A self-assembled monolayer hole transport material based on bisphosphonic acid and preparation method and application thereof
By using a self-assembled monomolecular hole transport material based on diphosphoric acid, the problems of high cost and poor interface compatibility of traditional materials have been solved, achieving high efficiency and stable performance of perovskite solar cells and promoting their commercialization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUZHOU LIWEI NEW MATERIAL TECH CO LTD
- Filing Date
- 2024-11-09
- Publication Date
- 2026-06-30
Smart Images
Figure CN119591639B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of perovskite solar cell technology, and relates to the development of interface materials for inverted perovskite solar cells. Specifically, it relates to a self-assembled monomolecular film hole transport material based on diphosphoric acid, its preparation method, and its application. Background Technology
[0002] With the continuous growth of global demand for renewable energy, solar cells, as a green energy conversion device, have received widespread attention. Perovskite solar cells, due to their excellent photoelectric conversion efficiency, simple fabrication process, and low cost, have become one of the most promising next-generation photovoltaic technologies after silicon-based solar cells. In recent years, organic-inorganic hybrid perovskite solar cells (PSCs) have made rapid progress due to their unique photoelectric properties, with the photoelectric conversion efficiency (PCE) jumping from 3.8% to 26.7%. The application of self-assembled hole transport materials in perovskite solar cells marks a significant advancement in the field of photovoltaic technology.
[0003] However, while pursuing high performance, ensuring the long-term stable operation of PSCs has become one of the major challenges facing researchers. Among them, the hole transport layer is a key component affecting device performance. Traditional HTL materials such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), although widely used, have problems such as high cost and poor compatibility with perovskite interfaces, which limit the large-scale commercialization of PSCs.
[0004] Against this backdrop, self-assembled monolayers (SAMs) have gradually come into focus as a novel class of high-density liquid crystal (HTL) materials. SAMs possess unique structural characteristics: they can be directly bonded to the substrate surface via chemical bonds to form uniform and dense films; furthermore, by carefully designing the molecular structure, the energy level matching between SAMs and perovskites can be tuned, thereby optimizing charge separation efficiency. Moreover, compared to traditional organic HTL materials, SAMs require extremely low amounts of material, which not only helps reduce production costs but also minimizes environmental impact. More importantly, appropriately selected or modified SAMs can significantly improve the operational stability of perovskite crystals (PSCs), which is crucial for advancing this technology from the laboratory to practical applications.
[0005] Therefore, exploring efficient, stable and economical self-assembled hole transport materials suitable for perovskite solar cells has become one of the current research hotspots, and is expected to provide new ideas and technical support for solving the problems encountered in the industrialization of PSCs. Summary of the Invention
[0006] To address the shortcomings of existing technologies, the present invention aims to provide a self-assembled monomolecular film hole transport material based on bisphosphonic acid. The present invention uses methoxycarbazole as the main core, alkyl chains or benzene rings as connecting units, and bisphosphonic acid as the anchoring group, which can effectively enhance the chelation with the conductive base, improve the self-assembly characteristics of the material on the substrate surface, thereby improving the perovskite film quality, suppressing non-radiative recombination between interfaces, and improving the performance and stability of the device.
[0007] This invention is achieved through the following technical solution:
[0008] A self-assembled monolayer hole transport material based on diphosphoric acid, the chemical structure of which is selected from the following structures:
[0009]
[0010] A further improvement to the present invention is as follows:
[0011] A method for preparing a self-assembled monolayer hole transport material based on bisphosphonic acid includes the following steps:
[0012] (1) The compound of formula 1 is coupled with 1,4-dibromobutane to generate intermediate 2;
[0013] (2) Intermediate 2 undergoes a substitution reaction with tetraethylmethylene diphosphonate to generate intermediate 3;
[0014] (3) Hydrolyze intermediate 3 with bromotrimethylsilane to generate target product 4;
[0015] The reaction route is shown below:
[0016]
[0017] Further, the specific process of step one is as follows: compound 1, 1,4-dibromobutane, tetrabutylammonium bromide and potassium hydroxide aqueous solution are mixed and reacted at 60-80°C for 5-8 hours to obtain intermediate compound 2; wherein, the molar ratio of compound 1, 1,4-dibromobutane, tetrabutylammonium bromide and potassium hydroxide is 1:8-10:0.01-0.03:10-12.
[0018] Furthermore, the reaction in step two is carried out under nitrogen protection, using sodium hydride as a strong base and tetrahydrofuran as a solvent, to react intermediate compound 2 with diethyl phosphite at a temperature of 0-70°C to obtain intermediate compound 3; wherein the molar ratio of intermediate compound 2, sodium hydride and tetraethylmethylene diphosphite is 1:1.5-2.0:1-2.
[0019] Furthermore, the reaction in step three is carried out under nitrogen gas protection, using 1,4-dioxane as solvent and trimethylbromosilane as hydrolysis reagent, so that intermediate compound 3 undergoes hydrolysis reaction at a temperature of 0-50°C to obtain final product 4, and methanol is used as quenching reagent after the reaction; wherein, the molar ratio of intermediate compound 3 to trimethylbromosilane is 1:5-10.
[0020] A further improvement of the present invention is as follows:
[0021] A method for preparing a self-assembled single-molecule hole transport material based on diphosphoric acid, characterized by comprising the following steps:
[0022] (1) The compound of formula 1 is coupled with 1,3-dibromo-5-iodobenzene to generate intermediate 5;
[0023] (2) Intermediate 5 undergoes a substitution reaction with diethyl phosphite to generate intermediate 6;
[0024] (3) Hydrolyze intermediate 6 with bromotrimethylsilane to generate target product 7;
[0025] The reaction route is shown below:
[0026]
[0027] Further, the specific process of step one is as follows: compound 1, 1,3-dibromo-5-iodobenzene, cuprous iodide, 18-crown-6 and potassium carbonate are dissolved in N,N-dimethylpropenylurea and refluxed under a nitrogen atmosphere to obtain intermediate compound 5; wherein, the molar ratio of compound 1, 1,3-dibromo-5-iodobenzene, cuprous iodide, 18-crown-6 and potassium carbonate is 1:1~3:0.1~0.2:0.05~0.1:2~6.
[0028] Furthermore, the specific process of step two is as follows: intermediate 5, diethyl phosphite, palladium acetate, potassium acetate, and dppf are dissolved in 1,4-dioxane and heated under reflux to obtain intermediate compound 6, wherein the molar ratio of compound 5, diethyl phosphite, palladium acetate, potassium acetate, and dppf is 1:30-40:0.05-0.15:4-8:0.1-0.5.
[0029] Furthermore, step three is carried out under nitrogen gas protection, using 1,4-dioxane as solvent and trimethylbromosilane as hydrolysis reagent, to hydrolyze intermediate compound 6 at a temperature of 0-50°C to obtain final product 7, and methanol is used as quenching reagent after the reaction; wherein, the molar ratio of intermediate compound 6 to trimethylbromosilane is 1:10-30.
[0030] A further improvement to the present invention is as follows:
[0031] The above-mentioned application of a self-assembled single-molecule hole transport material based on diphosphoric acid in inverted perovskite solar cells.
[0032] The beneficial effects of this invention are as follows:
[0033] 1. The present invention provides a self-assembled monolayer hole transport material based on a bisphosphonate anchoring group, with methoxycarbazole as the base and bisphosphonate as the anchoring group. The introduction of bisphosphonate can effectively enhance the chelation between the material and the conductive base, which helps to achieve complete coverage and firm bonding of the self-assembled monolayer hole transport material on the substrate surface, thereby improving interface stability and reducing non-radiative recombination at the interface.
[0034] 2. Using methoxycarbazole as the parent core, the molecular dipole and interfacial properties are modulated to improve the photovoltaic performance of the material. Simultaneously, the molecular stereoconfiguration and energy level matching are optimized by controlling the electronic and spatial effects of alkyl chains or benzene ring connecting units.
[0035] 3. When the self-assembled monolayer provided by this invention is applied to an inverted perovskite solar cell, the short-circuit photocurrent density of the solar cell reaches 25.64 mA / cm². -2 With an open-circuit voltage of 1.145V, a fill factor (FF) of 0.8407, and a photoelectric conversion efficiency of 24.7%, it has practical significance for improving the efficiency of perovskite solar cells. Attached Figure Description
[0036] Figure 1 The hole transport material 4 prepared in Example 1 1 H NMR spectrum;
[0037] Figure 2 The hole transport material 7 prepared in Example 2 1 H NMR spectrum;
[0038] Figure 3 JV curves for inverted perovskite solar cells prepared by self-assembling a monolayer (4);
[0039] Figure 4 JV curves for inverted perovskite solar cells prepared by self-assembling a monolayer (e.g., 7). Detailed Implementation
[0040] The present invention will now be described in detail with reference to specific embodiments.
[0041] Example 1: Synthesis of Alkyl-Chain Diphosphate Hole Transport Material 4
[0042]
[0043] Step 1:
[0044] Compound 1 (5.0 g, 22.02 mmol), tetrabutylammonium bromide (0.142 g, 0.44 mmol), 1,4-dibromobutane (24 ml, 197.86 mmol), and 50% potassium hydroxide aqueous solution (13.55 g, 241.96 mmol) were added to a 100 ml double-necked flask. The flask was connected to a reflux apparatus and heated to reflux. After the reaction was monitored by thin-layer chromatography until complete, the heating was turned off, and the reaction was allowed to cool to room temperature. The reaction was then quenched with an appropriate amount of water. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate or anhydrous magnesium sulfate, and then 1,4-dibromobutane was removed by vacuum distillation. Finally, the concentrated mixture was purified by silica gel column chromatography (eluent: PE / DCM = 5:1, v / v). The purified product was 6.4 g of white solid, with a yield of 80.3%.
[0045] Step Two:
[0046] Under nitrogen protection, 20 mL of tetrahydrofuran, tetraethylmethylene diphosphate (2.17 g 7.52 mmol), and sodium hydride (0.33 g 13.75 mmol) were added sequentially to a 100 mL two-necked flask. Then, compound 1 (3 g 8.3 mmol) dissolved in tetrahydrofuran was slowly added dropwise. The reaction mixture was heated to reflux for 24 h. After cooling to room temperature, the reaction was quenched with an appropriate amount of water. Extraction with ethyl acetate was repeated three times. The extract was dried over anhydrous magnesium sulfate and filtered. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by column chromatography (eluent: PE / EA = 10:1, v / v) to give 3.3 g of a pale yellow oil, with a yield of 70%. 1 HNMR(400MHz,DMSO-d6)δ7.51(d,J=2.4Hz,2H),7.33–7.17(m,2H),7.08(dd,J=8.8,2.5Hz,2H),4.10(qd,J=6.9,1.4Hz,1 0H),3.92(s,6H),3.86(s,1H),2.26–2.10(m,2H),1.90–1.78(m,2H),1.60(dd,J=9.5,5.0Hz,2H),1.26(t,J=7.0Hz,12H).
[0047] Step 3:
[0048] Under nitrogen protection, compound 3 (3.9 g, 1.54 mmol) was added to a 100 mL two-necked flask, and a reflux purging apparatus was connected. Nitrogen was purged three times using a double-row tube, followed by dissolution with 1,4-dioxane. Trimethylbromosilane (20 mL, 40.36 mmol) was slowly added dropwise in an ice bath, and the mixture was stirred at room temperature for 24 h. The reaction was quenched with 20 mL of anhydrous methanol and stirred for 3 h. Finally, 300 mL of deionized water was added and the mixture was stirred for 24 h. The reaction solution was filtered and washed with water to give 2.0 g of a white solid, with a yield of 64%. 1 H NMR (400MHz, DMSO) δ7.71(d,J=2.5Hz,2H),7.43(d,J=8.9Hz,2H),7.04(dd,J=8.9,2.5Hz,2H),4. 26(t,J=7.2Hz,2H),3.85(s,6H),1.86–1.75(m,2H),1.68(d,J=7.4Hz,3H),1.57(d,J=7.2Hz,2H).
[0049] Example 2: Synthesis of benzene ring diphosphoric acid hole transport material 7
[0050]
[0051] Step 1:
[0052] Under nitrogen protection, compound 1 (2 g 8.81 mmol), 1,3-dibromo-5-iodobenzene (6.43 g 17.8 mmol), cuprous iodide (0.25 g 1.31 mmol), 18-crown-6 (0.18 g 0.68 mmol), and potassium carbonate (4.87 g 35.23 mmol) were added sequentially to a 100 mL two-necked flask. The reflux apparatus was connected, and nitrogen was purged three times using a double-row tube. The reaction mixture was then dissolved in DMPU and refluxed for 12 h. After cooling to room temperature, the reaction was quenched with water. Extraction with ethyl acetate was repeated three times, followed by drying with anhydrous magnesium sulfate and filtration. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by column chromatography (eluent: PE / DCM = 10:1, v / v) to give 3 g of a pale yellow solid, with a yield of 75%. 1 H NMR (400MHz, CDCl3) δ7.93–7.80(m,1H),7.76–7.64(m,4H),7.33(dt,J=8.9,5.7Hz,2H),7.14–6.98(m,2H),3.95(s,6H).
[0053] Step Two:
[0054] Under nitrogen protection, compound 5 (2 g 4.35 mmol), palladium acetate (0.01 g 4.08 mmol), potassium acetate (2.56 g 26.08 mmol), and dppf (0.46 g 0.86 mmol) were added sequentially to a 100 mL two-necked flask. The reflux apparatus was connected, and nitrogen was purged three times using a double-row tube. The mixture was then dissolved in 1,4-dioxane, followed by dropwise addition of diethyl phosphite. The reaction mixture was heated under reflux for 12 h. After cooling to room temperature, the reaction was quenched with a suitable amount of water. Extraction with ethyl acetate was repeated three times, followed by drying with anhydrous magnesium sulfate and filtration. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was separated by column chromatography (eluent: PE / DCM = 10:1, v / v) to give 1.87 g of a pale yellow solid, with a yield of 75%. 1 HNMR(400MHz, CDCl3)δ8.30–8.12(m,3H),7.54(s,2H),7.39–7.27(m,2H),7.05 (d,J=8.9Hz,2H),4.40–4.08(m,8H),3.95(t,J=1.5Hz,6H),1.54–1.18(m,12H).
[0055] Step 3:
[0056] Under nitrogen protection, compound 51 (1.95 g, 3.35 mmol) was added sequentially to a 100 mL two-necked flask. A reflux reflux apparatus was connected, and nitrogen was purged three times using a double-row tube. The mixture was then dissolved in 1,4-dioxane. Trimethylbromosilane (9 mL, 69.4 mmol) was slowly added dropwise under ice bath conditions, and the mixture was stirred at room temperature for 24 h. The reaction was quenched with 20 mL of anhydrous methanol, and the mixture was stirred for 3 h. Finally, 300 mL of deionized water was added, and the mixture was stirred for 24 h. The reaction solution was filtered and washed with water to give 1.4 g of a yellow solid, with a yield of 89.7%. 1 HNMR (400MHz, DMSO) δ8.12–8.00(m,1H),7.99–7.80(m,4H),7.31(d,J=8.9Hz,2H),7.08(dd,J=8.9,2.6Hz,2H),3.89(s,6H).
[0057] Example 3:
[0058] Perovskite solar cells were fabricated using the self-assembled monolayer compound 4 prepared in Example 1, according to the literature G. Qu; S. Cai; Y. Qiao; et al. Joule, 2024, 8, 2123-2134. The test light source was AM 1.5 (solarsimulator-Oriel 91160-1000, 300W), and data acquisition was performed using a Keithley 2400 digital source meter. The test results are shown below. Figure 3 The short-circuit photocurrent density of the battery device reaches 25.60 mA cm⁻², the open-circuit voltage is 1.144 V, the fill factor (FF) is 0.8292, and the photoelectric conversion efficiency reaches 24.3%.
[0059] Example 4:
[0060] Perovskite solar cells were fabricated using the self-assembled monolayer compound 7 prepared in Example 2, according to the literature G. Qu; S. Cai; Y. Qiao; et al. Joule, 2024, 8, 2123-2134. The test light source was AM 1.5 (solarsimulator-Oriel 91160-1000, 300W), and data acquisition was performed using a Keithley 2400 digital source meter. The test results are shown below. Figure 3 The short-circuit photocurrent density of the battery device reached 25.64 mA cm⁻², the open-circuit voltage was 1.145 V, the fill factor (FF) was 0.8407, and the photoelectric conversion efficiency reached 24.7%.
[0061] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A bisphosphonic acid-based self-assembled monolayer hole transport material, characterized in that, The chemical structural formula is selected from the following structures:
2. The method for preparing a self-assembled monolayer hole transport material based on bisphosphonic acid as described in claim 1, characterized in that, Includes the following steps: (1) The compound of formula 1 is coupled with 1,4-dibromobutane to generate intermediate 2; (2) Intermediate 2 undergoes a substitution reaction with tetraethylmethylene diphosphonate to generate intermediate 3; (3) Hydrolyze intermediate 3 with bromotrimethylsilane to generate target product 4; The reaction route is shown below:
3. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid as described in claim 1, characterized in that, Includes the following steps: (1) The compound of formula 1 is coupled with 1,3-dibromo-5-iodobenzene to generate intermediate 5; (2) Intermediate 5 undergoes a substitution reaction with diethyl phosphite to generate intermediate 6; (3) Hydrolyze intermediate 6 with bromotrimethylsilane to generate target product 7; The reaction route is shown below:
4. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 2, characterized in that: The specific process of step one is as follows: Compound 1, 1,4-dibromobutane, tetrabutylammonium bromide and potassium hydroxide aqueous solution are mixed and reacted at 60-80°C for 5-8 hours to obtain intermediate compound 2; wherein, the molar ratio of compound 1, 1,4-dibromobutane, tetrabutylammonium bromide and potassium hydroxide is 1:8-10:0.01-0.03:10-12.
5. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 2, characterized in that: The reaction in step two is carried out under nitrogen protection, using sodium hydride as a strong base and tetrahydrofuran as a solvent, to react intermediate compound 2 with tetraethylmethylene diphosphate at a temperature of 0-70°C to obtain intermediate compound 3; wherein the molar ratio of intermediate compound 2, sodium hydride and tetraethylmethylene diphosphate is 1:1.5-2.0:1-2.
6. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 2, characterized in that: The reaction in step three is carried out under nitrogen protection, using 1,4-dioxane as solvent and trimethylbromosilane as hydrolysis reagent, to hydrolyze intermediate compound 3 at a temperature of 0-50°C to obtain final product 4. Methanol is used as quenching reagent after the reaction. The molar ratio of intermediate compound 3 to trimethylbromosilane is 1:5-10.
7. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 3, characterized in that: The specific process of step one is as follows: compound 1, 1,3-dibromo-5-iodobenzene, cuprous iodide, 18-crown-6 and potassium carbonate are dissolved in N,N-dimethylpropenylurea and refluxed under a nitrogen atmosphere to obtain intermediate compound 5; wherein, the molar ratio of compound 1, 1,3-dibromo-5-iodobenzene, cuprous iodide, 18-crown-6 and potassium carbonate is 1:1~3:0.1~0.2:0.05~0.1:2~6.
8. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 3, characterized in that: The specific process of step two is as follows: intermediate 5, diethyl phosphite, palladium acetate, potassium acetate and dppf are dissolved in 1,4-dioxane and heated under reflux to obtain intermediate compound 6, wherein the molar ratio of compound 5, diethyl phosphite, palladium acetate, potassium acetate and dppf is 1:30-40:0.05-0.15:4-8:0.1-0.
5.
9. The method for preparing a self-assembled monomolecular hole transport material based on bisphosphonic acid according to claim 3, characterized in that: Step three is carried out under nitrogen protection, using 1,4-dioxane as solvent and trimethylbromosilane as hydrolysis reagent, to hydrolyze intermediate compound 6 at a temperature of 0-50°C to obtain final product 7. Methanol is used as quenching reagent after the reaction. The molar ratio of intermediate compound 6 to trimethylbromosilane is 1:10-30.
10. Use of a self-assembled monolayer hole transporting material based on bisphosphonic acid in inverted structure perovskite solar cells according to claim 1.