A preparation method of perovskite nanoparticles based on B-site cation adsorption strategy

Abstract

The present invention provides a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy, belonging to the field of nanomaterials, and comprising the following steps: preparing nanoparticles as a base material; subjecting the base material to a thiol treatment; mixing a precursor solution containing B-site cations with the thiol-treated base material, and utilizing the strong adsorption of the thiol group to tightly attach the B-site cations to the surface of the base material to obtain a B-site cation structure; mixing a precursor solution containing A-site cations with the product of step 3, and then allowing the A-site cations to coordinate with the B-site cations to react, thereby achieving coordinated growth of perovskite quantum dots on the surface of the base material; and performing inert shell coating using an atomic layer deposition system. The present invention provides a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy, which meets the requirements of ALD dense shell coating and improves the stability of perovskite quantum dots.

Description

Technical Field

[0001] The present invention belongs to the field of nanomaterials, and more specifically, relates to a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy. Background Art

[0002] Perovskite quantum dots (PQDs) are a promising class of optoelectronic display materials developed in recent years. Due to their numerous advantages, including high brightness range, wide color gamut, long-range charge carrier diffusion, narrow luminescence half-width (FWHM ≈ 20 nm), high defect tolerance, tunable band gap, and ease of synthesis, they have attracted widespread attention from domestic manufacturers and researchers. They have shown remarkable application potential in a wide range of fields, including solar thin-film cells, luminescent fibers, multiphoton imaging, photodetection, and photocatalysis [1-4]. However, due to their intrinsic ionic salt properties, PQDs are extremely sensitive to external environmental conditions (such as humidity, temperature, polar solvents, light, and oxygen), and are easily affected by these conditions, leading to surface damage, phase transitions, and abnormal grain growth. In particular, when exposed to water and polar solvent systems, PQDs rapidly lose their structural integrity and optical properties within seconds, resulting in fluorescence quenching, which severely limits the practical application of PQD materials. Therefore, improving the stability and adaptability of PQDs in complex environmental conditions has been a hot topic in scientific research [5-9].

[0003] Atomic layer deposition (ALD) is an effective method for addressing the stability issues of perovskite quantum dots [10-11]. Conventionally synthesized perovskite quantum dots (QDs) are prone to steric hindrance on the substrate and grain surfaces, preventing the adsorption and deposition of precursor molecules. This results in numerous cracks and holes in the ALD shell during growth, significantly reducing the density. Therefore, developing novel ligand-free growth strategies for perovskite QDs is of great significance for the development of QD technology.

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[0013]

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[0014]

[11] B.Zhou, L.Qin, P.Wang, Z.Chen, J.Zang, J.Zhang, Y.Wen, R.Chen. Nanotechnology 2023, 34, 025203.

[0015]

[12] C.Y.You, F.M.Li, L.H.Lin, J.S.Lin, Q.Q.Chen, P.M.Radjenovic, Z.Q.Tian, J.F.Li. Nano Energy2020, 71, 104554. Summary of the Invention

[0016] The purpose of the present invention is to provide a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy, aiming to solve the technical problem in the prior art that the density of the atomic layer deposition shell cannot meet the use requirements.

[0017] In the early stage, the inventors invented a method for synthesizing perovskite nanoparticles with dual protection of pore confinement and shell isolation (patent number ZL201910367132.0). The method used atomic layer deposition technology to achieve nanoscale coating of perovskite quantum dots, effectively isolating the influence of the environment on the perovskite quantum dots. Even in highly polar solvents such as water and ethanol, the perovskite quantum dots still have good dispersibility, which greatly improves the stability and practical application range of the perovskite quantum dots. However, the inventors found in their research that surface compatibility has a key influence on the density of the ALD shell

[12] . The surface of perovskite quantum dots synthesized by traditional methods is rich in a large number of organic ligands.

[0018] To achieve the above object, the technical solution adopted by the present invention is to provide a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy, comprising the following steps:

[0019] Step 1, preparing nanoparticles as a base material;

[0020] Step 2, performing thiol treatment on the base material;

[0021] Step 3: Mixing the precursor solution containing the B-site cation with the thiol-modified substrate material, and utilizing the strong adsorption of the thiol group to firmly attach the B-site cation to the surface of the substrate material to obtain a B-site cation structure;

[0022] Step 4: mixing a precursor solution containing A-site cations with the product of step 3, and then causing the A-site cations to coordinate with the B-site cations to react, thereby achieving coordinated growth of perovskite quantum dots on the surface of the substrate material;

[0023] Step 5: Use an atomic layer deposition system to perform inert shell coating.

[0024] Preferably, the preparation steps of step 2 include:

[0025] Step 2.1, adding 3-mercaptopropyltrimethoxysilane as a raw material to anhydrous ethanol to prepare a mercapto solution;

[0026] Step 2.2, mixing the thiol solution with the base material in step 1, and reacting for 6-12 hours using water as a solvent;

[0027] Step 2.3: Wash with anhydrous ethanol 3-5 times and dry to obtain a thiol-modified base material.

[0028] Preferably, the preparation steps of step 3 include:

[0029] Step 3.1, dissolving a certain concentration of BX2 in dimethylformamide to obtain a B-site cation precursor, wherein the B element is one or more of Pb, Sn, and Mn; and the X element is a halogen element;

[0030] Step 3.2: fully mix with the thiol-modified base material in step 2, react for a period of time, and then centrifuge and wash to obtain a base material with B-site cation adsorption.

[0031] Preferably, the preparation steps of step 4 include:

[0032] Step 4.1, dissolving a certain concentration of AX in dimethylformamide to obtain an A-site cation precursor, wherein the A element is one or more of Cs, MA, and FA; and the X element is a halogen element;

[0033] Step 4.2, fully mixing with the base material adsorbed with the B-site cation in step 3;

[0034] Step 4.3: After a period of reaction, vacuum drying or placing in a poor solvent is performed to achieve coordination growth of perovskite quantum dots.

[0035] Preferably, the preparation steps of step 5 include:

[0036] Step 5.1, dispersing the product powder prepared in step 4 in the reaction chamber;

[0037] Step 5.2, placing in an atomic layer deposition system preheated to 50-200°C;

[0038] Step 5.3: Alternately introduce aluminum source pulses and water source pulses, and then introduce inert gas for flushing after the aluminum source pulses and water source pulses. The source bottle temperature setting range is 10-35°C, the aluminum source pulse time is 0.1-0.5s, the inert gas purge time is 5-20s, the water source pulse time is 0.1-0.5s, the inert gas purge time is 5-20s, and the number of cycles is 10-200.

[0039] Preferably, the inert gas is one or more of nitrogen, argon and helium.

[0040] Preferably, the oxide inert shell layer is one or more of a silicon dioxide shell layer, an aluminum oxide shell layer, and a titanium dioxide shell layer.

[0041] Preferably, the base material is one or more of an inorganic material and a metal material.

[0042] Preferably, the preparation step of step 1 comprises: using tetraethoxysilane as a silicon source, ethanol as a solvent, and ammonia water to adjust the pH, and synthesizing a spherical base material with a diameter of 50 to 150 nm at a certain temperature.

[0043] The beneficial effect of the method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy provided by the present invention is that: compared with the existing technology, the method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy of the present invention, in order to solve the problem of the influence of the steric effect of ligand molecules on the ALD shell density, has been invented. This technology does not require the addition of any additional ligand molecules and is applicable to the surfaces of various substrate materials. It is a universal and general synthesis scheme. The preparation method is simple to operate, low in cost, and can achieve large-scale batch preparation. The perovskite nanoparticles prepared using this technology have excellent stability and can maintain high fluorescence emission intensity for a long time in highly polar solvents such as water and ethanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 Experimental steps of a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy provided in an embodiment of the present invention Figure 1 ;

[0046] Figure 2 Experimental steps of a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy provided in an embodiment of the present invention Figure 2 ;

[0047] Figure 3 Transmission electron microscope micrograph 1 of perovskite nanoparticles prepared by a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy provided by an embodiment of the present invention;

[0048] Figure 4Figure 2 shows a transmission electron microscope photo of perovskite nanoparticles prepared by a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy provided in an embodiment of the present invention; the transmission electron microscope image shows the state of the perovskite material after growth and coating. The core-shell structure indicates that the ALD coating has been completed and the coating is relatively uniform. The black part seen in the middle is the morphology of the perovskite quantum dot crystals distributed between the nano-silicon spheres and the alumina shell layer, indicating that it is feasible to use this scheme to coordinate the growth of perovskite quantum dots.

[0049] Figure 5 The X-ray diffraction patterns of titanium ore nanoparticles before and after ALD coating of aluminum oxide. Among them, SiO2-CsPbBr3 is the perovskite nanoparticles prepared in step 4, SiO2-CsPbBr3@AlO x These are the perovskite nanoparticles prepared in step 5. X-ray diffraction patterns reveal that the nanoparticles prepared in steps 4 and 5 exhibit significant perovskite crystal diffraction peaks, consistent with the positions indicated on the crystal plane on card PDF18-0364, confirming the integrity of the perovskite quantum dot crystal structure. The broad peak around 25° in the pattern is that of the SiO2 nanospheres. Due to the amorphous and thin alumina shell, no distinct diffraction peaks appear in the XRD pattern. The X-ray diffraction patterns provide evidence of the authenticity and correctness of the crystal structure of the nanoparticles synthesized in each step.

[0050] Figure 6 is the fluorescence spectrum of the sample in step 5;

[0051] Figure 7 These are digital photos of perovskite quantum dots with different emission wavelengths synthesized under different halogen coordination conditions under 365nm ultraviolet light;

[0052] Figure 8 The following are photos of the distribution of the sample in step 5 dispersed in a mixed solution of water and toluene under sunlight and ultraviolet light conditions;

[0053] Figure 9 The dynamic fluorescence spectrum data of the perovskite nanoparticles coated with the oxide inert shell layer of Example 1 and continuously stirred in water for 200 minutes;

[0054] Figure 10 This is a fluorescence photograph of the sample in step 5 immersed in water for a long time. DETAILED DESCRIPTION

[0055] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0056] Please also refer to Figures 1 to 9 The preparation method of perovskite nanoparticles based on the B-site cation adsorption strategy provided by the present invention is now described. The preparation method of perovskite nanoparticles based on the B-site cation adsorption strategy comprises the following steps:

[0057] Step S1, preparing nanoparticles as a base material;

[0058] The preparation steps of step S1 include: using tetraethoxysilane as a silicon source, ethanol as a solvent, and ammonia water to adjust the pH, and synthesizing a spherical base material with a diameter of 50 to 150 nm at a certain temperature.

[0059] The substrate material is one or more of inorganic materials (such as silicon oxide, titanium oxide, graphene, carbon fiber, etc.) and metal materials (such as gold, silver, etc.).

[0060] Step S2, performing thiol treatment on the base material;

[0061] The specific steps of step S2 may be:

[0062] Step S2.1, adding 3-mercaptopropyltrimethoxysilane as a raw material to anhydrous ethanol to prepare a mercapto solution;

[0063] Step S2.2: Mix the thiol solution with the base material in step S1, and react at room temperature for 6-12 hours using water as a solvent;

[0064] Step S2.3: Wash with anhydrous ethanol 3-5 times and dry to obtain a thiol-modified base material.

[0065] Step S3, mixing a precursor solution containing the B-site cation with the thiol-modified base material, and utilizing the strong adsorption of the thiol group to firmly attach the B-site cation to the surface of the base material to obtain a B-site cation structure;

[0066] The specific implementation steps of step S3 are:

[0067] Step S3.1: Dissolve a certain amount of BX2 in dimethylformamide to obtain a B-site cation precursor. The B element is one or more of Pb, Sn, and Mn; the X element is a halogen element; and the concentration of BX2 is in the range of 10-40 mM (millimoles per liter).

[0068] Step S3.2: Thoroughly mix with the thiol-modified substrate material from step S2, react for a period of time, and then centrifuge and rinse to obtain a substrate material with adsorbed cations at site B. The mixing time is 1-3 hours, more specifically 2 hours. The reaction time is 1-3 hours. The centrifugal rinsing conditions are: centrifugation at 11,000 rpm for 5 minutes, followed by rinsing with DMF, and repeat twice.

[0069] Step S4, mixing a precursor solution containing the A-site cations with the product of step 3, and then causing the A-site cations to coordinate with the B-site cations by coprecipitation or solvent evaporation, thereby achieving coordinated growth of perovskite quantum dots on the surface of the substrate material;

[0070] The specific implementation steps of step S4 may be:

[0071] Step S4.1: Dissolve a predetermined concentration of AX in dimethylformamide to obtain an A-site cation precursor, wherein the element A is one or more of Cs, MA, and FA; and the element X is a halogen element. The concentration of AX is in the range of 10-40 mM. Ensure that the ratio of the A-site cation to the B-site cation is approximately 1:1.

[0072] Step S4.2, fully mixing with the base material adsorbed with the B-site cation in step S3;

[0073] Step S4.3: After a period of reaction, vacuum drying or placement in a poor solvent is performed to achieve coordinated growth of perovskite quantum dots. The reaction time is 10-30 minutes. Poor solvents include, but are not limited to, toluene, chloroform, cyclohexane, and n-hexane.

[0074] The specific implementation steps of step S4 may be:

[0075] Step S5: using an atomic layer deposition system to perform inert shell coating to improve the stability of the perovskite nanoparticles.

[0076] Step 5.1, dispersing the product powder prepared in step 4 in the reaction chamber;

[0077] Step 5.2, placing in an atomic layer deposition system preheated to 50-200°C;

[0078] Step 5.3: Alternately introduce aluminum source pulses and water source pulses, and then introduce inert gas for flushing after the aluminum source pulses and water source pulses. The source bottle temperature setting range is 10-35°C, the aluminum source pulse time is 0.1-0.5s, the inert gas purge time is 5-20s, the water source pulse time is 0.1-0.5s, the inert gas purge time is 5-20s, and the number of cycles is 10-200.

[0079] The inert gas is one or more of nitrogen, argon and helium.

[0080] The oxide inert shell layer is one or more of a silicon dioxide shell layer, an aluminum oxide shell layer, and a titanium dioxide shell layer.

[0081] The present invention provides a method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy. Compared with the prior art, a perovskite quantum dot nanosynthesis technology with excellent surface compatibility is developed. By adsorbing B-site cations on the surface of a substrate material, ligand-free coordination growth of perovskite quantum dots on the surface of a nanomaterial is achieved to meet the requirements of ALD dense shell coating and improve the stability of the perovskite quantum dots. In order to solve the problem of the influence of the steric effect of ligand molecules on the density of the ALD shell, a perovskite quantum dot coordination synthesis technology based on the B-site ion adsorption strategy was invented. This technology does not require the addition of any additional ligand molecules and is applicable to the surfaces of various substrate materials. It is a universal and general synthesis scheme. The preparation method is simple to operate, low-cost, and can be prepared on a large scale. The perovskite nanoparticles prepared using this technology have excellent stability and can maintain high fluorescence emission intensity for a long time in highly polar solvents such as water and ethanol.

[0082] Example 1 is described by taking silicon dioxide as an example of the base material.

[0083] 1) Prepare silica (SiO2) nanoparticles as a substrate. Specifically, tetraethoxysilane (TEOS) was used as the silicon source, ethanol was used as the solvent, and ammonia was used to adjust the pH. Spherical silica nanoparticles with a diameter of 50-150 nm were synthesized at room temperature. Typical ingredients: 0.75 ml of tetraethoxysilane (analytical grade), 1.775 ml of ammonia (analytical grade), and 25 ml of anhydrous ethanol (analytical grade).

[0084] 2) The silica nanoparticles are thiolated, replacing other groups on the silica with thiol groups (-SH). Typically, 45 μl of MPTMS (3-mercaptopropyltrimethoxysilane) is added to 15 ml of anhydrous ethanol to create a thiol solution. This thiol solution is then mixed with 15 ml of the silica spheres from step 1 and allowed to react in 120 ml of water for 6-12 hours. The particles are then washed 3-5 times with anhydrous ethanol and dried to obtain the thiolated silica nanoparticles.

[0085] 3) Mixing the precursor solution containing the B-site cations with the thiolated substrate material, leveraging the strong adsorption properties of the thiol groups to tightly adhere the B-site cations to the substrate surface, yielding a monolayer or sub-monolayer structure of B-site cations. Specifically, 0.55g of PbBr2 was dissolved in 50ml of dimethylformamide (DMF) to yield the B-site cation precursor. Then, 7.5ml of the PbBr2 solution was thoroughly mixed with the thiolated silica particles from step 2. The mixture was stirred in a 55°C water bath for 25 minutes, followed by centrifugation to obtain Pb-ion-adsorbed silica nanospheres.

[0086] 4) A predetermined concentration of a site A cation precursor is mixed with the particles, and then, through coprecipitation or solvent evaporation, the site A cations react with the site B cations to achieve coordinated growth of perovskite quantum dots on the substrate surface. Specifically, 0.33 g of CsBr at a predetermined concentration is dissolved in 50 ml of dimethylformamide (DMF) to obtain the site A cation precursor. Then, 4.8 ml of the CsBr solution is thoroughly mixed with the silica particles adsorbed with the site B cations from step 3. After ultrasonication for ten minutes, the particles are dried under vacuum at 120°C to achieve coordinated growth of the perovskite quantum dots.

[0087] 5) Use the atomic layer deposition system to coat the inert shell to improve the stability of the perovskite nanoparticles. Specifically, the perovskite nanoparticle powder prepared in step 4) is dispersed in the reaction chamber, and then placed in the atomic layer deposition system preheated to 100°C, and the aluminum source pulse and the water source pulse are alternately introduced. After the aluminum source pulse and the water source pulse, an inert gas is introduced for flushing. The source bottle temperature is set to 10-35°C, the aluminum source pulse time is 0.1-0.5s, the inert gas purge is 5-20s, the water source pulse time is 0.1-0.5s, the inert gas purge is 5-20s, and the number of cycles is 10-200. The obtained particles are photographed by high-resolution transmission electron microscopy to obtain Figure 3 、 Figure 4 , obtained by X-ray diffractometer analysis Figure 5 .

[0088] More specifically, the inert gas can be one of nitrogen, argon, helium, etc. The inert gas has two functions: one is to serve as a carrier gas for the ALD precursor, helping the precursor source to better adhere to the substrate surface. The other function is to purge and clean. In each small cycle, the excess gas in the reaction chamber must be removed to ensure that the oxidation reaction only occurs on the surface of the substrate material. The oxide inert shell layer can be selected from one of the silica shell layer, the alumina shell layer, the titanium dioxide shell layer, etc. The silica shell layer can use a precursor such as tridimethylaminosilane (TDMAS, silicon source). The alumina shell layer can use a precursor such as trimethylaluminum (TMA, aluminum source). The titanium dioxide shell layer can use a precursor such as titanium tetrachloride (TiCl4, titanium source). The water source can also be replaced with ozone as an oxidation source.

[0089] ALD can deposit a variety of shell layers, each requiring a different precursor. For example, when depositing Al2O3, the corresponding precursor source is TMA, which provides the Al element (similarly, the corresponding precursor source for SiO2 is TDMAS). Water or ozone is the oxidant, reacting with TMA to form the Al2O3 shell.

[0090] ALD is a typical surface reaction process. For example, Al2O3 is deposited in a reaction chamber. The chamber is then purged repeatedly with inert gas to ensure the cleanliness of both the chamber and the substrate surface. A TMA precursor is then introduced. After the precursor adsorbs onto the substrate surface, an inert gas is passed through to purge the chamber, removing any excess precursor, leaving only the portion adsorbed on the substrate surface. Water or ozone is then introduced to oxidize the TMA to form Al2O3. Because TMA adsorbs only a thin layer on the substrate surface, the Al2O3 produced by the reaction is also confined to the substrate surface. This process is called a cycle, and the Al2O3 shell deposited in each cycle is only approximately 0.1 nm thick. Therefore, to achieve a thicker shell, the above process needs to be repeated. For example, 100 cycles can yield an Al2O3 shell of approximately 10 nm.

[0091] Example 2

[0092] Fluorescence spectroscopy analysis

[0093] 0.1 g of the perovskite nanoparticles in Example 1 was placed in a 5 ml centrifuge tube, 3 ml of water was added for ultrasonic dispersion, and then transferred to a quartz cuvette using a pipette, and photoluminescence data was collected using a fluorescence spectrometer. Figure 6 As can be seen, under 365nm light excitation, the oxide-inert shell-coated perovskite nanoparticles emit stable fluorescence with an emission peak at 517nm and a half-width of 23nm. The fluorescence intensity is high, the emission spectrum is narrow, and the color purity is high.

[0094] Example 3

[0095] The CsBr and PbBr2 used in Example 1 are replaced with the corresponding CsX and PbX2 as precursors, where X is Cl, Br, or I halogen element, and the operation is repeated to obtain perovskite nanoparticles of different compositions. Figure 7 As shown, from left to right, are digital photos of perovskite nanoparticles composed of CsPbBrCl2, CsPbBr3, and CsPbI3 dispersed in aqueous solution, with an excitation light source of 365nm. CsPbBrCl2 appears blue, CsPbBr3 appears green, and CsPbI3 appears red.

[0096] Example 4 Stability Test

[0097] Figure 8 The following images show perovskite nanoparticles coated with the oxide inert shell from Example 1, after being stored in a toluene-water two-phase interface solution for three days, illuminated by fluorescent light and then by UV light (365nm). The images clearly show that the inert shell-coated perovskite nanoparticles are more likely to disperse in the aqueous phase, demonstrating excellent hydrophilicity. Furthermore, they exhibit distinct bright green fluorescence under UV excitation, demonstrating the excellent hydrophilicity and stability of the perovskite nanoparticles prepared using this method.

[0098] Figure 9 The following is the dynamic fluorescence spectrum data of the perovskite nanoparticles coated with the oxide inert shell of Example 1 and continuously stirred in water for 200 minutes. The figure shows a comparison of the stability of the perovskite nanoparticles in water after four different numbers of inert shell deposition cycles (50, 100, 150, and 200). It can be clearly seen from the figure that the stability of the perovskite nanoparticles in water is significantly improved with the increase in the number of shell deposition cycles (perovskite nanoparticles not coated with the shell will experience fluorescence quenching the moment they come into contact with water). When the number of deposition cycles reaches 200, the fluorescence intensity of the perovskite nanoparticles in water hardly decreases, indicating that this technology can significantly improve the stability of perovskite quantum dot materials.

[0099] Figure 10 This is the luminescence of the perovskite nanoparticles coated with the oxide inert shell of Example 1 after 90 days of dispersion in water. It can be seen that the ions coated with 200 layers still have strong fluorescence brightness after 90 days in water. Compared with the existing technology, the product of this application has better surface compatibility and meets the requirements of ALD dense shell coating, which can significantly improve the stability of perovskite quantum dots.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing perovskite nanoparticles based on a B-site cation adsorption strategy, characterized in that: The following steps are involved: Step 1, preparing nanoparticles as a base material; Step 2, performing thiol treatment on the base material; Step 3: Mixing the precursor solution containing the B-site cations with the thiol-modified base material, and utilizing the strong adsorption of the thiol groups to firmly attach the B-site cations to the surface of the base material, thereby obtaining a B-site cation-adsorbed base material; include: Step 3.1, dissolving a certain concentration of BX2 in dimethylformamide to obtain a precursor solution containing B-site cations, wherein B is one or more of Pb, Sn, and Mn; and X is a halogen element; Step 3.2, fully mixing the precursor solution containing the B-site cation with the thiol-modified base material in step 2, reacting for a period of time, and then centrifuging and washing to obtain the base material adsorbed with the B-site cation; Step 4: mixing a precursor solution containing A-site cations with the product of step 3, and then causing the A-site cations to coordinate with the B-site cations to react, thereby achieving coordinated growth of perovskite quantum dots on the surface of the substrate material; Step 4.1, dissolving a certain concentration of AX in dimethylformamide to obtain a precursor solution containing an A-site cation, wherein A is one or more of Cs, methylammonium MA, and formamidine FA; and X is a halogen element; Step 5: using an atomic layer deposition system to coat the inert shell; The inert shell layer is one or more of a silicon dioxide shell layer, an aluminum oxide shell layer, and a titanium dioxide shell layer.

2. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 1, wherein: The preparation steps of step 2 include: Step 2.1, adding 3-mercaptopropyltrimethoxysilane as a raw material to anhydrous ethanol to prepare a mercapto solution; Step 2.2, mixing the thiol solution with the base material in step 1, and reacting for 6-12 hours using water as a solvent; Step 2.3: Wash with anhydrous ethanol 3-5 times and dry to obtain a thiol-modified base material.

3. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 2, wherein: The preparation steps of step 4 also include: Step 4.2, the precursor solution containing the A-site cation is fully mixed with the base material adsorbed with the B-site cation in step 3; Step 4.3: After a period of reaction, vacuum drying or placing in a poor solvent is performed to achieve coordination growth of perovskite quantum dots.

4. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 3, wherein: The preparation steps of step 5 include: Step 5.1, dispersing the product powder prepared in step 4 in the reaction chamber; Step 5.2, placing in an atomic layer deposition system preheated to 50-200°C; Step 5.3: Alternately introduce aluminum source pulses and water source pulses, and then introduce inert gas for flushing after the aluminum source pulses and water source pulses. The source bottle temperature setting range is 10-35°C, the aluminum source pulse time is 0.1-0.5 s, the inert gas purge time is 5-20 s, the water source pulse time is 0.1-0.5 s, the inert gas purge time is 5-20 s, and the number of cycles is 10-200.

5. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 4, wherein: The inert gas is one or more of nitrogen, argon and helium.

6. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 1, wherein: The base material is an inorganic material.

7. The method for preparing perovskite nanoparticles based on the B-site cation adsorption strategy according to claim 6, characterized in that: The preparation steps of step 1 include: using tetraethoxysilane as a silicon source, ethanol as a solvent, and ammonia water to adjust the pH, and synthesizing a spherical base material with a diameter of 50 to 150 nm at a certain temperature.

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