Perovskite battery containing self-assembled monomolecular material and preparation method thereof

Abstract

The invention relates to a perovskite cell containing a self-assembled monomolecular material, the perovskite cell comprises a hole transport layer, a perovskite layer and an electron transport layer, the perovskite layer generates free electrons and holes in an optical excitation state, the free electrons enter the electron transport layer, the holes enter the hole transport layer, the hole transport layer contains the self-assembled monomolecular material, and the self-assembled monomolecular material contains the hole transport layer. The structural formula of the self-assembled monomolecular material is shown in the specification. In the formula, R1 is selected from-CnH2nSO3H,-CnH2nPO3H2 and-CnH2nCOOH, and n is more than or equal to 0 and less than or equal to 3; r2 is selected from-CmH2m + 1,-CmH2mSO3H,-CmH2mPO3H2 and-CmH2mCOOH, and m is larger than or equal to 0 and smaller than or equal to 5. The cell adopts thienyl SAM molecules as a hole transport material, so that the perovskite crystal grains realize preferred growth, the carrier transport efficiency is improved, and the efficiency of the perovskite cell is improved.

Description

Technical Field

[0001] This invention relates to a perovskite solar cell containing self-assembled single-molecule materials and its preparation method, belonging to the field of optoelectronics. Background Technology

[0002] Inverted perovskite solar cells (PSCs) have become a core direction of third-generation photovoltaic technology due to their low-temperature process compatibility, flexibility, and potential for integration with silicon-based cells in tandem layers. However, uncoordinated Pb at the hole transport layer (HTL) / perovskite buried interface remains a significant challenge. 2+ Halogen vacancies and hydroxyl defects can trigger severe nonradiative recombination and ion migration, limiting device efficiency and stability. Self-assembled monolayer (SAM) materials, through molecular engineering strategies, can simultaneously serve as hole transport layers while achieving interface defect passivation and energy level optimization, becoming a key technological approach to solving this problem.

[0003] Currently used traditional carbazole-based SAM materials, such as (2-(4-(methoxy)phenyl)-9H-carbazole-9-yl)ethylphosphonic acid (MeO-2PACz) and 4-(9H-carbazole-9-yl)butylphosphonic acid (4PACz), have significant structural limitations. The rigid carbazole framework of these materials cannot effectively release interfacial stress, easily leading to perovskite lattice distortion or even structural collapse. This not only directly weakens battery stability but also hinders the close packing of SAM molecules on the substrate surface, thus interfering with the preferred growth of the upper perovskite layer and causing disordered crystal orientation. Furthermore, they cannot effectively bind uncoordinated Pb at the interface. 2+ These two problems—combining halogen vacancies and halogen vacancies—directly induce a large amount of nonradiative recombination, significantly reducing the photoelectric performance of the battery, especially causing a severe open-circuit voltage (V0). OC Loss, based on perovskite solar cells made of this type of material, V OC Typically only 1.15V, this has become the core bottleneck restricting breakthroughs in device performance. Summary of the Invention

[0004] In order to solve at least one of the above problems, the present invention provides a perovskite battery containing a self-assembled single-molecule material. The battery uses thiophene-based SAM molecules as hole transport materials, enabling the perovskite grains to grow preferentially, thereby improving the carrier transport efficiency and the overall efficiency of the perovskite battery.

[0005] The technical solution adopted in this invention is as follows: a perovskite solar cell containing a self-assembled single-molecule material, comprising a hole transport layer, a perovskite layer, and an electron transport layer. The perovskite layer generates free electrons and holes under photoexcitation. Free electrons enter the electron transport layer, and holes enter the hole transport layer. The hole transport layer contains a self-assembled single-molecule material, the structural formula of which is:

[0006] ;

[0007] In the formula: R1 is selected from -C n H 2n SO3H, -C n H 2n PO3H2, -C n H 2n COOH, 0≤n≤3;

[0008] R2 is selected from —CnH 2m+1 -C m H 2m SO3H, -C m H 2m PO3H2, -C m H 2m COOH, 0≤m≤5.

[0009] Preferably, R1 is selected from —C2H5COOH, —C2H5SO3H, —C2H5PO3H2; R2 is selected from —CH3, —CH2COOH, —CH2SO3H, —CH2PO3H2.

[0010] Preferably, the perovskite material is ABX3, where A is a monovalent organic and / or inorganic cation and B is Pb. 2+ or / and Sn 2+ X is a halide ion. Further optimization yields A as a FA ion. + and / or MA + and / or Cs + At least FA is present in position A. + or MA + B is Pb 2+ X is I - and Br - The combination of [materials]. The electron transport layer material is C. 60 A hole blocking layer is provided on the side of the electron transport layer opposite to the perovskite layer. The hole blocking layer is tin oxide or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0011] Preferably, the hole transport layer is deposited on a substrate, and a metal oxide layer is deposited on the substrate, wherein the hole transport layer is deposited on the metal oxide layer.

[0012] This invention also provides a method for preparing a perovskite solar cell, comprising the following steps:

[0013] S01 Obtain a conductive substrate;

[0014] A hole transport layer is prepared by using SO2 and coating a hole transport material on the conductive side of a conductive substrate to form a hole transport layer.

[0015] The perovskite layer is prepared by S03. Perovskite material is coated on the side of the hole transport layer that is opposite to the substrate to form a perovskite layer. The perovskite layer is directly or indirectly connected to the hole transport layer.

[0016] S04. An electron transport layer is prepared by coating an electron transport material on the side of the perovskite layer opposite to the hole transport layer to form an electron transport layer, wherein the electron transport layer is directly or indirectly connected to the perovskite layer.

[0017] S05. An electrode layer is prepared on the side of the electron transport layer that is opposite to the perovskite layer. The electrode layer is directly or indirectly connected to the electron transport layer.

[0018] The hole transport layer is prepared using a solution method, in which the self-assembled monomolecule material is dissolved in an organic solvent to obtain a hole transport material solution. The concentration of the self-assembled monomolecule material in the hole transport material solution is 0.01 mM~1 mM or 0.5~1.5 mg / mL. The structural formula of the self-assembled monomolecule material is as follows:

[0019] ,

[0020] The method for preparing the self-assembled single-molecule material includes the following steps:

[0021] In a nitrogen atmosphere, dibenzothiophene and N-bromosuccinimide undergo a substitution reaction in the presence of azobisisobutyronitrile and carbon tetrachloride to give the first intermediate product, bromodibenzothiophene.

[0022] The first intermediate, SO2, undergoes a substitution reaction with carbazole under the action of a catalyst, ligand, and base to give the second intermediate, carbazole dibenzothiophene.

[0023] S03 reacts the second intermediate with iodomethane in the presence of anhydrous dichloromethane and aluminum trichloride to give the third intermediate;

[0024] S04 The third intermediate was reacted with 2-chloroethanol in the presence of anhydrous dichloromethane and aluminum trichloride via a nucleophilic substitution reaction to give the fourth intermediate, a hydroxyethyl-substituted product.

[0025] S05 The fourth intermediate is modified with functional groups to obtain the target product.

[0026] The beneficial effects of this invention include: The invention uses a material with a core framework of polycarbazole units and fluorenylthiophene as the hole transport material, improving the hole transport layer formation effect, hole transport efficiency, and battery efficiency. By combining with lead-type perovskite, it alleviates interfacial stress, improves battery stability, and directionally guides perovskite crystallization, increasing perovskite grain size and reducing defects. This hole transport material passivates the perovskite interface defect density and achieves multi-anchoring with the substrate interface, further improving carrier transport efficiency. A more detailed description of these effects will be provided in the specific implementation section. Attached Figure Description

[0027] Figure 1 FTIR images of materials 1, 2, and 3;

[0028] Figure 2 The proton NMR spectrum of Material 1;

[0029] Figure 3 The proton NMR spectrum of material 2;

[0030] Figure 4 The proton NMR spectrum of material 3;

[0031] Figure 5 Normalized voltage-current plots for Comparative Example 1 and Example 1;

[0032] Figure 6 Normalized voltage-current plots for Comparative Example 2 and Example 2;

[0033] Figure 7 Normalized voltage-current plots for Comparative Example 3 and Example 3;

[0034] Figure 8 Normalized voltage-current plots for Comparative Example 4 and Example 4;

[0035] Figure 9 SEM image of Example 4;

[0036] Figure 10 SEM image of Comparative Example 4. Detailed Implementation

[0037] The present invention is described in more detail below, but it should not be construed as limiting the scope of protection of the invention to the following description. Unless otherwise specified, any range described in the present invention includes end values, any values ​​between end values, and any sub-ranges formed by end values ​​or any values ​​between end values. There are no particular limitations on the purity of any raw materials used in the present invention; however, analytical grade materials are preferred. The sources and abbreviations of all raw materials used in the present invention are conventional sources and abbreviations in the art, and are clearly understood within the scope of their relevant uses. Those skilled in the art can obtain them from commercially available sources or prepare them using conventional methods based on the abbreviations and corresponding uses.

[0038] "At least one" means one or more, while "more" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0039] Those skilled in the art will understand that perovskite materials are represented by the general formula ABX3, wherein A is at least one monovalent cation, such as MA. + FA + Cs + 、Rb + In this case, B is at least one divalent cation, such as Ca. 2+ Pb 2+ Sn 2+ Cu 2+ Ga 2+ And X is at least one anion, such as I - ,Br - Cl - F - SCN - When a perovskite includes more than one type of A cation, the different A cations can be distributed at the A sites in an ordered or disordered manner. Similarly, when a perovskite includes more than one type of B cation, the different B cations can be distributed at the B sites in an ordered or disordered manner. Likewise, when a perovskite includes more than one type of X anion, the different X anions can be distributed at the X sites in an ordered or disordered manner.

[0040] The perovskite solar cell of this invention includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, and electrodes. The perovskite layer acts as a light-absorbing layer, generating holes and free electrons under photoexcitation, which then enter the hole transport layer and the electron transport layer, respectively. The substrate can be a rigid or flexible substrate, such as glass or resin, or it can be a solar cell that can serve as a substrate, such as a silicon solar cell. A metal oxide, such as ITO, FTO, or IZO, is disposed on at least one surface of the substrate. The hole transport layer in this invention uses a self-assembled monomolecule material with the following structural formula:

[0041] R1 and R2 are modifying groups. This self-assembled monomolecule integrates thiophene heteroatom units in the fused region of the main chain and constructs a carbazole-thiophene conjugated flexible framework using thiophene as a bridge. This not only helps release interlayer thermal stress in the hole transport layers and enhances the structural stability of the material, but also constructs efficient charge transport channels, improves perovskite grain orientation, and enhances perovskite grain growth performance. The sulfur atom at the center of the framework can strengthen interface anchoring and defect passivation, while the surrounding substituent engineering finely controls molecular stacking, which can not only improve carrier mobility and optimize energy level matching to increase V OC It can also enhance interface stability and self-assembly order, thus improving battery performance in all aspects.

[0042] In the formula: R1 is selected from -C n H 2n SO3H, -C n H 2n PO3H2, -C n H 2n COOH, 0 ≤ n ≤ 3; R2 is selected from —C m H 2m+1 -C m H 2m SO3H, -C m H 2m PO3H2, -C m H 2m COOH, 0≤m≤5. Multiple anchoring groups such as carboxylic acid, sulfonic acid, and phosphoric acid are covalently linked to the side positions of the carbazole fused ring. These groups, together with heteroatoms in the framework, achieve multi-point anchoring, strengthen the interfacial bonding between the molecule and the perovskite layer, and passivate interfacial defects to reduce non-radiative recombination. The preferred scheme is: R1 is selected from one of —C2H5COOH, —C2H5SO3H, and —C2H5PO3H2; R2 is selected from one of —CH3, —CH2COOH, —CH2SO3H, and —CH2PO3H2. Using the above materials, the Voc of the perovskite solar cell is increased to 1.95 V; at 1 cm⁻¹… 2A photoelectric conversion efficiency (PCE) of >29% was achieved on a wide bandgap device; at the same time, the stress buffering capacity of the hole transport material enabled the device to retain more than 90% of its initial efficiency after 1000 hours of continuous operation under thermal stress at 85 °C. The perovskite solar cell achieved a simultaneous improvement in efficiency and stability.

[0043] The material structure formulas that can be used for the hole transport material in this invention include:

[0044] , ,

[0045] ,

[0046] ,

[0047] ,

[0048] .

[0049] The preferred material structure is:

[0050] The π-π conjugation between the thiophene ring and the surrounding nitrogen-containing fused rings in the molecular framework promotes ordered intermolecular stacking to construct continuous and efficient charge transport channels, thereby improving carrier mobility and optimizing short-circuit current density. The sulfur atoms in the framework can interact with uncoordinated Pb atoms in the perovskite. 2+ By combining these methods, the interface anchoring effect is enhanced, and interface defects are simultaneously passivated to reduce non-radiative recombination. Materials 1, 2, and 3 can be further optimized.

[0051] Material 1 is:

[0052] The sulfur atoms in this material interact with the carboxylate groups at both ends, forming an interfacial anchoring effect that strengthens the interfacial bonding between the molecule and the perovskite layer, and passivates interfacial defects to reduce nonradiative recombination. The carboxylate groups at both ends of the molecule function as an anchoring-transporting-template: on the one hand, they form bidentate / tridentate coordination bonds with the substrate, increasing the interfacial bonding energy by more than 30% and reducing the desorption rate in polar solvents to <5%, synergistically stabilizing the interfacial structure with the sulfur atom anchoring effect of the thiophene ring; on the other hand, their electron-withdrawing effect can regulate the molecular HOMO energy level (0.2-0.4 eV), working in conjunction with the transport channels constructed by the thiophene ring to accelerate carrier transport rates and suppress grain boundary recombination.

[0053] Material 2 is:

[0054] The sulfonate groups at both ends of the material molecule act as "multifunctional interface switches": they can form bidentate / tridentate coordination bonds with the metal oxide substrate, increasing the interfacial bonding energy by more than 30%; they can also lower the molecular HOMO energy level by 0.3 eV through a strong electron-withdrawing effect, allowing the hole extraction efficiency to reach 95%; at the same time, they can further passivate defects by forming Pb-OS bonds, complementing the passivation effect of sulfur atoms in the thiophene ring, thus achieving dual suppression of interfacial defects. This also regulates the molecular packing state, ultimately improving the battery's open-circuit voltage, fill factor, and other core parameters.

[0055] Material 3 is:

[0056] The phosphate group at the end of the molecule plays a three-in-one role as "anchoring engine - energy level scissors - crystallization template", and works synergistically with the thiophene ring to achieve the following effects: on the one hand, it forms bidentate / tridentate coordination bonds with the metal oxide substrate, which increases the interfacial binding energy by more than 30%, and forms a "double anchoring" effect with the anchoring effect of the sulfur atom of the thiophene ring, which greatly enhances the interfacial stability; on the other hand, its strong electron-withdrawing effect can reduce the molecular HOMO energy level by 0.3-0.5 eV, and synergistically matches the energy level with the charge transport channel constructed by the thiophene ring, further improving the charge transport efficiency; at the same time, the phosphate group can also passivate defects by forming Pb-OP bonds, which complements the defect passivation effect of the sulfur atom, and induces the perovskite to preferentially grow along the

[001] direction, increase the grain size, and improve the crystal quality. This material strengthens interfacial stability through "sulfur atom anchoring + phosphate coordination", optimizes charge transport through "π-π conjugated channels + energy level regulation", and improves crystal quality through "dual-site defect passivation + preferential crystallization", thus achieving simultaneous optimization of interfacial stability, charge transport efficiency and perovskite crystal quality.

[0057] The perovskite layer in this invention uses perovskite material ABX3, where A is a monovalent organic and / or inorganic cation and B is Pb. 2 + or / and Sn 2+ X is a halide ion, preferably B is Pb. 2+ The aforementioned hole transport materials can effectively passivate Pb in lead-type perovskites. 2+ This reduces defect concentration and improves battery stability. Further optimization of A into FA... + and / or MA + and / or Cs + At least FA is present in position A. + or MA + B is Pb 2+ X is I - and Br -The combination of these materials allows for full utilization of the passivation effect of the hole transport material of this invention. Under the action of the hole transport material, lead and iodine vacancies in the perovskite layer are passivated, reducing the interface defect density and minimizing non-radiative recombination losses. Simultaneously, the perovskite material guides crystallization during film formation, increasing the perovskite grain size. Furthermore, in the preferred perovskite material, A is a combination of FA+, MA+, and Cs+, and B is Pb. 2+ X is I - and Br - The combination of these two materials is beneficial for achieving wide bandgap absorption and improving lattice stability. When combined with the aforementioned hole transport material, the hole transport layer provides atomic-level film formation conditions for perovskite film formation. The high energy level matching between the two materials is conducive to jointly promoting high thermal stability and high carrier transport efficiency in perovskite solar cells.

[0058] In this invention, the electron transport layer is formed by coating or vacuum evaporation, and the materials selected are fullerene derivatives, SnO2, TiO2, etc. Preferably, a hole blocking layer is provided on the side of the electron transport layer opposite to the perovskite, which is beneficial to achieve efficient extraction of charge carriers, improve the ohmic contact between the electron transport layer and the electrode layer, and prevent non-radiative recombination of charges during transport. The preferred hole blocking layer materials are tin oxide or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0059] The preparation method of the perovskite solar cell in this invention includes the following steps:

[0060] S01 Obtaining a conductive substrate: Select a rigid or flexible substrate (such as resin or glass) with a transparent conductive oxide electrode on its surface. The transparent conductive oxide electrode includes ITO, FTO, IZO, etc., and can also be a silicon solar cell.

[0061] SO2 is used to prepare a hole transport layer by depositing hole transport material on the conductive side of a conductive substrate to form the hole transport layer. The deposition method can be solution-based (spin-coating, spin-coating, etc.) or vacuum deposition. For solution-based methods, the hole transport material is dissolved in ethanol, isopropanol, or other organic solvents to prepare a solution of 0.05–4 mg / mL. After filtration, the solution is spin-coated onto a hydroxylated substrate at a spin speed of 1000–5000 r / s for 10–50 s, followed by annealing at 80–130 °C for 5–20 min to obtain the hole transport layer. The preferred solution concentration is 0.5–1.5 mg / mL.

[0062] The perovskite layer is prepared by coating a perovskite material onto the side of the hole transport layer facing away from the substrate using SO3. The perovskite layer and the hole transport layer are directly or indirectly connected. Direct connection means there are no other films between the perovskite layer and the hole transport layer; they are in direct contact. Indirect connection means there are other films between the perovskite layer and the hole transport layer, such as a modification layer or passivation layer, and the perovskite layer is connected to the hole transport layer through these other films. The perovskite layer can be prepared using one or more of the following methods: solution deposition, vapor deposition, magnetron sputtering, and atomic deposition, such as a combination of solution deposition and vapor deposition. The general formula for perovskite material is ABX3, where A is a monovalent cation, B is a divalent Pb or / and Sn ion, and X is a halide ion. If a solution deposition method is used, the preferred solvents are DMF and DMSO (volume ratio 4:1) or N-methylpyrrolidone (NMP).

[0063] S04. An electron transport layer is prepared by coating an electron transport material on the side of the perovskite layer opposite to the hole transport layer to form an electron transport layer. The electron transport layer is directly or indirectly connected to the perovskite layer. Direct connection means that the electron transport layer is in direct contact with the perovskite layer, while indirect connection means that other films, such as modification layers or passivation layers, are provided between the perovskite layer and the electron transport layer.

[0064] S05. An electrode layer is prepared on the side of the electron transport layer opposite to the perovskite layer. The electrode layer is directly or indirectly connected to the electron transport layer.

[0065] In a preferred embodiment, the fabrication method of a perovskite solar cell includes the following steps:

[0066] S01 Obtain a substrate, wherein the substrate is a silicon solar cell;

[0067] The hole transport layer is prepared by the SO2 solution method, and the material of the hole transport layer is...

[0068] ;

[0069] S03 Preparation of the perovskite layer: The perovskite layer contains perovskite material and additives, wherein the perovskite material is ABX3, and A is FA. + MA + Cs + The combination, B is Pb 2+ C is I - ,Br - The combination of the additives is MACl;

[0070] S04 Preparation of the modification layer: The modification layer material is PEAI;

[0071] S05 Preparation of the electron transport layer: The electron transport layer material is C 60 Material;

[0072] S06 Preparation of hole blocking layer: The hole blocking layer material is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline;

[0073] S07 Electrode preparation.

[0074] With the combined effect of materials and processes, the efficiency of perovskite solar cells can reach over 29%.

[0075] The following uses materials 1, 2, and 3 as examples to illustrate the synthesis method of hole transport materials. Those skilled in the art can learn the synthesis method of other hole transport materials in this invention by referring to the examples and combining them with common knowledge.

[0076] Material 1

[0077] The synthesis process is as follows:

[0078]

[0079]

[0080] The specific synthesis steps are as follows:

[0081] In a nitrogen atmosphere, dibenzothiophene and N-bromosuccinimide undergo a substitution reaction in the presence of azobisisobutyronitrile and carbon tetrachloride to give the first intermediate product, bromodibenzothiophene.

[0082] The first intermediate, SO2, undergoes a substitution reaction with carbazole under the action of a catalyst, ligand, and base to give the second intermediate, carbazole dibenzothiophene.

[0083] S03 reacts the second intermediate with iodomethane in the presence of anhydrous dichloromethane and aluminum trichloride to give the third intermediate;

[0084] S04 The third intermediate was reacted with 2-chloroethanol in the presence of anhydrous dichloromethane and aluminum trichloride via a nucleophilic substitution reaction to give the fourth intermediate, a hydroxyethyl-substituted product.

[0085] S05 The fourth intermediate was dissolved in acetone, cooled to 0 °C, and Jones' reagent (CrO3 / H2SO4 / acetone) was slowly added dropwise. The reaction was maintained at 0 °C with stirring, and then the temperature was raised to room temperature to continue the reaction. After the reaction was complete, isopropanol was added to quench the excess oxidant, and then the mixture was poured into water. After filtration, combining the organic phases, and purification, the carboxyl-modified target compound, i.e., material 1, was obtained.

[0086] Material 2;

[0087] The material synthesis process is as follows:

[0088]

[0089] .

[0090] The specific steps for material synthesis are as follows:

[0091] In a nitrogen atmosphere, dibenzothiophene and N-bromosuccinimide undergo a substitution reaction in the presence of azobisisobutyronitrile and carbon tetrachloride to give the first intermediate product, bromodibenzothiophene.

[0092] The first intermediate, SO2, undergoes a substitution reaction with carbazole under the action of a catalyst, ligand, and base to give the second intermediate, carbazole dibenzothiophene.

[0093] S03 reacts the second intermediate with iodomethane in the presence of anhydrous dichloromethane and aluminum trichloride to give the third intermediate;

[0094] S04 The third intermediate was reacted with 2-chloroethanol in the presence of anhydrous dichloromethane and aluminum trichloride via a nucleophilic substitution reaction to give the fourth intermediate, a hydroxyethyl-substituted product.

[0095] S05 The fourth intermediate was dissolved in anhydrous dichloromethane, triethylamine was added, and after cooling to 0 °C, p-toluenesulfonyl chloride was slowly added. The reaction was stirred and then brought to room temperature to continue the reaction. After the reaction was complete, the precipitate was removed by filtration, and the solvent was removed by rotary evaporation of the filtrate to obtain the p-toluenesulfonate intermediate. This intermediate was then dissolved in a water / ethanol mixture, sodium sulfite was added, and the mixture was heated to reflux. After the reaction was complete, the mixture was cooled and acidified with hydrochloric acid to pH 2-3, precipitating a solid. The crude product was collected by filtration. Finally, it was recrystallized from a dichloromethane / methanol mixture and purified to obtain the target compound, material 2.

[0096] Material 3;

[0097] The synthesis method of this material is as follows:

[0098]

[0099] .

[0100] The specific steps in the synthesis of the material include:

[0101] In a nitrogen atmosphere, dibenzothiophene and N-bromosuccinimide undergo a substitution reaction in the presence of azobisisobutyronitrile and carbon tetrachloride to give the first intermediate product, bromodibenzothiophene.

[0102] The first intermediate, SO2, undergoes a substitution reaction with carbazole under the action of a catalyst, ligand, and base to give the second intermediate, carbazole dibenzothiophene.

[0103] S03 reacts the second intermediate with iodomethane in the presence of anhydrous dichloromethane and aluminum trichloride to give the third intermediate;

[0104] S04 The third intermediate was reacted with 2-chloroethanol in the presence of anhydrous dichloromethane and aluminum trichloride via a nucleophilic substitution reaction to give the fourth intermediate, a hydroxyethyl-substituted product.

[0105] S05 The fourth intermediate was dissolved in anhydrous dichloromethane, phosphorus trichloride was added, and the mixture was stirred at room temperature. Water was then slowly added, and the mixture was heated under reflux to hydrolyze and generate phosphonic acid. After the reaction was complete, the mixture was cooled, the pH was adjusted to neutral with sodium bicarbonate solution, and the mixture was extracted with dichloromethane. The combined organic phases yielded a crude phosphonic acid-substituted product. After purification, the target compound modified with phosphonic acid, material 3, was obtained.

[0106] The following examples further illustrate this point.

[0107] Example 1

[0108] This embodiment fabricates an inverted perovskite solar cell device. The fabrication method includes the following steps:

[0109] S01 Substrate Pretreatment

[0110] A 100 mm × 100 mm ITO conductive glass substrate was selected and laser-cut to the required size. It was then sequentially immersed in a detergent solution, deionized water, anhydrous ethanol, and isopropanol, undergoing ultrasonic cleaning for 10 minutes in each solution to thoroughly remove surface oil and impurities. After cleaning, the substrate was immersed in isopropanol and sealed for later use. Before use, the surface was rapidly purged with a high-pressure nitrogen gun to remove residual isopropanol droplets, followed by a 20-minute surface hydroxylation treatment in a UV-ozone cleaner to improve the substrate's hydrophilicity and adhesion.

[0111] Preparation of S02 hole transport layer by scraping

[0112] (1) Preparation of precursor solution: Weigh 1 mg of material 1 and dissolve it in 1 mL of anhydrous ethanol. Place it on a magnetic stirrer and stir for 12 h to prepare a homogeneous solution with a concentration of 1 mg / mL. Before use, filter it with a 0.22 μm organic phase needle filter to remove undissolved particulate impurities and avoid film defects during coating.

[0113] (2) Film formation by blade coating: The cavity transport layer is coated using an automatic blade coating machine. The blade height is set to 150 μm and the coating speed is 8 mm / s. The precursor solution is evenly spread on the surface of the pretreated ITO substrate. The ambient humidity is kept ≤30% during the coating process.

[0114] (3) Annealing and curing: The coated sample is immediately transferred to the heating table and annealed at 100 °C for 10 min to complete the curing of the hole transport layer. After natural cooling to room temperature, it is ready for use.

[0115] Preparation of large-area coating of S03 perovskite layer

[0116] (1) Preparation of precursor solution: Accurately weigh formamidinium hydroiodate (FAI), lead iodide (PbI2) and lead bromide (PbBr2) in a molar ratio of 1:0.75:0.25, add them to a mixed solvent of N,N-dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 4:1), and stir magnetically for 12 h until completely dissolved to prepare a perovskite precursor solution with a concentration of 1.6 mol / L; then use a 0.22 μm filter membrane for vacuum filtration to remove trace amounts of insoluble impurities in the solution, and store the filtered solution in a glove box protected from light.

[0117] (2) Film formation by scraping: The perovskite layer is scraped in an inert gas glove box. The scraper height is set to 200 μm and the scraping speed is 6 mm / s to ensure that the precursor solution uniformly covers the surface of the hole transport layer. After the scraping is completed, a small amount of ethyl acetate vapor is immediately introduced into the glove box to induce the perovskite precursor to initially crystallize and form a uniform wet film.

[0118] (3) Annealing and crystallization: Transfer the wet film sample to the heating stage in the glove box, preheat it at 60 ℃ for 5 min to slowly remove some of the solvent, and then heat it to 100 ℃ for annealing for 30 min to complete the full growth and crystallization of the perovskite crystal. After naturally cooling to room temperature, a dense and uniform perovskite active layer is obtained.

[0119] Fabrication of the S04 electron transport layer

[0120] C was deposited on the surface of the perovskite active layer using a vacuum thermal evaporation method. 60 Electron transport layer: Place the sample into the vacuum deposition chamber and start the vacuum pump to evacuate to 4 × 10⁻⁶. -4 Below Pa, C is evaporated by resistance heating. 60 The material was used, with an evaporation rate of 0.1 nm / s and a deposition thickness of 20 nm. The sample temperature was kept at room temperature during the deposition process.

[0121] Preparation of S05 Hole Blocking Layer

[0122] Atomic layer deposition (ALD) technology was used in C 60 A tin oxide (SnO2) hole-blocking layer was prepared on the surface of the electron transport layer: the deposition temperature was set at 80 °C, tin tetrachloride and deionized water were used as precursors, and the SnO2 layer thickness was precisely controlled to 20 nm through 70 deposition cycles to ensure that the film was free of pinholes and had uniform coverage.

[0123] Preparation of S06 transparent conductive layer

[0124] Indium tin oxide (ITO) transparent conductive layer was deposited on the surface of the SnO2 hole-blocking layer using magnetron sputtering: the vacuum level in the sputtering chamber was evacuated to 4 × 10⁻⁶. -3 Below Pa, a mixture of argon and oxygen (volume ratio 9:1) is introduced, and the sputtering power is set to 100W, the substrate temperature to 150℃, and the deposition thickness to 20 nm, ensuring that the transmittance of the conductive layer is ≥85%.

[0125] Preparation of S07 top electrode

[0126] Electrode deposition: A silver (Ag) top electrode is deposited on the surface of the transparent conductive layer using a vacuum thermal deposition method, with the vacuum level in the deposition chamber maintained at 5 × 10⁻⁶. -4 Below Pa, the evaporation rate is controlled at 0.5 nm / s, and the deposition thickness is 100 nm. After evaporation, the electrode edges are trimmed by laser cutting to remove excess film.

[0127] Perovskite solar cells were fabricated.

[0128] Material 1 used in the hole transport layer is synthesized by the following method:

[0129] S01 First, 1.0 mmol of dibenzothiophene (DBT), 4.0 mmol of N-bromosuccinimide (NBS), and a catalytic amount of azobisisobutyronitrile (AIBN) were sequentially added to a three-necked flask. Then, approximately 13 mL of dried carbon tetrachloride (CCl4) was added, followed by purging the system with nitrogen to purge air. The reaction apparatus was then placed under light and heated to reflux, with the consumption of reactants monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the generated succinimide was removed by filtration. The filtrate was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the product was purified by column chromatography (eluent: petroleum ether) to obtain the first intermediate: 2,3,7,8-tetrabromodibenzothiophene.

[0130] S02: Subsequently, 1.0 mmol of 2,3,7,8-tetrabromodibenzothiophene, 4.0 mmol of carbazole, 0.05 mmol of palladium catalyst (Pd2(dba)3), 0.1 mmol of ligand (BrettPhos), and 5.0 mmol of base (NaOtBu) were added sequentially to a three-necked flask, followed by 13 mL of anhydrous toluene. Nitrogen gas was then purged into the system to purge air. The reaction mixture was then heated to reflux, and the reaction progress was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature and extracted three times with 50 mL of ethyl acetate each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 5:1) to give the second intermediate: tetracarbazolyldibenzothiophene.

[0131] S03: Next, 1.0 mmol of tetracarbazolyldibenzothiophene was dissolved in approximately 10 mL of anhydrous dichloromethane (DCM), and 3.0 mmol of aluminum trichloride (AlCl3) was added. After stirring until homogeneous, 2.2 mmol of iodomethane (CH3I) was slowly added dropwise. The reaction was stirred at room temperature, and the reaction progress was monitored by TLC. After the reaction was complete, the reaction solution was slowly poured into ice water to quench it. The solution was extracted three times with dichloromethane, 30 mL each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the solution was purified by column chromatography (eluent: petroleum ether / dichloromethane = 3:1) to obtain the third intermediate: dimethyl-tetracarbazolyldibenzothiophene, which was used for the subsequent introduction of sulfonic acid side chains.

[0132] S04: Dissolve 1.0 mmol of dimethyl-tetracarbazolyldibenzothiophene in approximately 10 mL of anhydrous dichloromethane, add 3.0 mmol of aluminum trichloride (AlCl3), and add 2.2 mmol of 2-chloroethanol (ClCH2CH2OH) while stirring. The reaction mixture was stirred at room temperature for 8 hours. After the reaction was complete as monitored by TLC, the reaction solution was poured into ice water and extracted three times with dichloromethane, 30 mL each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the fourth intermediate: the hydroxyethyl-substituted product.

[0133] S05: Finally, the hydroxyethyl-substituted product was dissolved in 8 mL of acetone, cooled to 0 °C, and then 2.2 mmol equivalent Jones reagent (CrO3 / H2SO4 / acetone) was slowly added dropwise. The reaction was maintained at 0 °C with stirring for 2 hours, then raised to room temperature and continued for another 4 hours. After the reaction was complete, isopropanol was added to quench excess oxidant, followed by extraction with water. The mixture was extracted three times with 30 mL of ethyl acetate each time. The combined organic phases were dried over anhydrous sodium sulfate and the solvent was removed by rotary evaporation to obtain the carboxyl-substituted crude product. Finally, it was recrystallized from a dichloromethane / methanol mixture and purified by column chromatography (eluent: dichloromethane / methanol = 15:1) to obtain the carboxyl-modified target product, material 1. The molecular structure of the target product was analyzed, and the results are as follows: Figure 1 and Figure 2 As shown, the structural formula of the synthesized target product is:

[0134] That is, material 1.

[0135] Example 2

[0136] This embodiment aims to fabricate a pin-configuration normal bandgap perovskite solar cell device. The specific fabrication process is as follows:

[0137] S01 Substrate Pretreatment

[0138] ITO conductive glass with a specification of 100 mm × 100 mm was selected, laser-cut, and then ultrasonically cleaned by sequentially immersing it in detergent solution, deionized water, anhydrous ethanol, and isopropanol. After cleaning, the ITO glass was immersed in isopropanol and sealed for storage. Before use, residual isopropanol on the surface was quickly removed by blowing with a nitrogen gun, and then the substrate surface was activated by a plasma surface cleaner.

[0139] Preparation of S02 hole transport layer

[0140] (1) Dissolve material 2 in a mixed solvent of isopropanol and chlorobenzene to prepare a hole transport layer precursor solution with a concentration of 0.5 mg / mL. Before use, filter the solution through a 0.22 μm organic phase filter to remove incompletely dissolved particulate impurities.

[0141] (2) The precursor solution was coated using a slit coating method. The coating parameters were set as follows: coating rate 8 mm / s, injection rate 2.5 μL / s; an N2 air knife was placed behind the coating doctor blade to assist in film formation, with a distance of 4 mm between the air knife and the coating surface, an inclination angle of 40°, and a gas supply pressure of 0.08 MPa. After coating, the sample was placed on a 120 ℃ heating table for annealing for 10 min.

[0142] Preparation of S03 perovskite active layer

[0143] (1) Weigh formamidin hydroiodide (FAI) and lead iodide (PbI2) in a molar ratio of 1:1 and add them to a mixed solvent of N,N-dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 3:1). After stirring and shaking with magnetic force for 12 h, a perovskite precursor solution with a concentration of 1 mol / L is prepared. Then, filter the solution with a 0.22 μm filter membrane to remove large particles that are not completely dissolved.

[0144] (2) The perovskite precursor solution was coated using a slit coating process with a coating rate of 12 mm / s and a liquid injection rate of 4.0 μL / s. Simultaneously, an N2 air knife was used to assist in film formation with a distance of 6 mm between the air knife and the coating surface, a cutting angle of 50°, and an air pressure of 0.12 MPa.

[0145] (3) After coating, transfer the sample to a vacuum drying device and dry it at 1×10⁻⁶. -1 The film was held under vacuum for 30 seconds to completely remove any residual organic solvents.

[0146] (4) The sample was then placed in an ethanol atmosphere and annealed at 100 °C for 30 min to complete the crystallization of the perovskite active layer.

[0147] Preparation of S04 electron transport layer

[0148] C was deposited on the surface of the perovskite active layer using a vacuum thermal evaporation method. 60 Electron transport layer: The sample is placed in a vacuum evaporation chamber, and the chamber vacuum level is reduced to 5 × 10⁻⁶. -4 After Pa, C is deposited by thermal evaporation. 60 The material was used to control the film thickness to 20 nm.

[0149] Preparation of S05 Hole Blocking Layer

[0150] Atomic layer deposition (ALD) technology was used in C 60 A tin oxide (SnO2) hole-blocking layer was deposited on the surface of the electron transport layer. The deposition cycle number was set to 55 cycles, and the SnO2 layer thickness was controlled to be 10 nm. After deposition, the sample was laser-cut and the residual film at the edges was cleaned.

[0151] Fabrication of S06 top electrode

[0152] A vacuum thermal evaporation process was used to deposit silver (Ag) as the top electrode on the surface of the SnO2 hole-blocking layer, while maintaining the vacuum level of the evaporation chamber at 4 × 10⁻⁶. -4Below Pa, the Ag electrode thickness was controlled to be 80 nm. After electrode deposition, final laser cutting and edge fine cleaning were performed to obtain a complete inverted normal bandgap perovskite solar cell device.

[0153] The preparation method of material 2 in the hole transport material is as follows:

[0154] S01 First, 1.0 mmol of dibenzothiophene (DBT), 4.0 mmol of N-bromosuccinimide (NBS), and a catalytic amount of azobisisobutyronitrile (AIBN) were sequentially added to a three-necked flask, followed by 13 mL of dried carbon tetrachloride (CCl4). Nitrogen gas was then introduced into the system to purge air. The reaction apparatus was then placed under light and heated to reflux, with the consumption of reactants monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the generated succinimide was removed by filtration. The filtrate was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the mixture was purified by column chromatography (eluent: petroleum ether) to obtain the first intermediate: 2,3,7,8-tetrabromodibenzothiophene, which provides an intermediate for subsequent coupling reactions.

[0155] S02: Subsequently, 1.0 mmol of 2,3,7,8-tetrabromodibenzothiophene, 4.0 mmol of carbazole, 0.05 mmol of palladium catalyst (Pd2(dba)3), 0.1 mmol of ligand (BrettPhos), and 5.0 mmol of base (NaOtBu) were added sequentially to a three-necked flask, followed by the addition of 13 mL of anhydrous toluene. Nitrogen gas was then purged into the system to purge air. The reaction mixture was then heated to reflux, with the reaction progress monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted three times with 50 mL of ethyl acetate each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the mixture was purified by column chromatography (eluent: petroleum ether / dichloromethane = 5:1) to obtain the second intermediate: tetracarbazolyldibenzothiophene, which is prepared for subsequent methylation modification.

[0156] S03: Next, 1.0 mmol of tetracarbazolyldibenzothiophene was dissolved in approximately 10 mL of anhydrous dichloromethane (DCM), and 3.0 mmol of aluminum trichloride (AlCl3) was added. After stirring until homogeneous, 2.2 mmol of iodomethane (CH3I) was slowly added dropwise. The reaction was stirred at room temperature, and the reaction progress was monitored by TLC. After the reaction was complete, the reaction solution was slowly poured into ice water to quench it. The solution was extracted three times with dichloromethane, 30 mL each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the solution was purified by column chromatography (eluent: petroleum ether / dichloromethane = 3:1) to obtain the third intermediate: dimethyl-tetracarbazolyldibenzothiophene, which was used for the subsequent introduction of sulfonic acid side chains.

[0157] S04: Dissolve 1.0 mmol of dimethyl-tetracarbazolyldibenzothiophene in approximately 10 mL of anhydrous dichloromethane, add 3.0 mmol of aluminum trichloride (AlCl3), and add 2.2 mmol of 2-chloroethanol (ClCH2CH2OH) while stirring. The reaction mixture was stirred at room temperature for 8 hours. After the reaction was complete as monitored by TLC, the reaction solution was poured into ice water and extracted three times with dichloromethane (30 mL each time). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the fourth intermediate: the hydroxyethyl-substituted product.

[0158] S05: Finally, the hydroxyethyl-substituted product was dissolved in approximately 8 mL of anhydrous dichloromethane, and 3.0 mmol of triethylamine (Et3N) was added. After cooling to 0°C, 2.2 mmol of p-toluenesulfonyl chloride (TsCl) was slowly added. The mixture was stirred for 2 hours, then the reaction was continued at room temperature for another 4 hours. After the reaction was complete, the precipitate was removed by filtration, and the solvent was removed by rotary evaporation of the filtrate to obtain the p-toluenesulfonate intermediate. This intermediate was then dissolved in approximately 10 mL of a water / ethanol mixture (volume ratio 1:1), and 3.0 mmol of sodium sulfite (Na2SO3) was added. The mixture was heated under reflux for 8 hours. After the reaction was complete, the mixture was cooled, acidified with hydrochloric acid to pH 2-3, and a solid precipitated. The crude product was collected by filtration. Finally, it was recrystallized from a dichloromethane / methanol mixture and purified by column chromatography (eluent: dichloromethane / methanol = 20:1) to obtain the sulfonic acid-modified target product, material 2. The molecular structure of the target product was then determined, as shown in the figure. Figure 1 and Figure 3 As shown, the structural formula of the synthesized target product is:

[0159] That is, material 2.

[0160] Example 3

[0161] In this embodiment, perovskite / silicon tandem solar cells are fabricated using material 3, with the perovskite material selected being 1.7 MFA. 0.85 MA 0.10 Cs 0.05 Pb(I 0.75 Br 0.25 3. The specific preparation steps are as follows:

[0162] S01 Substrate Pretreatment

[0163] A 2.5 cm × 2.5 cm heterojunction silicon wafer was selected as the substrate for the tandem solar cell. The substrate was placed face up in an ultraviolet ozone environment for 15 min for treatment and then set aside.

[0164] Preparation of S02 Hole Transport Layer (HTL)

[0165] (1) Solution preparation: Dissolve 0.5 mg of material 3 in 1 mL of chlorobenzene / isopropanol mixed solution (volume ratio 1:3) to prepare a material solution of 0.5 mg / mL; filter through a 0.22 μm filter membrane to remove impurities and set aside for use.

[0166] (2) Spin coating: The filtered solution is spin coated onto the surface of ITO glass. The spin coating parameters are set to 4000 rpm and 40 s.

[0167] (3) Annealing treatment: Anneal at 100 °C for 10 min to form a hole transport layer with a thickness of about 22 nm.

[0168] S03 for preparing perovskite layers

[0169] (1) Preparation of perovskite solution

[0170] a. Preparation of mother liquor: 548.59 mg PbI₂, 25.31 mg MABr, 22.1 mg CsI, 238.56 mg FAI, and 187.17 mg PbBr₂ were dissolved in a mixed solvent of 0.80 mL N,N-dimethylformamide (DMF) and 0.2 mL dimethyl sulfoxide (DMSO); the solution was stirred at room temperature for more than 4 h until completely dissolved, and then filtered through a 0.22 μm organic filter membrane to obtain 1.7 MFA. 0.85 MA 0.10 Cs 0.05 Pb(I 0.75 Br 0.25 3. Perovskite mother liquor.

[0171] b. Additive doping: Add MACl additive to the above mother liquor to prepare a perovskite precursor solution with a MACl mass fraction of 20% (solution two).

[0172] c. Heating to dissolve: Heat solution 2 to 70 °C and stir for 70 min until completely dissolved.

[0173] d. Filtration and impurity removal: Large particulate impurities in the solution are removed by filtration through a 0.22 μm filter membrane to obtain a spin-coated perovskite layer solution.

[0174] (2) Spin coating and antisolvent treatment: Spin coat the perovskite layer solution onto the surface of the hole transport layer at a spin coating rate of 4000 rpm; when spin coating reaches 10 s, quickly drop 0.2 mL of antisolvent chlorobenzene onto the film surface (dropping is completed within 2 s), and continue spin coating until the total time is 40 s.

[0175] (3) Annealing to form a film: After spin coating, anneal in an air atmosphere of 100 °C and 20~30% humidity for 20 min to form a perovskite layer with a thickness of about 700 nm.

[0176] S04 Preparation of Modification Layer

[0177] (1) Preparation of modified solution: Dissolve 0.5 mg phenylethyl iodide (PEAI) in 1 mL isopropanol and shake and stir until completely dissolved; filter through a 0.22 μm filter membrane to remove impurities and obtain a 0.5 mg / mL PEAI isopropanol solution.

[0178] (2) Spin coating and annealing: The PEAI solution was spin coated onto the surface of the perovskite layer with spin coating parameters of 2000 rpm and 30 s; then annealed at 100 ℃ for 30 s in a glove box to form a PEAI modified layer with a thickness of about 3 nm.

[0179] S05 Preparation of Electron Transport Layer

[0180] C was deposited on the surface of the modification layer using a vacuum thermal evaporation method. 60 The material was used to form an electron transport layer with a thickness of 20 nm, and the evaporation vacuum was controlled at 5 × 10⁻⁻⁻⁶. 4 Below Pa.

[0181] S06 Hole Blocking Layer Preparation

[0182] A hole-blocking layer with a thickness of 8 nm was prepared by depositing BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) material on the surface of the electron transport layer using a vacuum thermal evaporation process, with a evaporation vacuum degree ≤4×10⁻. 4 Pa.

[0183] S07 Electrode Preparation

[0184] A 150 nm thick silver (Ag) electrode was deposited on the surface of the hole blocking layer (BCP) using a vacuum thermal evaporation method, while maintaining a evaporation vacuum of 7 × 10⁻⁻⁻⁶. 4 Below Pa.

[0185] Perovskite solar cells were fabricated.

[0186] The synthesis method of material 3 in the hole transport layer is as follows:

[0187] S01: First, 1.0 mmol of dibenzothiophene (DBT), 4.0 mmol of N-bromosuccinimide (NBS), and a catalytic amount of azobisisobutyronitrile (AIBN) were sequentially added to a three-necked flask, followed by 13 mL of dried carbon tetrachloride (CCl4). Nitrogen gas was then introduced to purge the air. The reaction apparatus was then placed under light and heated to reflux. The consumption of reactants was monitored by TLC, and the reaction typically lasted for several hours. After the reaction was complete, the mixture was cooled to room temperature, and the generated succinimide solid was removed by filtration. The filtrate was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, using petroleum ether as the eluent, the first intermediate, 2,3,7,8-tetrabromodibenzothiophene, was obtained by column chromatography and used as an intermediate for subsequent coupling reactions.

[0188] S02: Subsequently, 1.0 mmol of 2,3,7,8-tetrabromodibenzothiophene, 4.0 mmol of carbazole, 0.05 mmol of palladium catalyst (Pd2(dba)3), 0.1 mmol of ligand (BrettPhos), and 5.0 mmol of base (NaOtBu) were added sequentially to a three-necked flask, followed by the addition of 13 mL of anhydrous toluene. Nitrogen gas was then introduced to purge air from the system. The reaction mixture was then heated to reflux, with the reaction progress monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted three times with 50 mL of ethyl acetate each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the mixture was purified by column chromatography (eluent: petroleum ether / dichloromethane = 5:1) to obtain the second intermediate: tetracarbazolyldibenzothiophene, which is used for subsequent methylation modification.

[0189] S03: Next, 1.0 mmol of tetracarbazolyldibenzothiophene was dissolved in 10 mL of anhydrous dichloromethane (DCM), and 3.0 mmol of aluminum trichloride (AlCl3) was added. After stirring until homogeneous, 2.2 mmol of iodomethane (CH3I) was slowly added dropwise. The reaction was stirred at room temperature, and the reaction progress was monitored by TLC. After the reaction was complete, the reaction solution was slowly poured into ice water to quench it. The solution was extracted three times with dichloromethane, 30 mL each time. The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Finally, the solution was purified by column chromatography (eluent: petroleum ether / dichloromethane = 3:1) to obtain the third intermediate: dimethyl-tetracarbazolyldibenzothiophene, which was used for the subsequent introduction of sulfonic acid side chains.

[0190] S04: Dissolve 1.0 mmol of dimethyl-tetracarbazolyldibenzothiophene in 10 mL of anhydrous dichloromethane, add 3.0 mmol of aluminum trichloride (AlCl3), and add 2.2 mmol of 2-chloroethanol (ClCH2CH2OH) while stirring. Stir the reaction at room temperature for 8 hours. After the reaction is complete as monitored by TLC, pour the reaction solution into ice water and extract three times with dichloromethane, 30 mL each time. Combine the organic phases, dry them over anhydrous sodium sulfate, and remove the solvent by rotary evaporation to obtain the fourth intermediate: the hydroxyethyl-substituted product.

[0191] S05: Finally, 8 mL of the hydroxyethyl-substituted product was dissolved in anhydrous dichloromethane, and 2.2 mmol of phosphorus trichloride (PCl3) was added. After stirring at room temperature for 4 hours, 5 mL of water was slowly added and the mixture was heated under reflux for 6 hours to hydrolyze and generate phosphonic acid. After the reaction was completed, the mixture was cooled, and the pH was adjusted to neutral with sodium bicarbonate solution. The mixture was extracted three times with 30 mL of dichloromethane each time. The combined organic phases were dried over anhydrous sodium sulfate and the solvent was removed by rotary evaporation to obtain the crude phosphonic acid-substituted product. Finally, the product was recrystallized from a dichloromethane / methanol mixed solvent and purified by column chromatography (eluent: dichloromethane / methanol = 15:1) to obtain the phosphonic acid-modified target product, material 3. The molecular structure of the target product was analyzed, such as... Figure 1 and Figure 4 As shown, the structural formula of the synthesized product is:

[0192] That is, material 3.

[0193] Example 4

[0194] This embodiment fabricates an inverted wide-bandgap perovskite solar cell device. The fabrication method includes the following steps:

[0195] S01 Obtain the substrate

[0196] ITO glass was selected and ultrasonically treated sequentially with deionized water for 15 min, ethanol, acetone, isopropanol, and ethanol for 30 min each, dried with nitrogen, and then treated with ultraviolet-ozone for 30 min.

[0197] S02 is used to prepare the hole transport layer.

[0198] (1) Dissolve 1 mg of material 1 in 1 mL of ethanol and shake for 15 h to obtain a solution of 1 mg / mL. Filter the undissolved large particles using a 0.22 μm needle filter for later use. The preparation method of material 1 is the same as in Example 1.

[0199] (2) The solution was spin-coated onto the glass substrate using a spin-coating method with an acceleration of 500 r / s. 2 Speed ​​4000 r / s, time 30 s.

[0200] (3) An annealing scheme was adopted, and the annealing was carried out at 120 °C for 10 min.

[0201] Preparation of S03 perovskite layer

[0202] (1) Formamidinium hydroiodide (FAI), lead iodide (PbI2), and lead bromide (PbBr2) were mixed in a molar ratio of 1:0.65:0.35, and then dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 to prepare a perovskite precursor solution with a concentration of 1.4 mol / L. The above solution was filtered through a filter membrane with a pore size of 0.22 μm to obtain the precursor solution.

[0203] (2) Spin coating was performed on the surface of the SAM layer at a speed of 5000 r / s for a total spin coating time of 40 s. At the 15th second before the end of the spin coating process, the anti-solvent chlorobenzene was added to the system to finally obtain a perovskite wet film.

[0204] (3) The obtained perovskite wet film was transferred to a nitrogen atmosphere and annealed at 100 °C for 20 min. After cooling, a perovskite layer was formed.

[0205] S04 is used to prepare the electron transport layer.

[0206] Vacuum evaporation equipment is used to apply C through a thermal evaporation process. 60 Material evaporation; an electron transport layer with a thickness of 20 nm is deposited on the surface of the prepared perovskite layer. During the evaporation process, the vacuum level in the evaporation chamber needs to be controlled at 5 × 10⁻⁶. -4 Below Pa.

[0207] Preparation of S05 Hole Blocking Layer

[0208] A SnO2 hole-blocking layer with a thickness of 20 nm was prepared using an atomic layer deposition (ALD) apparatus.

[0209] Preparation of S06 electrode:

[0210] A vacuum evaporation deposition system was used to deposit silver (Ag) electrodes onto the BCP layer surface via thermal evaporation. The electrode thickness was controlled to be 100 nm, and the vacuum level of the deposition chamber was maintained at 4 × 10⁻⁶ during the deposition process. -4 Below Pa.

[0211] Perovskite solar cells were fabricated.

[0212] Comparative Example 1

[0213] The only difference from Example 1 is the choice of different hole transport materials. Comparative Example 1 uses MeO-2PACz as the hole transport material, and the other steps and conditions are the same as those in Example 1. The photoelectric conversion efficiency of the perovskite solar cells in Example 1 and Comparative Example 1 was tested. The test process adopted a scanning mode from high voltage (1.5 V) to low voltage (-0.2 V), with a scan step size of 0.02 V and an interval of 20 ms between adjacent scan points. When calculating the cell conversion efficiency, the conversion power of the cell was first obtained by multiplying the voltage and current, and then combined with the incident power of sunlight to finally obtain the photoelectric conversion efficiency of the cell. The results are shown in Table 1 and... Figure 1 As shown. From Figure 5 As can be seen from the test data in Table 1, Example 1 showed significant improvements in parameters such as Voc, fill factor, and efficiency of the battery compared to Comparative Example 1.

[0214] Comparative Example 2

[0215] The only difference between Comparative Example 2 and Example 2 is the hole transport material. Comparative Example 2 uses 2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinylphosphonic acid (MPA-CPA) as the hole transport material. The other steps and conditions are the same as those in Example 2.

[0216] The photoelectric conversion efficiency of the perovskite solar cells in Example 2 and Comparative Example 2 was tested. The test process employed a scanning mode from high voltage (1.5 V) to low voltage (-0.2 V), with a scan step size of 0.02 V and an interval of 20 ms between adjacent scan points. To calculate the cell conversion efficiency, the conversion power was first obtained by multiplying the voltage and current, and then combined with the incident sunlight power to finally determine the photoelectric conversion efficiency. The results are shown in Table 1 and [Table data missing]. Figure 6 As shown, compared with Comparative Example 2, the open-circuit voltage, fill factor, efficiency and other core parameters of the battery in Example 2 are significantly improved.

[0217] Comparative Example 3

[0218] The difference from Example 3 lies in the choice of different hole transport materials. In Comparative Example 3, the hole transport material is 2,3,5,6-tetra(9H-carbazole-3-yl)thiophene[3,2-b:4,5-b']dibenzothiophene, and the structural formula of the material is:

[0219] Other steps and conditions are the same as those in the example.

[0220] The photoelectric conversion efficiency of the perovskite solar cells in Example 3 and Comparative Example 3 was tested. The test process employed a scanning mode from high voltage (1.5 V) to low voltage (-0.2 V), with a scan step size of 0.02 V and an interval of 20 ms between adjacent scan points. To calculate the cell conversion efficiency, the conversion power was first obtained by multiplying the voltage and current, and then combined with the incident power of sunlight to finally determine the photoelectric conversion efficiency. (See Table 1 and...) Figure 7 It can be seen that, compared with Comparative Example 3, the core parameters of the battery in Example 3, such as open-circuit voltage, fill factor, and efficiency, are significantly improved.

[0221] Comparative Example 4

[0222] The only difference from Example 4 is the hole transport material. In this comparative example, the hole transport material is 2,3,5,6-tetra(9H-carbazole-3-yl)thiophene[3,2-b:4,5-b']dibenzothiophene. The other steps and conditions are the same as those in the example.

[0223] The photoelectric conversion efficiency of the perovskite solar cells in Example 4 and Comparative Example 4 was tested. The test process employed a scanning mode from high voltage (1.5 V) to low voltage (-0.2 V), with a scan step size of 0.02 V and an interval of 20 ms between adjacent scan points. To calculate the cell conversion efficiency, the conversion power was first obtained by multiplying the voltage and current, and then combined with the incident power of sunlight to finally determine the photoelectric conversion efficiency. (See Table 1 and...) Figure 8 It can be seen that the open-circuit voltage, fill factor, efficiency, and other core parameters of the cell in Example 4 are significantly improved compared to Comparative Example 4. Observing the SEM images of the perovskite films obtained in Example 4 and Comparative Example 4, it can be seen that Example 4 has a larger grain size, more uniform film formation, and higher crystal quality compared to Comparative Example 4.

[0224] Table 1 Performance parameters of perovskite solar cells in each comparative example and embodiment

[0225] Voc (V) <![CDATA[Jsc (mA / cm 2 )]]> FF (%) PCE (%) Comparative Example 1 1.09 23.32 76.23 19.38 Example 1 1.18 23.87 80.65 22.72 Comparative Example 2 1.14 22.95 77.37 20.24 Example 2 1.19 23.37 80.45 22.37 Comparative Example 3 1.85 19.51 79.30 28.62 Example 3 1.95 19.68 81.70 31.35 Comparative Example 4 1.15 21.80 82.56 20.70 Example 4 1.24 22.24 84.98 23.44

[0226] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A perovskite battery containing a self-assembled single-molecule material, characterized in that: It includes a hole transport layer, a perovskite layer, and an electron transport layer. The perovskite layer generates free electrons and holes under photoexcitation. Free electrons enter the electron transport layer, and holes enter the hole transport layer. The hole transport layer contains a self-assembled monomolecule material, the structural formula of which is: ； In the formula: R1 is selected from -C n H 2n SO3H, -C n H 2n PO3H2, -C n H 2n COOH, 0≤n≤3; R2 is selected from —C m H 2m+1 -C m H 2m SO3H, -C m H 2m PO3H2, -C m H 2m COOH, 0≤m≤5.

2. The perovskite battery containing self-assembled single-molecule materials according to claim 1, characterized in that: R1 is selected from —C2H5COOH, —C2H5SO3H, —C2H5PO3H2; R2 is selected from —CH3, —CH2COOH, —CH2SO3H, —CH2PO3H2.

3. The perovskite battery containing self-assembled single-molecule materials according to claim 1, characterized in that: The structural formula of the self-assembled monomolecule material is: ， ， ， ， ， ， ， ， ， ， ， 。 4. The perovskite battery containing self-assembled single-molecule materials according to claim 1, characterized in that: The perovskite material is ABX3, where A is a monovalent organic and / or inorganic cation and B is Pb. 2+ or / and Sn 2+ X represents a halide ion.

5. The perovskite battery containing self-assembled single-molecule materials according to claim 4, characterized in that: A is FA + and / or MA + and / or Cs + At least FA is present in position A. + or MA + B is Pb 2+ X is I - and Br - The combination of .

6. The perovskite battery containing self-assembled single-molecule materials according to claim 1, characterized in that: The electron transport layer material is C. 60 A hole blocking layer is provided on the side of the electron transport layer opposite to the perovskite layer. The hole blocking layer is tin oxide or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

7. The perovskite battery containing self-assembled single-molecule materials according to claim 1, characterized in that: The hole transport layer is deposited on a substrate, on which a metal oxide layer is deposited, and the hole transport layer is deposited on the metal oxide layer.

8. A method for preparing a perovskite solar cell according to claim 1, characterized in that: Includes the following steps S01 Obtain a substrate, wherein a metal oxide layer is deposited on at least one side of the substrate; SO2 is used to prepare a hole transport layer by depositing a hole transport material on the metal oxide layer side of a conductive substrate to form a hole transport layer. S03 is used to prepare a perovskite layer by depositing perovskite material on the side of the hole transport layer that is opposite to the substrate to form a perovskite layer. The perovskite layer is directly or indirectly connected to the hole transport layer. S04. An electron transport layer is prepared by depositing an electron transport material on the side of the perovskite layer opposite to the hole transport layer to form an electron transport layer, wherein the electron transport layer is directly or indirectly connected to the perovskite layer. S05. An electrode layer is prepared on the side of the electron transport layer that is opposite to the perovskite layer. The electrode layer is directly or indirectly connected to the electron transport layer. The hole transport layer is prepared by a solution method, in which the self-assembled monomolecule material is dissolved in an organic solvent to obtain a hole transport material solution, wherein the concentration of the self-assembled monomolecule material in the hole transport material solution is 0.5~1.5 mg / mL.

9. The preparation method according to claim 8, characterized in that: The structural formula of the self-assembled monomolecule material is: ， The method for preparing the self-assembled single-molecule material includes the following steps: In a nitrogen atmosphere, dibenzothiophene and N-bromosuccinimide undergo a substitution reaction in the presence of azobisisobutyronitrile and carbon tetrachloride to give the first intermediate product, bromodibenzothiophene. The first intermediate, SO2, undergoes a substitution reaction with carbazole under the action of a catalyst, ligand, and base to give the second intermediate, carbazole dibenzothiophene. S03 reacts the second intermediate with iodomethane in the presence of anhydrous dichloromethane and aluminum trichloride to give the third intermediate; S04 The third intermediate was reacted with 2-chloroethanol in the presence of anhydrous dichloromethane and aluminum trichloride via a nucleophilic substitution reaction to give the fourth intermediate, a hydroxyethyl-substituted product. S05 The fourth intermediate is modified with functional groups to obtain the target product.

10. The preparation method according to claim 8, characterized in that: Includes the following steps S01 Obtain a substrate, wherein the substrate is a silicon solar cell; The hole transport layer is prepared by the SO2 solution method, and the material of the hole transport layer is... ； S03 Preparation of the perovskite layer: The perovskite layer contains perovskite material and additives, wherein the perovskite material is ABX3, and A is FA. + MA + Cs + The combination, B is Pb 2+ C is I - ,Br - The combination of the additives is MACl; S04 Preparation of the modification layer: The modification layer material is PEAI; S05 Preparation of the electron transport layer: The electron transport layer material is C 60 Material; S06 Preparation of hole blocking layer: The hole blocking layer material is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; S07 Electrode preparation.

Images