Perovskite precursor and preparation method thereof

Abstract

The invention belongs to the technical field of perovskite batteries, and particularly relates to a perovskite precursor and a preparation method thereof. According to the invention, the perovskite precursor is prepared into an emulsion form, Ge < 4 + > is adopted to prepare the perovskite precursor, and the silicon dioxide nano oxide, the additive and the stabilizer are introduced into the emulsion precursor, so that the moisture resistance and hydrophobicity of the perovskite thin film are improved, and tiny liquid drops in the emulsion are used as a template for perovskite crystal growth, so that the perovskite thin film is prepared. The size and form of perovskite crystals are controlled, the silicon dioxide nano oxide can passivate defect states on the surface of perovskite and reduce recombination of electron-hole pairs, and a precursor in the emulsion is also beneficial to passivating surface defects in the curing process, reducing defect state density and improving device performance. The device prepared by using the perovskite precursor prepared by the invention has good photoelectric property and stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite, and in particular relates to a perovskite precursor and a preparation method thereof. Background Art

[0002] Perovskite refers to a compound with the ABX3 configuration of the perovskite structure. It is an ideal photovoltaic material with bipolar carrier transport capability, high carrier mobility, high visible light coefficient, and suitable bandgap width. Because perovskite nanocrystals have more significant quantum size confinement effect and crystal structure stability, they show unique research value and application prospects in many optoelectronic research fields.

[0003] Lead-based perovskite nanocrystals can be synthesized by ligand-assisted reprecipitation or hot injection. However, the ligand-assisted reprecipitation method causes the destruction of these nanoparticles due to the destructive polar solvents used in the synthesis of perovskite precursors, such as N, N-dimethylacetamide (DMF) and N-methylpyrrolidone (NMP), so the obtained fluorescence quantum yield and alternating stability are relatively low. From the perspective of perovskite precursor synthesis, the halide precursors available are limited, mainly concentrated in toxic organic halides such as trimethylchlorosilane and benzoyl bromide, and most of the perovskite nanocrystals prepared by these organic halides still have halogen vacancy defects, resulting in the fluorescence performance not being able to fully reach the ideal value. In some other alternatives of inorganic metal halides, these inorganic metal halides will introduce excess and additional metal ions into the perovskite lattice, thereby affecting the basic crystallographic properties of the target product. Therefore, we urgently need to develop a green synthesis method to synthesize stable and non-aging perovskite precursors, so as to prepare perovskite devices with good performance. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a perovskite precursor and a preparation method thereof. The present invention prepares the perovskite precursor in the form of an emulsion, using Ge 4+ The perovskite precursor was prepared, and silicon dioxide nano-oxide, additives and stabilizers were introduced into the emulsion precursor to improve the moisture resistance and hydrophobicity of the perovskite film. The tiny droplets in the emulsion were used as templates for the growth of perovskite crystals, which helped to control the size and morphology of the perovskite crystals, thereby optimizing their photoelectric properties. The silicon dioxide nano-oxide can passivate the defect states on the surface of the perovskite and reduce the recombination of electron-hole pairs. The precursor in the form of an emulsion also helps to passivate surface defects during the curing process, reduce the defect state density, and improve device performance. Ge 4+It is an inorganic halide, which significantly improves the photoelectric properties and structural stability of nanocrystals. After adding DHP, the activity of iodide ions and formamidine ions is effectively inhibited, the reaction path of deprotonation of methylammonium cations is cut off, and the reaction of HI, I2 and I in the precursor solution is effectively inhibited. 3- The production of by-products.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows: The present invention provides a perovskite precursor, which is prepared from the following raw materials in parts by weight: 50-80 parts of perovskite material, 10-30 parts of organic solvent, 0.1-5 parts of additive, 1-5 parts of surfactant, 0.1-5 parts of stabilizer, and 3-8 parts of nano oxide; Preferably, the perovskite material is an ABX3 type perovskite, wherein A is one or more of formamidine iodide (FAI), methylamine bromide (MABr), methylamine chloride (MACl), dimethylamine hydroiodide (DMAI) and phenylethylamine iodide (PEAI), B is one or more of GeCl4, GeBr4 and GeI4, and X is an iodide ion or a bromide ion.

[0006] Preferably, the organic solvent is one or more of oleic acid, octadecene and oleylamine.

[0007] Preferably, the stabilizer is acetylacetone.

[0008] Preferably, the surfactant is one or more of polyvinyl alcohol (PVA), sodium dodecyl sulfate (SDS) and sodium oleate.

[0009] Preferably, the additive is diethyl hydroxymethylphosphonate (DHP).

[0010] Preferably, the nano-oxide is silicon dioxide nano-oxide.

[0011] Furthermore, the raw materials for preparing the silicon dioxide nano-oxide are: silicon dioxide and methyl silicone oil. The preparation method of the silicon dioxide nano-oxide is: weigh silicon dioxide and add it to anhydrous ethanol, ultrasonically treat it for 15 minutes, add methyl silicone oil thereto, the amount ratio of silicon dioxide, methyl silicone oil and anhydrous ethanol is 1 g:5-10 mL:30 mL, react at 50°C for 16 hours, collect the precipitate by centrifugation at 10000 rpm for 10 minutes, wash the precipitate, dry it at a constant temperature of 60°C for 24 hours, and grind it to obtain silicon dioxide nano-oxide.

[0012] The present invention also provides a method for preparing a perovskite precursor, which specifically comprises the following steps: S1, weighing the perovskite material and the organic solvent according to weight, dissolving the perovskite material in the organic solvent, stirring with a constant temperature stirrer at 60 °C for 2 h to obtain a solution; S2, adding additives by weight to the solution obtained in step S1, stirring at a constant temperature for 1-2 h to obtain a mixed solution; S3, adding a surfactant by weight to the mixed solution obtained in step S2, dispersing the mixed solution using a high-speed shearing machine at a speed of 12000 rpm, and then using an ultrasonic cell disruptor to perform ultrasound for 10 minutes, with the ultrasound setting operating state being 5 s on and 5 s off, and the amplitude being set to 50%, to obtain a primary emulsion; S4, adding nano-oxide by weight and stabilizer by weight to the primary emulsion obtained in step S3, and stirring for 1-5 min at a speed of 12000-15000 rpm using a high-speed shearing machine to emulsify and form an emulsion; S5, sealing and storing the emulsion obtained in step S4 for 2-6 days to obtain a perovskite precursor.

[0013] In addition, the present invention also provides a perovskite film, which is prepared from the above-mentioned perovskite precursor. The preparation method of the perovskite film specifically includes the following steps: Y1, will cut into 1 cm 2 The ITO glass substrate was cleaned and dried, fixed on the suction cup of the coating machine, and a drop of the prepared perovskite precursor was dropped on the substrate with a dropper so that the perovskite precursor covered the entire substrate. The speed of the coating machine was set to a low speed of 500 rpm for 10 s and a high speed of 3000 rpm for 30 s. The coating machine was turned on and waited for all the spin coating to be completed to obtain a spin-coated film. Y2, transfer the film spin-coated in step Y1 to a platform furnace at 100°C for pyrolysis for 15 minutes to evaporate and decompose the residual solvent in the film, and allow the film to begin pre-crystallization. Raise the temperature to 150°C, and continue drying for 30 minutes to solidify the film and complete crystallization to obtain a perovskite film.

[0014] Furthermore, the high-speed shearing machine model is Ultra-TurraT18, the ultrasonic cell disruptor model is BILON-150Y, and the gelling machine model is IC5000-S.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention prepares the perovskite precursor in the form of an emulsion, using Ge 4+The perovskite precursor is prepared, and silicon dioxide nano-oxide is introduced into the emulsion precursor, which improves the moisture resistance and hydrophobicity of the perovskite film and the long-term stability of the device. The precursor in the form of an emulsion can be more evenly dispersed in the solution, so that a more uniform film is obtained during coating and film formation, and defects and pinholes are reduced. The use of tiny droplets in the emulsion as a template for crystal growth helps to control the size and morphology of the perovskite crystals, thereby optimizing its photoelectric properties. The emulsion helps to isolate moisture from the air, reduce the sensitivity of the perovskite precursor to humidity during the preparation process, and improve the stability of the material. The addition of hydrophobic silicon dioxide further enhances the resistance of the perovskite material to moisture. Improve long-term stability. The emulsion form can improve the interface compatibility between the perovskite precursor and the substrate material, reduce interface defects, and improve carrier transfer efficiency. The perovskite film prepared by the emulsion method has better thermal stability because the components in the emulsion can promote the formation of a more stable crystal structure. The addition of silicon dioxide nano-oxide improves the mechanical strength of the perovskite film, making it more durable during manufacturing and application. Silicon dioxide can passivate the defect states on the surface of the perovskite and reduce the recombination of electron-hole pairs, thereby improving the photoelectric properties of the perovskite material. The precursor in the emulsion also helps to passivate surface defects and reduce the defect state density during the curing process, thereby improving device performance. Ge 4+ It is a low-toxic halogen source. Compared with the traditionally used organic halides, Ge 4+ It is an inorganic halide that does not cause damage to the environment and organisms. It significantly improves the optoelectronic properties and structural stability of nanocrystals. GeX4 can produce nanocrystals with adjustable and controllable sizes, and the synthesized products have higher luminescence intensity, longer fluorescence lifetime, higher fluorescence yield and better air stability. The Ge element will not enter the final perovskite nanocrystal lattice and affect the basic crystallographic properties of the target product. Ge halides have a higher dechlorination barrier, making the halogen ion release process slower and easier to control, thereby improving the stoichiometric ratio and surface defect state of the perovskite final product, and ultimately improving the overall optical properties and crystal structure stability of the nanocrystals. The addition of the additive DHP effectively inhibits the activity of iodide ions and formamidinium ions, cuts off the reaction path of deprotonation of methylammonium cations, and effectively inhibits HI, I2 and I in the precursor solution. 3- The production of byproducts such as DHP and formamidine ions can be suppressed, and hydrogen bonds can be formed between DHP and formamidine ions to further inhibit the production of other byproducts. The perovskite precursor prepared by the present invention has good stability and is not easy to age. The preparation method of the present invention simplifies the manufacturing process, improves the processing efficiency, and can prepare high-quality, large-area perovskite films, so it has great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A cross-sectional SEM image of a perovskite film prepared from a perovskite precursor prepared in the present invention; Figure 2 A schematic diagram of the contact angle of a perovskite film prepared from a perovskite precursor prepared in the present invention; Figure 3 The stability of the device prepared by the perovskite precursor prepared by the present invention. DETAILED DESCRIPTION

[0017] In order to make the technical solution of the present invention better understood by the technical personnel in the field, and to make the above-mentioned features, purposes and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the embodiments. The embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0018] It should be noted that, unless otherwise specified, the chemical reagents involved in the present invention were purchased through commercial channels.

[0019] Example 1: This example provides a perovskite precursor, which is prepared from the following raw materials in parts by weight: 50 parts of perovskite material, 10 parts of organic solvent, 0.1 parts of diethyl hydroxymethylphosphonate, 1 part of polyvinyl alcohol, 0.1 parts of acetylacetone, and 3 parts of silicon dioxide nano-oxide; The perovskite material is an ABX3 type perovskite, wherein A is a mixture of formamidine iodide and methylammonium bromide, the mass ratio of the two is 1:1, B is GeCl4, and X is an iodide ion; The organic solvent is a mixed solvent of oleic acid, octadecene and oleylamine, and the volume ratio of the three is 1:1:0.5; The raw materials for preparing the silicon dioxide nano-oxide are silicon dioxide and methyl silicone oil. The preparation method of the silicon dioxide nano-oxide is as follows: weigh silicon dioxide and add it to anhydrous ethanol, perform ultrasonic treatment for 15 minutes, add methyl silicone oil thereto, the amount ratio of silicon dioxide, methyl silicone oil and anhydrous ethanol is 1 g:5 mL:30 mL, react at 50°C for 16 hours, collect the precipitate by centrifugation at 10000 rpm for 10 minutes, wash the precipitate, dry it at a constant temperature of 60°C for 24 hours, and grind it to obtain the silicon dioxide nano-oxide.

[0020] This embodiment also provides a method for preparing a perovskite precursor, which specifically includes the following steps: S1, weigh 50 parts of perovskite material, dissolve it in 10 parts of a mixed solvent of oleic acid, octadecene and oleylamine, stir it with a constant temperature stirrer at 500 rpm for 2 h at 60 °C to obtain a solution; S2, adding an additive diethyl hydroxymethylphosphonate to the solution obtained in step S1, stirring at a constant temperature for 1 h, stirring at a speed of 300 rpm at 60° C., to obtain a mixed solution; S3, adding 1 part of surfactant polyvinyl alcohol to the mixed solution obtained in step S2, shearing with a high-speed shearing machine at a speed of 12000 rpm, and then ultrasonicating with an ultrasonic cell disruptor for 10 min, with the ultrasonic setting operating state of 5 s on and 5 s off, and the amplitude set to 50%, to obtain a primary emulsion; S4, adding 3 parts of silicon dioxide nano-oxide and 0.1 parts of stabilizer to the primary emulsion obtained in step S3, and using a high-speed shearing machine at a speed of 12000 rpm for 1 min to emulsify and form an emulsion; S5, sealing and storing the emulsion obtained in step S4 for 2 days to obtain a perovskite precursor.

[0021] In addition, this embodiment further provides a perovskite film, which is prepared from the above-mentioned perovskite precursor. The preparation method of the perovskite film specifically includes the following steps: Y1, will cut into 1 cm 2 The ITO glass substrate was cleaned and dried, fixed on the suction cup of the coating machine, and a drop of the prepared perovskite precursor was dropped on the substrate with a dropper so that the perovskite precursor covered the entire substrate. The speed of the coating machine was set to a low speed of 500 rpm for 10 s and a high speed of 3000 rpm for 30 s. The coating machine was turned on and waited for all the spin coating to be completed to obtain a spin-coated film. Y2, transfer the film spin-coated in step Y1 to a platform furnace at 100°C for pyrolysis for 15 minutes to evaporate and decompose the residual solvent in the film, and allow the film to begin pre-crystallization. Raise the temperature to 150°C, and continue drying for 30 minutes to solidify the film and complete crystallization to obtain a perovskite film.

[0022] Example 2: This example provides a perovskite precursor, which is prepared from the following raw materials in parts by weight: 60 parts of perovskite material, 20 parts of oleic acid, 3 parts of diethyl hydroxymethylphosphonate, 2.5 parts of sodium dodecyl sulfonate, 3 parts of acetylacetone, and 5 parts of silicon dioxide nano-oxide; The perovskite material is an ABX3 type perovskite, wherein A is a mixture of methylammonium chloride and dimethylammonium iodide, the mass ratio of the two is 1:1, B is GeBr4, and X is a bromide ion; The raw materials for preparing the silicon dioxide nano-oxide are silicon dioxide and methyl silicone oil. The preparation method of the silicon dioxide nano-oxide is as follows: weigh silicon dioxide and add it to anhydrous ethanol, perform ultrasonic treatment for 15 minutes, add methyl silicone oil thereto, the amount ratio of silicon dioxide, methyl silicone oil and anhydrous ethanol is 1 g:6 mL:30 mL, react at 50°C for 16 hours, collect the precipitate by centrifugation at 10000 rpm for 10 minutes, wash the precipitate, dry it at a constant temperature of 60°C for 24 hours, and grind it to obtain the silicon dioxide nano-oxide.

[0023] This embodiment also provides a method for preparing a perovskite precursor, which specifically includes the following steps: S1, weigh 60 parts of perovskite material, dissolve it in 20 parts of oleic acid, stir it with a constant temperature stirrer at 500 rpm at 60 °C for 2 h to obtain a solution; S2, adding 3 parts of additive diethyl hydroxymethylphosphonate to the solution obtained in step S1, stirring at a constant temperature for 1.5 h to obtain a mixed solution; S3, adding 2.5 parts of a surfactant sodium dodecyl sulfate to the mixed solution obtained in step S2, shearing with a high-speed shearing machine at a speed of 14000 rpm, and then ultrasonicating with an ultrasonic cell disruptor for 10 min, with the ultrasonic setting operating state of 5 s on and 5 s off, and the amplitude set to 50%, to obtain a primary emulsion; S4, adding silicon dioxide nano-oxide by weight to the primary emulsion obtained in step S3, and adding 3 parts of stabilizer acetylacetone, and using a high-speed shearing machine at a speed of 12000 rpm for 3 minutes to emulsify and form an emulsion; S5, sealing and storing the emulsion obtained in step S4 for 4 days to obtain a perovskite precursor.

[0024] In addition, this embodiment further provides a perovskite film, which is prepared from the above-mentioned perovskite precursor. The preparation method of the perovskite film specifically includes the following steps: Y1, will cut into 1 cm 2 The ITO glass substrate was cleaned and dried, fixed on the suction cup of the coating machine, and a drop of the prepared perovskite precursor was dropped on the substrate with a dropper so that the perovskite precursor covered the entire substrate. The speed of the coating machine was set to a low speed of 500 rpm for 10 s and a high speed of 3000 rpm for 30 s. The coating machine was turned on and waited for all the spin coating to be completed to obtain a spin-coated film. Y2, transfer the film spin-coated in step Y1 to a platform furnace at 100°C for pyrolysis for 15 minutes to evaporate and decompose the residual solvent in the film, and allow the film to begin pre-crystallization. Raise the temperature to 150°C, and continue drying for 30 minutes to solidify the film and complete crystallization to obtain a perovskite film.

[0025] Example 3: This example provides a perovskite precursor, which is prepared from the following raw materials in parts by weight: 80 parts of perovskite material, 30 parts of octadecene, 5 parts of diethyl hydroxymethylphosphonate, 5 parts of sodium oleate, 5 parts of acetylacetone, and 8 parts of silicon dioxide nano-oxide; The perovskite material is an ABX3 type perovskite, wherein A is a mixture of methylamine chloride, dimethylamine hydroiodide and phenylethylamine iodine, the mass ratio of the three being 1:1:1, B is GeI4, and X is an iodide ion; The raw materials for preparing the silicon dioxide nano-oxide are silicon dioxide and methyl silicone oil. The preparation method of the silicon dioxide nano-oxide is as follows: weigh silicon dioxide and add it to anhydrous ethanol, perform ultrasonic treatment for 15 minutes, add methyl silicone oil thereto, the amount ratio of silicon dioxide, methyl silicone oil and anhydrous ethanol is 1 g:10 mL:30 mL, react at 50°C for 16 hours, collect the precipitate by centrifugation at 10000 rpm for 10 minutes, wash the precipitate, dry it at a constant temperature of 60°C for 24 hours, and grind it to obtain the silicon dioxide nano-oxide.

[0026] This embodiment also provides a method for preparing a perovskite precursor, which specifically includes the following steps: S1, weigh 80 parts of perovskite material, dissolve it in 30 parts of organic solvent octadecene, stir with a constant temperature stirrer at 500 rpm at 60 °C for 2 h to obtain a solution; S2, adding 5 parts of the additive diethyl hydroxymethylphosphonate to the solution obtained in step S1, stirring at a constant temperature for 1-2 h, stirring at a speed of 300 rpm at 60° C., to obtain a mixed solution; S3, adding 5 parts of surfactant sodium oleate to the mixed solution obtained in step S2, shearing with a high-speed shearing machine at a speed of 15000 rpm, and then ultrasonicating with an ultrasonic cell disruptor for 10 min, with the ultrasonic setting operating state of 5 s on and 5 s off, and the amplitude set to 50%, to obtain a primary emulsion; S4, adding silicon dioxide nano-oxide to the primary emulsion obtained in step S3, and adding 5 parts of stabilizer acetylacetone, and using a high-speed shearing machine at a speed of 12000 rpm, stirring for 5 minutes to emulsify and form an emulsion; S5, sealing and storing the emulsion obtained in step S4 for 6 days to obtain a perovskite precursor.

[0027] In addition, this embodiment further provides a perovskite film, which is prepared from the above-mentioned perovskite precursor. The preparation method of the perovskite film specifically includes the following steps: Y1, will cut into 1 cm 2 The ITO glass substrate was cleaned and dried, fixed on the suction cup of the coating machine, and a drop of the prepared perovskite precursor was dropped on the substrate with a dropper so that the perovskite precursor covered the entire substrate. The speed of the coating machine was set to a low speed of 500 rpm for 10 s and a high speed of 3000 rpm for 30 s. The coating machine was turned on and waited for all the spin coating to be completed to obtain a spin-coated film. Y2, transfer the film spin-coated in step Y1 to a platform furnace at 100°C for pyrolysis for 15 min, evaporate and decompose the residual solvent in the film, and start pre-crystallization of the film, increase the temperature to 150°C, and continue drying for 30 min to solidify the film and complete crystallization to obtain a perovskite film.

[0028] Compared with Example 1, Comparative Example 1 does not include the addition of nano-oxide, and the rest is the same as Example 1.

[0029] The difference between Comparative Example 2 and Example 1 is that the organic solvent is a mixed solvent of DMF and NMP, and the rest is the same as Example 1.

[0030] Comparative Example 3 Compared with Example 1, the preparation method of the perovskite precursor is specifically as follows: mixing the raw materials in parts by weight to form a mixed solution, and stirring the mixed solution at 60° C. for 2 h to obtain a perovskite precursor solution.

[0031] Experimental Example 1: The perovskite precursors prepared in Examples 1-3 and Comparative Examples 1-3 were used to prepare perovskite cells, and the performance of the solar cells was tested. The solar simulator, digital multimeter, and electronic load were calibrated and in good working condition. Under standard test conditions (temperature of 25°C, light intensity of 1000 W / m²), the positive and negative electrodes of the solar cell were connected to the digital multimeter and the electronic load, respectively. When testing the open circuit voltage, the electronic load was disconnected, and the voltage across the battery was measured using a digital multimeter, and the open circuit voltage value was recorded. When testing the short-circuit current, the positive and negative electrodes of the battery were short-circuited, the current in the short-circuit state was measured, and the short-circuit current value was recorded. In addition, the maximum power point on the current-voltage curve can be found by gradually loading the electronic load, the maximum power point voltage and current are recorded, and the fill factor is calculated. During the entire test process, the lighting conditions are kept stable, the contact points are ensured to be clean, and the test is repeated three times to obtain accurate data, the average value is calculated, and the results are recorded in Table 1.

[0032] Experimental Example 2: The PCE (photovoltaic conversion efficiency) of the solar cell prepared by using the perovskite precursors prepared in Examples 1-3 and Comparative Examples 1-3 is measured. The positive electrode of the perovskite solar cell is correctly connected to the solar simulator using a solar simulator. Under light conditions, the external voltage is gradually reduced from the open circuit voltage. The current and voltage are recorded at the same time. The curve is drawn and the PCE is calculated. In order to ensure the accuracy and repeatability of the experimental data, the test should be repeated multiple times and the average value is taken. The average value is recorded in Table 1.

[0033] Table 1

[0034] It can be seen from Table 1 that the photovoltaic device prepared by the perovskite precursor prepared by the method of the present invention shows significant superiority in electrical performance. Specifically, the open circuit voltage and short circuit current of the photovoltaic device are significantly improved, and the filling factor Examples 1-3 are significantly higher than those of Comparative Examples 1-3, indicating that the perovskite precursor prepared by the present invention can improve the efficiency of the device. The photoelectric conversion efficiency of the embodiment reaches 25.6%, which is significantly improved. This result shows that the perovskite precursor provided by the present invention can effectively improve the overall performance of photovoltaic devices.

[0035] Figure 1 No obvious holes were observed in the SEM images, and the grains were intact and not damaged, indicating that no by-products were produced in the perovskite precursor solution. Figure 2 The results show that the contact angle of the perovskite film is higher than that of the control group. This more hydrophobic surface will help improve the humidity stability of perovskite solar cells. Figure 3 The long-term stability of the unpackaged device prepared by the present invention stored in the air for 4000 hours is shown. As can be seen from the figure, the stability of the embodiment can still reach 91% after 4000 hours, indicating that the device prepared by the perovskite precursor prepared by the present invention has good stability.

[0036] In summary, through the verification of the embodiments and comparative examples, it can be known that the present invention adopts Ge4+ to prepare the perovskite precursor in the form of an emulsion, and adds silicon dioxide nano-oxide, additives and stabilizers thereto. The prepared perovskite precursor is not easy to age and has good stability. The perovskite device prepared from the porcelain has good photoelectric properties and stability. The present invention has broad application prospects and important practical significance in the preparation and application of perovskite precursors.

[0037] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A perovskite precursor, characterized in that: The perovskite precursor is prepared from the following raw materials in parts by weight: 50-80 parts of perovskite material, 10-30 parts of organic solvent, 0.1-5 parts of additive, 1-5 parts of surfactant, 0.1-5 parts of stabilizer, and 3-8 parts of nano oxide; The perovskite material is an ABX3 type perovskite, wherein A is one or more of formamidine iodide, methylammonium bromide, methylammonium chloride, dimethylamine hydroiodide and phenylethylamine iodine, B is one or more of GeCl4, GeBr4 and GeI4, and X is an iodide ion or a bromide ion; The organic solvent is one or more of oleic acid, octadecene and oleylamine; The additive is diethyl hydroxymethylphosphonate; The surfactant is one or more of polyvinyl alcohol, sodium dodecyl sulfate and sodium oleate; The stabilizer is acetylacetone; The nano-oxide is silicon dioxide nano-oxide.

2. A perovskite precursor according to claim 1, characterized in that: The raw materials for preparing the silicon dioxide nano-oxide are: silicon dioxide and methyl silicone oil. The preparation method of the silicon dioxide nano-oxide is: weigh silicon dioxide and add it to anhydrous ethanol, ultrasonically treat it for 15 minutes, add methyl silicone oil thereto, react at 50°C for 16 hours, centrifuge at 10000rpm for 10 minutes to collect the precipitate, wash the precipitate, dry it, and grind it to obtain the silicon dioxide nano-oxide.

3. A perovskite precursor according to claim 2, characterized in that: The dosage ratio of silicon dioxide, methyl silicone oil and anhydrous ethanol is 1 g:5-10 mL:30 mL.

4. A method for preparing a perovskite precursor according to any one of claims 1 to 3, characterized in that: The specific steps include: S1, weighing a perovskite material and an organic solvent by weight, dissolving the perovskite material in the organic solvent, and stirring at a constant temperature to obtain a solution; S2, adding additives by weight to the solution obtained in step S1, stirring at a constant temperature for 1-2 h to obtain a mixed solution; S3, adding a surfactant by weight to the mixed solution obtained in step S2 to disperse the mixed solution to obtain a primary emulsion; S4, adding nano-oxide by weight and stabilizer by weight to the primary emulsion obtained in step S3, and emulsifying at high speed to form an emulsion; S5, sealing and storing the emulsion obtained in step S4 for 2-6 days to obtain a perovskite precursor.

5. The method for preparing a perovskite precursor according to claim 4, characterized in that: In step S3, the dispersion is performed using a high-speed shearing machine at a rotation speed of 12000-15000 rpm, and then ultrasonic cell disruptor is used for 10 minutes, the ultrasonic setting operation state is 5 s on and 5 s off, and the amplitude is set to 50%.

6. The method for preparing a perovskite precursor according to claim 4, characterized in that: In step S4, the high-speed shearing is performed using a high-speed shearing machine at a rotation speed of 12,000 rpm for a shearing time of 1-5 min.

7. A perovskite film prepared from the perovskite precursor according to any one of claims 1 to 3, characterized in that: The method for preparing the perovskite film is specifically The following steps are involved: Y1, will cut into 1 cm 2 The ITO glass substrate is cleaned and dried, fixed on the suction cup of the coating machine, and a dropper is used to drop a drop of the prepared perovskite precursor on the substrate so that the perovskite precursor covers the entire substrate. The coating machine is turned on and waits for all the spin coating to be completed to obtain a spin-coated film; Y2, transfer the film spin-coated in step Y1 to a platform furnace at 100°C for pyrolysis for 15 min, evaporate and decompose the residual solvent in the film, and start pre-crystallization of the film, increase the temperature to 150°C, and continue drying for 30 min to solidify the film and complete crystallization to obtain a perovskite film.

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