Pyrene-carbazole bisphosphonic acid-based self-assembled monomolecular material, and preparation method and application thereof

Abstract

The application discloses a kind of pyrene-carbazole double-phosphoric acid self-assembly monomolecular material based on it preparation method and application, belong to perovskite solar cell technical field.The material is connected with pyrene core by two carbazole units and conjugated, form large conjugated plane structure, with the following advantages:1) rigid molecular skeleton and expanded conjugated system significantly improve thermal stability and chemical stability;2) the conjugated plane of pyrene enhances intermolecular π-π stacking, promotes hole extraction and transport;3) precise control energy level matching and form dense interface layer, inhibit electron-hole recombination.As hole transport layer is applied to trans perovskite solar cell, can simultaneously improve photoelectric conversion efficiency and long-term stability, with good industrialization prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials and relates to the preparation of self-assembled monomolecular materials for inverse perovskite solar cells, and in particular to a self-assembled monomolecular material based on pyrene-carbazole diphosphate, a preparation method and an application thereof. Background Art

[0002] As the global energy transition accelerates, the development of high-efficiency, low-cost solar cell technology has become a core issue in the renewable energy sector. Compared to traditional crystalline silicon cells, which are approaching their theoretical efficiency limit, inverse perovskite solar cells (pin structure) offer enormous industrial potential thanks to their low-temperature fabrication process, excellent low-light performance, and compatibility with tandem cells. As the core functional layer of this type of cell, self-assembled monolayer materials play a decisive role in device performance: first, their molecular structure can precisely regulate the perovskite crystallization dynamics, significantly improving film quality; second, through interface energy level matching and defect passivation, they can effectively reduce non-radiative recombination losses; and third, the hydrophobic self-assembled layer can significantly enhance the environmental stability of the device. Currently, addressing the hole transport layer / perovskite interface issues unique to the inverse structure, the development of new self-assembled monolayer materials with directional dipole moments and multiple anchoring groups has become a key path to breaking through the efficiency and stability bottlenecks, and is of great significance for the commercialization of perovskite photovoltaic technology. Summary of the Invention

[0003] The present invention aims to provide a self-assembled monomolecular material based on pyrene-carbazole bisphosphate. This material utilizes a new generation of self-assembled monolayers (SAMs) as hole-selective contacts, resulting in improved thermal stability, stronger molecular stacking, and superior hole mobility compared to the conventional MeO-2PACz. The macroconjugated structure of pyrene-carbazole serves as the core, enhancing molecular stability. Simultaneously, the introduction of two phosphate anchoring groups strengthens the molecular anchoring capacity, preventing detachment during operation and improving the wettability of the perovskite on the molecular surface. This hole-transporting material exhibits a novel structure and high stability, making it a highly promising organic optoelectronic material.

[0004] The present invention is achieved through the following technical solutions:

[0005] The first aspect of the present invention provides a self-assembled monomolecular material based on pyrene-carbazole bisphosphate, which has the chemical structure shown in Formula LL01:

[0006]

[0007] The second aspect of the present invention provides a method for preparing the above-mentioned pyrene-carbazole bisphosphate self-assembled monomolecular material, comprising the following steps:

[0008] S1: Compound 1 undergoes a substitution reaction with 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole to generate compound 2;

[0009]

[0010] The molar ratio of compound 1 to 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole is 1:2-3;

[0011] S2: Compound 2 undergoes a substitution reaction with 1,4-dibromobutane to generate compound 3;

[0012]

[0013] The molar ratio of compound 2 to 1,4-dibromobutane is 1:20-60;

[0014] S3: Compound 3 undergoes a substitution reaction with triethyl phosphite to generate compound 4;

[0015]

[0016] The molar ratio of compound 3 to triethyl phosphite is 1:20-100;

[0017] S4: Compound 4 and trimethylsilyl bromide are dissolved in 1,4-dioxane to undergo a hydrolysis reaction to generate the target product, i.e., the self-assembled monolayer material LL01;

[0018]

[0019] The molar ratio of compound 4 to trimethylsilyl bromide is 1:10-30.

[0020] Furthermore, in step S1, compound 1 and 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole are dissolved in toluene, followed by addition of an aqueous potassium carbonate solution and tetrakis(triphenylphosphine)palladium. The mixture is heated to 100-120°C in an argon atmosphere and reacted for 7-8 hours to obtain compound 2. More preferably, the heating temperatures are 100°C, 110°C, and 120°C; and the reaction times are 7 hours, 7.5 hours, and 8 hours.

[0021] More preferably, the molar ratio of the compound 1 to 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole is 1:2, 1:2.5, or 1:3.

[0022] Furthermore, in step S2, compound 2 is dissolved in 1,4-dibromobutane, TBAB and potassium hydroxide aqueous solution are added, and the mixture is heated to 60-80°C and reacted for 4-8 hours to obtain compound 3. More preferably, the heating temperature is 60°C, 70°C, or 80°C; and the reaction time is 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0023] Further preferably, the molar ratio of compound 2 to 1,4-dibromobutane is 1:20, 1:30, 1:40, 1:50, or 1:60.

[0024] Furthermore, in step S3, compound 3 is reacted with triethyl phosphite at 100-200° C. under an argon atmosphere for 8-20 h to prepare compound 4, and after the reaction, the compound is separated and purified to obtain compound 4. Further preferably, the reaction temperature is 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., or 200° C.; and the reaction time is 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, or 20 h.

[0025] Further preferably, the molar ratio of compound 3 to triethyl phosphite is 1:20, 1:40, 1:60, 1:80, or 1:100.

[0026] Furthermore, in step S4, compound 4 is mixed with trimethylsilyl bromide in 1,4-dioxane and subjected to a hydrolysis reaction under an argon atmosphere. The reaction is carried out at 25-100°C for 10-24 hours. After the reaction is completed, the 1,4-dioxane is evaporated under reduced pressure, and the reaction residue is quenched by adding methanol and water in sequence, and filtered to obtain the target product LL01. Further preferably, the reaction temperature is 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, and 100°C; and the reaction time is 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, and 24 hours.

[0027] More preferably, the molar ratio of compound 4 to trimethylsilyl bromide is 1:10, 1:15, 1:20, 1:25, or 1:30.

[0028] The third aspect of the present invention is to provide the application of the above-mentioned pyrene-carbazole bisphosphate self-assembled monomolecular material in perovskite solar cells.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention aims to provide a self-assembled monomolecular material based on pyrene-carbazole bisphosphate. This material utilizes a new generation of self-assembled monolayers (SAMs) as hole-selective contacts. Compared to the conventional MeO-2PACz, it exhibits improved thermal stability, enhanced molecular stacking, and improved hole mobility. The macroconjugated structure of pyrene-carbazole serves as the core to enhance molecular stability. The introduction of two phosphate anchoring groups strengthens the molecular anchoring capacity, prevents molecular detachment during operation, and improves the wettability of the perovskite on the molecular surface. This induces the formation of a more uniform, less defective crystalline film, reducing non-radiative recombination.

[0031] 2. The application of the hole transport material provided by the present invention in inverse perovskite solar cells. The test results show that the short-circuit photocurrent density of the battery device reaches 25.11 mA cm -2 , the open circuit voltage is 1.16 V, the fill factor is 83.23%, and the photoelectric conversion efficiency reaches 24.24%, which has practical significance for improving the efficiency of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the H-NMR spectrum of the material of formula LL01 prepared in the present invention;

[0033] Figure 2 This is a thermogravimetric analysis test chart of the LL01 material prepared in the present invention;

[0034] Figure 3 This is a scanning electron microscope image of the surface of the perovskite layer based on the formula LL01 material prepared in the present invention;

[0035] Figure 4 Schematic diagram of the structure of an inverted perovskite solar cell made of the LL01 material obtained in Example 1; from bottom to top, they are ITO glass, hole transport layer, perovskite layer, C 60 layer, BCP layer, metal Ag;

[0036] Figure 5 The inverse perovskite solar cell prepared by using the LL01 material prepared by the present invention as a self-assembled monolayer hole transport material J-V curve. DETAILED DESCRIPTION

[0037] This study addresses the stability deficiencies of existing self-assembled monolayers (SAMs) such as MeO-2PACz by designing and synthesizing a novel pyrene-carbazole bisphosphate SAM. This material conjugates two carbazole units to a pyrene core, creating a stable molecular system with a large conjugated planar structure. Application of this material as a hole transport layer in inverted (pin) perovskite solar cells significantly improves photoelectric conversion efficiency and long-term stability, demonstrating promising prospects for industrial application.

[0038] Based on the above description, the present invention is introduced in detail in combination with specific embodiments. Example 1

[0039] This embodiment synthesizes a self-assembled monolayer hole transport material having the chemical structure shown in Formula LL01:

[0040]

[0041] The specific synthesis route of the self-assembled monolayer hole transport material is as follows:

[0042]

[0043]

[0044] Step S1, synthesis of compound of formula 2:

[0045] Compound 1 (2 g, 4.81 mmol) and 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole (3.24 g, 11.05 mmol) were dissolved in toluene. A 50% aqueous potassium carbonate solution (6 mL) and tetrakis(triphenylphosphine)palladium (0.56 g, 0.48 mmol) were then added. The reaction mixture was stirred and refluxed at 100°C for 8 hours, after which it was extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate and purified by column chromatography (eluent: a 1:1 mixture of petroleum ether and dichloromethane) to obtain 1.26 g of the product as a yellow solid (49% yield).

[0046] The structural characterization data of the compound of formula 2 are: 1H NMR (400 MHz, DMSO-d6) δ 11.48 (s, 2H), 8.48 (s, 2H), 8.32 (s, 2H), 8.26 (d, J = 9.3 Hz, 2H), 8.22 - 8.12 (m, 5H), 7.74 (d, J = 1.9 Hz, 4H), 7.57 (d, J = 8.1 Hz, 2H), 7.43 (ddd, J = 8.2, 7.0, 1.2 Hz, 2H), 7.17 (t, J = 7.3 Hz, 2H), 1.55 (s, 9H).

[0047] Step S2, synthesis of compound of formula 3:

[0048] Compound 2 (1.26 g, 2.37 mmol) was dissolved in 1,4-dibromobutane (25.54 g, 118.28 mmol), and then tetrabutylammonium bromide (TBAB) (0.15 g, 0.47 mmol) and 50% potassium hydroxide aqueous solution (15 mL) were added successively. The reaction system was stirred at 80 °C for 6 hours. After the reaction was completed, the reaction solution was extracted with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and then the solvent was removed by rotary evaporation under reduced pressure. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 20:3), and finally 0.68 g of yellow-green solid product was obtained (yield 33%).

[0049] The structural characterization data of compound of formula 3 are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 8.61 - 8.49 (m, 2H), 8.33 (d, J = 2.5 Hz, 2H), 8.30 - 8.20 (m, 4H), 8.20 - 8.10 (m, 3H), 7.92 - 7.75 (m, 4H), 7.70 (dd, J = 8.2, 2.3 Hz, 2H), 7.54 - 7.44 (m, 2H), 7.21 (td, J = 7.4, 1.9 Hz, 2H), 4.63 - 4.44 (m, 4H), 3.59 (td, J = 6.5, 3.0 Hz, 4H), 2.08 - 1.83 (m, 8H), 1.56 (d, J = 1.8 Hz, 7H), 1.34 - 1.15 (m, 2H).

[0050] Step S3, synthesis of compound of formula 4:

[0051] Compound 3 (0.68 g, 0.79 mmol) was dissolved in triethyl phosphite (13.16 g, 79.18 mmol). The reaction mixture was heated at 170°C for 8 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (eluent: dichloromethane / methanol = 10:1) to obtain 0.76 g of a yellow-green solid (yield 99%).

[0052] The structural characterization data of the compound of formula 4 are: 1 H NMR (400 MHz, DMSO-d6) δ 8.52 (d, J =1.7 Hz, 2H), 8.35 (s, 2H), 8.28 – 8.22 (m, 4H), 8.21 – 8.13 (m, 3H), 7.86 (d,J = 8.5 Hz, 2H), 7.79 (dd, J = 8.5, 1.7 Hz, 2H), 7.71 (d, J = 8.4 Hz, 2H), 7.54 – 7.45 (m, 2H), 7.22 (q, J = 7.0 Hz, 2H), 4.53 (t, J = 6.9 Hz, 4H), 3.96– 3.87 (m, 8H), 1.94 (q, J = 6.3, 5.3 Hz, 4H), 1.80 (dt, J = 17.5, 8.0 Hz, 4H), 1.57 (s, 12H), 1.16 (t, J = 7.0 Hz, 13H).

[0053] Step S4, synthesis of compound of formula LL01:

[0054] Under argon, compound 4 (0.76 g, 0.78 mmol) was dissolved in anhydrous 1,4-dioxane (10 ml), and trimethylsilyl bromide (TMSBr) (2.59 g, 16.92 mmol) was slowly added dropwise. The reaction system was stirred at room temperature under a nitrogen atmosphere for 24 hours. The solvent was then partially removed by distillation under reduced pressure, and the remaining liquid was dissolved in methanol (5 ml). Distilled water (50 ml) was then slowly added dropwise until the solution became turbid. The product was collected by filtration and washed with water to obtain 0.62 g of a green solid (93% yield).

[0055] The structural characterization data of the compound of formula LL01 are: 1H NMR (400 MHz, DMSO-d6) δ 8.61 – 8.41(m, 3H), 8.33 (s, 2H), 8.26 (q, J = 7.9 Hz, 4H), 8.20 – 8.12 (m, 2H), 7.91 –7.76 (m, 4H), 7.69 (d, J = 8.3 Hz, 2H), 7.49 (t, J = 7.6 Hz, 2H), 7.21 (q, J= 7.1 Hz, 2H), 4.66 – 4.37 (m, 4H), 1.94 (q, J = 7.0 Hz, 4H), 1.60 (d, J =27.0 Hz, 16H), 1.22 (d, J = 6.6 Hz, 1H). Example 2

[0056] Different from Example 1, in step S1 of this example, the mixture was heated to 110° C. in an argon atmosphere and reacted for 7 h to obtain Compound 2. Example 3

[0057] Different from Example 1 and Example 2, in step S1 of this example, the mixture was heated to 120° C. in an argon atmosphere and reacted for 7.5 h to obtain Compound 2. Example 4

[0058] Different from Example 1, in step S2 of this example, the mixture was heated to 60° C. in an argon atmosphere and reacted for 8 h to obtain compound 3. Example 5

[0059] Different from Example 1 and Example 4, in step S2 of this example, the mixture was heated to 70° C. in an argon atmosphere and reacted for 4 h to obtain Compound 3. Example 6

[0060] Different from Example 1, in step S3 of this example, the mixture was heated to 100° C. in an argon atmosphere and reacted for 20 h to obtain compound 4. Example 7

[0061] Different from Example 1 and Example 6, in step S3 of this example, the mixture was heated to 200° C. in an argon atmosphere and reacted for 15 h to obtain compound 4. Example 8

[0062] Different from Example 1, in step S4 of this example, the reaction mixture was heated to 100° C. in an argon atmosphere and reacted for 10 h to obtain the target product LL01. Example 9

[0063] Different from Example 1 and Example 9, in step S4 of this example, the target product LL01 is obtained by heating to 70° C. in an argon atmosphere and reacting for 20 h. Example 10

[0064] The hole transport material of the self-assembled monolayer (SAMs) based on tert-butylpyrene prepared in Example 1 has a hydrogen nuclear magnetic resonance spectrum as shown in FIG. Figure 1 As shown. Figure 2 The thermogravimetric analysis test chart of formula LL01 prepared by the present invention is shown, which illustrates that the thermogravimetric analysis (TGA) results of the material show that its 5% thermal decomposition temperature is as high as 405°C, showing excellent thermal stability.

[0065] Figure 3 This is a scanning electron micrograph of the surface of a perovskite layer based on Formula LL01 prepared in this invention. The simultaneous introduction of two phosphate anchoring groups enhances the molecular anchoring ability and improves the wettability of the perovskite on the molecular surface. This induces the formation of a more uniform, less defective perovskite crystal film, reducing non-radiative recombination.

[0066] The application of the compound of formula LL01 prepared in Example 1 in the preparation of perovskite solar cells is as follows Figure 4 , is a schematic diagram of the structure of the fabricated perovskite solar cell, where, from bottom to top, they are ITO glass, hole transport layer, perovskite layer, C 60 Layer, BCP layer, metal Ag. Test light source: AM 1.5 (solar simulator-Oriel 91160-1000, 300W), data acquisition using Keithley 2400 digital source meter. Test results are shown in Figure 5 The short-circuit photocurrent density of the battery device reached 25.11 mA cm -2 , the open circuit voltage is 1.16 V, the fill factor is 83.23%, and the photoelectric conversion efficiency reaches 24.24%.

[0067] The above-mentioned embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to allow people familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot limit the scope of protection of the present invention on this basis. The provided embodiments do not cover all the options of the technical solution of the present invention. It is clear that the amount ratio of the reactants, the reaction temperature and the reaction time in each step of the technical solution of the present invention can be arbitrarily selected within the scope of the technical solution of the present invention. The results can solve the technical problems of the present invention as well as achieve the same technical effects as in the above-mentioned embodiments. All equivalent conversions or modifications made according to the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-assembled monomolecular material based on pyrene-carbazole bisphosphate, characterized in that: It has the chemical structure shown in formula LL01: 。 2. The method for preparing the pyrene-carbazole bisphosphate self-assembled monomolecular material according to claim 1, characterized in that: The following steps are involved: S1: Compound 1 undergoes a substitution reaction with 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole to generate compound 2; The molar ratio of compound 1 to 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole is 1:2-3; S2: Compound 2 undergoes a substitution reaction with 1,4-dibromobutane to generate compound 3; The molar ratio of compound 2 to 1,4-dibromobutane is 1:20-60; S3: Compound 3 undergoes a substitution reaction with triethyl phosphite to generate compound 4; The molar ratio of compound 3 to triethyl phosphite is 1:20-100; S4: Compound 4 and trimethylsilyl bromide are dissolved in 1,4-dioxane, and a hydrolysis reaction occurs to generate the target product, i.e., the self-assembled monomolecular material LL01; The molar ratio of compound 4 to trimethylsilyl bromide is 1:10-30.

3. The preparation method according to claim 2, wherein: In step S1, compound 1 and 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole are dissolved in toluene, followed by addition of aqueous potassium carbonate solution and tetrakis(triphenylphosphine)palladium. The mixture is heated to 100-120°C in an argon atmosphere and reacted for 7-8 h to obtain compound 2.

4. The preparation method according to claim 2, wherein: In step S2, compound 2 is dissolved in 1,4-dibromobutane, and tetrabutylammonium bromide and potassium hydroxide aqueous solution are added, and the mixture is heated to 60-80° C. and reacted for 4-8 h to obtain compound 3.

5. The preparation method according to claim 2, wherein: In step S3, compound 3 and triethyl phosphite are heated to 100-200° C. under an argon atmosphere for 8-20 h to prepare compound 4. After the reaction, compound 4 is separated and purified.

6. The preparation method according to claim 2, wherein: In step S4, compound 4 and trimethylsilyl bromide are mixed in 1,4-dioxane, and a hydrolysis reaction is carried out under an argon atmosphere at 25-100°C for 10-24 hours. After the reaction is completed, 1,4-dioxane is evaporated under reduced pressure, and the reaction residue is quenched by adding methanol and water in sequence, and filtered to obtain the target product LL01.

7. Use of the pyrene-carbazole bisphosphate self-assembled monomolecular material according to claim 1 in perovskite solar cells.

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