Atmosphere post-processing method of perovskite thin film and perovskite solar cell

Abstract

The invention discloses an atmosphere post-processing method of a perovskite thin film and a perovskite solar cell, and belongs to the technical field of solar cells. The atmosphere post-processing method of the perovskite thin film comprises the following steps: S1, preparing a perovskite precursor solution into a perovskite precursor thin film, and carrying out heat treatment on the perovskite precursor thin film to form a perovskite thin film; s2, placing the perovskite thin film in a constant-temperature and constant-humidity atmosphere condition for perovskite thin film recrystallization; and S3, cooling the recrystallized perovskite thin film in a dry environment to room temperature to prepare a perovskite layer. According to the perovskite thin film, due to the recrystallization and defect passivation effects assisted by the constant-temperature and constant-humidity atmosphere, the grain size of the perovskite thin film is increased, the crystallization quality is improved, the grain boundary of perovskite is reduced, the defect density is reduced, a perovskite layer which is uniform in coverage and smooth in surface can be prepared, and then the photoelectric performance of a battery is efficiently improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to an atmosphere post-treatment method for a perovskite film and a perovskite solar cell. Background Art

[0002] In the photovoltaic field, organic-inorganic hybrid perovskite solar cells have developed rapidly due to their low cost, high efficiency, and low-temperature solution preparation. Their photoelectric conversion efficiency has exceeded 26%, which is almost comparable to that of single-crystal silicon solar cells. However, in order to optimize the preparation process, some polymers (such as CN202310318969.2), semiconductors (such as CN201410357437.0) are often added to the preparation process, or some special structures (such as CN202310318969.2) and treatment processes (such as CN202310367393.9) are designed. While greatly increasing the cost, it complicates the process flow, increases the process risk, and reduces the yield. Seeking a method for preparing a high-quality perovskite light-absorbing functional layer with simple process, low cost, good repeatability, and easy industrialization is of great significance for the development of industrialized perovskite solar cells. Summary of the invention

[0003] The main purpose of the present invention is to provide an atmosphere post-treatment method for a perovskite film and a perovskite solar cell, so as to solve the problems of high cost, complex process, high risk, low yield, poor perovskite crystal quality, etc. in the existing perovskite film preparation method, and to improve the stability and photoelectric efficiency of the perovskite solar cell.

[0004] In order to achieve the above object, the present invention provides an atmosphere post-treatment method for a perovskite film, comprising the following steps:

[0005] Step S1, first preparing a perovskite precursor solution into a perovskite precursor film, and then subjecting the perovskite precursor film to heat treatment to form a perovskite film;

[0006] Step S2, placing the perovskite film in a constant temperature and humidity atmosphere to recrystallize the perovskite film;

[0007] Step S3, cooling the recrystallized perovskite film to room temperature in a dry environment to obtain a perovskite layer.

[0008] Furthermore, the constant temperature and humidity conditions are: humidity is 70% to 90%, temperature is 40 to 90° C.; and the atmosphere is water vapor or gas containing water vapor.

[0009] Furthermore, the recrystallization time of the perovskite film is 10 to 120 seconds.

[0010] Furthermore, the perovskite precursors in the perovskite precursor solution are AX and BX 2 A is CH 3 NH 3 + 、HC(=NH)NH 3 + , Cs + , Rb + or K + One or more of, B is Pb 2 + and / or Sn 2 + , X is one or more halogen ions.

[0011] Furthermore, the molar concentration of the perovskite precursor solution is 1.0-1.8 mol / L.

[0012] Furthermore, the heat treatment temperature is 100-150° C. and the time is 10-60 min.

[0013] Furthermore, the thickness of the perovskite film is 400-1000 nm.

[0014] In another aspect of the present invention, a perovskite solar cell is provided, comprising a transparent conductive substrate, an electron transport layer / hole transport layer, a perovskite layer, a hole transport layer / electron transport layer and a metal electrode stacked in sequence from bottom to top, wherein the perovskite layer is prepared by the aforementioned atmosphere post-treatment method of the perovskite film.

[0015] Furthermore, the material of the electron transport layer is tin oxide, zinc oxide, titanium oxide, PCBM or C 60 One or more of the above, wherein the thickness of the electron transport layer is 10 to 50 nm.

[0016] Furthermore, the material of the hole transport layer is one or more of Spiro-OMeTAD, PTAA, NiO, Me-4PACZ or MeO-2PACZ, and the thickness of the hole transport layer is 1 to 200 nm.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The perovskite layer prepared by the atmosphere post-treatment method of the perovskite film of the present invention, thanks to the recrystallization and defect passivation effect assisted by the constant temperature and humidity atmosphere, makes the grain size of the perovskite film larger, improves the crystallization quality, reduces the grain boundaries of the perovskite, reduces the defect density, and can prepare a perovskite layer with uniform coverage and smooth surface, thereby efficiently improving the photoelectric performance of the battery. (2) The atmosphere post-treatment method of the perovskite film of the present invention is low-cost, easy to implement, and very easy to scale up from laboratory-level production to industrial level. (3) The perovskite solar cell provided by the present invention has high efficiency and good stability, and the photoelectric conversion efficiency can be increased from the basic 21% to more than 26%, which greatly improves the photoelectric conversion efficiency of the perovskite solar cell currently prepared by the low-temperature solution method, and has extremely high commercialization and industrialization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural comparison diagram of a perovskite solar cell made by treating a perovskite film with the atmosphere of the present invention and a perovskite solar cell made by treating a perovskite film with no atmosphere post-treatment;

[0019] Figure 2 Surface scanning electron microscope images of the perovskite layers prepared in Example 1-2 and Comparative Example 1-2 of the present invention;

[0020] Among them, the above-mentioned drawings include the following figure marks: 1. transparent conductive substrate; 2. electron / hole transport layer; 3. grain boundary; 4. perovskite layer; 5. hole / electron transport layer; 6. metal electrode. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0022] According to a first aspect of an embodiment of the present invention, there is provided a method for preparing a perovskite film and a solar cell after atmosphere post-treatment, comprising the following steps:

[0023] Step S1, first preparing a perovskite precursor solution into a perovskite precursor film, and then subjecting the perovskite precursor film to heat treatment to form a perovskite film;

[0024] Step S2, placing the perovskite film in a constant temperature and humidity atmosphere to recrystallize the perovskite film;

[0025] Step S3, cooling the recrystallized perovskite film to room temperature in a dry environment to obtain a perovskite layer.

[0026] The atmosphere post-treatment method of the present invention is to prepare the perovskite layer, which is to first heat-treat the perovskite precursor solution into a perovskite film, and then perform a constant temperature and humidity atmosphere post-treatment on the perovskite film to assist the perovskite film to recrystallize, so that the grain size becomes larger, and the crystallization defects are regulated, the grain boundaries of the perovskite are reduced, and the crystallization quality of the perovskite layer is further improved, and a perovskite layer with uniform coverage and a smooth surface can be prepared, thereby efficiently improving the photoelectric performance of the battery. The method for preparing the perovskite layer of the present invention is an improvement measure for the one-step method. Compared with the prior art of treating the precursor by water vapor, the present invention directly acts on the prepared perovskite film, and the treatment time is short, the effect is better, and the method is simpler.

[0027] In order to further improve the crystal quality of the perovskite film, reduce the grain boundaries of the perovskite, and reduce the defect density, in a preferred embodiment of the present invention, the constant temperature and humidity conditions are: humidity is 70% to 90%, for example, including but not limited to 70%, 75%, 78%, 80%, 85%, 88% and 90%; temperature is 40 to 90°C, for example, including but not limited to 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C and 90°C. The atmosphere is water vapor or a gas containing water vapor. When the present invention uses a water vapor atmosphere treatment, ammonia and methylamine gas can be additionally added as a promoter for the recrystallization of the perovskite film to further improve the crystal quality of the perovskite film.

[0028] The present invention specifically selects parameters such as temperature and humidity of the above-mentioned atmosphere treatment in combination with the chemical composition and preparation conditions of the perovskite film to obtain a higher quality perovskite film, which can effectively improve the performance of the perovskite solar cell when applied to the perovskite solar cell.

[0029] In a preferred embodiment of the present invention, the recrystallization time of the perovskite film is 10 to 120 seconds. For example, it may include but is not limited to 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, 110 seconds and 120 seconds. When the recrystallization time of the perovskite film is too short, the crystal quality of the perovskite film and the grain boundaries cannot be effectively improved. When the recrystallization time of the perovskite film is too long, water vapor will enter the interior of the perovskite film, resulting in a decrease in the light stability of the film and a decrease in device performance. Therefore, it is necessary to accurately control the recrystallization time.

[0030] In order to further improve the photoelectric performance of the perovskite film, in some preferred embodiments of the present invention, the perovskite precursor in the perovskite precursor solution is AX and BX 2 A is CH 3 NH 3 + 、HC(=NH)NH3 + , Cs + , Rb + or K + One or more of, B is Pb 2 + and / or Sn 2 + , X is one or more halogen ions; the molar concentration of the perovskite precursor solution is 1.0 to 1.8 mol / L; and the thickness of the perovskite film is 400 to 1000 nm.

[0031] In some optional embodiments of the present invention, the drying environment may be under vacuum conditions, pure inert gas protection conditions such as nitrogen protection, low humidity space conditions created by instruments such as drying cabinets, etc.

[0032] In some optional embodiments of the present invention, the perovskite precursor solution is made into a perovskite precursor film by spin coating-antisolvent method, slit coating or doctor blade coating. For example, when the perovskite precursor film is prepared by spin coating-antisolvent method, the spin coating speed of the perovskite precursor solution is 2000-8000 rpm, and the spin coating time is 20-60 s.

[0033] A second aspect of an embodiment of the present invention provides a perovskite solar cell, such as Figure 1 As shown, it includes a transparent conductive substrate 1, an electron transport layer / hole transport layer 2, a perovskite layer 4, a hole transport layer / electron transport layer 5 and a metal electrode 6 stacked in sequence from bottom to top, and the perovskite layer 4 is prepared by the aforementioned atmosphere post-treatment method of the perovskite film.

[0034] from Figure 1 It can be seen that the interior of the perovskite layer 4 of the perovskite film without atmosphere post-treatment contains more grain boundaries 3, while the grain boundaries 3 inside the perovskite layer 4 can be effectively reduced when the perovskite film is subjected to atmosphere post-treatment.

[0035] In some preferred embodiments of the present invention, the material of the electron transport layer is tin oxide, zinc oxide, titanium oxide, PCBM ([6,6]-phenyl-C61-butyric acid isomethyl ester) or C 60 One or more of the following; the thickness of the hole transport layer is 10 to 50 nm.

[0036] In some preferred embodiments of the present invention, the material of the hole transport layer is one or more of Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), PTAA (polybis(4-phenyl)(2,4,6-trimethylphenyl)amine), NiO, Me-4PACZ ((4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid) or MeO-2PACZ ([2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid); the thickness of the hole transport layer is 1 to 200 nm.

[0037] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0038] Example 1

[0039] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), an electron transport layer (TiO 2 layer), a perovskite layer, a hole transport layer (Spiro-OMeTAD) and a metal electrode (Au), wherein the perovskite layer is prepared by recrystallizing the perovskite film for 10 seconds under a constant temperature and humidity atmosphere (water vapor) with a humidity of 85% and a temperature of 85°C, and the specific preparation method comprises the following steps:

[0040] Step 1: In a clean environment, select FTO conductive glass with a square resistance of 10Ω / sq and a thickness of 1.1mm as a transparent conductive substrate; ultrasonically clean the FTO conductive glass in glass cleaning agent, acetone, and anhydrous ethanol for 30 minutes, and then blow dry with nitrogen; clean the dried glass in an ozone plasma cleaning machine for 30 minutes to remove organic matter on the glass surface and enhance the hydrophilicity of the surface;

[0041] Step 2: Preparation of electron transport layer: 900 μL of titanium tetrachloride was added to 50 mL of frozen ultrapure water, and a mixed solution was obtained after complete melting. The cleaned FTO conductive glass was immersed in the mixed solution, and then placed in a 70°C oven for hydrothermal treatment for 1 h. After the hydrothermal treatment, the FTO conductive glass was taken out, thoroughly washed with ultrapure water and anhydrous ethanol, and then dried with nitrogen, and then placed in a 105°C oven for heat treatment for 1 h to obtain a dense TiO with a thickness of 30 nm. 2 Layer, namely the electron transport layer;

[0042] Step 3: Prepare 1.25 mol / L perovskite precursor solution Cs in an argon glove box. 0.05 FA 0.81 MA 0.14 PbI 2.55 Br0.45 : 8.12 mg CH3NH3I, 86.76 mg HC(=NH)NH 3 I. 9.97mgCH 3 NH 3 Br, 247.07 mg PbI 2 and 32.68 mg PbBr 2 Mix in a small reagent bottle, add 400 μL of dimethylformamide and 100 μL of dimethyl sulfoxide, stir the mixed solution at 50 °C for 3 h, and filter with an organic filter head to obtain 0.5 mL of 1.25 M perovskite precursor solution for the experiment;

[0043] Step 4: Take 50 μL of the perovskite precursor solution in step 3 and spin-coat it on the FTO transparent conductive substrate covered with the titanium dioxide electron transport layer, spin-coat it at high speed (4000 rpm) for 30 seconds, and immediately add 200 μL of chlorobenzene solution when there are 10 seconds left in the high-speed spin coating. After the addition is completed, heat treat it at 100°C for 20 minutes to prepare a perovskite film with a uniform and flat surface and a thickness of 600 nm;

[0044] Step 5: The perovskite film obtained in step 4 is placed in a constant temperature and humidity atmosphere (water vapor) with a humidity of 85% and a temperature of 85°C for recrystallization while still hot. After keeping warm and moist for 10 seconds, it is taken out and immediately placed in a dry environment to cool for 10 minutes to obtain a perovskite layer. The morphology of the perovskite layer is as follows: Figure 2 As shown, from Figure 2 It can be seen that the above atmosphere post-treatment can effectively reduce the grain boundaries in the perovskite layer;

[0045] Step 6: Spin-coat a layer of Spiro-OMeTAD with a thickness of 200 nm on the perovskite layer obtained in step 5, and then oxidize it in dry oxygen for 24 hours to obtain a hole transport layer;

[0046] Step 7: Evaporate a layer with an area of ​​0.1 cm on the hole transport layer of step 6 2 , an Au electrode with a thickness of 100nm, and a perovskite solar cell is obtained.

[0047] Example 2

[0048] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), an electron transport layer (tin oxide layer), a perovskite layer, a hole transport layer (Spiro-OMeTAD) and a metal electrode (Au) stacked in sequence from bottom to top, wherein the perovskite layer is prepared by recrystallizing a perovskite film for 60 seconds under a constant temperature and humidity atmosphere (water vapor) with a humidity of 60% and a temperature of 60°C. The preparation method specifically comprises the following steps:

[0049] Step 1: The same as the step in Example 1, to obtain clean FTO conductive glass as a transparent conductive substrate;

[0050] Step 2: Spin-coat 0.1 mL of tin dioxide colloidal solution on the FTO conductive glass and anneal at 150° C. for 30 min to obtain an electron transport layer;

[0051] Step 3: Prepare 1.55 mol / L perovskite precursor solution Cs in an argon glove box. 0.05 FA 0.85 MA 0.10 PbI 2.91 Br 0.09 : 20.2 mg CH 3 NH 3 Cl, 226.7 mg HC(=NH)NH 3 I. 17.5 mg CH 3 NH 3 Br, 750.4 mg PbI 2 and 20.3 mg CsI were mixed in a small reagent bottle, and 800 μL dimethylformamide and 200 μL dimethyl sulfoxide were added. The mixed solution was stirred at 60 °C for 2 h, and filtered through an organic filter head to obtain 1 mL of perovskite precursor solution for the experiment.

[0052] Step 4: Take 50 μL of the perovskite precursor solution in step 3 and spin-coat it on the FTO transparent conductive substrate covered with the tin dioxide electron transport layer, spin-coat it at high speed (4000 rpm) for 30 seconds, and immediately add 200 μL of anisole solution when there are 10 seconds left in the high-speed spin coating. After the addition is completed, heat treat it at 120° C. for 30 minutes to prepare a perovskite film with a uniform and flat surface and a thickness of 600 nm;

[0053] Step 5: The perovskite film obtained in step 4 is placed in a constant temperature and humidity atmosphere (water vapor) with a humidity of 60% and a temperature of 60°C for recrystallization while still hot. After keeping warm and moist for 60 seconds, it is taken out and immediately placed in a pure nitrogen protection environment for cooling for 10 minutes to obtain a perovskite layer. The morphology of the perovskite layer is as follows: Figure 2 shown.

[0054] Step 6: Prepare a hole transport layer in the same manner as in Example 1;

[0055] Step 7: Evaporate a layer with an area of ​​0.1 cm on the hole transport layer of step 6 2 , an Au electrode with a thickness of 100nm, and a perovskite solar cell is obtained.

[0056] Example 3

[0057] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), a hole transport layer (nickel oxide layer), a perovskite layer, an electron transport layer (C 60 The perovskite layer is prepared by recrystallizing the perovskite film for 30 seconds under a constant temperature and humidity atmosphere (water vapor) with a humidity of 80% and a temperature of 80°C. The specific preparation method comprises the following steps:

[0058] Step 1: The same as the step in Example 1, to obtain clean FTO conductive glass as the transparent conductive substrate 1;

[0059] Step 2: Spin-coat 0.1 mL of nickel oxide colloidal solution on FTO conductive glass and anneal at 150 degrees Celsius for 30 minutes to obtain a hole transport layer;

[0060] Step 3: Prepare 1.6 mol / L FAPbI in a nitrogen glove box 3 Perovskite precursor solution: 24.3 mg CH 3 NH 3 I. 154 mg HC(=NH)NH 3 I. 414 mg PbI 2 Mix in a small reagent bottle, add 400 μL of dimethylformamide and 100 μL of dimethyl sulfoxide, stir the mixed solution at 60 °C for 2 h, and filter with an organic filter head to obtain 0.5 mL of 1.6 M perovskite precursor solution for the experiment;

[0061] Step 4: Take 50 μL of the perovskite precursor solution in step 3 and spin-coat it on the FTO transparent conductive substrate covered with the nickel oxide hole transport layer, spin-coat it at high speed (6000 rpm) for 50 seconds, and immediately add 200 μL of anisole as an anti-solvent at the 10th second of high-speed spin-coating. After the addition is completed, heat treat it at 150° C. for 10 minutes in a 30% humidity environment to prepare a perovskite film with a uniform and flat surface and a thickness of 600 nm;

[0062] Step 5: Put the perovskite film obtained in step 4 into a constant temperature and humidity chamber with a humidity of 80% and a temperature of 80°C while it is still hot, take it out after keeping it warm and moist for 30 seconds, and immediately put it into a dry protective environment to cool for 10 minutes, so as to obtain a perovskite layer after atmosphere treatment;

[0063] Step 6: Deposit 1nm of LiF and 20nm of C on the perovskite layer using an evaporation process 60 As an electron transport layer;

[0064] Step 7: Evaporate a layer with an area of ​​0.1 cm on the electron transport layer of step 6 2, an Ag electrode with a thickness of 100 nm, and an atmosphere-post-treated perovskite solar cell is obtained.

[0065] Comparative Example 1

[0066] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), an electron transport layer (TiO 2 The only difference from Example 1 is that the perovskite layer of this comparative example was not subjected to atmosphere post-treatment during the preparation process, that is, the perovskite film was not placed in a constant temperature and humidity atmosphere to undergo a perovskite film recrystallization process. The morphology of the perovskite layer obtained in this comparative example is as follows: Figure 2 As shown, it can be seen from the figure that compared with Example 1, the crystal size of the perovskite layer in this comparative example is smaller, the gap between the crystals is larger, and the surface defect density is higher.

[0067] Comparative Example 2

[0068] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), an electron transport layer (tin oxide layer), a perovskite layer, a hole transport layer (Spiro-OMeTAD) and a metal electrode (Au) stacked in sequence from bottom to top. The only difference from Example 2 is that the perovskite layer of this comparative example is not subjected to atmosphere post-treatment during the preparation process, that is, the perovskite film is not placed in a constant temperature and humidity atmosphere to undergo a perovskite film recrystallization process. The morphology of the perovskite layer obtained in this comparative example is as follows: Figure 2 As shown, it can be seen from the figure that compared with Example 2, the crystal size of the perovskite layer in this comparative example is smaller, the gaps between the crystals are larger, and the surface defect density is higher.

[0069] Comparative Example 3

[0070] A perovskite solar cell comprises a transparent conductive substrate (FTO conductive glass), a hole transport layer (nickel oxide layer), a perovskite layer, an electron transport layer (C 60 layer) and a metal electrode (Ag), the only difference from Example 3 is that no atmosphere post-treatment is performed during the preparation of the perovskite layer in this comparative example, that is, the perovskite film is not placed in a constant temperature and humidity atmosphere to perform the perovskite film recrystallization process.

[0071] Performance test method: Under irradiation with 1 standard sun, the JV curve of the perovskite solar cell of each embodiment and comparative example is measured by a source meter or an electrochemical workstation. The data of the open circuit voltage, short circuit current, fill factor, and photoelectric conversion efficiency of the perovskite solar cell tested in each embodiment and comparative example are shown in Table 1.

[0072] Table 1

[0073]

[0074] The above-described embodiments only represent the embodiments of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. The present invention can also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be regarded as illustrative rather than restrictive in any respect. The scope of the present invention should be described by the attached claims, and any changes equivalent to the intention and scope of the claims should also be included in the scope of the present invention.

Claims

1. A method for post-treatment of a perovskite film by atmosphere, characterized in that: The following steps are involved: Step S1, first preparing a perovskite precursor solution into a perovskite precursor film, and then subjecting the perovskite precursor film to heat treatment to form a perovskite film; Step S2, placing the perovskite film in a constant temperature and humidity atmosphere to recrystallize the perovskite film; Step S3, cooling the recrystallized perovskite film to room temperature in a dry environment to obtain a perovskite layer.

2. The atmosphere post-treatment method of the perovskite film according to claim 1, characterized in that: The constant temperature and humidity conditions are: humidity is 70% to 90%, temperature is 40 to 90° C.; the atmosphere is water vapor or gas containing water vapor.

3. The atmosphere post-treatment method of perovskite film according to claim 2, characterized in that: The recrystallization time of the perovskite film is 10 to 120 seconds.

4. The atmosphere post-treatment method of the perovskite film according to claim 1, characterized in that: The perovskite precursor in the perovskite precursor solution is a compound of type AX and BX2, wherein A is CH3NH3 + 、HC(=NH)NH3 + , Cs + , Rb + or K + One or more of, B is Pb2 + and / or Sn2 + , X is one or more halogen ions.

5. The atmosphere post-treatment method of the perovskite film according to claim 4, characterized in that: The molar concentration of the perovskite precursor solution is 1.0-1.8 mol / L.

6. The atmosphere post-treatment method of the perovskite film according to claim 1, characterized in that: The heat treatment is carried out at a temperature of 100 to 150° C. and for a time of 10 to 60 minutes.

7. The atmosphere post-treatment method of a perovskite film according to any one of claims 1 to 6, characterized in that: The thickness of the perovskite film is 400-1000nm.

8. A perovskite solar cell, characterized in that: It comprises a transparent conductive substrate, an electron transport layer / hole transport layer, a perovskite layer, a hole transport layer / electron transport layer and a metal electrode stacked in sequence from bottom to top, wherein the perovskite layer is prepared by the atmosphere post-treatment method of the perovskite film according to any one of claims 1 to 7.

9. The perovskite solar cell according to claim 8, characterized in that: The material of the electron transport layer is tin oxide, zinc oxide, titanium oxide, PCBM or C 60 One or more of the above, wherein the thickness of the electron transport layer is 10 to 50 nm.

10. The perovskite solar cell according to claim 8, characterized in that: The material of the hole transport layer is one or more of Spiro-OMeTAD, PTAA, NiO, Me-4PACZ or MeO-2PACZ, and the thickness of the hole transport layer is 1 to 200 nm.

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