WO2023087449A1

WO2023087449A1 - Manganese-doped organic perovskite cluster material and preparation method therefor

Info

Publication number: WO2023087449A1
Application number: PCT/CN2021/137717
Authority: WO
Inventors: 薛冬峰; 徐珂; 王晓明
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2021-11-17
Filing date: 2021-12-14
Publication date: 2023-05-25
Also published as: CN114106817B; CN114106817A

Abstract

A manganese-doped organic perovskite cluster material and a preparation method therefor. The preparation method comprises: dissolving AX and PbX2 in a solvent to obtain a first mixed solution, A being a monovalent organic cation, X being a halogen anion, and the molar weight of PbX2 being greater than that of AX; adding an organic carboxylic acid, an organic amine and a divalent manganese metal salt into the mixed solution to obtain a precursor solution, the molar ratio of the divalent manganese metal salt to PbX2 being 0.05-0.65:1; and mixing the precursor solution and an anti-solvent, and then performing solid-liquid separation to obtain a manganese-doped organic perovskite cluster material. The described preparation method has the characteristics of solution processing, rapid synthesis and low costs, and can obtain a doped perovskite cluster material having uniform size and excellent stability and optical properties.

Description

Manganese-doped organic perovskite cluster material and preparation method thereof

technical field

The application belongs to the technical field of nanomaterials, and in particular relates to a manganese-doped organic perovskite cluster material and a preparation method thereof.

Background technique

Perovskite materials are a class of fluorescent semiconductor nanomaterials with uniform size and ^high color purity _. amine (MA ⁺ , CH ₃ NH ₃ ⁺ ), ethylamine (EA ⁺ , CH ₃ CH ₂ NH ₃ ⁺ ) or formamidine (FA ⁺ , CH(NH ₂ ) ₂ ⁺ ) ions, etc.; the B position is usually Divalent metal cation Pb ²⁺ ; X position is usually a monovalent halogen anion, such as I ^- , Br ^- , Cl ^- and F ^- . Regarding the doping of perovskite clusters, the A, B and X position ions in the perovskite cluster components are doped and replaced. For example, alkaline earth metal ions (such as Ba ²⁺ and Sr ²⁺ ), transition metal ions (such as Mn ²⁺ , Zn ²⁺ and Cd ²⁺ ) and trivalent metal ions (such as Fe ³⁺ and Bi ³⁺ ) etc. Substituting Pb ²⁺ in the perovskite cluster structure, in addition, mutual substitution between pseudohalogen ions (such as SCN ^- and BF ₄ ^- ) and halogen can also be realized.

By using different types and concentrations of doping ions to regulate the electronic energy level structure of perovskite clusters, change the components of undoped perovskite clusters, reduce the defects as non-radiative recombination centers, and improve their photoluminescence Quantum yield and light/thermal/humidity stability for efficient synthesis of doped perovskite clusters. Appropriate doping of perovskite clusters can introduce new electronic energy levels and produce special luminescent properties of doped ions, which can enhance the optical properties of perovskite clusters.

The synthesis of doped perovskite clusters is realized by occupying the A site, B site or X site for the dopant ions in the design of the experimental scheme. Among them, the doping substitution at the A site can increase the tolerance factor of the perovskite material and thereby improve the stability of its structure; the doping substitution at the B site can reduce the toxicity of Pb ²⁺ by adjusting the BX bond generated between the B site and the X site The stability of its structure can be improved; the doping substitution at the X site can tune the band gap of the perovskite cluster, thereby broadening the range of emission wavelengths. At present, divalent metal cations Mn ²⁺ have been partially doped in inorganic perovskite clusters CsPbBr ₃ , but the doping synthesis of organic perovskite clusters has not been reported yet.

Contents of the invention

The purpose of this application is to provide a method for preparing manganese-doped organic perovskite cluster materials, aiming at solving the technical problem of how to prepare manganese-doped organic perovskite clusters with excellent optical properties and stability.

In order to realize the above-mentioned application purpose, the technical scheme adopted in this application is as follows:

In a first aspect, the present application provides a method for preparing a manganese-doped organic perovskite cluster material, comprising the following steps:

Dissolving AX and PbX ₂ in a solvent to obtain a mixed solution; wherein, A is a monovalent organic cation, X is a halogen anion, and the molar weight of the PbX ₂ is greater than that of the AX;

adding an organic carboxylic acid, an organic amine, and a divalent manganese metal salt into the mixed solution to obtain a precursor solution; wherein, the molar ratio of the divalent manganese metal salt to the PbX ₂ is 0.05-0.65:1;

The precursor solution and the anti-solvent are mixed, and then solid-liquid separation is performed to obtain a manganese-doped organic perovskite cluster material.

The preparation method provided in this application is a method of realizing manganese-doped organic perovskite clusters by ligand-assisted reprecipitation. First, the raw materials AX and _PbX are mixed and dissolved in a solvent, and then organic carboxylic acids and organic amines are added to the surface Ligands and divalent manganese metal salts are used to prepare a perovskite precursor solution, and finally the precursor solution is added to an anti-solvent for reaction, and solid-liquid separation can obtain manganese-doped perovskite cluster materials. In this process, the addition of organic carboxylic acids and organic amines as surface ligands can passivate the surface defects of perovskite clusters with large specific surface area (S/V), while the addition of a certain proportion of divalent manganese metal salts not only introduces Mn ²⁺ doping replaces part of the highly toxic Pb ²⁺ in the perovskite cluster structure to reduce the toxicity of perovskite clusters, and at this ratio, the generation of perovskite cluster materials can be realized, and at the same time, through the perovskite cluster Energy transfer within the cluster showing dual-wavelength fluorescence emission from excitons (blue) and ⁴ T ₁ → ⁶ A ₁ transitions of Mn ²⁺ (orange), which also enhances its environmental stability in air and under light. stability. The preparation method has the characteristics of solution processing, rapid synthesis and low cost, and can obtain doped perovskite cluster materials with uniform size, excellent stability and optical properties.

In a second aspect, the present application also provides a manganese-doped organic perovskite cluster material, which is prepared by the preparation method described in the present application.

The manganese-doped organic perovskite cluster material provided by this application is prepared by the unique preparation method of this application. Therefore, based on the characteristics of the preparation method, the manganese-doped organic perovskite cluster material of the present application has the characteristics of uniform size, stability and excellent optical properties. And other device fields have good development and application prospects.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a schematic flow chart of the preparation method of the manganese-doped perovskite cluster material provided by the embodiment of the present application;

Fig. 2 is a schematic diagram of the manganese-doped perovskite cluster in the preparation method of the manganese-doped perovskite cluster material provided by the embodiment of the present application;

Fig. 3 is the ultraviolet absorption spectrum and the fluorescence emission spectrum figure of the perovskite cluster material prepared in embodiment 1;

Fig. 4 is the transmission electron microscope test figure of the perovskite cluster material prepared in embodiment 2;

Fig. 5 is the ultraviolet absorption spectrum and the fluorescence emission spectrum figure of the perovskite quantum dot prepared by comparative example 1;

Fig. 6 is an effect diagram of the fluorescence quantum yield stability test of the perovskite cluster materials prepared in Examples 1-4.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved in the present application clearer, the present application will be further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not intended to limit the present application.

In this application, the term "and/or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, A and/or B may mean: A exists alone, A and B exist simultaneously, and B exists alone Condition. Among them, A and B can be singular or plural. The character "/" generally indicates that the contextual objects are an "or" relationship.

In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items.

It should be understood that in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the order of execution, and some or all steps may be executed in parallel or sequentially, and the execution order of each process shall be based on its functions and The internal logic is determined and should not constitute any limitation to the implementation process of the embodiment of the present application.

Terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

The amount of the relevant components mentioned in the description of the embodiment of the application can not only refer to the specific content of each component, but also represent the proportional relationship between the amounts of each component. The scaling up or down of the content of the fraction is within the scope disclosed in the description of the embodiments of the present application.

The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be called the second XX, and similarly, the second XX can also be called the first XX. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features.

The embodiment of the present application provides a method for preparing a manganese-doped organic perovskite cluster material, as shown in Figure 1, including the following steps:

S01: Dissolving AX and PbX ₂ in a solvent to obtain a first mixed solution; wherein, A is a monovalent organic cation, X is a halogen anion, and the molar weight of PbX ₂ is greater than that of AX;

S02: adding organic carboxylic acid, organic amine and divalent manganese metal salt into the mixed solution to obtain a precursor solution; wherein, the molar ratio of divalent manganese metal salt to PbX ₂ is 0.05-0.65:1;

S03: Mix the precursor solution and anti-solvent, and then perform solid-liquid separation to obtain manganese-doped organic perovskite cluster materials.

The preparation method provided in the examples of this application is a method of realizing manganese-doped organic perovskite clusters by ligand-assisted reprecipitation. First, the raw materials AX and _PbX are mixed and dissolved in a solvent, and then organic carboxylic acid and organic Amine surface ligands and divalent manganese metal salts are used to prepare a perovskite precursor solution, and finally the precursor solution is added to an anti-solvent to react to form perovskite clusters, and solid-liquid separation can obtain manganese-doped perovskite clusters Material. In this process, the addition of surface ligand organic carboxylic acid and organic amine can passivate the surface defects of perovskite clusters with large specific surface area (S/V), and the addition of the above-mentioned specific ratio of divalent manganese metal salt not only passes Introduce Mn ²⁺ doping to replace part of the highly toxic Pb ²⁺ in the perovskite cluster structure to reduce the toxicity of perovskite clusters, and at this ratio, the generation of perovskite cluster materials can be realized, and at the same time through the perovskite Internal energy transfer of ore clusters, showing dual-wavelength fluorescence emission from excitons (blue) and ⁴ T ₁ → ⁶ A ₁ transitions of Mn ²⁺ (orange), which can also enhance its environmental stability in air and under light. in the stability. The preparation method has the characteristics of solution processing, rapid synthesis and low cost, and can obtain doped perovskite cluster materials with uniform size, excellent stability and optical properties.

Most of the manganese-doped synthetic perovskites reported so far are perovskite quantum dots rather than perovskite clusters. However, in the embodiment of the present application, better photoelectric conversion performance and stability are achieved by manganese doping organic perovskite clusters. It should be noted that, in the above preparation process, the molar weight of _PbX2 is greater than that of AX, which reduces the defect concentration of the system and promotes the formation of an ordered perovskite structure; while the molar ratio of divalent manganese metal salt to _PbX2 is 0.05～0.65:1, the application proves through experiments that if the divalent manganese metal salt is added too little, it will become a surface ligand passivation perovskite material, thereby synthesizing larger size perovskite quantum dots instead of perovskite Clusters, if too much divalent manganese metal salt is added, the reaction system will be unbalanced and the perovskite material cannot be synthesized; therefore, the unique manganese-doped organic perovskite clusters of this application can only be synthesized under the above-mentioned molar ratio conditions Material.

The above step S01 is a step of dissolving the raw materials AX and PbX ₂ . Wherein, X is selected from at least one of I ^- , Br ^- , Cl ^- and F ^- , and A is selected from at least one of CH ₃ NH ₃ ⁺ , CH ₃ CH ₂ NH ₃ ⁺ and CH(NH ₂ ) ₂ ⁺ kind. Therefore, AX is at least one of CH ₃ NH ₃ X, CH ₃ CH ₂ NH ₃ X or CH(NH ₂ ) ₂ X, and PbX ₂ is at least one of PbI ₂ , PbBr ₂ , PbCl ₂ and PbF ₂ .

The solvent can be selected from at least one of dimethylsulfoxide (DMSO), γ-butyrolactone (GBL), 1-methyl-2-pyrrolidone (NMP) and N,N-dimethylformamide (DMF). species, preferably dimethylsulfoxide or N,N-dimethylformamide. The solvate formed by the coordination between the perovskite precursor and the solvent will significantly affect the crystallization process of the perovskite, and then affect the crystal size, crystal phase structure and microscopic morphology of the perovskite. Moreover, the raw materials AX and PbX ₂ have a coordination effect with solvent molecules. According to the electron orbital arrangement theory, the lone pair of electrons on the Pb 6s ² orbital is easy to lose, so PbX ₂ appears as a Lewis acid, and contains O, S, N Polar aprotic solvents of equal elements such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) are Lewis bases. When PbX ₂ is dissolved in polar aprotic solvents such as N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), an acid-base reaction occurs to generate solvent compounds PbX ₂ ·DMF and PbX ₂ ·DMSO, thereby Make the perovskite better ordered.

In one embodiment, in the step of dissolving AX and PbX ₂ in a solvent, the molar ratio of AX and PbX ₂ is 0.25˜0.65:1, preferably 0.35˜0.55:1. In the precursor solution, the addition of PbX ₂ in the above ratio can further improve the photoelectric performance of the perovskite material. Specifically, the amount of the initial substance of PbX ₂ may be 0.25-0.3 mmol.

For example, put methylammonium bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in the above ratio in a transparent glass bottle equipped with a stirring bar, add dimethyl sulfoxide (DMSO) or N, N-dimethylformamide (DMF) solvent was mixed, and the solvent volume was 0.5 mL. Stir at room temperature for 20-30 minutes until completely dissolved.

After dissolving AX and PbX ₂ in the solvent to obtain a mixed solution, the initial concentration of PbX ₂ in the mixed solution may be 0.5-0.6 mol/L.

In the above step S02, the surface passivation ligand and the doped divalent manganese metal salt are added.

In one embodiment, the step of adding the organic carboxylic acid, the organic amine and the divalent manganese metal salt to the mixed solution comprises: first adding the organic carboxylic acid and the organic amine to the mixed solution, and then adding the divalent manganese metal salt. By first adding organic carboxylic acid and organic amine, a ligand environment is provided for the system, thereby increasing the solubility of the subsequently added divalent manganese metal salt, and promoting rapid dissolution to obtain a precursor solution.

Wherein, the organic carboxylic acid can be propionic acid, n-butyric acid, n-valeric acid, octadecanoic acid, octadecenoic acid, benzoic acid, phenylacetic acid, citric acid, ethylenediaminetetraacetic acid, tartaric acid and stearic acid At least one, preferably organic carboxylic acid is octadecenoic acid or phenylacetic acid. The organic amine may be at least one of octadecylamine, octadecylamine, benzylamine and phenethylamine, preferably the organic amine is octadecylamine or phenethylamine.

Specifically, the organic carboxylic acid is octadecenoic acid, and the organic amine may be octadecenylamine; or, the organic carboxylic acid is phenylacetic acid, and the organic amine is phenethylamine. Octadecenic acid and octadecenylamine act synergistically, and the octadecyl carbon chain above can well inhibit the orientation connection between crystal nuclei and small particles, thereby simplifying the nucleation-growth mechanism, and providing a convenient way for the synthesis of monodisperse nanoparticles Create conditions; the double bonds in the carbon chains of octadecenoic acid and octadecenamine interact with each other through π-π bonds to make adjacent carbon chains form an array, which plays a role in inhibiting orientation connection. However, the synergistic effect of phenylacetic acid and phenylethylamine ligands makes the prepared perovskite clusters have better stability against humidity and play the role of overall uniform passivation.

In one embodiment, in the step of adding the organic carboxylic acid and the organic amine into the mixed liquid, the molar ratio of the organic carboxylic acid, the organic amine to the PbX ₂ in the first mixed liquid is 0.15˜0.65:0.15˜0.65:1. Specifically, the ratio of the amount of organic carboxylic acid added to the amount of PbX ₂ substance is 0.15-0.65:1, preferably 0.25-0.45:1; the ratio of the amount of organic amine added to the amount of PbX ₂ substance is 0.15-0.65:1 , the preferred ratio is 0.25-0.45:1. Compared with perovskite quantum dots with the same amount of substances, perovskite cluster materials require more organic carboxylic acid and organic amine ligands to passivate surface defects due to their larger specific surface area (S/V), In order to obtain perovskite clusters with strong stability. Therefore, the reaction of organic carboxylic acid and organic amine ligand under the above ratio conditions, the ratio used is significantly higher than the ratio of perovskite quantum dots synthesized in the same amount, so that smaller size perovskite clusters can be generated .

Specifically, organic carboxylic acid and organic amine are added into the mixed solution according to the above ratio, stirred at room temperature for 20-30 minutes, fully dissolved, and then divalent manganese metal salt is added to dissolve to obtain a precursor solution.

The addition of the above-mentioned organic carboxylic acid and organic amine can not only generate smaller-sized perovskite clusters, but also reduce the direct contact of perovskite clusters to cause aggregation between clusters, and at the same time passivate the surface of perovskite clusters. The defects in turn improve the stability of the perovskite clusters against the external environment.

In the above process, the addition of divalent manganese metal salt is to provide dopant ions. Among them, the divalent manganese metal salt can be manganese fluoride (MnF ₂ ), manganese chloride (MnCl ₂ ), manganese bromide (MnBr ₂ ), manganese iodide (MnI ₂ ), manganese nitrate hexahydrate (Mn(NO ₃ ) ₂ ·6H ₂ O) and manganese acetate (C ₄ H ₆ MnO ₄ ), preferably manganese chloride (MnCl ₂ ) or manganese bromide (MnBr ₂ ), so that more Mn ²⁺ can be doped At the same time, the interference of anion doping can be excluded.

In the above process, the molar ratio of divalent manganese metal salt to PbX ₂ is 0.05-0.65:1, so that the unique manganese-doped organic perovskite cluster material of this application can be obtained. Further, the molar ratio of divalent manganese metal salt to PbX ₂ is 0.25-0.45:1.

Mn ²⁺ doping perovskite clusters can improve their optical properties and stability, which lies in the ionic radius of Mn ²⁺

Ionic radius smaller than that of Pb ²⁺

The binding energy of Mn-X is greater than that of Pb-X, which makes the perovskite octahedral structure more stable, so the purpose of effectively improving the stability and optical properties of perovskite clusters can be achieved.

Specifically, after adding the organic carboxylic acid and the organic amine into the mixed solution, add the divalent manganese metal salt into the mixed solution according to the above ratio, stir at room temperature for 20-30 minutes, and dissolve to obtain the perovskite cluster precursor solution .

In the above step S03, that is, the separation process of the manganese-doped organic perovskite cluster material.

Wherein, adding anti-solvent can be at least one in chlorobenzene, toluene, ethyl acetate, ether, methylene chloride, chloroform, octadecene (ODE), octadecane, tetradecane, paraffin oil and xylene species, preferably one of toluene and chloroform. Toluene and chloroform are more conducive to the preparation of perovskite cluster materials with strong dispersion and uniform size. Therefore, the preferred combination of solvent and anti-solvent in the examples of the present application is: DMF and toluene, or DMSO and chloroform.

In one embodiment, the volume ratio of the precursor solution and the anti-solvent is 0.1-0.7:3-7. For example, the volume of the anti-solvent is 3-7 mL, preferably 4-6 mL. The added volume of the precursor solution is 0.1-0.7 mL, preferably 0.2-0.5 mL. Under the above ratio conditions, not only the positive and negative solvents are compatible, but also the anti-solvent recrystallization method can be used to prepare perovskite cluster materials with reduced particle size, uniform particles and good dispersion.

Specifically, put the glass bottle containing the anti-solvent into the stirring bar on the stirring table, and then use a pipette to quickly inject the precursor solution into the anti-solvent at one time. Min rapid stirring for 1 to 2 minutes, the manganese-doped organic perovskite cluster solution can be preliminarily synthesized.

In one embodiment, the solid-liquid separation is centrifuged at a rotational speed of 7000-120000 r/min. Specifically, centrifugal separation is performed by a centrifuge. During the centrifugal washing and purification process, the centrifuge is set at a rotational speed of 7000-120000 r/min, preferably at a rotational speed of 8000-10000 r/min, and centrifuged for 15-20 min. Finally, the obtained perovskite clusters are stored in a refrigerator at low temperature (0-5° C.).

In the examples of this application, manganese-doped organic perovskite clusters were prepared by ligand-assisted reprecipitation. The structure of the manganese-doped organic perovskite clusters generated by the reaction is shown in Figure 2, and can be placed in a refrigerator for stability after synthesis. storage. It should be noted that after the precursor solution is obtained, it is necessary to ensure that it is ready-to-use every time, and the solution is completely dissolved without precipitation before performing subsequent anti-solvent mixing and solid-liquid separation steps.

In the above preparation method of the examples of the present application, by adopting the passivation strategy of organic carboxylic acid and organic amine surface ligands and the Mn ²⁺ doping substitution strategy, combined with the selection of a suitable perovskite system, the synthesis of B-site doped pure organic The purpose of perovskite clusters. Among them, the selection of suitable organic perovskite raw materials can be more conducive to the synthesis of purely doped perovskite clusters; surface ligands can improve the stability of perovskite clusters by passivating the surface defects of perovskite clusters. ; The Mn ²⁺ doping strategy can replace Pb ²⁺ in the perovskite cluster structure, reduce the toxicity of the perovskite cluster, and reduce the non-radiative recombination defects inside and on the surface of the perovskite cluster to improve its optical properties . Therefore, in the examples of the present application, high-quality manganese-doped organic perovskite clusters were successfully prepared by selecting different types and concentrations of Mn ²⁺ metal salts, organic carboxylic acids, and organic amines.

On the other hand, the embodiment of the present application also provides a manganese-doped organic perovskite cluster material, which is prepared by the above-mentioned preparation method in the embodiment of the present application.

The manganese-doped organic perovskite cluster material provided in the examples of the present application is prepared by the unique preparation method of the present application. Therefore, based on the characteristics of the preparation method, the manganese-doped organic perovskite cluster material in the embodiment of the present application has the characteristics of uniform size, stability and excellent optical performance, and is suitable for micro-nano light emitters, biological imaging, fluorescent labeling and Light-emitting diodes and other devices have good development and application prospects.

The following will be described in conjunction with specific embodiments.

Example 1

A manganese-doped organic perovskite cluster, the preparation of which comprises the steps of:

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely dissolved; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, and the volume of the solvent is 0.5mL; then, add octadecenoic acid and octadecenylamine and stir to dissolve, wherein, octadecenyl The ratio of the amount of acid added to lead bromide (PbBr ₂ ) is 0.45:1, the ratio of octadecenamine to lead bromide (PbBr ₂ ) is 0.45:1; stir at room temperature 20-30 minutes, fully dissolved; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), the molar ratio of divalent manganese metal salt to lead bromide (PbBr ₂ ) is 0.4:1, to obtain perovskite clusters The precursor solution;

②According to the volume ratio of precursor solution and anti-solvent toluene of 0.5:5, inject the perovskite cluster precursor solution into toluene, in which the volume of anti-solvent is 10mL; react at room temperature for 1-2min to obtain manganese-doped organic calcium Titanium cluster solution;

③ The perovskite cluster solution was subjected to centrifugal washing and purification treatment at a speed of 10000r/min, centrifuged for 20min, and centrifuged 3 times to separate manganese-doped organic perovskite clusters, and finally the obtained perovskite clusters The solution is stored in a refrigerator at a low temperature (0-5° C.), and the particle size of the perovskite cluster is 1.5-2.5 nm.

Example 2

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely Dissolve; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, wherein the volume of solvent is 0.5mL; then, add phenylacetic acid and phenethylamine and stir to dissolve, wherein, the addition amount of phenylacetic acid is the same as that of lead bromide (PbBr ₂ ) substance ratio is 0.45:1, the amount of phenethylamine added to lead bromide (PbBr ₂ ) substance ratio is 0.45:1; stir at room temperature for 20-30min to fully dissolve; finally, add Divalent manganese metal salt manganese bromide (MnBr ₂ ), the molar ratio of divalent manganese metal salt to lead bromide (PbBr ₂ ) is 0.4:1 to obtain a precursor solution of perovskite clusters;

③ The perovskite cluster solution was subjected to centrifugal washing and purification treatment at a speed of 10000r/min, centrifuged for 20min, and centrifuged 3 times to separate manganese-doped organic perovskite clusters, and finally the obtained perovskite clusters The solution is stored in a refrigerator at a low temperature (0-5° C.) for future use, wherein the particle size of the perovskite cluster is 2.1-2.9 nm.

Example 3

① Dissolve methyl ammonium bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in a dimethyl sulfoxide (DMSO) solvent at a ratio of 0.4:1 and stir until completely dissolved; The initial concentration of lead (PbBr ₂ ) is 0.6mol/L, and the volume of the solvent is 0.5mL; then, add octadecenoic acid and octadecenylamine and stir to dissolve, wherein, the addition amount of octadecenoic acid The ratio of the amount of octadecenylamine to lead bromide (PbBr ₂ ) is 0.45:1, and the ratio of octadecylamine to lead bromide (PbBr ₂ ) is 0.45:1; stir at room temperature for 20-30 minutes, Dissolve fully; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), the molar ratio of divalent manganese metal salt to lead bromide (PbBr ₂ ) is 0.4:1, and obtain the precursor solution of perovskite clusters ;

②According to the volume ratio of precursor solution and anti-solvent chloroform as 0.5:5, inject the perovskite cluster precursor solution into chloroform, in which the volume of anti-solvent is 10mL; react at room temperature for 1-2min to obtain manganese doped organic perovskite cluster solution;

③ The perovskite cluster solution was subjected to centrifugal washing and purification treatment at a speed of 10000r/min, centrifuged for 20min, and centrifuged 3 times to separate manganese-doped organic perovskite clusters, and finally the obtained perovskite clusters The solution is stored in a refrigerator at a low temperature (0-5° C.) for future use, wherein the particle size of the perovskite cluster is 1.9-2.5 nm.

Example 4

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely dissolved; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, and the volume of the solvent is 0.5mL; then, add octadecenoic acid and octadecenylamine and stir to dissolve, wherein, octadecenyl The ratio of the amount of acid added to lead bromide (PbBr ₂ ) is 0.45:1, the ratio of octadecenamine to lead bromide (PbBr ₂ ) is 0.45:1; stir at room temperature 20-30 minutes, fully dissolved; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), the molar ratio of divalent manganese metal salt to lead bromide (PbBr ₂ ) is 0.3:1, to obtain perovskite clusters The precursor solution;

Comparative example 1

A kind of manganese-doped organic perovskite, its preparation comprises the steps:

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely dissolved; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, and the volume of the solvent is 0.5mL; then, add octadecenoic acid and octadecenylamine and stir to dissolve, wherein, octadecenyl The ratio of the amount of acid added to lead bromide (PbBr ₂ ) is 0.45:1, the ratio of octadecenamine to lead bromide (PbBr ₂ ) is 0.45:1; stir at room temperature 20 to 30 minutes to fully dissolve; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), the molar ratio of divalent manganese metal salt to lead bromide (PbBr ₂ ) is 0.02:1 to obtain a precursor solution;

②According to the volume ratio of precursor solution and anti-solvent toluene is 0.5:5, inject the precursor solution into toluene, in which the volume of anti-solvent is 10mL; react at room temperature for 1-2min;

③The above solution was subjected to centrifugal washing and purification treatment at a rotational speed of 10,000r/min, centrifuged for 20min, and centrifuged 3 times, but manganese-doped organic perovskite clusters could not be obtained, and the product was perovskite quantum dots.

Comparative example 2

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely dissolved; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, and the volume of the solvent is 0.5mL; then, add octadecylamine and stir to dissolve, wherein, the amount of octadecylamine added is the same as that of bromine The mass ratio of lead (PbBr ₂ ) is 0.45:1; stir at room temperature for 20-30 minutes to fully dissolve; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), divalent manganese metal salt and bromide The molar ratio of lead (PbBr ₂ ) is 0.4:1, the precursor solution;

②According to the volume ratio of precursor solution and anti-solvent toluene is 0.5:5, inject the solution into toluene, in which the volume of anti-solvent is 10mL; react at room temperature for 1-2min;

Comparative example 3

①Dissolve methylamine bromide (CH ₃ NH ₃ Br ) and lead bromide (PbBr ₂ ) in N,N-dimethylformamide (DMF) solvent with a ratio of 0.4:1 and stir until completely Dissolve; the initial concentration of lead bromide (PbBr ₂ ) is 0.6mol/L, wherein the volume of solvent is 0.5mL; then, add octadecenoic acid and stir to dissolve, wherein, the addition amount of octadecenoic acid and bromine The mass ratio of lead (PbBr ₂ ) is 0.45:1; stir at room temperature for 20-30 minutes to fully dissolve; finally, add divalent manganese metal salt manganese bromide (MnBr ₂ ), divalent manganese metal salt and bromide The molar ratio of lead (PbBr ₂ ) is 0.4:1 to obtain a precursor solution;

Performance Testing:

1. The characteristic peaks of the ultraviolet absorption spectrum and the fluorescence emission spectrum of the perovskite cluster solution prepared in Example 1 were tested by means of a UV-visible spectrometer and a fluorescence spectrophotometer. The test results are shown in Figure 3, wherein the characteristic peak corresponding to the ultraviolet absorption spectrum is 411nm, which corresponds to the peak position of the perovskite cluster; the characteristic peaks corresponding to the fluorescence emission spectrum are 415nm and 585nm, respectively corresponding to the perovskite cluster and manganese ion doped characteristic peaks.

2. The shape and size of the perovskite clusters prepared in Example 2 were tested by a high-resolution transmission electron microscope testing instrument. The test results are shown in Figure 4, and the test results show that the manganese-doped perovskite clusters The clusters are spherical with an average size of 2.50±0.4 nm.

3. The characteristic peaks of the ultraviolet absorption spectrum and the fluorescence emission spectrum of the perovskite solution prepared in Comparative Example 1 were tested by means of an ultraviolet-visible spectrometer and a fluorescence spectrophotometer. The test results are shown in accompanying drawing 5, wherein, the characteristic peak corresponding to the ultraviolet absorption spectrum is 505nm, corresponding to the peak position of the perovskite quantum dot; the characteristic peak corresponding to the fluorescence emission spectrum is 507nm, corresponding to the characteristic peak of the perovskite quantum dot .

4. Carry out a stability test at an air temperature of 25° C. and a relative humidity of 65%. Through the integrating sphere of a fluorescence spectrophotometer tester, the manganese-doped perovskite cluster solution prepared in Examples 1 to 4, The fluorescence quantum yields of Comparative Example 2 without adding organic carboxylic acid and Comparative Example 3 without adding organic amine were tested, and the test results are shown in Table 1 below. It can be seen that the perovskite clusters prepared by adding a certain proportion of divalent manganese metal salt manganese bromide (MnBr ₂ ) in Examples 1 to 4 exhibited a relatively high initial value of fluorescence quantum yield, and remained stable after a week of continuous testing. It has a higher fluorescence quantum yield and shows better stability. However, the perovskite quantum dot materials prepared in Comparative Example 2 and Comparative Example 3 have very low fluorescence quantum yields and are easily quenched.

Table 1

the	荧光量子产率初始值％Fluorescence quantum yield initial value %	一个月后的荧光量子产率％Fluorescence quantum yield % after one month
实施例1Example 1	92％92%	85％85%

实施例2Example 2	90％90%	83％83%
实施例3Example 3	87％87%	79％79%
实施例4Example 4	84％84%	75％75%
对比例2Comparative example 2	6％6%	0％0%
对比例3Comparative example 3	2％2%	0％0%

Simultaneously to embodiment 1～4, by the integrating sphere of fluorescence spectrophotometer tester, the stability in isopropanol is tested, as shown in Figure 6, test result shows that along with the fluorescence quantum yield test of 24 hours , the fluorescence quantum yields of the perovskite clusters prepared in Examples 1 to 4 were reduced from the original 92%, 90%, 97% and 84% to 88%, 86%, 82% and 80%, showing good stability and luminescence properties.

The above descriptions are only preferred embodiments of the application, and are not intended to limit the application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the application should be included in the protection of the application. within range.

Claims

A method for preparing a manganese-doped organic perovskite cluster material, characterized in that it comprises the following steps:

Dissolving AX and PbX 2 in a solvent to obtain a mixed solution; wherein, A is a monovalent organic cation, X is a halogen anion, and the molar weight of the PbX 2 is greater than that of the AX;

adding an organic carboxylic acid, an organic amine, and a divalent manganese metal salt into the mixed solution to obtain a precursor solution; wherein, the molar ratio of the divalent manganese metal salt to the PbX 2 is 0.05-0.65:1;

The precursor solution and the anti-solvent are mixed, and then solid-liquid separation is performed to obtain a manganese-doped organic perovskite cluster material.
The preparation method according to claim 1, characterized in that, in the step of dissolving AX and PbX 2 in a solvent, the molar ratio of the AX to the PbX 2 is 0.25-0.65:1.
The preparation method according to claim 1, characterized in that, the step of adding organic carboxylic acid, organic amine and divalent manganese metal salt to the mixed solution comprises: first adding the organic carboxylic acid and the organic amine In the mixed solution, then add the divalent manganese metal salt.
The preparation method according to claim 3, characterized in that, in the step of adding the organic carboxylic acid and the organic amine to the mixed solution, the mixture of the organic carboxylic acid, the organic amine and the The molar ratio of PbX 2 in the liquid is 0.15-0.65:0.15-0.65:1.
The preparation method according to claim 1, wherein the volume ratio of the precursor solution to the anti-solvent is 0.1-0.7:3-7;

And/or the solid-liquid separation includes centrifugal separation at a rotational speed of 7000-120000 r/min.
The preparation method according to any one of claims 1-5, characterized in that X is selected from at least one of I - , Br - , Cl - and F - , and A is selected from CH 3 NH 3 + , CH 3 At least one of CH 2 NH 3 + and CH(NH 2 ) 2 + .
The preparation method according to any one of claims 1-5, wherein the divalent manganese metal salt is selected from the group consisting of manganese fluoride, manganese chloride, manganese bromide, manganese iodide, manganese nitrate hexahydrate and acetic acid at least one of manganese.
The preparation method according to any one of claims 1-5, wherein the organic carboxylic acid is selected from propionic acid, butyric acid, pentanoic acid, octadecanoic acid, octadecenoic acid, benzoic acid, phenylacetic acid , at least one of citric acid, ethylenediaminetetraacetic acid, tartaric acid and stearic acid;

And/or the organic amine is at least one selected from octadecylamine, octadecenylamine, benzylamine and phenethylamine.
The preparation method according to any one of claims 1-5, wherein the solvent is selected from dimethyl sulfoxide, γ-butyrolactone, 1-methyl-2-pyrrolidone and N,N-di at least one of methylformamide;

And/or the anti-solvent is selected from at least one of chlorobenzene, toluene, ethyl acetate, ether, methylene chloride, chloroform, octadecene, octadecane, tetradecane, paraffin oil and xylene .
A manganese-doped organic perovskite cluster material, characterized in that the manganese-doped organic perovskite cluster material is prepared by the preparation method described in any one of claims 1-9.