A method for preparing a perovskite thin film by vapor deposition

Abstract

The application discloses a preparation method of a perovskite film by vapor deposition. The perovskite film is prepared by continuously evaporating a lead iodide film and an organic amine salt film to obtain a composite film; the composite film is subjected to humidity treatment to obtain a fully diffused perovskite precursor film; and the perovskite precursor film is subjected to annealing treatment to obtain the perovskite film by vapor deposition. By changing the composition and thickness of the composite film, the humidity of the treatment and the annealing temperature, a uniform and high-quality perovskite film is formed, and the photoelectric properties of the perovskite film are improved. The preparation method is not only suitable for a perovskite solar cell with a normal / inverse structure, but also suitable for a photoelectric device with the perovskite film as an active layer, such as a detector, a light-emitting diode and the like.

Description

Technical Field

[0001] This invention relates to the field of perovskite thin film preparation technology, and more particularly to a method for preparing perovskite thin films by vapor deposition. Background Technology

[0002] Solution processing and vapor deposition are two important methods for preparing perovskite thin films. Currently, most researchers in academia use solution-based spin-coating or blade coating processes to develop high-efficiency perovskite solar cells [Science Advances, 2021, 372(6548): 1327-1332.]. However, due to the significant differences between small-area and large-area crystallization processes, the high-efficiency perovskite solar cell processes explored in the laboratory stage cannot be directly scaled up to prepare standard perovskite modules. In addition, solution-based processes usually use toxic solvents such as N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to dissolve perovskite, which is very harmful to human health and the environment, and also increases the cost of subsequent treatment of toxic waste liquids [Materials Today Advances, 2022, 16: 100277.].

[0003] Vapor deposition (VCD) is a mature semiconductor fabrication technology that has been proven to have large-scale fabrication capabilities. The process technology for high-efficiency small-area perovskite solar cells using VCD can be directly transferred to large-area modules without much adjustment. Simultaneously, VCD directly avoids the use of organic solvents, eliminating the cost of solvent waste treatment during production. The vapor deposition method can be mainly divided into co-evaporation and continuous vapor deposition. Continuous vapor deposition avoids crosstalk caused by the evaporation of multiple components. Currently, although the PCE of perovskite devices fabricated using continuous vapor deposition has exceeded 24% [Science Advances, 2022, 8(28):7422-7429.], its fabrication time is relatively long, which is not conducive to industrial production.

[0004] Therefore, existing vapor deposition technology still needs further improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing perovskite thin films by vapor deposition, which aims to solve the problem of long time consumption in the existing continuous vapor deposition of perovskite thin films.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] A method for preparing a perovskite thin film by vapor deposition, comprising:

[0008] Lead iodide or lead bromide is deposited onto a substrate under vacuum conditions to form an inorganic thin film on the surface of the substrate.

[0009] An organic amine salt is deposited onto the surface of the inorganic film to form an organic film, thereby obtaining a composite film; wherein the organic amine is selected from any one of formamidin hydroiodate, phenylethylamine hydroiodate, butylamine hydroiodate, and oleylamine hydroiodate.

[0010] The composite film is subjected to humidity treatment to obtain a perovskite precursor film;

[0011] The perovskite precursor film is annealed to obtain the vapor-deposited perovskite film.

[0012] Optionally, the lead iodide contains cesium iodide (0-100 mg) and / or lead chloride (0-300 mg).

[0013] Specifically, cesium iodide can be used to modulate the tolerance factor of the perovskite structure, thereby improving the phase stability of the film. Lead chloride can be used to control the crystallization process of the composite film, producing perovskite films of higher quality and improving device performance.

[0014] Optionally, the thickness of the inorganic thin film is 100-350 nm, such as 100 nm to 150 nm, 150 nm to 200 nm, 200 nm to 250 nm, 250 nm to 300 nm, or 300 nm to 350 nm; the evaporation rate of the inorganic thin film is... like to to to to

[0015] Specifically, using a higher evaporation rate can significantly reduce the preparation time; adjusting the appropriate thickness is beneficial for the full reaction of the subsequent organic amine salts and is the key to controlling the film quality.

[0016] Optionally, the thickness of the organic thin film is 150-400 nm, such as 150 nm to 200 nm, 200 nm to 250 nm, 250 nm to 300 nm, 300 nm to 350 nm, or 350 nm to 400 nm; the evaporation rate of the organic thin film is...

[0017] Specifically, using a higher evaporation rate can significantly reduce the preparation time; controlling the appropriate thickness is key to generating high-quality perovskite films with stoichiometry.

[0018] Optionally, the thickness of the organic thin film is positively correlated with the thickness of the inorganic thin film, satisfying Y = X + N, where Y is the thickness of the organic thin film, X is the thickness of the inorganic thin film, and N ranges from 20 to 50 nm.

[0019] Specifically, as the thickness of the deposited inorganic film gradually increases, the required thickness of the organic film to form an isostometric perovskite film also needs to increase accordingly. If the organic film thickness is insufficient, a film with a high inorganic content will be formed, which is detrimental to device performance. If the organic film thickness is too large, the final film will contain low-dimensional components, which is also detrimental to device performance.

[0020] Optionally, the relative humidity of the humidity treatment is 70-100%, such as 70%-80%, 80% to 90%, or 90% to 100%; the treatment time is 1-10 minutes.

[0021] Specifically, when the humidity is below 70%, the required processing time increases rapidly. When the processing time is too long at 70-100% humidity, obvious decomposition will occur on the surface of the composite film.

[0022] Optionally, the relative humidity of the annealing environment for the annealing treatment is 40-70%, such as 40% to 50%, 50% to 60%, or 60% to 70%; and the annealing temperature is 160-180℃, such as 160℃ to 170℃ or 170℃ to 180℃.

[0023] Specifically, annealing at a certain humidity level is beneficial to the crystallinity of the film. When the humidity is too low, the crystallization-aiding effect of water molecules in the film is not significant; when the humidity is too high, the water molecules in the film will have a destructive effect. Similarly, if the annealing temperature is too low, it will affect the crystallization process; if it is too high, it will lead to decomposition.

[0024] A vapor-deposited perovskite thin film, wherein the perovskite thin film is prepared by the vapor-deposited perovskite thin film preparation method described above.

[0025] A vapor-deposited perovskite solar cell includes a perovskite layer, wherein the perovskite layer is the vapor-deposited perovskite thin film described above.

[0026] Beneficial Effects: Compared with existing technologies, the vapor-deposited perovskite thin film preparation method of the present invention, through continuous vapor deposition of inorganic and organic components followed by humidity treatment and annealing, effectively improves the crystallinity of the perovskite thin film. When used in perovskite solar energy devices, it can significantly improve device performance. This preparation method is not only applicable to the preparation of perovskite solar cells with positive / negative structures, but also to optoelectronic devices with perovskite thin films as the active layer, such as detectors and light-emitting diodes. Furthermore, the preparation process does not involve harmful solvents, is environmentally friendly, and has a fast deposition rate and short processing time. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the process for preparing perovskite thin films by vapor deposition.

[0028] Figure 2 This is a structural diagram of a vapor-deposited perovskite solar cell.

[0029] Figure 3 The image shows the XRD pattern of the composite film with and without humidity treatment.

[0030] Figure 4 This is a SEM cross-sectional view of the composite film with and without humidity treatment.

[0031] Figure 5 The image shows the XRD pattern of the composite film after annealing with and without moisture treatment.

[0032] Figure 6 This is a SEM cross-sectional view of the composite film after annealing with and without moisture treatment.

[0033] Figure 7 JV test curves of perovskite solar cells with formal structure prepared by annealing composite thin films with and without moisture treatment.

[0034] Figure 8 Stability test results for a formally structured perovskite solar cell prepared after annealing of a composite thin film with and without moisture treatment. Detailed Implementation

[0035] This invention provides a method for preparing perovskite thin films by vapor deposition. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0036] To address the issues of poor crystallinity in existing vapor-deposited perovskite films and the tendency for non-radiative recombination to occur when used in perovskite solar cells, resulting in low photoelectric conversion efficiency.

[0037] This embodiment provides a method for preparing perovskite thin films by vapor deposition, such as... Figure 1 As shown, the method for preparing the vapor-deposited perovskite thin film includes:

[0038] S10. Inorganic thin films are prepared by vapor deposition.

[0039] Specifically, under vacuum conditions, lead iodide doped with partial amounts of cesium iodide, lead chloride, and lead bromide is used as the raw material, and... The method involves evaporating inorganic thin films with a thickness of 100-350 nm onto a substrate at a specific rate. The evaporation equipment and specific operations involved are commonly used in this field and will not be elaborated upon here.

[0040] S20. Evaporate the organic components and use a thermal evaporation method to deposit the organic amine salt onto the surface of the inorganic film to form an organic film, thereby obtaining a composite film.

[0041] Specifically, a certain amount of formamidinium hydroiodate or methylamine hydroiodate is weighed into a quartz crucible. The organic amine salt is thermally evaporated by heating the quartz crucible and deposited onto an inorganic film to form an organic film, thus obtaining a composite film. The evaporation temperature of the organic amine salt is 180-230℃, and the evaporation rate is... The thickness ranges from 150 to 400 nm. By controlling the evaporation thickness of the organic amine salt, the component ratio of the thin film can be adjusted, thereby improving the quality of the film after deposition. For example, when the thickness of the inorganic thin film is 200 nm, the corresponding organic thin film needs to be 220 nm; when the thickness of the inorganic thin film is 350 nm, the corresponding organic thin film needs to be 400 nm.

[0042] S30. The composite film is subjected to humidity treatment to obtain the perovskite precursor film.

[0043] Specifically, the composite film prepared in step S20 is placed in a closed environment with controllable humidity for treatment. Typically, the humidity is selected as 70-100%, and the treatment time is 1-10 minutes to obtain the perovskite precursor film.

[0044] S40. Anneal the perovskite precursor film to obtain the vapor-deposited perovskite precursor film.

[0045] Specifically, the perovskite precursor film prepared in step S30 is placed on a hot plate in an air environment for annealing. For example, the perovskite film precursor is placed on a hot plate with a relative humidity of 40-70% and a temperature of 160-180℃ for annealing for 30-40 minutes to obtain a vapor-deposited perovskite film.

[0046] In this embodiment, the morphology and crystallinity of the perovskite thin film can be effectively controlled by a process that combines the vapor deposition of inorganic and organic components with humidity treatment to assist the diffusion crystal growth of organic amine salts. When the composite film is exposed to humidity, the organic components on the surface diffuse to the bottom of the inorganic components under the action of water molecules, forming a composite film with uniformly mixed components. During the annealing process, due to the pre-diffusion effect of the organic components, the heat energy only needs to cause the inorganic and organic components to react with each other, without further promoting the diffusion effect. Therefore, the prepared vapor-deposited perovskite thin film has good morphology and crystallinity, and when used in solar energy devices, it can produce high-performance devices.

[0047] Based on the same inventive concept, the present invention also provides an application of the vapor-deposited perovskite thin film as described above in perovskite solar cells.

[0048] In one implementation of this embodiment, the perovskite solar cell includes: a glass substrate, a transparent electrode disposed on the glass substrate, a hole transport layer disposed on the transparent electrode, a perovskite layer disposed on the hole transport layer, an electron transport layer disposed on the perovskite layer, and a metal counter electrode disposed on the electron transport layer, wherein the perovskite layer of the perovskite solar cell is the aforementioned vapor-deposited perovskite thin film.

[0049] The following specific preparation examples will further explain and illustrate the preparation method of the vapor-deposited perovskite thin film provided by the present invention.

[0050] Example 1

[0051] (1) Cleaning the ITO glass substrate. The ITO glass substrate was ultrasonically cleaned for 30 minutes each with sodium dodecylbenzenesulfonate, deionized water, and isopropanol. After cleaning, it was dried on a hot table. Then, the glass substrate was placed in an ultraviolet ozone cleaner for ozone treatment for 30 minutes.

[0052] (2) Preparation of an electron transport layer on an ITO glass substrate. The specific method is as follows: SnO2 (15% by mass aqueous colloidal dispersion) and deionized water are mixed at a volume ratio of 1:3 and then uniformly dispersed using a vortex mixer. 45 μL of the dispersed SnO2 aqueous sol is spin-coated onto the ITO glass substrate at 3000 rpm for 30 s. Finally, it is annealed on a hot plate at 150℃ for 30 min.

[0053] (3) Preparation of the vapor-deposited perovskite active layer. First, weigh 860 mg of PbI₂, 140 mg of PbCl₂, and 60 mg of CsI, grind them thoroughly, and use them as inorganic evaporation materials. Weigh 700 mg of FAI and place it in a crucible as organic evaporation material. Under vacuum... ＜ 10 -4 Pa below, with An inorganic thin film with a thickness of 350 nm was deposited at a high rate. Then, an organic thin film with a thickness of 400 nm was deposited, resulting in an inorganic / organic composite film. The resulting inorganic / organic composite film was treated at a relative humidity of 90% for 1 min to allow the organic amine salt to fully diffuse into the bottom inorganic layer and transform into a perovskite precursor film. Next, the perovskite precursor film was annealed at 170°C for 30 min on a hot stage with an ambient humidity of 50% to obtain a vapor-deposited perovskite film.

[0054] (4) Preparation of a hole transport layer on a perovskite film. 72.3 mg of 2,2',7',7-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD) was dissolved in 1 mL of chlorobenzene, followed by the sequential addition of 17.5 μL of an acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL) and 28.8 μL of 4-tert-butylpyridine. 15 μL of the prepared Spiro-OMeTAD solution was spin-coated at 3000 rpm for 30 s.

[0055] (5) Evaporation deposition of metal electrodes. This is achieved through an evaporation deposition process... A 40 nm thick metal electrode was deposited on the Spiro-OMeTAD thin film at a specific rate. The fabrication process is as follows: Figure 1 As shown. The final result is as follows. Figure 2 The image shows a formal vapor-deposited perovskite solar cell.

[0056] Example 2

[0057] (1) Cleaning the ITO glass substrate. The ITO glass substrate was ultrasonically cleaned for 30 minutes each with sodium dodecylbenzenesulfonate, deionized water, and isopropanol. After cleaning, it was dried on a hot table. Then, the glass substrate was placed in an ultraviolet ozone cleaner for ozone treatment for 30 minutes.

[0058] (2) Preparation of an electron transport layer on an ITO glass substrate. The specific method is as follows: SnO2 (15% by mass aqueous colloidal dispersion) and deionized water are mixed at a volume ratio of 1:4 and then uniformly dispersed using a vortex mixer. 45 μL of the dispersed SnO2 aqueous sol is spin-coated onto the ITO glass substrate at 3000 rpm for 20 s. Finally, it is annealed on a hot plate at 160℃ for 30 min.

[0059] (3) Preparation of the vapor-deposited perovskite active layer. First, weigh 860 mg of PbI₂, 140 mg of PbCl₂, and 60 mg of CsI, and grind them thoroughly as inorganic evaporation materials. Weigh 700 mg of FAI and place it in a crucible as organic evaporation material. Under a vacuum degree <10... -4 Pa below, with An inorganic thin film with a thickness of 200 nm was deposited at a specific rate. Then, an organic thin film with a thickness of 150 nm was deposited, resulting in an inorganic / organic composite film. The resulting inorganic / organic composite film was then treated at a relative humidity of 70% for 3 minutes to allow the organic amine salt to fully diffuse into the bottom inorganic layer and transform into a perovskite precursor film. Next, the perovskite precursor film was annealed at 160°C for 30 minutes on a hot stage with an ambient humidity of 40% to obtain a vapor-deposited perovskite film.

[0060] (4) Preparation of a hole transport layer on a perovskite film. 72.3 mg of 2,2',7',7-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD) was dissolved in 1 mL of chlorobenzene, followed by the sequential addition of 17.5 μL of an acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL) and 28.8 μL of 4-tert-butylpyridine. 30 μL of the prepared Spiro-OMeTAD solution was spin-coated at 3000 rpm for 30 s.

[0061] (5) Evaporation deposition of metal electrodes. This is achieved through an evaporation deposition process... A 50 nm thick metal electrode was deposited on the Spiro-OMeTAD thin film at a certain rate.

[0062] Example 3

[0063] (1) Cleaning the ITO glass substrate. The ITO glass substrate was ultrasonically cleaned for 30 minutes each with sodium dodecylbenzenesulfonate, deionized water, and isopropanol. After cleaning, it was dried on a hot table. Then, the glass substrate was placed in an ultraviolet ozone cleaner for ozone treatment for 30 minutes.

[0064] (2) Preparation of an electron transport layer on an ITO glass substrate. The specific method is as follows: SnO2 (15% by mass aqueous colloidal dispersion) and deionized water are mixed at a volume ratio of 1:5 and then uniformly dispersed using a vortex mixer. 45 μL of the dispersed SnO2 aqueous sol is spin-coated onto the ITO glass substrate at 4000 rpm for 30 s. Finally, it is annealed on a hot plate at 160℃ for 30 min.

[0065] (3) Preparation of the vapor-deposited perovskite active layer. First, weigh 860 mg of PbI₂, 140 mg of PbCl₂, and 60 mg of CsI, and grind them thoroughly as inorganic evaporation materials. Weigh 700 mg of FAI and place it in a crucible as organic evaporation material. Under a vacuum degree <10... -4 Pa below, with An inorganic thin film with a thickness of 100 nm was deposited at a specific rate. Then, an organic thin film with a thickness of 150 nm was deposited, resulting in an inorganic / organic composite film. The resulting inorganic / organic composite film was then treated at 100% relative humidity for 10 min to allow the organic amine salt to fully diffuse into the bottom inorganic layer and transform into a perovskite precursor film. Next, the perovskite precursor film was annealed at 160°C for 40 min on a hot stage with 50% ambient humidity to obtain a vapor-deposited perovskite film.

[0066] (4) Preparation of a hole transport layer on a perovskite film. 72.3 mg of 2,2',7',7-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD) was dissolved in 1 mL of chlorobenzene, followed by the sequential addition of 17.5 μL of an acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL) and 28.8 μL of 4-tert-butylpyridine. 30 μL of the prepared Spiro-OMeTAD solution was spin-coated at 3000 rpm for 20 s.

[0067] (5) Evaporation deposition of metal electrodes. This is achieved through an evaporation deposition process... A 60 nm thick metal electrode was deposited on the Spiro-OMeTAD thin film at a certain rate.

[0068] Example 4

[0069] (1) Cleaning the ITO glass substrate. The ITO glass substrate was ultrasonically cleaned for 30 minutes each with sodium dodecylbenzenesulfonate, deionized water, and isopropanol. After cleaning, it was dried on a hot table. Then, the glass substrate was placed in an ultraviolet ozone cleaner for ozone treatment for 30 minutes.

[0070] (2) Preparation of a hole transport layer on an ITO glass substrate. The specific method is as follows: 2-(3,6-dimethoxy-9H-carbazole-9-yl)ethylphosphonic acid (MeO-2PACz) was first dissolved in ethanol to prepare a solution with a concentration of 0.4 mg / mL, and then shaken on a shaker for 10 min. Next, it was spin-coated onto the ITO conductive substrate at 5000 rpm for 30 s. Finally, it was annealed at 100℃ for 10 min to obtain the hole transport layer.

[0071] (3) Preparation of the vapor-deposited perovskite active layer. First, weigh 860 mg of PbI₂, 140 mg of PbCl₂, and 60 mg of CsI, and grind them thoroughly as inorganic evaporation materials. Weigh 700 mg of FAI and place it in a crucible as organic evaporation material. Under a vacuum degree <10... -4 Pa below, with An inorganic thin film with a thickness of 350 nm was deposited at a high rate. Then, an organic thin film with a thickness of 400 nm was deposited, resulting in an inorganic / organic composite film. The resulting inorganic / organic composite film was then treated at 100% relative humidity for 3 minutes to allow the organic amine salt to fully diffuse into the bottom inorganic layer and transform into a perovskite precursor film. Next, the perovskite precursor film was annealed at 180°C for 30 minutes on a hot stage with 70% ambient humidity to obtain a vapor-deposited perovskite film.

[0072] (4) Preparation of electron transport layer and metal electrode. First, [6,6]-phenyl C61 butyrate methyl ester (PCBM) was dissolved in chlorobenzene to prepare a solution with a concentration of 10 mg / mL, and then shaken on a shaker for 5-10 min. Then, it was spin-coated onto a perovskite film at 5000 rpm for 30 s. Finally, a 10 nm fullerene (C60) layer, a 4 nm 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) layer, and a 90 nm metal electrode were sequentially deposited to obtain a perovskite solar cell with an inverse structure.

[0073] Example 5

[0074] By comparing and verifying the conditions listed in the table below, it can be seen that the preparation method provided by this invention has a shorter preparation time and is more efficient.

[0075]

[0076] The composite film with and without humidity treatment obtained in Example 1 was tested, and its XRD pattern is shown below. Figure 3 As shown, the SEM cross-section is as follows Figure 4 As shown, the composite film without humidity treatment exhibits delamination, forming only a small amount of perovskite. In contrast, the composite film treated with humidity allows the surface organic layer to diffuse into the bottom, forming a yellow δ-phase perovskite; this demonstrates that humidity treatment promotes the diffusion and reaction of the organic layer, forming a perovskite precursor film. XRD and SEM cross-sectional data of the aforementioned precursor film were analyzed after annealing, as shown... Figure 5 and Figure 6 As shown, the film treated with humidity exhibits better crystallinity and complete reaction, while the film without humidity treatment shows incomplete reaction and numerous defects. The formal vapor-deposited perovskite solar cell obtained in Example 1 was tested, and its JV curve is shown below. Figure 7 This demonstrates that devices fabricated from moisture-treated thin films exhibit higher performance and better stability, such as... Figure 8 As shown.

[0077] In summary, this invention provides a method for preparing a vapor-deposited perovskite thin film. The method includes: preparing an inorganic thin film and an organic thin film using a vapor deposition method to obtain a composite thin film; forming a perovskite precursor film through humidity treatment; and then annealing under a certain humidity to obtain the vapor-deposited perovskite thin film. By changing the thickness ratio of the composite thin film, the humidity treatment time, and the annealing temperature and time, the morphology and crystallinity of the perovskite are effectively controlled, resulting in a uniform vapor-deposited perovskite thin film. This preparation method is applicable not only to perovskite solar cells with positive / negative structures but also to optoelectronic devices using vapor-deposited perovskite thin films as light-absorbing layers. The perovskite thin film prepared using a continuous vapor deposition process possesses industrialization advantages such as solvent-free processing, conformal deposition capability, and large-scale fabrication, providing a new approach for preparing high-efficiency, large-area perovskite / textured silicon tandem solar devices.

[0078] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a perovskite thin film by vapor deposition, characterized in that, include: Lead bromide is deposited onto a substrate under vacuum conditions to form an inorganic thin film on the surface of the substrate. An organic amine salt is deposited onto the surface of the inorganic thin film to form an organic thin film, thus obtaining a composite thin film. The composite film is subjected to humidity treatment to obtain a perovskite precursor film; The perovskite precursor film is annealed to obtain the vapor-deposited perovskite film. The annealing environment for the annealing treatment has a relative humidity of 40-70% and an annealing temperature of 160-180℃. The thickness of the organic film is positively correlated with the thickness of the inorganic film, satisfying Y=X+N, where Y is the thickness of the organic film, X is the thickness of the inorganic film, and N ranges from 20 to 50 nm. The composite film is subjected to humidity treatment to obtain a perovskite precursor film, specifically including: The composite film is subjected to humidity treatment, which causes the organic amine salt in the organic film to diffuse to the bottom of the inorganic film under the action of water molecules, forming a perovskite precursor film with uniformly mixed components. The relative humidity for the humidity treatment is 70-100%, and the treatment time is 1-10 minutes.

2. The method for preparing perovskite thin films by vapor deposition according to claim 1, characterized in that, The inorganic thin film has a thickness of 100-350 nm; the lead bromide deposition rate is 1-10 Å / s.

3. The method for preparing perovskite thin films by vapor deposition according to claim 1, characterized in that, The organic amine is selected from any one of formamidin hydroiodide, phenethylamine hydroiodide, butylamine hydroiodide, and oleylamine hydroiodide.

4. The method for preparing a perovskite thin film by vapor deposition according to claim 3, characterized in that, The thickness of the organic film is 150-400 nm, and the deposition rate of the formamidinium hydroiodate is 3-5 Å / s.

5. A vapor-deposited perovskite thin film, characterized in that, The perovskite thin film was prepared by the method described in any one of claims 1-4.

6. A vapor-deposited perovskite solar cell, comprising a perovskite layer, characterized in that, The perovskite layer is the vapor-deposited perovskite thin film as described in claim 5.

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