermediate 3, intermediate 4 and intermediate 5 are as follows:

4. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: In the step of preparing intermediate 2, The molar ratio of the intermediate 1 to 4-boronate-4',4'-dimethoxytriphenylamine is 1:(2.5-3); And / or, the catalyst 2 comprises tetrakistriphenylphosphine palladium; And / or, the alkaline organic mixed aqueous solution comprises anhydrous potassium carbonate, water and tetrahydrofuran; And / or, the temperature range of the heating reaction is 65°C to 85°C; And / or, the reaction time of the heating reaction is 12h to 24h; And / or, the extraction comprises an extraction liquid, and the extraction liquid comprises at least one of dichloromethane, ethyl acetate, and trichloroethane; And / or, the purifying comprises column chromatography.

5. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: In the step of preparing intermediate 3: The molar ratio of the intermediate 2 to 1,2-dibromobutane is 1:(15-30); And / or, the catalyst 3 comprises tetrabutylammonium bromide; And / or, the alkaline solvent includes an aqueous solution of potassium hydroxide and an aqueous solution of sodium hydroxide; And / or, the temperature range of the heating reaction is 65°C to 85°C; And / or, the reaction time of the heating reaction is 12h to 24h; and / or, the extraction comprises an extraction liquid, and the extraction liquid comprises dichloromethane; And / or, the purification comprises silica gel column chromatography purification.

6. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: In the step of preparing intermediate 4: The molar ratio of the intermediate 3 to 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxaldehyde is 1:(1.2-1.7); And / or, the catalyst 4 comprises tetrakistriphenylphosphine palladium; and / or, the molar content of the catalyst 4 is in the range of 0.08 mmol to 0.2 mmol; And / or, the alkaline organic mixed aqueous solution comprises anhydrous potassium carbonate, water and tetrahydrofuran; And / or, the temperature range of the heating reaction is 65°C to 85°C; And / or, the reaction time of the heating reaction is 12h to 24h.

7. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: In the step of preparing intermediate 5: and / or, the molar ratio of the intermediate 4 to 2-diethoxyphosphorylacetonitrile is 1:(12-30); And / or, the alkaline organic solution comprises a mixed solution of toluene and piperidine or a mixed solution of toluene and pyridine; And / or, the temperature range of the heating reflux reaction is 100° C. to 120° C.; And / or, the reaction time of the heating reflux reaction is 8h to 12h.

8. The method for preparing the self-assembling small molecule according to claim 2, characterized in that: In the step of preparing the self-assembling small molecule: The molar ratio of the intermediate 5 to trimethylbromethane is 1:(5-10); and / or, completing the quenching reaction by adding methanol; and / or, removing the solvent by adding methanol; And / or, the recrystallization is completed by adding methanol to obtain the self-assembling small molecule.

9. An interface modification film, which is applied to a perovskite battery, characterized in that: The interface modification film comprises the self-assembled small molecules according to claim 1.

10. The interface modification film according to claim 9, characterized in that: The interface modification film further comprises at least one of phenethylammonium bromide and its derivatives.

11. A method for preparing an interface modification film according to claim 9 or 10, characterized in that: The following steps are involved: Dissolving the self-assembling small molecule according to claim 1 and at least one of phenethylammonium bromide and its derivatives in an organic solvent to obtain an interface modification film precursor solution; The interface modification film precursor solution is spin-coated onto the surface of the substrate to form an interface modification film.

12. The method for preparing the interface modification film according to claim 11, characterized in that: The molar ratio of at least one of the phenethylammonium bromide and its derivatives to the self-assembling small molecule is 1:(0.5-4).

13. A perovskite battery, characterized in that: The perovskite battery comprises the interface modification film according to claim 9 or 10.

14. The perovskite battery according to claim 13, characterized in that: The interface modification film is arranged on the surface of the perovskite active layer.

15. The perovskite cell according to claim 14, characterized in that: The perovskite cell includes a formal perovskite cell, which includes, from bottom to top, a front electrode layer, an electron transport layer, the perovskite active layer, an interface modification layer, a hole transport layer and a back electrode layer; Wherein, the interface modification layer includes the interface modification film.

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