Perovskite precursor material with high conversion efficiency and preparation method thereof

Abstract

The invention belongs to the technical field of photovoltaic solar materials, and particularly relates to a high-conversion-efficiency perovskite precursor material and a preparation method thereof. The high-conversion-efficiency perovskite precursor material is composed of phenyl ammonium cesium composite cations, metal halide, an additive, a nuclear auxiliary agent and a solvent. By compounding phenylethyl ammonium iodide and cesium iodide, phenylammonium and cesium cations are introduced into perovskite crystal lattices, organic-inorganic balance of the material is optimized, phenylammonium promotes formation of a quasi-two-dimensional structure, and damp-heat stability is enhanced; cesium ions fill A-site gaps, so that crystal lattices are tighter, and the thermal stability and the photoelectric conversion efficiency are improved; the synergistic matching addition of the metal halide realizes band gap regulation and control and spectrum matching, and quaternary ammonium salt adjusts nucleation and grain growth, so that a uniform film structure is ensured, and defects are reduced; and guanidine salt passivates defects after crystal growth, stabilizes crystal lattices, and improves charge life and device efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic solar energy materials, and in particular relates to a high conversion efficiency perovskite precursor material and a preparation method thereof. Background Art

[0002] Perovskite is a material with ABX 3 A compound with a crystal structure, in which the A site is occupied by a larger organic or inorganic cation, the B site is a smaller metal cation (such as lead, tin, etc.), and the X site is filled by a halogen anion (such as chlorine, bromine, iodine, etc.). This type of material is an ideal photoelectric conversion material due to its excellent light absorption performance, long carrier diffusion length, low non-radiative recombination loss and tunable energy band gap, especially suitable for the preparation of high-efficiency solar cells. In the preparation process of perovskite solar cells, the selection of precursor materials plays a crucial role in the quality, crystallinity and photoelectric properties of the final perovskite film. Commonly used perovskite precursor materials include halides containing lead, tin or other metals, such as lead iodide (PbI 2 ), lead bromide (PbBr 2 ), and various organic ammonium salts (such as methylamine iodide, ethylamine iodide, etc.) and their complexes. These precursor materials are converted into high-quality perovskite films through appropriate chemical reactions and physical processes. However, there are some problems in the traditional perovskite precursor preparation process. During the curing and crystallization process, the perovskite precursor is prone to form lattice defects (such as uncoordinated lead ions) and surface defects (such as halogen vacancies). These problems not only increase the non-radiative recombination path, resulting in ineffective loss of charge carriers, but also reduce the photoelectric conversion efficiency of the film. In addition, the high density of defect states will weaken the environmental stability of the perovskite film, causing the device performance to decline rapidly after long-term operation, which greatly limits its practical application potential. Therefore, based on the above problems, it is extremely necessary to develop a perovskite precursor material with high conversion efficiency, safety and reliability. Summary of the invention

[0003] In view of the defects of the prior art, the object of the present invention is to provide a high conversion efficiency perovskite precursor material and a preparation method thereof.

[0004] The technical effect described in the present invention is achieved through the following technical scheme: a high conversion efficiency perovskite precursor material, composed of phenylammonium cesium composite cations, metal halides, additives, nuclear additives and solvents.

[0005] Preferably, the phenylammonium cesium composite cation is prepared by mixing phenylethylammonium iodide and cesium iodide.

[0006] Preferably, the metal halide is one or more of lead iodide, lead bromide, tin iodide and tin bromide.

[0007] Preferably, the additive is a quaternary ammonium salt and a guanidine salt; the quaternary ammonium salt is any one of tetraethylammonium bromide and tetrabutylammonium bromide; the guanidine salt is any one of guanidine iodide, guanidine bromide and guanidine chloride.

[0008] Preferably, the nuclear adjuvant is isopropanol.

[0009] Preferably, the solvent is any one of a mixed solution and γ-butyrolactone; the mixed solution is prepared by mixing N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1.

[0010] Preferably, another aspect of the present invention is to provide a method for preparing a perovskite precursor material with high conversion efficiency, and the specific preparation steps are as follows: S1: Dissolve phenethylammonium iodide and cesium iodide in a solvent respectively, heat to 40-50°C under a nitrogen atmosphere, stir and dissolve evenly, then slowly add the phenethylammonium iodide solution to the cesium iodide solution, continue stirring and mixing at 200 rpm to obtain a composite cationic precursor solution; S2: adding the metal halide to the solvent, preheating and dissolving it at 40-50°C in a nitrogen atmosphere, and then slowly adding it to the composite cationic precursor solution prepared in step S1, and continuing to maintain the temperature at 40-60°C in a nitrogen atmosphere, stirring at 200 rpm to dissolve evenly; S3: adding the quaternary ammonium salt to the solution that has been stirred and dissolved uniformly in step S2, maintaining the nitrogen atmosphere and temperature in step S2, stirring at 200 rpm for 5 to 10 minutes, then adding the guanidine salt, increasing the speed to 400 rpm, and continuing to stir for 5 to 10 minutes to mix uniformly; S4: The mixed solution in step S3 is continuously stirred at 200 rpm for 1 to 2 hours under a nitrogen atmosphere, and filtered through a 0.22 μm filter membrane to obtain a perovskite precursor solution; S5: The perovskite precursor solution prepared in step S4 is dripped onto the conductive glass substrate pretreated with anhydrous ethanol, and spin-coated at a speed of 2000-3000 rpm for 30-60 s. When the spin-coating time is halfway, 300-500 μL / cm 2 After spin coating, annealing is performed at 100 to 140° C. for 20 to 30 minutes to obtain a perovskite precursor material; Preferably, in step S1, the molar ratio of phenethylammonium iodide to cesium iodide is 0.2-0.3:0.7-0.8; the amount of solvent added needs to ensure that the final concentration of the composite cation precursor solution is 1 mol / L; Preferably, in step S1, the specific preparation steps of the phenethylammonium iodide are as follows: A1: Add phenylethylamine to anhydrous ethanol, stir to dissolve evenly, place in an ice bath, then slowly drop 57wt% hydroiodic acid at a rate of 0.5-1mL / min and continue stirring at a speed of 300-500rpm. After the dropwise addition is completed, keep stirring at a speed of 300-500rpm for 30-60min; A2: After the stirring reaction in step A1 is completed, the solvent is removed by a rotary evaporator, the evaporation temperature is controlled at 40-50°C and the rotation speed is 100-150rpm, and then the product is repeatedly washed with cold anhydrous ethanol for 3 times, and then the product is dissolved in anhydrous isopropanol at 50-80°C, slowly stirred and cooled to 0-5°C, filtered, and vacuum dried at 40-50°C for 2-4h to obtain phenethylammonium iodide; Preferably, in step A1, the ratio of the amount of phenethylamine, anhydrous ethanol and hydroiodic acid is 0.1 mol:50 mL:20-25 mL; Preferably, in step A2, the ratio of the amount of anhydrous isopropanol to the product is 5-10 mL: 1 g; Preferably, in step S2, the total molar ratio of the metal halide to the phenethylammonium iodide and cesium iodide in step S1 is 1:1; the ratio of the amount of the metal halide to the solvent is 0.1 mol:120-150 mL; Preferably, in step S3, the amount of the quaternary ammonium salt used is 3-5% of the total moles of the metal at the B site; the amount of the guanidine salt used is 3-5% of the total moles of the metal at the B site.

[0011] The beneficial effects of the present invention are as follows: The present invention can simultaneously introduce two cations, phenylammonium (PhA⁺) and cesium (Cs⁺), into the perovskite lattice by compounding phenylethylammonium iodide (PhAI) with cesium iodide (CsI), thereby effectively balancing the organic-inorganic properties of the material; the introduction of phenylammonium ions tends to form a quasi-two-dimensional structure in the lattice, improving the phase stability and wet heat tolerance of the perovskite material; and cesium ions fill the A-site vacancies, making the lattice structure more compact and improving thermal stability; the reasonable ratio of the two can fine-tune the lattice constant and the energy band structure, avoiding the instability caused by excessive organic components and preventing the lattice distortion caused by the pure inorganic system, thereby achieving a more uniform grain distribution and a smoother carrier transmission path, reducing non-radiative recombination and improving the photoelectric conversion efficiency. In terms of metal halide selection, it can be selected from PbI according to actual needs. 2 、PbBr 2 SnI 2 With SnBr 2Selecting one or more combinations and adding only one metal halide can help to simplify the preparation process and stabilize the material properties. 2 、PbBr 2 SnI 2 With SnBr 2 Flexible combination of different metal halides can achieve precise control of the band gap, effectively optimize the light absorption range to match the solar spectrum, improve the photoelectric conversion efficiency of the device, and reduce the amount of lead used, reduce toxicity, and improve material properties by mixing Pb and Sn; Br ⁻ Partial Replacement I ⁻ The band structure can be further refined and the film crystallization can be promoted, making the perovskite film more uniform and dense, thereby enhancing the environmental stability and device life. Adding an appropriate amount of quaternary ammonium salt during the film formation process can effectively regulate the nucleation and grain growth dynamics of the precursor solution. Quaternary ammonium salts change the surface tension and viscosity of the solution, which helps to achieve uniform nucleation in the phenethylammonium iodide-cesium iodide (PhA-Cs) system, avoid the formation of irregular crystal domains, and promote large grains and orderly arrangement of film structures, reduce surface and grain boundary defects, and improve charge transport and photoelectric conversion performance. At the same time, the addition of guanidine salts can play a role in defect passivation after the crystal growth is completed. The guanidine cation (GA + ) has rich hydrogen bond donor and acceptor properties, which enables it to bind to uncoordinated Pb in the lattice. 2+ / Sn 2+ Ions and halogen vacancies are strongly combined, which effectively reduces the density of deep energy level defects, stabilizes the lattice structure, greatly improves the overall stability and charge life of the perovskite material, and further improves the device efficiency and operating life.

[0012] The present invention independently dissolves PhAI, CsI and metal halide in steps and then slowly mixes them to prevent local supersaturation caused by adding excessive solids at one time, thereby improving the uniformity and stability of the solution. Quaternary ammonium salt is added first and then guanidine salt is added, so as to achieve gradient control of solution physical properties and lattice defect passivation in a hierarchical manner. Quaternary ammonium salt preferentially controls macroscopic crystallization dynamics, and guanidine salt subsequently performs defect passivation, synergistically enhancing the final photoelectric performance of perovskite. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 is a SEM scanning electron microscope image of the perovskite precursor material prepared in Example 2 of the present invention; Figure 2 This is a SEM scanning electron microscope image of the perovskite precursor material prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the raw materials involved in the present invention are purchased through conventional commercial channels.

[0016] Example 1: A high conversion efficiency perovskite precursor material, composed of cesium phenylammonium complex cations, metal halides, additives, nuclear additives and solvents.

[0017] The specific preparation steps of phenethylammonium iodide are as follows: A1: Add 0.1 mol of phenylethylamine to 100 mL of anhydrous ethanol, stir to dissolve evenly, place in an ice bath, then slowly drop 20 mL of 57 wt% hydroiodic acid at a rate of 0.5 mL / min and continue stirring at 300 rpm. After the addition is complete, keep stirring at 300 rpm for 60 min; A2: After the stirring reaction in step A1 is completed, the solvent is removed by a rotary evaporator, the evaporation temperature is controlled at 40°C and the rotation speed is 100 rpm, and then the product is repeatedly washed with cold anhydrous ethanol for 3 times, and then 5 g of the product is dissolved in 50 mL of 50°C anhydrous isopropanol, slowly stirred and cooled to 5°C, filtered, and vacuum dried at 40°C for 2 h to obtain phenethylammonium iodide; The specific preparation steps of perovskite precursor materials are as follows: S1: Dissolve 0.025 mol of phenethylammonium iodide and 0.075 mol of cesium iodide in 50 mL of a mixed solution prepared by mixing N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1, heat to 40°C under a nitrogen atmosphere, stir and dissolve evenly, then slowly add the phenethylammonium iodide solution to the cesium iodide solution, continue stirring and mixing at 200 rpm to obtain a composite cationic precursor solution; S2: Add 0.1 mol of lead iodide to a mixture prepared by mixing 120 mL of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1, preheat and dissolve at 40°C in a nitrogen atmosphere, then slowly add the mixture to the composite cationic precursor solution prepared in step S1, continue to maintain the temperature at 40°C in a nitrogen atmosphere, and stir at 200 rpm to dissolve evenly; S3: Add 0.003 mol of tetraethylammonium bromide to the solution that has been stirred and dissolved uniformly in step S2, maintain the nitrogen atmosphere and temperature in step S2, stir at 200 rpm for 5 minutes, then add 0.003 mol of guanidine iodide, increase the speed to 400 rpm, continue stirring for 5 minutes, and mix uniformly; S4: The mixed solution in step S3 was continuously stirred at 200 rpm for 1 h under a nitrogen atmosphere, and filtered through a 0.22 μm filter membrane to obtain a perovskite precursor solution; S5: The perovskite precursor solution prepared in step S4 is added dropwise onto the conductive glass substrate pretreated with anhydrous ethanol, and spin-coated at a rotation speed of 2000 rpm for 30 seconds. When the spin-coating time is halfway, 300 μL of isopropanol is added dropwise; after spin-coating, anneal at 100° C. for 20 minutes to obtain a perovskite precursor material.

[0018] Example 2: A high conversion efficiency perovskite precursor material, composed of cesium phenylammonium complex cations, metal halides, additives, nuclear additives and solvents.

[0019] The specific preparation steps of phenethylammonium iodide are as follows: A1: Add 0.1 mol of phenylethylamine to 100 mL of anhydrous ethanol, stir to dissolve evenly, place in an ice bath, then slowly add 23 mL of 57 wt% hydroiodic acid at a rate of 0.8 mL / min and continue stirring at 400 rpm. After the addition is complete, maintain the stirring speed at 400 rpm and continue to react for 40 min; A2: After the stirring reaction in step A1 is completed, the solvent is removed by a rotary evaporator, the evaporation temperature is controlled at 45°C and the rotation speed is 120 rpm, and then the product is repeatedly washed with cold anhydrous ethanol for 3 times, and then 5 g of the product is dissolved in 25 mL of anhydrous isopropanol at 60°C, slowly stirred and cooled to 4°C, filtered, and vacuum dried at 45°C for 3 h to obtain phenethylammonium iodide; The specific preparation steps of perovskite precursor materials are as follows: S1: Dissolve 0.03 mol of phenethylammonium iodide and 0.12 mol of cesium iodide in 50 mL of γ-butyrolactone respectively, heat to 45°C under a nitrogen atmosphere, stir and dissolve evenly, then slowly add the phenethylammonium iodide solution to the cesium iodide solution, continue stirring at 200 rpm to mix evenly, and obtain a composite cationic precursor solution; S2: 0.15 mol of lead iodide, lead bromide, tin iodide and tin bromide were added to 150 mL of γ-butyrolactone at a molar ratio of 0.7:0.1:0.1:0.1, preheated to dissolve under a nitrogen atmosphere at 45°C, and then slowly added to the composite cationic precursor solution prepared in step S1, and continued to maintain the temperature at 50°C under a nitrogen atmosphere, and stirred at 200 rpm to dissolve evenly; S3: adding 0.006 mol of guanidine bromide to the solution that has been stirred and dissolved uniformly in step S2, maintaining the nitrogen atmosphere and temperature in step S2, stirring at 200 rpm for 8 min, then adding 0.006 mol of guanidine bromide, increasing the speed to 400 rpm, and continuing to stir for 8 min to mix uniformly; S4: The mixed solution in step S3 was continuously stirred at 200 rpm for 1.5 h under a nitrogen atmosphere, and filtered through a 0.22 μm filter membrane to obtain a perovskite precursor solution; S5: The perovskite precursor solution prepared in step S4 is added dropwise onto the conductive glass substrate pretreated with anhydrous ethanol, and spin-coated at a rotation speed of 2500 rpm for 40 seconds. When the spin-coating time is halfway, 400 μL of isopropanol is added dropwise; after spin-coating, anneal at 130° C. for 25 minutes to obtain a perovskite precursor material.

[0020] Example 3: A high conversion efficiency perovskite precursor material, composed of cesium phenylammonium complex cations, metal halides, additives, nuclear additives and solvents.

[0021] The specific preparation steps of phenethylammonium iodide are as follows: A1: Add 0.1 mol of phenylethylamine to 100 mL of anhydrous ethanol, stir to dissolve evenly, place in an ice bath, then slowly drop 25 mL of 57 wt% hydroiodic acid at a rate of 1 mL / min and continue stirring at a speed of 500 rpm. After the addition is complete, keep stirring at 500 rpm for 30 min; A2: After the stirring reaction in step A1 is completed, the solvent is removed by a rotary evaporator, the evaporation temperature is controlled at 50°C and the rotation speed is 150 rpm, and then the product is repeatedly washed with cold anhydrous ethanol for 3 times, and then 5 g of the product is dissolved in 30 mL of 80°C anhydrous isopropanol, slowly stirred and cooled to 0°C, filtered, and vacuum dried at 50°C for 4 h to obtain phenethylammonium iodide; The specific preparation steps of perovskite precursor materials are as follows: S1: Dissolve 0.036 mol of phenethylammonium iodide and 0.084 mol of cesium iodide in 50 mL of γ-butyrolactone respectively, heat to 50°C under a nitrogen atmosphere, stir and dissolve evenly, then slowly add the phenethylammonium iodide solution to the cesium iodide solution, continue stirring at 200 rpm to mix evenly, and obtain a composite cationic precursor solution; S2: 0.12 mol of lead iodide, lead bromide and tin iodide were added to 150 mL of γ-butyrolactone at a molar ratio of 0.8:0.1:0.1, preheated to dissolve under a nitrogen atmosphere at 50°C, and then slowly added to the composite cationic precursor solution prepared in step S1, and continued to maintain the temperature at 60°C under a nitrogen atmosphere, and stirred at 200 rpm to dissolve evenly; S3: adding 0.006 mol of guanidine bromide to the solution that has been stirred and dissolved uniformly in step S2, maintaining the nitrogen atmosphere and temperature in step S2, stirring at 200 rpm for 10 min, then adding 0.006 mol of guanidine chloride, increasing the speed to 400 rpm, and continuing to stir for 10 min to mix uniformly; S4: The mixed solution in step S3 was stirred at 200 rpm for 2 h under a nitrogen atmosphere, and filtered through a 0.22 μm filter membrane to obtain a perovskite precursor solution; S5: The perovskite precursor solution prepared in step S4 was dripped onto the conductive glass substrate pretreated with anhydrous ethanol, and the solution was spin-coated at a speed of 3000 rpm for 60 s. When the spin-coating time was halfway, 500 μL / cm 2 Isopropanol; after spin coating, annealing is performed at 140°C for 30 minutes to obtain a perovskite precursor material.

[0022] Comparative Example 1: The operation of Comparative Example 1 is substantially the same as that of Example 2, except that no quaternary ammonium salt is added in Comparative Example 1.

[0023] Comparative Example 2: The operation of Comparative Example 2 is substantially the same as that of Example 2, except that no guanidine salt is added in Comparative Example 2.

[0024] Comparative Example 3: The operation of Comparative Example 3 is basically the same as that of Example 2, except that no nuclear auxiliary agent is added in Comparative Example 3.

[0025] Performance Testing: Photoelectric conversion efficiency test: After the precursor materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were deposited on the precursor materials in sequence, a light source simulating sunlight was used at 100 mW / cm 2 The light intensity of (1 sun) was used as the standard for testing, and the test results are shown in Table 1 below.

[0026] Table 1. Photoelectric conversion efficiency of perovskite precursor materials obtained by different raw material ratios and preparation methods

[0027] It can be seen from the results in Table 1 that the perovskite precursor material prepared by the present invention has an excellent photoelectric conversion efficiency, among which the effect of Example 2 is the most outstanding, the effect is significant and the operation is simple, and the use of Br⁻ to partially replace I⁻ further refines the band structure to promote the uniform and dense crystallization of the film, and through the reasonable combination of multi-metal halides, the deficiencies in the absorption range, lattice stability and environmental tolerance are compensated for each other, and the material performance is significantly improved, showing the significant advantages of the raw material ratio and preparation method in the application field of high-efficiency and high-stability perovskite solar cells.

[0028] Figure 1 and Figure 2 The different states of perovskite precursor materials were characterized respectively. Figure 1 Demonstrates the uniformity of the entire surface of the perovskite film. Figure 2 It reflects the microscopic crystal properties of perovskite materials.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high conversion efficiency perovskite precursor material, characterized in that: The invention comprises phenylammonium cesium composite cation, metal halide, additive, nuclear auxiliary agent and solvent; the phenylammonium cesium composite cation is prepared by mixing phenylethylammonium iodide and cesium iodide.

2. The high conversion efficiency perovskite precursor material according to claim 1, characterized in that: The metal halide is one or more of lead iodide, lead bromide, tin iodide and tin bromide.

3. A high conversion efficiency perovskite precursor material according to claim 2, characterized in that: The additives are quaternary ammonium salts and guanidine salts; the quaternary ammonium salts are any one of tetraethylammonium bromide and tetrabutylammonium bromide; the guanidine salts are any one of guanidine iodide, guanidine bromide and guanidine chloride.

4. The high conversion efficiency perovskite precursor material according to claim 3, characterized in that: The solvent is any one of a mixed liquid and gamma-butyrolactone; the mixed liquid is prepared by mixing N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:

1.

5. A method for preparing a high conversion efficiency perovskite precursor material according to any one of claims 1 to 4, characterized in that: The specific preparation steps are as follows: S1: dissolving phenethylammonium iodide and cesium iodide in a solvent respectively, heating under a nitrogen atmosphere, stirring and dissolving uniformly, then slowly adding the phenethylammonium iodide solution to the cesium iodide solution, continuously stirring and mixing uniformly, to obtain a composite cationic precursor solution; S2: adding the metal halide to the solvent, preheating and dissolving it under a nitrogen atmosphere, and then slowly adding it to the composite cationic precursor solution prepared in step S1, continuing to maintain the temperature under a nitrogen atmosphere, stirring and dissolving evenly; S3: adding the quaternary ammonium salt to the solution that has been stirred and dissolved uniformly in step S2, maintaining the nitrogen atmosphere and temperature in step S2, stirring, and then adding the guanidine salt, increasing the speed, and continuing to stir and mix uniformly; S4: Stirring the mixed solution in step S3 under a nitrogen atmosphere, and filtering with a filter membrane to obtain a perovskite precursor solution; S5: dropping the perovskite precursor solution prepared in step S4 onto the conductive glass substrate pretreated with anhydrous ethanol, and spin coating, and adding a nuclear additive when the spin coating time is halfway; annealing treatment is performed after spin coating to obtain a perovskite precursor material.

6. The method for preparing a high conversion efficiency perovskite precursor material according to claim 5, characterized in that: In step S1, the molar ratio of the phenethylammonium iodide to the cesium iodide is 0.2-0.3:0.7-0.8; the amount of the solvent added needs to ensure a final concentration of 1-1.5 mol / L.

7. The method for preparing a high conversion efficiency perovskite precursor material according to claim 6, characterized in that: In step S1, the specific preparation steps of the phenethylammonium iodide are as follows: A1: Add phenylethylamine to anhydrous ethanol, stir to dissolve evenly, place in an ice bath, then slowly drop hydroiodic acid while stirring continuously. After the dropwise addition is complete, continue stirring to react; A2: After the stirring reaction in step A1 is completed, the solvent is removed by a rotary evaporator, and then the product is repeatedly washed with cold anhydrous ethanol. The product is then dissolved in anhydrous isopropanol, slowly stirred and cooled, filtered, and vacuum dried to obtain phenethylammonium iodide.

8. The method for preparing a high conversion efficiency perovskite precursor material according to claim 7, characterized in that: In step A1, the ratio of the amount of phenethylamine, anhydrous ethanol and hydroiodic acid is 0.1 mol:100 mL:20-25 mL; in step A2, the ratio of the amount of anhydrous isopropanol and the product is 5-10 mL:1 g.

9. The method for preparing a high conversion efficiency perovskite precursor material according to claim 8, characterized in that: In step S2, the total molar ratio of the metal halide to phenethylammonium iodide and cesium iodide is 1:1; and the usage ratio of the metal halide to the solvent is 0.1 mol:120-150 mL.

10. The method for preparing a high conversion efficiency perovskite precursor material according to claim 9, characterized in that: In step S3, the amount of the quaternary ammonium salt is 3-5% of the total moles of the metal at the B site; the amount of the guanidine salt is 3-5% of the total moles of the metal at the B site.

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