Self-assembled monolayer hole transport material based on triphenylamine skeleton and preparation method and application thereof

Abstract

This invention discloses a self-assembled monolayer hole transport material based on a triphenylamine framework, its preparation method, and its applications, belonging to the field of semiconductor device technology. The hole transport material uses triphenylamine as its core framework, with a diphenylamine group introduced at one end to form an extended triphenylamine conjugated system, and a phosphonic acid group as an anchoring group at the other end. The preparation method includes reacting a brominated triphenylamine precursor with diethyl phosphite via a palladium-catalyzed carbon-phosphine bond coupling reaction to generate a phosphonate intermediate, followed by hydrolysis with trimethylbromosilane to obtain the target phosphonic acid-based self-assembled monolayer material. This invention utilizes the flexibility of the triphenylamine structure to suppress excessive intermolecular aggregation, forming a dense, uniform, pinhole-free film while simultaneously improving hole transport capability. By introducing functional substituents to regulate interface energy levels, improve molecular arrangement order, and passivate interface defects, this material can be used as a hole transport layer in inverted perovskite solar cells, showing broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, specifically relating to a self-assembled monolayer hole transport material based on a triphenylamine framework, its preparation method and application, and particularly to the application of this material in inverted perovskite solar cells. Background Technology

[0002] Perovskite solar cells have become a research hotspot in the field of renewable energy in recent years due to their excellent photoelectric conversion efficiency, low production cost, and ease of large-scale fabrication. Currently, the photoelectric conversion efficiency of perovskite solar cells fabricated in the laboratory has exceeded 27%, approaching the theoretical limit of crystalline silicon cells.

[0003] Perovskite solar cells are classified into upright (nip) and inverted (pin) structures based on the deposition order of the charge transport layer. Among these, inverted perovskite solar cells have attracted widespread attention due to their advantages such as low hysteresis, high stability, and compatibility with silicon cells in tandem fabrication. Self-assembled monolayers (SAMs), used as hole transport layers in inverted perovskite solar cells, enable interface energy level modulation, defect passivation, and perovskite crystallization control, significantly optimizing interface contact, reducing non-radiative recombination, and improving device performance.

[0004] Existing SAMs molecules typically consist of three parts: anchoring groups (such as phosphate and carboxylic acids), linking groups (such as alkyl chains), and terminal functional groups (such as aromatic groups). Ideally, SAMs should form dense, uniform, and ordered thin films on a substrate to achieve efficient charge extraction and transport. Currently, carbazole groups and alkyl chains are the most commonly used linking and terminal functional groups in SAMs, but these materials still have many problems: they are prone to molecular aggregation, leading to pinholes in the film; the molecular arrangement is loose and uneven, failing to effectively passivate interface defects; the insulating properties of alkyl chains reduce molecular packing density, disrupting the ordered arrangement and limiting hole transport efficiency; and some materials have poor wettability, affecting the crystallinity quality of subsequent perovskite layers. Therefore, developing novel high-performance SAM hole transport materials to solve the above technical problems is of great significance for further improving the efficiency and stability of inverted perovskite solar cells. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a self-assembled monolayer hole transport material based on a triphenylamine framework, its preparation method, and its applications. This invention seeks to solve the problems of severe molecular aggregation, low hole transport efficiency, and numerous interface defects in existing SAMs materials, and to provide a novel SAMs material with excellent hole transport performance, good film quality, and good interface passivation effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A self-assembled monolayer hole transport material based on a triphenylamine framework, wherein the structural formula of the self-assembled monolayer hole transport material based on a triphenylamine framework is as follows: , where X1-X 10 The groups are independently derived from hydrogen, halogen, cyano, nitro, amino, substituted or unsubstituted C1-C6 monoalkylamino, substituted or unsubstituted (di(C1-C6 alkyl))amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, or substituted or unsubstituted C1-C6 alkylthio. R1-R5 are independently derived from hydrogen, halogen, cyano, nitro, amino, substituted or unsubstituted C1-C6 monoalkylamino, substituted or unsubstituted (di(C1-C6 alkyl))amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C1-C6 alkylthio, substituted or unsubstituted C6-C 10 Aryl, substituted or unsubstituted C2-C 10 Heteroaryl groups; or R1-R5 independently form substituted or unsubstituted C6-C groups with carbon atoms attached to and adjacent to the benzene ring. 10 Aromatic rings, or carbon atoms attached to or adjacent to the benzene ring, form substituted or unsubstituted C2-C bonds. 10 Mixed fragrance ring.

[0007] Preferably, the self-assembled monolayer hole transport material based on the triphenylamine framework is selected from any of the following structures: Among them, compound S1 is tris(4-methoxyphenyl)aniline phosphonic acid; compound S2 is (4'-bromo-4,4''-dimethoxytriphenylamino)phosphonic acid; compound S3 is (4-(benzo[b]thiophen-2-yl)-4',4''-dimethoxytriphenylamino)phosphonic acid; and compound S4 is (4-(thiophen-2-yl)-4',4''-dimethoxytriphenylamino)phosphonic acid.

[0008] A method for preparing a self-assembled monolayer hole transport material based on a triphenylamine framework includes the following steps: a. Coupling reaction: The triphenylamine compound is coupled with diethyl phosphite in the presence of a palladium catalyst, ligand and base in a first organic solvent to generate a phosphonate intermediate compound; b. Hydrolysis reaction: The phosphonate intermediate compound and trimethylbromosilane are hydrolyzed in a second organic solvent. After hydrolysis, methanol is added and stirred, then deionized water is added. After the product is precipitated, it is washed with water to obtain a self-assembled monolayer hole transport material based on a triphenylamine framework.

[0009] Preferably, in step a, the palladium catalyst is palladium acetate, the ligand is 1,1'-bis(diphenylphosphine)ferrocene, and the base is potassium acetate; the molar ratio of the bromotriphenylamine compound to diethyl phosphite is 1:(1.05-1.50), and the molar equivalents of palladium acetate, 1,1'-bis(diphenylphosphine)ferrocene, and potassium acetate relative to the bromotriphenylamine compound are 0.01 eq, 0.2 eq, and 6.0 eq, respectively; the first organic solvent is 1,4-dioxane; the reaction temperature of the carbon-phosphine bond coupling reaction is 100-110℃, the reaction time is 8-12 h, and the reaction is carried out under inert gas protection.

[0010] Preferably, in step b, the molar ratio of the phosphonate intermediate compound to trimethylbromosilane is 1:(5-10); the second organic solvent is dichloromethane; the reaction temperature of the hydrolysis reaction is 25-35℃, and the reaction time is 12-24h.

[0011] Application of a self-assembled monolayer hole transport material based on a triphenylamine framework as a hole transport layer in perovskite solar cells.

[0012] An inverted perovskite solar cell includes a substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, a hole blocking layer, and a counter electrode, which are stacked sequentially; the hole transport layer is the self-assembled monolayer hole transport material based on a triphenylamine framework.

[0013] Preferably, the substrate is a glass or ITO substrate; the perovskite light-absorbing layer is composed of Cs. 0.05 MA 0.1 FA 0.85 PbI3, with a thickness of 300-500 nm, wherein MA + It is a methylammonium cation, FA + It is a formamidinium cation; the electron transport layer is [6,6]-phenyl-C 61 -Methyl butyrate or C 60 The thickness is 30-40 nm; the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline with a thickness of 10 nm; the counter electrode is a silver electrode with a thickness of 110 nm.

[0014] A method for fabricating an inverted perovskite solar cell includes the following steps: (1) Hole transport layer preparation: The self-assembled monolayer hole transport material based on the triphenylamine framework was dissolved in ethanol at a concentration of 0.5 mg / mL to obtain a precursor solution; a clean substrate treated with ozone was placed on a spin coater, the precursor solution was added dropwise for spin coating, and the hole transport layer was obtained after annealing. (2) Preparation of perovskite light-absorbing layer: The perovskite precursor solution is deposited onto the hole transport layer, spin-coated, and then annealed to obtain the perovskite light-absorbing layer; the perovskite precursor solution is Cs with a concentration of 1.5-2 mol / L. 0.05 MA 0.1 FA 0.85 PbI3 solution; (3) Functional layer preparation: An electron transport layer and a hole blocking layer are prepared sequentially on the perovskite light absorption layer; (4) Electrode preparation: Silver electrodes are deposited on the hole blocking layer to obtain the inverted perovskite solar cell.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects: 1. This invention uses triphenylamine as the core framework of SAMs. By utilizing the unique propeller-like configuration and flexibility of triphenylamine, it can undergo tilting and torsional motion, effectively suppressing π-π stacking and excessive aggregation between molecules, forming a dense, uniform, and pinhole-free high-quality self-assembled film on a glass or ITO substrate, thus avoiding charge recombination caused by film defects.

[0016] 2. The triphenylamine skeleton of the present invention has excellent hole transport performance. Its extended conjugated system can promote molecular orbital overlap and improve hole mobility. At the same time, by introducing functional substituents such as methoxy, halogen, and heteroaromatic rings on different benzene rings of triphenylamine, the energy level structure of the material can be precisely controlled to make it more compatible with the valence band energy level of perovskite, thus significantly improving the hole extraction efficiency.

[0017] 3. The preparation method of this invention is simple, has mild reaction conditions, and a high yield, making it suitable for large-scale preparation. When this material is used as a hole transport layer in an inverted perovskite solar cell, the photoelectric conversion efficiency of the device can reach 24.71%, while the open-circuit voltage, short-circuit current density, and fill factor are all significantly improved, exhibiting excellent photovoltaic performance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the inverted perovskite solar cell of the present invention; Figure 2 For inverted perovskite solar cells based on compound S1 JV Characteristic curves; Figure 3 For inverted perovskite solar cells based on compound S2 JV Characteristic curves; Figure 4 For inverted perovskite solar cells based on compound S3 JV Characteristic curves; Figure 5For inverted perovskite solar cells based on compound S4 JV Characteristic curves; Figure 6 For inverted perovskite solar cells based on the comparative material 4PACz JV Characteristic curves; Figure 7 The image shows the proton NMR spectrum of compound S1. Figure 8 The image shows the 1H NMR spectrum of compound S2. Figure 9 The image shows the proton NMR spectrum of compound S3. Figure 10 This is the 1H NMR spectrum of compound S4. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] All reagents used in this invention are commercially available analytical grade or chemically pure and are used directly without further purification. ¹H NMR spectroscopy was performed using a Bruker Avance 500MHz or 400MHz NMR spectrometer with DMSO-d6 as solvent and TMS as internal standard. Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was performed using a Bruker autoflex speed TOF / TOF mass spectrometer.

[0021] See Figures 1 to 10 As shown.

[0022] Example 1: Synthesis of compound S1 The synthetic route for compound S1 is as follows: .

[0023] 1. Synthesis of compound S1-Et: In a 250 mL double-necked flask, S1-Br (581.0 mg, 1.0 mmol), diethyl phosphite (0.18 mL, 1.4 mmol), palladium acetate (2.3 mg, 0.01 mmol), 1,1'-bis(diphenylphosphine)ferrocene (110.8 mg, 0.2 mmol), and potassium acetate (588.8 mg, 6.0 mmol) were added. 60 mL of 1,4-dioxane was added, and the mixture was purged with nitrogen three times. The mixture was then heated to 110 °C and refluxed for 12 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with 50 mL of dichloromethane, and washed successively with saturated brine (3 × 50 mL). The organic phase was dried over anhydrous MgSO4, filtered, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography (eluent: dichloromethane / ethyl acetate = 2:1, v / v) to give a yellow solid, compound S1-Et, with a mass of 402 mg and a yield of 63%. MALDI-TOF-MS (m / z): Measured value 638.24, theoretical value C 37 H 39 N2O6P: 638.25.

[0024] 2. Synthesis of compound S1 Compound S1-Et (319.0 mg, 0.5 mmol) was dissolved in 30 mL of dichloromethane, and trimethylbromosilane (0.4 mL, 3.0 mmol) was slowly added dropwise while stirring at room temperature for 12 h. The solvent was removed by vacuum distillation, and 10 mL of methanol was added to the residue, with stirring continued for 3 h. 50 mL of deionized water was added, and a pale yellow solid precipitated. The solid was filtered, and the filter cake was washed three times with deionized water and dried under vacuum to give compound S1 with a mass of 221 mg, yielding 76%. 1 ¹H NMR (500MHz, DMSO) δ: 7.75–6.35 (m, 20H), 3.76 (s, 9H). MALDI-TOF-MS (m / z): Measured value 582.11, theoretical value C 33 H 31 N2O6P: 582.19.

[0025] Example 2: Synthesis of compound S2 The synthetic route for compound S2 is as follows: .

[0026] 1. Synthesis of compound S2-Et: In a 250 mL double-necked flask, S2-Br (630.0 mg, 1.0 mmol), diethyl phosphite (0.18 mL, 1.4 mmol), palladium acetate (2.3 mg, 0.01 mmol), 1,1'-bis(diphenylphosphine)ferrocene (110.8 mg, 0.2 mmol), and potassium acetate (588.8 mg, 6.0 mmol) were added. 60 mL of 1,4-dioxane was added, and the mixture was purged with nitrogen three times. The mixture was then heated to 110 °C and refluxed for 12 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with 50 mL of dichloromethane, and washed successively with saturated brine (3 × 50 mL). The organic phase was dried over anhydrous MgSO4, filtered, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography (eluent: dichloromethane / ethyl acetate = 2:1, v / v) to give a yellow solid, compound S2-Et, with a mass of 481 mg and a yield of 70%. MALDI-TOF-MS (m / z): Measured value 686.30, theoretical value C 37 H 39 N2O6P: 687.5.

[0027] 2. Synthesis of compound S2 Compound S2-Et (343.8 mg, 0.5 mmol) was dissolved in 30 mL of dichloromethane, and trimethylbromosilane (0.4 mL, 3.0 mmol) was slowly added dropwise while stirring at room temperature for 12 h. The solvent was removed by vacuum distillation, and 10 mL of methanol was added to the residue, with stirring continued for 3 h. 50 mL of deionized water was added, and a pale yellow-green solid precipitated. The solid was filtered, and the filter cake was washed three times with deionized water and dried under vacuum to give compound S2 with a mass of 246 mg, yielding 78%. 1 ¹H NMR (500MHz, DMSO) δ: 7.57–7.49 (m, 2H), 7.49–7.44 (m, 2H), 7.08–7.03 (m, 4H), 6.99–6.88 (m, 10H), 6.80–6.75 (m, 2H), 3.74 (s, 6H). MALDI-TOF-MS (m / z): Measured value 632.1, theoretical value C 32 H 28 BrN2O5P: 631.1.

[0028] Example 3: Synthesis of compound S3 The synthetic route for compound S3 is as follows: .

[0029] 1. Synthesis of compound S3-Et: In a 250 mL double-necked flask, S3-Br (633.0 mg, 1.0 mmol), diethyl phosphite (0.18 mL, 1.4 mmol), palladium acetate (2.3 mg, 0.01 mmol), 1,1'-bis(diphenylphosphine)ferrocene (110.8 mg, 0.2 mmol), and potassium acetate (588.8 mg, 6.0 mmol) were added. 60 mL of 1,4-dioxane was added, and the mixture was purged with nitrogen three times. The mixture was then heated to 110 °C and refluxed for 12 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with 50 mL of dichloromethane, and washed successively with saturated brine (3 × 50 mL). The organic phase was dried over anhydrous MgSO4, filtered, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography (eluent: dichloromethane / ethyl acetate = 2:1, v / v) to give a yellow solid, compound S3-Et, with a mass of 449 mg and a yield of 65%. MALDI-TOF-MS (m / z): Measured value 690.19, theoretical value C 40 H 39 N2O5PS: 690.23.

[0030] 2. Synthesis of compound S3 Compound S3-Et (345.1 mg, 0.5 mmol) was dissolved in 30 mL of dichloromethane, and trimethylbromosilane (0.4 mL, 3.0 mmol) was slowly added dropwise while stirring at room temperature for 12 h. The solvent was removed by vacuum distillation, and 10 mL of methanol was added to the residue, with stirring continued for 3 h. 50 mL of deionized water was added, and a green solid precipitated. The solid was filtered, and the filter cake was washed three times with deionized water and dried under vacuum to give compound S3 with a mass of 228 mg, yielding 72%. 1 ¹H NMR (400 MHz, DMSO) δ: 7.63–7.47 (m, 5H), 7.42 (d, J = 3.6 Hz, 1H), 7.15–7.10 (m, 1H), 7.09–7.02 (m, 6H), 7.01–6.89 (m, 8H), 6.83–6.75 (m, 2H), 3.74 (s, 6H). MALDI-TOF-MS (m / z): Measured value 634.02, theoretical value C 36 H 31 N2O5PS: 634.17.

[0031] Example 4: Synthesis of compound S4 The synthetic route for compound S4 is as follows: .

[0032] 1. Synthesis of compound S4-Et: In a 250 mL double-necked flask, S4-Br (607.1 mg, 1.0 mmol), diethyl phosphite (0.18 mL, 1.4 mmol), palladium acetate (2.3 mg, 0.01 mmol), 1,1'-bis(diphenylphosphine)ferrocene (110.8 mg, 0.2 mmol), and potassium acetate (588.8 mg, 6.0 mmol) were added. 60 mL of 1,4-dioxane was added, and the mixture was purged with nitrogen three times. The mixture was then heated to 110 °C and refluxed for 12 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with 50 mL of dichloromethane, and washed successively with saturated brine (3 × 50 mL). The organic phase was dried over anhydrous MgSO4, filtered, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography (eluent: dichloromethane / ethyl acetate = 2:1, v / v) to give a yellow solid, compound S4-Et, with a mass of 411 mg and a yield of 62%. MALDI-TOF-MS (m / z): Measured value 664.20, theoretical value C 38 H 37 N2O5PS: 664.22.

[0033] 2. Synthesis of compound S4 Compound S4-Et (332 mg, 0.5 mmol) was dissolved in 30 mL of dichloromethane, and trimethylbromosilane (0.4 mL, 3.0 mmol) was slowly added dropwise while stirring at room temperature for 12 h. The solvent was removed by vacuum distillation, and 10 mL of methanol was added to the residue, with stirring continued for 3 h. 50 mL of deionized water was added, and a green solid precipitated. The solid was filtered, and the filter cake was washed three times with deionized water and dried under vacuum to give compound S4 with a mass of 228 mg, yielding 75%. 1 ¹H NMR (400 MHz, DMSO) δ: 7.90–7.44 (m, 5H), 7.41 (d, J = 5.4 Hz, 1H), 7.23–6.70 (m, 15H), 3.74 (s, 6H). MALDI-TOF-MS (m / z): Measured value 608.04, theoretical value C 34 H 29 N2O5PS: 608.15.

[0034] Example 5: Fabrication and Performance Testing of Inverted Perovskite Solar Cells Based on Compound S1 1. Substrate pretreatment: The glass / ITO substrate was ultrasonically cleaned sequentially with detergent, deionized water, acetone and isopropanol for 15 minutes each, dried with nitrogen, and then treated with ozone for 15 minutes.

[0035] 2. Preparation of the hole transport layer: Compound S1 was dissolved in anhydrous ethanol at a concentration of 0.5 mg / mL and stirred until completely dissolved. The solution was then filtered through a 0.22 μm organic filter membrane. The pretreated substrate was placed on a spin coater, and the compound S1 solution was added dropwise. The mixture was spin-coated at 4000 rpm for 30 s and then annealed at 100 °C for 10 min to obtain the hole transport layer.

[0036] 3. Preparation of the perovskite layer: CsI, MAI, FAI, and PbI2 were dissolved in a DMF / DMSO mixed solvent (volume ratio 4:1) at a molar ratio of 0.05:0.1:0.85:1 to prepare a 1.6 mol / L perovskite precursor solution, which was stirred overnight. The precursor solution was dropped onto the hole transport layer and spin-coated at 4000 rpm for 30 s. At the 20th s of spin-coating, 100 μL of chlorobenzene was added as an anti-solvent. After spin-coating, the layer was immediately transferred to a 100℃ hot plate for annealing for 10 min to obtain the perovskite light-absorbing layer.

[0037] 4. Functional Layer and Electrode Fabrication: The substrate with the deposited perovskite layer was transferred to a vacuum evaporator, where 35 nm thick C layers were sequentially deposited. 60 The device is obtained by depositing an electron transport layer, a 10 nm thick 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) hole blocking layer, and finally a 110 nm thick silver electrode.

[0038] 5. Performance Testing: Under AM 1.5G standard solar intensity (100mW / cm²) 2 Under these conditions, a solar cell tester is used to test the device. JV Characteristics. Test results: Open circuit voltage (V) oc =1.15V, short-circuit current density (J) sc =24.72mA / cm 2 The fill factor (FF) is 84.54% and the photoelectric conversion efficiency (PCE) is 23.97%.

[0039] Example 6: Fabrication and Performance Testing of Inverted Perovskite Solar Cells Based on Compound S2 The preparation method is the same as in Example 5, except that the hole transport layer material is replaced with compound S2. Test results: Open-circuit voltage (V) oc =1.14V, short-circuit current density (J) sc =24.74 mA / cm 2 The fill factor (FF) is 82.51% and the photoelectric conversion efficiency (PCE) is 23.30%.

[0040] Example 7: Fabrication and Performance Testing of Inverted Perovskite Solar Cells Based on Compound S3 The preparation method is the same as in Example 5, except that the hole transport layer material is replaced with compound S3. Test results: Open-circuit voltage (V) oc =1.15V, short-circuit current density (J) sc =25.50mA / cm 2 The fill factor (FF) is 84.43% and the photoelectric conversion efficiency (PCE) is 24.71%.

[0041] Example 8: Fabrication and Performance Testing of Inverted Perovskite Solar Cells Based on Compound S4 The preparation method is the same as in Example 5, except that the hole transport layer material is replaced with compound S4. Test results: Open-circuit voltage (V) oc =1.15V, short-circuit current density (J) sc = 25.65 mA / cm 2 The fill factor (FF) is 84.06% and the photoelectric conversion efficiency (PCE) is 24.69%.

[0042] Comparative Example 1: Fabrication and Performance Testing of Inverted Perovskite Solar Cells Based on 4PACz The preparation method is the same as in Example 5, except that the hole transport layer material is replaced with the traditional SAMs material 4PACz. Test results: Open circuit voltage (V... oc =1.14V, short-circuit current density (J) sc =24.47 mA / cm 2 The fill factor (FF) is 83.02% and the photoelectric conversion efficiency (PCE) is 23.12%.

[0043] The device performance comparison results show that the self-assembled monolayer hole transport materials based on the triphenylamine framework prepared in this invention can significantly improve the photoelectric conversion efficiency of inverted perovskite solar cells. Among them, the efficiency of the S3 and S4-based devices reached 24.71% and 24.69%, respectively, which are significantly improved compared with the traditional 4PACz-based devices, proving the superiority of the technical solution of this invention.

[0044] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A self-assembled monolayer hole transport material based on a triphenylamine framework, characterized in that, The structural formula of the self-assembled monolayer hole transport material based on the triphenylamine framework is as follows: , where X1-X 10 The groups are independently derived from hydrogen, halogen, cyano, nitro, amino, substituted or unsubstituted C1-C6 monoalkylamino, substituted or unsubstituted (di(C1-C6 alkyl))amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, or substituted or unsubstituted C1-C6 alkylthio. R1-R5 are independently derived from hydrogen, halogen, cyano, nitro, amino, substituted or unsubstituted C1-C6 monoalkylamino, substituted or unsubstituted (di(C1-C6 alkyl))amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C1-C6 alkylthio, substituted or unsubstituted C6-C 10 aryl, substituted or unsubstituted C2-C 10 Heteroaryl groups; or R1-R5 independently form substituted or unsubstituted C6-C groups with carbon atoms attached to and adjacent to the benzene ring. 10 Aromatic rings, or carbon atoms attached to or adjacent to the benzene ring, form substituted or unsubstituted C2-C bonds. 10 Mixed fragrance ring.

2. The self-assembled monolayer hole transport material based on a triphenylamine framework as described in claim 1, characterized in that, The self-assembled monolayer hole transport material based on the triphenylamine framework is selected from any of the following structures: Among them, compound S1 is tris(4-methoxyphenyl)aniline phosphonic acid; compound S2 is (4'-bromo-4,4''-dimethoxytriphenylamino)phosphonic acid; compound S3 is (4-(benzo[b]thiophen-2-yl)-4',4''-dimethoxytriphenylamino)phosphonic acid; and compound S4 is (4-(thiophen-2-yl)-4',4''-dimethoxytriphenylamino)phosphonic acid.

3. A method for preparing a self-assembled monolayer hole transport material based on a triphenylamine framework as described in claim 1, characterized in that, Includes the following steps: a. Coupling reaction: The triphenylamine compound is coupled with diethyl phosphite in the presence of a palladium catalyst, ligand and base in a first organic solvent to generate a phosphonate intermediate compound; b. Hydrolysis reaction: The phosphonate intermediate compound and trimethylbromosilane are hydrolyzed in a second organic solvent. After hydrolysis, methanol is added and stirred, then deionized water is added. After the product is precipitated, it is washed with water to obtain a self-assembled monolayer hole transport material based on a triphenylamine framework.

4. The method for preparing a self-assembled monolayer hole transport material based on a triphenylamine framework as described in claim 3, characterized in that: In step a, the palladium catalyst is palladium acetate, the ligand is 1,1'-bis(diphenylphosphine)ferrocene, and the base is potassium acetate; the molar ratio of the bromotriphenylamine compound to diethyl phosphite is 1:(1.05-1.50), and the molar equivalents of palladium acetate, 1,1'-bis(diphenylphosphine)ferrocene, and potassium acetate relative to the bromotriphenylamine compound are 0.01 eq, 0.2 eq, and 6.0 eq, respectively; the first organic solvent is 1,4-dioxane; the reaction temperature of the carbon-phosphine bond coupling reaction is 100-110℃, the reaction time is 8-12 h, and the reaction is carried out under inert gas protection.

5. The method for preparing a self-assembled monolayer hole transport material based on a triphenylamine framework as described in claim 3, characterized in that: In step b, the molar ratio of the phosphonate intermediate compound to trimethylbromosilane is 1:(5-10); the second organic solvent is dichloromethane; the hydrolysis reaction is carried out at a temperature of 25-35°C for 12-24 hours.

6. The application of a self-assembled monolayer hole transport material based on a triphenylamine framework as described in any one of claims 1 or 2 as a hole transport layer in perovskite solar cells.

7. An inverted perovskite solar cell, characterized in that, It includes a substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, a hole blocking layer, and a counter electrode, which are stacked sequentially; the hole transport layer is the self-assembled monolayer hole transport material based on a triphenylamine framework as described in claim 1 or 2.

8. The inverted perovskite solar cell as described in claim 7, characterized in that: The substrate is a glass or ITO substrate; the perovskite light-absorbing layer is composed of Cs. 0.05 MA 0.1 FA 0.85 PbI3, with a thickness of 300-500 nm, wherein MA + It is a methylammonium cation, FA + It is a formamidinium cation; the electron transport layer is [6,6]-phenyl-C 61 -Methyl butyrate or C 60 The thickness is 30-40 nm; the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline with a thickness of 10 nm; the counter electrode is a silver electrode with a thickness of 110 nm.

9. A method for fabricating an inverted perovskite solar cell as described in any one of claims 7 or 8, characterized in that, Includes the following steps: (1) Hole transport layer preparation: The self-assembled monolayer hole transport material based on the triphenylamine framework was dissolved in ethanol at a concentration of 0.5 mg / mL to obtain a precursor solution; A clean, ozone-treated substrate was placed on a spin coater, a precursor solution was added dropwise for spin coating, and a hole transport layer was obtained after annealing. (2) Preparation of perovskite light-absorbing layer: The perovskite precursor solution is deposited onto the hole transport layer, spin-coated, and then annealed to obtain the perovskite light-absorbing layer; the perovskite precursor solution is Cs with a concentration of 1.5-2 mol / L. 0.05 MA 0.1 FA 0.85 PbI3 solution; (3) Functional layer preparation: An electron transport layer and a hole blocking layer are prepared sequentially on the perovskite light absorption layer; (4) Electrode preparation: Silver electrodes are deposited on the hole blocking layer to obtain the inverted perovskite solar cell.

Images