Preparation method of organic-inorganic hybrid perovskite quantum dots
By controlling the diffusion process to slow down the transport rate of the reaction precursor, high-quality organic-inorganic hybrid perovskite nanocrystals were prepared, solving the synthesis problem caused by rapid kinetics and enabling efficient mass production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUZHOU UNIV
- Filing Date
- 2024-01-24
- Publication Date
- 2026-07-24
AI Technical Summary
Existing technologies make it difficult to synthesize high-quality organic-inorganic hybrid perovskite nanocrystals, especially due to the rapid kinetics during the reaction process, which increases the difficulty of synthesis.
By employing a diffusion-controlled approach, the transport rate of the reaction precursor is slowed down by using a metal cation compound source with low solubility in the reaction system, and an excess of metal cation compound is used as a reserve source to continuously replenish the reaction system and maintain the size focusing state.
FAPbX3 and MAPbX3 nanocrystals with high PLQY and high size monodispersity were successfully prepared, extending the reaction window and enabling mass production. The reaction system maintained size focus for a longer period of time.
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Figure CN118047680B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of functional materials preparation technology, specifically to a method for synthesizing organic-inorganic hybrid perovskite quantum dots. Background Technology
[0002] Colloidal lead halide perovskite nanocrystals, as a new generation of nano-semiconductor materials, possess a series of excellent optoelectronic properties and show great application potential in optoelectronic applications such as light-emitting diodes, scintillators, lasers, and solar cells. However, due to the ionic properties of perovskite materials, they exhibit extremely fast reaction kinetics, and currently reported synthesis methods all require the reaction to terminate within seconds (see: Protesescu, L. et al. Dismantling the “redwall” of colloidal perovskites: Highly luminescent formamidinium and formamidinium–cesium lead iodide nanocrystals. ACS Nano 11, 3119-3134(2017).; Imran, M. et al. Benzoyl halides as alternative precursors for the colloidal synthesis of lead-based halide perovskite nanocrystals. J. Am.Chem. Soc. 140, 2656-2664 (2018).), which poses a significant challenge to the synthesis of high-quality perovskite nanocrystals. Kovalenko's team achieved rate-limited growth of CsPbBr3 perovskite nanocrystals by introducing a strongly binding ligand (TOPO) to suppress the reactivity of the lead source (see: Akkerman, QA et al. Controlling the nucleation and growth kinetics of lead halide perovskite quantum dots). Science 377, 1406-1412 (2022)., extending the reaction time to approximately 30 minutes. However, the effectiveness of this method is limited in the synthesis of organic-inorganic hybrid perovskite nanocrystals.
[0003] Compared to all-inorganic perovskites, organic-inorganic hybrid perovskites possess a wider range of properties, and their bulk materials are currently the mainstream materials for high-performance optoelectronic applications. However, due to the strong ionic properties of organic-inorganic hybrid perovskites, their synthesis is more challenging. Currently, there is a lack of effective methods to synthesize high-quality organic-inorganic hybrid perovskite nanocrystals. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing high-quality organic-inorganic hybrid perovskite quantum dots through diffusion control during the synthesis process.
[0005] The technical solution to achieve the objective of this invention is: to provide a method for preparing organic-inorganic hybrid perovskite quantum dots, comprising the following steps: 1) A compound containing unit A and an organic acid are added to a reaction solvent and reacted fully at a temperature of 40–80°C to obtain precursor solution I; the unit A includes formamidinium (FA), methylamine (MA), and phenylethylamine (PEA); the molar concentration of unit A in the organic acid is 0.2–0.5 M; 2) Add the compound containing element X and the organic amine to the reaction solvent and react fully at a temperature of 80-120℃ to obtain precursor solution II; the element X includes I, Br, Cl, SCN, CN; the molar concentration of element X in the organic amine is 2-8M; 3) Add the compound containing metal element B to the precursor solution I prepared in step 1) and mix. The solubility of the compound containing metal element B in the reaction system is less than 0.05 mol / L. The molar ratio of unit A to metal element B is 1 to 5:1. Inject the precursor solution II prepared in step 2) at a temperature of 60 to 120°C. After the reaction, obtain the mother liquor. The molar ratio of element X to metal element B is 1 to 5:1. The metal element B includes lead, tin, manganese, indium, and bismuth. 4) The mother liquor was purified to obtain an organic-inorganic hybrid perovskite quantum dot solution.
[0006] The technical solution provided by this invention includes the following: Step 1) The organic acids include oleic acid, alkylphosphonic acid, and alkylbenzene sulfonic acid. Step 2) The organic amines include oleylamine and alkylamine. Step 3) The compounds containing metal element B include lead thiocyanate, lead oleate, lead formate, lead chloride, lead nitrate, lead carbonate, lead sulfide, stannous thiocyanate, stannous pyrophosphate, stannous oxalate, stannous sulfide, manganese acetate, indium chloride, indium bromide, and bismuth acetate. The reaction solvents in steps 1) and 2) are non-coordinate solvents for perovskite components A, B, and X.
[0007] This invention solves the synthesis difficulties of organic-inorganic hybrid perovskite nanocrystals by diffusion control. The principle is as follows: a metal cation compound source with low solubility is selected in the reaction system to slow down the transfer of precursors in the reaction system and prevent the precursors from being converted into monomers too quickly. At the same time, as the reaction proceeds, the excess metal cation compound in the system acts as a reserve source and is continuously released and replenished, so that the reaction system is always in the size focusing stage.
[0008] Compared with the prior art, the advantages of adopting the technical solution provided by the present invention are as follows: 1. A diffusion-controlled synthesis method was used in the perovskite organic-inorganic hybrid nanocrystal system to successfully prepare FAPbI3 perovskite nanocrystals with high PLQY and high size monodispersity. The synthesis method is universal and was successfully used to prepare FAPbX3 (X=Br, Cl;) and MAPbX3 (X=I, Br, Cl;) nanocrystals.
[0009] 2. The synthesis method provided by this invention significantly extends the reaction window, and the reaction system remains in a size-focused state. The preparation method achieves a reaction window of nearly 30 minutes in the FAPbI3 perovskite nanocrystal system, and the reaction system remains in a size-focused state even after 80 minutes of reaction. Due to the slower reaction kinetics and low-cost ligand-solvent reaction system, mass production can be achieved. Attached Figure Description
[0010] Figure 1 This is a comparison curve of the fluorescence peak position of the quantum dot mother liquor prepared by the traditional binary and ternary hot injection synthesis method and the diffusion-controlled synthesis method of the present invention as a function of reaction time in Example 1 of the present invention.
[0011] Figure 2 These are electron micrographs of the reaction solutions at different reaction times in Example 2 of this invention, showing the diffusion-controlled synthesis of FAPbI3 perovskite nanocrystals.
[0012] Figure 3 This is the absorption fluorescence spectrum of FAPbI3 perovskite nanocrystals synthesized using diffusion control in Example 2 of this invention, after 80 minutes of reaction. At this point, the full width at half maximum (FWHM) of the fluorescence is 39.4 nm.
[0013] Figure 4 The XRD patterns are those of FAPbI3 nanocrystals synthesized using the traditional ternary hot-injection synthesis method and the diffusion control method of Example 2 of this invention.
[0014] Figure 5 These are fluorescence absorption patterns, XRD patterns, and electron micrographs of the organic-inorganic hybrid perovskite nanocrystals provided in Examples 2, 3, and 4 of this invention.
[0015] Figure 6 These are fluorescence absorption patterns, XRD patterns, and electron micrographs of the organic-inorganic hybrid perovskite nanocrystals provided in Examples 5, 6, and 7 of this invention.
[0016] Figure 7 These are the original PLQY data diagrams of organic-inorganic hybrid perovskite nanocrystals provided in various embodiments of the present invention.
[0017] Figure 8 These are characterization diagrams related to the batch synthesis of FAPbI3 perovskite nanocrystals obtained by the diffusion-controlled synthesis method provided in this embodiment of the invention. Detailed Implementation
[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0019] Example 1: In this example, FAPbI3 perovskite nanocrystals were prepared using the traditional binary hot injection method, the ternary hot injection method, and the diffusion-controlled synthesis method provided by the present invention.
[0020] 1. Preparation of FAPbI3 perovskite nanocrystals using the traditional binary hot-injection method: 1) Preparation of FA precursors Add 0.52g of formamidine acetate to 10mL of oleic acid, heat at 50°C, stir, and vacuum until the reaction is complete.
[0021] 2) Add 0.344g of lead iodide to 20mL of octadecene, heat and stir at 90℃ under vacuum, then inject 4mL of oleic acid and 2mL of oleylamine, continue heating and stirring under vacuum until the reaction is complete. Slowly cool to 80℃, then quickly inject 5mL of FA precursor solution.
[0022] 3) Real-time testing is performed using in-situ fluorescence testing equipment.
[0023] 2. Preparation of FAPbI3 perovskite nanocrystals using the traditional ternary hot-injection method: 1) Preparation of iodine precursor sources Add 1.5g of ammonium iodide to 5mL of oleylamine, heat at 90℃, stir and evacuate until the reaction is complete.
[0024] 2) Add 0.39g of formamidine acetate and 10mL of oleic acid to 40mL of octadecene, heat and stir at 50℃ under vacuum, slowly raise the temperature to 80℃, and quickly inject 1.45mL of iodine precursor solution.
[0025] 3) Real-time testing is performed using in-situ fluorescence testing equipment.
[0026] 3. Preparation of FAPbI3 perovskite nanocrystals using a diffusion-controlled synthesis method: 1) Preparation of FA precursor solution: Add 0.39g of formamidine acetate and 16mL of oleic acid to 40mL of octadecene, heat and stir at 50℃ and vacuum until the reaction is complete.
[0027] 2) Add 11.2 ml of FA precursor solution and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of I precursor solution (the content of iodine in oleylamine is 6.2 M, and the molar ratio of iodine to lead is 3:1).
[0028] 3) Real-time testing is performed using in-situ fluorescence testing equipment.
[0029] See appendix Figure 1 The graph shows a comparison of the fluorescence peak position of the quantum dot mother liquor obtained by the traditional binary and ternary thermal injection synthesis methods and the diffusion-controlled synthesis method provided in this embodiment, as a function of reaction time.
[0030] Example 2: Preparation of FAPbI3 perovskite nanocrystals.
[0031] 1) Preparation of FA precursor solution: Add 0.39g of formamidine acetate and 16mL of oleic acid to 40mL of octadecene, heat and stir at 50℃ and vacuum until the reaction is complete.
[0032] 2) Add 11.2 ml of FA precursor solution and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of I precursor solution (the content of iodine in oleylamine is 6.2 M, and the molar ratio of iodine to lead is 3:1).
[0033] 3) The reaction was stopped in an ice-water bath at different times (30s; 3min; 8min; 15min; 45min; and 80min respectively).
[0034] 4) Transfer the reaction stock solution to a centrifuge tube, add methyl acetate at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the bottom precipitate, and redisperse with 5 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the bottom precipitate, disperse with 5 ml of toluene, and store in a refrigerator.
[0035] See appendix Figure 2 The images shown are electron micrographs of the reaction solutions taken out at different reaction times in step 3) of this embodiment: a) 30s; b) 3min; c) 8min; d) 15min; e) 45min; f) 80min; which characterize the morphology of the nanocrystals at different reaction times.
[0036] Figure 3 This is the absorption fluorescence spectrum of FAPbI3 perovskite nanocrystals synthesized using diffusion control in this embodiment, after 80 minutes of reaction. At this point, the full width at half maximum (FWHM) of the fluorescence is 39.4 nm.
[0037] See appendix Figure 4 The image shows the XRD pattern of FAPbI3 nanocrystals synthesized using the traditional ternary hot-injection synthesis method and the diffusion control method of this embodiment (after 16 minutes of reaction).
[0038] See appendix Figure 5 Among them, a1, a2 and a3 are the fluorescence absorption PLQY pattern, XRD pattern and electron microscope image of the organic-inorganic hybrid perovskite nanocrystals (FAPbI3) prepared in this embodiment (after reacting for 16 minutes).
[0039] See appendix Figure 7 Figure a is a raw PLQY data diagram of FAPbI3 (reacted for 16 minutes) organic-inorganic hybrid perovskite nanocrystals provided in this embodiment.
[0040] Example 3: Preparation of FAPbBr3 perovskite nanocrystals.
[0041] 1) Add 11.2 ml of FA precursor solution (prepared according to step 1 of Example 2) and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of Br precursor solution (bromine content in oleylamine is 6.2 M, and the molar ratio of bromine to lead is 3:1).
[0042] 2) Stop the reaction in an ice-water bath after 12 minutes.
[0043] 3) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene before storing in a refrigerator.
[0044] See appendix Figure 5 Figures b1, b2, and b3 are the fluorescence absorption spectrum, XRD pattern, and electron microscope image of the FAPbBr3 organic-inorganic hybrid perovskite nanocrystals prepared in this embodiment, respectively.
[0045] See appendix Figure 7Figure b is the PLQY raw data diagram of FAPbBr3 organic-inorganic hybrid perovskite nanocrystals provided in this embodiment.
[0046] Example 4: Preparation of FAPbCl3 perovskite nanocrystals.
[0047] 1) Add 11.2 ml of FA precursor solution (prepared according to step 1 of Example 2) and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of Cl precursor solution (the content of chlorine in oleylamine is 6.2 M, and the molar ratio of chlorine to lead is 3:1).
[0048] 2) Stop the reaction in an ice-water bath after 8 minutes.
[0049] 3) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene before storing in a refrigerator.
[0050] See appendix Figure 5 In the figure, c1, c2 and c3 are the fluorescence absorption pattern, XRD pattern and electron microscope image of the FAPbCl3 organic-inorganic hybrid perovskite nanocrystals prepared in this embodiment, respectively.
[0051] See appendix Figure 7 Figure c is the raw PLQY data of FAPbBr3 organic-inorganic hybrid perovskite nanocrystals provided in this embodiment.
[0052] Example 5: Preparation of MAPbI3 perovskite nanocrystals.
[0053] 1) Preparation of MA precursor solution: Add 0.34g methylamine acetate and 16mL oleic acid to 40mL octadecene, heat and stir at 50℃ and vacuum until the reaction is complete.
[0054] 2) Add 11.2 ml of MA precursor solution and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of I precursor solution (the content of iodine in oleylamine is 6.2 M, and the molar ratio of iodine to lead is 3:1).
[0055] 3) Stop the reaction in an ice-water bath after 16 minutes.
[0056] 4) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene before storing in a refrigerator.
[0057] See appendix Figure 6 Among them, a1, a2 and a3 are the fluorescence absorption PLQY pattern, XRD pattern and electron microscope image of the MAPbI3 organic-inorganic hybrid perovskite nanocrystals prepared in this embodiment.
[0058] See appendix Figure 7 In this embodiment, d is the raw PLQY data of MAPbI3 organic-inorganic hybrid perovskite nanocrystals.
[0059] Example 6: Preparation of MAPbBr3 perovskite nanocrystals.
[0060] 1) Add 11.2 ml of MA precursor solution (prepared according to step 1 of Example 5) and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of Br precursor solution (the content of bromine in oleylamine is 6.2 M, and the molar ratio of bromine to lead is 3:1).
[0061] 2) Stop the reaction in an ice-water bath after 12 minutes.
[0062] 3) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene before storing in a refrigerator.
[0063] See appendix Figure 6 Among them, b1, b2 and b3 are the fluorescence absorption PLQY pattern, XRD pattern and electron microscope image of the MAPbBr3 organic-inorganic hybrid perovskite nanocrystals prepared in this embodiment, respectively.
[0064] See appendix Figure 7 Figure e is the PLQY raw data diagram of MAPbBr3 organic-inorganic hybrid perovskite nanocrystals provided in this embodiment.
[0065] Example 7: Preparation of MAPbCl3 perovskite nanocrystals.
[0066] 1) Add 11.2 ml of MA precursor solution (prepared according to step 1 of Example 5) and 0.1938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 0.58 ml of Cl precursor solution (the content of chlorine in oleylamine is 6.2 M, and the molar ratio of chlorine to lead is 3:1).
[0067] 2) Stop the reaction in an ice-water bath after 8 minutes.
[0068] 3) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 2 ml of toluene before storing in a refrigerator.
[0069] See appendix Figure 6 In the figure, c1, c2 and c3 are the fluorescence absorption PLQY pattern, XRD pattern and electron microscope image of the MAPbCl3 organic-inorganic hybrid perovskite nanocrystals prepared in this embodiment, respectively.
[0070] See appendix Figure 7 Figure f is the PLQY raw data diagram of MAPbCl3 organic-inorganic hybrid perovskite nanocrystals provided in this embodiment.
[0071] Example 8: Mass production of FAPbI3 perovskite nanocrystals.
[0072] 1) Add 112 ml of FA precursor solution (prepared according to step 1 of Example 2) and 1.938 g of lead thiocyanate to the reaction vessel, stir and heat to 80°C. After the temperature stabilizes, inject 5.8 ml of I precursor solution (the content of iodine in oleylamine is 6.2 M, and the molar ratio of iodine to lead is 3:1).
[0073] 2) Stop the reaction in an ice-water bath after 16 minutes.
[0074] 3) Transfer the reaction stock solution to two centrifuge tubes, add methyl acetate to each at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 10 ml of toluene. Then, centrifuge the solution at 1,000 rpm for 3 min, retain the supernatant. Add methyl acetate to each again at a 1:1 ratio, centrifuge at 10,000 rpm for 5 min, retain the precipitate at the bottom, and redisperse each with 10 ml of toluene before storing in a refrigerator.
[0075] See appendix Figure 8Figures 1 and 2 represent a series of characterizations of the batch synthesis of FAPbI3 perovskite nanocrystals obtained by the diffusion-controlled synthesis method in this embodiment. Figure a shows the absorption fluorescence pattern; Figure b shows the raw PLQY data; Figures c and d show the electron micrographs of the batch synthesized nanocrystals.
Claims
1. A method for preparing organic-inorganic hybrid perovskite quantum dots, characterized in that... Includes the following steps: 1) A compound containing unit A and an organic acid are added to a reaction solvent and reacted fully at a temperature of 40–80°C to obtain precursor solution I; the unit A is selected from formamidin, methylamine, and phenylethylamine; the molar concentration of unit A in the organic acid is 0.2–0.5 M; 2) The compound containing element X and the organic amine are added to the reaction solvent and reacted fully at a temperature of 80-120℃ to obtain precursor solution II; the element X is selected from I, Br, Cl, SCN, CN; the molar concentration of element X in the organic amine is 2-8M; 3) Add the compound containing metal element B to the precursor solution I prepared in step 1) and mix. The solubility of the compound containing metal element B in the reaction system is less than 0.05 mol / L, and the molar ratio of unit A to metal element B is 1 to 5:
1. Add the precursor solution II prepared in step 2) at a temperature of 60 to 120°C. After the reaction, obtain the mother liquor. The molar ratio of element X to metal element B is 1 to 5:
1. The metal element B is selected from lead, tin, manganese, indium, and bismuth. 4) The mother liquor was purified to obtain an organic-inorganic hybrid perovskite quantum dot solution.
2. The method for preparing organic-inorganic hybrid perovskite quantum dots according to claim 1, characterized in that: The organic acid mentioned in step 1) is selected from oleic acid, alkylphosphonic acid, and alkylbenzene sulfonic acid.
3. The method for preparing organic-inorganic hybrid perovskite quantum dots according to claim 1, characterized in that: The organic amine mentioned in step 2) is an alkylamine.
4. The method for preparing organic-inorganic hybrid perovskite quantum dots according to claim 1, characterized in that: The compound containing metal element B mentioned in step 3) is one or more of lead thiocyanate, lead oleate, lead formate, lead chloride, lead nitrate, lead carbonate, lead sulfide, stannous thiocyanate, stannous pyrophosphate, stannous oxalate, stannous sulfide, manganese acetate, indium chloride, indium bromide, and bismuth acetate.
5. The method for preparing organic-inorganic hybrid perovskite quantum dots according to claim 1, characterized in that: The reaction solvents described in steps 1) and 2) are noncoordinating solvents for perovskite components A, B, and X.