CN115717071A

CN115717071A - Perovskite quantum dot composite material and preparation method and application thereof

Info

Publication number: CN115717071A
Application number: CN202110997935.1A
Authority: CN
Inventors: 韩登宝; 李飞; 景宇宇; 钟海政
Original assignee: Zhijing Technology Beijing Co ltd; Hefei Innovation Research Institute of Beihang University
Current assignee: Zhijing Technology Beijing Co ltd; Hefei Innovation Research Institute of Beihang University
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2023-02-28

Abstract

The invention provides a perovskite quantum dot composite material and a preparation method and application thereof, wherein the perovskite quantum dot composite particles comprise a coating material and perovskite quantum dot particles; the coating material coats the perovskite quantum dot composite particles; the coating material comprises a polymer with high water oxygen barrier rate; the perovskite quantum dot composite particles comprise perovskite quantum dots. According to the invention, the perovskite quantum dots are coated in situ by a spray drying method, so that the damage to the quantum dot material in the traditional liquid phase coating method is avoided, and the application range of the perovskite quantum dot composite material is widened; the preparation process is simple, the equipment cost is low, the repeatability is high, and the method is suitable for industrial large-scale production and popularization.

Description

Perovskite quantum dot composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of display, in particular to a perovskite quantum dot composite material and a preparation method and application thereof.

Background

The quantum dot material is a semiconductor nanocrystal with three-dimensional dimensions all in nanometer scale, and can emit light with different colors according to different components and dimensions when being subjected to photoelectric stimulation. The quantum dots can be used as a pure light source, so that the display color gamut of the display device can be greatly improved, and the quantum dots become a development trend of a novel display technology and have been successfully commercialized. Display manufacturers such as samsung, TCL, and haixin have all introduced high-end television products with quantum dot materials. Common quantum dot materials comprise II-VI cadmium quantum dots and III-V indium phosphide quantum dots, and the synthesis of the common quantum dot materials needs complex high-temperature chemical reaction and generates a large amount of waste liquid, so that the material cost is very high. The perovskite quantum dot material is a novel semiconductor luminescent material, has optical performance comparable to that of the traditional quantum dot, and has a very simple preparation process, so that the perovskite quantum dot material becomes one of candidate material systems for luminescent application.

At present, the luminescent thin film prepared in situ based on perovskite quantum dots has been successfully applied to the backlight of the liquid crystal television, the display color gamut can be effectively increased to 105% NTSC, and the commercial application is successfully realized. However, since research starts later, there is still a key problem to be solved that the perovskite quantum dot material has a distance to realize exceeding that of other quantum dot materials, that is, the reliability of the quantum dot material under actual working conditions meets the requirements of industrial application, however, the stability of the perovskite quantum dot in actual application is gradually reduced, so that the application is limited, and the requirements cannot be met. Among them, the main reason for the reduction of the perovskite quantum dot stability is water oxygen intrusion in the working environment, which causes fluorescence quenching of the quantum dot, and this is one of the challenges faced by all quantum dot materials. The existing solution is to prepare a composite film of quantum dots and polymers, and to add a layer of barrier film with high water oxygen barrier rate on both sides of the composite film to form a sandwich protective structure, so that the process becomes more complex and the cost becomes more expensive.

Disclosure of Invention

The invention provides an in-situ coating technology of a perovskite quantum dot composite material. According to the technology, the perovskite quantum dot particles are prepared by synchronously spray-drying through multi-nozzle spray-drying equipment, and compared with the traditional liquid-phase method solution coating and atomic layer deposition coating, the process flow is simpler, continuous and stable. In the preparation process of the perovskite quantum dot particles, a polymer protective layer with excellent water and oxygen barrier property is coated in situ to block the invasion of water and oxygen, so that the stability of the perovskite quantum dot particles is improved. The damage effect and the complicated cleaning link of a large amount of organic solvents used in the traditional liquid phase method solution coating method to the quantum dot material are avoided, and the problem of incomplete atomic layer deposition coating caused by polymer bonding aggregation is solved.

The main spray head is arranged at the center of the top of the drying tank body, and other spray heads are arranged on the side wall of the drying tank body lower than the main spray head. The perovskite quantum dot/polymer micro-liquid drop atomized by the main nozzle preferentially contacts hot air to be primarily dried and formed, and then contacts with the coating material liquid drop atomized by other coating nozzles to realize the effective coating of the surface of the perovskite quantum dot/polymer micro-liquid. The micro-droplets atomized by the main nozzle need to be dried preferentially and then contact with the micro-droplets atomized by the coating nozzle, so that the perovskite quantum dot composite material and the coating material are in a core-shell structure.

According to one aspect of the present invention, a method of preparing a perovskite quantum dot composite is provided.

A preparation method of a perovskite quantum dot composite material comprises the steps of atomizing a solution II containing a coating material, spraying the solution II on perovskite quantum dot composite particles, drying, reacting, and forming a coating layer on the surfaces of the perovskite quantum dot composite particles to obtain the perovskite quantum dot composite material.

Optionally, the preparation method comprises:

(1) And (3) atomizing and drying the solution I containing the perovskite quantum dot precursor and the polymer to obtain the perovskite quantum dot composite particles.

(2) And atomizing a solution II containing a coating material, spraying the solution II on the surface of the perovskite quantum dot composite particle, drying and reacting to form a coating layer on the surface of the perovskite quantum dot composite particle, thereby obtaining the perovskite quantum dot composite material.

Optionally, the perovskite quantum dot precursor comprises a first precursor, a second precursor and a compound c.

Optionally, the solution I containing the perovskite quantum dot precursor and the polymer is atomized and then dried by hot air at 50-200 ℃ to obtain the perovskite quantum dot composite particles.

The chemical formula of the first precursor is shown as formula III:

AX is of the formula III.

Wherein A is selected from NH ₂ CHNH ₂ ⁺ 、CH ₃ NH ₃ ⁺ 、Cs ⁺ 、Rb ⁺ 、Ag ⁺ At least one of (1).

X is at least one selected from anions of halogen elements.

The chemical formula of the second precursor is shown as formula V:

BX _t formula V.

Wherein B is selected from Pb ²⁺ 、Cd ²⁺ 、Mn ²⁺ 、Zn ²⁺ 、Sn ²⁺ 、Ge ²⁺ 、Bi ³⁺ 、In ³⁺ At least one of (1).

t＝2～3。

The compound c is selected from at least one of oleic acid, oleylamine, oleic acid bromine and Xin An bromine.

Optionally, the polymer is selected from at least one of polyvinylidene fluoride, polyvinylidene fluoride and trifluoroethylene copolymer, polyacrylonitrile, polyvinyl acetate, cellulose acetate, cyano cellulose, polysulfone, aromatic polyamide, polyimide, polycarbonate, polystyrene, polymethyl methacrylate.

Optionally, in the perovskite composite particle, the polymer coats the perovskite quantum dots.

Optionally, the mass ratio of the quantum dot precursor to the polymer is 1:5-500.

Alternatively, the mass ratio of the quantum dot precursor to the polymer is 1:5, 1:6, 1:7, 1:8, 1:9, 1.

Optionally, the mass ratio of the quantum dot precursor to the polymer is 1.

Alternatively, the mass ratio of the quantum dot precursor to the polymer is 1.

Optionally, the solution I further comprises a solvent I. The solvent I is an organic solvent.

Optionally, the organic solvent is selected from at least one of N, N-dimethylformamide, dimethyl sulfoxide, N-hexane, octadecene, trimethyl phosphate, triethyl phosphate, N-methylpyrrolidone, and dimethylacetamide.

Optionally, the concentration of the titanium ore quantum dot precursor in the solution I is 0.0001-0.01.

Optionally, in the perovskite quantum dot composite fine particle, a mass ratio of the perovskite quantum dot to the polymer is 0.1% to 50%.

Optionally, the mass ratio of the polymer to the solvent I is 1% to 50%.

Optionally, the mass ratio of the solvent I to the polymer is 2 to 200.

Alternatively, the mass ratio of the solvent I to the polymer is 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10.

Optionally, the polymer, the quantum dot precursor and the solvent are mixed and stirred to dissolve to obtain a solution I.

Optionally, the solution II further comprises a solvent II. The solvent II is at least one selected from tetrahydrofuran, amyl acetate, toluene and acetone.

Optionally, the mass ratio of the coating material to the organic solvent II is 1:5 to 100.

Alternatively, the mass ratio of the coating material to the organic solvent II is 1:5, 1:6, 1:7, 1:8, 1:9, 1.

Optionally, the ratio of the feed rates of the material I and the material II is: 1 to 5:1 to 10.

Optionally, the ratio of the feed rates of the material I and the material II is: <xnotran>,,,,, 1:10,,,,, 2:10,,,,, 3:10,,,,, 4:10,,,,, 5:10. </xnotran>

According to another aspect of the invention, a perovskite quantum dot composite material obtained by the preparation method is provided.

Optionally, the perovskite quantum dot composite particle comprises a cladding material and a perovskite quantum dot particle. The coating material coats the perovskite quantum dot composite particles. The coating material includes a polymer having a high water oxygen barrier rate. The perovskite quantum dot composite particle comprises a perovskite quantum dot and a polymer.

Optionally, the coating material comprises at least one of polyvinylidene chloride, ethylene vinyl alcohol copolymer, polyethylene.

Optionally, the perovskite quantum dot composite material is of a core-shell structure.

Optionally, the shell has a thickness of 0.1 μm to 100 μm.

Optionally, the particle size of the perovskite quantum dot composite fine particle is 0.1 μm to 100 μm.

Optionally, the perovskite quantum dots comprise at least one of perovskite quantum dots M and perovskite quantum dots N.

The perovskite quantum dot M is a core-shell structure of a compound a coated by a compound c.

The compound a is selected from at least one of compounds shown in a chemical formula I:

ABX ₃ formula I

Wherein A is selected from NH ₂ CHNH ₂ ⁺ 、CH ₃ NH ₃ ⁺ 、Cs ⁺ 、Rb ⁺ At least one of;

b is selected from Pb ²⁺ 、Cd ²⁺ 、Mn ²⁺ 、Zn ²⁺ 、Sn ²⁺ 、Ge ²⁺ At least one of (a);

x is at least one selected from anions of halogen elements;

the perovskite quantum dot N is a core-shell structure of a compound b coated by a compound c;

the compound b is at least one compound shown in a chemical formula II:

AB(I)B(III)X ₆ formula II

b (I) is selected from Ag ⁺ 、Na ⁺ 、Au ⁺ At least one of;

b (III) is selected from In ³⁺ 、Bi ³⁺ 、Au ³⁺ 、Sb ³⁺ 、Yb ³⁺ 、Er ³⁺ At least one of;

x is at least one selected from anions of halogen elements;

Optionally, the perovskite quantum dots have a size in at least one dimension of 2 to 50nm.

Optionally, the perovskite quantum dots have a size in at least one dimension of 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, 40nm, 41nm, 42nm, 43nm, 44nm, 45nm, 46nm, 47nm, 48nm, 49nm, or 50nm.

Optionally, the perovskite quantum dot composite particle further comprises a polymer. The polymer is at least one selected from polyvinylidene fluoride, polyvinylidene fluoride and trifluoroethylene copolymer, polyacrylonitrile, polyvinyl acetate, cellulose acetate, cyano cellulose, polysulfone, aromatic polyamide, polyimide, polycarbonate, polystyrene and polymethyl methacrylate.

Optionally, the polymer encapsulates the perovskite quantum dots.

According to still another aspect of the present application, an apparatus for preparing a perovskite quantum dot composite material is provided, and comprises an atomizer a, an atomizer b and a dryer.

The extension line of the atomizer a and the extension line of the atomizer b form an included angle: 80 to 100 degrees.

The dryer surrounds the outside of the atomizer a.

Optionally, an extension line of the atomizer a and an extension line of the atomizer b form an included angle: 80 °, 81 °, 82 °, 83 °, 84 °, 85 °, 86 °, 87 °, 88 °, 89 °, 90 °, 91 °, 92 °, 93 °, 94 °, 95 °, 96 °, 97 °, 98 °, 99 °, or 90 °.

The perovskite quantum dot composite material is at least one selected from the perovskite quantum dot composite material and the perovskite quantum dot composite material prepared by the method.

Optionally, the atomizers b comprise an atomizer b1, an atomizer b2, a … …, and an atomizer bn.

Wherein n is an integer of 1 to 4.

The atomizer b1, the atomizer b2, the atomizer … … and the atomizer bn are arranged in parallel.

Optionally, n =1, 2, 3 or 4.

Optionally, the atomizer b is located below the atomizer a, the liquid drops sprayed from the atomizer a are dried by hot air of a dryer to form the perovskite quantum dot composite particles, and the liquid drops sprayed from the atomizer b form a coating layer on the surface of the perovskite quantum dot composite particles.

Optionally, in-situ coating of the perovskite quantum dot composite material is achieved by using a spray drying device with a two-way two-fluid atomizer, and effective coating is achieved by adjusting the feed rate of the two-way atomizer.

Alternatively, the feed rate of atomizer a: 50 ml/h-50000 ml/h. The air inlet pressure: 0.02-1 MPa, air inlet speed: 15L/min to 100L/min.

Alternatively, the feed rate of atomizer b: 50 ml/h-50000 ml/h. Intake pressure of atomizer b: 0.02-1 MPa, air inlet speed: 15L/min to 100L/min.

Optionally, the inlet air temperature of the air inlet: 50-200 ℃.

Alternatively, the feed rate of the atomizer a is 1000ml/h, the inlet pressure is 0.08MPa, and the inlet velocity is 60L/min.

Alternatively, the feed rate of the atomizer b is 500ml/h, the inlet pressure is 0.05MPa, and the inlet velocity is 50L/min.

Optionally, the inlet air temperature of the air inlet is 90 ℃.

Alternatively, the preparation method is also suitable for surface coating of the inorganic quantum dot material.

Optionally, the inorganic quantum dots comprise at least one of cadmium selenide, indium phosphide, lead sulfide.

Optionally, the surface coating of the inorganic quantum dot material comprises:

(1) And atomizing and drying the dispersion liquid containing the inorganic quantum dots to obtain the inorganic quantum dots.

(2) And atomizing a solution containing a coating material, spraying the solution on the surface of the inorganic quantum dot, drying and reacting to obtain the inorganic quantum dot composite material.

According to a further aspect of the present application, there is provided a use of at least one of the perovskite quantum dot composite material as described in any one of the above, the perovskite quantum dot composite material prepared according to any one of the above methods in display devices, lighting devices, photovoltaic light conversion materials, agricultural light conversion materials, fluorescent coatings and fluorescent security inks.

Optionally, the display device comprises a Micro/Mini LED direct display, an LED lighting device and a liquid crystal display backlight.

The beneficial effect of this application is as follows:

(1) According to the method, the prepared perovskite quantum dots/polymer particles are coated in situ by using a spray drying method, so that the damage effect on quantum dot materials in the traditional liquid phase coating method is avoided; the in-situ coating method is carried out in an anhydrous and oxygen-free environment in the whole process, and does not influence the optical properties of the coated perovskite quantum dots/polymer particles.

(2) The in-situ coating method in the application has the advantages of simple process, easiness in enlarged production, avoidance of the surface compatibility problem and the fussy cleaning post-treatment link faced by ex-situ coating, capability of recycling the organic solvent used in the coating link, low production cost and environmental friendliness.

(3) The in-situ coating method is also suitable for surface coating of various traditional inorganic quantum dot materials such as cadmium selenide, indium phosphide, lead sulfide and the like, namely, the perovskite quantum dot precursor solution is replaced by the corresponding dispersion liquid of the quantum dot material.

(4) The coated perovskite quantum dot/polymer particle in the invention not only improves the water oxygen barrier property of the material, but also improves the corrosion resistance of the material, can be blended with various materials such as photoresist, UV adhesive, pressure sensitive adhesive and various organic solvents, and can prepare luminescent materials in various forms such as luminous dots, lines, films and the like by using various processes such as dispensing, ink-jet printing, screen printing, tape casting, photoetching and the like, and the luminescent materials are applied to Micro/Mini LED direct display of small-size devices, LED illuminating devices, liquid crystal display backlight and the like, thereby widening the application range of the perovskite/polymer composite material.

Drawings

FIG. 1 is a schematic diagram of a two-way spray dryer used for preparing a perovskite quantum dot composite light diffusant according to the present invention; wherein, (1) is a drying tank body; (2) a two-fluid atomizer a; (3) is a hot air inlet; (4) a two-fluid atomizer b; and (5) drying a discharge hole of the tank body.

FIG. 2 shows green CH prepared in example 1 of the present invention ₃ NH ₃ PbBr ₃ A physical diagram of the perovskite quantum dot composite material.

FIG. 3 shows green CH prepared in example 1 of the present invention ₃ NH ₃ PbBr ₃ And (3) a fluorescence spectrogram of the perovskite quantum dot composite material under the excitation of blue light.

FIG. 4 shows green CH prepared in example 1 of the present invention ₃ NH ₃ PbBr ₃ Scanning electron microscopy images of perovskite quantum dot composites.

FIG. 5 shows green CH prepared in example 1 of the present invention ₃ NH ₃ PbBr ₃ Scanning electron microscopy of the perovskite quantum dot composite cross section.

FIG. 6 is a schematic structural diagram of a quantum dot light-converting film in example 1 of the present invention; the coated or uncoated quantum dot is positioned between the two layers of PET films; wherein, 1 is a PET film; 2 is a green quantum dot (coated or uncoated); and 3 is UV glue.

Fig. 7 is a graph showing the effect of luminance decay versus aging time of a light conversion film prepared based on coated and uncoated green quantum dots in example 1 of the present invention.

FIG. 8 shows red (Cs) prepared in example 2 of the present invention _0.5 Rb _0.5 )PbI ₃ Fluorescence spectrum of the perovskite quantum dot composite material under the excitation of blue light.

FIG. 9 shows red (Cs) prepared in example 2 of the present invention _0.5 Rb _0.5 )PbI ₃ Particle size distribution curve of perovskite quantum dot composite material.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In addition, the terms "comprising," "including," "containing," and "having" are intended to be non-limiting, i.e., that other steps and other ingredients can be added that do not affect the results. Materials, equipment and reagents are commercially available unless otherwise specified.

In order to make the objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

The invention provides a preparation method of a perovskite quantum dot composite material, which utilizes a classic spray drying technology and carries out in-situ coating in the preparation process of perovskite quantum dot composite micro powder so as to form a protective shell layer of 0.1-100 microns on the surface of the perovskite quantum dot composite micro powder. The preparation process is shown in figure 1, the blending solution (solution a) of perovskite quantum dot precursor and polymer is formed into fan-shaped atomized micro-droplets by a two-fluid atomizer (2) through a liquid conveying pipeline, the fan-shaped atomized micro-droplets enter a drying tower (1), and the fan-shaped atomized micro-droplets are dried by hot air blown in from an air inlet (3) to preferentially form perovskite/polymer micro-powder. The coating material solution (solution b) synchronously enters a drying tank through a fan-shaped atomized micro-liquid drop formed by a two-fluid atomizer (4) positioned above the side of the drying tower through a liquid conveying pipeline, and the atomized micro-liquid forms a coating layer on the surface of the perovskite/polymer micro-powder. More two-fluid atomizers can be added above the side of the drying tower to improve the coating effect.

The solution a and the solution b are pumped by a feed pump arranged in the liquid conveying pipeline and input into a two-fluid atomizer, and the liquid conveying speeds of different solutions are independently controlled. The size of the micro-droplets generated by the two-fluid atomizer is controlled by the aperture (aperture 0.2-5 mm) of the nozzle of the atomizer, the infusion flow rate, the air inlet flow rate and the air inlet pressure, and the size of the perovskite/polymer micro-powder is controlled by the size of the micro-droplets generated by spraying and the concentration of the solution.

Example 1 Green CH ₃ NH ₃ PbBr ₃ (MAPbBr ₃ ) In-situ coating preparation of perovskite quantum dot composite material

Will CH ₃ NH ₃ Br(MABr)、PbBr ₂ Octylamine bromide in a molar ratio of 1:1.05:0.5 was dissolved in 200ml of anhydrous N, N Dimethylformamide (DMF), and 10g of polymethyl methacrylate Polymer (PMMA) was added to form solution I. Ensure that (MABr + PbBr) ₂ + octylamine bromide) to the charged polymer at a mass ratio of 1. Polyvinylidene chloride (PVDC) is dissolved in Tetrahydrofuran (THF) solvent to form a solution II, and the mass ratio of the PVDC to the THF is ensured to be 2. The two solutions were stirred for 2 hours, and then spray-dried, and a schematic diagram of a dryer in a two-way spray-drying apparatus used therein is shown in FIG. 1. The feeding speed of the solution I is 1000ml/h, the air inlet pressure is 0.08MPa, the air inlet speed is 60L/min, the feeding speed of the solution II is 500ml/h, the air inlet pressure is 0.05MPa, and the air inlet speed is 50L/min. The air inlet temperature of the dryer is 90 ℃.

The obtained green perovskite/polymer powder was uniformly dispersed and showed a bright green color as shown in FIG. 2. The emission spectrum is shown in FIG. 3, the emission peak is located at 536nm, the half-peak width is 23nm, and the fluorescence quantum yield of the polymer powder is over 90 percent. From its optical properties, it can be concluded that MAPbBr was present in the powder ₃ The size of the perovskite quantum dots is about 5nm. A scanning electron micrograph of the powder is shown in figure 4, from which it is clear that the particles are about 5 μm in size, the surface of the particles has been coated with a thin polymer film, and the surface has been substantially completely coated. It can be seen from fig. 5 that the thickness of the shell layer coated on the surface of the composite fine particle is between 0.2 and 0.3 μm, and continuous coating of the surface is achieved.

The method comprises the steps of adding green quantum dot powder (uncoated) obtained by direct spray drying without in-situ coating and green quantum dot powder (coated) obtained by in-situ coating into UV curing adhesive according to the mass ratio of 1.

The film prepared based on the uncoated and coated green powder is placed in an environmental test chamber with 60 ℃ and 90% relative humidity for an aging experiment, the brightness attenuation situation of the film is shown in figure 7 after the film is aged for 550 hours, the brightness of the light conversion film prepared based on the green micro powder prepared by the in-situ coating process is hardly attenuated after the film is aged for 550 hours, and the perovskite/polymer particles are proved to be remarkably improved after the surface of the film is coated with a film layer with excellent water sample barrier property in situ.

Example 2 Red (Cs) _0.5 Rb _0.5 )PbI ₃ In-situ coating preparation of perovskite quantum dot composite material

Mixing RbI, csI and PbI ₂ And octylamine bromide in a molar ratio of 0.5:0.5: 1.5 in 200ml of anhydrous N, N Dimethylformamide (DMF), and 10g of polymethyl methacrylate Polymer (PMMA) was added to form solution I. Ensure that (RbI + CsI + PbI) ₂ + octylamine bromide) to the charged polymer at a mass ratio of 1. Polyvinylidene chloride (PVDC) is dissolved in Tetrahydrofuran (THF) solvent to form a solution II, and the mass ratio of the PVDC to the THF is ensured to be 2. The two solutions were stirred for 2 hours, and then spray-dried, and a schematic diagram of a dryer in a two-way spray-drying apparatus used therein is shown in FIG. 1. The feeding speed of the solution I is 1000ml/h, the air inlet pressure is 0.08MPa, the air inlet speed is 60L/min, the feeding speed of the solution II is 500ml/h, the air inlet pressure is 0.05MPa, and the air inlet speed is 50L/min. The air inlet temperature of the dryer is 90 ℃.

The resultant Red color (Cs) _0.5 Rb _0.5 )PbI ₃ The luminescence spectrum of the perovskite/polymer powder is shown in FIG. 8, the luminescence peak is located at 627nm, the half-peak width is 39nm, and the fluorescence quantum yield of the polymer powder exceeds 70%. From its optical properties, it can be concluded that (Cs) is present in the powder _0.5 Rb _0.5 )PbI ₃ The size of the perovskite quantum dots is about 4nm. From red (Cs) in FIG. 9 _0.5 Rb _0.5 )PbI ₃ The particle size distribution of the perovskite/polymer powder can be seen to be very uniform, consistent with the results of scanning electron microscopy, with a powder size of between 2 and 10 μm. The in-situ coating process selected was the same as in example 1, and therefore the thickness of the coated shell was judged to be the same.

Example 3 yellow Cs ₂ AgIn _0.8 Bi _0.2 Cl ₆ In-situ coating preparation of perovskite quantum dot composite material

Adding CsCl, agCl and InCl ₃ 、BiCl ₃ And octylamine bromide in a molar ratio of 2:1:0.8:0.2: dissolving in dimethyl sulfoxide (DMSO) 10ml in a ratio of 0.8 to form a perovskite precursor solution; 190ml of anhydrous N, N Dimethylformamide (DMF) was added with 10g of polymethyl methacrylate Polymer (PMMA) to form a polymer solution, and then the prepared perovskite precursor solution was added to form a solution I. Ensuring that (CsCl + AgCl + InCl) ₃ +BiCl ₃ + octylamine bromide) to the charged polymer at a mass ratio of 1. Polyvinylidene chloride (PVDC) was dissolved in Tetrahydrofuran (THF) solvent to form solution ii, wherein the mass ratio of PVDC to THF was 2. The two solutions were stirred for 2 hours, and then spray-dried, and a schematic diagram of a dryer in a two-way spray-drying apparatus used therein is shown in FIG. 1. The feeding speed of the solution I is 1000ml/h, the air inlet pressure is 0.08MPa, the air inlet speed is 60L/min, the feeding speed of the solution II is 500ml/h, the air inlet pressure is 0.05MPa, and the air inlet speed is 50L/min. The air inlet temperature of the dryer is 90 ℃. Finally obtaining yellow Cs ₂ AgIn _0.8 Bi _0.2 Cl ₆ Perovskite quantum dot composite material. In the present example, only the material of the perovskite precursor was modified, thereby changing the optical properties of the polymer powderCan not affect the appearance of the polymer composite powder and the coating shell layer.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A preparation method of a perovskite quantum dot composite material is characterized by comprising the steps of atomizing a solution II containing a coating material, spraying the solution II on the surface of perovskite quantum dot composite particles, drying, reacting, and forming a coating layer on the surface of the perovskite quantum dot composite particles to obtain the perovskite quantum dot composite material.

2. The method of claim 1, comprising:

(1) Atomizing and drying a solution I containing a perovskite quantum dot precursor and a polymer to obtain perovskite quantum dot composite particles;

(2) Atomizing a solution II containing a coating material, spraying the solution II on the surface of the perovskite quantum dot composite particle, drying and reacting to form a coating layer on the surface of the perovskite quantum dot composite particle to obtain the perovskite quantum dot composite material;

preferably, the solution I containing the perovskite quantum dot precursor and the polymer is atomized and then dried by hot air at 50-200 ℃ to obtain perovskite quantum dot composite particles;

preferably, the perovskite quantum dot precursor comprises a first precursor, a second precursor and a compound c;

the chemical formula of the first precursor is shown as formula III:

AX formula III;

wherein A is selected from NH ₂ CHNH ₂ ⁺ 、CH ₃ NH ₃ ⁺ 、Cs ⁺ 、Rb ⁺ 、Ag ⁺ At least one of (a);

x is at least one selected from anions of halogen elements;

the chemical formula of the second precursor is shown as formula V:

BX _t formula V;

wherein B is selected from Pb ²⁺ 、Cd ²⁺ 、Mn ²⁺ 、Zn ²⁺ 、Sn ²⁺ 、Ge ²⁺ 、Bi ³⁺ 、In ³⁺ At least one of;

t＝2～3；

the compound c is selected from at least one of oleic acid, oleylamine, oleic acid bromine and Xin An bromine;

preferably, the polymer is selected from at least one of polyvinylidene fluoride, polyvinylidene fluoride and trifluoroethylene copolymer, polyacrylonitrile, polyvinyl acetate, cellulose acetate, cyano cellulose, polysulfone, aromatic polyamide, polyimide, polycarbonate, polystyrene, and polymethyl methacrylate.

3. The method according to claim 2, wherein the solution I further comprises a solvent I; the solvent I is an organic solvent;

preferably, the organic solvent is selected from at least one of N, N-dimethyl amide, dimethyl sulfoxide, N-hexane, octadecene, trimethyl phosphate, triethyl phosphate, N-methyl pyrrolidone and dimethyl acetamide;

preferably, in the perovskite quantum dot composite fine particle, the mass ratio of the perovskite quantum dot to the polymer is 0.1% to 50%;

preferably, the mass ratio of the solvent I to the polymer is 2 to 200;

preferably, the solution II also comprises a solvent II; the solvent II is at least one selected from tetrahydrofuran, amyl acetate, toluene and acetone;

preferably, the mass ratio of the coating material to the organic solvent II is 1:5 to 100;

preferably, the ratio of the feed rates of solution I to solution II is: 1 to 5:1 to 10.

4. The perovskite quantum dot composite material obtained by the production method according to any one of claims 1 to 3.

5. The perovskite quantum dot composite of claim 4,

the perovskite quantum dot composite material comprises a coating material and perovskite quantum dot composite particles;

the coating material coats the perovskite quantum dot composite particles;

the coating material comprises a polymer with high water oxygen barrier rate;

the perovskite quantum dot composite particle comprises a perovskite quantum dot and a polymer.

6. The perovskite quantum dot composite of claim 5,

the coating material comprises at least one of polyvinylidene chloride, ethylene-vinyl alcohol copolymer and polyethylene;

preferably, the coating material is polyvinylidene chloride.

7. The perovskite quantum dot composite of claim 5, wherein the perovskite quantum dot composite is a core-shell structure;

preferably, the thickness of the shell is 0.1 to 100 μm;

preferably, the particle size of the perovskite quantum dot composite fine particle is 0.1 to 100 μm;

preferably, the perovskite quantum dots have a size of 2 to 50nm in at least one dimension.

8. The device for preparing the perovskite quantum dot composite material is characterized by comprising an atomizer a, an atomizer b and a dryer;

the extension line of the atomizer a and the extension line of the atomizer b form an included angle: 80-100 degrees;

the dryer is surrounded on the outer side of the atomizer a;

the perovskite quantum dot composite material is at least one selected from the perovskite quantum dot composite material prepared by the method according to any one of claims 1 to 3 and the perovskite quantum dot composite material according to any one of claims 4 to 7.

9. The apparatus of claim 8, wherein the atomizers b comprise atomizers b1, atomizers b2, … …, atomizers bn;

wherein n is an integer of 1 to 4;

the atomizer b1, the atomizer b2 and the atomizer bn are arranged in parallel;

preferably, the atomizer b is positioned below the atomizer a, the liquid drops sprayed by the atomizer a are dried by hot air of a dryer to form the perovskite quantum dot composite particles, and the liquid drops sprayed by the atomizer b form a coating layer on the surfaces of the perovskite quantum dot composite particles;

preferably, the feed rate of atomizer a: 50 ml/h-50000 ml/h; the air inlet pressure: 0.02-1 MPa, air inlet speed: 15L/min to 100L/min;

preferably, the feed rate of atomizer b: 50 ml/h-50000 ml/h; intake pressure of atomizer b: 0.02-1 MPa, air inlet speed: 15L/min to 100L/min;

preferably, the feeding speed of the atomizer a is 1000ml/h, the air inlet pressure is 0.08MPa, and the air inlet speed is 60L/min;

preferably, the feeding speed of the atomizer b is 500ml/h, the air inlet pressure is 0.05MPa, and the air inlet speed is 50L/min;

preferably, the inlet air temperature of the air inlet is 90 ℃.

10. The perovskite quantum dot composite material prepared by the method according to any one of claims 1 to 3 and the perovskite quantum dot composite material according to any one of claims 4 to 7 are applied to display devices, lighting devices, photovoltaic light conversion materials, agricultural light conversion materials, fluorescent coatings and fluorescent anti-counterfeiting inks.