CN117659083A - A self-assembled monolayer material based on conjugated connecting groups and its preparation method, solar cell - Google Patents

Abstract

The invention relates to the technical field of photoelectric devices, in particular to a self-assembled monolayer material based on a conjugated connecting group, a preparation method thereof and a solar cell, wherein the chemical structural general formula of the self-assembled monolayer material based on the conjugated connecting group is as follows:wherein the electron donor is one of an electron-rich group and a derivative thereof; l is a conjugated linking group. Introduction in self-assembled monolayer materialsThe conjugated connecting group is used for replacing the non-conjugated alkyl connecting group, so that electron delocalization can be effectively realized, and the intrinsic stability and the hole extraction and transmission capacity of the single-molecule self-assembled layer molecule are enhanced; in addition, due to the rigid structure, the order degree and the density of the molecular arrangement of the single-molecule self-assembly layer are obviously improved. The self-assembled monolayer material can form a compact single-molecule self-assembled layer on the surface of the conductive substrate, so that interface contact is improved, and interface defects are passivated; it can form dipole on the surface of conductive substrate, raise surface work function and promote hole transmission.

Description

A self-assembled monolayer material based on conjugated linking groups and its preparation method France, solar cells

Technical field

The invention relates to the technical field of optoelectronic devices, and in particular to a self-assembled monolayer material based on conjugated connecting groups, a preparation method thereof, and a solar cell.

Background technique

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

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 spontaneously formed on the solid surface by organic molecules Effective single-molecule arrays can achieve precise control of interface properties by adjusting molecular structure and functional groups. Currently widely used self-assembled molecular layer materials such as [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonate are used in common polar solvents such as methanol, ethanol, It has a certain solubility in isopropyl alcohol and N,N'-dimethylformamide, and can form single-molecule self-assembly layers by simple methods such as soaking or spin coating. However, single-molecule self-assembly layers containing alkyl chain connecting groups The material has defects such as poor stability, disordered orientation, and low arrangement density. Although great progress has been made, problems such as improving the stability of trans-perovskite solar cells and further improving photoelectric conversion efficiency still need to be solved.

Contents of the invention

In view of the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a self-assembled monolayer material based on conjugated connecting groups and a preparation method thereof, and a solar cell, aiming to solve the existing problems of containing alkyl chain connecting groups. Single-molecule self-assembly layer materials have defects such as poor stability, chaotic orientation, and low arrangement density.

The technical solution of the present invention is as follows:

A self-assembled monolayer material based on conjugated connecting groups. The general chemical structure formula of the self-assembled monolayer material based on conjugated connecting groups is:

Among them, the electron donor is one of electron-rich groups and their derivatives; L is a conjugated connecting group.

A method for preparing self-assembled monolayer materials based on conjugated linking groups, including the steps:

Ullmann reaction occurs between an electron-rich compound containing an imine structure and 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 ester;

Trimethylsilyl bromide is used to convert the alkoxy group in the second intermediate containing phosphonate ester into a hydroxyl group to obtain the self-assembled monolayer material based on the conjugated linking group.

A solar cell, characterized in that the solar cell includes a self-assembled monolayer or a hole transport layer, and the self-assembled monolayer or hole transport layer includes the self-assembled monolayer based on conjugated connecting groups. Molecular layer materials.

Beneficial effects: The present invention provides a self-assembled monolayer material based on conjugated connecting groups, a preparation method thereof, and a solar cell. The general chemical structure formula of the self-assembled monolayer material based on conjugated connecting groups is: : Among them, the electron donor is one of electron-rich groups and their derivatives; L is a conjugated connecting group. Introducing conjugated linking groups to replace non-conjugated alkyl linking groups in self-assembled monolayer materials can effectively achieve electron delocalization and enhance the intrinsic stability and hole extraction and transport capabilities of the single-molecule self-assembled layer molecules. ; In addition, due to its rigid structure, the order and density of molecular arrangement in the single-molecule self-assembly layer are significantly improved. Moreover, the self-assembled monolayer material based on conjugated connecting groups can form a dense single-molecule self-assembled layer on the surface of the conductive substrate, improve interface contact, and passivate interface defects; it can form dipoles on the surface of the conductive substrate. ions, improve the surface work function and promote hole transport.

Description of drawings

Figure 1 is a hydrogen nuclear magnetic resonance spectrum of MeCz-PhBr in Example 1;

Figure 2 is the hydrogen nuclear magnetic resonance spectrum of MeCz-PhP in Example 1;

Figure 3 is the hydrogen nuclear magnetic resonance spectrum of Me-PhpPACz in Example 1;

Figure 4 is a schematic diagram of the structure of a trans planar heterojunction perovskite solar cell;

Figure 5 is the J-V curve of a perovskite solar cell based on the transmission layer Me-PhpPACz;

Figure 6 is a hydrogen nuclear magnetic resonance spectrum of Cz-PhBr in Example 2;

Figure 7 is the hydrogen nuclear magnetic resonance spectrum of Cz-PhP in Example 2;

Figure 8 is the hydrogen nuclear magnetic resonance spectrum of PhpPACz in Example 2;

Figure 9 is a J-V curve of a perovskite solar cell based on the transmission layer PhpPACz in Example 2;

Figure 10 is a hydrogen nuclear magnetic resonance spectrum of MeOCz-PhBr in Example 3;

Figure 11 is the hydrogen nuclear magnetic resonance spectrum of MeOCz-PhP in Example 3;

Figure 12 is the hydrogen nuclear magnetic resonance spectrum of MeO-PhpPACz in Example 3;

Figure 13 is the J-V curve of a perovskite solar cell based on the transmission layer MeO-PhpPACz;

Figure 14 is the hydrogen nuclear magnetic resonance spectrum of NapCz-PhBr in Example 4;

Figure 15 is the hydrogen nuclear magnetic resonance spectrum of NapCz-PhP in Example 4;

Figure 16 is the hydrogen nuclear magnetic resonance spectrum of Nap-PhpPACz in Example 4;

Figure 17 is the J-V curve of a perovskite solar cell based on the transmission layer Nap-PhpPACz;

Figure 18 is the hydrogen nuclear magnetic resonance spectrum of MMT-PhBr in Example 5;

Figure 19 is the hydrogen nuclear magnetic resonance spectrum of MMT-PhP in Example 5;

Figure 20 is the hydrogen nuclear magnetic resonance spectrum of MMT-PhpPACz in Example 5;

Figure 21 is the J-V curve of a perovskite solar cell based on the transmission layer MMT-PhpPACz;

Figure 22 is a hydrogen nuclear magnetic resonance spectrum of MONCz-PhBr in Example 6;

Figure 23 is the hydrogen nuclear magnetic resonance spectrum of MONCz-PhP in Example 6;

Figure 24 is the hydrogen nuclear magnetic resonance spectrum of MON-PhpPACz in Example 6;

Figure 25 is the J-V curve of a perovskite solar cell based on the transmission layer MON-PhpPACz;

Figure 26 is a structural diagram of a perovskite device containing a single molecular layer in Comparative Example 1;

Figure 27 is the I-V curve of the perovskite solar cell of Comparative Example 1;

Figure 28 is a stability test chart of the perovskite solar cell device of Comparative Example 1.

Detailed ways

The present invention provides a self-assembled monolayer material based on conjugated connecting groups, a preparation method thereof, and a solar cell. In order to make the purpose, technical solutions, and effects of the present invention clearer and clearer, the present invention is further described in detail below. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

Self-assembled molecular layers can serve as intermediate connectors to achieve tight integration between layers, regulate interface energy levels, suppress interface defects, and promote charge extraction and transport. Currently widely used self-assembled monolayer materials usually have the following structure: 1. Head groups, such as carbazole, phenothiazine and other electron donors, can passivate interface defects, regulate energy levels, and achieve efficient charge extraction and transport ; 2. Linking groups, such as alkyl chains of different lengths, provide materials with self-assembly flexibility; 3. Anchor groups, such as phosphonic acid, can form effective covalent bonds with commonly used transparent conductive substrates through chemical reactions Bonding has been proven to be the anchoring group that binds most closely to a specific metal oxide among similar groups.

However, existing single-molecule self-assembly layer materials containing alkyl chain connecting groups have shortcomings such as poor stability, chaotic orientation, and low arrangement density. Although great progress has been made, it is still difficult to improve the stability of solar cell devices and further enhance photovoltaic efficiency. Issues such as conversion efficiency still need to be resolved.

Based on this, as shown in Figure 1, the present invention provides a self-assembled monolayer material based on conjugated connecting groups. The general chemical structure formula of the self-assembled monolayer material based on conjugated connecting groups is:

Among them, the electron donor is one of electron-rich groups and their derivatives; L is a conjugated connecting group.

In this embodiment, conjugated linking groups are introduced into self-assembled monolayer materials to replace non-conjugated alkyl linking groups, and a series of self-assembled monolayer materials based on conjugated linking groups are constructed, aiming to enhance Its intrinsic stability improves self-assembly performance and hole extraction and transport capabilities. Comparison of cyclic voltammetry and nuclear magnetic detection before and after illumination showed that compared with single-molecule self-assembled layer materials based on non-conjugated linking groups, the self-assembled monolayer materials based on conjugated linking groups have higher electrical potential. Chemical and light stability, dissolve it in an alcohol solvent, and use spin coating to form a single-molecule self-assembly layer on the surface of a conductive substrate. XPS surface scanning confirmed that it formed a tighter single-molecule self-assembly layer. 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.

Specifically, the self-assembled monolayer material based on conjugated linking groups provided by this embodiment has the following beneficial effects: (1) The self-assembled monolayer material based on conjugated linking groups has obvious electron delocalization. , has high intrinsic stability; (2) the self-assembled monolayer material based on conjugated connecting groups can form a denser self-assembly layer on a conductive substrate; (3) can effectively regulate conductivity The surface work function of the substrate; (4) can make the single-molecule self-assembly layer have stronger hole extraction and transport capabilities.

In some embodiments, the electron donor in the general chemical structure formula is carbazole, phenothiazine, phenoxazine, diphenylamine and other electron-rich groups and their derivatives; L in the general chemical structure formula It is a conjugated linking group for benzene, biphenyl, anthracene, phenanthrene, pyrene, pyridine, pyrimidine, furan, thiophene, quinoline, etc. The self-assembled monolayer material based on the conjugated connecting group forms a self-assembled monolayer on the transparent conductive substrate during the spin coating film-forming process through the anchoring effect of the phosphate group on the metal oxide, which is adjustable. The surface work function of conductive glass improves the interface energy level matching; at the same time, the conjugated connecting groups in this type of material can enhance the intermolecular interaction within the layer and form a denser single-molecule self-assembly layer; and the conjugated connecting groups have Strong electrical conductivity, which 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 conjugated linking group L respectively, this type of material has excellent optical and electrical stability.

In some embodiments, the electron donor is selected from

one of;

Among them, R ₁ to R ₁₄ are independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, C ₁ - C ₆₀ alkyl, C ₂ -C ₆₀ alkenyl, C ₂ -C ₆₀ alkynyl, C ₁ -C ₆₀ alkoxy, C ₃ -C ₆₀ cycloalkyl, C ₁ -C ₁₀ heterocycloalkyl, C ₃ -C ₁₀ cycloalkenyl, C ₁ -C ₁₀ heterocycloalkenyl, C ₆ -C ₆₀ aryl, C ₁ -C ₆₀ heteroaryl, monovalent non-aromatic condensed polycyclic group, monovalent non-aromatic condensed heteropolycyclic group One of base, biphenyl, and terphenyl.

In some embodiments, the L is selected from

one of them.

In addition, the present invention also provides a method for preparing a self-assembled monolayer material based on conjugated connecting groups, including the steps:

Step S10: Perform Ullmann reaction between an electron-rich compound containing an imine structure and a conjugated compound containing two halogen groups to obtain a first intermediate;

Step S20: The first intermediate is subjected to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a second intermediate containing a phosphonate ester;

Step S30: Use trimethylsilyl bromide to convert the alkoxy group in the second intermediate containing phosphonate ester into a hydroxyl group to obtain the self-assembled monolayer material based on the conjugated connecting group.

In this embodiment, an electron donor containing an imine (-NH-) structure is first conjugated with a conjugated electron donor containing two halogen groups -X ₁ , -X ₂ (-I, -Br, -Cl, -F). The linker X ₁ -LX ₂ undergoes Ullmann reaction to obtain the first intermediate; then, the first intermediate is subjected to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain the third phosphonate-containing ester. Two intermediates; finally, the alkoxy group (-OR) in the phosphonate ester in the second intermediate is converted into a hydroxyl group (-OH) through trimethylsilyl bromide (TMSBr) to obtain a self-conjugated linking group. Assembling monolayer materials.

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

In some embodiments, the step of performing an Ullmann reaction between an electron donor containing an imine structure and a conjugated linker containing two halogen groups to obtain a first intermediate includes: in an inert gas atmosphere , the electron donor, the conjugated connector, the catalyst, the ligand, the base, and the solvent are mixed to obtain a reaction system; the reaction system is heated to the first reflux temperature and maintained for a first predetermined time to obtain the first intermediate.

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

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

In some embodiments, the step of subjecting the first intermediate to a carbon-phosphine bond coupling reaction catalyzed by palladium to obtain a second intermediate containing a phosphonate ester includes: converting the first intermediate in an inert gas atmosphere. and diethyl phosphite in a reaction system in which palladium acetate is the catalyst, 1,1`-bis(diphenylphosphine)ferrocene is the ligand, triethylamine is the base, potassium acetate is the additive, and tetrahydrofuran is the solvent. Mix to obtain a mixed solution; heat the mixed solution to a second reflux temperature and maintain the temperature for a second predetermined time to obtain the second intermediate containing phosphonate ester.

As an example, the first intermediate (1 equivalent) and diethyl phosphite (1 equivalent) in the middle of the inert gas range are in palladium acetate (0.025 equivalent) as the catalyst, 1,1`-bis(diphenylphosphine) ) ferrocene (0.05 equivalent) as the ligand, triethylamine (1.2 equivalent) as the base, potassium acetate (0.1 equivalent) as the additive, tetrahydrofuran as the solvent, mix and heat to the second reflux temperature and maintain the After two predetermined times, a second intermediate containing phosphonate ester is obtained; 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 .

In some embodiments, the alkoxy group in the second intermediate containing the phosphonate ester is converted into a hydroxyl group using trimethylsilyl bromide to obtain the self-assembled monolayer based on the conjugated linking group. The steps of making materials include: using trimethylsilyl bromide in anhydrous methylene chloride or 1,4-dioxane to mix with the second intermediate containing phosphonate ester in an inert gas atmosphere to obtain a mixture liquid; after the mixed liquid reacts at room temperature for a third predetermined time, the self-assembled monolayer material based on conjugated connecting groups is obtained.

By way of example, trimethylsilyl bromide (4 equivalents) is mixed with the phosphonate-containing second intermediate in anhydrous dichloromethane or 1,4-dioxane under an inert gas atmosphere, Then, after reacting at room temperature for 12-24 hours, it is subsequently quenched with methanol or water to convert the alkoxy group contained in the phosphonate ester in the second intermediate into a hydroxyl group to obtain the conjugated linking group. self-assembled monolayer materials.

In addition, the present invention also provides a solar cell. The solar cell includes a self-assembled monomolecular layer or a hole transport layer. The self-assembled monomolecular layer or hole transport layer includes the self-assembled monomolecular layer or hole transport layer based on the conjugated connecting group. Assembling monolayer materials.

In this embodiment, the self-assembled monolayer material based on conjugated connecting groups is used in solar cells. This type of material can effectively improve the quality of the single-molecule self-assembled layer and enhance the stability and hole extraction capability. , improved the interface contact and energy level arrangement, and realized a solar cell with high efficiency and good stability.

In some embodiments, the solar cell includes one or more of a perovskite solar cell or an organic solar cell; the perovskite solar cell is a lead-based compound of ABX ₃ . The electron donor in the self-assembled monolayer material based on the conjugated linking group can directly contact the lower interface of the perovskite, and the passivation group is introduced through reasonable molecular modification, which can passivate the interface defects and facilitate the formation of High quality perovskite film.

Specifically, the self-assembled monolayer material based on conjugated connecting groups is used on the surface of conductive glass, perovskite, tin oxide, titanium oxide, aluminum oxide or nickel oxide, and the self-assembled monolayer based on the self-assembled monolayer is produced. Materials for solar cells.

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

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

In a preferred embodiment, the perovskite solar cell is a trans perovskite solar cell; single-molecule self-assembly layer materials containing conjugated connecting groups are applied to trans perovskite solar cell devices. , improve the hole extraction capability, improve the stability of reactive perovskite solar cells, and achieve high-efficiency devices with high open circuit voltage and high fill factor. At the same time, this type of material has the advantages of short preparation process and low consumption, which is conducive to further realizing the large-area and low-cost preparation and commercialization of trans-perovskite solar cell devices. Single-molecule self-assembly layer materials based on conjugated groups have high intrinsic stability and hole extraction capabilities. Trans-perovskite solar cells prepared based on such materials have good repeatability, high photoelectric conversion efficiency, and device The advantage of good performance and stability.

Specifically, the self-assembled monolayer material based on conjugated connecting groups can effectively adjust the surface work function of conductive glass, improve interface contact, promote charge conduction, and achieve efficient and stable trans-perovskite solar cells. Based on the strong anchoring effect of phosphate groups on common metal oxides, this type of material can also be widely used in the fields of optoelectronic devices such as perovskite light-emitting diodes, organic solar cells, organic light-emitting diodes, and field-effect transistors.

The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above contents of the present invention all belong to the present invention. scope of protection.

Example 1

The compound Me-PhpPACz is synthesized, and its synthesis route is as follows:

1.Synthesis of MeCz-PhBr

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

2.Synthesis of MeCz-PhP

Palladium acetate (16.8 mg, 0.075 mmol), 1,1'-bis(diphenylphosphine)ferrocene (83.2 mg, 0.15 mmol), potassium acetate (29.4 mg, 0.3 mmol) and MeCz-PhBr (1.05 g , 3mmol) was added to a dried 100mL double-necked flask. Triethylamine (364 mg, 3.6 mmol) and 30 mL of tetrahydrofuran bubbled 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 was continued at the boil for 12 hours. After cooling to room temperature, the reaction mixture was filtered through diatomaceous earth and rinsed with tetrahydrofuran. The solvent was removed from the filtrate using a rotary evaporator. The obtained crude product was purified by silica gel column chromatography to obtain a white solid product (1.15g, 94%), which is MeCz-PhP. The hydrogen nuclear magnetic resonance spectrum of MeCz-PhP is shown in Figure 2. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) δ8.07-7.98 (m, 2H), 7.89 (d, J = 1.8Hz, 2H),7.74-7.65(m,2H),7.37(d,J＝8.4Hz,2H),7.22(dd,J＝8.5,1.8Hz,2H),4.35-4.09(m,4H),2.54(s ,6H),1.40(t,J=7.1Hz,6H), indicating that MeCz-PhP was successfully synthesized.

3.Synthesis of Me-PhpPACz

Under an argon atmosphere, 20 mL of methylene chloride was added to a 50 mL double-necked flask containing MeCz-PhP (0.407 g, 1 mmol). Under stirring, trimethylsilyl bromide (0.612g, 4mmol) was added dropwise, and the reaction mixture was allowed to stir for 12 hours. Transfer the reaction mixture to a 100 mL round-bottomed flask, use a rotary evaporator to remove the solvent, and then add 20 mL of methanol and continue stirring for 4 hours. After the reaction was completed, the solvent was removed again using a rotary evaporator to obtain a crude product, which was further recrystallized using a methanol/dichloromethane/diethyl ether system to obtain a white solid product (0.350 g, 99.5%). The hydrogen nuclear magnetic resonance spectrum of Me-PhpPACz is shown in Figure 3. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, DMSO-d ₆ ) δ8.05-7.90 (m, 4H), 7.70 (dd, J = 8.4 ,2.9Hz,2H),7.35(d,J＝8.4Hz,2H),7.23(dd,J＝8.5,1.3Hz,2H),2.48(s,6H), indicating that Me-PhpPACz was successfully synthesized.

4. Use the prepared Me-PhpPACz in solar cells

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

1) Clean the transparent conductive substrate ITO

Ultrasonicate the etched transparent conductive substrate ITO in detergent, deionized water, absolute ethanol, acetone, and isopropyl alcohol for 15 minutes. After taking it out, blow it dry with clean air, put it in the oven, and bake it at 120°C. Dry for 8 hours, UV/Ozone treatment for 30 minutes.

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of Me-PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 s; the prepared film is annealed in nitrogen at 100°C for 10 minutes.

3) Preparation of perovskite light-absorbing layer

Any ABX ₃ has a perovskite structure, where A is any organic cation, such as formamidine (FA), methylamine (MA), etc.; B is any metal cation, such as lead, tin, etc. _; Spin coating is performed on ITO through two steps, specifically 1000rpm for 10s and 6000rpm for 20s (1000rpm for 10s and 6000rpm for 20s). When 5 seconds are left, chlorobenzene is dropped in the middle of the substrate, and the film is annealed at 100 °C for 0.5 h.

4) Preparation of electron transport layer

C60 was deposited on the perovskite surface under a vacuum of 1×10 ^-6 Pa.

5) Preparation of copper or silver electrodes

Under a vacuum degree of 1×10 ^-6 Pa, Copper or silver electrodes were prepared by rate evaporation deposition, and the electrode thickness was controlled to ∼100 nm.

6) Test

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

The test results are shown in Figure 5. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.19V, short circuit current density 25.4mA/cm ² , fill factor 87.1%, and conversion efficiency 26.2%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 99% of its initial efficiency.

Example 2

Synthesize compound PhpPACz, its synthesis route is as follows:

1.Synthesis of Cz-PhBr

The raw material for synthesizing MeCz-PhBr in Example 1, 3,6-dimethylcarbazole, 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 hydrogen nuclear magnetic resonance spectrum of Cz-PhBr is shown in Figure 6. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

2.Synthesis of Cz-PhP

The raw material MeCz-PhBr used for the synthesis of MeCz-PhP in Example 1 was replaced by an equal amount of Cz-PhBr, and Cz-PhP (0.962g, 84.5%) was obtained according to the synthesis method of MeCz-PhP. The hydrogen nuclear magnetic resonance spectrum of Cz-PhP is shown in Figure 7. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, CDCl ₃ ) 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(ddd,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).

3.Synthesis of PhpPACz

The raw material MeCz-PhP used for synthesizing Me-PhpPACz in Example 1 was replaced by an equal amount of Cz-PhP, and PhpPACz (0.310 g, 95.8%) was obtained according to the synthesis method of Me-PhpPACz. The hydrogen nuclear magnetic resonance spectrum of PhpPACz is shown in Figure 8. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, DMSO-d ₆ ) δ/ppm 8.26 (d, J = 7.7 Hz, 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).

4. Preparation of solar cell devices

The solar cells involved in this embodiment involve perovskite solar cells and organic solar cells, specifically taking trans planar heterojunction perovskite solar cells as an example. Figure 4 is a schematic structural diagram of the trans planar heterojunction perovskite solar cell involved in this embodiment, which includes from bottom to top: (1) transparent conductive substrate ITO; (2) single-molecule self-assembly layer of PhpPACz (SAM) or hole transport layer; (3) Perovskite light-absorbing layer; (4) Electron transport layer (C60); (5) Copper or silver electrode.

1) Cleaning the transparent conductive substrate ITO: the same as in Embodiment 1;

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; anneal the prepared film at 100°C in nitrogen for 10 minutes;

3) Preparation of perovskite light-absorbing layer: same as Example 1;

4) Preparation of the electron transport layer: the same as in Example 1;

5) Preparation of copper or silver electrodes: the same as in Example 1;

6) Test

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

The test results are shown in Figure 9. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.17V, short circuit current density 24.6mA/cm2, fill factor 84.6%, and conversion efficiency 24.3%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 95% of its initial efficiency.

Example 3

The compound MeO-PhpPACz is synthesized, and its synthesis route is as follows:

1.Synthesis of MeOCz-PhBr

The raw material 3,6-dimethylcarbazole used for the synthesis of MeCz-PhBr in Example 1 was replaced with an equal amount of 3,6-dimethoxycarbazole, and MeOCz-PhBr was obtained according to the synthesis method of MeCz-PhBr ( 3.55g, 92.9%). The hydrogen nuclear magnetic resonance spectrum of MeOCz-PhBr is shown in Figure 10. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, CDCl ₃ ) 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).

2.Synthesis of MeOCz-PhP

The raw material MeCz-PhBr used for the synthesis of MeCz-PhP in Example 1 was replaced by 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 hydrogen nuclear magnetic resonance spectrum of Cz-PhP is shown in Figure 11. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

3.Synthesis of MeO-PhpPACz

The raw material MeCz-PhP used for synthesizing Me-PhpPACz in Example 1 was replaced with equal amounts of MeOCz-PhP, and MeO-PhpPACz (0.310 g, 80.9%) was obtained according to the synthesis method of Me-PhpPACz. The hydrogen nuclear magnetic resonance spectrum of MeO-PhpPACz is shown in Figure 12. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, DMSO-d ₆ ) 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).

4. Solar cell devices

The solar cells involved in this embodiment involve perovskite solar cells and organic solar cells, specifically taking trans planar heterojunction perovskite solar cells as an example. Figure 4 is a schematic structural diagram of the trans planar heterojunction perovskite solar cell involved in this embodiment. From bottom to top, it includes: (1) transparent conductive substrate ITO; (2) single molecule self-contained structure of MeO-PhpPACz Assembly layer (SAM) or hole transport layer; (3) Perovskite light-absorbing layer; (4) Electron transport layer (C60); (5) Copper or silver electrode.

1) Cleaning the transparent conductive substrate ITO: the same as in Embodiment 1;

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of MeO-PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; anneal the prepared film at 100°C in nitrogen for 10 minutes;

3) Preparation of the perovskite light-absorbing layer: the same as in Example 1;

4) Preparation of electron transport layer: same as Example 1;

5) Preparation of copper or silver electrodes: the same as in Example 1;

6) Test

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

The test results are shown in Figure 13. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.17V, short circuit current density 24.5mA/cm ² , fill factor 85.7%, and conversion efficiency 24.6%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 95% of its initial efficiency.

Example 4

Synthesize compound NapCz-PhpPACz, its synthesis route is as follows:

1.Synthesis of NapCz-PhBr

The raw material 3,6-dimethylcarbazole for synthesizing MeCz-PhBr in Example 1 was replaced with 7H-dibenzocarbazole in an equal amount, and NapCz-PhBr (3.28g, 77.7%). The hydrogen nuclear magnetic resonance spectrum of NapCz-PhBr is shown in Figure 14. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, CDCl ₃ ) 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＝8.8 Hz,2H),7.47-7.40(m,2H).

2.Synthesis of NapCz-PhP

The raw material MeCz-PhBr used for synthesizing 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 hydrogen nuclear magnetic resonance spectrum of NapCz-PhP is shown in Figure 15. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

3.Synthesis of Nap-PhpPACz

The raw material MeCz-PhP used for synthesizing 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 hydrogen nuclear magnetic resonance spectrum of Nap-PhpPACz is shown in Figure 16. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, DMSO-d ₆ ) 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).

4. Solar cell devices

The solar cells involved in this embodiment involve perovskite solar cells and organic solar cells, specifically taking trans planar heterojunction perovskite solar cells as an example. Figure 4 is a schematic structural diagram of the trans planar heterojunction perovskite solar cell involved in this embodiment, which includes from bottom to top: (1) transparent conductive substrate ITO; (2) single-molecule self-contained Nap-PhpPACz Assembly layer (SAM) or hole transport layer; (3) Perovskite light-absorbing layer; (4) Electron transport layer (C60); (5) Copper or silver electrode.

1) Cleaning the transparent conductive substrate ITO: the same as in Embodiment 1;

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of Nap-PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; anneal the prepared film at 100°C in nitrogen for 10 minutes;

3) Preparation of perovskite light-absorbing layer: same as Example 1;

4) Preparation of the electron transport layer: the same as in Example 1;

5) Preparation of copper or silver electrodes: the same as in Example 1;

6) Test

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

The test results are shown in Figure 17. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.17V, short circuit current density 24.5mA/cm ² , fill factor 85.9%, and conversion efficiency 24.6%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 95% of its initial efficiency.

Example 5

The compound MMT-PhpPACz is synthesized, and its synthesis route is as follows:

1.Synthesis of MMT-PhBr

The raw material 3,6-dimethylcarbazole used for the synthesis of MeCz-PhBr in Example 1 was replaced with 3-methyl-6-methylthiocarbazole in an equal amount, and MMTCz- was obtained according to the synthesis method of MeCz-PhBr. PhBr (3.63g, 94.9%). The hydrogen nuclear magnetic resonance spectrum of MMTCz-PhBr is shown in Figure 18. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

2.Synthesis of MMTCz-PhP

The raw material MeCz-PhBr used for the synthesis of MeCz-PhP in Example 1 was replaced with equal amounts of MMTCz-PhBr, and MMTCz-PhP (1.133 g, 86.0%) was obtained according to the synthesis method of MeCz-PhP. The hydrogen nuclear magnetic resonance spectrum of MMTCz-PhP is shown in Figure 19. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

3.Synthesis of MMT-PhpPACz

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 (0.364g, 95.0%) was obtained according to the synthesis method of Me-PhpPACz. The hydrogen nuclear magnetic resonance spectrum of MMT-PhpPACz is shown in Figure 20. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, DMSO-d ₆ ) 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).

4. Solar cell devices

The solar cells involved in this embodiment involve perovskite solar cells and organic solar cells, specifically taking trans planar heterojunction perovskite solar cells as an example. Figure 4 is a schematic structural diagram of the trans planar heterojunction perovskite solar cell involved in the present invention, which includes from bottom to top: (1) transparent conductive substrate ITO; (2) single-molecule self-assembly of MMT-PhpPACz layer (SAM) or hole transport layer; (3) perovskite light-absorbing layer; (4) electron transport layer (C60); (5) copper or silver electrode.

1) Cleaning the transparent conductive substrate ITO: the same as in Embodiment 1;

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of MMT-PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; anneal the prepared film at 100°C in nitrogen for 10 minutes;

3) Preparation of perovskite light-absorbing layer: same as Example 1;

4) Preparation of electron transport layer: same as Example 1;

C60 was deposited on the perovskite surface under a vacuum of 1×10 ^-6 Pa.

5) Preparation of copper or silver electrodes: the same as in Example 1;

6) Test

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

The test results are shown in Figure 21. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.16V, short circuit current density 24.3mA/cm ² , fill factor 84.8%, and conversion efficiency 23.9%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 95% of its initial efficiency.

Example 6

Synthesize compound MON-PhpPACz, its synthesis route is as follows:

1.Synthesis of MONCz-PhBr

The raw material for synthesizing MeCz-PhBr in Example 1, 3,6-dimethylcarbazole, was replaced with an equal amount of 10-methoxy-7H-benzocarbazole, and MONCz- was obtained according to the synthesis method of MeCz-PhBr. PhBr (3.73g, 92.7%). The hydrogen nuclear magnetic resonance spectrum of MONCz-PhBr is shown in Figure 22. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, CDCl ₃ ) 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).

2.Synthesis of MONCz-PhP

The raw material MeCz-PhBr used for synthesizing MeCz-PhP in Example 1 was replaced with MONCz-PhBr in equal amounts, and MONCz-PhP (1.1 g, 79.8%) was obtained according to the synthesis method of MeCz-PhP. The hydrogen nuclear magnetic resonance spectrum of MONCz-PhP is shown in Figure 23. The hydrogen nuclear magnetic resonance spectrum data is: ¹ H NMR (400MHz, CDCl ₃ ) 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),7.58(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).

3.Synthesis of MON-PhpPACz

The raw material MeCz-PhP used to synthesize Me-PhpPACz in Example 1 was replaced with MONCz-PhP in equal amounts, and MON-PhpPACz (0.394g, 97.7%) was obtained according to the synthesis method of Me-PhpPACz. The hydrogen nuclear magnetic resonance spectrum of MON-PhpPACz is shown in Figure 24. The hydrogen nuclear magnetic resonance spectrum data are: ¹ H NMR (400MHz, DMSO-d ₆ ) 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(ddd,J＝8.1,6.9,1.1Hz,1H),7.45(d,J＝8.9 Hz, 1H), 7.12 (dd, J = 8.9, 2.4Hz, 1H), 3.98 (s, 3H).

4. Solar cell devices

The solar cells involved in this embodiment involve perovskite solar cells and organic solar cells, specifically taking trans planar heterojunction perovskite solar cells as an example. Figure 4 is a schematic structural diagram of the trans planar heterojunction perovskite solar cell involved in the present invention, which includes from bottom to top: (1) transparent conductive substrate ITO; (2) single-molecule self-assembly of MON-PhpPACz layer (SAM) or hole transport layer; (3) perovskite light-absorbing layer; (4) electron transport layer (C60); (5) copper or silver electrode.

1) Cleaning the transparent conductive substrate ITO: the same as in Embodiment 1;

2) Preparation of single-molecule self-assembly layer (SAM)

Prepare a solution of MON-PhpPACz; spin-coat the solution on the transparent conductive substrate ITO at a rotation speed of 4000 rpm for 40 seconds; anneal the resulting film at 100°C in nitrogen for 10 minutes;

3) Preparation of perovskite light-absorbing layer: same as Example 1;

4) Preparation of the electron transport layer: the same as in Example 1;

5) Preparation of copper or silver electrodes: the same as in Example 1;

6) Test

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

The test results are shown in Figure 25. The optimal photoelectric conversion efficiency parameters are: open circuit voltage 1.17V, short circuit current density 24.5mA/cm ² , fill factor 85.17%, and conversion efficiency 24.37%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 95% of its initial efficiency.

Comparative example 1

Using Me-4PACz as the comparative single-molecule self-assembly layer, the device structure is the same as in Example 1 (Figure 26); transparent conductive substrate ITO, single-molecule self-assembly layer or hole transport layer, perovskite light-absorbing layer, electron transport layer The preparation method of the copper or silver electrode is the same as in Example 1.

The test results are shown in Figure 27 and Figure 28. Me-4PACz obtains the best photoelectric conversion efficiency parameters for the transmission layer: open circuit voltage 1.18V, short circuit current density 25.2mA/cm ² , fill factor 81.3%, and conversion efficiency 24.1%. After the device was stored in the atmospheric environment for 3,000 hours, the device efficiency was only approximately 74% of the initial efficiency. In Example 1, the optimal photoelectric conversion efficiency parameters obtained by Me-PhpPACz are: open circuit voltage 1.19V, short circuit current density 25.4mA/cm ² , filling factor 87.1%, and conversion efficiency 26.2%. After the device was stored in the atmospheric environment for 3,000 hours, it still maintained more than 99% of its initial efficiency.

In summary, the present invention provides a self-assembled monolayer material based on conjugated connecting groups, a preparation method thereof, and a solar cell. The chemical structure of the self-assembled monolayer material based on conjugated connecting groups is generally The formula is: Among them, the electron donor is an electron-rich group and its derivatives; L is a conjugated connecting group. Introducing conjugated linking groups to replace non-conjugated alkyl linking groups in self-assembled monolayer materials can effectively achieve electron delocalization and enhance the intrinsic stability and hole extraction and transport capabilities of the single-molecule self-assembled layer molecules. ; In addition, due to its rigid structure, the order and density of molecular arrangement in the single-molecule self-assembly layer are significantly improved. Moreover, the self-assembled monolayer material based on conjugated connecting groups can form a dense single-molecule self-assembled layer on the surface of the conductive substrate, improve interface contact, and passivate interface defects; it can form dipoles on the surface of the conductive substrate. ions, improve the surface work function and promote hole transport.

It should be understood that the application of the present invention is not limited to the above examples. Those of ordinary skill in the art can make improvements or changes based on the above descriptions. All these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims (10)

1. A self-assembled monolayer material based on conjugated connecting groups, characterized in that the general chemical structure formula of the self-assembled monolayer material based on conjugated connecting groups is: Among them, the electron donor is one of electron-rich groups and their derivatives; 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, R ₁ to R ₁₄ are independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, C ₁ - C ₆₀ alkyl, C ₂ -C ₆₀ alkenyl, C ₂ -C ₆₀ alkynyl, C ₁ -C ₆₀ alkoxy, C ₃ -C ₆₀ cycloalkyl, C ₁ -C ₁₀ heterocycloalkyl, C ₃ -C ₁₀ cycloalkenyl, C ₁ -C ₁₀ heterocycloalkenyl, C ₆ -C ₆₀ aryl, C ₁ -C ₆₀ heteroaryl, monovalent non-aromatic condensed polycyclic group, monovalent non-aromatic condensed heteropolycyclic group One of base, biphenyl, and terphenyl. 3. The self-assembled monolayer material based on conjugated connecting 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 conjugated connecting groups according to any one of claims 1-3, characterized in that it includes the steps: Ullmann reaction occurs between an electron-rich compound containing an imine structure and 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 ester; Trimethylsilyl bromide is used to convert the alkoxy group in the second intermediate containing phosphonate ester into a hydroxyl group to obtain the self-assembled monolayer material based on the conjugated linking group. 5. The preparation method of self-assembled monolayer materials based on conjugated connecting groups according to claim 4, characterized in that, the electron donor containing an imine structure is combined with a covalent polymer containing two halogen groups. The steps of Ullmann reaction of the yoked linker to obtain the first intermediate include: In an inert gas atmosphere, the electron donor, the conjugated connector, the catalyst, the ligand, the base, and the solvent are mixed to obtain a reaction system; The reaction system is heated to the first reflux temperature and maintained for a first predetermined time to obtain the first intermediate. 6. The preparation method of self-assembled monolayer material based on conjugated connecting groups according to claim 5, characterized in that the catalyst is copper powder, cuprous oxide, cuprous iodide, cuprous bromide , at least one of cuprous chloride; the ligand is L-proline, 18-crown ether-6, 1,2-cyclohexanediamine, 1,10-phenanthroline, oxalyldiamide At least one of the ligands; the base is at least one of potassium carbonate, potassium hydroxide, potassium phosphate, and potassium tert-butoxide; the solvent is an organic solvent. 7. The method for preparing a self-assembled monolayer material based on conjugated linking groups according to claim 4, characterized in that the first intermediate is subjected to a palladium-catalyzed carbon-phosphine bond coupling reaction to obtain a compound containing The steps of the second intermediate of phosphonate ester include: The first intermediate and diethyl phosphite are mixed in an inert gas atmosphere with palladium acetate as the catalyst, 1,1ˋ-bis(diphenylphosphine)ferrocene as the ligand, triethylamine as the base, and potassium acetate. Mix in a reaction system with tetrahydrofuran as the additive and tetrahydrofuran as the solvent to obtain a mixed solution; The mixed solution is heated to a second reflux temperature and maintained for a second predetermined time to obtain the second intermediate containing phosphonate ester. 8. The preparation method of self-assembled monolayer materials based on conjugated linking groups according to claim 4, characterized in that the second intermediate containing phosphonate ester is processed by trimethylsilyl bromide. The step of converting the alkoxy group into a hydroxyl group to obtain the self-assembled monolayer material based on the conjugated connecting group includes: Use trimethylsilyl bromide in anhydrous dichloromethane or 1,4-dioxane to mix with the second intermediate containing phosphonate ester in an inert gas atmosphere to obtain a mixed liquid; After the mixed liquid reacts at room temperature for a third predetermined time, the self-assembled monolayer material based on the conjugated connecting group is obtained. 9. A solar cell, characterized in that, the solar cell includes a self-assembled monolayer or a hole transport layer, and the self-assembled monolayer or hole transport layer includes the method according to any one of claims 1-3. The self-assembled monolayer material based on conjugated linking groups. 10. The solar cell according to claim 9, wherein the solar cell comprises a perovskite solar cell or an organic solar cell.