A method for preparing a perovskite film using L-4-fluorophenylalanine ethyl ester hydrochloride as a passivation agent

Abstract

This invention discloses a method for preparing perovskite thin films using L-4-fluorophenylalanine ethyl ester hydrochloride as a passivating agent. The method first prepares FTO / NiO x A SAM composite substrate was prepared, and a passivation solution and a ternary perovskite precursor solution were prepared under light-shielded conditions and filtered for later use. An initial perovskite film was then prepared using a one-step anti-solvent method, followed by spin-coating of the passivation solution. Finally, the film was heated at 100-105°C for 5 minutes to obtain a perovskite film with interface passivation treatment. This invention uses a specific amino acid ester hydrochloride as an interface passivating agent, which can efficiently passivate defects, inhibit ion migration, and improve crystal quality. The multilayer, stepwise preparation of the composite substrate optimizes interfacial contact, reduces the charge transport barrier, and thus improves the photoelectric conversion performance of the film.

Description

Technical Field

[0001] This invention relates to a method for preparing perovskite thin films using L-4-fluorophenylalanine ethyl ester hydrochloride as a passivating agent. Background Technology

[0002] As the core functional layer of perovskite optoelectronic devices, the quality and interface characteristics of perovskite thin films directly determine the optoelectronic performance and long-term operational stability of the devices. During the preparation of perovskite thin films, the interfacial structure of the substrate, the purity of the solution system, the control of the film deposition process, and the passivation treatment of interfacial defects are all key factors affecting the crystallinity, morphological regularity, and interfacial contact performance of the film.

[0003] However, existing perovskite thin film preparation processes rely on simple substrate cleaning and single-functional layer deposition, resulting in insufficient interfacial adhesion and poor substrate surface smoothness, which introduces potential defects for subsequent film growth. Furthermore, inadequate environmental control during precursor solution preparation easily introduces impurities and leads to poor solution dispersibility, resulting in uneven grain size and numerous grain boundaries during film formation. Additionally, improper timing and dosage of antisolvents during film formation result in surface morphology defects such as pinholes and cracks. Finally, while PDAI2, PDI, and EDAI2 are used as passivating agents in the passivation process, their poor stability leads to poor long-term operational stability of the resulting perovskite optoelectronic devices. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a method for preparing perovskite thin films that enable perovskite optoelectronic devices to have good photoelectric conversion efficiency and long-term operational stability.

[0005] Technical solution: The method for preparing perovskite thin films according to the present invention includes the following steps:

[0006] (1) Preparation of composite substrate: FTO glass was first ultrasonically cleaned and rinsed with ethanol, then treated with ultraviolet ozone, and then NiO was deposited by magnetron sputtering. x The FTO glass was first layered and then subjected to high-temperature calcination and plasma treatment. Finally, an ethanol solution of DCz-4P and an isopropanol solution of PEACI were sequentially spin-coated onto the FTO glass to obtain FTO / NiO. x / SAM composite substrate;

[0007] (2) Under light-protected conditions, L-4-fluorophenylalanine ethyl ester hydrochloride was added to a mixed solvent of isopropanol and chlorobenzene to prepare a passivation solution of 0.4~0.6 mg / mL. After ultrasonic dissolution, the solution was filtered. CsI, FAI (formamidinium hydroiodide), MACl (methylammonium chloride), PbI2 and Tween-80 were added to a mixed solvent of DMF and DMSO to prepare a 1.4 M (total molar concentration of CsI, FAI, MACl and PbI2) ternary perovskite precursor solution. After ultrasonic treatment, the solution was filtered. Brown glass sample bottles were used for solution preparation. The ultrasonic dissolution of the passivation solution was carried out at room temperature for 10~20 min. The total ultrasonic treatment time of the ternary perovskite precursor solution was not less than 30 min.

[0008] (3) The ternary perovskite precursor solution was dropped onto the center of the substrate and spin-coated using a one-step anti-solvent method. First, spin-coated at 1000-1200 rpm for 10-12 s, then spin-coated at 5000-5500 rpm for 30-32 s. During this stage, 240 μL of chlorobenzene was dropped on at 4-6 s. After spin-coating, the substrate was heated at 100-110℃ for 25-26 min (this step is to form the perovskite phase (the perovskite precursor solution will form a perovskite mesophase after the anti-solvent is added, and the subsequent annealing process is required to completely transform the perovskite mesophase into the perovskite phase)) to obtain the initial perovskite film.

[0009] (4) The passivation solution is dropped onto the center of the initial perovskite film after cooling, and spin-coated at a speed of 5000~5500 rpm for 30~35s; the perovskite film after spin-coating the passivation solution is transferred in an inert atmosphere for 20~30s to a heat treatment at 100~105℃ for 5~6min to obtain a perovskite film after interface passivation treatment; during the passivation annealing treatment, the time for the perovskite film after spin-coating the passivation solution to be transferred from the sample stage of the spin coater to the heating equipment shall not exceed 30s, and the transfer and heating processes shall be carried out in a nitrogen atmosphere, and the film shall be naturally cooled with the heating equipment after heating is completed.

[0010] In step (1), the ultrasonic cleaning time is 10-15 minutes. After ultrasonic cleaning with detergent for 10-15 minutes, the FTO glass is rinsed with ethanol (anhydrous ethanol) 3-5 times. A nitrogen gun is used to blow the glass surface dry in a single direction at a uniform speed. The nitrogen used in the nitrogen gun is high-purity nitrogen. The NiO... xThe layer thickness is 20-25 nm. During magnetron sputtering, argon and oxygen are introduced into the sputtering chamber. The argon flux is set to 100 sccm, and the oxygen flux is set to 0.5 sccm. The total magnetron sputtering time is 240 s, including 60 s pre-sputtering and 180 s formal sputtering. After sputtering, calcination is performed in an air atmosphere, followed by natural cooling in the furnace. The high-temperature calcination temperature is 400-500℃, and the calcination time is 10-12 h. The concentration of the ethanol solution of DCz-4P is 0.5-0.6 mg / mL, and the concentration of the isopropanol solution of PEACI is 1.0-1.2 mg / mL. The ethanol solution of DCz-4P is spin-coated at 3000-3500 rpm for 30-40 s and then heated at 100-150℃ for 10-15 min. The isopropanol solution of PEACI is spin-coated at 5000-6000 rpm for 30-40 s without annealing. In this invention, all spin coating operations are performed on a spin coater, and the substrate is fixed at the center of the sample stage of the spin coater during the spin coating process.

[0011] In step (2), the volume ratio of isopropanol to chlorobenzene in the mixed solvent of isopropanol and chlorobenzene is 1:1; the volume ratio of DMF to DMSO in the mixed solvent of DMF and DMSO is 8:2; the amount of Tween-80 added to the ternary perovskite precursor solution is 0.2 mol% (added to 0.2% of the molar amount of the perovskite precursor solution); filtration treatment refers to filtration through a 0.22 μm polytetrafluoroethylene filter; the mass ratio of CsI, FAI, MACl, and PbI2 is 18.18:204.64:14.17:645.41.

[0012] In step (3), during the initial film preparation, the composite substrate is left to stand in a nitrogen glove box for 5 minutes before the precursor solution is added. The amount of the ternary perovskite precursor solution added is 48~50 μL. The chlorobenzene is anhydrous chlorobenzene, and the amount of chlorobenzene added is 240~250 μL.

[0013] In step (4), during the spin coating of the passivation solution, the temperature of the initial perovskite film after cooling is consistent with the ambient temperature inside the nitrogen glove box, and the amount of passivation solution added is 38~40μL.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0015] (1) The method of the present invention can construct FTO / NiO with tight interfacial bonding and high surface flatness. x The SAM composite substrate provides a good foundation for the growth of perovskite thin films.

[0016] (2) The passivation solution and perovskite precursor solution prepared by the present invention have good uniformity and purity, thereby effectively reducing film defects caused by impurity particles.

[0017] (3) In the process of preparing the initial film, the present invention can make the perovskite grains grow in a directional and uniform manner by precisely controlling the spin coating parameters and the timing of adding the antisolvent, thereby forming an initial film with high crystallinity and regular morphology, and thus greatly improving the basic photoelectric properties of the film.

[0018] (4) In this invention, L-4-fluorophenylalanine ethyl ester hydrochloride (4-F-Phe-OEt, CAS: 1534-90-3) is used as a passivating agent, and low-temperature annealing is performed after passivation. The specific molecular structure of the passivating agent forms a precise bond with the defect sites on the surface of the perovskite film, thereby achieving efficient passivation of the interface defects of the film. This effectively suppresses the non-radiative recombination process and improves the carrier transport efficiency and lifetime. The entire passivation process is completed quickly in a nitrogen atmosphere, avoiding the formation of new defects when the film comes into contact with air during the process. At the same time, the low-temperature annealing process takes into account both the passivation effect and the improvement of the film structure stability, and can effectively prevent the perovskite phase decomposition caused by high temperature. The interface state density of the perovskite film after interface passivation is significantly reduced, and the interface contact characteristics are optimized. Finally, the perovskite film obtained has good photoelectric conversion efficiency and long-term operating stability. Attached Figure Description

[0019] Figure 1 The images show scanning electron microscope (SEM) images of the film obtained in Comparative Example 7 (without passivation treatment Pristine) and the perovskite film (Target) prepared in Example 1.

[0020] Figure 2 Atomic force microscopy (AFM) images of the thin film (without passivation treatment) obtained in Comparative Example 7 and the perovskite thin film prepared in Example 1.

[0021] Figure 3 The X-ray diffraction (XRD) spectra of the thin film obtained in Comparative Example 7 (without passivation treatment) and the perovskite thin film prepared in Example 1 are shown.

[0022] Figure 4 A schematic diagram of the device structure of a perovskite solar cell (a) and a scanning electron microscope (SEM) image of the cross-section of the battery device formed based on the thin film prepared in Example 1 (b).

[0023] Figure 5 The distribution of core performance parameters of perovskite solar cells obtained after treatment with different concentrations of passivating agent 4-F-Phe-OEt (Example 1, Example 3, Comparative Examples 1-2, Comparative Example 7);

[0024] Figure 6 JV curves of perovskite solar cells after treatment with different concentrations of passivating agent 4-F-Phe-OEt (Examples 1, 3, Comparative Examples 1-2, and Comparative Example 7) (a) and after treatment with different passivating agents (b);

[0025] Figure 7 The 300s steady-state output (SPO) test results are shown for the perovskite solar cell device formed based on the thin film obtained in Comparative Example 7 and the perovskite solar cell device formed based on the thin film obtained in Example 1.

[0026] Figure 8 XRD patterns of the thin film obtained in Comparative Example 7 (a) and the thin film obtained in Example 1 after 30 days of storage (b), and efficiency stability test diagram of the perovskite solar cell device formed by the thin film obtained after different passivation agent treatment after 30 days of storage (c).

[0027] Figure 9 Macroscopic morphology and SEM image of the thin film surface after 30 days of atmospheric storage of the thin film obtained in Example 1 and Comparative Example 7;

[0028] Figure 10 JV curves of perovskite solar cell devices formed from thin films based on DCz-4P with different concentrations are shown.

[0029] Figure 11 The performance parameter distribution of perovskite solar cell devices formed based on thin films with different concentrations of DCz-4P is shown.

[0030] Figure 12 JV curves of perovskite solar cell devices formed from thin films based on different concentrations of PEACI;

[0031] Figure 13 The morphology of the films obtained when the antisolvent was added at time points of 5 s (25) (Example 1), 3 s (26) and 1 s (27) (Comparative Example 7);

[0032] Figure 14 The morphology of the film (Comparative Example 8) obtained when the antisolvent was added at a time point of 10 s (No. 16);

[0033] Figure 15 The TRPL spectra of the perovskite films obtained in Example 1 and Comparative Example 7 are shown. Detailed Implementation

[0034] Example 1

[0035] The method for preparing perovskite thin films of the present invention includes the following steps:

[0036] (1) Preparation of composite substrate:

[0037] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol. After rinsing four times, the glass surface was dried uniformly in one direction using a high-purity nitrogen gun to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment (to remove residual organic glue and other substances on the glass surface, so that the subsequent deposition layer is more tightly bonded to the substrate). After treatment, the glass was quickly transferred to the sputtering chamber of the magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant (Ar flux was set to 100 sccm, O2 flux was set to 0.5 sccm, and DC frequency target sputtering was started for 240 s). The magnetron sputtering program was started for sputtering treatment, and a 20 nm thick NiO layer was sputtered on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to a heating device and calcined at 400℃ in an air atmosphere (calcination is to remove oxygen vacancies on the surface). The calcination lasts for 10 hours. After calcination, the heating device is turned off, and the substrate is allowed to cool naturally to room temperature with the furnace. After cooling, the substrate is cut and then placed in a plasma cleaning device for cleaning (plasma treatment uses argon ions to bombard the substrate surface, thereby improving the wettability of the solution on the substrate surface during the subsequent SAM formation process, resulting in a smoother substrate surface). The cleaning lasts for 40 seconds, completing the pretreatment operation of the substrate.

[0038] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0039] (2) Preparation of core solutions: All preparation operations of core solutions are carried out in a nitrogen glove box. Brown glass sample bottles are used as storage containers for all solutions. The solvents used in the preparation process, such as isopropanol, chlorobenzene, DMF (dimethylformamide), and DMSO (dimethyl sulfoxide), are all anhydrous solvents, ensuring that there are no impurities or contaminants in the solution preparation process from the source.

[0040] (2.1) Weigh a certain amount of L-4-fluorophenylalanine ethyl ester hydrochloride (1.2 mg), slowly add it to a 1:1 mixture of isopropanol and chlorobenzene, stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0041] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0042] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0043] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0044] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 100℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0045] Example 2

[0046] Example 2 is prepared in a manner that is basically the same as that of Example 1, except that in step (5), the annealing temperature is 105°C.

[0047] (1) Preparation of composite substrate:

[0048] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0049] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0050] (2) Preparation of core solution:

[0051] (2.1) Weigh a certain amount of L-4-fluorophenylalanine ethyl ester hydrochloride (1.2 mg), slowly add it to a 1:1 mixture of isopropanol and chlorobenzene, stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0052] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0053] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0054] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0055] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 105℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0056] Example 3

[0057] Example 3 is prepared in a manner that is basically the same as that of Example 1, except that in step (2), a passivation solution with a concentration of 0.4 mg / mL is prepared, specifically as follows:

[0058] (1) Preparation of composite substrate:

[0059] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0060] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0061] (2) Preparation of core solution:

[0062] (2.1) Weigh a quantitative amount of L-4-fluorophenylalanine ethyl ester hydrochloride (0.8 mg), slowly add it to a 1:1 volume ratio of isopropanol and chlorobenzene mixed solvent, stir thoroughly to prepare a passivation solution with a concentration of 0.4 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0063] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0064] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0065] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0066] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 105℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0067] Comparative Example 1

[0068] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that in step (2), a passivation solution with a concentration of 0.2 mg / mL is prepared, specifically as follows:

[0069] (1) Preparation of composite substrate:

[0070] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0071] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0072] (2) Preparation of core solution:

[0073] (2.1) Weigh a quantitative amount of L-4-fluorophenylalanine ethyl ester hydrochloride (0.4 mg), slowly add it to a 1:1 volume ratio of isopropanol and chlorobenzene mixed solvent, stir thoroughly to prepare a passivation solution with a concentration of 0.2 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0074] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0075] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0076] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0077] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 105℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0078] Comparative Example 2

[0079] The preparation method of Comparative Example 2 is basically the same as that of Example 1, except that in step (2), a passivation solution with a concentration of 0.8 mg / mL is prepared, specifically as follows:

[0080] (1) Preparation of composite substrate:

[0081] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0082] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0083] (2) Preparation of core solution:

[0084] (2.1) Weigh a quantitative amount of L-4-fluorophenylalanine ethyl ester hydrochloride (1.6 mg), slowly add it to a 1:1 mixture of isopropanol and chlorobenzene, stir thoroughly to prepare a passivation solution with a concentration of 0.8 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until no solid particles remain in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0085] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0086] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0087] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0088] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 105℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0089] Comparative Example 3

[0090] The preparation method of Example 3 is basically the same as that of Example 1, except that in step (5), the annealing temperature is 95°C, specifically:

[0091] (1) Preparation of composite substrate:

[0092] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0093] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0094] (2) Preparation of core solution:

[0095] (2.1) Weigh a certain amount of L-4-fluorophenylalanine ethyl ester hydrochloride (1.2 mg), slowly add it to a 1:1 mixture of isopropanol and chlorobenzene, stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL, place the brown glass sample bottle containing the passivation solution in an ultrasonic device, and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0096] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0097] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0098] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of 0.6 mg / mL L-4-fluorophenylalanine ethyl ester hydrochloride passivation solution (40 μL) after filtration. Slowly drop the passivation solution onto the center of the initial perovskite film. Fix the film after the passivation solution has been added back onto the center of the sample stage of the spin coater. Set the corresponding spin coating acceleration of the spin coater and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0099] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 95℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0100] Comparative Example 4

[0101] Comparative Example 4 was prepared in a basically the same way as Example 1, except that in step (2), the passivation solution was a 0.6 mg / mL PDAI2 (1,3-propanediamine dihydroiodide) passivation solution, specifically:

[0102] (1) Preparation of composite substrate:

[0103] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0104] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0105] (2) Preparation of core solution:

[0106] (2.1) Weigh a quantitative amount of PDAI2 (1,3-propanediamine dihydroiodide) (1.2 mg), and slowly add it to a mixed solvent of isopropanol and chlorobenzene with a volume ratio of 1:1. Stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL. Place the brown glass sample bottle containing the passivation solution in an ultrasonic device and perform ultrasonic dissolution at room temperature. Continue ultrasonication until there are no solid particles left in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0107] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0108] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0109] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of filtered 0.6 mg / mL PDAI2 passivation solution (40 μL) and slowly drop the passivation solution onto the center of the initial perovskite film. After the passivation solution has been added, fix the film on the sample stage of the spin coater again, set the corresponding spin coating acceleration of the spin coater, and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0110] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating equipment within 30 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating equipment is precisely set to 95℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating equipment is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating equipment, and finally the perovskite film with interface passivation treatment is obtained.

[0111] Comparative Example 5

[0112] Comparative Example 5 was prepared in a basically the same way as Example 1, except that in step (2), the passivation solution was a 0.6 mg / mL PDI (CAS: 58464-47-4) passivation solution, specifically:

[0113] (1) Preparation of composite substrate:

[0114] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0115] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0116] (2) Preparation of core solution:

[0117] (2.1) Weigh a certain amount of PDI (1.2 mg) and slowly add it to a 1:1 mixture of isopropanol and chlorobenzene. Stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL. Place the brown glass sample bottle containing the passivation solution in an ultrasonic device and perform ultrasonic dissolution at room temperature. Continue ultrasonication until no solid particles remain in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0118] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0119] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0120] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of filtered 0.6 mg / mL PDI passivation solution (40 μL) and slowly drop the passivation solution onto the center of the initial perovskite film. After the passivation solution has been added, fix the film on the sample stage of the spin coater again, set the corresponding spin coating acceleration of the spin coater, and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0121] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating device within 5 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating device is precisely set to 95℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating device is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating device, and finally the perovskite film with interface passivation treatment is obtained.

[0122] Comparative Example 5

[0123] Comparative Example 5 was prepared in a basically the same way as Example 1, except that in step (2), the passivation solution was a 0.6 mg / mL EDAI2 passivation solution, specifically:

[0124] (1) Preparation of composite substrate:

[0125] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0126] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0127] (2) Preparation of core solution:

[0128] (2.1) Weigh a certain amount of EDAI2 (ethylenediamine dihydroiodide, 1.2 mg), and slowly add it to a 1:1 mixture of isopropanol and chlorobenzene. Stir thoroughly to prepare a passivation solution with a concentration of 0.6 mg / mL. Place the brown glass sample bottle containing the passivation solution in an ultrasonic device and perform ultrasonic dissolution at room temperature. Continue ultrasonication until no solid particles remain in the solution. After dissolution, filter the passivation solution through a 0.22 μm polytetrafluoroethylene filter. Immediately after filtration, seal the brown glass sample bottle and place the sealed sample bottle in a nitrogen glove box for later use.

[0129] (2.2) Weigh out quantitative amounts of CsI, FAI, MACl, and PbI2 sequentially (the amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively). Add 0.2 mol% Tween-80 to the solution. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2. Stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0130] (3) Initial thin film preparation: FTO / NiO x The SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and the heating time was 25 minutes. After heating, the heating device was turned off and the substrate was allowed to cool naturally to room temperature to obtain the initial perovskite film.

[0131] (4) Spin coating of passivation solution: Place the prepared initial perovskite film in a nitrogen glove box and allow it to cool completely to the same temperature as the environment inside the nitrogen glove box. Then, use a pipette to slowly draw a quantitative amount of filtered 0.6 mg / mL EDAI2 passivation solution (40 μL) and slowly drop the passivation solution onto the center of the initial perovskite film. After the passivation solution has been added, fix the film on the sample stage of the spin coater again, set the corresponding spin coating acceleration of the spin coater, and spin coat the passivation solution onto the surface of the initial perovskite film at a speed of 5000 rpm. The spin coating duration is 30 s to ensure that the passivation solution can be uniformly and completely covered on the film surface.

[0132] (5) Passivation annealing treatment: After the spin coating operation of the passivation solution is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating device within 5 seconds. The entire transfer process is carried out under a nitrogen atmosphere, and the subsequent heating process is also kept in a nitrogen atmosphere without any change. The temperature of the heating device is precisely set to 95℃, and the perovskite film is heated for 5 minutes. After the heating is completed, the heating device is turned off, and the perovskite film is allowed to cool naturally to room temperature with the heating device, and finally the perovskite film with interface passivation treatment is obtained.

[0133] Example 7 - No passivation treatment was performed, specifically:

[0134] (1) Preparation of composite substrate:

[0135] (1.1) FTO glass was selected as the base substrate and ultrasonically cleaned in a neutral non-ionic glass cleaning solution for 12 minutes. After cleaning, the FTO glass was removed and the surface was repeatedly rinsed with anhydrous ethanol for 4 times. Then, a high-purity nitrogen gun was used to blow the glass surface dry in a single direction at a uniform speed to ensure that there was no liquid residue and no visible impurities on the glass surface. The dried FTO glass was then placed in an ultraviolet ozone treatment device for surface treatment. After treatment, it was quickly transferred to the sputtering chamber of a magnetron sputtering device. Argon and oxygen were continuously introduced into the sputtering chamber, and the argon and oxygen fluxes were kept constant. The magnetron sputtering program was started for sputtering treatment to form a 20 nm thick NiO layer on the FTO glass surface. x The layer, after sputtering, will contain NiO. x The substrate of the layer is transferred to the heating equipment and calcined at 400℃ in an air atmosphere for 10 hours. After calcination, the heating equipment is turned off and the substrate is allowed to cool naturally to room temperature. After cooling, the substrate is cut and then placed in a plasma cleaning equipment for cleaning for 40 seconds to complete the pretreatment of the substrate.

[0136] (1.2) Prepare an ethanol solution of DCz-4P ([2-(3,3'-dicarbazole-9-yl)butyl]bisphosphoric acid), precisely adjust the solution concentration to 0.5 mg / mL, filter the prepared DCz-4P ethanol solution through a 0.22 μm polytetrafluoroethylene filter, and transfer it to the sample stage of the spin coater. Fix the pretreated substrate in the center of the sample stage of the spin coater, and spin coat the filtered DCz-4P ethanol solution onto the substrate surface at a speed of 3000 rpm for 30 s. After spin coating, immediately transfer the substrate to the heating device and set the temperature. The substrate was heated to 100℃ for 10 minutes. Then, a PEACI (2-phenylethylamine hydrochloride) isopropanol solution was prepared, with the concentration precisely adjusted to 1 mg / mL. This PEACI isopropanol solution was then filtered through a 0.22 μm polytetrafluoroethylene filter. After filtration, the substrate with the DCz-4P functional layer was again fixed in the center of the spin coater stage. The filtered PEACI isopropanol solution was spin-coated onto the substrate surface at 5000 rpm for 30 seconds. No annealing was performed after spin-coating, resulting in FTO / NiO. x / SAM composite substrate, all spin coating operations are completed on the same spin coater, and the substrate is always kept fixed in the center of the sample stage;

[0137] (2) Preparation of core solution: Weigh out a certain amount of CsI, FAI, MACl, and PbI2 in sequence (the weighing amounts of CsI, FAI, MACl, and PbI2 are 18.18 mg, 204.64 mg, 14.17 mg, and 645.41 mg, respectively), and add 0.2 mol% Tween-80. Slowly add all the raw materials together to a mixed solvent of DMF and DMSO with a volume ratio of 8:2, and stir thoroughly to prepare a ternary perovskite precursor solution with a concentration of 1.4 M (the total molar concentration of all substances CsI, FAI, MACl, and PbI2 in the solution is 1.4 M). Place the brown glass sample bottle containing the ternary perovskite precursor solution in an ultrasonic device for continuous ultrasonic treatment. After ultrasonic treatment, filter the ternary perovskite precursor solution through a 0.22 μm polytetrafluoroethylene filter. After filtration, immediately seal the sample bottle to prevent the solution from deteriorating or changing its composition due to contact with air.

[0138] (3) Initial thin film preparation: FTO / NiO xThe SAM composite substrate was placed in a nitrogen glove box for settling. After settling, a quantitative amount of filtered ternary perovskite precursor solution (50 μL) was slowly aspirated with a pipette and added dropwise to the center of the composite substrate, ensuring that the solution could spread naturally and evenly on the substrate surface. The substrate with the added precursor solution was fixed in the center of the spin coater sample stage, and a one-step anti-solvent method was used for spin coating. First, the spin coating acceleration of the spin coater was set to a low speed of 1000 rpm for 10 seconds, and then the speed was quickly adjusted to 5000 rpm for 30 seconds. In the 5th second of the 5000 rpm high-speed spin coating stage, 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface as an anti-solvent with a pipette. After the spin coating operation was completed, the substrate was immediately removed from the spin coater sample stage and transferred to a heating device. The temperature was set to 110℃ and heated for 25 minutes. After heating, the heating device was turned off, and the substrate was allowed to cool naturally to room temperature to obtain the perovskite film.

[0139] pass Figures 1-3 It can be seen that the passivation treatment with 4-F-Phe-OEt significantly reduces the lead iodide content on the surface of the perovskite film. Figure 1 The residual lead iodide on the thin film surface can affect the performance of battery devices. After passivation treatment, the surface roughness of the thin film is greatly improved. A low RMS indicates that the thin film surface is smoother, which can improve the contact between the perovskite interface and the transport interface layer and improve the carrier extraction efficiency. Figure 2 XRD shows a reduction in the lead iodide peak (around 13.5°), which is consistent with SEM. XRD also shows that the characteristic peaks of perovskite are enhanced after passivation, such as the (100) and (110) crystal planes. This enhancement of crystal structure is beneficial to the improvement of battery device efficiency.

[0140] pass Figure 7 The 300s steady-state output indicates that the battery device, after passivation with 4-F-Phe-OEt, has a low defect state density and good interfacial contact between the perovskite layer and the transport layer. This is because steady-state output reflects the stability and reliability of the battery device under continuous illumination. High defect density in the perovskite film can exacerbate carrier recombination, leading to a decrease in steady-state output and lower efficiency. Figures 8-9It can be seen that the film exhibits good stability after passivation with 4-F-Phe-OEt. Based on the exposed fluorine-containing functional groups of the 4-F-Phe-OEt molecule, it can form a physical barrier to prevent water and oxygen intrusion. Therefore, in order to prove the stability of the film, long-term stability tests were conducted on the samples. (The enhanced lead iodide peak in the XRD pattern of the unpassivated sample indicates severe film decomposition. However, the peak intensities in the XRD pattern of the film sample after passivation with 4-F-Phe-OEt did not change significantly, indicating that the stability of the perovskite film after passivation was greatly improved. The film decomposition phenomenon present in the unpassivated sample did not occur after passivation.)

[0141] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Examples 1-3 and Comparative Examples 1-7 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system at 5×10⁻⁶ Å). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4 As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), photoelectric conversion efficiency (PCE), and the difference between forward and reverse scan efficiency. The difference between forward and reverse scan efficiency is used to characterize the hysteresis effect of the photoelectric device. The smaller the difference, the fewer the interface defects and the better the carrier transport performance. The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 1.

[0142] Table 1

[0143]

[0144] As shown in Table 1, as the passivator concentration increased from 0.2 mg / mL to 0.6 mg / mL, the Voc, Jsc, and FF of the device all showed a continuous upward trend, and the difference in efficiency between forward and reverse scans continued to narrow. When the passivator concentration reached 0.8 mg / mL, the excessive passivator caused grain boundary aggregation and insulating layer effects, hindering interfacial carrier transport, and all photoelectric parameters of the device declined. Figures 6-7As shown, when the annealing temperature is 95℃, passivation is insufficient, the device defect passivation effect is inadequate, and the photoelectric performance is significantly lower than that of Examples 1-2. Under annealing at 100℃, the passivating agent fully combines with the defect sites, and the stability of the perovskite lattice is further improved. Under annealing at 105℃, slight thermal decomposition of the passivating agent leads to a decrease in the passivation effect, and the device performance slightly declines. This invention uses L-4-fluorophenylalanine ethyl ester hydrochloride passivating agent, which, compared with PDAI2 and PDI passivating agents, significantly improves the open-circuit voltage, fill factor, and photoelectric conversion efficiency of the prepared devices, while greatly reducing the forward and reverse scan hysteresis effects.

[0145] The perovskite films obtained in Examples 1-3, Comparative Examples 1-3, and Comparative Example 7 were tested. The core evaluation indicators were average grain size, average grain boundary width, surface porosity, and PbI2 precipitation ratio. All indicators were quantitatively calculated by combining SEM scan images with professional image analysis software. The test results are shown in Table 2.

[0146] Table 2

[0147]

[0148] Table 2 shows that Comparative Example 7, without passivation treatment, exhibits a small grain size, wide grain boundaries, and numerous pores and PbI2 precipitation on the surface of the perovskite film. When the passivating agent concentration is 0.2 mg / mL and 0.4 mg / mL, the passivation effect on lead vacancies and grain boundary defects on the film surface gradually becomes apparent with increasing concentration. Grain size increases, grain boundaries narrow, and porosity and the proportion of PbI2 precipitation decrease significantly. However, due to insufficient passivating agent, complete coverage of all surface defects cannot be achieved. When the passivating agent concentration is 0.6 mg / mL, the passivating agent molecules fully bind to the defect sites on the film surface, effectively regulating the perovskite crystallization kinetics. Grains achieve directional and uniform growth, with an average size reaching 560 nm, and the grain boundary width narrows to 15 nm. Surface porosity and the proportion of PbI2 precipitation drop to extremely low levels, resulting in a dense film without pinholes or obvious grain boundary gaps. When the passivating agent concentration reaches 0.8 mg / mL, excessive passivating agent agglomerates at grain boundaries, hindering continuous grain growth, leading to decreased grain size, wider grain boundaries, and a decline in morphological performance. At an annealing temperature of 95℃, insufficient heat energy results in inadequate bonding between passivating agent molecules and defect sites, failing to effectively suppress PbI2 precipitation and limiting grain growth. At an annealing temperature of 100℃, moderate heat energy ensures sufficient coordination and bonding between the passivating agent and defect sites, further optimizing the ordered arrangement of the perovskite lattice and achieving optimal morphological performance. When the annealing temperature rises to 105℃, slight thermal decomposition leads to a decrease in the passivation effect of the passivating agent, while abnormal local grain growth occurs, resulting in a slight decline in morphological performance.

[0149] Example 4

[0150] Example 4 is prepared in the same way as Example 1, except that in step (3), the antisolvent is added at the 4th second of the high-speed spin coating stage at 5000 rpm. 240 μL of anhydrous chlorobenzene is precisely added to the substrate surface with a pipette to obtain the initial perovskite film.

[0151] Example 5

[0152] Example 5 is prepared in the same way as Example 1, except that in step (3), the antisolvent is added at the 6th second of the high-speed spin coating stage at 5000 rpm. 240 μL of anhydrous chlorobenzene is precisely added to the substrate surface with a pipette to obtain the initial perovskite film.

[0153] Comparative Example 8

[0154] Comparative Example 8 was prepared in the same way as Example 1, except that in step (3), the antisolvent was added at the 1st second of the high-speed spin coating stage at 5000 rpm. 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface with a pipette to obtain the initial perovskite film.

[0155] Comparative Example 9

[0156] Comparative Example 9 was prepared in the same way as Example 1, except that in step (3), the antisolvent was added at the 10th second of the high-speed spin coating stage at 5000 rpm. 240 μL of anhydrous chlorobenzene was precisely added to the substrate surface with a pipette to obtain the initial perovskite film.

[0157] Comparative Example 10

[0158] The preparation method of Comparative Example 10 is basically the same as that of Example 1, except that in step (3), the amount of ternary perovskite precursor solution added is 45 μL; and the initial perovskite film is obtained.

[0159] Comparative Example 11

[0160] The preparation method of Comparative Example 11 is basically the same as that of Example 1, except that in step (3), the amount of ternary perovskite precursor solution added is 55 μL; and the initial perovskite film is obtained.

[0161] The surface coverage, density, and grain boundary integrity of the initial perovskite films of Examples 1, 4-5, and Comparative Examples 8-11 were observed by scanning electron microscopy, and the results are shown in Table 3.

[0162] Table 3

[0163]

[0164] Table 3 shows that when the drop volume is 45 μL, the solution volume is insufficient and cannot completely cover the entire surface of the composite substrate. Local areas of missed coating appear on the film. These missed areas and insufficient solution volume prevent the formation of a dense structure on the film surface, resulting in obvious porosity. Grain boundaries are broken and discontinuous due to these pores, leading to a poor film morphology. When the drop volume is 50 μL, the solution volume is moderate, uniformly and completely covering the entire substrate surface without missed coating or material accumulation. The surface coverage is excellent. After spin coating and heating, the solution forms a dense film structure without any pores, and the grain boundaries are continuous, regular, and without breaks or gaps, resulting in the best film morphology. When the drop volume is 55 μL, the solution volume is excessive. After spin coating, obvious material accumulation appears at the film edges. Although complete coverage of the substrate surface is achieved, the accumulated areas reduce the film surface density, resulting in slight grain boundary gaps. The grain boundaries at the accumulated edges are deformed and irregular, significantly affecting the film morphology. When antisolvent is added dropwise during spin coating at 5000 rpm for 2 seconds, the timing is too early. At this point, the precursor solution has not yet fully spread on the substrate surface. The addition of antisolvent leads to rapid nucleation of the solution, compressing the grain growth space and causing numerous grain boundary defects, resulting in pinholes and cracks on the film surface. When antisolvent is added dropwise during spin coating at 5000 rpm for 4-6 seconds, the timing is appropriate. At this point, the precursor solution has fully spread on the substrate surface and has not yet begun to crystallize. The antisolvent can fully interact with the precursor solution to achieve controlled crystallization, resulting in a film surface free of pinholes and defects, with continuous and regular grain boundaries, and the best film morphology. When antisolvent is added dropwise during spin coating at 5000 rpm for 10 seconds, the timing is too late. At this point, the precursor solution has already begun to initially self-crystallize, and the antisolvent cannot completely expel the perovskite solvent, resulting in solvent residue at the bottom interface, snowflake-like white spots on the back of the film, and obvious defects in the film morphology.

[0165] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Examples 4-5 and Comparative Examples 8-11 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system at 5 × 10⁻⁶ Å). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), photoelectric conversion efficiency (PCE), and the difference in efficiency between forward and reverse scans. The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 4.

[0166] Table 4

[0167]

[0168] Comparative Example 12

[0169] Comparative Example 12 was prepared in the same way as Example 1, except that in step (4), the amount of passivation solution added was 35 μL; a perovskite film was obtained.

[0170] Comparative Example 13

[0171] Comparative Example 13 was prepared in the same way as Example 1, except that in step (4), the amount of passivation solution added was 45 μL; a perovskite film was obtained.

[0172] Comparative Example 14

[0173] Comparative Example 14 was prepared in the same way as Example 1, except that in step (4), the passivation solution was spin-coated onto the surface of the initial perovskite film at a speed of 4000 rpm to obtain the perovskite film.

[0174] Comparative Example 15

[0175] Comparative Example 15 was prepared in the same way as Example 1, except that in step (4), the passivation solution was spin-coated onto the surface of the initial perovskite film at a speed of 6000 rpm to obtain the perovskite film.

[0176] The uniformity of passivation solution coverage, uniformity of passivation solution film thickness, and surface integrity of perovskite films were tested for Examples 1 and Comparative Examples 12-15. The test results are shown in Table 5.

[0177] Table 5

[0178]

[0179] Table 5 shows that when the drop volume is 35 μL, the solution volume is insufficient, and the initial perovskite film cannot be completely covered after spin coating, resulting in some uncovered areas. Due to the small solution volume, there is no scouring or scratching damage to the initial film surface during spin coating. The uncovered areas lead to significant differences in the thickness of the passivation liquid film, resulting in uneven thickness. When the drop volume is 40 μL, the solution volume is moderate, which can uniformly and completely cover the entire surface of the initial film, with no uncovered areas or material accumulation. The coverage is uniform, and there is no damage to the initial film surface during spin coating. The resulting passivation liquid film has a consistent thickness without any unevenness. When the drop volume is 45 μL, the solution volume is excessive, and material accumulation occurs at the edges of the film after spin coating. Excessive solution will have a slight scouring effect on the initial film surface during spin coating, resulting in tiny scratches on the film surface. The liquid film thickness in the material accumulation area is much higher than in other areas, resulting in uneven liquid film thickness.

[0180] When the spin coating speed is 4000 rpm, the speed is too slow, resulting in uneven spreading of the passivation solution on the initial film surface, leading to localized accumulation and thinning. This uneven spreading directly results in significant differences in the thickness of the passivation film. At a spin coating speed of 5000 rpm, the speed is moderate, allowing the passivation solution to spread quickly and evenly on the initial film surface without accumulation or thinning areas. The spin coater operates smoothly, causing no damage to the initial film surface, and the resulting passivation film has a uniform thickness. At a spin coating speed of 6000 rpm, the acceleration is too rapid. During spreading, the solution experiences slight swishing, causing the solution at the film edges to be easily ejected, resulting in a thinner film at the edges. Excessive acceleration also causes slight vibrations in the spin coater, which, when transmitted to the film surface, can cause minor surface damage.

[0181] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Comparative Examples 12-15 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system, at 5 × 10⁻⁶ ℃). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4 As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), photoelectric conversion efficiency (PCE), and the difference in efficiency between forward and reverse scans. The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 6.

[0182] Table 6

[0183]

[0184] Comparative Example 16

[0185] Comparative Example 16 was prepared in the same way as Example 1, except that in step (1), the concentration of the ethanol solution of DCz-4P was 0.25 mg / mL; and finally, a perovskite film was obtained.

[0186] Comparative Example 17

[0187] Comparative Example 17 was prepared in the same way as Example 1, except that in step (1), the concentration of the ethanol solution of DCz-4P was 0.75 mg / mL; and finally, a perovskite film was obtained.

[0188] Comparative Example 18

[0189] Comparative Example 18 was prepared in the same way as Example 1, except that in step (1), the concentration of the ethanol solution of DCz-4P was 1 mg / mL; and finally, a perovskite film was obtained.

[0190] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Comparative Examples 16-18 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system at 5 × 10⁻⁶ ℃). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4 As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 7.

[0191] Table 7

[0192]

[0193] Comparative Example 19

[0194] Comparative Example 19 was prepared in the same way as Example 1, except that in step (1), the concentration of the isopropanol solution of PEACI was 0.5 mg / mL; and finally, a perovskite film was obtained.

[0195] Comparative Example 20

[0196] Comparative Example 20 was prepared in the same way as Example 1, except that in step (1), the concentration of the isopropanol solution of PEACI was 1.5 mg / mL; and finally, a perovskite film was obtained.

[0197] Comparative Example 21

[0198] Comparative Example 21 was prepared in the same way as Example 1, except that in step (1), the concentration of the isopropanol solution of PEACI was 2.0 mg / mL; and finally, a perovskite film was obtained.

[0199] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Comparative Examples 19-21 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system, at 5 × 10⁻⁶ ℃). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4 As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 8.

[0200] Table 8

[0201]

[0202] Example 6

[0203] Example 6 is prepared in the same way as Example 1. The only difference is that in step (5), after the passivation solution spin coating operation is completed, the perovskite film is quickly transferred from the sample stage of the spin coater to the heating device in 20s; finally, the perovskite film is obtained.

[0204] Comparative Example 22

[0205] Comparative Example 22 is prepared in the same way as Example 1, except that in step (5), after the passivation solution spin coating operation is completed, the perovskite film is quickly transferred from the spin coater sample stage to the heating device in 60s; finally, the perovskite film is obtained.

[0206] Complete perovskite solar cells were fabricated based on the perovskite films obtained in Example 6 and Comparative Example 22 (the specific fabrication process involved: vacuum evaporation treatment of the perovskite film surface using a vacuum evaporation system at 5 × 10⁻⁶ Å). -4 A 20 nm thick C layer was deposited using a thermal evaporation method at a rate of 0.1 Å / s under a vacuum of Pa. 60 And a 6nm thick BCP buffer layer, and finally an 80nm thick Cu thin film electrode material deposited at a rate of 1Å / s. The structure of the perovskite solar cell is as follows: Figure 4 As shown in (a), the photoelectric performance of the obtained perovskite solar cells was tested (test conditions: AM 1.5G, one standard light intensity, starting voltage 1.2V, ending voltage -0.1V, scan step size 0.03V), including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). The test data are the average values ​​of 5 parallel cell devices in the same group, and the test results are shown in Table 9.

[0207] Table 9

[0208]

[0209] Table 10 shows the time-dependent photoluminescence data of the perovskite thin films prepared in Example 1 and Comparative Example 7.

[0210]

[0211] Time-resolved photoluminescence (TRPL) images, such as Figure 15 As shown in Table 10, τ1 represents nonradiative recombination related to film defects, and τ2 reflects radiative recombination. As can be seen from Table 10, compared with the unpassivated perovskite film, the attenuation portion τ2 increased from the initial 255.52 ns to 617.44 ns. This indicates the extension of carrier lifetime caused by defect passivation at the perovskite interface. At the same time, the increase in the average fluorescence lifetime of the passivated film (606.87 ns) compared with the fluorescence lifetime of the initial film (unpassivated film) (243.53 ns) also proves the reduction of defect density inside the film.

Claims

1. A method for preparing a perovskite thin film using L-4-fluorophenylalanine ethyl ester hydrochloride as a passivating agent, characterized in that, Includes the following steps: (1) Preparation of composite substrate: FTO glass was first ultrasonically cleaned and rinsed with ethanol, then treated with ultraviolet ozone, and then NiO was deposited by magnetron sputtering. x The FTO glass was first layered and then subjected to high-temperature calcination and plasma treatment. Finally, an ethanol solution of DCz-4P and an isopropanol solution of PEACI were sequentially spin-coated onto the FTO glass to obtain FTO / NiO. x / SAM composite substrate; (2) Under light-protected conditions, L-4-fluorophenylalanine ethyl ester hydrochloride was added to a mixed solvent of isopropanol and chlorobenzene to prepare a passivation solution of 0.4~0.6 mg / mL. After ultrasonic dissolution, the solution was filtered. CsI, FAI, MACl, PbI2 and Tween-80 were added to a mixed solvent of DMF and DMSO to prepare a 1.4 M ternary perovskite precursor solution. After ultrasonic treatment, the solution was filtered. (3) The ternary perovskite precursor solution was dropped onto the center of the substrate and spin-coated using a one-step anti-solvent method. That is, spin-coating was first done at a speed of 1000~1200 rpm for 10~12s, and then spin-coated at a speed of 5000~5500 rpm for 30~32s. During the 4~6s of this stage, chlorobenzene was dropped. After spin-coating was completed, the film was heated at 100~110℃ for 25~26min to obtain the initial perovskite film. (4) The passivation solution is dropped onto the center of the cooled initial perovskite film and spin-coated at a speed of 5000~5500 rpm. The perovskite film with the passivation solution spin-coated is transferred to 95~105℃ for 5~6 min in an inert atmosphere within 20~30 s to obtain the perovskite film with interface passivation treatment.

2. The method of claim 1, wherein: In step (1), the ultrasonic cleaning time is 10-15 minutes, and the ethanol rinsing is performed 3-5 times.

3. The method for preparing perovskite thin films according to claim 1, characterized in that: In step (1), the NiO x The thickness of the layer is 20-25 nm; the temperature of the high-temperature calcination is 400-500 °C, and the calcination time is 10-12 h. 4.The method of claim 1, wherein: In step (1), the concentration of the ethanol solution of DCz-4P is 0.5~0.6 mg / mL, and the concentration of the isopropanol solution of PEACI is 1.0~1.2 mg / mL.

5. The method for preparing perovskite thin films according to claim 4, characterized in that: The ethanol solution of DCz-4P was spin-coated at 3000~3500 rpm for 30~40 s and then heated at 100~150℃ for 10~15 min. The isopropanol solution of PEACI was spin-coated at 5000~6000 rpm for 30~40 s and then no annealing was performed. 6.The method of claim 1, wherein: In step (2), the volume ratio of isopropanol to chlorobenzene in the mixed solvent is 1:1; the volume ratio of DMF to DMSO in the mixed solvent is 8:

2. 7.The method of claim 1, wherein: In step (2), the filtration process refers to filtration through a 0.22μm polytetrafluoroethylene filter. 8.The method of claim 1, wherein: In step (2), the mass ratio of CsI, FAI, MACl, and PbI2 is 18.18:204.64:14.17:645.

41. 9.The method of claim 1, wherein: In step (3), the amount of the ternary perovskite precursor solution added is 48~50 μL; the chlorobenzene is anhydrous chlorobenzene, and the amount of chlorobenzene added is 240~250 μL.

10. The method for preparing perovskite thin films according to claim 1, characterized in that: In step (4), the amount of passivation solution added is 38~40μL.

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