Self-assembled monomolecular layer material based on a conjugated linker group, preparation method therefor, and solar cell

Abstract

The present invention relates to the technical field of photoelectric devices, in particular to a self-assembled monomolecular layer material based on a conjugated linker group, a preparation method therefor, and a solar cell. The chemical structural general formula of said self-assembled monomolecular layer material is shown as (1), wherein an electron donor is one of electron-rich groups and derivatives thereof, and L is a conjugated linker group. The introduction of the conjugated linker group into the self-assembled monomolecular layer material to replace a non-conjugated alkyl linker group can effectively achieve electron delocalization, thereby enhancing the intrinsic stability and hole extraction and transport capability of molecules in monomolecular self-assembled layers. In addition, the rigid structure thereof remarkably improves the degree of order and the density of molecular arrangement of monomolecular self-assembled layers. Moreover, the self-assembled monomolecular layer material can form dense monomolecular self-assembled layers on the surfaces of conductive substrates, thereby improving interface contact and passivating interface defects; and said material can form dipoles on the surfaces of the conductive substrates, thereby improving the surface work function and promoting hole transport.

Description

A self-assembled monolayer material based on conjugated linking groups, a preparation method thereof, and a solar cell Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a self-assembled monolayer material based on conjugated linking groups, a preparation method thereof, and a solar cell. Background Art

[0002] Perovskite solar cells are a new type of photovoltaic device that uses semiconductor materials with a perovskite structure as a light absorption layer to achieve efficient photoelectric conversion. A type of inverse perovskite solar cell is a perovskite solar cell with an inverse structure, that is, a hole transport layer is inserted between the substrate electrode and the perovskite layer, and an electron transport layer is inserted between the perovskite layer and the transparent electrode. This structure can effectively improve the selective extraction and transport of carriers, thereby improving the efficiency and stability of the device. At present, inverse perovskite solar cells have achieved the world's highest efficiency of 25.7%, exceeding the efficiency of polycrystalline silicon solar cells; however, the hole transport layers commonly used in inverse perovskite solar cells, such as poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), nickel oxide (NiO x ), PEDOT:PSS, still has defects such as low wettability, poor interface contact or difficulty in preparing large-area devices. These problems limit its further performance improvement and commercial application.

[0003] In order to solve these problems, an effective strategy is to introduce a self-assembled monolayer between the perovskite layer and the electrode to improve the interface quality and charge extraction; the self-assembled monolayer is an effective single-molecule array formed spontaneously by organic molecules on the solid surface, and the interface properties can be precisely controlled by adjusting the molecular structure and functional groups. Currently, the widely used self-assembled molecular layer materials such as [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl] acid phosphine are soluble in common polar solvents such as methanol, ethanol, isopropanol, N,N ， -It has a certain solubility in dimethylformamide and can form a single-molecule self-assembled layer by simple methods such as immersion or spin coating. However, the single-molecule self-assembled layer materials containing alkyl chain connecting groups have defects such as poor stability, disordered orientation, and low arrangement density. Although great progress has been made, problems such as improving the stability of inverse perovskite solar cell devices and further improving the photoelectric conversion efficiency still need to be solved.

[0004] Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a self-assembled monolayer material based on conjugated linking groups, a preparation method thereof, and a solar cell, aiming to solve the problems of poor stability, disordered orientation, and low arrangement density of existing monomolecular self-assembled layer materials containing alkyl chain linking groups.

[0006] The technical solutions of the present invention are as follows:

[0007] A self-assembled monolayer material based on a conjugated linking group, wherein the general chemical structure of the self-assembled monolayer material based on a conjugated linking group is:

[0008] The electron donor is one of the electron-rich groups and their derivatives; and L is a conjugated connecting group.

[0009] A method for preparing a self-assembled monolayer material based on a conjugated linking group comprises the steps of:

[0010] An electron-rich compound containing an imine structure undergoes an Ullmann reaction with a conjugated compound containing two halogen groups to obtain a first intermediate;

[0011] The first intermediate is subjected to a palladium-catalyzed carbon-phosphine coupling reaction to obtain a second intermediate containing a phosphonate;

[0012] The alkoxy group in the second intermediate containing phosphonate is converted into a hydroxyl group by using trimethylsilyl bromide to obtain the self-assembled monolayer material based on the conjugated linking group.

[0013] A solar cell, characterized in that the solar cell comprises a self-assembled monolayer or a hole transport layer, and the self-assembled monolayer or the hole transport layer comprises the self-assembled monolayer material based on conjugated linking groups.

[0014] Beneficial effects: The present invention provides a self-assembled monolayer material based on a conjugated linking group, a preparation method thereof, and a solar cell. The general chemical structure formula of the self-assembled monolayer material based on a conjugated linking group is: The electron donor is one of an electron-rich group and its derivatives; L is a conjugated linking group. Introducing a conjugated linking group in place of a non-conjugated alkyl linking group in a self-assembled monolayer material can effectively achieve electron delocalization, enhancing the intrinsic stability of the monolayer molecules and the hole extraction and transport capabilities. Furthermore, due to its rigid structure, the order and density of the monolayer molecular arrangement are significantly improved. Furthermore, the self-assembled monolayer material based on the conjugated linking group can form a dense monolayer on the surface of a conductive substrate, improving interfacial contact and passivating interfacial defects. It can also form a dipole on the surface of the conductive substrate, increasing the surface work function and promoting hole transport. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a hydrogen nuclear magnetic resonance spectrum of MeCz-PhBr in Example 1;

[0016] FIG2 is a hydrogen nuclear magnetic resonance spectrum of MeCz-PhP in Example 1;

[0017] FIG3 is a proton nuclear magnetic resonance spectrum of Me-PhpPACz in Example 1;

[0018] FIG4 is a schematic diagram of the structure of an inverted planar heterojunction perovskite solar cell;

[0019] FIG5 is a JV curve of a perovskite solar cell based on a transport layer Me-PhpPACz;

[0020] FIG6 is a hydrogen nuclear magnetic resonance spectrum of Cz-PhBr in Example 2;

[0021] FIG7 is a hydrogen nuclear magnetic resonance spectrum of Cz-PhP in Example 2;

[0022] FIG8 is a proton nuclear magnetic resonance spectrum of PhpPACz in Example 2;

[0023] FIG9 is a JV curve diagram of a perovskite solar cell based on a transport layer PhpPACz according to Example 2;

[0024] FIG10 is a hydrogen nuclear magnetic resonance spectrum of MeOCz-PhBr in Example 3;

[0025] FIG11 is a hydrogen nuclear magnetic resonance spectrum of MeOCz-PhP in Example 3;

[0026] FIG12 is a hydrogen nuclear magnetic resonance spectrum of MeO-PhpPACz in Example 3;

[0027] FIG13 is a JV curve of a perovskite solar cell based on a transport layer MeO-PhpPACz;

[0028] FIG14 is a hydrogen nuclear magnetic resonance spectrum of NapCz-PhBr in Example 4;

[0029] FIG15 is a hydrogen nuclear magnetic resonance spectrum of NapCz-PhP in Example 4;

[0030] FIG16 is a hydrogen nuclear magnetic resonance spectrum of Nap-PhpPACz in Example 4;

[0031] FIG17 is a JV curve of a perovskite solar cell based on a transport layer Nap-PhpPACz;

[0032] FIG18 is a hydrogen NMR spectrum of MMT-PhBr in Example 5;

[0033] FIG19 is a hydrogen nuclear magnetic resonance spectrum of MMT-PhP in Example 5;

[0034] Figure 20 is a hydrogen nuclear magnetic resonance spectrum of MMT-PhpPACz in Example 5;

[0035] FIG21 is a JV curve of a perovskite solar cell based on a transport layer MMT-PhpPACz;

[0036] FIG22 is a proton nuclear magnetic resonance spectrum of MONCz-PhBr in Example 6;

[0037] FIG23 is a proton nuclear magnetic resonance spectrum of MONCz-PhP in Example 6;

[0038] FIG24 is a hydrogen nuclear magnetic resonance spectrum of MON-PhpPACz in Example 6;

[0039] FIG25 is a JV curve of a perovskite solar cell based on a transport layer MON-PhpPACz;

[0040] FIG26 is a structural diagram of a perovskite device containing a monolayer in Comparative Example 1;

[0041] FIG27 is an IV curve diagram of the perovskite solar cell of Comparative Example 1;

[0042] Figure 28 is a stability test diagram of the perovskite solar cell device of Comparative Example 1. DETAILED DESCRIPTION

[0043] The present invention provides a self-assembled monolayer material based on conjugated linking groups, a preparation method thereof, and a solar cell. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0044] Self-assembled molecular layers can act as intermediate connectors, enabling tight bonding between layers, regulating interfacial energy levels, suppressing interfacial defects, and promoting charge extraction and transport. Currently widely used self-assembled monolayer materials typically have the following structure: 1. Head groups, such as electron donors like carbazole and phenothiazine, which can passivate interfacial defects, regulate energy levels, and achieve efficient charge extraction and transport; 2. Linking groups, such as alkyl chains of varying lengths, which provide the material with self-assembly flexibility; and 3. Anchoring groups, such as phosphonic acid, which can form effective covalent bonds with commonly used transparent conductive substrates through chemical reactions and have been shown to be the most tightly bound anchoring groups of their kind to specific metal oxides.

[0045] However, existing single-molecule self-assembled layer materials containing alkyl chain connecting groups have defects such as poor stability, disordered orientation, and low arrangement density. Although great progress has been made, problems such as improving the stability of solar cell devices and further improving the photoelectric conversion efficiency still need to be solved.

[0046] Based on this, as shown in FIG1 , the present invention provides a self-assembled monolayer material based on a conjugated linking group, and the general chemical structure of the self-assembled monolayer material based on a conjugated linking group is:

[0047] The electron donor is one of the electron-rich groups and their derivatives; and L is a conjugated connecting group.

[0048] In this embodiment, a conjugated linking group is introduced into the self-assembled monolayer material to replace the non-conjugated alkyl linking group, and a series of self-assembled monolayer materials based on conjugated linking groups are constructed, aiming to enhance its intrinsic stability, improve self-assembly performance, and improve hole extraction and transmission capabilities. The comparison of cyclic voltammetry and nuclear magnetic resonance detection before and after illumination shows that compared with the monomolecular self-assembled layer material of the non-conjugated linking group, the self-assembled monolayer material based on the conjugated linking group has higher electrochemical and photostability, is dissolved in an alcohol solvent, and a monomolecular self-assembled layer is formed on the surface of a conductive substrate by spin coating. It is confirmed by XPS surface scanning that a tighter monomolecular self-assembled layer is formed. At the same time, based on the dipole moment and molecular orientation of the material, the surface work function of the conductive substrate is significantly improved.

[0049] Specifically, the self-assembled monolayer material based on conjugated linking groups provided in this embodiment has the following beneficial effects: (1) the self-assembled monolayer material based on conjugated linking groups has obvious electron delocalization and high intrinsic stability; (2) the self-assembled monolayer material based on conjugated linking groups can form a denser self-assembled layer on a conductive substrate; (3) the surface work function of the conductive substrate can be effectively regulated; and (4) the monolayer self-assembled layer can have stronger hole extraction and transmission capabilities.

[0050] In some embodiments, the electron donor in the chemical structural formula is an electron-rich group such as carbazole, phenothiazine, phenoxazine, diphenylamine, and its derivatives; L in the chemical structural formula is a conjugated linking group such as benzene, biphenyl, anthracene, phenanthrene, pyrene, pyridine, pyrimidine, furan, thiophene, quinoline, etc. The self-assembled monolayer material based on the conjugated linking group forms a self-assembled monolayer on a transparent conductive substrate during the spin coating process through the anchoring effect of the phosphate group on the metal oxide, which can adjust the surface work function of the conductive glass and improve the interface energy level matching; at the same time, the conjugated linking group in this type of material can enhance the interaction between molecules within the layer to form a denser monomolecular self-assembled layer; and the conjugated linking group has strong conductivity and can promote charge transfer. In addition, since the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are localized in the electron donor and the conjugated linking group L, respectively, this type of material has excellent optical and electrical stability.

[0051] In some embodiments, the electron donor is selected from One of the following;

[0052] Among them, R1-R 14 are independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 Alkenyl, C2-C 60 Alkynyl, C1-C 60 Alkoxy, C1-C 60 Alkylthio, C3-C 60 Cycloalkyl, C1-C 10 Heterocycloalkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocycloalkenyl, C6-C 60 Aryl, C1-C 60 One of a heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

[0053] In some embodiments, the L is selected from One of them.

[0054] In addition, the present invention also provides a method for preparing a self-assembled monolayer material based on a conjugated linking group, comprising the steps of:

[0055] Step S10: performing an Ullmann reaction on an electron-rich compound containing an imine structure and a conjugated compound containing two halogen groups to obtain a first intermediate;

[0056] Step S20: subjecting the first intermediate to a palladium-catalyzed carbon-phosphine coupling reaction to obtain a second intermediate containing a phosphonate;

[0057] Step S30: using trimethylsilyl bromide to convert the alkoxy group in the second intermediate containing phosphonate into a hydroxyl group, thereby obtaining the self-assembled monolayer material based on the conjugated linking group.

[0058] In this embodiment, an electron donor containing an imine (-NH-) structure is first subjected to an Ullmann reaction with a conjugated linker X1-L-X2 containing two halogen groups -X1 and -X2 (-I, -Br, -Cl, -F) to obtain a first intermediate; then, the first intermediate is subjected to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a second intermediate containing a phosphonate; finally, the alkoxy group (-OR) in the phosphonate in the second intermediate is converted into a hydroxyl group (-OH) by trimethylsilyl bromide (TMSBr) to obtain a self-assembled monolayer material based on a conjugated linker group.

[0059] Specifically, the synthetic route of the preparation method of the self-assembled monolayer material based on conjugated linking groups is as follows:

[0060] In some embodiments, the step of subjecting the electron donor containing an imine structure to an Ullmann reaction with a conjugated linker containing two halogen groups to obtain a first intermediate comprises: mixing the electron donor, the conjugated linker, a catalyst, a ligand, a base, and a solvent in an inert gas atmosphere to obtain a reaction system; heating the reaction system to a first reflux temperature and keeping it warm for a first predetermined time to obtain the first intermediate.

[0061] In some embodiments, the catalyst is at least one of copper powder, cuprous oxide, cuprous iodide, cuprous bromide, and cuprous chloride; the ligand is at least one of L-proline, 18-crown ether-6, 1,2-cyclohexanediamine, 1,10-phenanthroline, and oxalyl diamide ligands; the base is at least one of potassium carbonate, potassium hydroxide, potassium phosphate, and potassium tert-butoxide; and the solvent is an organic solvent.

[0062] For example, under an inert gas atmosphere, an electron donor (1 equivalent) and a conjugated linker (2 equivalents) are mixed in a reaction system comprising cuprous iodide (0.1 equivalent) as a catalyst, 1,2-cyclohexanediamine (0.2 equivalent) as a ligand, potassium phosphate (3 equivalents) as a base, and toluene as a solvent, and heated to a first reflux temperature and maintained for a first predetermined time to obtain the first intermediate; the first reflux temperature is 105-115° C., and the first predetermined time is 12-48 hours. Preferably, the first reflux temperature is 110° C.

[0063] In some embodiments, the step of subjecting the first intermediate to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a second intermediate containing a phosphonate comprises: mixing the first intermediate with diethyl phosphite in a reaction system comprising palladium acetate as a catalyst, 1,1'-bis(diphenylphosphino)ferrocene as a ligand, triethylamine as a base, potassium acetate as an additive, and tetrahydrofuran as a solvent in an inert gas atmosphere to obtain a mixed solution; heating the mixed solution to a second reflux temperature and keeping it warm for a second predetermined time to obtain the second intermediate containing a phosphonate.

[0064] For example, in the middle of an inert gas range, the first intermediate (1 equivalent) and diethyl phosphite (1 equivalent) are mixed in a reaction system comprising palladium acetate (0.025 equivalent) as a catalyst, 1,1'-bis(diphenylphosphino)ferrocene (0.05 equivalent) as a ligand, triethylamine (1.2 equivalents) as a base, potassium acetate (0.1 equivalents) as an additive, and tetrahydrofuran as a solvent, and heated to a second reflux temperature and maintained for a second predetermined time to obtain a second intermediate containing a phosphonate; the second reflux temperature is 64-68°C, and the second predetermined time is 12-24 hours; preferably, the second reflux temperature is 66°C.

[0065] In some embodiments, the step of converting the alkoxy group in the second intermediate containing the phosphonate into a hydroxyl group using trimethylsilyl bromide to obtain the self-assembled monolayer material based on the conjugated linking group comprises: mixing trimethylsilyl bromide with the second intermediate containing the phosphonate in anhydrous dichloromethane or 1,4-dioxane in an inert gas atmosphere to obtain a mixed solution; and reacting the mixed solution at room temperature for a third predetermined time to obtain the self-assembled monolayer material based on the conjugated linking group.

[0066] For example, trimethylsilyl bromide (4 equivalents) is mixed with the second intermediate containing the phosphonate in anhydrous dichloromethane or 1,4-dioxane in an inert gas atmosphere, and then reacted at room temperature for 12-24 hours, followed by quenching with methanol or water to convert the alkoxy group contained in the phosphonate in the second intermediate into a hydroxyl group to obtain the self-assembled monolayer material based on the conjugated linking group.

[0067] In addition, the present invention also provides a solar cell, which includes a self-assembled monolayer or a hole transport layer, and the self-assembled monolayer or the hole transport layer includes the self-assembled monolayer material based on conjugated linking groups.

[0068] In this embodiment, the self-assembled monolayer material based on conjugated linking groups is used in solar cells. This type of material can effectively improve the quality of the monomolecule self-assembled layer, enhance stability and hole extraction ability, improve interface contact and energy level arrangement, and realize solar cells with high efficiency and good stability.

[0069] In some embodiments, the solar cell comprises one or more of a perovskite solar cell or an organic solar cell; the perovskite solar cell is a lead-based ABX3 compound. The electron donor in the self-assembled monolayer material based on the conjugated linker can directly contact the perovskite underlying interface. By introducing passivating groups through rational molecular modification, interfacial defects can be passivated, facilitating the formation of high-quality perovskite films.

[0070] Specifically, the self-assembled monolayer material based on the conjugated linking group is applied to the surface of conductive glass, perovskite, tin oxide, titanium oxide, aluminum oxide or nickel oxide, and a solar cell based on the self-assembled monolayer material is manufactured.

[0071] In some embodiments, the conductive glass includes but is not limited to one or more metal oxides such as FTO, ITO, and AZO.

[0072] In some embodiments, the nickel oxide is nickel monoxide or nickel trioxide.

[0073] In a preferred embodiment, the perovskite solar cell is an inverted perovskite solar cell; the application of a monomolecular self-assembled layer material containing a conjugated linking group to an inverted perovskite solar cell device improves the hole extraction capacity, improves the stability of the reactive perovskite solar cell, and realizes a high-efficiency device with a high open-circuit voltage and a high fill factor. At the same time, this type of material has the advantages of a short preparation process and low consumption, which is conducive to further realizing the large-scale, low-cost preparation and commercialization of inverted perovskite solar cell devices. Monomolecular self-assembled layer materials based on conjugated groups have high intrinsic stability and hole extraction capacity. Inverted perovskite solar cells prepared based on this type of material have the advantages of good repeatability, high photoelectric conversion efficiency, and good device performance stability.

[0074] Specifically, the self-assembled monolayer material based on the conjugated linker can effectively adjust the surface work function of conductive glass, improve interfacial contact, promote charge conduction, and realize efficient and stable inverse perovskite solar cells. Due to the strong anchoring effect of the phosphate group on common metal oxides, this type of material can also be widely used in optoelectronic devices such as perovskite light-emitting diodes, organic solar cells, organic light-emitting diodes, and field-effect transistors.

[0075] The present invention will be described in detail with reference to the following examples. It should also be understood that the following examples are only intended to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above disclosure of the present invention fall within the scope of protection of the present invention.

[0076] Example 1

[0077] The synthetic compound Me-PhpPACz is synthesized by the following synthesis route:

[0078] 1. Synthesis of MeCz-PhBr

[0079] 3,6-Dimethylcarbazole (1.95 g, 10 mmol), 1-bromo-4-iodobenzene (5.66 g, 20 mmol), cuprous iodide (0.190 g, 1 mmol), 1,2-cyclohexanediamine (0.228 g, 2 mmol) and potassium phosphate (6.37 g, 30 mmol) were added to a dried 250 mL two-necked flask. Under an argon atmosphere, 50 mL of toluene was added and heated under reflux for 12 hours. After the reaction mixture was cooled to room temperature, it was extracted with dichloromethane and saturated brine, and the organic phases were combined and dried over anhydrous sodium sulfate. The dried solution was distilled to remove the solvent to obtain a crude product, which was further purified by column chromatography using silica gel as the stationary phase and dichloromethane and petroleum ether as eluents to obtain 3.32 g of a white solid product (95%), which is MeCz-PhBr. The H NMR spectrum of MeCz-PhBr is shown in Figure 1. The H NMR spectrum data are: 1 H NMR (400 MHz, CDCl3) δ7.93–7.88 (m, 2H), 7.74–7.68 (m, 2H), 7.47–7.41 (m, 2H), 7.28 (d, J = 8.3 Hz, 2H), 7.22 (dd, J = 8.5, 1.7 Hz, 2H), 2.55 (s, 6H), indicating that MeCz-PhBr was successfully synthesized.

[0080] 2. Synthesis of MeCz-PhP

[0081] Palladium acetate (16.8 mg, 0.075 mmol), 1,1'-bis(diphenylphosphino)ferrocene (83.2 mg, 0.15 mmol), potassium acetate (29.4 mg, 0.3 mmol), and MeCz-PhBr (1.05 g, 3 mmol) were added to a dry 100 mL two-necked flask. Triethylamine (364 mg, 3.6 mmol) and 30 mL of tetrahydrofuran bubbling with argon were then added, and the reaction mixture was stirred at the boil for 15 minutes. Diethyl phosphite (414 mg, 3 mmol) was then added, and stirring continued at the boil for 12 hours. After cooling to room temperature, the reaction mixture was filtered through Celite and rinsed with tetrahydrofuran. The filtrate was freed from the solvent using a rotary evaporator, and the crude product was purified by silica gel column chromatography to yield MeCz-PhP as a white solid (1.15 g, 94%). The H NMR spectrum of MeCz-PhP is shown in Figure 2. The H NMR spectrum data are: 1 H NMR (400 MHz, CDCl3) δ8.07–7.98 (m, 2H), 7.89 (d, J = 1.8 Hz, 2H), 7.74–7.65 (m, 2H), 7.37 (d, J = 8.4 Hz, 2H), 7.22 (dd, J = 8.5, 1.8 Hz, 2H), 4.35–4.09 (m, 4H), 2.54 (s, 6H), 1.40 (t, J = 7.1 Hz, 6H), indicating that MeCz-PhP was successfully synthesized.

[0082] 3. Synthesis of Me-PhpPACz

[0083] Under argon atmosphere, 20 mL of dichloromethane was added to a 50 mL two-necked flask containing MeCz-PhP (0.407 g, 1 mmol). Under stirring, trimethylsilyl bromide (0.612 g, 4 mmol) was added dropwise, and the reaction mixture was stirred for 12 hours. The reaction mixture was transferred to a 100 mL round-bottom flask, the solvent was removed using a rotary evaporator, and 20 mL of methanol was added and stirred for 4 hours. After the reaction was completed, the solvent was removed again using a rotary evaporator to obtain a crude product, which was then recrystallized using a methanol / dichloromethane / ether system to obtain a white solid product (0.350 g, 99.5%). The H NMR spectrum of Me-PhpPACz is shown in Figure 3, and the H NMR spectrum data are: 1 H NMR (400 MHz, DMSO-d6) δ8.05–7.90 (m, 4H), 7.70 (dd, J = 8.4, 2.9 Hz, 2H), 7.35 (d, J = 8.4 Hz, 2H), 7.23 (dd, J = 8.5, 1.3 Hz, 2H), 2.48 (s, 6H), indicating that Me-PhpPACz was successfully synthesized.

[0084] 4. Use the prepared Me-PhpPACz in solar cells

[0085] The Me-PhpPACz prepared in step 3 can be used in perovskite solar cells and organic solar cells. Specifically, taking the inverted planar heterojunction perovskite solar cell as an example, the structural schematic diagram of the inverted planar heterojunction perovskite solar cell involved in this embodiment is shown in Figure 4, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of Me-PhpPACz or a hole transport layer; (3) a perovskite light absorbing layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode. The preparation of the inverted planar heterojunction perovskite solar cell specifically includes the following steps:

[0086] 1) Cleaning the transparent conductive substrate ITO

[0087] The etched transparent conductive substrate ITO was ultrasonically placed in a cleaning agent, deionized water, anhydrous ethanol, acetone, and isopropanol for 15 minutes in sequence. After being taken out, it was blown dry with clean air, placed in an oven, dried at 120°C for 8 hours, and treated with UV / ozone for 30 minutes.

[0088] 2) Preparation of monomolecular self-assembled layers (SAM)

[0089] A Me-PhpPACz solution was prepared; the solution was spin-coated on a transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; and the obtained film was annealed in nitrogen at 100° C. for 10 minutes.

[0090] 3) Preparation of perovskite light-absorbing layer

[0091] Any ABX3 has a perovskite structure, where A is any organic cation, such as formamidine (FA) or methylamine (MA); B is any metal cation, such as lead or tin; and X is any halogen anion, such as chloride, bromide, or iodine. ABX3 is prepared by dissolving it in a solvent such as DMF, DMSO, or NMP. It is spin-coated onto ITO in two steps: 1000 rpm for 10 seconds and 6000 rpm for 20 seconds. With 5 seconds remaining, chlorobenzene is dripped onto the substrate, and the film is annealed at 100°C for 0.5 hours.

[0092] 4) Preparation of electron transport layer

[0093] In 1×10 -6 Pa vacuum, C60 was deposited on the perovskite surface.

[0094] 5) Preparation of copper or silver electrodes

[0095] In 1×10 -6 Pa vacuum degree, Copper or silver electrodes were prepared by rate evaporation deposition, and the electrode thickness was controlled to be ∼100 nm.

[0096] 6) Testing

[0097] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0098] The test results are shown in Figure 5. The parameters for the best photoelectric conversion efficiency are: open circuit voltage 1.19V, short circuit current density 25.4mA / cm 2 , fill factor 87.1%, conversion efficiency 26.2%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 99% of its initial efficiency.

[0099] Example 2

[0100] The synthetic compound PhpPACz is synthesized by the following synthesis route:

[0101] 1. Synthesis of Cz-PhBr

[0102] The raw material 3,6-dimethylcarbazole used in the synthesis of MeCz-PhBr in Example 1 was replaced with an equal amount of carbazole, and Cz-PhBr (2.67 g, 82.9%) was obtained according to the synthesis method of MeCz-PhBr. The H NMR spectrum of Cz-PhBr is shown in Figure 6. The H NMR spectrum data are: 1 H NMR(400MHz, CDCl3)δ / ppm 8.16(d,J=7.7Hz,2H),7.78–7.69(m,2H),7.49–7.41(m,4H),7.39(dt,J=8.1,1.2Hz,2H),7.32(ddd,J=8.0,6.8,1.4Hz,2H).

[0103] 2. Synthesis of Cz-PhP

[0104] The MeCz-PhBr used in the synthesis of MeCz-PhP in Example 1 was replaced with an equal amount of Cz-PhBr, and Cz-PhP (0.962 g, 84.5%) was obtained according to the synthesis method of MeCz-PhP. The H NMR spectrum of Cz-PhP is shown in FIG7 . The H NMR spectrum data are: 1HNMR(400MHz,CDCl3)δ / ppm 8.15(dt,J=7.8,1.0Hz,2H),8.10–8.01(m,2H),7.76–7.68(m,2H),7.48(dt,J=8.2,1.0Hz,2H),7.43(d dd,J=8.2,6.9,1.2Hz,2H),7.32(ddd,J=7.9,6.9,1.2Hz,2H),4.33–4.13(m,4H),1.41(t,J=7.1Hz,6H).

[0105] 3. Synthesis of PhpPACz

[0106] The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with an equal amount of Cz-PhP, and PhpPACz (0.310 g, 95.8%) was obtained according to the synthesis method of Me-PhpPACz. The H NMR spectrum of PhpPACz is shown in FIG8 . The H NMR spectrum data are: 1 H NMR(400MHz,DMSO-d6)δ / ppm 8.26(d,J=7.7Hz,2H),7.97(dd,J=12.6,8.3Hz,2H),7.75(dd,J=8.3,2.9Hz,2H),7.48–7.41(m,4H),7.31(ddd,J=7.9,5.1,3.0Hz,2H).

[0107] 4. Preparation of solar cell devices

[0108] The solar cells involved in this embodiment include perovskite solar cells and organic solar cells, specifically taking an inverted planar heterojunction perovskite solar cell as an example. FIG4 is a schematic structural diagram of the inverted planar heterojunction perovskite solar cell involved in this embodiment, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of PhpPACz or a hole transport layer; (3) a perovskite light absorption layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode.

[0109] 1) Cleaning the transparent conductive substrate ITO: the same as in Example 1;

[0110] 2) Preparation of monomolecular self-assembled layers (SAM)

[0111] A PhpPACz solution was prepared; the solution was spin-coated on a transparent conductive ITO substrate at a speed of 4000 rpm for 40 seconds; the resulting film was annealed in nitrogen at 100°C for 10 minutes;

[0112] 3) Preparation of perovskite light absorbing layer: same as in Example 1;

[0113] 4) Preparation of electron transport layer: same as in Example 1;

[0114] 5) Preparation of copper or silver electrodes: same as in Example 1;

[0115] 6) Testing

[0116] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0117] The test results are shown in Figure 9. The optimal photoelectric conversion efficiency parameters achieved were: open-circuit voltage of 1.17V, short-circuit current density of 24.6mA / cm², fill factor of 84.6%, and conversion efficiency of 24.3%. Even after 3000 hours of storage in atmospheric air, the device maintained over 95% of its initial efficiency.

[0118] Example 3

[0119] The synthetic compound MeO-PhpPACz is synthesized by the following synthesis route:

[0120] 1. Synthesis of MeOCz-PhBr

[0121] The raw material 3,6-dimethylcarbazole used in the synthesis of MeCz-PhBr in Example 1 was replaced with an equal amount of 3,6-dimethoxycarbazole, and MeOCz-PhBr (3.55 g, 92.9%) was obtained according to the synthesis method of MeCz-PhBr. The H NMR spectrum of MeOCz-PhBr is shown in Figure 10. The H NMR spectrum data are: 1 H NMR(400MHz, CDCl3)δ / ppm 7.75–7.65(m,2H),7.55(d,J=2.5Hz,2H),7.45–7.38(m,2H),7.30(d,J=8.9Hz,2H),7.04(dd,J=8.9,2.5Hz,2H),3.95 (s,6H).

[0122] 2. Synthesis of MeOCz-PhP

[0123] The MeCz-PhBr used in the synthesis of MeCz-PhP in Example 1 was replaced with an equal amount of Cz-PhBr, and Cz-PhP (1.04 g, 79.1%) was obtained according to the synthesis method of MeCz-PhP. The H NMR spectrum of Cz-PhP is shown in FIG11 . The H NMR spectrum data are: 1 H NMR(400MHz, CDCl3)δ / ppm 8.02(dd,J=12.9,8.3Hz,2H),7.68(dd,J=8.3,3.5Hz,2H),7.54(d,J=2.4Hz,2H),7.40(d,J=8 .9Hz,2H),7.04(dd,J=8.9,2.5Hz,2H),4.34–4.05(m,4H),3.95(s,6H),1.39(t,J=7.1Hz,6H).

[0124] 3. Synthesis of MeO-PhpPACz

[0125] The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with an equal amount of MeOCz-PhP, and MeO-PhpPACz (0.310 g, 80.9%) was obtained according to the synthesis method of Me-PhpPACz. The H NMR spectrum of MeO-PhpPACz is shown in FIG12 . The H NMR spectrum data are: 1 H NMR(400MHz,DMSO-d6)δ / ppm 7.93(dd,J=12.5,8.1Hz,2H), 7.83(d,J=2.1Hz,2H), 7.70(dd,J=8.2,2.4Hz,2H), 7.38(d,J=8.9Hz,2H), 7.04(dd,J=8.9,2.0Hz,2H), 3.88(s,6H).

[0126] 4. Solar cell devices

[0127] The solar cells involved in this embodiment include perovskite solar cells and organic solar cells, specifically taking an inverted planar heterojunction perovskite solar cell as an example. FIG4 is a schematic structural diagram of the inverted planar heterojunction perovskite solar cell involved in this embodiment, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of MeO-PhpPACz or a hole transport layer; (3) a perovskite light absorption layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode.

[0128] 1) Cleaning the transparent conductive substrate ITO: the same as in Example 1;

[0129] 2) Preparation of monomolecular self-assembled layers (SAM)

[0130] A MeO-PhpPACz solution was prepared; the solution was spin-coated on a transparent conductive substrate ITO at a speed of 4000 rpm for 40 seconds; the resulting film was annealed in nitrogen at 100°C for 10 minutes;

[0131] 3) Preparation of perovskite light absorbing layer: same as in Example 1;

[0132] 4) Preparation of electron transport layer: same as in Example 1;

[0133] 5) Preparation of copper or silver electrodes: same as in Example 1;

[0134] 6) Testing

[0135] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0136] The test results are shown in Figure 13. The parameters for the best photoelectric conversion efficiency are: open circuit voltage 1.17V, short circuit current density 24.5mA / cm 2 , fill factor 85.7%, conversion efficiency 24.6%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 95% of its initial efficiency.

[0137] Example 4

[0138] The synthetic compound NapCz-PhpPACz is synthesized by the following synthesis route:

[0139] 1. Synthesis of NapCz-PhBr

[0140] The raw material 3,6-dimethylcarbazole used to synthesize MeCz-PhBr in Example 1 was replaced with an equal amount of 7H-dibenzocarbazole, and NapCz-PhBr (3.28 g, 77.7%) was obtained according to the synthesis method of MeCz-PhBr. The H NMR spectrum of NapCz-PhBr is shown in Figure 14. The H NMR spectrum data are: 1H NMR(400MHz, CDCl3)δ / ppm 9.27(d,J=8.5Hz,2H),8.09–8.01(m,2H),7.84(d,J=8.9Hz,2H),7.81–7.75(m,2H ),7.75–7.70(m,2H),7.59–7.54(m,2H),7.52(d,J=8.8Hz,2H),7.47–7.40(m,2H).

[0141] 2. Synthesis of NapCz-PhP

[0142] The raw material MeCz-PhBr used to synthesize MeCz-PhP in Example 1 was replaced with an equal amount of NapCz-PhBr, and NapCz-PhP (1.25 g, 86.8%) was obtained according to the synthesis method of MeCz-PhP. The H NMR spectrum of NapCz-PhP is shown in FIG15 . The H NMR spectrum data are: 1 HNMR(400MHz,CDCl3)δ / ppm 9.24(d,J=8.5Hz,2H),8.17–8.08(m,2H),8.08–8.01(m,2H),7.86(d,J=8.9Hz,2H ),7.77–7.66(m,4H),7.66–7.49(m,4H),4.39–4.14(m,4H),1.44(t,J=7.1Hz,6H).

[0143] 3. Synthesis of Nap-PhpPACz

[0144] The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with an equal amount of NapCz-PhP, and Nap-PhpPACz (0.405 g, 95.6%) was obtained according to the synthesis method of Me-PhpPACz. The H NMR spectrum of Nap-PhpPACz is shown in FIG16 . The H NMR spectrum data are: 1 H NMR(400MHz,DMSO-d6)δ / ppm 9.11(d,J=8.5Hz,2H),8.12(d,J=7.8Hz,2H),8.05(dd,J=12.6,8.2Hz,2H),7.95(d,J=9.0Hz,2H),7.81–7.72(m,4H),7.58(dd,J=8.0,6.0Hz,4H).

[0145] 4. Solar cell devices

[0146] The solar cells involved in this embodiment include perovskite solar cells and organic solar cells, specifically taking an inverted planar heterojunction perovskite solar cell as an example. FIG4 is a schematic structural diagram of the inverted planar heterojunction perovskite solar cell involved in this embodiment, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of Nap-PhpPACz or a hole transport layer; (3) a perovskite light absorption layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode.

[0147] 1) Cleaning the transparent conductive substrate ITO: the same as in Example 1;

[0148] 2) Preparation of monomolecular self-assembled layers (SAM)

[0149] A Nap-PhpPACz solution was prepared; the solution was spin-coated on a transparent conductive ITO substrate at a speed of 4000 rpm for 40 seconds; the resulting film was annealed in nitrogen at 100°C for 10 minutes;

[0150] 3) Preparation of perovskite light absorbing layer: same as in Example 1;

[0151] 4) Preparation of electron transport layer: same as in Example 1;

[0152] 5) Preparation of copper or silver electrodes: same as in Example 1;

[0153] 6) Testing

[0154] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0155] The test results are shown in Figure 17. The parameters for the best photoelectric conversion efficiency are: open circuit voltage 1.17V, short circuit current density 24.5mA / cm 2 , fill factor 85.9%, conversion efficiency 24.6%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 95% of its initial efficiency.

[0156] Example 5

[0157] The synthetic compound MMT-PhpPACz is synthesized by the following synthesis route:

[0158] 1. Synthesis of MMT-PhBr

[0159] The raw material 3,6-dimethylcarbazole used in the synthesis of MeCz-PhBr in Example 1 was replaced with an equal amount of 3-methyl-6-methylthiocarbazole, and MMTCz-PhBr (3.63 g, 94.9%) was obtained according to the synthesis method of MeCz-PhBr. The H NMR spectrum of MMTCz-PhBr is shown in Figure 18. The H NMR spectrum data are: 1 HNMR(400MHz,CDCl3)δ / ppm 8.07(dd,J=1.8,0.6Hz,1H),7.89(dt,J=1.6,0.8Hz,1H),7.73–7.64(m,2H),7.39(dd,J=8 .6,1.9Hz,3H),7.27(dd,J=8.5,0.6Hz,1H),7.24–7.18(m,2H),2.57(s,3H),2.53(s,3H).

[0160] 2. Synthesis of MMTCz-PhP

[0161] The MeCz-PhBr used in the synthesis of MeCz-PhP in Example 1 was replaced with an equal amount of MMTCz-PhBr, and MMTCz-PhP (1.133 g, 86.0%) was obtained according to the synthesis method of MeCz-PhP. The H NMR spectrum of MMTCz-PhP is shown in FIG19 . The H NMR spectrum data are: 1 HNMR(400MHz,CDCl3)δ / ppm 8.10–7.99(m,3H),7.89(dt,J=1.7,0.8Hz,1H),7.69–7.63(m,2H),7.42–7.32(m,3H),7.23 (dd,J=8.5,1.7Hz,1H),4.32–4.13(m,4H),2.57(s,3H),2.53(s,3H),1.40(t,J=7.0Hz,6H).

[0162] 3. Synthesis of MMT-PhpPACz

[0163] The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with an equal amount of MMTCz-PhP, and MMT-PhpPACz (0.364 g, 95.0%) was obtained according to the synthesis method of Me-PhpPACz. The H NMR spectrum of MMT-PhpPACz is shown in FIG20 . The H NMR spectrum data are: 1H NMR(400MHz,DMSO-d6)δ / ppm 8.19(dd,J=1.8,0.8Hz,1H),8.08(dt,J=1.6,0.7Hz,1H),8.00–7.90(m,2H),7.70(dd ,J=8.4,2.9Hz,2H),7.41–7.32(m,3H),7.28–7.22(m,1H),2.56(s,3H),2.48(s,3H).

[0164] 4. Solar cell devices

[0165] The solar cells involved in this embodiment include perovskite solar cells and organic solar cells, specifically taking an inverted planar heterojunction perovskite solar cell as an example. FIG4 is a schematic structural diagram of an inverted planar heterojunction perovskite solar cell involved in the present invention, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of MMT-PhpPACz or a hole transport layer; (3) a perovskite light absorption layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode.

[0166] 1) Cleaning the transparent conductive substrate ITO: the same as in Example 1;

[0167] 2) Preparation of monomolecular self-assembled layers (SAM)

[0168] A solution of MMT-PhpPACz was prepared; the solution was spin-coated on a transparent conductive substrate ITO at a speed of 4000 rpm for 40 seconds; the obtained film was annealed in nitrogen at 100°C for 10 minutes;

[0169] 3) Preparation of perovskite light absorbing layer: same as in Example 1;

[0170] 4) Preparation of electron transport layer: same as in Example 1;

[0171] In 1×10 -6 Pa vacuum, C60 was deposited on the perovskite surface.

[0172] 5) Preparation of copper or silver electrodes: same as in Example 1;

[0173] 6) Testing

[0174] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0175] The test results are shown in Figure 21. The parameters for the best photoelectric conversion efficiency are: open circuit voltage 1.16V, short circuit current density 24.3mA / cm 2 , fill factor 84.8%, conversion efficiency 23.9%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 95% of its initial efficiency.

[0176] Example 6

[0177] The synthetic compound MON-PhpPACz is synthesized by the following synthesis route:

[0178] 1. Synthesis of MONCz-PhBr

[0179] The raw material 3,6-dimethylcarbazole used in the synthesis of MeCz-PhBr in Example 1 was replaced with an equal amount of 10-methoxy-7H-benzocarbazole, and MONCz-PhBr (3.73 g, 92.7%) was obtained according to the synthesis method of MeCz-PhBr. The H NMR spectrum of MONCz-PhBr is shown in Figure 22. The H NMR spectrum data are: 1 H NMR(400MHz, CDCl3)δ / ppm 8.77(dd,J=8.3,1.1Hz,1H),8.10(d,J=2.4Hz,1H),8.05–7.98(m,1H),7.82(d,J=8.9Hz,1H),7.79–7.70(m, 3H),7.54–7.48(m,2H),7.48–7.40(m,2H),7.38(d,J=8.9Hz,1H),7.10(dd,J=8.9,2.4Hz,1H),4.04(s,3H).

[0180] 2. Synthesis of MONCz-PhP

[0181] The MeCz-PhBr used in the synthesis of MeCz-PhP in Example 1 was replaced with an equal amount of MONCz-PhBr, and MONCz-PhP (1.1 g, 79.8%) was obtained according to the synthesis method of MeCz-PhP. The H NMR spectrum of MONCz-PhP is shown in FIG23 . The H NMR spectrum data are: 1H NMR(400MHz, CDCl3)δ / ppm 8.76(dd,J=8.4,1.1Hz,1H),8.17–8.03(m,3H),8.00(dd,J=8.2,1.3Hz,1H),7.82(d,J=8.9Hz,1H),7.79–7.65(m,3H),7.5 8(d,J=8.9Hz,1H),7.55–7.43(m,2H),7.10(dd,J=9.0,2.4Hz,1H),4.35–4.14(m,4H),4.03(s,3H),1.42(t,J=7.1Hz,6H).

[0182] 3. Synthesis of MON-PhpPACz

[0183] The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with an equal amount of MONCz-PhP, and MON-PhpPACz (0.394 g, 97.7%) was obtained according to the synthesis method of Me-PhpPACz. The H NMR spectrum of MON-PhpPACz is shown in FIG24 . The H NMR spectrum data are: 1 H NMR(400MHz,DMSO-d6)δ / ppm 8.86(d,J=8.7Hz,1H),8.17–7.87(m,5H),7.81–7.70(m,3H),7.60(d,J=8.9Hz,1H),7.52(d dd,J=8.1,6.9,1.1Hz,1H),7.45(d,J=8.9Hz,1H),7.12(dd,J=8.9,2.4Hz,1H),3.98(s,3H).

[0184] 4. Solar cell devices

[0185] The solar cells involved in this embodiment include perovskite solar cells and organic solar cells, specifically taking an inverted planar heterojunction perovskite solar cell as an example. FIG4 is a schematic structural diagram of an inverted planar heterojunction perovskite solar cell involved in the present invention, which includes, from bottom to top: (1) a transparent conductive substrate ITO; (2) a monomolecular self-assembled layer (SAM) of MON-PhpPACz or a hole transport layer; (3) a perovskite light absorption layer; (4) an electron transport layer (C60); and (5) a copper or silver electrode.

[0186] 1) Cleaning the transparent conductive substrate ITO: the same as in Example 1;

[0187] 2) Preparation of monomolecular self-assembled layers (SAM)

[0188] A MON-PhpPACz solution was prepared; the solution was spin-coated on a transparent conductive substrate ITO at a speed of 4000 rpm for 40 seconds; the resulting film was annealed in nitrogen at 100°C for 10 minutes;

[0189] 3) Preparation of perovskite light absorbing layer: same as in Example 1;

[0190] 4) Preparation of electron transport layer: same as in Example 1;

[0191] 5) Preparation of copper or silver electrodes: same as in Example 1;

[0192] 6) Testing

[0193] The device structure of the planar heterojunction perovskite solar cell prepared by the above method is shown in Figure 4, with an effective area of ​​0.1 cm 2 Test conditions: spectral distribution AM1.5G, light intensity 100mW / cm 2 , AAA solar simulator (Beijing Zhuoli Hanguang Company), JV curves were measured using Keithly2400 digital source meter.

[0194] The test results are shown in Figure 25. The parameters for the best photoelectric conversion efficiency are: open circuit voltage 1.17V, short circuit current density 24.5mA / cm 2 , fill factor 85.17%, conversion efficiency 24.37%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 95% of its initial efficiency.

[0195] Comparative Example 1

[0196] Me-4PACz was used as a comparative monomolecular self-assembled layer, and the device structure was the same as that in Example 1 ( FIG. 26 ); the preparation methods of the transparent conductive substrate ITO, the monomolecular self-assembled layer or the hole transport layer, the perovskite light absorption layer, the electron transport layer, and the copper or silver electrode were the same as those in Example 1.

[0197] The test results are shown in Figures 27 and 28. The best photoelectric conversion efficiency parameters obtained with Me-4PACz as the transport layer are: open circuit voltage 1.18V, short circuit current density 25.2mA / cm 2 , fill factor 81.3%, conversion efficiency 24.1%. After 3000 hours of storage in an atmospheric environment, the device efficiency is only about 74% of the initial efficiency. In Example 1, the Me-PhpPACz achieved the best photoelectric conversion efficiency parameters: open circuit voltage 1.19V, short circuit current density 25.4mA / cm 2 , fill factor 87.1%, conversion efficiency 26.2%. After 3000 hours of storage in an atmospheric environment, the device still maintains more than 99% of its initial efficiency.

[0198] In summary, the present invention provides a self-assembled monolayer material based on conjugated linking groups, a preparation method thereof, and a solar cell. The general chemical structure of the self-assembled monolayer material based on conjugated linking groups is: The electron donor is an electron-rich group and its derivatives; L is a conjugated linking group. Introducing a conjugated linking group in place of a non-conjugated alkyl linking group in a self-assembled monolayer material effectively achieves electron delocalization, enhancing the intrinsic stability of the monolayer molecules and the hole extraction and transport capabilities. Furthermore, due to its rigid structure, the order and density of the molecular arrangement in the monolayer are significantly improved. Furthermore, the self-assembled monolayer material based on the conjugated linking group can form a dense monolayer on the surface of a conductive substrate, improving interfacial contact and passivating interfacial defects. It can also form a dipole on the surface of the conductive substrate, increasing the surface work function and promoting hole transport.

[0199] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A self-assembled monolayer material based on a conjugated linking group, characterized in that: The general chemical structure formula of the self-assembled monolayer material based on the conjugated linking group is: The electron donor is one of the electron-rich groups and their derivatives; and L is a conjugated connecting group.

2. The self-assembled monolayer material based on conjugated linking groups according to claim 1, characterized in that: The electron donor is selected from One of; Among them, R1-R 14 are independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 Alkenyl, C2-C 60 Alkynyl, C1-C 60 Alkoxy, C1-C 60 Alkylthio, C3-C 60 Cycloalkyl, C1-C 10 Heterocycloalkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocycloalkenyl, C6-C 60 Aryl, C1-C 60 One of a heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

3. The self-assembled monolayer material based on conjugated linking groups according to claim 1, characterized in that: The L is selected from One of them.

4. A method for preparing a self-assembled monolayer material based on a conjugated linking group as claimed in any one of claims 1 to 3, characterized in that: Includes steps: An electron-rich compound containing an imine structure undergoes an Ullmann reaction with a conjugated compound containing two halogen groups to obtain a first intermediate; The first intermediate is subjected to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a second intermediate containing a phosphonate; The alkoxy group in the second intermediate containing phosphonate is converted into a hydroxyl group by using trimethylsilyl bromide to obtain the self-assembled monolayer material based on the conjugated connecting group.

5. The method for preparing a self-assembled monolayer material based on a conjugated linking group according to claim 4, characterized in that: The step of subjecting the electron donor containing an imine structure to an Ullmann reaction with a conjugated linker containing two halogen groups to obtain a first intermediate comprises: In an inert gas atmosphere, the electron donor, the conjugated linker, a catalyst, a ligand, a base, and a solvent are mixed to obtain a reaction system; The reaction system is heated to a first reflux temperature and kept at this temperature for a first predetermined time to obtain the first intermediate.

6. The method for preparing a self-assembled monolayer material based on a conjugated linking group according to claim 5, characterized in that: The catalyst is at least one of copper powder, cuprous oxide, cuprous iodide, cuprous bromide and cuprous chloride; the ligand is at least one of L-proline, 18-crown ether-6, 1,2-cyclohexanediamine, 1,10-phenanthroline and oxalyl diamide ligands; the base is at least one of potassium carbonate, potassium hydroxide, potassium phosphate and potassium tert-butoxide; and the solvent is an organic solvent.

7. The method for preparing a self-assembled monolayer material based on a conjugated linking group according to claim 4, characterized in that: The step of subjecting the first intermediate to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a second intermediate containing a phosphonate comprises: In an inert gas atmosphere, the first intermediate and diethyl phosphite are mixed in a reaction system with palladium acetate as a catalyst, 1,1'-bis(diphenylphosphino)ferrocene as a ligand, triethylamine as a base, potassium acetate as an additive, and tetrahydrofuran as a solvent to obtain a mixed solution; The mixed solution is heated to a second reflux temperature and kept at this temperature for a second predetermined time to obtain the second intermediate containing the phosphonate.

8. The method for preparing a self-assembled monolayer material based on a conjugated linking group according to claim 4, characterized in that: The step of converting the alkoxy group in the second intermediate containing the phosphonate into a hydroxyl group by using trimethylsilyl bromide to obtain the self-assembled monolayer material based on the conjugated linking group comprises: Using trimethylsilyl bromide in anhydrous dichloromethane or 1,4-dioxane in an inert gas atmosphere to mix with the second intermediate containing the phosphonate to obtain a mixed solution; After the mixed solution is reacted at room temperature for a third predetermined time, the self-assembled monomer based on the conjugated linking group is obtained. Molecular layer materials.

9. A solar cell, characterized in that: The solar cell comprises a self-assembled monolayer or a hole transport layer, and the self-assembled monolayer or the hole transport layer comprises the self-assembled monolayer material based on conjugated linking groups as claimed in any one of claims 1 to 3.

10. The solar cell according to claim 9, characterized in that: The solar cell includes a perovskite solar cell or an organic solar cell.

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