Self-assembled small molecules and preparation method, interface modification film and perovskite battery

Abstract

The present invention discloses a self-assembling small molecule, a preparation method thereof, an interface modification film, and a perovskite cell, belonging to the field of perovskite cell technology. The self-assembling small molecule designed and synthesized in the present invention has a large extended conjugated plane and a D-A1-A2-D molecular structure, which can be applied to perovskite cells to solve the technical problem of interfacial energy level mismatch that is common in perovskite cells.

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 phenylethylammonium bromide (PEAI) or its derivatives as passivating agents has become a common process for preparing high-efficiency perovskite cells. However, although PEAI and its derivatives have effectively passivated the upper surface of the perovskite active layer, the problem of energy level mismatch still exists. PEAI can adversely affect the interface energy level arrangement, potentially leading to a negative work function shift, which in turn induces carrier accumulation at the upper interface of the perovskite active layer. In addition, the interface energy level mismatch 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 rational 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 to solve the technical problem of interface energy level mismatch that easily occurs in perovskite batteries.

[0004] To achieve the above object, the present invention provides a self-assembling small molecule having 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-boronic 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, and 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 intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating to react to obtain reactant 3, washing and extracting reactant 3 to obtain extract 3, and drying and purifying 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 intermediate 4 and 2-diethoxyphosphorylacetonitrile to a mixture of an alkaline organic solution, toluene, and piperidine, heating under reflux, and evaporating the solvent to obtain reactant 5; dissolving reactant 5, washing, and extracting 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 trimethylalkyl 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 purification 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 comprises 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 12 hours to 24 hours.

[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 embodiments of the present invention, in the step of preparing the self-assembling small molecule:

[0044] The molar ratio of the intermediate 5 to trimethylbromide 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 includes the self-assembled small molecules 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 a substrate to form an interface modification film.

[0053] In some embodiments of the present invention, the molar ratio of the 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 includes 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 in 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 give the self-assembling small molecule helical flanks, which can reduce the unfavorable stacking of the self-assembling small molecule, facilitate 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 serve 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. It 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 and thermal 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 any creative work.

[0062] Figure 1 Schematic diagram of the preparation process of self-assembled small molecules according to one 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 purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

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

[0066] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0067] In the present invention, descriptions such as "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions of various embodiments may be combined with each other, but this must be based on the fact that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions is mutually 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 claimed by the present invention.

[0068] The use of phenylethylammonium 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 passivated the upper surface of the perovskite active layer well, there is still a problem of energy level mismatch. 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 molecular that can optimize the interface energy level structure.

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

[0070]

[0071] The self-assembling small molecule designed and synthesized in 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 give the self-assembling small molecule helical flanks, which can reduce the unfavorable stacking of the self-assembling small molecule, facilitate 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-boronic 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, and 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 intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating to react to obtain reactant 3, washing and extracting reactant 3 to obtain extract 3, and drying and purifying 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 intermediate 4 and 2-diethoxyphosphorylacetonitrile to a mixture of an alkaline organic solution, toluene, and piperidine, heating under reflux, and evaporating the solvent to obtain reactant 5; dissolving reactant 5, washing, and extracting 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 trimethylalkyl 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 art.

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

[0080]

[0081] In some embodiments, intermediate 2 is prepared from 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, and 1:3.

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

[0085] The amount of catalyst 2 added can be determined based on the amount of intermediate 1 and 4-boronate-4',4'-dimethoxytriphenylamine added, preferably to promote the reaction between intermediate 1 and 4-boronate-4',4'-dimethoxytriphenylamine. In some embodiments, the molar ratio of catalyst 2, intermediate 1, and 4-boronate-4',4'-dimethoxytriphenylamine 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 based on the amount of the reactants 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-boronate-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, the oxygen in the reaction vessel can be exhausted with an inert gas, which includes nitrogen. The oxygen in the reaction vessel can be removed by evacuating the gas three times under a nitrogen atmosphere.

[0090] In some embodiments, the heating reaction temperature ranges from 65° C. to 85° C. The above reaction temperature is conducive to promoting the reaction of intermediate 1 and 4-boronic 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 comprising at least one of dichloromethane, ethyl acetate, and trichloroethane.

[0095] In some embodiments, the washed reactant 2 can be extracted three times with the extraction liquid to obtain the extraction liquid 2, thereby improving 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 evaporation. 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 evaporation. This is conducive to improving the efficiency and effect of drying.

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

[0098] In some embodiments, the column chromatography method 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, purification is performed using column chromatography, and after purification is completed, a drying step is further included to remove the residual eluent after purification. For example, the residual eluent can be removed by evaporation, and the evaporation method includes rotary evaporation.

[0101] In some embodiments, intermediate 3 is prepared from 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, and 1:30.

[0104] In some embodiments, catalyst 3 comprises tetrabutylammonium bromide (TBAB).

[0105] The amount of catalyst 3 added can be determined based on 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 entered.

[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 the extraction liquid to obtain the extraction liquid 3, thereby improving 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 evaporation. For example, 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. For example, the extract 3 is dried using a desiccant to remove most of the extractant, and then the residual extractant is evaporated by evaporation. This is conducive 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 comprising 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. After purification is completed, a drying step is further included to remove the residual eluent after purification. For example, the residual eluent can be removed by evaporation, and the evaporation method includes rotary evaporation.

[0118] In some embodiments, intermediate 4 is prepared from 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-carboxaldehyde 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 amount of catalyst 4 added can be determined based on the amount of reactants added, preferably 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, thereby promoting 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-carboxaldehyde 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, the oxygen in the reaction vessel can be exhausted with an inert gas, which includes nitrogen. The oxygen in the reaction vessel 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 the extraction liquid to obtain the extraction liquid 4, thereby improving 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 evaporation. 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 evaporation. This is conducive to improving the efficiency and effect of drying.

[0136] In some embodiments, the column chromatography method 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, purification is performed using column chromatography, and after purification is completed, a drying step is further included to remove the residual eluent after purification. For example, 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 hours to 12 hours, which can be 8 hours, 10 hours, 12 hours, etc.

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

[0147] In some embodiments, the resulting solid material is dissolved in an organic solvent, which 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, which includes anhydrous sodium sulfate. In some embodiments, the organic phase can also be dried by evaporation, for example, using a rotary evaporator to dry the organic phase. In some embodiments, the organic phase can also be dried by combining a desiccant and an evaporation method, for example, using a desiccant to dry the organic phase to remove most of the organic solvent, and then using an evaporation method to evaporate the remaining organic solvent, 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 method 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 for dissolving the intermediate 5 comprises 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 hours to 24 hours.

[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, referring to Figure 1The preparation process of the self-assembling small molecule of the present invention is as follows: first, intermediate 1 and 4-boronic acid ester-4',4'-dimethoxytriphenylamine are dissolved in an alkaline organic mixed aqueous solution composed of potassium carbonate, tetrahydrofuran and water, and heated to react under the catalysis of tetrakistriphenylphosphine palladium to obtain intermediate 2; intermediate 2 and 1,2-dibromobutane are heated under the catalysis of tetrabutylammonium bromide to react 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 a potassium hydroxide aqueous solution and heated to react to obtain intermediate 4; intermediate 4 and 2-diethoxyphosphorylacetonitrile are heated and refluxed in a mixed solution of toluene and piperidine to prepare intermediate 5; then intermediate 5 is reacted with trimethylsilyl bromide to prepare 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. It 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 and hot stability and structural stability of the perovskite battery device.

[0171] In some embodiments, the interface modification film further includes at least one of phenylethylammonium bromide (PEAI) and its derivatives. The present invention adds self-assembling small molecules capable of optimizing the interface energy level structure on the basis of PEAI and its derivatives, 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, 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, or 1:4.

[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 provided 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-assembly of small molecules 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 comprises a formal perovskite cell, which comprises, from bottom to top, 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. The interface modification layer comprises the aforementioned interface modification film.

[0181] The technical solutions of the present invention are 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. The mixture was evacuated three times under N2 atmosphere to remove oxygen, and the solution in the two-necked flask was heated to 65°C for 1 h. The reaction was stirred for 12 h to obtain reactant 2. After reactant 2 was cooled to room temperature of 25°C to 30°C, reactant 2 was washed with water and extracted three times with dichloromethane to obtain extract 2. The extract was dried using anhydrous Na2SO4 and a rotary evaporator to obtain a crude product. The crude product was purified by column chromatography (eluent as follows: n-hexane / dichloromethane = 5 / 1 vol / vol), and the eluent was removed by rotary evaporation to obtain intermediate 2 (0.238 g, 80%).

[0186] Preparation of intermediate 3: In a 100 ml reaction tube, the raw material intermediate 2 (3.539 g, 4.05 mmol), 1,2-dibromobutane 9.7 ml, tetrabutylammonium bromide (260.2 mg, 0.81 mmol) and 50% potassium hydroxide aqueous solution 2.2 ml were added in sequence, and then the temperature was raised to 70 ° C 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 over anhydrous magnesium sulfate, and the residual solution was dried using a rotary evaporator, and then purified by silica gel column chromatography to obtain intermediate 2 (2.690 g, 76%) (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 the mixture was evacuated three times under N2 atmosphere to remove oxygen. The mixed solution in the double-necked flask was heated to 65°C, and the reaction was stirred at this temperature for 12 hours to obtain reactant 4. After reactant 4 was cooled to room temperature, reactant 4 was washed with water and extracted three times with dichloromethane. The crude product was obtained by drying with anhydrous Na2SO4 and a rotary evaporator. The crude product was purified by column chromatography (eluent is as follows: n-hexane / dichloromethane = 6 / 1 vol / vol), and then CH2Cl2 was removed by rotary evaporation to obtain intermediate 4 (159.4 mg, 79%).

[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 the reaction was refluxed at this temperature for 10 hours to obtain reactant 5. After the reactant 5 was cooled to room temperature, the organic solvent was removed by rotary evaporation, and then it was dissolved in dichloromethane and washed with water. The organic phase was collected and dried over anhydrous sodium sulfate. The dichloromethane was then removed by rotary evaporation under reduced pressure, and then purified by column chromatography (eluent: dichloromethane and methanol, volume ratio 10:1) to obtain intermediate 5 (149.6 mg, 71.9%) in the form of a powder.

[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 isopropyl alcohol in sequence for 20 minutes for later use.

[0193] Preparation of SnO2 electron transport layer

[0194] SnO2 hydrosol and purified water were added to a glass bottle that had been ultrasonically cleaned with deionized water, dichloroethane, and isopropyl alcohol and dried at a volume ratio of 1:3. The mixture was shaken for 30 minutes to disperse the mixture evenly and filtered to obtain a SnO2 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 50μl of thoroughly mixed SnO2 solution. Then start the spin coating program with a speed of 3000rpm and a time of 30s. After the spin coating is completed, place the ITO conductive glass on a hot plate at 150℃ for 30 minutes of thermal annealing to remove moisture. The SnO2 electron transport layer can be obtained on the surface of the ITO conductive glass.

[0196] Preparation of perovskite active layer

[0197] A mixture of 19.8 mg CsI, 16.2 mg MABr, 20.3 mg MACl, 224.4 mg FAI, and 742.2 mg PbI2 powders was dissolved in 1 ml of anhydrous DMF / DMSO mixture solvent with a volume ratio of DMF / DMSO of 4:1. The mixture was stirred at 60 °C for 2 hours to fully dissolve the various raw materials to obtain a perovskite precursor solution. The components of the perovskite precursor solution are as follows: CsI 0.05 FA 0.85 MA 0.1 Pb(I 0.97 Br 0.03 )3, the concentration is 1.61 mol·L -1 .

[0198] 50 μl of the perovskite precursor solution was spin-coated onto the surface of the SnO2 electron transport layer at a speed of 1000 rpm for 10 seconds and 5000 rpm for 30 seconds. Between 20 and 25 seconds after starting the second spin-coating cycle, 100 μl of the anti-solvent chlorobenzene was added dropwise. The sample was then annealed on a 150°C hotplate for 10 minutes to form a perovskite active layer on the surface of the SnO2 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 shaken to fully dissolve to obtain a mixed solution. The total concentration of the mixed solution was 5 mg·mL -1 The molar ratio of PEAI to TPA-4PADCB-TCP in the mixed solution is 1:(0.5-4). Next, in a nitrogen-filled glove box, ITO conductive glass cooled to room temperature was placed on a spin coater. 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 spin coating, the composite passivation layer was annealed on a hot plate at 100°C for 10 minutes.

[0201] Preparation of hole transport layer

[0202] In a glove box, 144.6 mg of Spiro-OMeTAD was weighed, and then 2 ml of ultra-dry chlorobenzene, 35 μl of Li-TFSI acetonitrile solution (the concentration of Li-TFSI was 520 mg mL) were added in sequence. -1), 56.8 μl of tributyl phosphate (tBP), sealed with parafilm, stirred at 60°C for 2 hours to fully dissolve, and filtered to obtain a hole transport precursor solution for later use. The ITO conductive glass with the composite passivation layer was placed on a spin coater. 40 μl of the hole transport precursor solution was dropwise added to the surface of the composite passivation layer using static spin coating at a speed of 4000 rpm for 30 seconds. The Spiro-OMe-TAD hole transport layer was obtained upon completion of the spin coating process.

[0203] Preparation of metal electrodes

[0204] In the glove box, the ITO conductive glass with the prepared 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 alone as a raw material to form a PEAI passivation layer. The structure of the prepared perovskite battery was ITO / SnO2 / 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 subjected to device performance tests, and the current density-voltage curves obtained were as follows: Figure 1 As shown, wherein comparative example 1 is represented by control and example 1 is represented by PEAI / SAM, and 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 2As 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 helical side wings, which can reduce the unfavorable accumulation of self-assembled small molecules, help solution processing and promote hole extraction, and improve the photoelectric conversion efficiency of the device. Using TPA-4PADCB-TCP as a synergistic passivation material and phenylethylammonium bromide to prepare a composite passivation layer for application in perovskite battery devices can improve the interaction with perovskite activity. The interface contact of the active layer can passivate the interface defects of the perovskite active layer while obtaining 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 scan device with a composite passivation layer prepared using 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] In Comparative Example 1, only phenethylammonium bromide was used as the passivation material to prepare the passivation layer, and its photoelectric conversion efficiency was 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 description 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-boronic 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, and 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 intermediate 2, 1,2-dibromobutane and catalyst 3 to an alkaline solution, heating to react to obtain reactant 3, washing and extracting reactant 3 to obtain extract 3, and drying and purifying 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 under reflux, and evaporating the solvent to obtain reactant 5; dissolving the reactant 5, washing, and extracting to obtain an organic phase; and drying, evaporating, and purifying the organic phase to obtain intermediate 5; Preparation of self-assembling small molecules: dissolving the intermediate 5 in an organic solvent, adding trimethylsilyl bromide to react, and then quenching the reaction, removing the solvent, and recrystallizing to obtain the self-assembling small molecules; The structural formulas of intermediate 1, intermediate 2, intermediate 3, intermediate 4 and intermediate 5 are as follows: 、 、 、 、 。 3. The method for preparing the self-assembling small molecule according to claim 2, wherein: 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); Or, the catalyst 2 is tetrakistriphenylphosphine palladium; Alternatively, the alkaline organic mixed aqueous solution is anhydrous potassium carbonate, water and tetrahydrofuran; Alternatively, the temperature range of the heating reaction is 65°C to 85°C; Alternatively, the heating reaction time is 12h~24h; Or, the extraction includes an extractant, and the extractant is at least one of dichloromethane, ethyl acetate, and trichloroethane; Alternatively, the purification comprises column chromatography.

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

5. The method for preparing the self-assembling small molecule according to claim 2, wherein: 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); Or, the catalyst 4 is tetrakistriphenylphosphine palladium; Alternatively, the alkaline organic mixed aqueous solution is anhydrous potassium carbonate, water and tetrahydrofuran; Alternatively, the temperature range of the heating reaction is 65°C to 85°C; Alternatively, the reaction time of the heating reaction is 12h~24h.

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

7. 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 trimethylsilyl bromide is 1:(5-10); Alternatively, the quenching reaction is completed by adding methanol; Alternatively, the self-assembling small molecule is obtained by adding methanol to complete the recrystallization.

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

9. The interface modification film according to claim 8, characterized in that: The interface modification film further comprises phenethylammonium bromide.

10. A method for preparing an interface modification film according to claim 9, characterized in that: The following steps are involved: Dissolving the self-assembling small molecule according to claim 1 and phenethylammonium bromide 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 a substrate to form an interface modification film.

11. The method for preparing the interface modification film according to claim 10, characterized in that: The molar ratio of the phenethylammonium bromide to the self-assembling small molecules is 1:(0.5-4).

12. A perovskite battery, characterized in that: The perovskite battery comprises the interface modification film according to claim 8 or 9.

13. The perovskite cell according to claim 12, characterized in that: The interface modification film is arranged on the surface of the perovskite active layer.

14. The perovskite cell according to claim 13, characterized in that The perovskite cell is a formal perovskite cell, which comprises, 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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