Preparation method of two-dimensional perovskite quantum dot array
By preparing a two-dimensional perovskite quantum dot array structure, the disorder and stability of traditional perovskite quantum dots in charge transfer and mechanical properties are solved, and high-efficiency charge transfer and stability are achieved, suitable for complex environments and High brightness display application.
Patent Information
- Application Number
- CN202411220044.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-01-17
AI Technical Summary
Traditional monodispersed perovskite quantum dots have disorder and energy losses in charge transport and mechanical properties, and are unstable to external factors, making it difficult to adapt to complex environments and efficient luminescence requirements.
Using the preparation method of two-dimensional perovskite quantum dot array structure, the preparation of precursor liquid, synthesis of perovskite quantum dot solution, purification and light-induced self-assembly, form an orderly two-dimensional perovskite quantum dot array to improve charge transfer efficiency and structural stability.
It achieves more efficient charge transfer, reduces energy loss, enhances structural stability, improves luminescent quantum yield and mechanical properties, and is suitable for complex environments and high-brightness display applications.
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Figure CN119320635A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the fields of nano functional materials and display lighting, and in particular to a method for preparing a two-dimensional perovskite quantum dot array. Background Art
[0002] Halide perovskite nanocrystals exhibit a series of extremely outstanding characteristics, such as excellent fluorescence quantum yield, which indicates that it can produce brighter and more efficient fluorescence, and the narrow half-peak width, a remarkable characteristic, makes the color purity of the light it emits reach an extremely high level, and the color recognition is greatly improved. The remarkable feature of low nucleation temperature greatly reduces the difficulty and cost of preparation, creating feasible conditions for large-scale production. In addition, the fluorescence emission peak with adjustable composition and size gives it great flexibility and customizability, and can accurately customize specific wavelengths of light according to different actual needs. Because of this, halide perovskite nanocrystals have been widely used in many fields such as solar cells, light-emitting diodes, and photodetectors.
[0003] Compared with traditional monodisperse perovskite quantum dots, the two-dimensional perovskite quantum dot array structure provides a more ordered and efficient path for charge transfer, reducing energy loss during the transmission process. At the same time, the ordered arrangement can enhance the stability of the structure to a certain extent and reduce the impact of external factors on optical properties: its unique two-dimensional array structure helps to improve the quantum yield of luminescence; the array structure enables the material to have better mechanical properties and adapt to more application scenarios. Summary of the invention
[0004] The present invention provides a method for preparing a two-dimensional perovskite quantum dot array, and the specific steps are as follows:
[0005] S1: prepare precursor solution A;
[0006] S2: Synthesize perovskite quantum dot B solution;
[0007] S3: purifying the perovskite quantum dot solution B once to obtain a purified perovskite quantum dot solution C;
[0008] S4: preparing a two-dimensional perovskite quantum dot array D solution;
[0009] S5: Centrifugally purify the perovskite quantum dot array D solution once to obtain a clean perovskite quantum dot two-dimensional array solution.
[0010] Furthermore, step S1 is specifically as follows:
[0011] The cesium halide, lead salt, monovalent alkali metal salt, organic cationic ligand, organic anionic ligand and organic solvent are fully mixed and continuously stirred for a predetermined time under specific temperature conditions, thereby successfully obtaining a clear and transparent precursor solution A.
[0012] Furthermore, step S2
[0013] A certain amount of non-polar solvent is taken and stirred, the precursor solution A is heated to a certain temperature, and while the non-polar solvent is stirred, the precursor solution A is added to the non-polar solvent to obtain a perovskite quantum dot B solution.
[0014] Furthermore, step S3 is specifically as follows:
[0015] A predetermined amount of anti-solvent is added to the perovskite quantum dot B obtained in S2 and centrifuged. Subsequently, the obtained precipitate is added to the solvent and dispersed again to obtain a purified perovskite quantum dot C solution.
[0016] Furthermore, step S4 is specifically as follows:
[0017] Under certain temperature and humidity, a light source of a certain power is placed at a certain distance from the perovskite quantum dot C solution and irradiated for a certain period of time, so that the perovskite quantum dot C solution is self-assembled into a two-dimensional perovskite quantum dot array D solution through light induction.
[0018] Furthermore, step S5 is specifically as follows:
[0019] A predetermined amount of anti-solvent is added to the two-dimensional perovskite quantum dot array D solution obtained in S4 and centrifuged. Subsequently, the obtained precipitate is added to the solvent and dispersed again to obtain a purified two-dimensional perovskite quantum dot array E solution.
[0020] Further, in step S1, the cesium halide is one or more of cesium fluoride, cesium chloride, cesium bromide, and cesium iodide; the lead salt is one or more of lead acetate, lead fluoride, lead cation, lead stearate, lead carbonate, lead nitrate, lead bromide, lead iodide, lead molybdate, lead chloride, lead arsenate, lead tungstate, lead vanadate, lead titanate, lead silicate, lead borate, lead laurate, lead myristate, lead palmitate, lead stearate, lead maleate, lead fumarate, lead tartrate, and lead citrate; the monovalent alkali metal salt is rubidium fluoride, rubidium chloride, rubidium bromide, rubidium iodide, fluoride, One or more of potassium, potassium chloride, potassium bromide, potassium iodide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, lithium fluoride, lithium chloride, lithium bromide, lithium iodide; organic cationic ligands may be, but are not limited to, one or more of oleylamine, dodecylamine, hexadecylamine, trioctylamine, tributylamine, and octylamine; organic anionic ligands are one or more of oleic acid, stearic acid, oxalic acid, mercaptopropionic acid, dodecanethiol, thioglycolic acid, undecylenic acid, octanoic acid, and trioctylphosphine oxide; organic solvents are one or a combination of dimethyl sulfoxide and dimethylformamide. The specific temperature is 30-240°C; the stirring time is 25-240min; the stirring speed is 300rpm-800rpm. The concentration of precursor solution A is 0.0081-0.6753g / mL.
[0021] Furthermore, in step S2, the non-polar solvent is one or more of toluene, chlorobenzene, benzene, m-xylene, carbon tetrachloride, petroleum ether, and n-hexane; the heating temperature of the precursor solution A is 30-75°C, and the stirring speed of the non-polar solvent is 200-900rpm.
[0022] Furthermore, in step S3, the volume ratio of the anti-solvent to the solvent is 0.3-2.2:1, the solvent is one of toluene, n-hexane, cyclohexane, benzene, and octane, the anti-solvent is one or more of methyl acetate and ethyl acetate, and the concentration of the perovskite quantum dot C solution is 5.5-84.5 mg / mL; the speed during centrifugation is 1500-7000 rpm, and the centrifugation time is 2-15 min.
[0023] Furthermore, in step S4, the temperature is 30-40°C; the humidity is 50%-65%; the light source is 5-60cm away from the perovskite quantum dot C solution; the power of the light source is 1-220W; the irradiation time is 20min-12h; the light source is ultraviolet lamp, sunlight, laser, infrared light, monochromatic light.
[0024] Furthermore, in step S5, the volume ratio of the antisolvent to the solvent is 0.5-1.5:1, the solvent is one of toluene, n-hexane, cyclohexane, benzene, and octane, the antisolvent is one or more of methyl acetate and ethyl acetate, and the concentration of the perovskite two-dimensional array is 5.5-84.5 mg / mL; the rotation speed during centrifugation is 2000-8000 rpm, and the centrifugation time is 2-15 min.
[0025] Compared with traditional monodisperse perovskite quantum dots, the two-dimensional perovskite quantum dot array structure shows many remarkable advantages.
[0026] 1. In terms of charge transfer, it builds a more orderly and efficient path for the migration of charges. Traditional transmission methods are often disordered, resulting in a large amount of energy loss during the transmission process, and this unique array structure can greatly reduce this drawback. Through orderly arrangement, charges can move quickly and stably as if on a carefully laid track, minimizing energy loss. For example, in the research and development of new solar cells, this efficient charge transfer path can significantly improve the photoelectric conversion efficiency, enabling solar cells to more efficiently convert light energy into electrical energy.
[0027] 2. The orderly arrangement can also enhance the stability of the structure to a certain extent. External environmental factors such as temperature and humidity, as well as some physical collisions, often have adverse effects on the performance of materials. However, the two-dimensional perovskite quantum dot array structure, with its regular arrangement, can form a relatively stable architecture that effectively resists interference from external factors, thereby reducing the impact of external factors on optical performance and ensuring that it can still maintain excellent performance in various complex environments. Just like in some special lighting equipment working in extreme environments, it can still emit light stably even in the face of high temperature, high humidity or strong vibration.
[0028] 3. Its unique two-dimensional array structure has a significant effect on improving the quantum yield of luminescence. This structure can optimize the recombination efficiency of electrons and holes, making the luminescence process more efficient. It stands out among many luminescent materials and provides strong support for achieving high-brightness and high-purity luminescence. For example, in the manufacture of high-definition display screens, the use of this material can present brighter and clearer images with higher color reproduction, giving users an ultimate visual experience.
[0029] 4. The array structure gives the material better mechanical properties. In practical applications, the material may face various mechanical stresses such as stretching, bending, and extrusion. Traditional perovskite quantum dot materials are often easily damaged in these situations, while the two-dimensional perovskite quantum dot array structure, due to its special structure, can better withstand these stresses and adapt to more application scenarios. In the field of wearable electronic devices, such as smart bracelets, flexible display screens and other products, it can flexibly deform with the movement of the human body while maintaining its excellent performance, providing a solid foundation for the development of future smart wearable devices. Whether in the field of flexible electronic devices or in special equipment that needs to withstand complex mechanical environments, it has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1A low-magnification transmission electron microscope morphology image of a two-dimensional perovskite quantum dot array obtained in a method for preparing a two-dimensional perovskite quantum dot array according to the present invention;
[0031] Figure 2 This is an enlarged transmission electron microscope morphology image of a two-dimensional perovskite quantum dot array obtained in a method for preparing a two-dimensional perovskite quantum dot array according to the present invention;
[0032] Figure 3 A fluorescence image of a two-dimensional perovskite quantum dot array obtained in a method for preparing a two-dimensional perovskite quantum dot array according to the present invention;
[0033] Figure 4 This is an absorption diagram of a two-dimensional perovskite quantum dot array obtained in a method for preparing a two-dimensional perovskite quantum dot array according to the present invention. DETAILED DESCRIPTION
[0034] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.
[0035] Example 1
[0036] A method for preparing a two-dimensional array of perovskite quantum dots comprises the following steps:
[0037] S1: Prepare precursor solution A
[0038] 0.32 mmol of cesium bromide, 0.4 mmol of lead bromide, 0.1 mmol of potassium bromide, 0.8 mL of oleylamine, 0.8 mL of oleic acid, and 10 mL of dimethylformamide were fully mixed, stirred for 30 min at 70°C and 500 rpm to obtain a perovskite quantum dot precursor solution A with a concentration of 0.0195 g / mL.
[0039] S2: Preparation of K:CsPbBr3 perovskite quantum dot B solution
[0040] Take 10 mL of toluene and stir it at a speed of 800 rpm, heat 2 mL of precursor solution A to 30° C., and add precursor solution A to toluene while keeping toluene stirring to obtain K:CsPbBr3 perovskite quantum dot B solution.
[0041] S3: purifying the perovskite quantum dot B solution once to obtain a purified K:CsPbBr3 perovskite quantum dot C solution;
[0042] 3 mL of the prepared S2 solution was taken, 6 mL of ethyl acetate was added thereto, and centrifugation was performed at a speed of 5000 rpm for 3 min. Subsequently, the obtained precipitate was added to n-hexane for dispersion again, and finally a clean K:CsPbBr3 perovskite quantum dot solution was successfully obtained.
[0043] S4: preparing a two-dimensional perovskite K:CsPbBr3 ore quantum dot array D solution;
[0044] At a temperature of 32°C and a humidity of 54%, the light source was 30 cm away from the K:CsPbBr3 perovskite quantum dot C solution. The perovskite quantum dot C solution was irradiated for 390 minutes with a lamp power of 50 W. The light source was a 254 nm ultraviolet lamp. The K:CsPbBr3 perovskite quantum dot C solution was self-assembled into a two-dimensional K:CsPbBr3 perovskite quantum dot array D solution by light-induced self-assembly.
[0045] S5: Centrifugally purify the K:CsPbBr3 perovskite quantum dot array D solution once to obtain a clean K:CsPbBr3 perovskite quantum dot two-dimensional array solution.
[0046] Take 5 mL of the solution prepared by S4, add 10 mL of ethyl acetate into it, and centrifuge at a speed of 6000 rpm for 6 minutes. Then, add the obtained precipitate into toluene and disperse it again, and finally successfully obtain a clean two-dimensional K:CsPbBr3 perovskite quantum dot array solution.
[0047] Through TEM characterization of the K:CsPbBr3 perovskite quantum dot two-dimensional array, it was found that the length of the quantum dot two-dimensional array exceeded 500 microns, but the width was only 3-5 rows of quantum dots ( Figure 1 ,2). Since the average size of quantum dots is only 5nm, it means that there are at least 300-500 K:CsPbBr3 perovskite quantum dots forming the discovered quantum dot two-dimensional array. Through fluorescence spectroscopy characterization, it was found that the fluorescence peak of the K:CsPbBr3 perovskite quantum dot two-dimensional array is 456nm, and the half-peak width is 38nm ( Figure 3 ), demonstrating that K:CsPbBr3 perovskite quantum dot two-dimensional arrays can be used as excellent lighting or display materials, with absorption peaks at 428 and 454nm ( Figure 4 ).
[0048] Example 2
[0049] A method for preparing a two-dimensional array of perovskite quantum dots comprises the following steps:
[0050] S1: Prepare precursor solution A
[0051] 0.32mmol of cesium chloride, 0.4mmol of lead chloride, 0.1mmol of potassium chloride, 0.6mL of oleylamine, 0.9mL of oleic acid,
[0052] 0.5 mL of trioctylphosphine, 8 mL of dimethylformamide and 2 mL of dimethyl sulfoxide were fully mixed, stirred for 60 min at 90° C. and 300 rpm to obtain a perovskite quantum dot precursor solution A with a concentration of 0.0143 g / mL.
[0053] S2: Preparation of perovskite K: CsPbCl3 ore quantum dot B solution
[0054] Take 10 mL of toluene and stir it at a speed of 800 rpm, heat 2 mL of precursor solution A to 50° C., and add precursor solution A to toluene while keeping toluene stirring to obtain K:CsPbCl3 perovskite quantum dot B solution.
[0055] S3: purifying the K:CsPbCl3 perovskite quantum dot B solution once to obtain a purified perovskite quantum dot C solution;
[0056] 3 mL of the prepared S2 solution was taken, 6 mL of ethyl acetate was added thereto, and centrifugation was performed at a speed of 5000 rpm for 3 min. Subsequently, the obtained precipitate was added to n-hexane for dispersion again, and finally a clean perovskite quantum dot C solution was successfully obtained.
[0057] S4: Preparation of two-dimensional K:CsPbCl3 perovskite quantum dot array D;
[0058] At a temperature of 32°C and a humidity of 55%, the light source was 25 cm away from the K:CsPbCl3 perovskite quantum dot C solution. The perovskite quantum dot C solution was irradiated for 240 minutes with a lamp power of 36 W. The light source was a solar simulator. The K:CsPbCl3 perovskite quantum dot C solution was self-assembled into a two-dimensional K:CsPbCl3 perovskite quantum dot array D solution by light-induced self-assembly.
[0059] S5: Centrifugally purify the K:CsPbCl3 perovskite quantum dot array D solution once to obtain a clean K:CsPbCl3 perovskite quantum dot two-dimensional array solution.
[0060] Take 5 mL of the solution prepared by S4, add 7.5 mL of ethyl acetate into it, and centrifuge at a speed of 5000 rpm for 4 minutes. Then, add the obtained precipitate into toluene and disperse it again, and finally successfully obtain a clean two-dimensional K:CsPbCl3 perovskite quantum dot array solution.
[0061] Example 3
[0062] A method for preparing a two-dimensional array of perovskite quantum dots comprises the following steps:
[0063] S1: Prepare precursor solution A
[0064] 0.30 mmol of cesium iodide, 0.3 mmol of lead iodide, 0.15 mmol of rubidium iodide, 0.6 mL of oleylamine, 1 mL of oleic acid, 7 mL of dimethylformamide and 3 mL of dimethyl sulfoxide were fully mixed, stirred for 30 min at 60°C and 600 rpm to obtain a perovskite quantum dot precursor solution A with a concentration of 0.0213 g / mL.
[0065] S2: Preparation of Rb:CsPbI3 perovskite quantum dot B solution
[0066] Take 10 mL of toluene and stir it at a speed of 800 rpm, heat 2 mL of precursor solution A to 75° C., and add precursor solution A to toluene while keeping toluene stirring to obtain Rb:CsPbI3 perovskite quantum dot B solution.
[0067] S3: purifying the Rb:CsPbI3 perovskite quantum dot B solution once to obtain a purified perovskite quantum dot C solution;
[0068] 3 mL of the prepared S2 solution was taken, 6 mL of ethyl acetate was added thereto, and centrifugation was performed at a speed of 6000 rpm for 5 min. Subsequently, the obtained precipitate was added to n-hexane for dispersion again, and finally a clean Rb:CsPbI3 perovskite quantum dot solution was successfully obtained.
[0069] S4: preparing two-dimensional Rb:CsPbI3 perovskite quantum dot array D solution;
[0070] At a temperature of 32°C and a humidity of 53%, the light source was 15 cm away from the Rb:CsPbI3 perovskite quantum dot C solution. The Rb:CsPbI3 perovskite quantum dot C solution was irradiated for 120 minutes with a lamp power of 20 W. The light source was infrared light. The Rb:CsPbI3 perovskite quantum dot C solution was self-assembled into a two-dimensional Rb:CsPbI3 perovskite quantum dot array D solution by light-induced self-assembly.
[0071] S5: Centrifugally purify the Rb:CsPbI3 perovskite quantum dot array D solution once to obtain a clean Rb:CsPbI3 perovskite quantum dot two-dimensional array solution.
[0072] Take 3 mL of the solution prepared by S4, add 5 mL of ethyl acetate into it, and centrifuge at a speed of 5000 rpm for 5 minutes. Then, add the obtained precipitate into toluene and disperse it again, and finally successfully obtain a clean two-dimensional Rb:CsPbI3 perovskite quantum dot array solution.
[0073] Note: In actual operation, temperature control needs to be extremely precise. Even a slight deviation may lead to unsatisfactory reaction results. For example, the amount of various reagents added must be strictly in accordance with the predetermined amount. If there is a slight mistake, the expected product may not be obtained.
Claims
1. A method for preparing a two-dimensional array of perovskite quantum dots, characterized in that: The specific steps are as follows: S1: prepare precursor solution A; S2: Synthesize perovskite quantum dot B solution; S3: purifying the perovskite quantum dot solution B once to obtain a purified perovskite quantum dot solution C; S4: preparing a two-dimensional perovskite quantum dot array D solution; S5: Centrifugally purify the perovskite quantum dot array D solution once to obtain a clean perovskite quantum dot two-dimensional array solution.