Method for preparing organic amine lead halide film through metal lead complexing technology

Abstract

The invention discloses a method for preparing an organic amine lead halide film through a metal lead complexing technology, which comprises the following steps of: generating a lead iodide solution with high coordination uniformity in situ in a polar aprotic solvent or a mixed solvent thereof by using metal lead and an iodine simple substance, and depositing a lead iodide film on a conductive glass substrate coated with a charge transport layer, organic amine halide is deposited through a vapor deposition method, and dual control of heterogeneous reaction diffusion kinetics and equilibrium reaction thermodynamics is combined; the ABX3 type perovskite thin film with high quality and high uniformity is successfully prepared, and characterization analysis is carried out through characterization means such as X-ray diffraction spectrogram analysis, a scanning electron microscope and a current density-voltage (J-V) curve under simulated sunlight. According to the technical scheme, the synthesis cost of the organic amine lead halide film is reduced, the stability of the perovskite film is improved, and the photoelectric conversion efficiency of a solar cell prepared from the perovskite film reaches 22.65%.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectric materials, and in particular to a method for preparing an organic amine lead halide film by using a metal lead complexation technology. Background Art

[0002] Over the past decade, organic-inorganic hybrid halide perovskites have attracted widespread attention in the field of next-generation photovoltaics due to their advantages, including low cost, high absorption coefficient, tunable band gap, low defect density, high carrier mobility, and long carrier diffusion length. Notably, the power conversion efficiency (PCE) of perovskite solar cells has rapidly increased from 3.8% to 27%, leading all emerging photovoltaic cells and demonstrating great potential for large-scale commercialization.

[0003] At present, the preparation process flow of perovskite films can be divided into one-step or two-step methods; whether it is a one-step or two-step method in solution or gas phase, the characteristics of the precursor greatly affect the characteristics of the deposited film; and for Pb-based perovskites, PbI6 octahedron is the key component of the perovskite framework, so the Pb source plays an important role in determining the crystallization, structure and optoelectronic properties of perovskite films.

[0004] At present, the one-step or two-step method mainly uses metal halide lead iodide (PbI2) to prepare the perovskite work absorption layer; Seok et al. used a one-step solution method to form a coherent intermediate layer between a Cl-containing FAPbI3 precursor solution and a tin oxide electrode to produce a perovskite solar cell with a functional conversion efficiency of 25.8% (certified as 25.5%); You et al. used a two-step solution method to dope rubidium chloride (RbCl) in the PbI2 solution to convert excess PbI2 into an inactive, new secondary phase (PbI2)2RbCl to stabilize the perovskite, and prepared a perovskite solar cell with an efficiency of 26.1% (certified as 25.6%); Yi et al. reported a two-step sequential deposition method of solution deposition of cesium bromide (CsBr), lead chloride (PbCl2) and PbI2 thin films, followed by vapor deposition of FAI and annealing, and they prepared a PCE of up to 24.1%0.1cm 2 The device, the unpackaged evaporation device has good stability; similarly, they combined the multifunctional hole transport material with the perovskite prepared by sequential evaporation to make the 0.1 and 1.0 cm 2The power conversion efficiency of the PSCs reached 26.41% (26.21% certified) and 24.88% (certified), respectively. Due to the rapid Lewis acid-base reaction between PbI2 and MA(FA)I, and the rapid crystallization rate of MA(FA)PbI3, it is difficult to prepare high-quality perovskite films using one-step solution or two-step sequential deposition techniques. These techniques require regulation through various means, including additive engineering and solvent engineering. Furthermore, the one-step or two-step methods place extremely high demands on lead iodide, requiring both high purity and good solubility, which significantly increases commercialization costs.

[0005] Using only PbCl2 as the B-site source of perovskite is still far behind lead iodide, and is also highly dependent on the purity of metal halide, while requiring additional consumption of organic iodinated amines. The development of using other lead-based compounds, such as lead acetate, lead acetate hydrate, lead nitrate, lead thiocyanate, monovalent lead oxide, lead oxide, and lead sulfide as lead sources to prepare perovskites, whether one-step or two-step methods, is currently far behind the progress of lead iodide and cannot replace PbI2.

[0006] It is worth noting that the scalable deposition method and low price of metallic lead thin films make them a more suitable lead source than other lead-based compounds. Zhou et al. converted the electrodeposited lead film into MAPbI3 thin film by electric field-assisted chemical reaction in MAI solution at 0.15 cm 2 A PCE of 15.65% was obtained on the device; Tavakoli et al. used chemical vapor deposition (CVD) technology to expose the thermally evaporated metal lead film to MAI atmosphere to prepare a MAPbI3 perovskite film and obtained a PSC device with a PCE of 14.21%. However, the use of electric field or CVD equipment greatly increases the cost of this method. Turkevych et al. reported a thermally evaporated metal lead / MAI (FAIor CsI) double-layer film, which produced polyiodide under the action of iodine vapor to directly oxidize Pb 0 The MAPbI3 thin film produced achieved a PCE of 17.18% in a small-area PSC. The above methods using lead metals are not easy to process as solution methods and require high production equipment, increasing commercialization costs.

[0007] In summary, the existing technology mainly has the following problems:

[0008] 1. Due to the rapid Lewis acid-base reaction between PbI2 and MA(FA)I, it is difficult to prepare high-quality perovskite films using one-step solution or two-step sequential deposition techniques. This requires regulation through various means such as additive engineering and solvent engineering.

[0009] 2. The one-step or two-step solution method has extremely high requirements for PbI2, requiring both high purity and good solubility, and puts higher demands on the production, storage, and transportation of PbI2, which greatly increases the commercialization cost;

[0010] 3. The one-step or two-step vapor phase method requires vacuum deposition equipment, which places high demands on production equipment and is not conducive to large-scale commercialization;

[0011] 4. Currently, it is difficult to prepare high-performance organic amine lead halide films using a solution process using metallic lead as the lead source. Summary of the Invention

[0012] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for preparing an organic amine lead halide thin film by metal lead complexation technology.

[0013] The present invention provides a method for preparing an organic amine lead halide film by metal lead complexation technology, which uses raw materials such as metal lead, iodine and an organic amine halide salt to prepare the organic amine lead halide film by metal lead complexation technology, comprising the following steps:

[0014] 1) Pre-treating the metallic lead to obtain metallic lead with a bright surface;

[0015] 2) dissolving metallic lead and elemental iodine in a polar aprotic solvent, stirring and allowing them to fully react to obtain a first intermediate product reaction solution;

[0016] 3) adding a certain amount of alkali metal halide to the first intermediate product reaction liquid according to actual needs and stirring uniformly to obtain a second intermediate product reaction liquid;

[0017] 4) heating and stirring the second intermediate product reaction solution at 45-100° C. to further dissolve it, and then performing precipitation filtration or centrifugation to obtain a clear coordinated lead organic solution;

[0018] 5) depositing the coordinated lead organic solution to obtain a solid film, and selecting a suitable organic amine halide salt according to actual needs;

[0019] 6) placing the solid film and an organic amine halide salt together in a low vacuum gas-solidification reaction device for reaction; wherein the organic amine halide salt is sprayed on a transparent upper substrate in the low vacuum gas-solidification reaction device, and the solid film is placed on a lower substrate in the low vacuum gas-solidification reaction device;

[0020] 7) performing a sublimation stage, heating the upper substrate while the lower substrate is not heated, and depositing the organic amine halide salt on the solid film;

[0021] 8) The upper substrate and the lower substrate are simultaneously heated to 110-130° C. for reaction, and the grain nucleation and growth stage is performed. After the reaction is completed, the heating is stopped, and the successfully prepared organic amine lead halide film is taken out.

[0022] Furthermore, in step 1), the metal lead is pretreated by polishing and cleaning the metal lead to remove its surface oxide layer.

[0023] Furthermore, the polar aprotic solvent in step 2) is a mixed solvent of one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone or 1,3-dimethyl-2-imidazolidinone.

[0024] Furthermore, the purity of the iodine element in step 2) is 98% to 99.999%; the purity of the metallic lead is 99% to 99.999%, and the coarseness is higher than 0.22 μm.

[0025] Furthermore, the molar ratio of the metallic lead to elemental iodine in step 2) is set to between 1.01 and 1.1:1.

[0026] Furthermore, the first intermediate product reaction solution in step 2) is prepared by directly mixing the metallic lead and elemental iodine in the polar aprotic solvent according to the molar ratio of the substances, and stirring for 1-12 hours under light-proof conditions.

[0027] Furthermore, the first intermediate product reaction solution in step 2) is prepared by pre-dissolving the elemental iodine in the polar aprotic solvent to obtain an iodine organic solution, and then adding the metallic lead to the iodine organic solution, heating, stirring, and reacting for 1-10 hours.

[0028] Furthermore, in step 5), the method of depositing the coordinated lead organic solution to obtain a solid film includes spin coating, blade coating, inkjet printing or pulling.

[0029] Furthermore, the organic amine halide salt is a mixture of one or more of methylamine halide or formamidine halide formed by the reaction of methylamine, formamidine acetate and hydrohalic acid.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The method of preparing an organic amine lead halide thin film by metal lead complexation technology of the present invention has a simple preparation process and precise control. The raw materials are readily available and inexpensive. The cost is much lower than the current mainstream raw material lead iodide, thereby reducing the synthesis cost of the organic amine lead halide thin film.

[0032] The coordinated lead organic colloid synthesized using metallic lead as the lead source in the present invention has uniform micelles and the precursor film prepared is in an amorphous state, which successfully promotes the diffusion of organic amine halide salt to the bottom of the film and improves the stability of the perovskite film.

[0033] The invention can be applied to the preparation of organic halide solar cells, and an organic amine metal halide solar cell is prepared, and the photoelectric conversion efficiency reaches 22.65%.

[0034] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 This is a diagram of the preparation process of the organic amine lead halide film of the present invention;

[0037] Figure 2 An X-ray diffraction spectrum for analyzing and characterizing the precursor film deposited in step 5 of the present invention;

[0038] Figure 3 A scanning electron microscope (SEM) characterization image of the precursor film deposited in step 5 of the present invention;

[0039] Figure 4 The scanning electron microscope (SEM) characterization images are obtained by analyzing and characterizing the surface of the organic amine lead halide film and the cross section of the optoelectronic device of the present invention;

[0040] Figure 5 X-ray diffraction spectrum for analyzing and characterizing the organic amine lead halide film prepared by the present invention;

[0041] Figure 6 A current density-voltage (JV) curve of a device used in a solar cell under simulated sunlight, obtained by analyzing and characterizing the prepared product provided in Example 1 of the present invention;

[0042] Figure 7 X-ray diffraction spectrum of the organic amine lead halide thin film prepared for analysis and characterization in Example 2;

[0043] Figure 8 A current density-voltage (JV) curve of a device used in a solar cell under simulated sunlight, obtained by analyzing and characterizing the prepared product provided in Example 2;

[0044] Figure 9 X-ray diffraction spectrum of the organic amine lead halide thin film prepared for analysis and characterization in Example 3;

[0045] Figure 10 A current density-voltage (JV) curve of a device used in a solar cell under simulated sunlight, obtained by analyzing and characterizing the prepared product provided in Example 3;

[0046] Figure 11 The figure is a flow chart for preparing the organic amine lead halide film of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The invention uses metallic lead as a raw material and designs a metallic lead complexation technology to prepare an organic amine lead halide film with high conversion rate and low defect density.

[0050] refer to Figure 1-11 The embodiment of the present invention provides a method for preparing an organic amine lead halide thin film by metal lead complexation technology, wherein the organic amine lead halide thin film is prepared by metal lead complexation technology using raw materials such as metal lead, iodine and organic amine halide salt, including the following steps:

[0051] 1) pre-treating the metallic lead to obtain metallic lead with a bright surface, and preparing the pre-treated metallic lead into metallic lead;

[0052] The method of pre-treating the metal lead is to polish and clean the metal lead to remove the surface oxide layer;

[0053] 2) dissolving metallic lead and elemental iodine in a polar aprotic solvent, stirring and allowing them to fully react to obtain a first intermediate product reaction solution;

[0054] Preferably, the polar aprotic solvent is a mixed solvent of one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone or 1,3-dimethyl-2-imidazolidinone;

[0055] Most preferably, the polar aprotic solvent is a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), with the optimized amount being DMSO:DMF (v:v) = 1.1:8.9;

[0056] The purity of iodine is 98% to 99.999%; the purity of lead metal is 99% to 99.999%, and the coarseness is higher than 0.22μm;

[0057] There are two ways to prepare the first intermediate product reaction solution:

[0058] Method 1: directly mixing metallic lead and elemental iodine in a polar aprotic solvent according to the molar ratio, and stirring for 1-12 hours under light-proof conditions;

[0059] Method 2: Dissolve elemental iodine in a polar aprotic solvent or a mixed solvent thereof to obtain an iodine organic solution, then add metallic lead to the iodine organic solution, heat, stir, and react for 1-10 hours;

[0060] The molar ratio of the above-mentioned metallic lead to elemental iodine is set between 1.01 and 1.1:1 to ensure that the iodine reacts fully and a small amount of Pb remains. 0 Inhibit the aging of lead iodide solution and the precipitation of iodine;

[0061] 3) adding a certain amount of alkali metal halide to the first intermediate product reaction liquid according to actual needs and stirring evenly to obtain a second intermediate product reaction liquid;

[0062] 4) heating and stirring the second intermediate product reaction solution at 45-100° C. to further dissolve it, and then performing precipitation filtration or centrifugation to obtain a clear coordinated lead organic solution;

[0063] Lead is removed by precipitation filtration or centrifugation. Even if it passes through the filter membrane, tiny lead clusters remain, which are converted into organic amine lead halides in subsequent reactions.

[0064] 5) preparing a solid film (precursor film) from the coordinated lead organic solution by spin coating, doctor blade coating, inkjet printing or pulling deposition, and selecting a suitable organic amine halide salt according to actual needs;

[0065] Among them, the precursor film formed by solution coating such as spin coating or doctor blade coating is in a strong amorphous state, and the subsequent reaction is conducive to the conversion to organic amine lead iodide;

[0066] Preferably, the organic amine halide salt is a mixture of one or more of methylamine halide or formamidine halide formed by the reaction of methylamine, formamidine acetate and hydrohalic acid;

[0067] 6) placing the solid film and the organic amine halide salt together in a low vacuum gas-solidification reaction device for reaction; wherein the organic amine halide salt is sprayed on a transparent upper substrate in the low vacuum gas-solidification reaction device, and the solid film is placed on a lower substrate in the low vacuum gas-solidification reaction device;

[0068] 7) performing a sublimation stage, wherein the upper substrate is heated to 110-130° C. using a stepwise heating method without heating the lower substrate, and the organic amine halide salt is uniformly deposited on the solid film until the surface of the solid film appears colored due to refraction of visible light by the deposited organic amine halide salt; wherein the amount of organic amine halide salt deposited depends on the thickness of the precursor film;

[0069] 8) The upper substrate and the lower substrate are heated simultaneously, and the (curved) solid film and the organic amine halide salt powder are heated together to 110-130° C. for reaction for 30-50 minutes to enter the grain nucleation growth stage; after the reaction is completed, the heating is stopped and the successfully prepared organic amine lead halide film is taken out; the organic amine lead halide film includes CH3NH3PbI3 or NH2CHNH2PbI3 with high conversion rate and low defect density.

[0070] Through the above technical solution, lead as a raw material is converted into high-quality organic amine lead halide film through polar aprotic solvent complexation. The process is highly operable. More importantly, it can significantly reduce the manufacturing cost of organic amine lead halide. The use of this technology to manufacture perovskite light-absorbing layers can further reduce photovoltaic electricity prices and is expected to be expanded to the raw material engineering of perovskite optoelectronic devices.

[0071] The crystal structure and particles of the organic amine lead halide are analyzed and characterized using X-ray diffraction analysis or scanning electron microscopy. In addition, the photoelectric conversion efficiency of the organic amine lead halide film can be characterized and analyzed based on the current density-voltage (JV) curve characteristics of the organic lead halide film under simulated sunlight.

[0072] like Figure 1 As shown, the present invention provides a principle flow chart of a method for preparing a curved organic amine lead halide perovskite film with high conversion rate and low defect density using a vapor phase method relying on solvent complexation. The first step is the synthesis of the precursor solution, the second step is the pre-deposition of the precursor film, the third step is the organic halide diffusion process (low vacuum vapor phase reaction), and the fourth step is to obtain a high-quality (curved) organic amine lead halide perovskite film.

[0073] The present invention aims to solve the following drawbacks in the prior art: the solution is prepared by dissolving metal halide powder or particles, the micelles are uneven, the film crystallinity is high after film formation, and the conversion rate of metal halide to perovskite is low;

[0074] The present invention provides a method for preparing an organic amine lead halide film with high conversion rate and low defect density by using a coordinated lead organic precursor solution;

[0075] Specific embodiment 1 is as follows:

[0076] 1) Metallic lead and iodine were dissolved in a mixed solvent of DMSO:DMF (V:V) = 1.1:8.9 at a molar ratio of 1.01:1 and stirred thoroughly to react, thereby synthesizing a 1.55 M lead iodide solution in situ. The solution was then stirred at 60° C. for 2 hours, and the solution was precipitated, filtered, or centrifuged before use.

[0077] 2) The ITO substrate was cleaned and treated with UV / ozone for 15 minutes. Then, a MeO-4PACZ (SAM) solution dissolved in anhydrous ethanol was spin-coated, followed by rinsing with anhydrous ethanol and annealing at 100°C for 10 minutes.

[0078] 3) Deposit the precursor film on the ITO substrate by spin coating at 4000 rpm for 30 seconds;

[0079] 4) Spraying FAI onto a flat transparent upper substrate as an FAI evaporation source; placing the precursor film upward on the lower substrate; placing the upper substrate downward on top of the precursor film, and using close-range CVD to react and prepare perovskite; the distance between the FAI evaporation source and the precursor film is 0.8-1 cm, the vacuum degree is 300-800 Pa, the curved heating plate and the FAI evaporation source are heated to 110-130°C, and the reaction time is 30-50 minutes;

[0080] 5) After the reaction is completed, heating is stopped, the device is inflated, the prepared NH2CHNH2PbI3 film is taken out, and C 60 , BCP, Ag, the evaporation rates are 2nm / s, 0.1nm / s, 10nm / s, and the thicknesses are 22nm, 8nm, 100nm, respectively.

[0081] Figure 2 This is an X-ray diffraction spectrum of the precursor film deposited in Example 1. The absence of diffraction peaks in the spectrum indicates that the deposited film is amorphous and has low crystallinity. The irregular, loose, and porous structure is conducive to the diffusion of organic amine halides.

[0082] Figure 3 This is a scanning electron microscope (SEM) image of the precursor film deposited in Example 1. This photo shows the morphology after annealing and solvent evaporation. The lamellar structure formed by the micelles is relatively uniform.

[0083] Figure 4Scanning electron microscope (SEM) characterization images of the surface and cross-section of the organic amine lead halide film of Example 1; the resulting NH2CHNH2PbI3 film is mainly composed of large particles with large and uniform particle size; the right figure shows that the resulting NH2CHNH2PbI3 film has grains that run vertically and are uniform in size;

[0084] Figure 5 The X-ray diffraction spectrum of the organic amine lead halide film prepared in Example 1 was analyzed and characterized by an instrument. The figure shows that the PbI2 peak does not appear, and almost all of it is converted into NH2CHNH2PbI3, indicating that the present invention can achieve complete conversion of lead into organic amine lead halide film.

[0085] Figure 6 The current density-voltage (JV) curve of the device used in the solar cell under simulated sunlight for analyzing and characterizing the prepared product provided in Example 1; the battery (ITO / SAM / NH2CHNH2PbI3 / C 60 / BCP / Ag) has a functional conversion efficiency of 22.65%, indicating that this method is effective in preparing high-performance perovskite solar cells.

[0086] Specific embodiment 2 is as follows:

[0087] Preparation of CH3NH3PbI3 solution from lead iodide colloid synthesized from metallic lead, and preparation of thin films and batteries by anti-solvent method:

[0088] 1) Metallic lead and iodine were dissolved in a DMSO:DMF (V:V) mixed solvent of 1:4 at a molar ratio of 1.01:1 and stirred thoroughly to react, thereby synthesizing a 1.5 M lead iodide solution in situ. The solution was then stirred at 60° C. for 2 hours, and the solution was precipitated and filtered or centrifuged before use.

[0089] 2) Add 0.238 g of MAI to 1 mL of the above solution and stir at 65°C for 2 hours to obtain a CH3NH3PbI3 solution;

[0090] 3) Drop 50 μL of CH3NH3PbI3 solution on the center of the substrate (ITO / SAM), and then use a one-step spin coating procedure at 4000 rpm for 30 s with an acceleration of 1000 rpm·s -1 20 seconds before the end of the spin coating process, ethyl acetate was quickly dropped on the surface of the rotating substrate. Immediately after the spin coating was completed, the substrate was placed on a hot plate at 100°C and annealed for 10 minutes to obtain a CH3NH3PbI3 film.

[0091] 4) Prepare C on CH3NH3PbI3 film 60, BCP, Ag, the evaporation rates are 2nm / s, 0.1nm / s, 10nm / s, and the thicknesses are 22nm, 8nm, 100nm, respectively.

[0092] Figure 7 X-ray diffraction spectrum of the organic amine lead halide film prepared in Example 2 for analysis and characterization; the figure shows that: the PbI2 peak does not appear, and CH3NH3PbI3 is generated; this shows that the method for synthesizing the lead iodide precursor solution of the present invention can be used to prepare a thin film using anti-solvent processing;

[0093] Figure 8 This is a current density-voltage (JV) curve of a device used in a solar cell under simulated sunlight, which is obtained by analyzing and characterizing the prepared product provided in Example 2;

[0094] Specific embodiment 3 is as follows:

[0095] Preparation of MA from metal halide colloids synthesized from lead and tin powders 0.5 FA 0.5 Pb 0.5 Sn 0.5 I3 solution, anti-solvent method for preparing thin films and batteries:

[0096] 1) Metallic lead and tin powders were dissolved with iodine in a DMSO:DMF (V:V) mixed solvent of 1:4 at a molar ratio of 1.01:1 and stirred thoroughly to synthesize 1.5 M lead iodide and stannous iodide solutions in situ. The mixture was then stirred at 60°C for 2 hours, and the solution was precipitated and filtered or centrifuged before use.

[0097] 2) Add 0.238 g MAI to 1 mL of the above lead iodide solution, and add 0.258 g FAI to 1 mL of the above stannous iodide solution, and stir at 60°C for 2 hours;

[0098] 3) Mix the two solutions obtained in 2) at a ratio of 1:1, stir at 60°C for 0.5 h, and drop 50 μL of the mixed solution onto the center of the substrate (ITO / PEDOT:PSS);

[0099] 4) Then a two-step spin coating procedure was used, with the first step being 1000 rpm for 10 s and an acceleration of 200 rpm·s -1 , second step 4000 rpm, 40s, acceleration 1000 rpm·s -1 , 20s before the end of the spin coating process, quickly drop ethyl acetate on the surface of the rotating substrate. Immediately after the spin coating is completed, the substrate is placed on a hot plate at 100°C for annealing for 10min;

[0100] 5) Prepare C on CH3NH3PbI3 film 60, BCP, Ag, the evaporation rates are 2nm / s, 0.1nm / s, 10nm / s, and the thicknesses are 22nm, 8nm, 100nm, respectively.

[0101] Figure 9 X-ray diffraction spectrum of the organic amine lead halide thin film prepared in Example 3 for analysis and characterization; the figure shows that the PbI2 and SnI2 peaks are absent, indicating that the method for synthesizing the metal halide precursor solution of the present invention can be used to prepare thin films using anti-solvent processing;

[0102] Figure 10 This is a current density-voltage (JV) curve of a device used in a solar cell under simulated sunlight, which is provided in Example 3 for analyzing and characterizing the prepared product.

[0103] In this specification, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0104] Throughout this specification, terms such as "one embodiment" or "some embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0105] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing an organic amine lead halide thin film by metal lead complexation technology, characterized in that: The organic amine lead halide film is prepared by using raw materials such as metallic lead, iodine and organic amine halide salt through a metallic lead complexation technology, which includes the following steps: 1) Pre-treating the metallic lead to obtain metallic lead with a bright surface; 2) dissolving metallic lead and elemental iodine in a polar aprotic solvent, stirring and allowing them to fully react to obtain a first intermediate product reaction solution; 3) adding a certain amount of alkali metal halide to the first intermediate product reaction liquid according to actual needs and stirring uniformly to obtain a second intermediate product reaction liquid; 4) heating and stirring the second intermediate product reaction solution at 45-100° C. to further dissolve it, and then performing precipitation filtration or centrifugation to obtain a clear coordinated lead organic solution; 5) depositing the coordinated lead organic solution to obtain a solid film, and selecting a suitable organic amine halide salt according to actual needs; 6) placing the solid film and an organic amine halide salt together in a low vacuum gas-solidification reaction device for reaction; wherein the organic amine halide salt is sprayed on a transparent upper substrate in the low vacuum gas-solidification reaction device, and the solid film is placed on a lower substrate in the low vacuum gas-solidification reaction device; 7) performing a sublimation stage, heating the upper substrate while the lower substrate is not heated, and depositing the organic amine halide salt on the solid film; 8) The upper substrate and the lower substrate are simultaneously heated to 110-130° C. for reaction, and the grain nucleation and growth stage is performed. After the reaction is completed, the heating is stopped, and the successfully prepared organic amine lead halide film is taken out.

2. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 1, characterized in that: The method of pre-treating the metal lead in step 1) is to polish and clean the metal lead to remove the surface oxide layer.

3. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 1, characterized in that: The polar aprotic solvent in step 2) is a mixed solvent of one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone or 1,3-dimethyl-2-imidazolidinone.

4. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 1, characterized in that: The purity of the iodine element in step 2) is 98% to 99.999%; the purity of the metallic lead is 99% to 99.999%, and the coarseness is higher than 0.22 μm.

5. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 4, characterized in that: The molar ratio of the metallic lead to elemental iodine in step 2) is set between 1.01 and 1.1:

1.

6. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 5, characterized in that: The first intermediate product reaction solution in step 2) is prepared by directly mixing the metallic lead and elemental iodine in the polar aprotic solvent according to the molar ratio of the substances, and stirring for 1-12 hours under light-proof conditions.

7. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 5, characterized in that: The first intermediate product reaction solution in step 2) is prepared by pre-dissolving the elemental iodine in the polar aprotic solvent to obtain an iodine organic solution, then adding the metallic lead to the iodine organic solution, heating, stirring, and reacting for 1-10 hours.

8. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 1, characterized in that: In step 5), the method of depositing the coordinated lead organic solution to obtain a solid film includes spin coating, blade coating, inkjet printing or pulling.

9. The method for preparing an organic amine lead halide thin film by metal lead complexation technology according to claim 1, characterized in that: The organic amine halide salt is a mixture of one or more of methylamine halide or formamidine halide formed by the reaction of methylamine, formamidine acetate and hydrohalic acid.

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