Perovskite nanocage material and preparation method thereof
By adding aids with vacancy formation and diffusion functions to the perovskite nanocrystal synthesis reaction system, high-quality perovskite nanocage materials are prepared by using the nucleation growth synthesis reaction method, which solves the problems of synthesis of perovskite nanocage materials and the problems of insufficient stability, and achieves high controllability and long-term application of the materials.
Patent Information
- Application Number
- CN202510111618.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-05-13
AI Technical Summary
The prior art is difficult to control the synthesis of perovskite nanocage materials in perovskite systems, and the materials have poor stability in severe environments.
By adding additives with vacancy formation and diffusion functions to the synthesis reaction system of perovskite nanocrystals to form a mixture, the perovskite nanocage material with high repeatability and consistency is prepared by using the nucleation and growth synthesis reaction method.
It realizes high controllable synthesis of perovskite nanocage materials, enhances the chemical stability and environmental tolerance of the materials, and is suitable for long-term applications of optoelectronic devices.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of nanotechnology, and specifically relates to a perovskite nanocage material and a preparation method thereof. Background Art
[0002] Perovskite nanocrystals or quantum dots have unique photophysical properties due to their size effect and are favored in a variety of optoelectronic technologies, including solar cells, light-emitting diodes, lasers, and luminescent solar concentrators. Compared with bulk perovskites, perovskite nanocrystals are widely used in high-performance light-harvesting and light-source devices due to their multi-exciton effect, high photoluminescence quantum efficiency, and optical properties that can be regulated by surface engineering. In addition, due to their high defect tolerance, perovskite nanocrystals can achieve high luminescence intensity and excellent optoelectronic properties without the complex core-shell structure of traditional nanocrystal materials.
[0003] At present, most of the research is devoted to synthesizing perovskite nanocrystals with controllable morphologies, such as nanocrystal cubes, nanorods, nanowires and nanosheets. As a nanomaterial with a unique hollow inner cavity structure, as well as morphological and structural characteristics such as adjustable size, wall thickness and surface properties, nanocages have great application prospects in the fields of biomedicine, catalysis, optoelectronics, etc. However, few people have studied perovskite nanocage materials.
[0004] The main methods for synthesizing nanocage materials include Kirkendall effect, Oswald ripening, electrochemical replacement, cation exchange, etc. However, unlike traditional semiconductors, perovskite exhibits certain ionic properties. Since perovskite has a soft, ionic crystal structure, it is difficult to maintain its crystal structure in harsh environments. The existing method for synthesizing hollow nanocages is difficult to apply in perovskite systems. Therefore, finding a suitable method for controllable synthesis of perovskite nanocages is of great significance for obtaining high-quality perovskite nanocrystalline films and further applications of perovskite materials. Summary of the invention
[0005] The purpose of the present invention is to provide a novel perovskite nanocage material with high repeatability and a preparation method thereof by utilizing vacancy formation and diffusion functional additives in view of the blank of the controllable synthesis of the existing perovskite nanocage material.
[0006] The technical solution for achieving the purpose of the present invention provides a method for preparing a perovskite quantum dot material, wherein an auxiliary agent having vacancy formation and diffusion functions, or an organic metal salt compound auxiliary agent having both vacancy formation and diffusion functions is added to a synthetic reaction system of perovskite nanocrystals to form a mixture, thereby obtaining a perovskite nanocage reaction system; and a perovskite nanocage material is obtained through a nucleation growth synthesis reaction. The structure of the perovskite is ABX3, where A is Cs +, CH(NH2)2 + or CH3NH3 + , B is Pb 2+ , Sn 2+ or Yb 2+ , X is I - , Cl - or Br - ; The auxiliary agent having the function of forming vacancies has the structural formula: , , , One or more of, wherein n is the number of carbon atoms, n=1-5; X is one of a mercapto group, a phosphino group, an ammonium group, a carboxyl group or a sulfonic acid group; The auxiliary agent with diffusion function includes a cation or anion metal salt, or an organic molecule, whose ion radius is smaller than that of the perovskite.
[0007] The metal salts described in the present invention include sodium salts, magnesium salts and potassium salts.
[0008] The structure of the organic molecule is: , Wherein, n is the number of carbon atoms, n=1-8; X is one of a mercapto group, a phosphino group, an ammonium group, a carboxyl group or a sulfonic acid group.
[0009] The organic metal salt compound auxiliary agent having both vacancy formation and diffusion functions includes sodium benzene sulfonate, dibenzyl potassium phosphate, dibenzyl sodium carbon dithiophosphate, sodium benzylphosphonate, sodium phenylacetate, and potassium phenylacetate.
[0010] In the perovskite nanocage reaction system, the molar ratio of the auxiliary agent with vacancy formation function to the A-site cation of the perovskite structure is 0.2-5; the molar ratio of the auxiliary agent with diffusion function to the A-site cation of the perovskite structure is 0.2-10.
[0011] The preparation method of the perovskite nanocage material described in the present invention comprises a nucleation growth synthesis reaction method including a hot injection method, a reprecipitation method, a chemical vapor deposition method, a ball milling method, a probe ultrasound method and a microwave radiation method.
[0012] The technical solution of the present invention also includes a perovskite nanocage material obtained according to the above preparation method, which has a cavity structure.
[0013] The size of the perovskite nanocage provided by the invention is 5-100 nm; the cavity size of the perovskite nanocage is 1-80 nm; and its fluorescence emission peak is 300-900 nm.
[0014] The principle of the present invention is: in the synthesis process of perovskite nanocages, an auxiliary agent with vacancy formation and diffusion functions is used. The role of the vacancy forming agent is to introduce vacancies in the crystal. These vacancies, as structural defects, provide favorable conditions for the formation of hollow nanocrystals; and the diffusing agent promotes the diffusion of these vacancies in the reaction system, further affecting the growth process of the crystal. Specifically, the vacancy forming agent breaks the integrity of the crystal by introducing vacancies in the crystal structure, and these vacancies accumulate in the perovskite nanocrystals. In this process, due to the presence of vacancies, the reactant molecules are no longer arranged according to traditional rules, but tend to form an incompletely filled structure. The diffusing agent accelerates the diffusion of these vacancies, prompting the vacancies to expand along the growth direction of the crystal to form a structure with hollow characteristics. In the nucleation growth process, the diffusion and local accumulation of vacancies cause the crystals of the perovskite material to form a hollow structure at the nanoscale, and finally generate perovskite nanocrystals with a hollow morphology. The special morphology of these nanocrystals enables them to show unique advantages in terms of optoelectronic properties and the like. Therefore, the vacancy formers generate vacancies and affect the nucleation process, while the diffusors promote the diffusion of vacancies, which ultimately leads to the formation of perovskite nanocages with hollow morphology. The synergistic effect of the two provides a new approach for the synthesis of perovskite nanocages.
[0015] Compared with the prior art, the technical solution of the present invention has the following significant effects: 1. Improve the controllable synthesis of materials: By introducing vacancy formers and diffusants, the present invention realizes the controllable synthesis of perovskite nanocage materials in terms of size, morphology and composition, filling the gap in the precise control of traditional methods.
[0016] 2. Enhanced material stability: The synergistic effect of vacancy formers and diffusers effectively reduces lattice defects and inhomogeneities, significantly improving the chemical stability and environmental tolerance of perovskite nanocage materials, making them more suitable for long-term applications in optoelectronic devices.
[0017] 3. High repeatability and consistency: The preparation method proposed in the present invention enables the perovskite nanocage material to have high repeatability and consistency in large-scale production, overcoming the limitations of the prior art in batch stability and providing the possibility for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 , 2 They are respectively a transmission electron microscope image and a steady-state fluorescence spectrum of the perovskite nanocage material prepared in Example 1 of the present invention; Figure 3 , 4 They are respectively a transmission electron microscope image and a steady-state fluorescence spectrum of the perovskite nanocage material prepared in Example 2 of the present invention; Figure 5, 6 They are respectively a transmission electron microscope image and a steady-state fluorescence spectrum of the perovskite nanocage material prepared in Example 3 of the present invention; Figure 7 , 8 They are respectively a transmission electron microscope image and a steady-state fluorescence spectrum of the perovskite nanocage material prepared in Example 4 of the present invention; Fig. 9 This is a transmission electron microscope image of the perovskite nanocage material prepared in Example 5 of the present invention. DETAILED DESCRIPTION
[0019] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. Example 1
[0020] This embodiment provides a FAPbI3 perovskite nanocage material synthesized based on a hot injection method, and its preparation method and specific steps are as follows: Step 1: Add 2.605 g of formamidine acetate and 50 mL of oleic acid to a 100 mL three-necked flask. o C for 1 hour. Then, fill with nitrogen and raise the temperature to 120 o C and hold for 30 minutes. Cool to 80 o C, and the FA-OA precursor solution was obtained.
[0021] Step 2: Add 0.688 g of lead iodide and 40 mL of 1-octadecene to a 250 mL three-necked flask at 90 °C. o C for 1 hour; under nitrogen environment, 8 mL oleic acid and 4 mL oleylamine were added in sequence, and the vacuum was continued for 30 minutes to obtain the synthesis reaction system of perovskite nanocrystals; 0.25 g benzyl phosphoric acid and 0.25 mL ethylamine were added, and the vacuum was continued for 10 minutes to obtain the perovskite nanocage reaction system. Then, nitrogen was introduced and the temperature was lowered to 80 o C, and then quickly inject 10 mL of FA-OA precursor solution. After reacting for 5 to 10 seconds, it is immediately cooled to room temperature in an ice bath to obtain a crude solution of FAPbI3 nanocages.
[0022] Step 3: Transfer the crude FAPbI3 nanocage solution to two centrifuge tubes, add 2 mL of toluene and 10 mL of methyl acetate to each tube, and centrifuge at 8000 rpm for 10 minutes. Collect the precipitate and redisperse it in 10 mL of n-hexane to obtain a FAPbI3 nanocage solution.
[0023] In this embodiment, the structural formula of benzyl phosphonic acid is:
[0024] See attached Figure 1 , which shows the transmission electron microscope image of the FAPbI3 perovskite nanocage prepared in this example, which has a size of about 12 nm and has obvious hollow structural characteristics.
[0025] See attached Figure 2 , is the fluorescence spectrum of the nanocage, showing that the emission peak is located at 778 nm and the half-peak width is 46 nm. Example 2
[0026] This embodiment provides a FAPbI3 perovskite nanocage material synthesized based on a hot injection method, and its preparation method and specific steps are as follows: Step 1: Add 2.605 g of formamidine acetate and 50 mL of oleic acid to a 100 mL three-necked flask. o C for 1 hour. Then, fill with nitrogen and raise the temperature to 120 o C and hold for 30 minutes. Cool to 80 o C, and the FA-OA precursor solution was obtained.
[0027] Step 2: Add 0.688 g of lead iodide and 40 mL of 1-octadecene to a 250 mL three-necked flask at 90 °C. o C for 1 hour. In a nitrogen environment, 4 mL of oleic acid and 4 mL of oleylamine were added in sequence, and the vacuum was continued for 30 minutes to obtain a perovskite nanocrystal synthesis reaction system. Then, 0.5 mL of butylamine and 3.5 g of dibenzyl phosphate were added and the vacuum was continued for 10 minutes to obtain a perovskite nanocage reaction system. Then, nitrogen was introduced and the temperature was lowered to 80 o C, and then quickly inject 10 mL of FA-OA precursor solution. After reacting for 5 to 10 seconds, it is immediately cooled to room temperature in an ice bath to obtain a crude solution of FAPbI3 nanocages.
[0028] Step 3: Transfer the crude FAPbI3 nanocage solution to two centrifuge tubes, add 2 mL of toluene and 10 mL of methyl acetate to each tube, and centrifuge at 8000 rpm for 10 minutes. Collect the precipitate and redisperse it in 10 mL of n-hexane to obtain a FAPbI3 nanocage solution.
[0029] In this embodiment, the structural formula of dibenzyl phosphate is:
[0030] See attached Figure 3 , which shows the transmission electron microscope image of the FAPbI3 perovskite nanocage prepared in this example, which has a size of about 19.8 nm and has obvious hollow structural characteristics.
[0031] See attached Figure 4 , is the fluorescence spectrum of the nanocage, showing that the emission peak is located at 789 nm and the half-peak width is 50 nm. Example 3
[0032] This embodiment provides a FAPbI3 perovskite nanocage material synthesized based on a hot injection method, and its preparation method and specific steps are as follows: Step 1: Add 2.605 g of formamidine acetate and 50 mL of oleic acid to a 100 mL three-necked flask. o C for 1 hour. Then, fill with nitrogen and raise the temperature to 120 o C and hold for 30 minutes. Cool to 80 o C, and the FA-OA precursor solution was obtained.
[0033] Step 2: Add 0.688 g of lead iodide and 40 mL of 1-octadecene to a 250 mL three-necked flask at 90 °C. o C for 1 hour. Under nitrogen environment, add 4 mL of oleylamine and continue to vacuum for 30 minutes to obtain the synthesis reaction system of perovskite nanocrystals. Then add 0.5 mL of butylamine and 3.5 g of dibenzyl phosphate and vacuum for 10 minutes to obtain the perovskite nanocage reaction system. Then, introduce nitrogen and lower the temperature to 80 o C, and then quickly inject 10 mL of FA-OA precursor solution. After reacting for 5 to 10 seconds, it is immediately cooled to room temperature in an ice bath to obtain a crude solution of FAPbI3 nanocages.
[0034] Step 3: Transfer the crude FAPbI3 nanocage solution to two centrifuge tubes, add 2 mL of toluene and 10 mL of methyl acetate to each tube, and centrifuge at 8000 rpm for 10 minutes. Collect the precipitate and redisperse it in 10 mL of n-hexane to obtain a FAPbI3 nanocage solution.
[0035] In this embodiment, the structural formula of dibenzyl phosphate is:
[0036] See attached Figure 5 , which shows the transmission electron microscopy image of the FAPbI3 perovskite nanocage prepared in this example, which has a size of about 24 nm and has an obvious hollow size of about 8.2 nm.
[0037] See attached Figure 6 , is the fluorescence spectrum of the nanocage, showing that the emission peak is located at 781 nm and the half-peak width is 46 nm. Example 4
[0038] This embodiment provides a FAPbI3 perovskite nanocage material synthesized based on a hot injection method, and its preparation method and specific steps are as follows: Step 1: Add 2.605 g of formamidine acetate and 50 mL of oleic acid to a 100 mL three-necked flask. o C for 1 hour. Then, fill with nitrogen and raise the temperature to 120 o C and hold for 30 minutes. Cool to 80 o C, and the FA-OA precursor solution was obtained.
[0039] Step 2: Add 0.688 g of lead iodide and 40 mL of 1-octadecene to a 250 mL three-necked flask at 90 °C. o C for 1 hour. Under nitrogen environment, add 4 mL of oleylamine and continue to vacuum for 30 minutes to obtain the synthesis reaction system of perovskite nanocrystals. Continue to add 1.75 g of dibenzyl phosphate potassium salt and vacuum for 10 minutes to obtain the perovskite nanocage reaction system. Then, introduce nitrogen and lower the temperature to 80 o C, and then quickly inject 10 mL of FA-OA precursor solution. After reacting for 5 to 10 seconds, it is immediately cooled to room temperature in an ice bath to obtain a crude solution of FAPbI3 nanocages.
[0040] Step 3: Transfer the crude FAPbI3 nanocage solution to two centrifuge tubes, add 2 mL of toluene and 10 mL of methyl acetate to each tube, and centrifuge at 8000 rpm for 10 minutes. Collect the precipitate and redisperse it in 10 mL of n-hexane to obtain a FAPbI3 nanocage solution.
[0041] In this embodiment, the structural formula of dibenzyl phosphate potassium salt is:
[0042] See attached Figure 7 , which shows the transmission electron microscopy image of the FAPbI3 perovskite nanocage prepared in this example, which has a size of about 28 nm and has an obvious hollow size of about 9.9 nm.
[0043] See attached Figure 8 , is the fluorescence spectrum of the nanocage, showing that the emission peak is at 782 nm and the half-peak width is 47 nm. Example 5
[0044] This embodiment provides a FAPbI3 perovskite nanocage material synthesized based on a ligand-assisted coprecipitation method, and its preparation method and specific steps are as follows: Step 1: Mix 250 μL of FABr solution (0.8 mol / L) dissolved in DMF, 250 μL of PbI2 solution (0.4 mol / L) dissolved in DMF, and 200 μL of oleic acid in a bottle to obtain a perovskite nanocrystal reaction system, then add 50 mg of dibenzyl phosphate and 25 μL of octylamine to obtain a perovskite nanocage reaction system, and use a vortex mixer for strong shaking to prepare a reaction precursor solution.
[0045] Step 2: Add the reaction system dropwise into a solution containing 8 mL of chloroform and stir vigorously for 35 seconds to obtain a crude solution of FAPbI3 nanocages.
[0046] Step 3: Transfer the crude FAPbI3 nanocage solution to two centrifuge tubes, add 2 mL of toluene and 10 mL of methyl acetate to each tube, and centrifuge at 8000 rpm for 10 minutes. Collect the precipitate and redisperse it in 10 mL of n-hexane to obtain a FAPbI3 nanocage solution.
[0047] In this embodiment, the structural formula of benzyl phosphonic acid is:
[0048] See attached Fig. 9 , which shows the transmission electron microscopy image of the FAPbI3 perovskite nanocage prepared in this example, which has a size of about 55 nm and has an obvious hollow size of about 20 nm.
Claims
1. A method for preparing a perovskite nanocage material, characterized in that: In the synthesis reaction system of perovskite nanocrystals, an auxiliary agent having vacancy formation and diffusion functions, or an organic metal salt compound auxiliary agent having both vacancy formation and diffusion functions is added to form a mixture to obtain a perovskite nanocage reaction system; and a perovskite nanocage material is obtained through a nucleation growth synthesis reaction; The structure of the perovskite is ABX3, where A is Cs + , CH(NH2)2 + or CH3NH3 + , B is Pb 2+ , Sn 2+ or Yb 2+ , X is I - , Cl - or Br - ; The auxiliary agent having the function of forming vacancies has the structural formula: , , , One or more of, wherein n is the number of carbon atoms, n=1-5; X is one of a mercapto group, a phosphino group, an ammonium group, a carboxyl group or a sulfonic acid group; The auxiliary agent with diffusion function includes a cation or anion metal salt, or an organic molecule, whose ion radius is smaller than that of the perovskite.
2. The method for preparing a perovskite nanocage material according to claim 1, characterized in that: The metal salt is a sodium salt, a magnesium salt or a potassium salt.
3. The method for preparing a perovskite nanocage material according to claim 1, characterized in that: The structure of the organic molecule is: ， Wherein, n is the number of carbon atoms, n=1-8; X is one of a mercapto group, a phosphino group, an ammonium group, a carboxyl group or a sulfonic acid group.
4. The method for preparing a perovskite nanocage material according to claim 1, characterized in that: The organic metal salt compound auxiliary agent having both vacancy formation and diffusion functions is selected from sodium benzenesulfonate, dibenzyl potassium phosphate, dibenzyl sodium dithiophosphate, sodium benzylphosphonate, sodium phenylacetate, and potassium phenylacetate.
5. The method for preparing a perovskite nanocage material according to claim 1, characterized in that: In the perovskite nanocage reaction system, the molar ratio of the auxiliary agent with vacancy formation function to the A-site cation of the perovskite structure is 0.2-5; the molar ratio of the auxiliary agent with diffusion function to the A-site cation of the perovskite structure is 0.2-10.
6. The method for preparing a perovskite nanocage material according to claim 1, characterized in that: The method of the nucleation growth synthesis reaction is a hot injection method, a reprecipitation method, a chemical vapor deposition method, a ball milling method, a probe ultrasound method or a microwave radiation method.
7. A perovskite nanocage material obtained by the preparation method of claim 1, having a cavity structure.
8. A perovskite nanocage material according to claim 7, characterized in that: The size of perovskite nanocages is 5 to 100 nm; the cavity size of perovskite nanocages is 1 to 80 nm.
9. The perovskite nanocage material according to claim 7, characterized in that: Its fluorescence emission peak is between 300 and 900 nm.