Phosphoric acid carbazole-based material, method for preparing the same, and use thereof

Abstract

The application provides a carbazole phosphate material, a preparation method and application thereof. The carbazole phosphate material has a structure shown in a general formula (I), wherein A is O or S. The application uses carbazole phosphate as a main structure, and introduces a pyridine group therein to adjust photophysical, electrochemical and photovoltaic properties. The carbazole phosphate hole transport material has good solubility, film forming property, high hole mobility and energy levels matched with perovskite. When the material is used as a non-doped hole transport material in a perovskite solar cell, a good photoelectric conversion efficiency can be obtained, and low-cost, high-performance, stable and large-area perovskite solar cell application is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology, in particular to a phosphoric acid carbazole material, a preparation method and application thereof. BACKGROUND

[0002] Perovskite solar cells (PSCs) are devices that use perovskite-type organic metal halide semiconductors as light-absorbing materials to directly convert light energy into electrical energy through photovoltaic effect. Among them, the transverse structure of PSCs shows great potential in commercial applications. The hole transport layer is an important component of perovskite solar cells, and the continuous development of new hole transport materials (HTMs) is a key factor in preparing high-efficiency and stable perovskite solar cells. Polymer hole transport materials have excellent film-forming properties and solvent resistance, and are suitable for low-cost printing technology, which has great potential in realizing large-area transverse perovskite solar cell preparation.

[0003] In transverse perovskite solar cells, hole transport materials, as important transport layer materials between the perovskite layer and the transparent electrode, not only responsible for the extraction and transmission of holes, and block the flow of electrons, but also directly affect the crystallization and film-forming properties of perovskite, and play a decisive role in improving the performance of the battery and realizing large-scale commercial application.

[0004] At present, the HTMs in perovskite solar cells are mainly divided into three categories: inorganic hole transport materials, organic small molecule hole transport materials and organic polymer hole transport materials. Small molecule HTMs have a clear structure and molecular weight, and can be roughly divided into three categories according to the spatial structure: linear structure, spiro structure and star structure, and can also be divided into dithienopyrrole type, triphenylamine type, carbazole type, difluorene type and thiophene type according to different groups contained in the molecular structure. Small molecule HTMs have become the most common HTMs in perovskite solar cells due to their advantages such as variety of synthesis products, adjustable characteristics, high purity and easy solution processing. However, due to the inherent defects of small molecule HTMs, it has brought obstacles to the large-scale commercialization of PSCs. SUMMARY

[0005] The main purpose of the present application is to provide a phosphoric acid carbazole material, a preparation method and application thereof, to solve the problems of large structural rigidity, poor film-forming performance, poor structural stability and high doping cost of small molecule hole transport materials in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a phosphoric acid carbazole material is provided, which has a structure shown in general formula (I):

[0007] Wherein, A is O or S.

[0008] According to another aspect of the present invention, a method for preparing the above-described carbazole phosphate material is provided. The preparation method is carried out under an inert gas atmosphere and includes the following steps: Step S1, ... A first palladium catalyst and a first base are mixed and dissolved in a first solvent to undergo a first coupling reaction, yielding... Where A is O or S; Step S2, Dibromobutane, a substitution catalyst, and a second base are mixed and subjected to a first nucleophilic substitution reaction to obtain... Step S3, will A mixture of triethyl phosphite undergoes a second nucleophilic substitution reaction to yield... Step S4, will The second palladium catalyst and the third base are mixed and dissolved in the second solvent to carry out the second coupling reaction, yielding... Step S5, will Trimethylsilyl bromide and 1,4-dioxane were mixed and subjected to a pre-hydrolysis reaction to obtain a solid product; the solid product was dissolved in methanol and water was added dropwise to carry out a hydrolysis reaction to obtain...

[0009]

[0010] Further, in step S1, the first palladium catalyst comprises tris(dibenzylacetone)dipalladium and 1,1'-bis(diphenylphosphine)ferrocene ligand, with a molar ratio of 1:(0.8–1.2); and / or and The molar ratio is 1:(1.0~1.1); and / or The molar ratio of the first palladium catalyst to the first palladium catalyst is 1:(0.08~0.12); and / or the reaction temperature of the first coupling reaction is 100~140℃, and the reaction time is 10~14h.

[0011] Further, in step S2, the substituted catalyst includes tetrabutylammonium bromide; and / or The ratio of the amount of substance to the volume of dibromobutane is (2.5–3.0 mmol): 20 mL; and / or The molar ratio of the catalyst to the substituted catalyst is 1:(0.08~0.12); and / or the reaction temperature for the first nucleophilic substitution reaction is 60~70℃, and the reaction time is 10~14h.

[0012] Furthermore, in step S3, The ratio of the amount of substance to the volume of triethyl phosphite is (2.8–3.2 mmol):10 mL; and / or the reaction temperature for the second nucleophilic substitution reaction is 130–160 °C, and the reaction time is 10–14 h.

[0013] Further, in step S4, the second palladium catalyst comprises palladium acetate and tri-tert-butylphosphine ligand, and the molar ratio of the two is 1:(0.8-1.2); and / or with a molar ratio of 1:(2.0-2.4); and / or a molar ratio of 1:(0.08-0.12) with the second palladium catalyst; and / or the reaction temperature of the second coupling reaction is 65-85℃, and the reaction time is 6-15h.

[0014] Further, in step S5, a molar ratio of 1:(9.5-10.5) with trimethylsilyl bromide; and / or a ratio of the amount of substance of the two to the volume of 1,4-dioxane is (1.8-2.2mmol):10mL; and / or the temperature of the hydrolysis pre-reaction is 20-30℃, and the time is 10-14h; the temperature of the hydrolysis reaction is 20-30℃, and the time is 10-14h.

[0015] Further, the inert gas comprises nitrogen and / or argon; and / or the first base, the second base and the third base independently comprise one or more of sodium tert-butoxide, potassium hydroxide, potassium carbonate and sodium carbonate; and / or the first solvent comprises toluene and / or tetrahydrofuran; and / or the second solvent comprises toluene and isopropyl alcohol, and the weight ratio of the two is 1:(6-10).

[0016] According to another aspect of the present application, a hole transport layer is provided, comprising the above-mentioned phosphoric acid carbazole material of the present application, or comprising the phosphoric acid carbazole material obtained by using the above-mentioned preparation method of the present application.

[0017] According to another aspect of the present application, a perovskite solar cell is provided, comprising the above-mentioned hole transport layer of the present application.

[0018] By using the technical solution of the present application, phosphoric acid carbazole is used as the main structure, which has the ability to uniformly coat on rough surfaces, high hole extraction selectivity, and low interface electron trap density, and therefore can be used as an excellent hole selective contact layer. At the same time, pyridine groups are introduced therein to adjust the photophysical, electrochemical and photovoltaic properties, and the surface wettability of the perovskite precursor solution is improved, thereby inducing the growth of high-quality perovskite thin films; the N atoms in pyridine and the amino groups with lone pair electrons can form coordination bonds with uncoordinated Pb 2+ ions in perovskite thin films, effectively reducing the defect density in perovskite thin films; the introduction of pyridine groups can also enhance the hole mobility, improve the energy level, thereby improving the interface charge extraction and reducing the interface V ocLoss; by pyridine at the interface to produce excellent inherent thermal / light stability and stronger interaction to release interface stress, so that the thermal performance and running stability of perovskite solar cells are improved. The phosphoric acid carbazole hole transport material has good solubility, film forming property, high hole mobility and energy level matching with perovskite. When it is applied to perovskite solar cells as a non-doped hole transport material, better photoelectric conversion efficiency can be obtained, and low-cost, high-performance, stable and large-area perovskite solar cell application can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application and explanations thereof serve to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0020] Figure 1 A nuclear magnetic spectrum of a phosphoric acid carbazole material according to Embodiment 1 of the application is shown;

[0021] Figure 2 A nuclear magnetic spectrum of a phosphoric acid carbazole material according to Embodiment 2 of the application is shown;

[0022] Figure 3 A schematic diagram of a perovskite solar cell structure according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0023] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] Unless otherwise specified, "solution" in the present application refers to an aqueous solution, "room temperature" refers to 20-30℃, and "overnight" refers to 12h.

[0025] As described in the background art of the present application, there are problems of large structural rigidity, poor film forming property, poor structural stability, and high doping cost of small molecule hole transport materials in the prior art. In order to solve the above problems, in a typical embodiment of the present application, a phosphoric acid carbazole material is provided, which has a structure shown in general formula (I):

[0026] In the formula, A is O or S.

[0027] The inventors unexpectedly found during the research that due to the rigid structure of small molecule HTMs, the tolerance of perovskite precursor solution is low, the film produced by small molecule HTMs always has pinhole morphological defects, the morphology is unstable under external stimulation, and many small molecule HTMs need to add dopants, which also brings obstacles to the large-scale commercialization of PSCs.

[0028] Currently, some of the most promising inverted structure perovskite solar cells are prepared using self-assembled monolayers (SAMs) containing carbazolyl phosphonic acid (PA), such as [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), and [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz). They can be used as excellent pore-selective contact layers, but the structure and performance still need to be improved.

[0029] The present application uses carbazolyl phosphonic acid as the main structure, which has the ability to uniformly coat rough surfaces and high pore extraction selectivity, as well as low interface electron trap density, and can therefore be used as an excellent pore-selective contact layer. At the same time, pyridine groups are introduced to adjust the photophysical, electrochemical, and photovoltaic properties, showing improved surface wettability of the perovskite precursor solution, thereby inducing the growth of high-quality perovskite thin films; the N atoms in pyridine and the amino groups with lone pair electrons can form coordination bond ions with uncoordinated Pb 2+ in the perovskite, effectively reducing the defect density in the perovskite thin film; the introduction of pyridine groups can also enhance the hole mobility, improve the energy level, thereby improving the interface charge extraction and reducing the interface V oc loss; by generating excellent intrinsic thermal / light stability and stronger interactions at the interface to release interface stress, the thermal performance and operating stability of the perovskite solar cell are improved.

[0030] The carbazolyl phosphonic acid hole transport material of the present application has good solubility, film-forming property, high hole mobility, and energy levels matching the perovskite, and when used as a non-doped hole transport material in a perovskite solar cell, a good photoelectric conversion efficiency can be obtained, realizing low-cost, high-performance, stable, and large-area perovskite solar cell applications

[0031] In another typical embodiment of the present application, a preparation method of the above-mentioned carbazolyl phosphonic acid material of the present application is also provided, which is carried out under inert gas protection and includes the following steps: step S1, mixing and dissolving a first palladium catalyst and a first base in a first solvent to perform a first coupling reaction to obtain wherein A is O or S; step S2, mixing dibromobutane, a substituted catalyst, and a second base to perform a first nucleophilic substitution reaction to obtain step S3, mixing triethyl phosphite to perform a second nucleophilic substitution reaction to obtain step S4, mixing a third base to perform a third nucleophilic substitution reaction to obtain step S5, mixing a fourth base to perform a fourth nucleophilic substitution reaction to obtain step S6, mixing a fifth base to perform a fifth nucleophilic substitution reaction to obtain step S7, mixing a sixth base to perform a sixth nucleophilic substitution reaction to obtain The second palladium catalyst and the third base are mixed and dissolved in the second solvent to perform a second coupling reaction to obtain Step S5, the Trimethylsilyl bromide and 1,4-dioxane are mixed to perform a hydrolysis pre-reaction to obtain a solid product; the solid product is dissolved in methanol and water is added dropwise to perform a hydrolysis reaction to obtain

[0032]

[0033] Specifically, the present application first performs The first palladium catalyst and the first base are mixed and dissolved in the first solvent to perform a C-N coupling reaction, i.e., a Buchwald-Hartwing coupling reaction, of an amine and an aryl halide under basic conditions and palladium catalysis to obtain

[0034] Secondly, the Dibromobutane, a substituted catalyst and a second base are mixed to perform a nucleophilic substitution under basic conditions, and dibromobutane to obtain

[0035] Subsequently, the Triethyl phosphite is mixed to perform a second nucleophilic substitution reaction, which undergoes two SN2 reactions in total: in the first step, triethyl phosphite performs an SN2 reaction with to generate a phosphonium salt; in the second step, bromide ions of the phosphonium salt perform an SN2 nucleophilic substitution with an ester alkyl group, which is accompanied by the breaking of a C-O bond and the formation of P=O, to finally obtain

[0036] Then, the The second palladium catalyst and the third base are mixed and dissolved in the second solvent to perform a Buchwald-Hartwing coupling reaction of an imine and an aryl halide under basic conditions and palladium catalysis to obtain

[0037] Finally, the Trimethylsilyl bromide and 1,4-dioxane are mixed to perform a hydrolysis pre-reaction to obtain a solid product; the solid product is dissolved in methanol and water is added dropwise to perform a hydrolysis reaction, the mechanism of the phosphonate hydrolysis reaction can be divided into two steps: in the first step, the oxygen atom of the phosphonate molecule accepts a proton to generate an intermediate, which is very stable; in the second step, a water molecule enters the reaction system and reacts with the intermediate to obtain

[0038] This invention introduces pyridine groups into perovskite hole transport materials (HTMs) through rational molecular engineering to adjust their photophysical, electrochemical, and photovoltaic properties. The prepared small-molecule hole transport materials have novel molecular structures, low synthesis costs, good solubility, film-forming properties, high hole mobility, and energy levels that match those of perovskites. When used as undoped hole transport materials in inverted perovskite solar cells, they achieve good photoelectric conversion efficiency. The preparation process is simple and suitable for industrial production. Furthermore, the prepared carbazole phosphate hole transport materials can be used in perovskite solar cells without any additives and are reproducible, showing promising application prospects.

[0039] The above preparation method is carried out entirely under inert gas protection, effectively avoiding the influence of oxygen and moisture in the air on the reaction, ensuring product purity and smooth reaction progress, ensuring sufficient reaction in each step, improving reaction efficiency and product yield. The preparation process is rationally designed, with clear steps and good repeatability, which is conducive to large-scale industrial production and reduces manufacturing costs. In summary, the preparation method of this invention not only ensures the high-quality synthesis of carbazole phosphate materials, but also simplifies the operation process, laying a solid foundation for the commercial application of high-performance perovskite solar cells.

[0040] In a preferred embodiment, in step S1, the first palladium catalyst comprises tris(dibenzylacetone)dipalladium and 1,1'-bis(diphenylphosphine)ferrocene ligand, with a molar ratio of 1:(0.8–1.2); and / or and The molar ratio is 1:(1.0~1.1); and / or The molar ratio of the first palladium catalyst to the first palladium catalyst is 1:(0.08~0.12); and / or the reaction temperature of the first coupling reaction is 100~140℃, and the reaction time is 10~14h.

[0041] Using the aforementioned palladium catalyst and appropriately controlling its molar ratio can further promote the CN coupling reaction, improve reaction activity, and thus increase product yield. Maintaining the molar ratio of reactants to catalyst within the above range allows for full utilization of the catalyst's active sites, reduces waste of catalytic activity, further improves reaction rate and product purity, and the efficient utilization of the catalyst also reduces preparation costs. Controlling the temperature and time of the first coupling reaction within the above range promotes complete reaction of the reactants, reduces side reactions, improves product selectivity, and is more conducive to obtaining carbazole phosphate materials with moderate structural rigidity and excellent film-forming properties.

[0042] To further promote effective contact and dissolution between reactants and improve reaction efficiency, in a preferred embodiment, in step S2, the catalyst is replaced with tetrabutylammonium bromide; and / or the ratio of the amount of substance of the compound to the volume of dibromobutane is (2.5-3.0 mmol):20 mL; and / or The molar ratio of the compound to the substituted catalyst is 1:(0.08-0.12); and / or the reaction temperature of the first nucleophilic substitution reaction is 60-70°C, and the reaction time is 10-14 h. The selection of tetrabutylammonium bromide as the substituted catalyst and the control of its addition amount can not only effectively catalyze the nucleophilic substitution reaction and improve the reaction rate, but also reduce the side reaction of the excess catalyst, improve the selectivity of the reaction, and improve the purity and yield of the product. The above temperature and time range can effectively promote the nucleophilic substitution reaction of the reactants and promote the full progress of the reaction, thereby increasing the yield of the product, and the obtained phosphoric acid carbazole material has small structural rigidity, good film-forming performance and structural stability, reduces the doping cost, and improves the practicability and economic benefit of the material.

[0043] In a preferred embodiment, in step S3, The ratio of the amount of substance of the compound to the volume of triethyl phosphite is (2.8-3.2 mmol):10 mL; and / or the reaction temperature of the second nucleophilic substitution reaction is 130-160°C, and the reaction time is 10-14 h. By setting the ratio within the above range, the contact between the reactants and the catalyst can be promoted, the efficient progress of the SN2 reaction can be promoted, and the reaction selectivity and product yield can be improved. Higher temperature is more conducive to the generation of phosphonium salt and the subsequent nucleophilic substitution of ester group, accelerates the reaction kinetics process, and significantly improves the reaction rate. At the same time, a longer reaction time can promote the full progress of the reaction, and further improve the purity and yield of the product. The above conditions also promote the softening of the molecular structure, reduce the structural rigidity of the final material, improve the film-forming performance and structural stability, reduce the doping cost that may be required in subsequent applications, and reduce the processing difficulty of the material.

[0044] For the purpose of obtaining a phosphoric acid carbazole material with small structural rigidity, good film-forming performance and high structural stability, in a preferred embodiment, in step S4, the second palladium catalyst includes palladium acetate and tri-tert-butylphosphine ligand, and the molar ratio of the two is 1:(0.8-1.2); and / or The molar ratio of the compound to the second palladium catalyst is 1:(0.08-0.12); and / or the reaction temperature of the second coupling reaction is 65-85°C, and the reaction time is 6-15 h. The molar ratio of the compound to the second palladium catalyst is 1:(0.08-0.12); and / or the reaction temperature of the second coupling reaction is 65-85°C, and the reaction time is 6-15 h.

[0045] ​By selecting palladium acetate and tri-tert-butylphosphine ligand as the second palladium catalyst, and controlling the molar ratio within a specific range, the activity and selectivity of the C-N coupling reaction can be further improved, the reaction process is accelerated, and the side reactions caused by excessive ligand are reduced, thereby significantly increasing the yield of the product. The molar ratio of the reactants is set to the above range to facilitate the full reaction and further improve the yield and purity of the reaction. Precise control of the amount of catalyst can improve the selectivity of the reaction, increase the yield of the product, and reduce unnecessary catalyst waste to further reduce costs. The reaction temperature and reaction time of the second coupling reaction in the above range can promote the full reaction.

[0046] In a preferred embodiment, in step S5, the molar ratio of the compound of formula (VII) to trimethylsilyl bromide is 1:(9.5-10.5); and / or the ratio of the amount of substance of the compound of formula (VII) to the volume of 1,4-dioxane is (1.8-2.2 mmol):10 mL; and / or the temperature of the hydrolysis pre-reaction is 20-30°C, and the time is 10-14 h; the temperature of the hydrolysis reaction is 20-30°C, and the time is 10-14 h.

[0047] The molar ratio of the reactants set to the above range can promote the effective conversion between the reactants, facilitate the uniform progress of the reaction, reduce side reactions caused by excessive reactants, and significantly improve the yield of the product. When the temperature and time of the hydrolysis pre-reaction and the hydrolysis reaction are controlled within the above range, the reaction is mild and sufficient, reducing the decomposition or structural changes of the product caused by high temperature, while ensuring the complete progress of the hydrolysis reaction and reducing the residue of unreacted substances, which has a positive effect on the structural rigidity and film-forming performance of the product. Mild hydrolysis reaction conditions also avoid the introduction of additional high-temperature processing costs, which is conducive to controlling the economy of the entire preparation process. The resulting carbazole phosphate material has good structural stability and excellent film-forming performance, and due to the mild reaction conditions, no additional dopant is needed, effectively reducing the preparation cost of the material.

[0048] To further effectively isolate oxygen and water vapor, prevent the oxidation and hydrolysis of reactants, ensure the smooth progress of the reaction, and improve the purity and yield of the product, in a preferred embodiment, the inert gas includes nitrogen and / or argon; and / or the first base, the second base, and the third base each independently includes one or more of sodium tert-butoxide, potassium hydroxide, potassium carbonate, and sodium carbonate; and / or the first solvent includes toluene and / or tetrahydrofuran; and / or the second solvent includes toluene and isopropyl alcohol, with a weight ratio of 1:(6-10). The use of the above-mentioned basic reagents not only accelerates the reaction process and improves the reaction rate, but also helps to control the pH value of the reaction, improve the reaction selectivity, reduce the generation of by-products, and thus further increase the yield of the target product, i.e., the phosphoric acid carbazole material. The above-mentioned solvents not only have good solubility, thereby improving the solubility of the reactants and promoting the full progress of the reaction, but also, due to the differences in their boiling points and polarities, help to control the temperature of the reaction system and the distribution of the reactants, ensuring the uniformity of the reaction and the quality of the reaction product, reducing the structural rigidity of the material, improving the film-forming performance and structural stability, reducing the subsequent doping costs that may be required, significantly improving the synthesis efficiency of the phosphoric acid carbazole material, ensuring the high purity and high yield of the product, and at the same time, improving the performance of the material, making it more suitable for the preparation of commercial high-performance perovskite solar cells.

[0049] For the purpose of further improving the purity of the product of each step, and further improving the structural stability, film forming property and photoelectric property of the carbazolium phosphate material, in a preferred embodiment, step S1 further comprises a first purification step of the reaction solution, which comprises: using saturated sodium chloride aqueous solution and dichloromethane in a volume ratio of (10-15): 1 to extract the organic phase, then drying with anhydrous magnesium sulfate, and then sequentially performing filtration, reduced pressure distillation, and silica gel chromatography purification; and / or step S2 further comprises a second purification step of the reaction solution, which comprises: using saturated sodium chloride aqueous solution and dichloromethane in a volume ratio of (10-15): 1 to extract the organic phase, then drying with anhydrous magnesium sulfate, and then sequentially performing filtration, reduced pressure distillation, and silica gel chromatography purification; and / or step S3 further comprises a third purification step of the reaction solution, which comprises: using saturated sodium chloride aqueous solution and dichloromethane in a volume ratio of (10-15): 1 to extract the organic phase, then drying with anhydrous magnesium sulfate, and then sequentially performing filtration, reduced pressure distillation, and finally recrystallization using alcohol and dichloromethane in a volume ratio of (15-30): 1; the alcohol is methanol or ethanol; and / or step S4 further comprises a fourth purification step of the reaction solution, which comprises: using saturated sodium chloride aqueous solution and dichloromethane in a volume ratio of (10-15): 1 to extract the organic phase, then drying with anhydrous magnesium sulfate, and then sequentially performing filtration, reduced pressure distillation, and finally recrystallization using alcohol and dichloromethane in a volume ratio of (15-30): 1; the alcohol is methanol or ethanol; and / or step S5 further comprises a fifth purification step of the reaction solution, which comprises: recrystallization using alcohol and dichloromethane in a volume ratio of (15-30): 1; the alcohol is methanol or ethanol.

[0050] In another typical embodiment of the present application, a hole transport layer is also provided, which comprises the carbazolium phosphate material described above in the present application, or comprises the carbazolium phosphate material obtained by using the preparation method described above in the present application, has a HOMO energy level matching and deeper than that of perovskite, has good mobility, is conducive to the extraction and transport of holes, and has significantly improved transport capacity.

[0051] In another typical embodiment of the present application, a perovskite solar cell is also provided, which comprises the hole transport layer described above in the present application, and has significantly improved photoelectric property. Specifically, the transverse quasi-two-dimensional perovskite solar cell device structure can be ITO glass / hole transport layer / quasi-two-dimensional perovskite / electron transport layer (PC61BM) / chromium (Cr) / gold (Au), wherein the hole transport layer is made of the carbazolium phosphate hole transport material provided in the present application. The preparation method of the transverse quasi-two-dimensional perovskite solar cell based on the carbazolium phosphate hole transport material can comprise the following steps:

[0052] (1) Cleaning: The ITO glass was cleaned by ultrasonic treatment in deionized water, acetone and ethanol for 15-20 min, respectively. Then the ITO surface was dried by N2 gun. The ITO glass was transferred into a nitrogen glove box and treated by oxygen plasma for 10-15 min.

[0053] (2) Preparation of hole transport layer: 3-15 mg of the hole transport material PACZ-OMe was dissolved in 1 mL of chlorobenzene. The solution was spin-coated on the ITO glass substrate at 4000-5000 rpm for 20-30 s, and then annealed at 90-110 °C for 10 min.

[0054] (3) Preparation of perovskite layer: The ITO / hole transport layer substrate was cooled to room temperature and preheated at 130-140 °C for 3-5 min. 50 μL of perovskite solution was spin-coated on the ITO / hole transport layer substrate at 3000-5000 rpm for 20-30 s, and then annealed at 90-100 °C for 10 min to form the perovskite layer. The perovskite solution was prepared by mixing 3-bromo-benzylammonium iodide or 3-chlorobenzylammonium iodide with methylammonium chloride and lead iodide in DMF and DMSO according to a certain molar ratio.

[0055] (4) Preparation of electron transport layer: The ITO / hole transport layer / perovskite substrate was cooled to room temperature. PC61BM was configured into a 15 mg / mL solution, and then 40 μL of the PC61BM solution was spin-coated on the ITO / hole transport layer / perovskite substrate at 1000 rpm for 30-50 s.

[0056] (5) Preparation of electrode: The substrate was placed in a vacuum evaporation box, and Cr (6 nm) and Au (80 nm) were evaporated on the PC61BM layer to obtain the desired transverse quasi-two-dimensional perovskite solar cell.

[0057] The application will be further described in detail below in conjunction with specific examples, which should not be construed as limiting the scope of the application.

[0058] Example 1

[0059] Synthesis of PACZ-OMe, the synthetic route is as follows:

[0060]

[0061] Step S1, synthesis of compound of formula (3): A flask was charged with compound of formula (1 ) (1.1 g, 4 mmol), p-anisidine (0.53 g, 4.2 mmol), Pd2(dba)3(0.18 g, 0.2 mmol), DPPF (0.1 1 g, 0.2 mmol), sodium tert-butoxide (0.38 g, 4 mmol) and toluene. The reaction was stirred at 120 °C for 12 h. The reaction mixture was extracted with DCM, dried over anhydrous magnesium sulfate and purified by column chromatography using PE:DCM 6:1 to give compound of formula (3) in 60% yield.

[0062] Step S2, synthesis of compound of formula (7): A 100 mL two-necked flask was charged with compound of formula (6) (0.88 g, 2.72 mmol), tetrabutylammonium bromide (0.32 g, 0.27 mmol) dissolved in dibromobutane (20 mL) and then 50% aqueous potassium hydroxide solution (5 mL) was added dropwise. The mixture was heated to 65 °C and then stirred overnight. The reaction was quenched with water, extracted with dichloromethane, the organic layer was combined and dried over anhydrous magnesium sulfate and then the organic solvent was removed using a rotary evaporator to give the crude product. Further purification was carried out using silica gel column chromatography with eluent petroleum ether / dichloromethane = 10 / 1 to give compound of formula (7) (0.89 g, 88% yield).

[0063] Step S3, synthesis of compound of formula (8): A 100 mL two-necked flask was charged with compound of formula (7) (1.38 g, 3.0 mmol) and triethyl phosphite (10 mL) and then the mixture was heated to 160 °C and stirred overnight under nitrogen atmosphere. The reaction was extracted with dichloromethane, the organic layer was combined and dried over anhydrous magnesium sulfate and then the organic solvent was removed using a rotary evaporator to give the crude product compound of formula (8) (1.12 g, 2.21 mmol) in 70% yield.

[0064] Step S4, synthesis of compound of formula (9): A 100 mL two-necked flask was charged with compound of formula (8) (1.06 g, 2.0 mmol), compound of formula (5) (1.39 g, 4.4 mmol) and palladium acetate (0.1 mmol), tri-tert-butylphosphine (0.1 mmol), sodium tert-butoxide (4 mmol) dissolved in a mixture of toluene:isopropanol (1 :8) and the reaction was stirred at 85 °C for 6 to 15 h. The mixture was cooled to room temperature, the isopropanol toluene mixture was removed under reduced pressure, washed with saturated sodium chloride solution and extracted with dichloromethane, dried over anhydrous magnesium sulfate, filtered and distilled under reduced pressure to give the crude product. Recrystallization with ethanol (methanol) / dichloromethane gave compound of formula (9) (1.51 g, 1.5 mmol) in 75% yield.

[0065] Step S5, synthesis of PACZ-OMe: To a 100 mL two-necked flask was added the compound of formula (5) (2.01 g, 2 mmol) in anhydrous 1,4-dioxane (10 mL) at room temperature, and trimethylsilyl bromide (3.06 g, 20 mmol) was added dropwise, followed by stirring overnight. The 1,4-dioxane was removed with a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and deionized water was added dropwise, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water to obtain the crude product. The crude product was dissolved in THF (5 mL) and reprecipitated in acetone (20 mL), and the final product was obtained by filtration as PACZ-OMe (1.61 g, yield 85%).

[0066] Example 2

[0067] Synthesis of PACZ-SMe, the synthetic route is as follows:

[0068]

[0069] Step S1, synthesis of the compound of formula (5): The compound of formula (1) (1.1 g, 4 mmol), the compound of formula (4) (0.53 g, 4.2 mmol), Pd2(dba)3(0.18 g, 0.2 mmol), DPPF (0.11 g, 0.2 mmol), sodium tert-butoxide (0.38 g, 4 mmol) and toluene were weighed into a flask and reacted at 120°C for 12 hours. Extraction was performed with DCM, dried with anhydrous magnesium sulfate, and column chromatography was performed with PE:DCM = 6:1 to obtain the compound of formula (5) with a yield of 60%.

[0070] Step S2, synthesis of the compound of formula (7): To a 100 mL two-necked flask was added the compound of formula (1) (0.88 g, 2.72 mmol) and tetrabutylammonium bromide (0.32 g, 0.27 mmol) dissolved in dibromobutane (20 mL), and then 50% aqueous potassium hydroxide solution (5 mL) was added dropwise. The mixture was heated to 65°C, and then stirred overnight. The reaction was quenched with water, extracted with dichloromethane, and the organic layer was combined and dried with anhydrous magnesium sulfate, and then the organic solvent was removed with a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography on silica gel with an eluent of petroleum ether / dichloromethane = 10 / 1 to obtain the compound of formula (7) (0.89 g, yield 88%).

[0071] Step S3, synthesis of compound of formula (8): In a 100 mL two-necked flask, compound of formula (2) (1.38 g, 3.0 mmol) and triethyl phosphite (10 mL) were added and the mixture was heated to 160 °C and stirred overnight under nitrogen atmosphere. The mixture was extracted with dichloromethane and the organic layer was dried with anhydrous magnesium sulfate and then the organic solvent was removed using a rotary evaporator to obtain the crude compound of formula (8) (1.12 g, 2.21 mmol) with a yield of 70%.

[0072] Step S4, synthesis of compound of formula (10): In a 100 mL two-necked flask, compound of formula (8) (1.06 g, 2.0 mmol), compound of formula (5) (1.46 g, 4.4 mmol) and palladium acetate (0.1 mmol), tri-tert-butylphosphine (0.1 mmol), sodium tert-butoxide (4 mmol) were dissolved in a mixture of toluene: isopropyl alcohol (1:8) and the mixture was heated to 85 °C and stirred for 6 to 15 h. The mixture was cooled to room temperature and the isopropyl alcohol toluene mixture was distilled under reduced pressure. The mixture was washed with saturated sodium chloride solution and extracted with dichloromethane, dried with anhydrous magnesium sulfate, filtered and distilled under reduced pressure to obtain the crude product. The crude product was recrystallized with ethanol (methanol) / dichloromethane to obtain the compound of formula (10) (1.55 g, 1.5 mmol) with a yield of 75%.

[0073] Step S5, synthesis of PACZ-SMe: In a 100 mL two-necked flask, compound of formula (10) (2.06 g, 2 mmol) was dissolved in anhydrous 1,4-dioxane (10 mL) at room temperature and trimethylsilyl bromide (3.06 g, 20 mmol) was added dropwise and then stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature and then deionized water was added dropwise and stirred for 12 h. The crude product was collected by filtration and washed with deionized water to obtain the crude product. The crude product was dissolved in THF (5 mL) and precipitated in acetone (20 mL) and then filtered to obtain the final product as PACZ-SMe (1.63 g, yield 85%).

[0074] Examples 3 to 4

[0075] The difference from Example 1 is that the parameters of Step S1 are different.

[0076] Table 1

[0077]

[0078] Examples 5 to 6

[0079] The difference from Example 1 is that the parameters of Step S2 are different.

[0080] Table 2

[0081]

[0082]

[0083] Examples 7 to 8

[0084] The difference from Example 1 is that the parameters of step S3 are different:

[0085] Table 3

[0086]

[0087] Examples 9 to 10

[0088] The difference from Example 1 is that the parameters of step S4 are different:

[0089] Table 4

[0090]

[0091]

[0092] Examples 11 to 12

[0093] The difference from Example 1 is that the parameters of step S5 are different:

[0094] Table 5

[0095]

[0096] To further evaluate the effect of PACZ-SMe and PACZ-OMe as HTMs on the photovoltaic performance of inverted quasi-2D RP PSCs, devices with the structure of ITO glass / polymer HTM / quasi-2D RP perovskite / PC61BM / Cr / Au were fabricated. The perovskite absorption layer was composed of (3FBA)2MA3Pb4I 13 (3FBA = 3-fluorobenzylammonium, MA = methylammonium), PC61BM was used as electron transport material (ETM), and Cr and Au were used as charge blocking layer and cathode, respectively. The PACZ phosphoric acid materials prepared in the above examples were prepared into trans- quasi two-dimensional perovskite solar cells according to the following method:

[0097] (1) Cleaning: The ITO glass sheet was ultrasonically cleaned with deionized water, acetone and ethanol for 20 minutes, then the residual solvent on the ITO surface was blown dry using a N2 air gun, and then subjected to 15 minutes of oxygen plasma treatment, followed by transferring the ITO glass sheet to a nitrogen glove box.

[0098] (2) Preparation of hole transport layer: 15 mg of the phosphoric acid carbazole hole transport material was completely dissolved in 1 mL of chlorobenzene solution, and an appropriate amount of the solution was uniformly dropped onto the ITO glass substrate, and spin-coated at 5000 rpm for 30 seconds, and then annealed at 110°C for 10 minutes;

[0099] (3) Preparation of perovskite layer: the ITO / hole transport layer substrate obtained above was cooled to room temperature, preheated at 140°C for 3-5 minutes, and 50 μL of perovskite solution was spread on the ITO / hole transport layer substrate, spin-coated at 5000 rpm for 30 seconds, and then annealed at 100°C for 10 minutes to prepare the perovskite layer. The perovskite solution was prepared by mixing 3-bromo-benzyl ammonium iodide or 3-chlorobenzyl ammonium iodide, methyl chloride amine, and lead iodide in DMF and DMSO according to a certain molar ratio;

[0100] (4) Preparation of electron transport layer: the ITO / hole transport layer / perovskite substrate obtained above was cooled to room temperature, and PC61BM was configured into a 15 mg / mL solution, and then 40 μL of the PC61BM solution was spread on the ITO / hole transport layer / perovskite substrate, and spin-coated at 1000 rpm for 30-50 seconds;

[0101] (5) Preparation of electrode: the substrate above was placed in a vacuum evaporation box, and Cr (6 nm) and Au (80 nm) were evaporated on the PC61BM layer, to obtain the required transverse quasi-two-dimensional perovskite solar cell.

[0102] The nuclear magnetic resonance spectrum of the phosphoric acid carbazole material of Example 1 is shown in Figure 1 ; the nuclear magnetic resonance spectrum of the phosphoric acid carbazole material of Example 2 is shown in Figure 2 ; and the schematic diagram of the perovskite solar cell structure of Example 1 is shown in Figure 3 .

[0103] The film-forming performance, structural stability, and photoelectric performance of the phosphoric acid carbazole materials prepared in the above examples were determined.

[0104] Test method:

[0105] Film-forming performance: PACZ-SMe and PACZ-OMe as HTM substrate are beneficial to the diffusion and growth of quasi-two-dimensional perovskite, so that a dense, uniform, and smooth perovskite film is obtained. The crystalline growth of quasi-two-dimensional perovskite thin film on different polymer HTMs was studied using AFM. The quasi-two-dimensional perovskite thin film based on PACZ-Sme or PACZ-OMe respectively exhibits a lower RMS roughness.

[0106] Structural stability: The stability of the quasi-two-dimensional perovskite solar cells with different HTMs was studied. After 1200 hours of storage in an inert environment, the percentage of the initial efficiency of the unencapsulated quasi-two-dimensional perovskite solar cells with PACZ-Sme or PACZ-OMe was tested, respectively.

[0107] Photoelectric performance: The J-V curve of the optimal device was measured under the light condition of AM 1.5G with a speed of 0.02 V s -1 , and the photovoltaic index V oc , short-circuit current density (J sc ), fill factor (FF) and photoelectric conversion efficiency (PCE) were obtained.

[0108] Among them, the full parameters of the photoelectric performance of examples 1 and 2 are shown in table 6, and the performance test results of each example are shown in table 7.

[0109] Table 6

[0110]

[0111] Table 7

[0112]

[0113]

[0114] As can be seen from the above, the phosphoric acid carbazole used in each embodiment of the present application as the host structure has the ability of uniform coating on rough surfaces, high hole extraction selectivity and low interface electron trap density, and therefore can be used as an excellent hole selective contact layer. At the same time, pyridine groups are introduced therein to adjust the photophysical, electrochemical and photovoltaic properties, and the surface wettability of the perovskite precursor solution is improved, thereby inducing the growth of high-quality perovskite thin films; the N atoms in pyridine and the amino groups with lone pair electrons can form coordination bonds with the uncoordinated Pb 2+ in the perovskite, effectively reducing the defect density in the perovskite thin film; the introduction of pyridine groups can also enhance the hole mobility, improve the energy level, thereby improving the interface charge extraction and reducing the interface V oc loss; through the pyridine, excellent intrinsic thermal / light stability and stronger interaction at the interface are generated to release the interface stress, so that the thermal performance and operating stability of the perovskite solar cell are improved. The phosphoric acid carbazole hole transport material has good solubility, film-forming property, high hole mobility and energy level matching with perovskite, and when it is used as a non-doped hole transport material in the perovskite solar cell, a better photoelectric conversion efficiency can be obtained, realizing low-cost, high-performance, stable and large-area perovskite solar cell application. In addition, it can be seen that when each process parameter is within the preferred range of the present application, the comprehensive effect is better.

[0115] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A carbazole phosphate material, characterized in that, It has the structure shown in general formula (I): （I）； Where A represents O or S.

2. The method for preparing the carbazole phosphate material according to claim 1, characterized in that, The preparation method is carried out under inert gas protection and includes the following steps: Step S1, will , A first palladium catalyst and a first base are mixed and dissolved in a first solvent to undergo a first coupling reaction, yielding... Where A is O or S; Step S2, will A mixture of dibromobutane, a substitution catalyst, and a second base undergoes a first nucleophilic substitution reaction to yield... ; Step S3, will A mixture of triethyl phosphite and [other components] undergoes a second nucleophilic substitution reaction to yield [the desired product]. ; Step S4, will , A second palladium catalyst and a third base are mixed and dissolved in a second solvent to carry out a second coupling reaction, yielding... ; Step S5, will Trimethylsilyl bromide and 1,4-dioxane were mixed and subjected to a pre-hydrolysis reaction to obtain a solid product; the solid product was dissolved in methanol and water was added dropwise to carry out a hydrolysis reaction to obtain... .

3. The preparation method according to claim 2, characterized in that, In step S1 The first palladium catalyst comprises tris(dibenzylacetone)dipalladium and 1,1'-bis(diphenylphosphine)ferrocene ligand in a molar ratio of 1:(0.8~1.2); and / or and The molar ratio is 1:(1.0~1.1); and / or The molar ratio of the palladium catalyst to the first palladium catalyst is 1:(0.08~0.12); and / or The reaction temperature of the first coupling reaction is 100~140℃, and the reaction time is 10~14h.

4. The preparation method according to claim 2, characterized in that, In step S2 The substituted catalyst comprises tetrabutylammonium bromide; and / or The ratio of the amount of substance to the volume of dibromobutane is (2.5~3.0 mmol): 20 mL; and / or The molar ratio of the substituted catalyst to the catalyst is 1:(0.08~0.12); and / or The reaction temperature for the first nucleophilic substitution reaction is 60~70℃, and the reaction time is 10~14h.

5. The preparation method according to claim 2, characterized in that, In step S3 The ratio of the amount of substance to the volume of triethyl phosphite is (2.8~3.2 mmol): 10 mL; and / or The reaction temperature for the second nucleophilic substitution reaction is 130~160℃, and the reaction time is 10~14h.

6. The preparation method according to claim 2, characterized in that, In step S4 The second palladium catalyst comprises palladium acetate and tri-tert-butylphosphine ligand in a molar ratio of 1:(0.8~1.2); and / or and The molar ratio is 1:(2.0~2.4); and / or The molar ratio of the second palladium catalyst to the second palladium catalyst is 1:(0.08~0.12); and / or The reaction temperature for the second coupling reaction is 65~85℃, and the reaction time is 6~15h.

7. The preparation method according to claim 2, characterized in that, In step S5 The molar ratio with trimethylsilyl bromide is 1:(9.5~10.5); and / or The ratio of the amount of substance to the volume of 1,4-dioxane is (1.8~2.2 mmol):10 mL; and / or The temperature of the hydrolysis pre-reaction is 20~30℃, and the time is 10~14h; the temperature of the hydrolysis reaction is 20~30℃, and the time is 10~14h.

8. The preparation method according to claim 2, characterized in that, The inert gas is selected from nitrogen or argon; and / or The first base, the second base, and the third base are each independently selected from sodium tert-butoxide, potassium hydroxide, potassium carbonate, or sodium carbonate; and / or The first solvent is selected from toluene or tetrahydrofuran; and / or The second solvent comprises toluene and isopropanol in a weight ratio of 1:(6~10).

9. A hole transport layer, characterized in that, Includes the carbazole phosphate material as described in claim 1, or includes the carbazole phosphate material obtained using the preparation method described in any one of claims 2 to 8.

10. A perovskite solar cell, characterized in that, Includes the hole transport layer as described in claim 9.

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