Perovskite solar cell device and preparation method

Abstract

The application discloses a perovskite solar cell device and a preparation method thereof, and belongs to the technical field of perovskite solar cell preparation. The perovskite solar cell device comprises, from top to bottom, a first electrode layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a second electrode layer, and a passivation layer is arranged between the electron transport layer and the perovskite light absorption layer. The passivation layer is made of a diphenylamine passivation agent. The chemical structural formula of the diphenylamine passivation agent is shown in the description, wherein R1-R10 are independently selected from hydrogen, C1-C6 alkyl, carboxyl, cyano, trifluoromethyl, halogen, phosphonic acid, C1-C6 alkyl sulfide and (CF3)3-C-. At least five substituents in R1-R10 are hydrogen. The diphenylamine passivation agent is used to effectively improve the stability and efficiency of the perovskite solar cell device.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell fabrication technology, and more specifically to a perovskite solar cell device and its fabrication method. Background Technology

[0002] Perovskite solar cells have stood out in the new energy field due to their low production cost and significantly improved power conversion efficiency in recent years, attracting widespread attention from numerous researchers and engineers. Compared with other traditional solar cell materials, perovskite semiconductor materials exhibit unique physical and chemical properties, such as long carrier diffusion length, strong defect tolerance, tunable bandgap range, high light absorption, and low exciton binding energy. These characteristics provide enormous potential for perovskite solar cells in terms of energy conversion efficiency.

[0003] Despite the numerous advantages of perovskite solar cells, their limited resistance to damp heat remains a key obstacle to their large-scale application. This performance limitation is generally attributed to the wettability and thermal instability of perovskite materials, leading to insufficient charge transfer characteristics in the fabricated perovskite layer and consequently affecting its power conversion efficiency. To address this issue, researchers have conducted in-depth investigations into defects in perovskite films, discovering that these defects are the main factors limiting their performance. Therefore, reducing the defect density in perovskite films and improving their quality and stability is crucial for manufacturing perovskite solar cells with high power conversion efficiency and long-term stability.

[0004] In traditional methods, reducing the defect density of the perovskite layer is mainly achieved by introducing passivating agents into the perovskite layer. These passivating agents can interact with defects in the perovskite material through ionic or coordination bonds, or transform defects into wide-bandgap materials to achieve passivation. However, existing passivation materials still have limitations in passivation effectiveness, such as incomplete passivation and poor stability, which further affect the performance of perovskite solar cells. Summary of the Invention

[0005] To address the above problems, this invention provides a perovskite solar cell device and its fabrication method. This invention uses diphenylamine passivating agents to effectively improve the stability and efficiency of the perovskite solar cell device.

[0006] The first objective of this invention is to provide a perovskite solar cell device, comprising, from top to bottom, a first electrode layer, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a second electrode layer, with a passivation layer provided between the electron transport layer and the perovskite light-absorbing layer.

[0007] The passivation layer is made of diphenylamine passivating agents; the chemical structural formula of the diphenylamine passivating agents is shown below:

[0008] .

[0009] R1 to R10 are each independently selected from one of hydrogen, C1 to C6 alkyl, carboxyl, cyano, trifluoromethyl, halogen, phosphonic acid, C1 to C6 alkyl thioether, and (CF3)3-C-; at least five of the substituents in R1 to R10 are simultaneously hydrogen.

[0010] This invention determines the flow of the electron cloud, the distortion of the molecular skeleton, and the embracing of molecules by placing substituents in different positions. Substituents in the ortho position exert steric hindrance and a strong internal effect; substituents in the para position provide maximum conjugation and no steric hindrance; and substituents in the meta position offer gentle electronic fine-tuning. For perovskite interface molecules: the carboxyl group in the ortho position can interact with Pb. 2+ Chelation passes off defects, while in the para position only weak interactions are possible.

[0011] In a preferred embodiment of the present invention, R1 to R10 are each independently selected from one of hydrogen, C1 to C3 alkyl, carboxyl, trifluoromethyl, bromine, cyano, phosphonic acid, C1 to C3 alkyl sulfide, and (CF3)3-C-.

[0012] In a preferred embodiment of the present invention, the diphenylamine passivating agent is one of the following compounds:

[0013] , , , , , , .

[0014] In diphenylamine passivators, when substituents are introduced onto the benzene ring, each group has a unique function and works synergistically. Hydrogen enhances the interaction between the passivator and the perovskite surface by forming hydrogen bonds, stabilizing the interface structure and reducing defect states to facilitate charge transport; alkyl groups alter the molecular conformation through steric hindrance, preventing harmful impurities from approaching and improving battery performance in humid environments through hydrophobicity; oxygen atoms in carboxyl groups form coordination bonds with metal ions on the perovskite surface, filling defect sites, reducing defect state density, and improving photoelectric conversion efficiency and stability; cyano groups, as strong electron-withdrawing groups, regulate the molecular electron cloud density, optimize charge transport paths, reduce charge load, and increase open-circuit voltage and fill factor; trifluoromethyl groups enhance hydrophobicity, making the battery more resistant to moisture, and their strong electron-withdrawing ability also affects the electronic structure of the perovskite surface. This improves charge injection and collection efficiency; halogens, with their electronegativity and ionic radius, form ionic bonds with perovskite lattice ions, passivating surface defects, optimizing crystal structure, and enhancing optical and electrical performance; phosphonic acid groups undergo chelation reactions with metal ions on the perovskite surface, repairing defect sites, enhancing bonding force, and improving long-term stability and efficiency; the lone pair electrons of sulfur atoms in thioether groups interact with unsaturated metal sites on the perovskite surface, filling defects and inhibiting charge recombination to improve performance; tri(trifluoromethyl)methyl groups provide significant steric hindrance due to their large spatial structure, enhancing molecular stability, and the strong hydrophobicity imparted by numerous trifluoromethyl groups greatly improves the stability and reliability of the battery in harsh environments.

[0015] A second objective of this invention is to provide a method for fabricating the above-mentioned perovskite solar cell device, comprising the following steps:

[0016] After cleaning, the conductive glass is pretreated to serve as the second electrode layer.

[0017] Pretreated conductive glass is subjected to ultraviolet ozone treatment to obtain a surface-treated conductive film. During the ultraviolet ozone treatment process, these organic pollutants are decomposed into small molecules such as carbon dioxide and water through photochemical reactions and oxidation, and are thus removed. In addition, the surface hydrophilicity can be improved, which is beneficial to the more uniform spread of the perovskite precursor solution on the glass surface during the subsequent solution spin coating process, forming a perovskite film with uniform thickness and good quality.

[0018] A hole transport layer material is coated onto a surface-treated conductive film, and then a first-step annealing process is performed under a nitrogen atmosphere to form a hole transport layer.

[0019] A perovskite precursor mixture solution is coated on the surface of the hole transport layer, and then a second annealing treatment is performed under a nitrogen atmosphere to form a perovskite light-absorbing layer.

[0020] A solution containing a diphenylamine passivating agent is coated on the surface of the perovskite light-absorbing layer, and then a third-step annealing treatment is performed under a nitrogen atmosphere to form a passivation layer.

[0021] An electron transport layer material is deposited on the passivation layer using a vacuum evaporation method to form an electron transport layer.

[0022] A first electrode layer is formed by depositing counter electrode material on the electron transport layer using a vacuum evaporation method, thus obtaining a perovskite solar cell device.

[0023] In a preferred embodiment of the present invention, the thickness of the passivation layer is 5 nm to 10 nm.

[0024] In a preferred embodiment of the present invention, the hole transport layer material is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly[3-(4-carboxylate butyl)]thiophene, or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and the thickness of the hole transport layer is 10 nm to 50 nm.

[0025] In a preferred embodiment of the present invention, the perovskite precursor has the structural formula APbX3, wherein the A-site is at least one of formamidinium cation, methylamine cation, and cesium ion; and the X-site is Cl... - ,Br - and I - At least one of the following; the thickness of the perovskite light-absorbing layer is 200 nm to 800 nm.

[0026] In a preferred embodiment of the present invention, the electron transport layer material is one or more of tin dioxide, titanium dioxide, fullerene, methyl [6,6]-phenyl C61 butyrate, zinc oxide, and lithium fluoride, and the thickness of the electron transport layer is 5 nm to 180 nm.

[0027] In a preferred embodiment of the present invention, the counter electrode material is silver, gold or carbon, and the thickness of the first electrode layer is 10 nm to 150 nm.

[0028] In a preferred embodiment of the present invention, the annealing temperature of the first annealing process is 100°C and the annealing time is 10 min to 15 min.

[0029] The second annealing process involves annealing at 100℃ for 30-35 minutes.

[0030] The third step of annealing involves annealing at 100℃ for 5 to 10 minutes.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention utilizes diphenylamine compounds as passivating agents, and the passivation material constructed based on the parent structure of the diphenylamine molecule exhibits a unique structure-property relationship. Its core structure consists of two benzene rings bridged by a planar conjugated nitrogen atom, forming a butterfly-shaped molecular framework. In this special configuration, a p-π conjugation effect is formed between the lone pair electrons of the nitrogen atom and the π-electron system of the benzene rings. This not only endows the molecule with a rigid planar structure but also enhances the delocalization ability of the molecular electrons. This delocalization effect allows the molecule to exhibit stronger electronic control capabilities on the perovskite surface. Furthermore, the special arrangement of the two benzene rings in three-dimensional space creates a molecular clamp effect. Specifically, the two benzene rings are arranged in a V-shape, forming a hydrophobic barrier on the perovskite surface, thereby improving the hydrophobicity of the material, enhancing the contact angle, and resulting in excellent hydrophobicity of the perovskite surface. This synergistic effect of the two hydrophobic benzene rings further enhances the passivation effect and reduces the influence of the external environment on the perovskite surface. The central nitrogen atom, as the key to molecular electronic control, interacts with the uncoordinated Pb on the perovskite surface through its lone pair electrons. 2+ Strong coordination bonds are formed between ions, achieving effective passivation of surface defects in space. This process relies not only on steric hindrance but also on the chemical bonding of nitrogen atoms, which further stabilizes the interaction between molecules and the perovskite surface, significantly reducing the impact of surface defects and thus improving the stability and efficiency of the device. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the inverted tantalum solar cell used in this invention.

[0034] Figure 2 The diagram shows the current density-voltage characteristics of Examples 1 to 5 of this invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the diphenylamine passivating agents used in this invention, 2,4-dimethyldiphenylamine has the CAS number 25078-04-0, 4-bromodiphenylamine has the CAS number 54446-36-5, and the diphenylamine-dicarboxylic acid derivative has the CAS number 579-92-0. 2,4,6-tricyano-N-3',5'-dicyano-4'-ethyldiphenylamine and N-(3-cyano-4-ethylphenyl)-2-[tris(trifluoromethyl)methyl]aniline are self-designed molecules, and specific preparation processes are provided in the examples. The fluorinated tin oxide conductive glass is designated A22-TO2-23. Fluorinated tin oxide conductive glass is denoted as FTO.

[0037] Example 1

[0038] The fabrication process of perovskite solar cell devices is as follows:

[0039] Step 1: Cleaning the conductive substrate

[0040] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0041] Step 2: Fabrication of the hole transport layer

[0042] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0043] Step 3: Preparation of the perovskite light-absorbing layer

[0044] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0045] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0046] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0047] Step 4: Preparation of the passivation layer

[0048] The specific steps for preparing the passivation layer are as follows:

[0049] 2,4-Dimethyldiphenylamine was dissolved in isopropanol to prepare a passivation solution with a concentration of 0.5 mg / mL. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite light-absorbing layer, and the layer was spin-coated at 2000 rpm / s for 20 seconds to uniformly coat the surface of the perovskite light-absorbing layer film. The layer was then annealed at 100°C for 5 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 50 nm.

[0050] The molecular structure diagram of the 2,4-dimethyldiphenylamine passivation layer is shown below:

[0051] .

[0052] Step 5: Fabrication of the electron transport layer

[0053] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and methyl [6,6]-phenyl-C61-butyrate with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0054] Step Six: Preparation of the First Electrode Layer

[0055] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0056] Example 2

[0057] The fabrication process of perovskite solar cell devices is as follows:

[0058] Step 1: Cleaning the conductive substrate

[0059] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0060] Step 2: Fabrication of the hole transport layer

[0061] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0062] Step 3: Preparation of the perovskite light-absorbing layer

[0063] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0064] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0065] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0066] Step 4: Preparation of the passivation layer

[0067] The specific steps for preparing the passivation layer are as follows:

[0068] 4-Bromodiphenylamine was dissolved in isopropanol to prepare a passivation solution with a concentration of 0.5 mg / mL. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite light-absorbing layer, and the layer was spin-coated at 2000 rpm / s for 20 seconds to uniformly coat the surface of the perovskite light-absorbing layer film. The layer was then annealed at 100°C for 5 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 50 nm.

[0069] The molecular structure diagram of 4-bromodiphenylamine is shown below:

[0070] .

[0071] Step 5: Fabrication of the electron transport layer

[0072] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and methyl [6,6]-phenyl-C61-butyrate with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0073] Step Six: Preparation of the First Electrode Layer

[0074] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0075] Example 3

[0076] The fabrication process of perovskite solar cell devices is as follows:

[0077] Step 1: Etching and cleaning of the conductive substrate

[0078] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0079] Step 2: Fabrication of the hole transport layer

[0080] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0081] Step 3: Preparation of the perovskite light-absorbing layer

[0082] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0083] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0084] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0085] Step 4: Preparation of the passivation layer

[0086] The specific steps for preparing the passivation layer are as follows:

[0087] A passivation solution with a concentration of 0.5 mg / mL was prepared by dissolving a diphenylamine-phosphonic acid derivative in isopropanol. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite light-absorbing layer, and the layer was spin-coated at 2000 rpm for 20 seconds to uniformly coat the surface of the perovskite light-absorbing layer film. The layer was then annealed at 100 °C for 5 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 50 nm.

[0088] The molecular structure diagram of the diphenylamine-phosphonic acid derivative is shown below:

[0089] .

[0090] Step 5: Fabrication of the electron transport layer

[0091] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and methyl [6,6]-phenyl-C61-butyrate with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0092] Step Six: Preparation of the First Electrode Layer

[0093] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0094] Example 4

[0095] The fabrication process of perovskite solar cell devices is as follows:

[0096] Step 1: Etching and cleaning of the conductive substrate

[0097] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0098] Step 2: Fabrication of the hole transport layer

[0099] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0100] Step 3: Preparation of the perovskite light-absorbing layer

[0101] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0102] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0103] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0104] Step 4: Preparation of the passivation layer

[0105] The specific steps for preparing the passivation layer are as follows:

[0106] A passivation solution with a concentration of 0.5 mg / mL was prepared by dissolving a diphenylamine-thioether-trifluoromethyl derivative in isopropanol. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite light-absorbing layer, and the layer was spin-coated at 2000 rpm for 20 seconds to uniformly coat the surface of the perovskite light-absorbing layer film. The layer was then annealed at 100 °C for 5 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 50 nm.

[0107] The molecular structure diagram of the diphenylamine-thioether-trifluoromethyl derivative is shown below:

[0108] .

[0109] Step 5: Fabrication of the electron transport layer

[0110] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and methyl [6,6]-phenyl-C61-butyrate with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0111] Step Six: Preparation of the First Electrode Layer

[0112] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0113] Example 5

[0114] The fabrication process of perovskite solar cell devices is as follows:

[0115] Step 1: Etching and cleaning of the conductive substrate

[0116] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0117] Step 2: Fabrication of the hole transport layer

[0118] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0119] Step 3: Preparation of the perovskite light-absorbing layer

[0120] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0121] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0122] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0123] Step 4: Preparation of the passivation layer

[0124] The specific steps for preparing the passivation layer are as follows:

[0125] A passivation solution with a concentration of 0.5 mg / mL was prepared by dissolving a diphenylamine-dicarboxylic acid derivative in isopropanol. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite light-absorbing layer, and the layer was spin-coated at 2000 rpm / s for 20 seconds to uniformly coat the surface of the perovskite light-absorbing layer film. The layer was then annealed at 100 °C for 5 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 50 nm.

[0126] The molecular structure diagram of the diphenylamine-dicarboxylic acid derivative is shown below:

[0127] .

[0128] Step 5: Fabrication of the electron transport layer

[0129] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and PCBM with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0130] Step Six: Preparation of the First Electrode Layer

[0131] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0132] Example 6

[0133] The fabrication process of perovskite solar cell devices is as follows:

[0134] Step 1: Cleaning the conductive substrate

[0135] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0136] Step 2: Fabrication of the hole transport layer

[0137] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate PEDOT:PSS with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 60 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 12 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of about 10 nm.

[0138] Step 3: Preparation of the perovskite light-absorbing layer

[0139] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0140] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0141] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 33 minutes under a nitrogen atmosphere to obtain a perovskite light-absorbing layer with a thickness of 700 nm.

[0142] Step 4: Preparation of the passivation layer

[0143] The specific steps for preparing the passivation layer are as follows:

[0144] 2,4,6-Tricyano-N-3',5'-dicyano-4'-ethyldiphenylamine was dissolved in isopropanol to prepare a passivation solution with a concentration of 0.5 mg / mL. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite absorbing layer, and the layer was spin-coated at 2000 rpm / s for 60 seconds to uniformly coat the surface of the perovskite absorbing layer film. The layer was then annealed at 100°C for 8 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 5 nm.

[0145] The molecular structure diagram of 2,4,6-tricyano-N-3',5'-dicyano-4'-ethyldiphenylamine is shown below:

[0146] .

[0147] The preparation process of 2,4,6-tricyano-N-3',5'-dicyano-4'-ethyldiphenylamine is as follows:

[0148] First, 5.00 g of 3,5-dicyanobromobenzene and 4.80 g of vinyl borate alcohol ester were placed in a reaction vessel. The vessel was evacuated and purged with nitrogen, repeated three times to replace the air. Then, 50 mL of degassed 1,4-dioxane and 25 mL of a 2 mol / L potassium carbonate aqueous solution were added. Immediately, 555 mg of 0.8 mmol of catalyst Pd(PPh3)4 was added, and the vessel was purged with nitrogen again. The reaction system was heated to 90 °C and stirred vigorously at this temperature for 12 hours. After the reaction was complete, the mixture was cooled to room temperature. The mixture was extracted with ethyl acetate, the organic phases were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The purified product was a white solid of 3,5-dicyanostyrene.

[0149] Dissolve 4.20 g of 3,5-dicyanostyrene obtained in the previous step in 60 mL of anhydrous ethanol and add the solution to a high-pressure reactor. Add 450 mg of 10% Pd / C catalyst. Stir the reaction at room temperature (25°C) for 6 hours. After the reaction is complete, filter to recover the Pd / C catalyst and wash the catalyst thoroughly with ethanol. Combine the filtrate and washings, and remove the solvent by rotary evaporation to obtain a colorless oily liquid, 3,5-dicyanoethylbenzene. It should be noted that 10% Pd / C refers to 10 g of Pd and 90 g of C per 100 g of the catalyst, and it is commercially available.

[0150] In an ice-water bath, 3.70 g of 3,5-dicyanoethylbenzene was dissolved in 20 mL of 98% concentrated sulfuric acid. A mixed acid consisting of 2 mL of 90% fuming nitric acid and 10 mL of 98% concentrated sulfuric acid was slowly added dropwise. The reaction was continued at 0°C with stirring for 2 hours. The reaction solution was carefully quenched in 100 g of crushed ice, resulting in the precipitation of a solid. The solid was filtered, washed, and dried to obtain the crude product.

[0151] 4.10 g of the crude product was added to a mixed solution of 40 mL ethanol and 10 mL concentrated hydrochloric acid (98% by mass). 21.0 g of stannous chloride dihydrate was added, carefully controlling the addition rate to prevent excessive reaction. The mixture was heated to 80 °C and reacted for 3 hours. The product was extracted with dichloromethane, washed, dried, filtered, and concentrated to obtain a pale yellow solid, 3,5-dicyano-4-ethylaniline.

[0152] In a dry round-bottom flask, 4.72 g of 1,3,5-tribromobenzene, 6.70 g of cuprous cyanide, and 45 mL of DMF were added. Under nitrogen protection and with magnetic stirring, the mixture was heated to 150 °C and reacted for 24 hours. After the reaction was complete, the reaction solution was slowly poured into 200 mL of vigorously stirred FeCl3 solution to remove unreacted cuprous cyanide and the byproduct hydrogen cyanide. The solution was extracted with ethyl acetate, washed, and dried to obtain a white solid, 2,4,6-tricyanobromobenzene. In this step, the FeCl3 solution was prepared by adding 20 g of FeCl3 to 200 mL of dilute hydrochloric acid (1 mol / L).

[0153] In a nitrogen-filled glove box, 3.20 g of 2,4,6-tricyanobromobenzene, 3.10 g of 3,5-dicyano-4-ethylaniline, 8.20 g of cesium carbonate, and 435 mg of 4,5-bis(diphenylphosphine)-9,9-dimethyloxanthracene were added to a reaction flask. 50 mL of anhydrous toluene was added, and the mixture was stirred to disperse the solids. 345 mg of tris(dibenzylacetone)dipalladium was added, the flask was sealed, and the mixture was heated to 110 °C and stirred for 20 hours. After the reaction was complete, the mixture was cooled to room temperature. The insoluble solids were removed by filtration through a diatomaceous earth filter and the mixture was thoroughly washed with dichloromethane. The filtrate was washed with saturated ammonium chloride solution, separated, and the aqueous phase was back-extracted with dichloromethane. The combined organic phases were washed with saturated brine and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated under reduced pressure to obtain a crude solid product. The target product, 2,4,6-tricyano-N-3',5'-dicyano-4'-ethyldiphenylamine, was obtained by reversed-phase column chromatography purification.

[0154] Step 5: Fabrication of the electron transport layer

[0155] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, tin dioxide with a thickness of 2 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, and titanium dioxide with a thickness of 3 nm was deposited at an evaporation rate of 0.1 Å / s, thereby forming an electron transport layer.

[0156] Step Six: Preparation of the First Electrode Layer

[0157] Gold electrodes were fabricated using vacuum evaporation. A 50 nm thick layer of gold was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 100 nm thick layer of gold at an evaporation rate of 0.4 Å / s, resulting in a gold electrode with a total thickness of 150 nm, ultimately yielding a complete perovskite solar cell device.

[0158] Example 7

[0159] The fabrication process of perovskite solar cell devices is as follows:

[0160] Step 1: Cleaning the conductive substrate

[0161] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, the FTO conductive glass surface was further surface-treated for 30 minutes using ultraviolet ozone treatment technology with a purity greater than 90%, serving as the second electrode layer.

[0162] Step 2: Fabrication of the hole transport layer

[0163] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate PEDOT:PSS with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 20 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 15 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of about 50 nm.

[0164] Step 3: Preparation of the perovskite light-absorbing layer

[0165] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0166] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0167] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 35 minutes under a nitrogen atmosphere to obtain a perovskite light-absorbing layer with a thickness of 700 nm.

[0168] Step 4: Preparation of the passivation layer

[0169] The specific steps for preparing the passivation layer are as follows:

[0170] N-(3-cyano-4-ethylphenyl)-2-[tris(trifluoromethyl)methyl]aniline was dissolved in isopropanol to prepare a passivation solution with a concentration of 0.5 mg / mL. Subsequently, 40 μL of the passivation solution was dropped onto the perovskite absorbing layer, and the layer was spin-coated at 2000 rpm / s for 60 seconds to uniformly coat the surface of the perovskite absorbing layer film. The layer was then annealed at 100 °C for 10 minutes under a nitrogen atmosphere to form a passivation layer with a thickness of 10 nm.

[0171] The molecular structure diagram of N-(3-cyano-4-ethylphenyl)-2-[tris(trifluoromethyl)methyl]aniline is shown below:

[0172] .

[0173] Synthetic preparation process of N-(3-cyano-4-ethylphenyl)-2-[tris(trifluoromethyl)methyl]aniline:

[0174] The synthesis of this molecule can be achieved through a three-step reaction, starting with commercially available raw materials, sequentially constructing an aromatic amine fragment containing a cyano group and an ethyl group, and then an aromatic amine fragment containing a tris(trifluoromethyl)methyl group, finally connecting the two fragments through a coupling reaction. The specific process is as follows:

[0175] First, in a 100 mL three-necked flask, 1.212 g (1.0 equivalent) of 4-ethylaniline was dissolved in 10 mL of analytical grade glacial acetic acid. The flask was placed in an ice-salt bath at 0 °C, and 11 mmol (1.758 g (1.1 equivalent) of bromine was slowly added dropwise. After 30 min of addition, the mixture was stirred for 1.5 h. After the reaction was completed, the mixture was extracted with dichloromethane and concentrated to obtain 2-bromo-4-ethylaniline with a purity ≥95% and a yield of 82%.

[0176] Subsequently, using 10 mmol (2.41 g, 1.0 equivalent) of the brominated product 2-bromo-4-ethylaniline as a starting material, and 12 mmol (1.08 g, 1.2 equivalent) of cuprous cyanide in 15 mL of anhydrous N-methylpyrrolidone, the reaction was carried out in a 50 mL sealed reaction vessel at 180 °C in an oil bath for 8 h. After the reaction was completed, excess copper ions were removed by complexation with ethylenediaminetetraacetic acid aqueous solution, followed by extraction with ethyl acetate and purification by silica gel column chromatography to finally obtain a pale yellow solid intermediate A, namely 3-cyano-4-ethylaniline, with a purity ≥98%. In this step, the bromine needs to be diluted with 2 mL of glacial acetic acid before use.

[0177] Next, in a 100 mL three-necked flask, 1.38 g (1.0 equivalent) of o-nitroaniline was dissolved in 20 mL of anhydrous 1,2-dichloroethane. 2.00 g (1.5 equivalent, 15 mmol) of anhydrous aluminum trichloride was added, along with the Lewis acid-activated chlorinated product. After heating to an 80 °C oil bath, 2.646 g (1.2 equivalent, 12 mmol) of tris(trifluoromethyl)methyl chloride was slowly added dropwise. The solution was diluted with 5 mL of anhydrous 1,2-dichloroethane. The total addition time was 40 min. After the addition was complete, the reaction was refluxed for 4 h. After the reaction was complete, the reaction solution was quenched in ice water and extracted and concentrated to obtain 2-nitro-6-[tris(trifluoromethyl)methyl]benzene with a purity ≥94% and a yield of 90%.

[0178] Using 3.17 g of 2-nitro-6-[tris(trifluoromethyl)methyl]benzene as a starting material, it was dissolved in 15 mL of anhydrous ethanol. 1.68 g of iron powder and 10 mmol of dilute hydrochloric acid were added, and the mixture was reacted at 78 °C under ethanol reflux for 3 h. After the reaction was complete, the iron was removed by filtration, neutralization extraction was performed, and the mixture was purified by silica gel column chromatography to obtain a colorless oily intermediate B, namely 2-[tris(trifluoromethyl)methyl]aniline, with a purity ≥96%. The dilute hydrochloric acid was obtained by adding 0.83 mL of 37% HCl to 10 mL of water.

[0179] Using 10 mmol of intermediate A as a baseline, the target molecule was synthesized by linking two fragments via Ullmann coupling reaction. The specific preparation method is as follows:

[0180] In a 50 mL three-necked flask, 1.72 g of intermediate A and 2.79 g of intermediate B were added in a 1:1 molar ratio. Using 20 mL of anhydrous o-dichlorobenzene as solvent, 0.064 g of copper powder as a catalyst, 2.76 g of anhydrous potassium carbonate, and 0.18 g of 1,10-phenanthroline were added. After purging the air three times with nitrogen, the mixture was refluxed in an oil bath at 180 °C for 12 h. After the reaction was complete, the mixture was cooled, filtered to remove residue, and the filtrate was concentrated under reduced pressure to obtain a crude product. This product was then subjected to gradient elution by silica gel column chromatography. Products with a purity <98% were further recrystallized to obtain the target molecule, N-(3-cyano-4-ethylphenyl)-2-[tris(trifluoromethyl)methyl]aniline, as white crystals. In this step, potassium carbonate was used to neutralize protons, and 1,10-phenanthroline was used to stabilize the catalyst activity.

[0181] Step 5: Fabrication of the electron transport layer

[0182] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, zinc oxide with a thickness of 60 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, titanium dioxide with a thickness of 80 nm was deposited at an evaporation rate of 0.1 Å / s, and C with a thickness of 40 nm was deposited at an evaporation rate of 0.15 Å / s. 60 This forms an electron transport layer.

[0183] Step Six: Preparation of the First Electrode Layer

[0184] Carbon electrodes were fabricated using vacuum evaporation. A 5 nm thick layer of carbon was deposited on the electron transport layer thin film at an evaporation rate of 0.2 Å / s, followed by another 5 nm thick layer of carbon at an evaporation rate of 0.4 Å / s, resulting in a carbon electrode with a total thickness of 10 nm, ultimately yielding a complete perovskite solar cell device.

[0185] Comparative Example 1

[0186] The fabrication process of perovskite solar cell devices is as follows:

[0187] Step 1: Etching and cleaning of the conductive substrate

[0188] Fluorine-doped tin oxide conductive glass was used as the substrate material. The conductive glass underwent a series of cleaning treatments: it was immersed in detergent and ultrasonically cleaned for 40 minutes; then immersed in deionized water and ultrasonically cleaned for 40 minutes; finally, it was immersed in ethanol and isopropanol solvents respectively and ultrasonically cleaned for 40 minutes to remove surface impurities; and finally, a high-purity ultraviolet ozone treatment was used to further treat the FTO conductive glass surface for 30 minutes, serving as the second electrode layer.

[0189] Step 2: Fabrication of the hole transport layer

[0190] On the second electrode layer of the FTO substrate, 100 μL of an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid with a concentration of 1 mol / mL was spin-coated at 5000 rpm / s for 30 seconds. After spin-coating, the sample was placed on a hot stage and annealed at 100°C for 10 minutes under a nitrogen atmosphere to form a stable hole transport layer with a thickness of approximately 20 nm.

[0191] Step 3: Preparation of the perovskite light-absorbing layer

[0192] A perovskite precursor mixture solution was spin-coated onto the surface of the hole transport layer. The chemical formula of this perovskite light-absorbing layer is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3.

[0193] The preparation process of the perovskite precursor mixed solution is as follows: 1.1 mol / L PbI₂, 0.2 mol / L MABr, 0.2 mol / L PbBr₂, 1 mol / L FAI, and 0.06 mol / L CsI were dissolved in 1250 μL of a mixed solution consisting of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The solution was shaken at room temperature for 3 hours. Before spin coating, the solution was filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to obtain the perovskite precursor mixed solution.

[0194] The perovskite thin film was prepared using a one-step method. The substrate was placed on a spin coater, and 50 μL of a perovskite precursor mixture was dropped onto the surface of the hole transport layer. Spin-coating was performed first at 2000 rpm / s for 10 seconds, followed by spin-coating at 5000 rpm / s for 30 seconds. Eighteen seconds before the start of spin-coating at 5000 rpm / s, 150 μL of the antisolvent chlorobenzene was added dropwise. After spin-coating, the film was annealed at 100°C for 30 minutes under a nitrogen atmosphere to obtain a perovskite thin film with a thickness of 700 nm.

[0195] Step 4: Fabrication of the electron transport layer

[0196] Electron transport layers were prepared using vacuum evaporation technology, with a density lower than 5 × 10⁻⁶. -4 Under Pa pressure, lithium fluoride with a thickness of 3 nm was deposited on the passivation layer film at an evaporation rate of 0.15 Å / s, fullerene with a thickness of 35 nm was deposited at an evaporation rate of 0.1 Å / s, and methyl [6,6]-phenyl-C61-butyrate with a thickness of 8 nm was deposited at an evaporation rate of 0.15 Å / s, thereby forming an electron transport layer.

[0197] Step 5: Fabrication of the first electrode layer

[0198] Silver electrodes were prepared using vacuum evaporation. A 50 nm thick Ag layer was deposited on the electron transport layer film at an evaporation rate of 0.2 Å / s, followed by a 70 nm thick Ag layer at an evaporation rate of 0.4 Å / s, resulting in an Ag electrode with a total thickness of 120 nm, ultimately yielding a complete perovskite solar cell device.

[0199] The performance of perovskite solar cells was tested using an AM1.5G standard solar spectrum simulator under environmental conditions of 25°C, humidity below 30%, and nitrogen atmosphere. The test results are shown in Table 1.

[0200] Table 1 Performance parameters of perovskite solar cells in Application Examples 1-5 and Comparative Example 1

[0201]

[0202] The results in Table 1 show that the perovskite thin film modified with diphenylamine passivator exhibits a significant improvement in photoelectric conversion efficiency compared to the unpassivated film. Similar to Examples 1-5, the perovskite solar cells prepared in Examples 6 and 7 demonstrate excellent photoelectric conversion efficiencies of 25.01% and 25.21%, respectively.

[0203] Figure 2 The current density-voltage characteristic diagrams of the perovskite solar cell devices prepared in Examples 1 to 5 are shown below. Figure 2 It can be seen that the devices fabricated in different embodiments maintain a high current density in the low voltage range of 0V to 0.8V, with a current density close to 25mA / cm². 2 The device exhibits good photocurrent output stability; however, when the voltage increases to approximately 0.8V–1.0V, the current density begins to decrease rapidly. Comparing different embodiments, the current density-voltage characteristic diagrams of Comparative Example 1 and various application embodiments differ. The current density-voltage characteristic diagrams of different embodiments show differences in the current density decay trend and final cutoff voltage at high voltage ranges, reflecting the influence of different passivating agents on the photoelectric conversion performance of the device, such as key parameters like open-circuit voltage and short-circuit current. Example 5 shows relatively better performance in current density maintenance and voltage tolerance, or demonstrates better performance in carrier separation, transport, and interface characteristics.

[0204] This invention is the first to use diphenylamine for interface passivation, focusing on solving the hydrophobic protection and defect passivation at the interface between the perovskite layer and air. This is completely different from existing technologies that focus on hole transport layer design or interface carrier extraction optimization. Existing technologies mainly use diphenylamine structures in hole transport materials of perovskite solar cells, serving as structural modifications. For example, patent CN113149849A discloses a fully conjugated organic molecule with spirofluorene as the core, trapezoidal fluorene as the arms, and diphenylamine end caps, used as a high-performance hole transport material. This structure improves the conjugation and thermal stability of the molecule, making it suitable for hole transport layers in light-emitting devices and solar cells. Patent CN113277972A uses diphenylamine as an outer substituent, hybridizing a carbazole / fluorene HTM framework structure. By enhancing the molecular steric hindrance effect, it effectively improves film quality and hole migration capability, thereby increasing device efficiency and processing stability. In addition, Yu Ming Hsuan et al. published "Impact of self-assembled monolayer structural design on perovskite phase regulation, hole-selective contact, and energy loss in inverted perovskite solar cells" in Nano Energy, Volume 132, 2024, reporting a self-assembled monolayer structure with triphenylamine end groups, which is used as an interface layer between the perovskite and hole-selective contact layer in the inverted structure. Its role is mainly reflected in energy level regulation and non-radiative recombination suppression.

[0205] However, the above-mentioned technical solutions differ from the present invention, which designs diphenylamine molecules as passivating agents specifically for perovskite surfaces, and also fails to fully utilize the synergistic effect of the amino group coordination ability and the hydrophobic structure of the benzene ring in terms of perovskite-air interface stability. Compared with the prior art, the present invention proposes for the first time to directly apply diphenylamine-like small molecules with specific structures to the surface of perovskite thin films to construct a passivation layer. Through the coordination of amino groups with unsaturated metal ions, surface defect states are significantly reduced, and non-radiative recombination is suppressed. At the same time, the double benzene ring structure endows the film with excellent hydrophobicity, effectively improving the stability of perovskite devices operating in air. Unlike the complex macromolecular materials used in hole transport layers, the present invention uses small molecule passivating agents, which can not only form a uniform coating on the thin film surface, but also improve the overall optoelectronic performance and lifespan of the device without introducing additional phase transitions or crystal phase interference.

[0206] CN116410227B discloses a phosphonic acid compound containing anisole / anisole thioether-based carbazole. Its core structure includes carbazole, anisole / anisole thioether, and phosphonic acid. The interfacial bonding is phosphate-anchored perovskite. The hydrogen bonding of anisole thioether is beneficial to improving environmental stability. However, the synthesis of this phosphate compound is difficult. The diphenylamine passivating agent used in this invention is easy to modify and more easily industrialized as a passivating agent. When the substitution site is phosphonic acid, thioether, or trifluoromethyl, the hole transport capability can be effectively improved through heterogeneous bridging. This allows the diphenylamine passivating agent to have both high mobility and passivation capability. Phosphonic acid and thioether can be dual passivated, thus providing more comprehensive defect passivation. When the substituent is trifluoromethyl, its hydrophobicity can improve moisture resistance.

[0207] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0208] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A perovskite solar cell device, comprising, from top to bottom, a first electrode layer, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a second electrode layer, characterized in that, A passivation layer is provided between the electron transport layer and the perovskite light-absorbing layer; The passivation layer is made of a diphenylamine passivating agent; the diphenylamine passivating agent is one of the following compounds: 、 、 、 、 、 、 。 2. A method for fabricating the perovskite solar cell device according to claim 1, characterized in that, Includes the following steps: After cleaning, the conductive glass is pretreated to serve as the second electrode layer. A surface-treated conductive film is obtained by subjecting pretreated conductive glass to ultraviolet ozone treatment. A hole transport layer material is coated on a surface-treated conductive film, and then a first-step annealing process is performed in a nitrogen atmosphere to form a hole transport layer. A perovskite precursor mixture solution is coated on the surface of the hole transport layer, and then a second annealing treatment is performed under a nitrogen atmosphere to form a perovskite light-absorbing layer. A solution containing a diphenylamine passivating agent is coated on the surface of the perovskite light-absorbing layer, and then a third-step annealing treatment is performed under a nitrogen atmosphere to form a passivation layer. An electron transport layer material is deposited on the passivation layer using a vacuum evaporation method to form an electron transport layer. A first electrode layer is formed by depositing counter electrode material on the electron transport layer using a vacuum evaporation method, thus obtaining a perovskite solar cell device.

3. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The thickness of the passivation layer is 5nm to 10nm.

4. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The hole transport layer material is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly[3-(4-carboxylate butyl)]thiophene, or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and the thickness of the hole transport layer is 10 nm to 50 nm.

5. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The perovskite precursor has the structural formula APbX3, where the A-site is at least one of a formamidinium cation, a methylamine cation, and a cesium ion; and the X-site is Cl-. - ,Br - and I - At least one of the following; the thickness of the perovskite light-absorbing layer is 200 nm to 800 nm.

6. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The electron transport layer material is one or more of tin dioxide, titanium dioxide, fullerene, methyl [6,6]-phenyl C61 butyrate, zinc oxide and lithium fluoride, and the thickness of the electron transport layer is 5 nm to 180 nm.

7. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The counter electrode material is silver, gold, or carbon, and the thickness of the first electrode layer is 10 nm to 150 nm.

8. The method for fabricating a perovskite solar cell device according to claim 2, characterized in that, The annealing temperature for the first annealing step is 100℃, and the annealing time is 10 min to 15 min. The second annealing process involves annealing at 100℃ for 30-35 minutes. The third step of annealing involves annealing at 100℃ for 5 to 10 minutes.

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