Perovskite photovoltaic device containing polyfluorinated aryl phosphine compound and preparation method thereof

Abstract

The invention provides a perovskite photovoltaic device containing a polyfluorinated aryl phosphine compound and a preparation method thereof, and relates to the technical field of perovskite photovoltaic devices, the perovskite photovoltaic device comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, an electron blocking layer and a back electrode layer; wherein a polyfluorinated aryl phosphine compound is added to the upper surface or the bulk phase of the perovskite light absorption layer, and the polyfluorinated aryl phosphine compound is specifically one or more of tris (3-fluorophenyl) phosphine, tris (pentafluorophenyl) phosphine and tris (4-trifluoromethylphenyl) phosphine. The method is suitable for bulk phase doping or surface modification, and the photoelectric conversion efficiency (up to 24.63%) and long-term stability (1000-hour efficiency retention rate gt; 90%) of the device are remarkably improved. The method is high in process compatibility, and an efficient and reliable solution is provided for commercial application of the perovskite solar cell.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite photovoltaic devices, and particularly to a perovskite photovoltaic device containing a polyfluoroarylphosphine compound and a preparation method thereof. Background Art

[0002] As a new type of photovoltaic material, organic-inorganic hybrid perovskite has become a research hotspot in the field of solar cells due to its excellent optoelectronic properties, preparation cost advantages, and rich raw material reserves. With the continuous breakthroughs in materials engineering and device processes, the conversion efficiency of this type of solar cell has achieved leapfrog development and gradually approaches the efficiency level of mainstream crystalline silicon solar cells, and is considered to be the third-generation solar cell with the most commercialization potential.

[0003] Although perovskite solar cells have made breakthroughs in photoelectric conversion efficiency, their industrialization process is still restricted by multiple challenges caused by the intrinsic defects of the materials: ① insufficient long-term stability caused by ion migration within the perovskite lattice, which is prone to phase separation and chemical degradation under conditions such as humidity and heat, and light; ② non-radiative recombination losses caused by high-density defect states at the surface / grain boundaries, which limit the theoretical limit of the open-circuit voltage of the device; ③ due to the ionic crystal characteristics of perovskite materials and the volatility of organic components, they are highly sensitive to the external environment (humidity, oxygen, light, etc.), resulting in rapid degradation of the device under water and oxygen penetration. To address the above bottlenecks, precise molecular-scale regulation has become the core strategy for optimizing device performance. The current mainstream methods focus on three types of molecular engineering: 1) additive engineering (such as introducing molecules with lone pairs of electrons to anchor lead sites), 2) interface modification (constructing two-dimensional / three-dimensional heterojunctions to inhibit ion diffusion), and 3) component engineering (enhancing phase stability through multiple doping of A-site cations). Summary of the Invention

[0004] Aiming at the problem that although perovskite solar cells have made breakthroughs in photoelectric conversion efficiency, their industrialization process is still restricted by multiple challenges caused by the intrinsic defects of the materials in the above-mentioned background art, the present invention proposes a perovskite photovoltaic device containing a polyfluoroarylphosphine compound and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect of the present invention, there is provided a perovskite photovoltaic device containing a polyfluoroarylphosphine compound, wherein the perovskite photovoltaic device includes a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, and a back electrode layer; wherein, a polyfluoroarylphosphine compound is added to the upper surface or bulk phase of the perovskite light-absorbing layer.

[0006] As a further illustration of the present invention, the polyfluoroarylphosphine compound is specifically one or more of tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine. For the molecules of the above compounds, the substituent functional groups at different positions on the aromatic ring include 3-15 fluorine atoms, and the fluorine atoms are from one or more of direct substitution on the benzene ring and trifluoroformic acid.

[0007] The present invention uses polyfluoroaryl-substituted organophosphine compounds, including tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine. Through the controllable design of different substitution sites (ortho, meta, para) and fluorination degrees (monofluoro to perfluoro) on the benzene ring, the steric hindrance and electronic properties of the molecules can be controllably adjusted to optimize the molecular interface interaction and hydrophobicity. Specifically: 1) Fluorine atoms directly anchor the uncoordinated lead ions on the surface and grain boundaries of perovskite through strong coordination, inhibit deep-level defect states, and reduce non-radiative recombination losses; 2) Fluorine atoms form with the free in perovskite to form dipole interactions, compensate for halogen vacancies, and enhance lattice integrity; + 3) The high hydrophobicity of the fluorinated aromatic ring forms a dense molecular layer on the perovskite surface. By forming a hydrogen bond network with + ions, it blocks the penetration of water and oxygen, and improves the overall photothermal stability of the device. At the same time, the phosphino group acts as an auxiliary site to coordinate with lead defects through lone pair electrons, and cooperates with fluorine atoms to achieve multi-dimensional defect passivation.

[0008] 4) The steric hindrance effect of the tridentate ligand can regulate the crystallization kinetics of perovskite, inhibit the formation of halogen vacancies at grain boundaries, reduce the ion migration barrier, and thus improve the open-circuit voltage (V OC ) and fill factor (FF) of the device.

[0009] Through the above interface regulation strategy dominated by fluorine atoms, the present invention not only improves the photoelectric conversion efficiency of the device, but also significantly enhances its long-term stability, providing a new path for the preparation of highly efficient and stable perovskite solar cells.

[0010] When the above fluorinated phosphine molecules are used as an independent interface layer to modify the upper surface of perovskite in the present invention, the fluorinated aryl group at the molecular end can further anchor the surface dangling lead sites through strong interaction to achieve multiple defect passivation. The hydrophobicity of perfluoro substituents such as pentafluorophenyl can form a physical barrier to block the erosion of moisture on the interface. From the perspective of energy level matching, the strong electron-withdrawing effect of the fluorinated aromatic ring can lower the LUMO energy level of the phosphine molecule, forming a gradient energy level arrangement with the perovskite conduction band, promoting electron extraction and inhibiting interface charge accumulation, and finally improving the short-circuit current density (JSC ) and stability.

[0011] When the phosphine fluoride molecule and PEAI co-modify the interface, the ammonium group (-NH3 + ) of PEAI can form a hydrogen bond network with the fluorine atoms in the phosphine molecule to construct a dense and ordered composite passivation layer. PEAI preferentially passivates the surface iodine vacancies, while the phosphine molecule repairs the lead defects through P→Pb coordination bonds, and the two form a synergistic passivation effect with complementary space and energy levels. In addition, the low-dimensional perovskite layer induced by PEAI and the fluorinated aromatic ring of the phosphine molecule produce π-π stacking, enhancing the coherence of the interface charge transport channel. At the same time, the three-dimensional / two-dimensional heterojunction structure further inhibits ion migration, enabling the device to maintain high stability under the aging conditions of 85 °C / 85% RH.

[0012] The phosphine fluoride molecule of the present invention can be flexibly applied on the upper surface and in the bulk phase of the perovskite light-absorbing layer to achieve multi-dimensional defect passivation. Its molecular structure design is chemically compatible with traditional passivators such as phenethylammonium iodide, and a composite protection layer can be constructed by superposition. This technology has no selective requirements for processes such as spin coating and blade coating, and the device efficiency is stable > 20%.

[0013] As a further illustration of the present invention, the chemical general formula of the perovskite light-absorbing layer is ABX n ; A + is selected from one or more of FA + [CH(NH2)2 + , MA + (CH3NH3 + ), Cs + ; B is selected from one or more of Pb 2+ , Sn 2+ , Rb + ; X is selected from one or more of Cl - , Br - , I - .

[0014] The second aspect of the present invention provides a preparation method of the perovskite photovoltaic device containing the polyfluoroarylphosphine compound as described above, including the following steps: Step 1: Coating a hole transport layer solution on a pretreated conductive substrate, and then performing annealing treatment to obtain a hole transport layer; Step 2: Coating a perovskite precursor solution on the hole transport layer, and forming a perovskite light-absorbing layer after annealing treatment, wherein a polyfluoroarylphosphine compound is added on the upper surface or in the bulk phase of the perovskite light-absorbing layer; Step 3: An electron transport layer and an electron blocking layer are sequentially prepared on the perovskite light-absorbing layer, and a metal electrode is prepared above the electron blocking layer to obtain a back electrode layer, and finally a perovskite photovoltaic device containing a polyfluoroarylphosphine compound is obtained.

[0015] As a further illustration of the present invention, the conductive substrate is pretreated with ultraviolet ozone or plasma.

[0016] As a further illustration of the present invention, in Step 1, the hole transport layer solution is spin-coated on the conductive substrate, and the hole transport layer is prepared after annealing treatment. Among them, [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) is dissolved in a dimethoxyethanol solution to prepare the hole transport layer solution. The spin-coating speed is 3000-6000 rpm, the spin-coating time is 10-40 s, the heat treatment temperature is 100-130 °C, and the treatment time is 10-30 min.

[0017] As a further illustration of the present invention, the coating means in Step 1 and Step 2 of the present invention can select processes such as spin coating and blade coating, and specifically, spin coating process can be preferably selected. In Step 3 of the present invention, the method of sequentially preparing the electron transport layer and the electron blocking layer on the perovskite light-absorbing layer can adopt processes such as spin coating and blade coating, and specifically, spin coating process can be preferably selected.

[0018] As a further illustration of the present invention, the preparation process of the perovskite precursor solution in Step 2 is carried out in an anhydrous and oxygen-free nitrogen glove box; the perovskite precursor is dissolved in an organic solvent to obtain the perovskite precursor solution, and it is heated and stirred at 20~80 °C for 2~12 h, and finally a perovskite precursor solution with a concentration of 1.0-2.0 M is obtained; among them, the organic solvent for dissolving the perovskite precursor is selected from one or more of N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone. When there are two kinds, the volume ratio of the two organic solvents in the mixed solvent is 6:1~2:1.

[0019] As a further illustration of the present invention, the perovskite precursor is a mixture prepared according to the molar ratio of CsI, MAI, FAI, PbI2 and PbBr2 of 0.05:0.9025:0.0475:0.925:0.075.

[0020] As a further illustration of the present invention, when a polyfluoroarylphosphine compound is added to the perovskite light-absorbing layer bulk phase, Step 2 is specifically: The polyfluoroarylphosphine compound is dissolved in a first organic solvent to obtain a polyfluoroarylphosphine molecular passivator solution; The polyfluoroarylphosphine molecular passivator is mixed with the perovskite precursor solution, and then coated on the conductive substrate with a hole transport layer, and after annealing treatment, a perovskite light-absorbing layer is formed.

[0021] As a further illustration of the present invention, the first organic solvent is one or more of acetonitrile, isopropanol, dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone.

[0022] As a further illustration of the present invention, the concentration range of the polyfluoroarylphosphine molecular passivator solution is 0.01 - 50 mg / mL, and for example, it can be 0.01 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 10 mg / mL, 20 mg / mL, 50 mg / mL, etc.

[0023] As a further illustration of the present invention, when the polyfluoroarylphosphine molecular passivator solution is mixed with the perovskite precursor solution, the volume ratio of the polyfluoroarylphosphine molecular passivator solution to the perovskite precursor solution is 1:100 - 1:5, and for example, it can be 1:100, 1:80, 1:50, 1:30, 1:10, 1:5, etc.

[0024] As a further illustration of the present invention, when adding a polyfluoroarylphosphine compound to the upper surface of the perovskite light-absorbing layer, step 2 specifically includes the following process: Coat the perovskite precursor solution on a conductive substrate with a hole transport layer, and form a perovskite light-absorbing layer after annealing treatment; Dissolve the polyfluoroarylphosphine compound in a second organic solvent to obtain a polyfluoroarylphosphine molecular modifier solution; Coat the polyfluoroarylphosphine molecular modifier solution on the perovskite light-absorbing layer, and form a first upper interface modification layer after annealing treatment.

[0025] As a further illustration of the present invention, step 2 further includes: Dissolve phenethylammonium iodide in a second organic solvent to obtain a phenethylammonium iodide molecular additive solution; Coat the phenethylammonium iodide molecular additive solution on the first upper interface modification layer to form a second upper interface modification layer.

[0026] As a further illustration of the present invention, the second organic solvent is one or more of methanol, isopropanol, 2-methoxypropanol, and chlorobenzene.

[0027] As a further illustration of the present invention, the concentration of the polyfluoroarylphosphine molecular modifier solution is 0.01 - 50 mg / mL, for example, it can be 0.01 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 10 mg / mL, 20 mg / mL, 50 mg / mL, etc.; the concentration of the phenethylammonium iodide molecular additive solution is 0.1 - 10 mg / mL, for example, it can be 0.1 mg / mL, 0.3 mg / mL, 0.5 mg / mL, 1 mg / mL, 5 mg / mL, 10 mg / mL, etc.

[0028] As a further illustration of the present invention, in step 2, the perovskite precursor solution is spin-coated on the hole transport layer. Specifically, the spin-coating speed is 3000 - 6000 rpm, the spin-coating time is 10 - 60 s, the annealing heat treatment temperature is 100 - 160 °C, and the treatment time is 10 - 30 min.

[0029] As a further illustration of the present invention, in step 2, the polyfluoroarylphosphine molecular modifier solution is spin-coated on the perovskite light-absorbing layer. Specifically, the spin-coating speed is 2000 - 4000 rpm, the spin-coating time is 10 - 30 s, the annealing heat treatment temperature is 70 - 100 °C, and the treatment time is 5 - 10 min.

[0030] As a further illustration of the present invention, in step 2, the phenethylammonium iodide molecular additive solution is spin-coated on the first upper interface modification layer. Specifically, the spin-coating speed is 2000 - 4000 rpm, the spin-coating time is 10 - 30 s, the annealing heat treatment temperature is 70 - 100 °C, and the treatment time is 5 - 10 min.

[0031] As a further illustration of the present invention, in step 3, the electron transport layer solution is spin-coated on the perovskite light-absorbing layer, and the electron transport layer is prepared after heat treatment. Among them, [6,6]-phenyl-C61-butyric acid isooctyl ester (PCBM) is dissolved in chlorobenzene to prepare the electron transport layer solution. The spin-coating speed is 2000 - 4000 rpm, the spin-coating time is 10 - 40 s, the heat treatment temperature is 70 - 100 °C, and the treatment time is 5 - 10 min.

[0032] As a further illustration of the present invention, in step 3, the electron blocking layer solution is spin-coated on the electron transport layer, and the electron blocking layer is prepared after heat treatment. Among them, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) is dissolved in isopropanol to prepare the electron blocking layer solution. The spin-coating speed is 2000 - 4000 rpm, the spin-coating time is 10 - 40 s, the heat treatment temperature is 70 - 100 °C, and the treatment time is 5 - 10 min.

[0033] As a further illustration of the present invention, in step 3, a metal electrode is prepared by thermal evaporation above the electron blocking layer to obtain a back electrode layer. The conditions for thermal evaporation are a vacuum degree lower than 5×10 -4 Pa.

[0034] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention uses organophosphorus compounds substituted with polyfluoroaryl groups to controllably adjust the steric hindrance and electronic properties of molecules, and optimize the molecular interface interaction and hydrophobicity. Fluorine atoms directly anchor the uncoordinated lead defects on the surface and grain boundaries of perovskite through strong coordination, inhibit ion migration and non-radiative recombination. At the same time, a dipole interaction is formed with free halogen ions to compensate for lattice vacancies and enhance structural stability. The strong hydrophobicity of the highly fluorinated aromatic ring can also form a dense physical barrier on the perovskite surface. Through the multiple synergistic mechanisms of fluorine atoms, defect repair and long-term protection functions are realized, providing a new strategy for the preparation of highly efficient and stable perovskite solar cells.

[0035] Other features and advantages of the present technical solution will be described in the subsequent description. And, partly, it will become obvious from the description, or be understood by implementing the present technical solution. The objectives and other advantages of the present technical solution can be achieved and obtained through the structures specifically pointed out in the written description and the drawings.

[0036] Next, through the drawings and embodiments, the technical solution of the present technical solution will be further described in detail. Description of the Drawings

[0037] The drawings are used to provide a further understanding of the present technical solution, and constitute a part of the description. Together with the embodiments of the present technical solution, they are used to explain the present technical solution and do not constitute a limitation to the present technical solution. In the drawings: Figure 1 is a structural diagram of a perovskite solar cell with molecular bulk addition, upper interface modification and double-layer modification with phenethylammonium iodide of the present invention; Figure 2 in which (a), (b), and (c) are respectively the structural diagrams of tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine molecules; Figure 3 is the current-voltage curve of the perovskite solar cell with tris(3-fluorophenyl)phosphine molecular bulk addition prepared in Example 1 of the present invention; Figure 4 is the current-voltage curve of the perovskite solar cell with tris(pentafluorophenyl)phosphine molecular bulk addition prepared in Example 2 of the present invention; Figure 5Current-voltage curve of the perovskite solar cell with bulk addition of tris(4-trifluoromethylphenyl)phosphine prepared in Example 3 of the present invention; Figure 6 Among them, (a) is the current-voltage curve of the perovskite solar cell with upper interface modification of tris(3-fluorophenyl)phosphine prepared in Example 4 of the present invention, and (b) is the AFM image of the perovskite layer in Example 4; Figure 7 Among them, (a) is the current-voltage curve of the perovskite solar cell with upper interface modification of tris(pentafluorophenyl)phosphine prepared in Example 5 of the present invention, and (b) is the AFM image of the perovskite layer in Example 5; Figure 8 Among them, (a) is the current-voltage curve of the perovskite solar cell with upper interface modification of tris(4-trifluoromethylphenyl)phosphine prepared in Example 6 of the present invention, and (b) is the AFM image of the perovskite layer in Example 6; Figure 9 Current-voltage curve of the perovskite solar cell with double-layer interface modification of tris(pentafluorophenyl)phosphine and phenethylammonium iodide prepared in Example 7 of the present invention; Figure 10 Current-voltage curve of the perovskite solar cell with double-layer interface modification of tris(3-fluorophenyl)phosphine and phenethylammonium iodide prepared in Example 8 of the present invention; Figure 11 Current-voltage curve of the perovskite solar cell with double-layer interface modification of tris(4-trifluoromethylphenyl)phosphine and phenethylammonium iodide prepared in Example 9 of the present invention; Figure 12 Among them, (a) is the current-voltage curve of the perovskite solar cell prepared in Comparative Example 1 of the present invention, and (b) is the AFM image of the perovskite layer in Comparative Example 1; Figure 13 It is a comparative graph of the stability curves of the perovskite solar cells with upper interface modification of tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine prepared respectively under the conditions of Examples 1, 5, and 7 and the perovskite solar cell prepared in Comparative Example 1. Among them, the perovskite device efficiencies in Examples 1, 2, and 3 were all measured at the same time point and normalized for easy effect comparison. Detailed implementation manners

[0038] The following describes the preferred embodiments of the technical solution with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the technical solution and are not used to limit the technical solution.

[0039] Example 1: Tris(3-fluorophenyl)phosphine molecules are doped into the perovskite precursor solution for the preparation of perovskite solar cells.

[0040] S1: Prepare the molecular passivator solution: In the environment of a nitrogen glove box, N,N-dimethylformamide and dimethyl sulfoxide are mixed according to a volume ratio of 4:1, and an appropriate amount of tris(3-fluorophenyl)phosphine molecules are dissolved to obtain a molecular passivator solution with a concentration of 0.05 mg / mL. S2: Prepare the molecular passivation-perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, then dissolve CsI, MAI, FAI, PbI2, and PbBr2 according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075 therein. Subsequently, add dropwise the molecular passivator solution prepared in S1 into the perovskite precursor solution, where the volume ratio of the added molecular passivator solution to the perovskite precursor solution is 1:20. Then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Prepare the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it in the center of the ITO glass. After spin-coating for 40 s, heat-treat it at 110 °C for 15 min to obtain the hole transport layer substrate. S4: Prepare the molecular passivation-perovskite light-absorbing layer: Pipette 50 μL of the molecular passivation-perovskite precursor solution and drop it in the center of the hole transport layer substrate, rotate it at a speed of 4000 rpm for 50 s, and add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Anneal and heat-treat it at 140 °C for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0041] S5: Preparation of the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isopropyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it on the perovskite light-absorbing layer. After heat treatment, the electron transport layer is obtained. Among them, the rotation speed of spin-coating is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0042] S6: Preparation of the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and pipette 100 μL of it and spin-coat it on the electron transport layer. After heat treatment, the electron blocking layer is obtained; among them, the rotation speed of spin-coating is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0043] S7: Preparation of the metal electrode layer: Using thermal evaporation method, evaporate 120 nm of silver above the electron blocking layer, where the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0044] As Figure 3 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 22.37%, and the effective area is 0.05 cm 2 .

[0045] Example 2: Dope tris(pentafluorophenyl)phosphine molecules into the perovskite precursor solution to fabricate a perovskite solar cell.

[0046] S1: Preparation of the molecular passivator solution: In the environment of a nitrogen glove box, mix N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, and dissolve an appropriate amount of tris(pentafluorophenyl)phosphine molecules to obtain a molecular passivator solution with a concentration of 0.05 mg / mL; S2: Preparation of the molecular passivation - perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, then dissolve CsI, MAI, FAI, PbI2 and PbBr2 according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075 in it. Subsequently, add the molecular passivator solution prepared in S1 dropwise into the perovskite precursor solution, where the volume ratio of the added molecular passivator solution to the perovskite precursor solution is 1:20. Then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 )0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Preparation of hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it in the center of the ITO glass. After spin-coating for 40 s, heat-treat it at 110 °C for 15 min to obtain a hole transport layer substrate; S4: Preparation of molecular passivation-perovskite light-absorbing layer: Pipette 50 μL of the molecular passivation-perovskite precursor solution and drop it in the center of the hole transport layer substrate. Spin at a speed of 4000 rpm for 50 s. Add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Under the condition of 140 °C, anneal and heat-treat for 30 min to form a perovskite thin film, and place it in a dry place for cooling.

[0047] S5: Preparation of electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isopropyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it on the perovskite light-absorbing layer. After heat treatment, an electron transport layer is obtained. Among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0048] S6: Preparation of electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and pipette 100 μL of it and spin-coat it on the electron transport layer. After heat treatment, an electron blocking layer is obtained; Among them, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0049] S7: Preparation of metal electrode layer: Using thermal evaporation method, evaporate 120 nm of silver above the electron blocking layer, where the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0050] As Figure 4 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 22.48%, and the effective area is 0.05 cm 2 .

[0051] Example 3: Dope tris(4-trifluoromethylphenyl)phosphine molecules into the perovskite precursor solution to prepare a perovskite solar cell.

[0052] S1: Preparation of molecular passivation agent solution: In an environment of a nitrogen glove box, N,N-dimethylformamide and dimethyl sulfoxide are mixed at a volume ratio of 4:1, and an appropriate amount of tris(4-trifluoromethylphenyl)phosphine molecules are dissolved to obtain a molecular passivation agent solution with a concentration of 0.05 mg / mL; S2: Preparation of molecular passivation-perovskite precursor solution: In an environment filled with nitrogen, first, a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide is mixed at a volume ratio of 4:1, and then CsI, MAI, FAI, PbI2, and PbBr2 are dissolved therein at a molar ratio of 0.05:0.9025:0.0475:0.925:0.075. Subsequently, the molecular passivation agent solution prepared in S1 is added dropwise to the perovskite precursor solution, where the volume ratio of the added molecular passivation agent solution to the perovskite precursor solution is 1:20. Then, it is stirred at 40 °C for 6 h, and finally, after filtration through a PTFE 0.22 μm filter head, a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Preparation of hole transport layer: The ITO conductive glass is placed in a plasma cleaner and treated for 25 min, and then transferred to a dry nitrogen glove box; [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) is dissolved in a dimethoxyethanol solution to prepare a hole transport layer solution. 50 μL of the hole transport layer solution is aspirated and dropped in the center of the ITO glass. After spin-coating for 40 s, it is heat-treated at 110 °C for 15 min to obtain a hole transport layer substrate; S4: Preparation of molecular passivation-perovskite light-absorbing layer: 50 μL of the molecular passivation-perovskite precursor solution is aspirated and dropped in the center of the hole transport layer substrate, and rotated at a speed of 4000 rpm for 50 s. 250 μL of ethyl acetate is added dropwise as an anti-solvent 10 s before the end of spin-coating. It is annealed and heat-treated at 140 °C for 30 min to form a perovskite thin film, and then placed in a dry place for cooling.

[0053] S5: Preparation of electron transport layer: [6,6]-phenyl-C61-butyric acid isooctyl ester (PCBM) is dissolved in chlorobenzene to prepare an electron transport layer solution. 50 μL of the electron transport layer solution is spin-coated on the perovskite light-absorbing layer, and after heat treatment, an electron transport layer is obtained. Among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0054] S6: Preparation of the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and pipette 100 μL of it onto the electron transport layer and spin-coat it. After heat treatment, the electron blocking layer is obtained. Among them, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0055] S7: Preparation of the metal electrode layer: Using thermal evaporation, evaporate 120 nm of silver above the electron blocking layer, where the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0056] As Figure 5 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 23.18%, and the effective area is 0.05 cm 2 .

[0057] Example 4: Using tris(3-fluorophenyl)phosphine molecule as an interface modifier to prepare a perovskite solar cell.

[0058] S1: Preparation of the molecular modifier: In a nitrogen glove box, dissolve tris(3-fluorophenyl)phosphine molecule with isopropanol as the solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Preparation of the perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvents of N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, and then dissolve CsI, MAI, FAI, PbI2 and PbBr2 according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075 in it, and then stir at 40 °C for 6 h. Finally, filter it through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Preparation of the hole transport layer: Put the ITO conductive glass into a plasma cleaner and process it for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution, pipette 50 μL of the hole transport layer solution, drop it in the center of the ITO glass, and after spin-coating for 40 s, heat-treat it at 110 °C for 15 min to obtain the hole transport layer substrate; S4: Preparation of perovskite light-absorbing layer: 50 μL of perovskite precursor solution was sucked and dropped onto the center of the hole transport layer substrate, and rotated at a speed of 4000 rpm for 50 s. 250 μL of ethyl acetate was added as an anti-solvent 10 s before the end of spin coating. After annealing treatment at 140 °C for 30 min, a perovskite thin film was formed and placed in a dry place for cooling.

[0059] S5: Preparation of upper interface modification layer: 50 μL of the molecular modifier solution prepared in S1 was sucked and dropped onto the perovskite light-absorbing layer, and rotated at a speed of 2000 rpm for 30 s. Then, it was heat-treated at 100 °C for 10 min to obtain the upper interface modification layer; S6: Preparation of electron transport layer: [6,6]-Phenyl-C61-butyric acid isomethyl ester (PCBM) was dissolved in chlorobenzene to prepare an electron transport layer solution. 50 μL of the electron transport layer solution was sucked and spin-coated on the perovskite light-absorbing layer-upper interface modification layer. After heat treatment, the electron transport layer was prepared, where the spin coating speed was 2000 rpm, the duration was 30 s, the heat treatment temperature was 70 °C, and the time was 5 min.

[0060] S7: Preparation of electron blocking layer: 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was dissolved in isopropanol to prepare an electron blocking layer solution, and 100 μL was sucked and spin-coated on the electron transport layer. After heat treatment, the electron blocking layer was prepared; where the spin coating speed was 4000 rpm, the duration was 30 s, the heat treatment temperature was 70 °C, and the time was 5 min.

[0061] S8: Preparation of metal electrode layer: Using thermal evaporation method, 120 nm of silver was evaporated above the electron blocking layer, where the evaporation condition was that the vacuum degree was lower than 5×10 -4 Pa.

[0062] As Figure 6 shown, the photoelectric conversion efficiency of the perovskite solar cell was measured to be 21.81%, and the effective area was 0.05 cm 2 .

[0063] Example 5: Using tris(pentafluorophenyl)phosphine molecule as an interface modifier, a perovskite solar cell was prepared: S1: Preparation of molecular modifier: In a nitrogen glove box, tris(pentafluorophenyl)phosphine molecule was dissolved with isopropanol as a solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Prepare the perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, and then dissolve CsI, MAI, FAI, PbI2, and PbBr2 in it according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075. Then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Prepare the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it in the center of the ITO glass. After spin-coating for 40 s, heat-treat at 110 °C for 15 min to obtain the hole transport layer substrate; S4: Prepare the perovskite light-absorbing layer: Pipette 50 μL of the perovskite precursor solution and drop it in the center of the hole transport layer substrate, rotate at a speed of 4000 rpm for 50 s, and add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Anneal at 140 °C for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0064] S5: Prepare the upper interface modification layer: Pipette 50 μL of the molecular modifier solution prepared in S1 and drop it on the perovskite light-absorbing layer, rotate at a speed of 2000 rpm for 30 s, and then heat-treat at 100 °C for 10 min to obtain the upper interface modification layer; S6: Prepare the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it on the perovskite light-absorbing layer-upper interface modification layer, and obtain the electron transport layer after heat treatment; among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0065] S7: Preparation of the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and aspirate 100 μL of it and spin-coat it on the electron transport layer. After heat treatment, the electron blocking layer is obtained. Among them, the rotation speed of spin-coating is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0066] S8: Preparation of the metal electrode layer: Using thermal evaporation, evaporate 120 nm of silver above the electron blocking layer. Among them, the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0067] As Figure 7 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 22.08%, and the effective area is 0.05 cm 2 .

[0068] Example 6: Using tris(4-trifluoromethylphenyl)phosphine molecule as an interface modifier, prepare a perovskite solar cell: S1: Preparation of the molecular modifier: In a nitrogen glove box, dissolve tris(4-trifluoromethylphenyl)phosphine molecule with isopropanol as the solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Preparation of the perovskite precursor solution: In an environment filled with nitrogen, first mix N,N-dimethylformamide and dimethyl sulfoxide mixed solvent according to a volume ratio of 4:1, and then dissolve CsI, MAI, FAI, PbI2 and PbBr2 according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075 in it, and then stir at 40 °C for 6 h. Finally, filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S3: Preparation of the hole transport layer: Put the ITO conductive glass into a plasma cleaner and process it for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution, aspirate 50 μL of the hole transport layer solution, drop it in the center of the ITO glass, and after spin-coating for 40 s, heat-treat it at 110 °C for 15 min to obtain the hole transport layer substrate; S4: Preparation of perovskite light-absorbing layer: Pipette 50 μL of perovskite precursor solution onto the center of the hole transport layer substrate, spin at a speed of 4000 rpm for 50 s, and add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin coating. Under the condition of 140 °C, anneal for 30 min to form a perovskite thin film, and place it in a dry place for cooling.

[0069] S5: Preparation of upper interface modification layer: Pipette 50 μL of the molecular modifier solution prepared in S1 onto the perovskite light-absorbing layer, spin at a speed of 2000 rpm for 30 s, and then heat-treat at 100 °C for 10 min to obtain the upper interface modification layer; S6: Preparation of electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin coat it on the perovskite light-absorbing layer-upper interface modification layer, and obtain the electron transport layer after heat treatment; among them, the spin coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0070] S7: Preparation of electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and pipette 100 μL and spin coat it on the electron transport layer, and obtain the electron blocking layer after heat treatment; among them, the spin coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0071] S8: Preparation of metal electrode layer: Use thermal evaporation method to evaporate 120 nm of silver above the electron blocking layer, among which, the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0072] As Figure 8 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 23.41%, and the effective area is 0.05 cm 2 .

[0073] Example 7: Use tris(3-fluorophenyl)phosphine molecule and phenethylammonium iodide as interface modifiers to prepare a perovskite solar cell: S1: Preparation of molecular modifier: In a nitrogen glove box, dissolve tris(3-fluorophenyl)phosphine molecule with isopropanol as a solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Preparation of phenethylammonium iodide molecular additive: In a nitrogen glove box, dissolve phenethylammonium iodide molecule with isopropanol as a solvent to obtain a molecular additive solution with a concentration of 1 mg / mL; S3: Prepare the perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1, and then dissolve CsI, MAI, FAI, PbI2, and PbBr2 in it according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075. Then stir for 6 h at 40 °C, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S4: Prepare the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it in the center of the ITO glass. After spin-coating for 40 s, heat-treat at 110 °C for 15 min to obtain the hole transport layer substrate; S5: Prepare the perovskite light-absorbing layer: Pipette 50 μL of the perovskite precursor solution and drop it in the center of the hole transport layer substrate, rotate at a speed of 4000 rpm for 50 s, and drop 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Under the condition of 140 °C, anneal and heat-treat for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0074] S6: Prepare the upper interface modification layer 1: Pipette 50 μL of the molecular modifier solution prepared in S1 and drop it on the perovskite light-absorbing layer, rotate at a speed of 2000 rpm for 30 s, and then heat-treat at 100 °C for 10 min to obtain the upper interface modification layer 1; S7: Prepare the upper interface modification layer 2: Pipette 50 μL of the molecular additive solution prepared in S2 and drop it on the perovskite light-absorbing layer - upper interface modification layer 1, rotate at a speed of 2000 rpm for 30 s, and then heat-treat at 100 °C for 10 min to obtain the upper interface modification layer 2; S8: Prepare the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it on the perovskite light-absorbing layer - upper interface modification layer 2, and obtain the electron transport layer after heat treatment; Among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0075] S9: Preparation of the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and aspirate 100 μL to spin-coat on the electron transport layer. After heat treatment, the electron blocking layer is obtained; wherein, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0076] S10: Preparation of the metal electrode layer: Using thermal evaporation method, evaporate 120 nm of silver above the electron blocking layer, wherein the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0077] As Figure 9 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 22.10%, and the effective area is 0.05 cm 2 .

[0078] Example 8: Using tris(pentafluorophenyl)phosphine molecule and phenethylammonium iodide as interface modifiers to prepare a perovskite solar cell: S1: Preparation of the molecular modifier: In a nitrogen glove box, dissolve the tris(pentafluorophenyl)phosphine molecule with isopropanol as the solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Preparation of the phenethylammonium iodide molecular additive: In a nitrogen glove box, dissolve the phenethylammonium iodide molecule with isopropanol as the solvent to obtain a molecular additive solution with a concentration of 1 mg / mL; S3: Preparation of the perovskite precursor solution: In an environment filled with nitrogen, first mix the N,N-dimethylformamide and dimethyl sulfoxide mixed solvent in a volume ratio of 4:1, then dissolve CsI, MAI, FAI, PbI2 and PbBr2 in a molar ratio of 0.05:0.9025:0.0475:0.925:0.075 therein, then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S4: Fabricating the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box. Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it onto the center of the ITO glass. After spin-coating for 40 s, heat-treat it at 110 °C for 15 min to obtain the hole transport layer substrate. S5: Fabricating the perovskite light-absorbing layer: Pipette 50 μL of the perovskite precursor solution and drop it onto the center of the hole transport layer substrate. Spin at a speed of 4000 rpm for 50 s. Add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Anneal at 140 °C for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0079] S6: Fabricating the first upper interface modification layer: Pipette 50 μL of the molecular modifier solution prepared in S1 and drop it onto the perovskite light-absorbing layer. Spin at a speed of 2000 rpm for 30 s, and then heat-treat it at 100 °C for 10 min to obtain the first upper interface modification layer. S7: Fabricating the second upper interface modification layer: Pipette 50 μL of the molecular additive solution prepared in S2 and drop it onto the perovskite light-absorbing layer - the first upper interface modification layer. Spin at a speed of 2000 rpm for 30 s, and then heat-treat it at 100 °C for 10 min to obtain the second upper interface modification layer. S8: Fabricating the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isopropyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it onto the perovskite light-absorbing layer - the second upper interface modification layer. After heat-treatment, obtain the electron transport layer. Among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat-treatment temperature is 70 °C, and the time is 5 min.

[0080] S9: Fabricating the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropyl alcohol to prepare an electron blocking layer solution, and pipette 100 μL of it and spin-coat it onto the electron transport layer. After heat-treatment, obtain the electron blocking layer. Among them, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat-treatment temperature is 70 °C, and the time is 5 min.

[0081] S10: Fabricating the metal electrode layer: Using thermal evaporation, evaporate 120 nm of silver above the electron blocking layer. Among them, the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0082] As Figure 10As shown, the photoelectric conversion efficiency of the perovskite solar cell was measured to be 22.88%, and the effective area was 0.05 cm 2 .

[0083] Example 9: Using tris(4-trifluoromethylphenyl)phosphine molecule and phenethylammonium iodide as interface modifiers, a perovskite solar cell was prepared: S1: Prepare the molecular modifier: In a nitrogen glove box, dissolve the tris(4-trifluoromethylphenyl)phosphine molecule with isopropanol as the solvent to obtain a molecular modifier solution with a concentration of 0.5 mg / mL; S2: Prepare the phenethylammonium iodide molecular additive: In a nitrogen glove box, dissolve the phenethylammonium iodide molecule with isopropanol as the solvent to obtain a molecular additive solution with a concentration of 1 mg / mL; S3: Prepare the perovskite precursor solution: In an environment filled with nitrogen, first mix the N,N-dimethylformamide and dimethyl sulfoxide mixed solvent in a volume ratio of 4:1, then dissolve CsI, MAI, FAI, PbI2, and PbBr2 in it in a molar ratio of 0.05:0.9025:0.0475:0.925:0.075, then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S4: Prepare the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution, aspirate 50 μL of the hole transport layer solution, drop it in the center of the ITO glass, and spin-coat for 40 s, then heat-treat at 110 °C for 15 min to obtain a hole transport layer substrate; S5: Prepare the perovskite light-absorbing layer: Aspirate 50 μL of the perovskite precursor solution and drop it in the center of the hole transport layer substrate, rotate at a speed of 4000 rpm for 50 s, and add 250 μL of ethyl acetate as an anti-solvent 10 s before the end of spin-coating. Anneal at 140 °C for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0084] S6: Preparation of the upper interface modification layer I: Pipette 50 μL of the molecular modifier solution prepared in S1 and drop it onto the perovskite light-absorbing layer, spin at a speed of 2000 rpm for 30 s, and then perform heat treatment at 100 °C for 10 min to obtain the upper interface modification layer I; S7: Preparation of the upper interface modification layer II: Pipette 50 μL of the molecular additive solution prepared in S2 and drop it onto the perovskite light-absorbing layer - upper interface modification layer I, spin at a speed of 2000 rpm for 30 s, and then perform heat treatment at 100 °C for 10 min to obtain the upper interface modification layer II; S8: Preparation of the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution, pipette 50 μL of the electron transport layer solution and spin-coat it onto the perovskite light-absorbing layer - upper interface modification layer II, and obtain the electron transport layer after heat treatment; among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0085] S9: Preparation of the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol to prepare an electron blocking layer solution, and pipette 100 μL of it and spin-coat it onto the electron transport layer, and obtain the electron blocking layer after heat treatment; among them, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0086] S10: Preparation of the metal electrode layer: Use thermal evaporation to evaporate 120 nm of silver above the electron blocking layer, where the evaporation condition is that the vacuum degree is lower than 5×10 -4 Pa.

[0087] As Figure 11 shown, the photoelectric conversion efficiency of the perovskite solar cell is measured to be 24.63%, and the effective area is 0.05 cm 2 .

[0088] Comparative Example 1: Without adding polyfluoroarylphosphine compounds tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine and tris(4-trifluoromethylphenyl)phosphine molecules as interface modifiers and molecular passivators, prepare the perovskite solar cell.

[0089] S1: Prepare the perovskite precursor solution: In an environment filled with nitrogen, first mix the mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide according to a volume ratio of 4:1, and then dissolve CsI, MAI, FAI, PbI2, and PbBr2 in it according to a molar ratio of 0.05:0.9025:0.0475:0.925:0.075. Then stir at 40 °C for 6 h, and finally filter through a PTFE 0.22 μm filter head to obtain a 1.55 M perovskite precursor solution Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 FA 0.95 Pb(I 0.95 Br 0.05 )3; S2: Prepare the hole transport layer: Place the ITO conductive glass in a plasma cleaner for 25 min, and then transfer it to a dry nitrogen glove box; Dissolve [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) in a dimethoxyethanol solution to prepare a hole transport layer solution. Pipette 50 μL of the hole transport layer solution and drop it in the center of the ITO glass. After spin-coating for 40 s, heat-treat at 110 °C for 15 min to obtain a hole transport layer substrate; S3: Prepare the perovskite light-absorbing layer: Pipette 50 μL of the perovskite precursor solution and drop it in the center of the hole transport layer substrate, rotate at a speed of 4000 rpm for 50 s, and under the condition of 140 °C, anneal and heat-treat for 30 min to form a perovskite thin film, and place it in a dry place to cool.

[0090] S4: Prepare the electron transport layer: Dissolve [6,6]-phenyl-C61-butyric acid isopropyl ester (PCBM) in chlorobenzene to prepare an electron transport layer solution. Pipette 50 μL of the electron transport layer solution and spin-coat it on the perovskite layer. After heat treatment, an electron transport layer is obtained; Among them, the spin-coating speed is 2000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0091] S5: Prepare the electron blocking layer: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropyl alcohol to prepare an electron blocking layer solution, and pipette 100 μL of it and spin-coat it on the electron transport layer. After heat treatment, an electron blocking layer is obtained; Among them, the spin-coating speed is 4000 rpm, the duration is 30 s, the heat treatment temperature is 70 °C, and the time is 5 min.

[0092] S6: Prepare the metal electrode layer: Use thermal evaporation to evaporate 120 nm of silver above the electron blocking layer. Among them, the evaporation condition is that the vacuum degree is lower than 5×10-4 Pa.

[0093] As Figure 12 shown, the photoelectric conversion efficiency of the perovskite solar cell was measured to be 19.29%, and the effective area was 0.05 cm 2 ; Comparing Comparative Example 1 with the data in Figures 3 - 11 it can be found that after molecular modification, both the open-circuit voltage and short-circuit current of the device have increased, indicating that after adding the polyfluoroarylphosphine compounds tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine molecules respectively, the deep-level defects in the perovskite are significantly passivated, non-radiative recombination is inhibited, and through the above-mentioned multifunctional molecular modification, the photoelectric conversion efficiency of the perovskite solar cell can be effectively improved.

[0094] As Figure 13 shown, compared with the perovskite devices interfacially modified with the polyfluoroaryl-substituted organophosphine compounds tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine molecules, the stability of Comparative Example 1 is poor; according to Figure 6 (b), 7(b), 8(b), 12(b) shown, after the upper interface modification with tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine molecules, the surface quality of the perovskite film is improved, the grain size increases and the arrangement is tight, indicating that tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine molecules can reduce the grain boundaries of the perovskite film, thereby significantly reducing the defect density, inhibiting non-radiative recombination, and enhancing the carrier lifetime and mobility; the surface roughness of the film is reduced, which is beneficial to the formation of a closer contact between the perovskite layer and the charge transport layer, reducing interface voids or uncovered areas, which can reduce the interface resistance, promote efficient charge extraction, and at the same time inhibit the hysteresis effect caused by ion migration at the interface; the dense and smooth perovskite film can block the environmental water and oxygen penetration path to delay the hydrolysis / oxidation of the perovskite lattice, and at the same time reduce surface unevenness to inhibit the formation of ion migration channels, improving the efficiency retention rate of the device under continuous light or thermal stress.

[0095] The above research results show that the polyfluoroaryl-substituted organophosphine compounds developed in this study - including tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine - can significantly improve the photoelectric conversion efficiency and long-term stability of perovskite solar cells. Mechanism research shows that such compounds improve the surface quality of the film and effectively enhance the optoelectronic performance of the device. It should be noted that based on the industrial-grade test standard, the optimized device can still maintain more than 92% of the initial efficiency after 1000 hours of high-temperature aging in a nitrogen environment, showing significant commercial application prospects.

[0096] Obviously, those skilled in the art can make various changes and modifications to this technical solution without departing from the spirit and scope of this technical solution. Thus, if these modifications and variations of this technical solution fall within the scope of the claims of this technical solution and its equivalent technologies, then this technical solution is also intended to include these changes and modifications.

Claims

1. A perovskite photovoltaic device containing a polyfluoroarylphosphine compound, characterized in that, The perovskite photovoltaic device includes a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, and a back electrode layer; wherein, a polyfluoroarylphosphine compound is added to the upper surface or the bulk phase of the perovskite light-absorbing layer.

2. The perovskite photovoltaic device containing a polyfluoroarylphosphine compound according to claim 1, characterized in that, The polyfluoroarylphosphine compound is specifically one or more of tris(3-fluorophenyl)phosphine, tris(pentafluorophenyl)phosphine, and tris(4-trifluoromethylphenyl)phosphine.

3. A method for preparing a perovskite photovoltaic device containing a polyfluoroarylphosphine compound as described in claim 1 or 2, characterized in that, It includes the following steps: Step 1: Coat a hole transport layer solution on a pretreated conductive substrate, and then perform annealing treatment to obtain a hole transport layer. Step 2: Coat a perovskite precursor solution on the hole transport layer, and form a perovskite light-absorbing layer after annealing treatment. Among them, a polyfluoroarylphosphine compound is added to the upper surface or the bulk phase of the perovskite light-absorbing layer. Step 3: Sequentially prepare an electron transport layer and an electron blocking layer on the perovskite light-absorbing layer, and prepare a metal electrode above the electron blocking layer to obtain a back electrode layer, and finally obtain a perovskite photovoltaic device containing a polyfluoroarylphosphine compound.

4. The method for preparing a perovskite photovoltaic device containing a polyfluoroarylphosphine compound according to claim 3, characterized in that, When adding a polyfluoroarylphosphine compound to the bulk phase of the perovskite light-absorbing layer, Step 2 is specifically: Dissolve the polyfluoroarylphosphine compound in a first organic solvent to obtain a polyfluoroarylphosphine molecular passivator solution. Mix the polyfluoroarylphosphine molecular passivator with the perovskite precursor solution, and then coat it on a conductive substrate with a hole transport layer, and form a perovskite light-absorbing layer after annealing treatment.

5. The preparation method of the perovskite photovoltaic device containing a polyfluoroarylphosphine compound according to claim 4, characterized in that, The first organic solvent is one or more of acetonitrile, isopropanol, dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone.

6. The method for preparing a perovskite photovoltaic device containing a polyfluoroarylphosphine compound according to claim 4, characterized in that, When the polyfluoroarylphosphine molecular passivator solution is mixed with the perovskite precursor solution, the volume ratio of the polyfluoroarylphosphine molecular passivator solution to the perovskite precursor solution is 1:100 - 1:

5.

7. The preparation method of the perovskite photovoltaic device containing the polyfluoroarylphosphine compound according to claim 3, characterized in that, When adding a polyfluoroarylphosphine compound to the upper surface of the perovskite light-absorbing layer, Step 2 specifically includes the following process: Coat the perovskite precursor solution on a conductive substrate with a hole transport layer, and form a perovskite light-absorbing layer after annealing treatment. Dissolve the polyfluoroarylphosphine compound in a second organic solvent to obtain a polyfluoroarylphosphine molecular modifier solution. Coat the polyfluoroarylphosphine molecular modifier solution on the perovskite light-absorbing layer, and form a first upper interface modification layer after annealing treatment.

8. The method for preparing a perovskite photovoltaic device containing a polyfluoroarylphosphine compound as claimed in claim 7, characterized in that, Step 2 further includes: Dissolve phenethylammonium iodide in a second organic solvent to obtain a phenethylammonium iodide molecular additive solution. Coat the phenethylammonium iodide molecular additive solution on the first upper interface modification layer to form a second upper interface modification layer.

9. The method for preparing a perovskite photovoltaic device containing a polyfluoroarylphosphine compound according to claim 7, characterized in that, The second organic solvent is one or more of methanol, isopropanol, 2-methoxypropanol, and chlorobenzene.

10. The preparation method of the perovskite photovoltaic device containing the polyfluoroarylphosphine compound according to claim 3, characterized in that, In Step 2, when spin-coating the perovskite precursor solution on the hole transport layer, the specific spin-coating speed is 3000 - 6000 rpm, the spin-coating time is 10 - 40 s, the annealing treatment temperature is 100 - 160 °C, and the treatment time is 10 - 30 min.

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