A ligand-assisted re-deposition method for preparing lead halide perovskite nanocrystal materials
By using ligand-assisted redeposition with ethyl acetate and zinc bromide, the problems of solvent waste and complex purification in traditional methods are solved, and lead halide perovskite nanocrystals with good luminescence properties are prepared, which are suitable for large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIANGTAN UNIV
- Filing Date
- 2024-12-16
- Publication Date
- 2026-06-16
AI Technical Summary
Traditional ligand-assisted redeposition methods for preparing lead halide perovskite nanocrystals suffer from solvent waste and complex purification steps, and it is difficult to control the size and luminescence properties of the nanocrystals.
Lead halide perovskite nanocrystals were prepared by ligand-assisted redeposition using ethyl acetate as the antisolvent and zinc bromide as the addition method, which simplified the purification steps and optimized the size and luminescence properties of the material.
Low-cost, simple, and rapid nanocrystal preparation was achieved, resulting in lead halide perovskite nanocrystals with excellent luminescence properties and tunable luminescence range, reducing solvent waste and improving material stability.
Smart Images
Figure CN122212232A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optoelectronic material preparation technology, specifically to a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials. Background Technology
[0002] Inorganic lead halide perovskite material CsPbX3 (where X = Cl, Br, I) has become a rapidly growing emerging semiconductor material due to its success in photovoltaic devices. It possesses the advantages of organic-inorganic perovskite materials, such as high light absorption coefficient, long carrier lifetime, and simple fabrication process, and maintains excellent stability even under humid and hot corrosion. Therefore, it has a very broad range of applications, including photocatalysis, photodetectors, and light-emitting diodes. Thus, it is considered a promising material for light-emitting and display applications.
[0003] With inorganic perovskite nanocrystals becoming one of the most researched topics globally in recent years, various methods have been devised to synthesize metal halide perovskites with controllable size, shape, and photoelectric properties. Different synthesis methods result in varying physicochemical properties of the metal halide perovskites. Currently, the main methods for synthesizing perovskite nanocrystals include: hot injection, ultrasonication, ligand-assisted redeposition, and solvothermal methods. Among these, ligand-assisted redeposition does not require high temperatures or inert environments, making it a simple method for large-scale perovskite production. However, traditional methods lead to significant solvent waste, especially requiring multiple purification steps to remove impurities. Furthermore, numerous secondary phase nucleations can occur. Summary of the Invention
[0004] The purpose of this invention is to provide a new method for synthesizing lead halide perovskite nanocrystals by simplifying the purification steps and optimizing the size, morphology, and luminescence properties of inorganic lead halide perovskite materials through changing the type of antisolvent and adding zinc bromide.
[0005] To achieve the above objectives, the present invention provides the following solution:
[0006] A ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials, characterized by the following steps:
[0007] (1) Weigh out the powder in the following quantities: 0.147 g lead bromide, 0.085 g cesium bromide, and 0.09 g zinc bromide.
[0008] (2) Put the raw material into a glass bottle containing solution A and stir magnetically for 0.5 h. Then add the mixed solution into the glass bottle and stir magnetically for 0.5 h until the solution is clear and transparent.
[0009] (3) At room temperature, the precursor solution is added to the antisolvent solution under vigorous stirring and stirred for 1 min to obtain a crude solution of lead halide perovskite nanocrystals. Then, the solution is centrifuged and purified to obtain the lead halide perovskite nanocrystal solution.
[0010] Specifically, the present invention provides a novel preparation method for lead halide perovskite nanocrystals. By changing the type of antisolvent and adding zinc bromide, a new method for preparing lead halide perovskite nanocrystals is proposed, simplifying the purification steps and optimizing the luminescence properties of inorganic lead halide perovskite materials. The preparation method of the present invention has the advantages of low cost, simple operation, and rapid preparation; the method of the present invention can prepare inorganic lead halide perovskite nanocrystal materials with adjustable luminescence range, good photoluminescence properties, and high stability.
[0011] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials: the mixed solution in step (2) is 400 μL oleic acid and 800 μL oleylamine, and solution A is 10 mL N,N-dimethylformamide.
[0012] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials is provided: the volume ratio of the precursor solution to the antisolvent in step (3) is 1:15.
[0013] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials: the antisolvent in step (3) is ethyl acetate.
[0014] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials: the centrifugation process in step (3) is to centrifuge at 5000 rpm for 5 min, discard the supernatant, and collect the precipitate as the crude product.
[0015] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystal materials: the purification process in step (3) involves dispersing the crude product in an organic solvent, centrifuging at 3200 rpm for 2 min, collecting the supernatant, and obtaining the lead halide perovskite nanocrystal solution.
[0016] Furthermore, a ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials is provided: the organic solvent is a toluene solution, and the volume ratio of the organic solvent to the ethyl acetate is 1:1.
[0017] A lead halide perovskite nanocrystal, characterized in that it is prepared by the above-described preparation method; the average particle size of the prepared lead halide perovskite nanocrystal is 11.7 nm.
[0018] Furthermore, a lead halide perovskite nanocrystal: the structural formula of the lead halide perovskite nanocrystal is CsPbBr3.
[0019] The principle of the preparation method of lead halide perovskite nanocrystals provided by this invention is as follows: Cesium bromide, lead bromide, and zinc bromide are dissolved in N,N-dimethylformamide, and then injected into the antisolvent ethyl acetate in the presence of oleylamine oleic acid. Due to the significant change in solubility, organic particles are deposited to form nanocrystals. The addition of zinc bromide, on the one hand, reduces the surface Br₂... - Vacancies improve luminescence performance. On the other hand, good size and morphology control can be achieved.
[0020] The present invention discloses the following technical effects:
[0021] (1) This invention is based on the traditional ligand-assisted redeposition method. By replacing the commonly used toluene antisolvent with ethyl acetate, the reaction kinetics are enhanced and the resulting perovskite nanocrystals are allowed to aggregate rapidly. Through a simple preparation process, lead halide perovskite materials with excellent luminescence properties and adjustable luminescence range are obtained, saving solvent waste in the purification process and providing an economical, simple, and reliable new method.
[0022] (2) The preparation method disclosed in this invention is simple and easy to operate. By adjusting the amount of oleylamine, a strong emission spectrum with blue and green light can be obtained. The luminescence quantum yield is high and the half-peak width is narrow. The method provided by this invention does not require a complicated preparation process, harsh reaction conditions and protection of an inert atmosphere. The whole process can be carried out at room temperature and in an atmospheric environment. The preparation method is simple and fast and suitable for large-scale production. Attached Figure Description
[0023] To more clearly illustrate the solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 The XRD patterns are of the lead halide perovskite nanocrystals prepared in Examples 4-5 of this invention.
[0025] Figure 2 The emission spectra of lead halide perovskite nanocrystals prepared in Examples 1-3 of this invention are shown below.
[0026] Figure 3 This is a transmission electron microscope image of the lead halide perovskite nanocrystals prepared in Example 4 of the present invention;
[0027] Figure 4 This is a grain size distribution diagram of the lead halide perovskite nanocrystals prepared in Example 4 of the present invention; Detailed Implementation
[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the invention, but rather as a more detailed description of certain aspects, features, and embodiments of the invention.
[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within a stated range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation and testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. The specification and embodiments of this invention are merely exemplary.
[0032] The terms “include,” “including,” “have,” and “contain” used in this article are all open-ended, meaning they include but are not limited to.
[0033] Example 1
[0034] (1) Weigh out 0.085 g of cesium bromide powder, 0.147 g of lead bromide powder, and 0 g of zinc bromide powder (the amounts of substance are 0.4 mM, 0.4 mM, and 0 mM, respectively), and pour the raw materials into a glass bottle. Then measure out 400 μL of oleic acid, 200 μL of oleylamine, and 10 mL of N,N-dimethylformamide. First, pour the N,N-dimethylformamide solution into the glass bottle and place it on a magnetic stirrer and stir at 1500 r / min for 0.5 h. Then, pour in 400 μL of oleic acid and 200 μL of oleylamine and stir at 1500 r / min for 0.5 h until the solution is clear and transparent to obtain the precursor solution.
[0035] (2) Under room temperature conditions, 15 mL of ethyl acetate was added to a graduated cylinder, and 1 mL of the above precursor solution was added to the ethyl acetate under vigorous stirring. After stirring for 1 min, a crude solution of lead halide perovskite nanocrystals was obtained.
[0036] (3) At room temperature, the crude liquid was directly placed in a centrifuge and centrifuged at 5000 rpm for 5 min. The supernatant was discarded and the precipitate was collected as the crude product. 15 mL of toluene was measured, and the crude product was dispersed in the toluene. The mixture was then centrifuged at 3200 rpm for 2 min. The supernatant was collected to obtain the lead halide perovskite nanocrystal solution.
[0037] Example 2
[0038] (1) Weigh 0.085 g of cesium bromide powder, 0.147 g of lead bromide powder, and 0 g of zinc bromide powder (the amounts of substance are 0.4 mM, 0.4 mM, and 0 mM, respectively), and pour the raw materials into a glass bottle. Then measure 400 μL of oleic acid, 600 μL of oleylamine, and 10 mL of N,N-dimethylformamide. First, pour the N,N-dimethylformamide solution into the glass bottle and place it on a magnetic stirrer and stir at 1500 r / min for 0.5 h. Then, pour in 400 μL of oleic acid and 600 μL of oleylamine and stir at 1500 r / min for 0.5 h until the solution is clear and transparent to obtain the precursor solution.
[0039] (2) Under room temperature conditions, 15 mL of ethyl acetate was added to a graduated cylinder, and 1 mL of the above precursor solution was added to the ethyl acetate under vigorous stirring. After stirring for 1 min, a crude solution of lead halide perovskite nanocrystals was obtained.
[0040] (3) At room temperature, the crude liquid was directly placed in a centrifuge and centrifuged at 5000 rpm for 5 min. The supernatant was discarded and the precipitate was collected as the crude product. 15 mL of toluene was measured, and the crude product was dispersed in the toluene. The mixture was then centrifuged at 3200 rpm for 2 min. The supernatant was collected to obtain the lead halide perovskite nanocrystal solution.
[0041] Example 3
[0042] (1) Weigh 0.085 g of cesium bromide powder, 0.147 g of lead bromide powder, and 0 g of zinc bromide powder (the amounts of substance are 0.4 mM, 0.4 mM, and 0 mM, respectively), and pour the raw materials into a glass bottle. Then measure 400 μL of oleic acid, 1000 μL of oleylamine, and 10 mL of N,N-dimethylformamide. First, pour the N,N-dimethylformamide solution into the glass bottle and place it on a magnetic stirrer and stir at 1500 r / min for 0.5 h. Then, pour in 400 μL of oleic acid and 1000 μL of oleylamine and stir at 1500 r / min for 0.5 h until the solution is clear and transparent to obtain the precursor solution.
[0043] (2) Under room temperature conditions, 15 mL of ethyl acetate was added to a graduated cylinder, and 1 mL of the above precursor solution was added to the ethyl acetate under vigorous stirring. After stirring for 1 min, a crude solution of lead halide perovskite nanocrystals was obtained.
[0044] (3) At room temperature, the crude liquid was directly placed in a centrifuge and centrifuged at 5000 rpm for 5 min. The supernatant was discarded and the precipitate was collected as the crude product. 15 mL of toluene was measured, and the crude product was dispersed in the toluene. The mixture was then centrifuged at 3200 rpm for 2 min. The supernatant was collected to obtain the lead halide perovskite nanocrystal solution.
[0045] Example 4
[0046] (1) Weigh out 0.085 g of cesium bromide powder, 0.147 g of lead bromide powder, and 0.09 g of zinc bromide powder (the amounts of substance are 0.4 mM, 0.4 mM, and 0.4 mM, respectively), and pour the raw materials into a glass bottle. Then measure out 400 μL of oleic acid, 800 μL of oleylamine, and 10 mL of N,N-dimethylformamide. First, pour the N,N-dimethylformamide solution into the glass bottle and place it on a magnetic stirrer and stir at 1500 r / min for 0.5 h. Then, pour in 400 μL of oleic acid and 800 μL of oleylamine and stir at 1500 r / min for 0.5 h until the solution is clear and transparent to obtain the precursor solution.
[0047] (2) Under room temperature conditions, 15 mL of ethyl acetate was added to a graduated cylinder, and 1 mL of the above precursor solution was added to the ethyl acetate under vigorous stirring. After stirring for 1 min, a crude solution of lead halide perovskite nanocrystals was obtained.
[0048] (3) At room temperature, the crude liquid was directly placed in a centrifuge and centrifuged at 5000 rpm for 5 min. The supernatant was discarded and the precipitate was collected as the crude product. 15 mL of toluene was measured, and the crude product was dispersed in the toluene. The mixture was then centrifuged at 3200 rpm for 2 min. The supernatant was collected to obtain the lead halide perovskite nanocrystal solution.
[0049] Example 5
[0050] (1) Weigh out 0.085 g of cesium bromide powder, 0.147 g of lead bromide powder, and 0.09 g of zinc bromide powder (the amounts of substance are 0.4 mM, 0.4 mM, and 0.4 mM, respectively), and pour the raw materials into a glass bottle. Then measure out 400 μL of oleic acid, 800 μL of oleylamine, and 10 mL of N,N-dimethylformamide. First, pour the N,N-dimethylformamide solution into the glass bottle and place it on a magnetic stirrer and stir at 1500 r / min for 0.5 h. Then, pour in 400 μL of oleic acid and 800 μL of oleylamine and stir at 1500 r / min for 0.5 h until the solution is clear and transparent to obtain the precursor solution.
[0051] (2) Under room temperature conditions, 15 mL of toluene was added to a graduated cylinder, and 1 mL of the above precursor solution was added to the toluene under vigorous stirring. After stirring for 1 min, a crude liquid of lead halide perovskite nanocrystals was obtained.
[0052] (3) At room temperature, the crude liquid was directly placed in a centrifuge and centrifuged at 5000 rpm for 5 min. The supernatant was discarded and the precipitate was collected as the crude product. 15 mL of toluene was measured, and the crude product was dispersed in the toluene. The mixture was then centrifuged at 3200 rpm for 2 min. The supernatant was collected to obtain the lead halide perovskite nanocrystal solution.
[0053] Performance characterization results
[0054] The lead halide perovskite nanocrystals prepared in Examples 4-5 above were characterized by X-ray diffraction, and the results are as follows: Figure 1 As shown. From Figure 1 As can be seen, the peak shapes of both prepared samples are consistent with those of the standard PDF card (PDF#18-0364), indicating that changing the antisolvent and adding zinc bromide do not affect the preparation of lead halide perovskite nanocrystals. The emission spectra of Examples 1-3 were measured using a Hitachi F-7000 fluorescence spectrophotometer. The emission spectrum curves of the perovskite nanocrystal solutions prepared in Examples 1-3 are shown below. Figure 2As shown, the emission spectrum gradually blue-shifts with increasing oleylamine content. This indicates that increasing the amount of oleylamine reduces the size of the perovskite nanocrystals, and oleylamine can effectively control the grain size of the nanocrystals. The lead halide perovskite nanocrystals prepared in Example 4 were characterized by transmission electron microscopy, and the results are as follows... Figure 3 As shown. Figure 4 The grain size distribution diagram is shown for the sample obtained in Example 4 above.
[0055] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the design of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A ligand-assisted redeposition method for preparing lead halide perovskite nanocrystals by changing the type of antisolvent and adding zinc bromide, characterized in that, Includes the following steps: (1) Weigh the raw materials: Weigh out the powders in the following order: 0.147 g lead bromide, 0.085 g cesium bromide, and 0.09 g zinc bromide; (2) Preparation of precursor solution: Put the raw material into a glass bottle containing solution A and stir magnetically for 0.5 h. Then add the mixed solution into the glass bottle and stir magnetically for 0.5 h until the solution is clear and transparent. (3) Preparation of lead halide perovskite nanocrystals: At room temperature, the precursor solution is added to the antisolvent solution under vigorous stirring and stirred for 1 min to obtain crude lead halide perovskite nanocrystal solution. Then, the solution is obtained by centrifugation and purification.
2. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The three-dimensional structure of the lead halide perovskite described in step (3) is a cubic structure with the structural formula CsPbBr3.
3. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The mixed solution in step (2) consists of 400 μL of oleic acid and 800 μL of oleylamine, and solution A consists of 10 mL of N,N-dimethylformamide.
4. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The volume ratio of the precursor solution to the antisolvent in step (3) is 1:
15.
5. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The antisolvent mentioned in step (3) is ethyl acetate.
6. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The centrifugation process described in step (3) involves centrifuging at 5000 rpm for 5 min, discarding the supernatant, and collecting the precipitate as the crude product.
7. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 6, characterized in that, The purification process in step (3) involves dispersing the crude product in an organic solvent, centrifuging at 3200 rpm for 2 min, collecting the supernatant, and obtaining the lead halide perovskite nanocrystal solution.
8. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 7, characterized in that, The organic solvent is a toluene solution, and the volume ratio of the organic solvent to the ethyl acetate of claim 4 is 1:
1.
9. The ligand-assisted redeposition method for preparing lead halide perovskite nanocrystalline materials according to claim 1, characterized in that, The average particle size of the lead halide perovskite nanocrystals described in step (3) is 11.7 nm.