Method for producing perovskite films, related perovskite films and solar cells

Abstract

The present application provides a method for producing a perovskite film, a perovskite film, a solar cell, and a solar cell device. The method includes the steps of: (1) providing a target material containing lead, a halogen, and one or more alkali metals; (2) sputtering the target material to obtain a film, the process gas being a rare gas, optionally argon gas; (3) subjecting the obtained film to a chemical bath treatment, the chemical bath being a solution of AX, where A is selected from one or more of formamidine and methylamine, and X is a halogen; and (4) sputtering the obtained film using metal tin to obtain a perovskite film, the process gas being a rare gas, optionally a mixture of argon gas and a halogen gas. The method has excellent film formation quality and high process controllability.

Description

[Technical field]

[0001] The present application relates to the technical field of solar cells, and in particular to a method for producing a perovskite film and its associated perovskite films, solar cells and solar cell devices. [Background technology]

[0002] Perovskite film solar cells have the advantages of low recombination rate of electron-hole pairs, wide range of strong light absorption, etc., and therefore have become a hotspot in the research of next-generation solar cells. At present, the manufacturing methods of perovskite films mainly include solution chemical method, spin-coating method and vapor phase deposition method. Among them, the solution chemical method has low manufacturing cost and relatively simple process, and is the mainstream method for manufacturing high-quality film layers in laboratories, but such a method has low process stability and low reproducibility, which is disadvantageous for large-scale production. The coating method is the mainstream method for manufacturing large-area perovskite films, but its film formation is single, the influence of solution materials is large, and it cannot be flexibly controlled, and it is difficult to ensure the uniformity of the coating. The vapor phase deposition method in the prior art has high requirements for equipment and is difficult to control the relative ratio of precursors, which increases the difficulty of manufacturing high-quality film layers and serious waste of raw materials. Therefore, it is very meaningful to provide a new manufacturing method of perovskite films with excellent film formation quality and high process controllability. Summary of the Invention [Problem to be solved by the invention]

[0003] The present application has been made in view of the above problems, and an object of the present application is to provide a method for producing a perovskite film, which results in a uniform deposition of the perovskite film obtained by the method, and in which each process parameter of the method can be flexibly controlled, and the perovskite film can be adapted to various solar cell systems by adjusting the production parameters. [Means for solving the problem]

[0004] To achieve the above objectives, the present application provides a method for producing a perovskite film, the related perovskite film, a solar cell and a solar cell device.

[0005] A first aspect of the present application provides a method for producing a perovskite film, the method comprising: (1) providing a target material comprising the elements lead, a halogen, and one or more alkali metals; (2) sputtering the target material in step (1) to obtain a film, the process gas being a noble gas, optionally argon gas; (3) treating the film obtained in step (2) with a chemical bath, said chemical bath being a solution of AX, where A is selected from one or more of formamidine and methylamine, and X is a halogen; (4) sputtering the film obtained in step (3) using metallic tin to obtain a perovskite film, the process gas being a mixture of a rare gas, optionally argon gas, and a halogen gas; and Includes.

[0006] The method of the present application allows each parameter to be adjusted within a wide range, and the process stability and controllability are significantly improved compared to the prior art.

[0007] In any embodiment, optionally, based on the total mole number of each element in the target material, the target material in step (1) contains 10-40% alkali metal, 10-40% lead, and 50-90% halogen, the sum of which is 100%. When the molar content of each element is within the above range, the conversion efficiency of the corresponding solar cell is high.

[0008] In any embodiment, optionally, the halogen in step (1) is one or more of chlorine, bromine, or iodine, and the alkali metal is one or more of potassium, rubidium, or cesium.

[0009] In any embodiment, optionally, the concentration of the solution of AX in step (3) is 10-100 mg / ml, optionally 20-70 mg / ml, which can further improve the deposition uniformity of the perovskite film, thereby improving the conversion efficiency of the corresponding battery.

[0010] In any embodiment, optionally, the temperature of the chemical bath treatment in step (3) is 40-120° C., optionally 50-80° C., which can further improve the properties of the resulting perovskite film, thereby improving the conversion efficiency of the corresponding battery.

[0011] In any embodiment, optionally, the volume ratio of the rare gas, optionally argon gas, to the halogen gas in step (4) is 10:1 to 5:1. Using a mixture of rare gas and halogen gas as the process gas can further improve the properties of the resulting perovskite film, thereby improving the conversion efficiency of the corresponding cell.

[0012] In any embodiment, optionally, the halogen gas in step (4) comprises one or more of iodine vapor, bromine vapor, and chlorine vapor.

[0013] In any embodiment, step (4) is optionally carried out at a temperature between 50 and 250°C, optionally between 100 and 200°C.

[0014] A second aspect of the present application provides a perovskite film, the perovskite film being capable of being produced by a method according to the first aspect of the present application.

[0015] In any embodiment, optionally the thickness of the perovskite film is between 200 and 500 nm, optionally between 400 and 500 nm, and further optionally between 450 and 470 nm.

[0016] In any embodiment, optionally the band gap of the perovskite layer of the perovskite film is between 1.2 and 1.6 eV, optionally between 1.4 and 1.5 eV.

[0017] A third aspect of the present application provides a solar cell, the solar cell comprising: A transparent conductive electrode; A hole transport layer; A perovskite layer; an electron transport layer; a back electrode; and a back electrode, these components being disposed in this order from bottom to top; The positions of the hole transport layer and the electron transport layer are interchangeable, and the perovskite layer is a perovskite film produced by the method according to the first aspect of the present application or is a perovskite film according to the second aspect of the present application.

[0018] In any embodiment, optionally, the transparent conductive electrode is selected from one or more of indium tin oxide, fluorine doped tin dioxide.

[0019] In any embodiment, optionally, the hole transport layer is selected from the group consisting of poly(3,4-ethylenedioxythiophene), poly(styrenesulfonate) (PEDOT:PSS), poly(triarylamine) (PTAA), CuSCN, NiO x , CuI, MoO x The compound is selected from one or more of the following:

[0020] In any embodiment, optionally, the electron transport layer is selected from one or more of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), WO3, polyethyleneimine ethoxylate (PEIE), polyethyleneimine (PEI), ZnO, TiO2, [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM), SnO2, or fluorine-doped SnO2.

[0021] In any embodiment, optionally the back electrode is selected from one or more of indium tin oxide, tungsten doped indium oxide, aluminum doped zinc oxide (AZO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg.

[0022] A fourth aspect of the present application provides a solar cell device, the solar cell device comprising the solar cell according to the third aspect of the present application.

[0023] The solar cells and solar cell devices of the present application contain perovskite films obtained by the manufacturing method of the present application and therefore have the same advantages as the manufacturing method of the present application. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram of a solar cell according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the embodiments of the method for producing a perovskite film, the related perovskite film, the solar cell, and the solar cell device of the present application will be described in detail with appropriate reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters and duplicated description of structures that are actually the same may be omitted. This is to avoid the following description becoming unnecessarily long and to allow those skilled in the art to easily understand. Note that the drawings and the following description are provided to allow those skilled in the art to fully understand the present application, and are not intended to limit the subject matter described in the claims.

[0026] The "ranges" disclosed in this application are defined in the form of lower and upper limits, and a given range is defined by selecting one lower limit and one upper limit, and the selected lower and upper limits define the boundaries of the particular range. Such defined ranges may be inclusive or exclusive of the end values, and may be arbitrarily combined, i.e., any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also envisaged. It is noted that if 1 and 2 are listed as minimum range values, and 3, 4, and 5 are listed as maximum range values, then the ranges 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5 are all envisaged. In this application, unless otherwise specified, a numerical range "a-b" represents a shorthand representation of any combination of real numbers a-b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are recited herein, and "0-5" is merely a shorthand for combinations of these numerical values. Also, expressing a parameter as an integer ≧2 is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0027] Unless otherwise stated, all the embodiments and optional embodiments in the present application can be combined with each other to form a new technical solution.

[0028] Unless otherwise stated, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0029] Unless otherwise stated, all steps in this application may be performed in sequence or randomly, and preferably in sequence. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, the method mentioned above may further include step (c), which means that step (c) may be added to the method in any order, such as the method may include steps (a), (b) and (c), may include steps (a), (c) and (b), may include steps (c), (a) and (b), etc.

[0030] Unless otherwise specified, the terms "comprise" and "include" referred to in this application may be open ended or closed ended. For example, the terms "comprise" and "include" may further include or include other components not listed, or may include or include only the listed components.

[0031] As used in this application, the terms "more than" and "less than" are inclusive, for example, "one or more" means one or more, and "one or more of A and B" means "A," "B," or "A and B."

[0032] Unless otherwise stated, in this application, the term "or" is inclusive. For example, the term "A or B" means "A, B, or both A and B." More specifically, "A or B" is satisfied in the following cases: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) but B is true (or exists); and A and B are both true (or exist).

[0033] The inventors of the present application have found the following from practical work. In solar cells using perovskite films, in order to improve the conversion efficiency of the solar cells, the parameters required for different solar cells, such as the width of the band gap of the perovskite film, are not the same. However, the manufacturing method of the perovskite film in the prior art has low controllability of the process conditions and is difficult to adapt to the demands under different working conditions. In practical production, such shortcomings lead to an increase in the manufacturing cost of the perovskite film, while the quality of the obtained product may be low, and further cause a decrease in the conversion efficiency of the solar cell. For example, the manufacturing of perovskite films by solution chemical methods not only uses toxic solvents, but also has difficulties in controlling the uniformity of large-area film formation, greatly limiting the practical application of perovskite solar cells in the industry.

[0034] Through intensive research, the inventors have discovered a new method for producing perovskite films, which has significantly improved process stability and controllability compared to the prior art. Moreover, by further optimizing the processing steps and corresponding process parameters, the inventors have significantly improved the uniformity of the resulting film layer, improved the properties of the film layer, and made the solar cell including the resulting film layer have higher conversion efficiency.

[0035] [How perovskite films are manufactured] A first aspect of the present application provides a method for producing a perovskite film, the method comprising: (1) providing a target material comprising the elements lead, a halogen, and one or more alkali metals; (2) sputtering the target material in step (1) to obtain a film, the process gas being a noble gas, optionally argon gas; and (3) subjecting the film obtained in step (2) to a chemical bath treatment, the chemical bath being a solution of AX, where A is selected from one or more of formamidine and methylamine, and X is a halogen; (4) sputtering the film obtained in step (3) using metallic tin to obtain a perovskite film, wherein the process gas is a mixture of a noble gas, optionally argon gas, and a halogen gas.

[0036] The above-mentioned method for producing perovskite films allows the adjustment of each process parameter within a wide range by organically coupling various processing steps, and the process stability and controllability are significantly improved compared to conventional techniques.

[0037] Furthermore, the inventors have found through further research that by adjusting each process parameter of the manufacturing method, the uniformity of the obtained film can be further improved and the film formation quality can be improved, so that the solar cell including the obtained film layer has a higher conversion efficiency.

[0038] In some embodiments, optionally, the target material in step (1) contains 10-40% alkali metal, 10-40% lead, and 50-90% halogen, based on the total moles of each element in the target material, the sum of which is 100%.

[0039] Although the mechanism has not yet been elucidated, the inventors have found in their research that when the contents of the elements, especially the alkali metals and lead, are within the above ranges, the deposition of the perovskite film produced by the method described in the present application using the target material is more uniform, and the conversion efficiency of the finally produced solar cell is also higher.

[0040] In some embodiments, optionally, the halogen in step (1) is one or more of chlorine, bromine, or iodine, and the alkali metal is one or more of potassium, rubidium, or cesium.

[0041] In the present application, initial sputtering is performed in step (2) to obtain a film layer. It should be noted that the present application does not have any special requirements for the equipment for performing the sputtering step, and the equipment may be any equipment commonly used in the art. For example, step (2) may be performed in a magnetron sputtering equipment. It should be noted that when sputtering a target material, a substrate may be generally used, and the film formed on the substrate surface is the film described in step (2) of the present application. In the present specification, there is no particular restriction on the selection of the substrate. For example, the substrate may be any substrate commonly used in the art, such as ceramics, glass, tin dioxide, doped tin dioxide, etc.

[0042] The method described in the present application has no particular requirement for the temperature at which step (2) is carried out, and may be carried out at room temperature, for example. However, those skilled in the art will understand that the temperature should not be too low so that the sputtering rate is not too low.

[0043] In some embodiments, optionally, a noble gas, optionally argon gas, is used as a process gas in step (2), the presence of which is advantageous in improving the uniformity of the resulting perovskite film.

[0044] In some embodiments, optionally, the flow rate of the process gas in step (2) is between 100 and 500 sccm, optionally between 150 and 300 sccm.

[0045] In some embodiments, optionally, when step (2) is performed in a magnetron sputtering apparatus, the corresponding power of the magnetron sputtering apparatus is between 100W and 20kW, optionally between 500w and 5kw.

[0046] In some embodiments, optionally, the pressure of the chamber in the device when performing step (2) is 0 to 200 Pa, not including 0 Pa.

[0047] In some embodiments, optionally, the sputtering thickness in step (2) is between 10 and 300 nm.

[0048] In the method according to the present application, the membrane layer obtained in step (2) is subjected to a chemical bath treatment to introduce organic ions, such as methylamine ions (CH3NH3 + , M.A. + ) or formamidine ion (FA + ) can be introduced, thereby improving the film layer quality and further increasing the conversion efficiency of the corresponding solar cells.

[0049] In some embodiments, optionally, the concentration of the solution of AX in step (3) is 10-100 mg / ml, optionally 20-70 mg / ml.

[0050] If the concentration of the AX solution is lower than the above range, the improvement of the membrane layer performance by chemical bath treatment is not significant, and the conversion efficiency of the corresponding solar cell is low. If the concentration of the AX solution is too high, the introduction of methylamine ions or formamidine ions may be too large, which will rather impair the membrane layer quality. Optionally, if the concentration of the AX solution is 10-100mg / ml, optionally 20-70mg / ml, a more favorable effect of improving the membrane layer quality can be obtained.

[0051] In some embodiments, optionally, the solvent in the solution of AX is a solvent commonly used in the art, such as one or more of aromatic compounds, such as xylene, toluene, or alkylnaphthalene, chlorinated aromatic or aliphatic hydrocarbons, such as chlorobenzene, vinyl chloride, or methylene dichloride, alcohols and their ethers and esters, such as butanol, isopropanol, or ethylene glycol, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone, strongly polar solvents, such as dimethylformamide, dimethylsulfoxide, and water. Optionally, the solvent is one or more of isopropanol or chlorobenzene.

[0052] In some embodiments, optionally, the temperature of the chemical bath treatment in step (3) is from 40 to 120°C, optionally from 50 to 80°C.

[0053] A suitable chemical bath treatment temperature is favorable for promoting the penetration and migration of dopant ions into the membrane layer and improving the quality of the membrane layer. If the temperature of the chemical bath treatment is too low, for example, lower than room temperature, the progress of the chemical bath treatment will be very slow. If the temperature of the chemical bath treatment is higher than 150°C, it may cause the alteration of the membrane layer, degrade the properties of the membrane layer, and further reduce the conversion efficiency of the solar cell significantly.

[0054] The method according to the present application further includes step (4) of performing post-treatment on the chemically-bath-treated film. Different from step (2), the sputtering treatment in step (4) can improve the defects of the film layer quality caused by improper operation in the above-mentioned treatment steps, while the introduction of metal tin and halogen can further improve the film layer quality, so that the perovskite film produced has a uniform film thickness and excellent film quality, and further improves the conversion efficiency of the corresponding solar cell.

[0055] In some embodiments, optionally, the volume ratio of the noble gas, optionally argon gas, to the halogen gas in step (4) is from 10:1 to 5:1.

[0056] In the present application, the rare gas, optionally argon gas, plays a protective role to avoid damage to equipment or safety accidents caused by high temperature, while it can be used for bombardment to generate ions, such as bombardment of target material or halogen gas, thereby doping the obtained film layer to improve the film layer quality. Optionally, in the present application, under the condition that the total amount of the mixed gas of the rare gas, optionally argon gas and halogen gas is constant, adjusting the volume ratio of the two is advantageous to improve the film layer quality. In particular, when the volume ratio of the rare gas, optionally argon gas and halogen gas is 10:1 to 5:1, the improvement effect on the film layer quality is more significant.

[0057] In some embodiments, optionally, the halogen gas in step (4) comprises one or more of iodine vapor, bromine vapor, and chlorine vapor.

[0058] In some embodiments, optionally, the halogen gas in step (4) is a mixture of bromine vapor and iodine vapor, and the volume ratio of bromine vapor to iodine vapor is 1:3 to 3:1.

[0059] In some embodiments, optionally, the flow rate of the process gas in step (4) is between 100 and 500 sccm, optionally between 150 and 300 sccm.

[0060] In some embodiments, step (4) is optionally carried out at a temperature between 50 and 250°C, optionally between 100 and 200°C.

[0061] When step (4) is performed within the above temperature range, the corresponding sputtering reaction rate is fast, which is favorable for improving the device efficiency, while the high temperature helps to accelerate the annealing process for the entire film layer by accelerating the ion migration. In addition, the appropriate operating temperature also helps to avoid the occurrence of condensation and the deterioration of the film layer performance, thereby avoiding the deterioration of the conversion efficiency of the solar cell.

[0062] In some embodiments, optionally, when step (4) is performed in a magnetron sputtering apparatus, the corresponding power of the magnetron sputtering apparatus is 600 W to 5 kW.

[0063] In some embodiments, optionally, the pressure of the chamber in the device when performing step (4) is 0 to 200 Pa, not including 0 Pa.

[0064] In some embodiments, optionally, the sputtering thickness in step (4) is between 120 and 200 nm, optionally between 150 and 170 nm.

[0065] [Perovskite film] A second aspect of the present application provides a perovskite film, the perovskite film being capable of being produced by a method according to the first aspect of the present application.

[0066] In some embodiments, optionally the thickness of the perovskite film is between 200 and 500 nm, optionally between 400 and 500 nm, and further optionally between 450 and 470 nm.

[0067] It should be clarified that in this application, the "thickness of the perovskite film" refers to the thickness corresponding to the film obtained by carrying out all steps (1) to (4).

[0068] In some embodiments, optionally the band gap of the perovskite layer of the perovskite film is between 1.2 and 1.6 eV, optionally between 1.4 and 1.5 eV.

[0069] [Solar cell] A third aspect of the present application provides a solar cell, the solar cell comprising: A transparent conductive electrode; A hole transport layer; A perovskite layer; an electron transport layer; A back electrode; These components are installed in this order from bottom to top. The positions of the hole transport layer and the electron transport layer are interchangeable, and the perovskite layer is a perovskite film produced by the method according to the first aspect of the present application or is a perovskite film according to the second aspect of the present application.

[0070] In some embodiments, optionally, the transparent conductive electrode is selected from one or more of indium tin oxide, fluorine doped tin dioxide.

[0071] In some embodiments, the hole transport layer is optionally made of poly(3,4-ethylenedioxythiophene), polystyrene sulfonate (PEDOT:PSS), polytriarylamine (PTAA), CuSCN, NiO x , CuI, MoO x The compound is selected from one or more of the following:

[0072] In some embodiments, optionally, the electron transport layer is selected from one or more of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), WO3, polyethyleneimine ethoxylate (PEIE), polyethyleneimine (PEI), ZnO, TiO2, [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM), SnO2, or fluorine-doped SnO2.

[0073] In some embodiments, optionally, the back electrode is selected from one or more of indium tin oxide, tungsten doped indium oxide, aluminum doped zinc oxide (AZO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg.

[0074] In some embodiments, optionally, the solar cell described in the present application may be manufactured by a method commonly used in the art, for example, a transparent conductive electrode, a hole transport layer, a perovskite layer, an electron transport layer and a back electrode layer may be sequentially stacked, and then rolled and pressed, and the positions of the hole transport layer and the electron transport layer may be interchanged.

[0075] [Solar cell devices] Perovskite films have a very wide range of applications in functional materials, especially in the photoelectric field. For example, the present application studies the application of the perovskite film produced by the method described in the present application in the solar cell field. It should be understood that the examples provided by the present application are only intended to illustrate the applications of the perovskite film obtained by the production method of the present application, and as will be understood by those skilled in the art, the applications of the perovskite film are not limited to the exemplified applications.

[0076] A fourth aspect of the present application provides a solar cell device comprising one or more of a perovskite film produced by the method of the first aspect of the present application, a perovskite film of the second aspect of the present application, or a solar cell according to the third aspect of the present application.

[0077] Working Example The following describes the examples of the present application. The examples described below are illustrative and are only for interpreting the present application, and should not be understood as limitations on the present application. If no specific techniques or conditions are specified in the examples, they will be performed according to the techniques or conditions described in the technical literature or the product instructions. For reagents or instruments used, those without the manufacturer's name are all common products that can be purchased commercially.

[0078] The origins of the raw materials used in the examples are as shown in the table below.

[0079] [Table 1]

[0080] Example 1-1 Fabrication of perovskite films (1) Take a set of fluorine-doped tin dioxide (FTO, 10% fluorine doping based on the weight of tin dioxide) conductive glass with a specification of 1.5 cm x 1.5 cm x 2.2 mm, and use a laser marking machine to etch and remove part of the FTO (the unetched area is a square area extending 0.5 cm from the center of the 1.5 cm x 1.5 cm surface of the FTO to each of the four sides). Wash the etched FTO conductive glass sheet several times using acetone and isopropanol in sequence, and finally immerse it in deionized water and ultrasonicate for 10 minutes. After the foreign matter and dirt on the glass surface are removed, the obtained material is dried to be used as the substrate.

[0081] (2) In a magnetron sputtering machine, the substrate obtained in step (1) was sputtered using the target material 1. A high-frequency power source was used, the power was 3 kW, the pressure in the magnetron sputtering machine chamber was 0.3 Pa, the process gas was argon gas, the argon gas flow rate was 500 sccm, the coating time (i.e., sputtering processing time) was 10 minutes, and the thickness of the obtained film layer was 200 nm.

[0082] (3) The membrane layer obtained in step (2) was transferred into 100 ml of an isopropanol solution of formamidine iodide for chemical bath treatment, the concentration of the solution was 60 mg / ml, the bath treatment temperature was 50° C., and the treatment time was 20 minutes, and then it was dried to remove the solvent.

[0083] (4) The film layer obtained in step (3) was sputtered in a magnetron sputtering machine. A metal tin target material was used, and the process gas was a mixed gas of argon gas, iodine vapor, and bromine vapor with a volume ratio of 20:1:1, with the flow rate of argon gas in the process gas being 200sccm, and the flow rates of iodine vapor and bromine vapor both being 10sccm. A high-frequency power source was used, with a power of 2kW, the temperature in the magnetron sputtering machine chamber being 100°C, the chamber pressure being 0.3Pa, and the coating time (i.e., sputtering processing time) being 40 minutes. The film thickness increased after the sputtering processing in this step was 150nm.

[0084] Through the above steps, the perovskite film of the present application was obtained.

[0085] Perovskite solar cell manufacturing (1) Take a set of fluorine-doped tin dioxide (FTO, fluorine doping amount 10% based on the weight of tin dioxide) conductive glass with a specification of 1.5 cm × 1.5 cm × 2.2 mm, and use a laser marking machine to etch and remove part of the FTO (the unetched area is a square area extending 0.5 cm from the center of the FTO to each of the four sides), wash the etched FTO conductive glass sheet several times using acetone and isopropanol in sequence, and finally immerse it in deionized water and ultrasonicate for 10 minutes, and after the foreign matter and dirt on the glass surface are removed, the obtained material is used as the substrate.

[0086] (2) The FTO conductive glass sheet obtained in step (1) is dried in a blower dryer to remove moisture, and then transferred to a magnetron sputtering machine for sputter coating with nickel oxide, using a high frequency power supply, the power is 1.5kW, the temperature in the magnetron sputtering machine chamber is 50°C, the chamber pressure is 0.2Pa, the argon gas flow rate is 300sccm, the oxygen gas flow rate is 50sccm, the coating time is 5 minutes, and the thickness of the obtained film layer is 30nm.

[0087] (3) Using the nickel oxide sputter-coated FTO conductive glass obtained in step (2) as a substrate, a perovskite film as described in the present application is fabricated on the substrate, and the fabrication process is the same as the fabrication process of the perovskite film described above.

[0088] (4) The sheet with sputtered perovskite film obtained in step (3) was placed in a vacuum coating machine, and 20 g of C60 (fullerene C60) and 20 g of BCP powder (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) were placed in a magnetron sputtering machine, respectively, and C60 was first evaporated at 0.05 Å / s to 5 nm, then evaporated at 0.1 Å / s to 30 nm, and BCP was evaporated at 0.05 Å / s to 2 nm, then evaporated at 0.1 Å / s to 8 nm.

[0089] (5) The sheet obtained in step (4) is placed into a deposition machine, and one layer of Ag electrode is deposited, and the thickness of the Ag electrode is 50 nm.

[0090] Through the above steps, the perovskite solar cell described in this application was obtained.

[0091] Test methods for relevant parameters Bandgap testing of perovskite films The light transmittance and absorption spectrum of the film were measured using a Shimadzu UV-3600 spectrophotometer. A 5cm x 5cm x 2.2mm white glass coated with a perovskite film layer was selected and placed on the test window, and the light transmittance and absorption formula of 300-1100nm was selected from the software to perform the test, and the light transmittance and absorption spectrum of the perovskite film layer were obtained. Furthermore, the band gap value of the perovskite film was obtained by converting the Tauc curve into the intersection point between the tangent and the energy axis.

[0092] Efficiency testing of perovskite solar cells Based on the efficiency test method of the standard IEC61215:2016, the IVS-KA6000 from Guangyan Technology Co., Ltd. was used to test the efficiency of the assembly.

[0093] Examples 1-2 to 1-5 In the process of producing the perovskite film, the concentrations of the isopropanol solutions of formamidine iodide were 10 mg / ml, 20 mg / ml, 70 mg / ml and 100 mg / ml, respectively, except that the other conditions of Examples 1-2 to 1-5 were the same as those of Example 1-1.

[0094] Examples 1-6 to 1-9 In the process of producing the perovskite film, the temperatures of the chemical bath treatments are 40° C., 80° C., 100° C. and 120° C., respectively, except that the other conditions of Examples 1-6 to 1-9 are the same as those of Example 1-1.

[0095] Comparative Example 1 In the process of preparing the perovskite film, the concentration of the isopropanol solution of formamidine iodide is 5 mg / ml, except that the other conditions of Comparative Example 1 are the same as those of Example 1-1.

[0096] Comparative Example 2-3 In the process of preparing the perovskite film, the temperatures of the chemical bath treatment are 150°C and 170°C, respectively, except that the other conditions of Comparative Example 2-3 are the same as those of Example 1-1.

[0097] Comparative Example 4 Except for the fact that no chemical bath treatment was performed in the process of producing the perovskite film, the other conditions of Comparative Example 4 were the same as those of Example 1-1.

[0098] [Table 2]

[0099] As can be seen from Table I, the conversion efficiency of the solar cell can be effectively improved by chemically treating the obtained perovskite film. However, if the concentration of AX is too low or the temperature of the chemical bath treatment is too high, the increase in the chemical bath treatment may actually deteriorate the performance of the perovskite film and cause a decrease in the conversion efficiency of the solar cell.

[0100] Examples 2-1 to 2-5 In the process of producing the perovskite film, the volume ratios of argon gas, iodine vapor, and bromine vapor in the post-treatment process of step (4) were 20:1:1, 10:1:1, 20:0.5:0.5, 20:1.5:0.5, and 10:0:1, respectively. The other conditions of Examples 2-1 to 2-5 were the same as those of Example 1-1.

[0101] Comparative Example 5-6 In the process of producing the perovskite film, the volume ratios of argon gas, iodine vapor, and bromine vapor in the post-treatment process of step (4) were 0:0:0 and 1:0:0, respectively, except that the other conditions of Comparative Example 5-6 were the same as those of Example 1-1.

[0102] [Table 3]

[0103] As can be seen from Table II, when argon gas and halogen gas are present simultaneously in the post-treatment process of step (4), the performance of the perovskite film can be effectively improved and the efficiency of the solar cell can be improved. In particular, when the volume ratio of argon gas to halogen gas is 10:1 to 5:1, the conversion efficiency of the solar cell can be further improved.

[0104] Examples 3-1 to 3-4 In the process of producing the perovskite film, the sputtering temperatures in the post-treatment process of step (4) were 50°C, 150°C, 200°C, and 250°C, respectively, except that the other conditions in Examples 3-1 to 3-4 were the same as those in Example 1-1.

[0105] Comparative Examples 7-8 In the process of preparing the perovskite film, the sputtering temperatures during the post-treatment process of step (4) are 30°C and 300°C, respectively, except that the other conditions of Comparative Examples 7-8 are the same as those of Example 1-1.

[0106] [Table 4]

[0107] As can be seen from Table III, when the sputtering temperature in the post-treatment process of step (4) is 50-250°C, it is favorable to improve the performance of the perovskite film, thereby improving the efficiency of the solar cell. In particular, when the sputtering temperature is 100-200°C, the improvement effect on the efficiency of the solar cell is more significant.

[0108] It should be noted that the present application is not limited to the above-mentioned embodiment. The above-mentioned embodiment is an example, and any embodiment having substantially the same configuration as the technical idea and the same effect within the scope of the technical proposal of the present application is included in the technical scope of the present application. In addition, various modifications that a person skilled in the art can make to the embodiment and other forms constructed by combining some of the components in the embodiment are also included in the scope of the present application, within the scope of the purpose of the present application. [Explanation of symbols]

[0109] 1. Rear electrode, 2. Hole transport layer, 3. Perovskite layer, 4. Electron transport layer, 5. Transparent conductive electrode, 6. Glass

Claims

1. A method for producing a perovskite film, comprising the steps of: (1) providing a target material including the elements lead, a halogen, and one or more alkali metals; (2) performing sputtering using the target material in step (1) to obtain a film, the process gas being a rare gas, optionally argon gas; and (3) treating the film obtained in step (2) with a chemical bath, the chemical bath being a solution of AX, where A is selected from one or more of formamidine and methylamine, and X is a halogen; (4) sputtering the film obtained in step (3) using metallic tin to obtain a perovskite film, the process gas being a mixture of a rare gas, optionally argon gas, and a halogen gas; and A method for producing a perovskite film comprising:

2. 2. The method according to claim 1, wherein the target material in step (1) contains 10 to 40% alkali metal, 10 to 40% lead, and 50 to 90% halogen, based on the total moles of each element in the target material, the sum of which is 100%.

3. 3. The method of claim 1, wherein the halogen in step (1) is one or more of chlorine, bromine, or iodine, and the alkali metal is one or more of potassium, rubidium, or cesium.

4. The method according to any one of claims 1 to 3, wherein the concentration of the solution of AX in step (3) is 10 to 100 mg / ml, optionally 20 to 70 mg / ml.

5. The method according to any one of claims 1 to 4, wherein the temperature of the chemical bath treatment in step (3) is between 40°C and 120°C, optionally between 50°C and 80°C.

6. The method according to any one of claims 1 to 5, wherein the volume ratio of the rare gas, optionally argon gas, to the halogen gas in step (4) is 10:1 to 5:

1.

7. The method according to any one of claims 1 to 6, wherein the halogen gas in step (4) comprises one or more of iodine vapor, bromine vapor, and chlorine vapor.

8. The method according to any one of claims 1 to 7, wherein step (4) is carried out at a temperature of from 50 to 250°C, optionally from 100 to 200°C.

9. 9. A perovskite film produced by the method of any one of claims 1 to 8.

10. 10. The perovskite film of claim 9, wherein the thickness of the perovskite film is from 200 to 500 nm, optionally from 400 to 500 nm, further optionally from 450 to 470 nm.

11. 11. The perovskite film according to claim 9 or 10, wherein the band gap of the perovskite layer of the perovskite film is from 1.2 to 1.6 eV, optionally from 1.4 to 1.5 eV.

12. A solar cell comprising: A transparent conductive electrode; A hole transport layer; A perovskite layer; an electron transport layer; A back electrode; Including, the transparent conductive electrode, the hole transport layer, the perovskite layer, the electron transport layer and the rear electrode are sequentially disposed in this order from bottom to top; the positions of the hole transport layer and the electron transport layer are interchangeable; A solar cell, wherein the perovskite layer is a perovskite film produced by the method according to any one of claims 1 to 8 or a perovskite film according to any one of claims 9 to 11.

13. 13. The solar cell of claim 12, wherein the transparent conductive electrode is selected from one or more of the following: indium tin oxide, fluorine doped tin dioxide.

14. The hole transport layer may be made of poly(3,4-ethylenedioxythiophene), polystyrene sulfonate (PEDOT:PSS), polytriarylamine (PTAA), CuSCN, NiO ｘ , CuI, MoO ｘ The solar cell according to claim 12 or 13, wherein the organic solvent is selected from one or more of the following:

15. The electron transport layer is made of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), WO ３ , polyethyleneimine ethoxylate (PEIE), polyethyleneimine (PEI), ZnO, TiO ２ , [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM), SnO ２ or fluorine-doped SnO ２ The solar cell according to any one of claims 12 to 14, wherein the solar cell is selected from one or more of the following:

16. The solar cell according to any one of claims 12 to 15, wherein the back electrode is selected from one or more of indium tin oxide, tungsten-doped indium oxide, aluminum-doped zinc oxide (AZO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, and Mg.

17. A solar cell device comprising the solar cell according to any one of claims 12 to 16.

Images