Polytriazoles and methods of making and using the same

Abstract

The application relates to the field of solar cell materials, and discloses a polytriazene, a preparation method and application thereof, the polytriazene contains structural units formed by alkenyl dioxothiophene and structural units formed by halogenated triphenylamine, the alkenyl dioxothiophene is at least one of monomers shown in formulas (I-1), (I-2) and (I-3), and the halogenated triphenylamine is a monomer shown in formula (II), wherein R1, R2 and R3 are one of H, an alkyl group and an alkoxy group; R4, R5 and R6 are one of an alkyl group, an alkoxy group and an alkylthio group; and X1 and X2 are halogens respectively. The polytriazene is synthesized by direct arylization polycondensation, has low cost, high efficiency, is more green and environment-friendly, can improve the wettability of a perovskite precursor solution to a polytriazene hole transport layer film, is of great significance for further improving the performance of a perovskite solar cell and promoting large-scale commercialization of the perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell materials, specifically to a polytriarylamine, its preparation method, and its applications. Background Technology

[0002] Polytriarylamines (PTA) have attracted considerable attention as hole transport layers in perovskite solar cells due to their good air stability, excellent hole transport capability, suitable electrochemical energy levels, and ability to be fabricated into amorphous thin films. After several years of structural optimization, the energy conversion efficiency of perovskite solar cells based on PTA hole transport materials has significantly improved, but their overall performance remains relatively low compared to other types of hole transport materials. This is mainly attributed to the high hydrophobicity of PTA and its poor compatibility with perovskite, making it difficult for the perovskite solution to spread when preparing the perovskite layer on the PTA film, resulting in poor quality perovskite films. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems of poor wettability, high cost, and low reaction efficiency of polytriarylamines in the prior art, and to provide a polytriarylamine, its preparation method, and its application. This polytriarylamine has a strong interaction with perovskite, which can improve the wettability of the perovskite precursor solution on the polytriarylamine hole transport layer film. Moreover, this polytriarylamine is synthesized by direct arylification condensation polymerization, which has low synthesis cost, high reaction efficiency, and is more efficient, green, and environmentally friendly. It is of great significance for further improving the performance of perovskite solar cells and promoting their large-scale commercialization.

[0004] To achieve the above objectives, the present invention provides a polytriarylamine containing structural units formed of alkenyl dioxythiophene and structural units formed of halotriphenylamine, wherein the alkenyl dioxythiophene is at least one of the monomers shown in formula (I-1), formula (I-2), and formula (I-3), and the halotriphenylamine is the monomer shown in formula (II).

[0005]

[0006] Among them, R1, R2, and R3 are each independently selected from H, C1-C 16 Alkyl and C1-C 16 One of the alkoxy groups;

[0007] R4, R5 and R6 are each independently selected from one of C1-C6 alkyl, C1-C6 alkoxy and C1-C6 alkylthio groups;

[0008] X1 and X2 are both halogens.

[0009] Preferably, in the alkenyldioxythiophene, R1, R2, and R3 are each independently selected from H and any one of the groups shown in formulas (1) to (4):

[0010] Where m = 1 - 11,

[0011] Preferably, the alkenyl dioxythiophene is at least one of 3,4-ethylene dioxythiophene, 3,4-(2,2-dimethylpropenedioxy)thiophene, and 3,4-styrene dioxythiophene.

[0012] Preferably, in the halotriphenylamine, R4, R5 and R6 are each independently selected from one of methyl, methoxy and methylthio.

[0013] Preferably, the halogenated triphenylamine is at least one selected from N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline, N,N-bis(4-bromophenyl)-2,4,6-trimethoxyaniline, and N,N-bis(4-bromophenyl)-2,4,6-trimethylthioaniline.

[0014] Preferably, the molar ratio of the structural unit formed by alkenyl dioxythiophene to the structural unit formed by halotriphenylamine is (0.8-1.2):1, more preferably (1-1.2):1.

[0015] Preferably, the number-average molecular weight of the polytriarylamine is 5,000 to 30,000 g / mol.

[0016] A second aspect of the present invention provides a method for preparing the aforementioned polytriarylamine, the method comprising: polymerizing a halotriphenylamine and an alkenyl dioxothiophene in the presence of a catalyst under an inert atmosphere.

[0017] Preferably, during the polymerization reaction, the reaction system also contains organic acids, bases, organic solvents, and optional ligands.

[0018] Preferably, the molar ratio of the halotriphenylamine, the alkenyl dioxothiophene, and the catalyst is 100:(80-120):(0.1-2), and more preferably 100:(100-120):(0.3-1).

[0019] Preferably, the molar ratio of the halotriphenylamine, the organic acid, and the base is 1:(0.3-1.2):(2.6-3.2), and more preferably 1:(0.9-1.1):(2.9-3.1).

[0020] Preferably, when the reaction system contains a ligand, the molar ratio of the catalyst to the ligand is 1:(3-5), more preferably 1:(3.5-4.5).

[0021] Preferably, the catalyst is at least one selected from palladium acetate, Hermann catalyst, tris(dibenzylacetone)dipalladium-chloroform adduct, palladium(II) diacetonitrile dichloride, tris(dibenzylacetone)dipalladium, and dimethyl(tetramethylethylenediamine)palladium.

[0022] Preferably, the ligand is at least one selected from triphenylphosphine, tris(o-methoxyphenyl)phosphine, tris(o-dimethylaminophenyl)phosphine, tris(o-methylphenyl)phosphine, and tricyclohexylphosphine tetrafluoroborate.

[0023] Preferably, the organic acid is at least one selected from pivalic acid, 1-adamantanecarboxylic acid, acetic acid, and neodecanoic acid.

[0024] Preferably, the alkali is at least one selected from potassium carbonate, cesium carbonate, and potassium trimethylacetate.

[0025] Preferably, the organic solvent is at least one selected from N,N-dimethylacetamide, N,N-dimethylformamide, toluene, tetrahydrofuran, dioxane, chlorobenzene, and xylene.

[0026] Preferably, the conditions for the polymerization reaction include: a temperature of 70-130°C and a time of 1-48 hours.

[0027] A third aspect of the present invention also provides the application of the aforementioned polytriarylamine as a hole transport material in solar cells.

[0028] A fourth aspect of the present invention provides a perovskite solar cell comprising, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and a metal electrode layer, wherein the hole transport layer is formed of the polytriarylamine described above.

[0029] By employing the above technical solution, alkenyl dioxothiophene and trihalophenylamine with specific structures are selected as polymerization monomers, and direct arylation condensation polymerization is used to synthesize polytriarylamine. This approach balances the performance and cost of polytriarylamine, resulting in low synthesis cost, high reaction efficiency, and greater efficiency and environmental friendliness. Furthermore, the polytriarylamine exhibits strong interaction with perovskite, which can improve the wettability of the perovskite precursor solution on the polytriarylamine hole transport layer film. This is of great significance for further improving the performance of perovskite solar cells and promoting their large-scale commercialization. Attached Figure Description

[0030] Figure 1These are contact angle photographs of the polyaniline derivative D1 prepared in Comparative Example 1 and the polytriarylamine A1 film prepared in Example 1;

[0031] Figure 2 This is a schematic diagram of the device structure of a perovskite solar cell.

[0032] Explanation of reference numerals in the attached figures

[0033] 1. Conductive substrate; 2. Hole transport layer; 3. Perovskite light absorption layer; 4. Electron transport layer; 5. Metal electrode layer. Detailed Implementation

[0034] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0035] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0036] The polytriarylamine of this invention contains structural units formed from alkenyl dioxythiophene and structural units formed from halotriphenylamine, wherein the alkenyl dioxythiophene is at least one of the monomers shown in formula (I-1), formula (I-2), and formula (I-3), and the halotriphenylamine is the monomer shown in formula (II).

[0037]

[0038] Among them, R1, R2, and R3 are each independently selected from H, C1-C 16 Alkyl and C1-C 16 R4, R5, and R6 are each independently selected from one of C1-C6 alkyl, C1-C6 alkoxy, and C1-C6 alkylthioyl groups; X1 and X2 are each halogens. By selecting the alkenyl dioxothiophene and the halotriphenylamine with the above structures as polymerization monomers, polyarylates can be directly arylated and polymerized into polytriarylamines, resulting in lower synthesis costs and higher reaction efficiency.

[0039] According to the polytriarylamine of the present invention, in the alkenyl dioxothiophene, preferably, R1, R2 and R3 are each independently selected from H and any one of the groups shown in formulas (1)-(4):

[0040] Where m = 1 - 11,

[0041] In a preferred embodiment, the alkenyl dioxythiophene is at least one selected from ethylene dioxythiophene, propylene dioxythiophene, and 3,4-styrene dioxythiophene. According to this preferred embodiment, the structural units formed by the alkenyl dioxythiophene in the polytriarylamine can form coordination interactions with the perovskite, improving the wettability of the perovskite precursor solution on the polymer hole transport layer, making it more suitable for perovskite solar cells.

[0042] According to the present invention, in the halogenated triphenylamine, preferably, R4, R5 and R6 are each independently selected from one of methyl, methoxy and methylthio.

[0043] In a preferred embodiment, the halogenated triphenylamine is at least one selected from N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline, N,N-bis(4-bromophenyl)-2,4,6-trimethoxybenzene, and N,N-bis(4-bromophenyl)-2,4,6-trimethylthiobenzene.

[0044] In specific embodiments, the polytriarylamine of the present invention has at least one of the structures shown in formula (III-1), formula (III-2), and formula (III-3).

[0045]

[0046] Among them, R1, R2, and R3 are each independently selected from H, C1-C 16 Alkyl and C1-C 16 R4, R5 and R6 are each independently selected from one of C1-C6 alkyl, C1-C6 alkoxy and C1-C6 alkylthio.

[0047] In the polytriarylamine described in this invention, the molar ratio of the structural unit formed by alkenyl dioxythiophene and the structural unit formed by halotriphenylamine can be (0.8-1.2):1, preferably (0.9-1.2):1, and more preferably (1-1.2):1. When the molar ratio of the two structural units is within the above range, the polytriarylamine has better wettability and performs better as a hole transport layer in perovskite solar cells, which is more conducive to further improving the performance of perovskite solar cells.

[0048] In the polytriarylamine described in this invention, preferably, the number-average molecular weight is 5000 to 30000 g / mol. In this invention, the number-average molecular weight of the polytriarylamine is determined by high-temperature gel permeation chromatography. When the molecular weight of the polytriarylamine is controlled within the above range, the wettability of the polytriarylamine is better, resulting in better performance as a hole transport layer in perovskite solar cells, and thus further improving the performance of perovskite solar cells.

[0049] The present invention also provides a method for preparing the aforementioned polytriarylamine, the method comprising: polymerizing a halotriphenylamine and an alkenyl dioxothiophene in the presence of a catalyst under an inert atmosphere.

[0050] In the method described in this invention, preferably, during the polymerization reaction, the reaction system further contains an organic acid, a base, an organic solvent, and optionally a ligand.

[0051] In the method described in this invention, the molar ratio of the halotriphenylamine, the alkenyl dioxythiophene, and the catalyst can be 100:(80-120):(0.1-2), preferably 100:(90-120):(0.2-1.5), and more preferably 100:(100-120):(0.3-1).

[0052] In the method described in this invention, the molar ratio of the halotriphenylamine, the organic acid, and the base can be 1:(0.3-1.2):(2.6-3.2), preferably 1:(0.5-1.1):(2.8-3.1), and more preferably 1:(0.9-1.1):(2.9-3.1).

[0053] In the method described in this invention, when the reaction system contains a ligand, the molar ratio of the catalyst to the ligand can be 1:(3-5), preferably 1:(3.2-4.8), and more preferably 1:(3.5-4.5).

[0054] In a preferred embodiment, the synthesis method of the polytriarylamine includes: a polymerization reaction of a halotriphenylamine and an alkenyl dioxothiophene in the presence of a catalyst, an organic acid, a base, an organic solvent, and optionally a ligand under an inert atmosphere, wherein the molar ratio of the halotriphenylamine, the alkenyl dioxothiophene, and the catalyst is 100:(100-120):(0.3-1), the molar ratio of the halotriphenylamine, the organic acid, and the base is 1:(0.9-1.1):(2.9-3.1), and when the reaction system contains a ligand, the molar ratio of the catalyst to the ligand is 1:(3.5-4.5). The polytriarylamine prepared according to this preferred embodiment has better wettability and performs better as a hole transport layer in perovskite solar cells, thus further improving the performance of perovskite solar cells.

[0055] In the method described in this invention, the inert atmosphere may be provided by nitrogen or an inert gas (such as argon).

[0056] In the method described in this invention, the alkenyl dioxythiophene is at least one of the monomers shown in formula (I-1), formula (I-2), and formula (I-3).

[0057]

[0058] Among them, R1, R2, and R3 can be independently selected from H, C1-C 16 Alkyl and C1-C 16 One of the alkoxy groups.

[0059] In a preferred embodiment, R1, R2, and R3 are each independently selected from H and any one of the groups shown in formulas (1) to (4):

[0060] Where m = 1 - 11,

[0061] More preferably, the alkenyl dioxythiophene is at least one of 3,4-ethylene dioxythiophene, 3,4-(2,2-dimethylpropenedioxy)thiophene, and 3,4-styrene dioxythiophene.

[0062] In the method described in this invention, the halotriphenylamine is a monomer represented by formula (II).

[0063]

[0064] R4, R5 and R6 can each be independently selected from one of C1-C6 alkyl, C1-C6 alkoxy and C1-C6 alkylthio, and X1 and X2 are each halogens.

[0065] In a preferred embodiment, R4, R5 and R6 are each independently selected from one of methyl, methoxy and methylthio.

[0066] More preferably, the halogenated triphenylamine is at least one selected from N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline, N,N-bis(4-bromophenyl)-2,4,6-trimethoxybenzene, and N,N-bis(4-bromophenyl)-2,4,6-trimethylthiobenzene.

[0067] In the method described in this invention, the catalyst can be a transition metal catalyst conventionally used in the art, preferably at least one of palladium acetate, Hermann catalyst, tris(dibenzylacetone)dipalladium-chloroform adduct, palladium(II) diacetonitrile, tris(dibenzylacetone)dipalladium and dimethyl(tetramethylethylenediamine)palladium.

[0068] In the method described in this invention, the ligand can be at least one selected from triphenylphosphine, tris(o-methoxyphenyl)phosphine, tris(o-dimethylaminophenyl)phosphine, tris(o-methylphenyl)phosphine, and tricyclohexylphosphine tetrafluoroborate. In the method described in this invention, the ligand acts as an auxiliary catalyst, enabling the catalyst to exert a better catalytic effect and improve reaction efficiency. Therefore, depending on the catalyst used, different ligands can be selected or no ligand may be added. In a preferred embodiment, the catalyst is tris(dibenzylacetone)dipalladium-chloroform adduct, and the ligand is tris(o-dimethylaminophenyl)phosphine; or, the catalyst is palladium acetate, and no ligand is required.

[0069] In the method described in this invention, the organic acid can be an organic acid commonly used in the art, preferably at least one of pentanoic acid, 1-adamantanecarboxylic acid, acetic acid and neodecanoic acid.

[0070] In the method described in this invention, the base is at least one selected from potassium carbonate, cesium carbonate, and potassium trimethylacetate.

[0071] In some specific embodiments, the organic acid is 1-adamantanecarboxylic acid, and the base is potassium carbonate.

[0072] In some other specific embodiments, the organic acid is pivalic acid and the base is cesium carbonate.

[0073] In some other specific embodiments, the organic acid is 1-adamantanecarboxylic acid, and the base is potassium trimethylacetate.

[0074] In the method described in this invention, the organic solvent can be an organic solvent commonly used in the art, preferably at least one of N,N-dimethylacetamide, N,N-dimethylformamide, toluene, tetrahydrofuran, dioxane, chlorobenzene and xylene, and more preferably N,N-dimethylacetamide or tetrahydrofuran.

[0075] In the method described in this invention, the conditions for the polymerization reaction include: a temperature of 70-130°C and a time of 1-48 hours. In a specific embodiment, the polymerization reaction can be carried out in a metal bath or a microwave reactor. When the polymerization reaction occurs in a metal bath, the preferred temperature is 90-120°C and the preferred time is 16-48 hours; when the polymerization reaction occurs in a microwave reactor, the preferred temperature is 70-90°C and the preferred time is 1.5-3 hours.

[0076] In the method described in this invention, after the polymerization reaction is completed, the resulting mixture is precipitated in an organic solvent to separate the solid, which is then washed and extracted using a Soxhlet extractor, and then separated and dried to obtain the final product.

[0077] The perovskite solar cell of the present invention comprises, from bottom to top, a conductive substrate 1, a hole transport layer 2, a perovskite light absorption layer 3, an electron transport layer 4, and a metal electrode layer 5, wherein the hole transport layer 2 is formed of the polytriarylamine described above. Figure 2 This is a schematic diagram of the device structure of the perovskite solar cell described in this invention.

[0078] In some specific embodiments, the fabrication process of the perovskite solar cell of the present invention includes the following steps:

[0079] (1) Place the FTO conductive glass on a polytetrafluoroethylene rack, and then put the rack into the detergent solution, conductive glass cleaning solution, deionized water and isopropanol in sequence for ultrasonic cleaning for 15-30 minutes. Then blow it dry with nitrogen and transfer it to the glove box for later use.

[0080] (2) Prepare a toluene solution from the polytriarylamine mentioned above, coat the resulting solution onto FTO conductive glass, and then transfer it to a heating stage for annealing for 5-15 minutes to obtain a light yellow transparent film.

[0081] (3) Perovskite thin films were prepared by anti-solvent method. A perovskite precursor solution with a mass ratio of PbI2:PbBr2:FAI:MABr:CsI:MACl = 851.94:12.70:283.74:3.68:22.47:18.5 was prepared by mixing N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 5:1. The perovskite precursor solution was then coated onto the hole transport layer and then transferred to a heating stage for annealing for 15-30 min to obtain a black mirror-like perovskite thin film.

[0082] (4) An electron transport layer is prepared by vapor deposition. The glass slide with the hole transport layer and perovskite layer prepared above is placed on a mask, and the vapor deposition is carried out at a vacuum level of less than 3 × 10⁻⁶. -4 Under Pa conditions, first evaporate 20 nm C. 60 Then, 8nm BCP is deposited by evaporation;

[0083] (5) Use a knife to scrape off a portion of the film obtained in step (4) to expose the FTO conductive surface, then place the film in a custom-shaped mask, in a 3×10 -4 A 100 nm thick Ag electrode was deposited under vacuum conditions of Pa to obtain a perovskite solar cell.

[0084] The following examples further illustrate the polytriarylamine, its preparation method, and its applications according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0085] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0086] Example 1

[0087] Under a nitrogen atmosphere, N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (600.00 mg, 1.35 mmol), 3,4-ethylenedioxythiophene (210.77 mg, 1.48 mmol), tris(dibenzylacetone)dipalladium-chloroform adduct (6.98 mg, 6.74 μmol), tris(o-methoxyphenyl)phosphine (9.50 mg, 26.95 μmol), and cesium carbonate (1.32 g, 4.04 mmol) were added. L) and tervaline (137.65 mg, 1.35 mmol) were dissolved in 4.5 mL of tetrahydrofuran. The mixture was then stirred in a metal bath at 100 °C for 24 hours to induce polymerization. After the reaction was complete, the resulting reaction solution was precipitated in methanol and then filtered. The collected polymer was washed and extracted sequentially with ethanol, acetone, and n-hexane in a Soxhlet extractor. After drying, 534.00 mg of a yellow-green solid was obtained, with a yield of 90%, which was polytriarylamine A1. The number-average molecular weight of polytriarylamine A1 was determined to be 18000 g / mol by high-temperature gel permeation chromatography.

[0088] Example 2

[0089] Under a nitrogen atmosphere, N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (600.00 mg, 1.35 mmol), ethylenedioxythiophene (191.61 mg, 1.35 mmol), tris(dibenzylacetone)dipalladium-chloroform adduct (4.19 mg, 4.04 μmol), tris(o-methoxyphenyl)phosphine (4.99 mg, 14.15 μmol), and cesium carbonate (1.27 g, 3.91 mmol) were added. The polymer was dissolved in 4.5 mL of tetrahydrofuran and tertivalic acid (123.88 mg, 1.21 mmol). The mixture was then stirred in a metal bath at 90 °C for 36 hours to induce polymerization. After the reaction was complete, the resulting reaction solution was precipitated in methanol and then filtered. The collected polymer was washed and extracted sequentially with ethanol, acetone, and n-hexane in a Soxhlet extractor. After drying, 507.00 mg of a yellow-green solid was obtained, with a yield of 83%, which was polytriarylamine A2. The number-average molecular weight of polytriarylamine A2 was determined to be 12000 g / mol by high-temperature gel permeation chromatography.

[0090] Example 3

[0091] Under a nitrogen atmosphere, N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (600.00 mg, 1.35 mmol), ethylenedioxythiophene (229.93 mg, 1.62 mmol), tris(dibenzylacetone)dipalladium-chloroform adduct (13.95 mg, 13.48 μmol), tris(o-methoxyphenyl)phosphine (21.37 mg, 60.65 μmol), and cesium carbonate (1.36 g, 4.18 mmol) were added. L) and tervaline (151.41 mg, 1.48 mmol) were dissolved in 4.5 mL of tetrahydrofuran. The mixture was then stirred in a metal bath at 120 °C for 16 hours to induce polymerization. After the reaction was complete, the resulting reaction solution was precipitated in methanol and then filtered. The collected polymer was washed and extracted sequentially with ethanol, acetone, and n-hexane in a Soxhlet extractor. After drying, 525.00 mg of a yellow-green solid was obtained, with a yield of 86%, which was polytriarylamine A3. The number-average molecular weight of polytriarylamine A3 was determined to be 14000 g / mol by high-temperature gel permeation chromatography.

[0092] Example 4

[0093] Polytriarylamines were prepared according to the method in Example 1, except that the amount of 3,4-ethylenedioxythiophene was changed to 1.22 mmol and 172.45 mg, respectively. A yellow-green solid of 534.00 mg was finally obtained, with a yield of 90%, which was polytriarylamine A4. The number-average molecular weight of polytriarylamine A4 was determined to be 8000 g / mol by high-temperature gel permeation chromatography.

[0094] Example 5

[0095] Under a nitrogen atmosphere, N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (600.00 mg, 1.35 mmol), 3,4-ethylenedioxythiophene (191.61 mg, 1.35 mmol), palladium acetate (3.03 mg, 13.50 μmol), potassium carbonate (465.65 mg, 3.37 mmol), and 1-adamantanecarboxylic acid (72.88 mg, 0.40 mmol) were dissolved in 4.5 mL of N,N-dimethylacetamide. The mixture was then stirred in a metal bath at 100 °C for 6 hours to induce polymerization. After the reaction was complete, the resulting reaction solution was precipitated in methanol and then filtered. The collected polymer was washed and extracted sequentially with ethanol, acetone, and n-hexane in a Soxhlet extractor. After drying, 497.00 mg of a yellow-green solid was obtained, with a yield of 81%, which was polytriarylamine A5. The number-average molecular weight of the polytriarylamine A5 was determined to be 15,000 g / mol by high-temperature gel permeation chromatography.

[0096] Example 6

[0097] Polytriarylamines were prepared according to the method in Example 5, except that the base was replaced with potassium trimethylacetate (498.41 mg, 3.51 mmol), and the reaction conditions were changed to microwave conditions at 100°C for 30 minutes, yielding 528.00 mg of a yellow-green solid with a yield of 86%, namely polytriarylamine A6. The number-average molecular weight of polytriarylamine A6 was determined to be 32000 g / mol by high-temperature gel permeation chromatography.

[0098] Example 7

[0099] Polytriarylamines were prepared according to the method in Example 1, except that the 3,4-enyldioxythiophene monomer was replaced with 3,4-(2,2-dimethylpropenedioxy)thiophene (481.10 mg, 1.48 mmol), yielding 765.22 mg of a yellow-green solid with a yield of 89%, namely polytriarylamine A7. The number-average molecular weight of polytriarylamine A7 was determined to be 22000 g / mol by high-temperature gel permeation chromatography.

[0100] Example 8

[0101] Polytriarylamines were prepared according to the method in Example 1, except that the 3,4-olefinic dioxothiophene monomer was replaced with 3,4-styrene dioxothiophene (276.15 mg, 1.48 mmol), yielding 518.58 mg of a yellow-green solid with a yield of 77%, namely polytriarylamine A8. The number-average molecular weight of polytriarylamine A8 was determined to be 9000 g / mol by high-temperature gel permeation chromatography.

[0102] Example 9

[0103] Polytriarylamines were prepared according to the method in Example 1, except that the halogenated triphenylamine monomer was replaced with N,N-bis(4-bromophenyl)-2,4,6-trimethoxybenzene, yielding 533 mg of a yellow-green solid with a yield of 87%, namely polytriarylamine A9. The number-average molecular weight of polytriarylamine A9 was determined to be 21000 g / mol by high-temperature gel permeation chromatography.

[0104] Example 10

[0105] Polytriarylamines were prepared according to the method in Example 1, except that the halotriphenylamine monomer was replaced with N,N-bis(4-bromophenyl)-2,4,6-trimethylthiobenzene, yielding 577 mg of a yellow-green solid with a yield of 93%, namely polytriarylamine A10. The number average molecular weight of polytriarylamine A10 was determined to be 26000 g / mol by high-temperature gel permeation chromatography.

[0106] Example 11

[0107] Polytriarylamines were prepared according to the method in Example 1, except that the amount of 3,4-ethylenedioxythiophene was changed to 1.08 mmol and 152.66 mg, respectively. A yellow-green solid of 472.00 mg was finally obtained, with a yield of 77%, which was polytriarylamine A11. The number-average molecular weight of this polytriarylamine A11 was determined to be 8000 g / mol by high-temperature gel permeation chromatography.

[0108] Comparative Example 1

[0109] In this comparative example, the compound shown in formula (IV) was synthesized into a polytriarylamine without alkenyl dioxythiophene units by Suzuki coupling condensation:

[0110]

[0111] The compound shown in formula (IV) was purchased from Beijing Innocare Technology Co., Ltd.

[0112] Under a nitrogen atmosphere, N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (800.00 mg, 1.80 mmol), the compound shown in formula (IV) (969.15 mg, 1.80 mmol), and tetra(triphenylphosphine)palladium (41.53 mg, 35.94 μmol) were dissolved in 14 mL of toluene and then mixed with a 2.4 M potassium carbonate solution (993.39 mg, 3 mL). The resulting mixture was stirred at 85 °C for 40 hours. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was precipitated in methanol and filtered. The collected polymer was then extracted in a Soxhlet extractor by washing with ethanol, acetone, and n-hexane in sequence. After drying, 459 mg of a pale yellow solid was obtained, with a yield of 81%, which was polytriarylamine D1.

[0113] Comparative Example 2

[0114] The compounds shown in formulas (IV) and (V) are used in this comparative example.

[0115]

[0116] The compound shown in formula (V) was purchased from Beijing Innocare Technology Co., Ltd.

[0117] Polytriarylamines containing alkenyl dioxythiophene units were prepared according to the method of Comparative Example 1, except that N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline was replaced with the same molar amount of the compound shown in formula (V), and polytriarylamine D2 was finally obtained.

[0118] Test Example 1

[0119] Thin films were prepared from polytriarylamine A1 obtained in Example 1 and polytriarylamine D1 obtained in Comparative Example 1. The solutions were dissolved in toluene to prepare solutions with a concentration of 2 mg / mL. After stirring for 8 hours, the solutions were coated using a spin coater. The solutions were dropped onto FTO conductive glass and spin-coated at 5000 rpm for 30 seconds to obtain transparent thin films of polytriarylamine A1 and polytriarylamine D1. N,N-dimethylformamide and perovskite precursor solutions were then dropped onto the polytriarylamine A1 and polytriarylamine D1 films, respectively. The contact angles of the DMF and perovskite precursor solutions on the films were obtained as follows: Figure 1 As shown.

[0120] Depend on Figure 1 It can be seen that the polytriarylamine described in this invention has a smaller contact angle with the perovskite precursor solution, which indicates better wettability and is more conducive to the spread of the perovskite precursor solution on the hole transport layer.

[0121] Test Example 2

[0122] The polytriarylamines A1-A11 prepared in Examples 1-11 and the polytriarylamines D1-D2 prepared in Comparative Examples 1-2 were used as hole transport materials to assemble perovskite solar cell devices. The fabrication steps are as follows:

[0123] (1) Cleaning the conductive substrate

[0124] Place the FTO conductive glass on a PTFE rack, and then ultrasonically clean the rack in a detergent solution, conductive glass cleaning solution, deionized water and isopropanol for 20 minutes each. Then dry it with nitrogen gas. Before use, place it in an oven at 70°C for 3 minutes and then transfer it to a glove box for later use.

[0125] (2) Preparation of hole transport layer

[0126] The polytriarylamines A1-A11 prepared in Examples 1-11 and the polytriarylamines D1-D2 prepared in Comparative Examples 1-2 were respectively mixed with toluene to prepare solutions with a concentration of 2 mg / mL. After stirring for 8 h, a film was coated using a spin coater. 40 μL of the solution was dropped onto FTO conductive glass and spin-coated at 5000 rpm for 30 s. The film was then transferred to a heating stage at 100 °C and annealed for 10 min to obtain a pale yellow transparent film.

[0127] (3) Preparation of perovskite light-absorbing layer

[0128] Perovskite thin films were prepared using an anti-solvent method. A perovskite precursor solution with a mass ratio of PbI2:PbBr2:FAI:MABr:CsI:MACl = 851.94:12.70:283.74:3.68:22.47:18.5 was prepared using a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 5:1. After stirring at 70°C for 8 hours, the solution was filtered through a filter membrane and coated using a spin coater. 100 μL of the perovskite precursor solution was dropped onto the hole transport layer and spin-coated at 4000 rpm for 35 seconds. In the last 10 seconds, 50 μL of chlorobenzene was dropped. After the spin-coating stopped, the film was transferred to a heating stage at 110°C and annealed for 20 minutes to obtain a black mirror-like perovskite thin film.

[0129] (4) Fabrication of electron transport layer

[0130] Electron transport layers were prepared by vapor deposition. A glass slide with deposited hole transport and perovskite layers was placed on a photomask, and the deposition was carried out under a vacuum of less than 3 × 10⁻⁶. -4 Under Pa conditions, first evaporate 20 nm C. 60 Then, 8nm BCP is deposited by evaporation;

[0131] (5) Fabrication of metal electrode layer

[0132] Use a knife to scrape away a portion of the film obtained in step (4) to expose the FTO conductive surface. Then place the film in a custom-shaped mask and press it into a 3×10mm diameter. -4 An Ag electrode with a thickness of 100 nm was deposited under vacuum conditions of Pa to obtain a perovskite solar cell device.

[0133] The performance of perovskite solar cell devices assembled with polytriarylamines A1-A11 prepared in Examples 1-11 and polytriarylamines D1-D2 prepared in Comparative Examples 1-2 was tested using the following methods: at 100 mW / cm 2 JV tests were conducted under simulated solar light intensity, and the specific performance parameters of the perovskite solar cell device are shown in Table 1.

[0134] Table 1

[0135]

[0136] As can be seen from the results in Table 1, the perovskite solar cells assembled using the polytriarylamine described in this invention as a hole transport material exhibit high energy conversion efficiency and short-circuit current density; specifically, the short-circuit current density can reach 24.5 mA / cm². 2The energy conversion efficiency can reach over 20%. Therefore, the polytriarylamine in this invention, by selecting alkenyl dioxothiophene and halotriphenylamine with specific structures as polymerization monomers and employing direct arylation condensation polymerization, can balance the performance and cost of polytriarylamine. It not only has low synthesis cost and high reaction efficiency, but is also more efficient and environmentally friendly. Under optimal conditions, the yield can reach over 90%. Furthermore, the synthesized polytriarylamine has a strong interaction with perovskite, which can improve the wettability of the perovskite precursor solution to the polytriarylamine hole transport layer film. Perovskite solar cells assembled using this polytriarylamine as a hole transport material also have higher energy conversion efficiency and short-circuit current density. This is of great significance for further improving the performance of perovskite solar cells and promoting their large-scale commercialization.

[0137] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polytriarylamine, characterized in that, This polytriarylamine contains structural units formed from alkenyl dioxythiophene and structural units formed from halotriphenylamine, wherein the alkenyl dioxythiophene is at least one of the monomers shown in formula (I-1), formula (I-2), and formula (I-3), and the halotriphenylamine is the monomer shown in formula (II). Among them, R1, R2, and R3 are each independently selected from H, C1-C 16 Alkyl and C1-C 16 One of the alkoxy groups; R4, R5 and R6 are each independently selected from one of C1-C6 alkyl, C1-C6 alkoxy and C1-C6 alkylthio groups; X1 and X2 are both halogens.

2. The polytriarylamine according to claim 1, characterized in that, In the alkenyldioxythiophene, R1, R2, and R3 are each independently selected from H and any one of the groups shown in formulas (1) to (4): Where m = 1 - 11, Preferably, the alkenyl dioxythiophene is at least one of 3,4-ethylene dioxythiophene, 3,4-(2,2-dimethylpropenedioxy)thiophene, and 3,4-styrene dioxythiophene.

3. The polytriarylamine according to claim 1 or 2, characterized in that, In the halotriphenylamine, R4, R5 and R6 are each independently selected from one of methyl, methoxy and methylthio; Preferably, the halogenated triphenylamine is at least one selected from N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline, N,N-bis(4-bromophenyl)-2,4,6-trimethoxybenzene, and N,N-bis(4-bromophenyl)-2,4,6-trimethylthiobenzene.

4. The polytriarylamine according to any one of claims 1-3, characterized in that, The molar ratio of the structural unit formed by alkenyl dioxythiophene to the structural unit formed by halotriphenylamine is (0.8-1.2):1, preferably (1-1.2):

1.

5. The polytriarylamine according to claim 4, characterized in that, The number-average molecular weight of the polytriarylamine is 5,000 to 30,000 g / mol.

6. A method for preparing the polytriarylamine according to any one of claims 1-5, characterized in that, The method includes: polymerizing halotriphenylamine and alkenyl dioxothiophene in the presence of a catalyst under an inert atmosphere.

7. The method according to claim 6, characterized in that, During the polymerization reaction, the reaction system also contains organic acids, bases, organic solvents, and optional ligands; Preferably, the molar ratio of the halotriphenylamine, the alkenyl dioxothiophene, and the catalyst is 100:(80-120):(0.1-2), and more preferably 100:(100-120):(0.3-1). Preferably, the molar ratio of the halotriphenylamine, the organic acid, and the base is 1:(0.3-1.2):(2.6-3.2), more preferably 1:(0.9-1.1):(2.9-3.1); Preferably, when the reaction system contains a ligand, the molar ratio of the catalyst to the ligand is 1:(3-5), more preferably 1:(3.5-4.5).

8. The method according to claim 6 or 7, characterized in that, The catalyst is at least one selected from palladium acetate, Hermann catalyst, tris(dibenzylacetone)dipalladium-chloroform adduct, palladium(II) diacetonitrile, tris(dibenzylacetone)dipalladium, and dimethyl(tetramethylethylenediamine)palladium; and / or The ligand is at least one selected from triphenylphosphine, tris(o-methoxyphenyl)phosphine, tris(o-dimethylaminophenyl)phosphine, tris(o-methylphenyl)phosphine, and tricyclohexylphosphine tetrafluoroborate; and / or The organic acid is at least one selected from pivalic acid, 1-adamantanecarboxylic acid, acetic acid, and neodecanoic acid; and / or The base is at least one selected from potassium carbonate, cesium carbonate, and potassium trimethylacetate; and / or The organic solvent is at least one selected from N,N-dimethylacetamide, N,N-dimethylformamide, toluene, tetrahydrofuran, dioxane, chlorobenzene, and xylene.

9. The method according to claim 6 or 7, characterized in that, The conditions for the polymerization reaction include: a temperature of 70-130℃ and a time of 1-48h.

10. The use of the polytriarylamine according to any one of claims 1-5 as a hole transport material in solar cells.

11. A perovskite solar cell, comprising, from bottom to top, a conductive substrate (1), a hole transport layer (2), a perovskite light-absorbing layer (3), an electron transport layer (4), and a metal electrode layer (5), wherein, characterized in that, The hole transport layer (2) is formed from the polytriarylamine as described in any one of claims 1-5.

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