WO2024021759A1

WO2024021759A1 - Quantum dot light-emitting thin film, preparation thereof and use thereof in white-light mini-led device

Info

Publication number: WO2024021759A1
Application number: PCT/CN2023/093169
Authority: WO
Inventors: 宣曈曈; 解荣军
Original assignee: 厦门大学
Priority date: 2022-07-29
Filing date: 2023-05-10
Publication date: 2024-02-01
Also published as: CN115247060A; CN115247060B

Abstract

A quantum dot light-emitting thin film, the preparation thereof and the use thereof in a white-light Mini LED device. The quantum dot light-emitting thin film is made of a quantum dot light-emitting material. The quantum dot light-emitting material is prepared by embedding quantum dots into pore channels in the surfaces of mesoporous nanospheres, then wrapping the surfaces with transparent oxide shell layers, and finally embedding the spheres into an organic polymer; and the general chemical formula thereof is: M@N/P@Q, wherein M is quantum dots; @ represents embedding; N is mesoporous nanospheres; / represents core-shell; P is a transparent oxide shell layer; and Q is an organic polymer. The quantum dot light-emitting thin film has high light-emitting stability and brightness and low preparation cost.

Description

A quantum dot luminescent material, quantum dot luminescent film, preparation and application in white light Mini-LED devices

Cross-references to related applications

This application claims priority to the Chinese patent application 202210907164.7 titled "Quantum dot luminescent film, preparation and application in white light Mini-LED devices" submitted on July 29, 2022. The entire content of the application Incorporated herein by reference.

Technical field

The invention relates to a quantum dot luminescent material, a quantum dot luminescent film, their preparation and their application in white light Mini-LED devices, and belongs to the field of quantum dot luminescence technology.

Background technique

Quantum dots (QDs) have the advantages of high fluorescence quantum efficiency, strong luminescence tunability, narrow fluorescence half-peak width, high color purity, small size, and good stability. Therefore, they are widely used in lighting, display, biomedicine, Photovoltaics, photoelectric detection, optical communications and other fields. In recent years, with the continuous growth of the amount of information, the information people obtain from displays is no longer limited to text or pictures, but more often pictures and videos with more colorful colors. However, the backlight display using white LED prepared by "blue LED + rare earth doped phosphor" as a backlight source combined with a liquid crystal display has a bottleneck problem of a relatively small color display range. In response to this problem, researchers proposed to use quantum dot luminescent materials with narrow emission and high color purity to replace rare earth doped phosphors (hereinafter referred to as: phosphors) to prepare backlight sources. The color gamut range of the corresponding display has changed from the original 75% National Television System Committee (NTSC) increased to 110% NTSC (Zhong Haizheng et al., Quantum dot liquid crystal display backlight technology, China Optics, 2017, 10(5), 666-680). In addition, with the rapid development of fifth-generation mobile communication technology (5G), information transmission and display not only have higher requirements for color display, but also require ultra-high resolution, high brightness, ultra-high contrast and low cost. To this end, a backlight display technology based on "blue Mini-LED + red and green quantum dot film" was derived, which uses white Mini-LED to replace the traditional white LED as the backlight source, and achieves ultra-high brightness and ultra-wide through regional control. Color gamut, ultra-high resolution, and ultra-high contrast display.

Although quantum dots have certain advantages in luminescence stability compared with organic dyes, during long-term operation of Mini-LED devices, they will be affected by multiple factors such as high-power density blue light, heat, water, and oxygen, and their luminescence will be affected. Performance degrades drastically. At the same time, quantum dots have self-absorption problems, resulting in their low external quantum efficiency, brightness saturation and low brightness in device applications.

In the prior art, there are some reports on improving the luminous performance through a water and oxygen barrier layer. However, the water and oxygen barrier layer is expensive, resulting in high cost. Therefore, there is an urgent need to develop a low-cost technology for preparing quantum dot films with high efficiency, high brightness and ultra-strong luminescence stability.

Contents of the invention

The invention provides a quantum dot luminescent material, a quantum dot luminescent film, their preparation and their application in white light Mini-LED devices, which can effectively solve the above problem of insufficient luminescence stability of quantum dots.

The present invention is implemented as follows:

The first aspect of this application provides a quantum dot luminescent film. The quantum dot luminescent film is made of quantum dot luminescent material. The quantum dot luminescent material is made by embedding quantum dots into the pores on the surface of nano mesoporous spheres, and then wrapping the surface with transparent The oxide shell is finally formed by being embedded in an organic polymer; its general chemical formula is: M@N/P@Q; where M is a quantum dot; @ means embedded; N is a nanometer mesoporous sphere; / means core shell; P is a transparent oxide shell; Q is an organic polymer.

In some embodiments, the quantum dots are ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, InP/ZnSe/ZnS, InP/GaP/ZnS, ABX ₃ , At least one _of A ₂ B One kind, B is at least one of Pb, Sn, and Mn, and X is at least one of Cl, Br, and I; the particle size is 3 to 20 nm.

In some embodiments, the nano mesoporous spheres are at least one of mesoporous silica, mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconia; the particle size is 50 to 500 nm, and the mesopore size is 5 to 15 nm.

In some embodiments, the oxide in the transparent oxide shell is at least one of silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, and nickel oxide.

In some embodiments, the organic polymer is at least one of polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, polyvinylidene fluoride, and polyethyleneimine.

In some embodiments, the quantum dot luminescent film meets at least one of the following conditions:

1) The mass percentage of quantum dots M and nano-mesoporous spheres N is 1 to 30wt%, optionally 10 to 20wt%;

2) The mass percentage of nanospheres M@N/P and organic polymer film Q is 1 to 25wt%, optionally 10 to 20wt%;

3) The thickness of the P layer is 5~100nm, optionally 10~50nm.

The second aspect of the present application provides a method for preparing the above-mentioned quantum dot luminescent film, which includes the following steps:

S1, embed quantum dots M into the surface pores of nano-mesoporous spheres N through physical adsorption to form M@N composite nanospheres;

S2, disperse the M@N composite nanospheres into a non-polar solvent, add the transparent oxide shell P precursor, water, catalyst and ethanol, and use the hydrolysis reaction to wrap the P layer on the M@N surface to close the mesoporous channels. Form M@N/P nanosphere solution;

S3, dissolve the organic polymer Q to form a uniform sol, add the M@N/P nanoparticle solution into the above sol, and stir thoroughly to form a uniform mixed sol. After extrusion and solidification, the M@N/P nanoparticles Embedded organic polymer Q, The final product M@N/P@Q quantum dot luminescent film was obtained.

In some embodiments, the mass percentage of quantum dots M and nano-mesoporous spheres N is 1 to 30 wt%, optionally 10 to 20 wt%.

In some embodiments, the mass percentage of nanospheres M@N/P and organic polymer film Q is 1 to 25 wt%, optionally 2 to 15 wt%.

In some embodiments, the thickness of the P layer ranges from 5 to 100 nm, optionally from 10 to 50 nm.

The third aspect of the present application provides a white light Mini-LED device, including a quantum dot luminescent film.

The fourth aspect of the present application provides a quantum dot luminescent material. The quantum dot luminescent material includes quantum dots, nano-mesoporous spheres, a transparent oxide shell and an organic polymer, wherein the quantum dots are embedded in the surface of the nano-mesoporous spheres. M@N composite nanospheres are formed in the pores, and the transparent oxide shell is coated on the surface of the M@N composite nanospheres to form a core-shell structure. The core-shell structure is dispersed in the organic polymer.

In some embodiments, the general chemical formula of the quantum dot luminescent material is: M@N/P@Q; where M is a quantum dot; @ represents embedding; N represents nano mesoporous spheres; / represents core shell; P represents transparent oxidation material shell; Q is an organic polymer.

In some embodiments, the quantum dots include ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, InP/ZnSe/ZnS, InP/GaP/ZnS, ABX ₃ , at least one selected from the group consisting of A ₂ _B , at least one selected from the group consisting of ethylenediamine and amphetamine, B includes at least one selected from the group consisting of Pb, Sn, and Mn, and X includes at least one selected from the group consisting of Cl, Br, and I. of at least one.

In some embodiments, the particle size of the quantum dots is 3-20 nm.

In some embodiments, the nano-mesoporous spheres include at least one selected from the group consisting of mesoporous silica, mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconia.

In some embodiments, the particle size of the nano mesoporous spheres is 50-500 nm.

In some embodiments, the mesopore size of the nano mesoporous spheres is 5 to 15 nm.

In some embodiments, the oxide in the transparent oxide shell includes at least one selected from the group consisting of silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, and nickel oxide. .

In some embodiments, the organic polymer includes at least one selected from the group consisting of polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, polyvinylidene fluoride, and polyethyleneimine. A sort of.

In some embodiments, the quantum dot luminescent material satisfies at least one of the following conditions:

1) The mass percentage of quantum dots relative to nano-mesoporous spheres is 1-30wt%, optionally 10-20wt%;

2) The mass percentage of the core-shell structure relative to the organic polymer is 1 to 25 wt%, optionally 2 to 15 wt%;

3) The thickness of the transparent oxide shell is 5~100nm, optionally 10~50nm.

The beneficial effects of the present invention are:

Compared with the existing quantum dot luminescent film preparation technology, the present invention does not require the use of expensive water and oxygen barrier films, can maintain the excellent luminescence and super luminescence stability of the quantum dots, and is low in cost.

Compared with existing quantum dot luminescent films, the quantum dot luminescent film provided by the present invention has stronger luminescence stability. After long-term exposure to dual 85 and high-power-density blue Mini-LED, the luminescent performance of the quantum dot luminescent film of the present invention has almost no attenuation.

(3) The white Mini-LED prepared by combining the quantum dot luminescent film of the present invention with the blue Mini-LED array not only has an ultra-wide color gamut and reliability, but also exhibits ultra-high brightness.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of the quantum dot luminescent film of the present invention;

Figure 2 is an electroluminescence spectrum chart of the white Mini-LED array provided in Embodiment 12 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Accordingly, the following detailed description of embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

The first embodiment of the present application provides a quantum dot luminescent film. The quantum dot luminescent film emits light from quantum dots. The quantum dot luminescent material is formed by embedding quantum dots into the pores on the surface of nano mesoporous spheres, then wrapping the surface with a transparent oxide shell, and finally embedding it in an organic polymer; its general chemical formula is: M@N /P@Q; where M is a quantum dot; @ represents embedding; N is a nanometer mesoporous sphere; / represents a core shell; P is a transparent oxide shell; Q is an organic polymer.

In the quantum dot luminescent film of the present application, the main functions of the nano mesoporous spheres are (i) as a framework material, using the spatial confinement effect to inhibit the agglomeration of quantum dots, thereby reducing the generation of surface defects and self-absorption effects; (ii) through The mesopore size and structural micromorphology of the nano mesoporous spheres enable local light field control and improve photon extraction efficiency; the main function of the transparent oxide shell is (i) to isolate water and oxygen to avoid their impact on the luminescence performance of the internal quantum dots ; (ii) By changing the thickness, refractive index, dielectric constant, etc. of the transparent oxide, the light field intensity distribution can be flexibly improved and the photon extraction efficiency can be improved; the main functions of organic polymers are (i) used as framework materials for film formation and ( ii) Improve the blue light absorption rate of the quantum dot film by changing its refractive index, dielectric constant and thickness -.

In some embodiments, the quantum dots are ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, InP/ZnSe/ZnS, InP/GaP/ZnS, ABX ₃ , At least one _of A ₂ B One kind, B is at least one of Pb, Sn, and Mn, X is at least one of Cl, Br, and I; the particle size is 3 to 20 nm.

When the particle size of quantum dots is 3 to 20nm, it has the advantages of strong quantum size effect, few surface defects, high fluorescence quantum efficiency, and good stability; when its particle size is less than 3nm, the emission wavelength is generally in the blue-violet region, and surface defects More particles lead to low fluorescence quantum efficiency; when the particle size is greater than 20nm, the quantum size effect is weakened, resulting in lower fluorescence quantum efficiency, which also cannot meet the needs of display applications.

The above particle size is 50-500nm, which can achieve localized light field control, improve photon extraction efficiency, and effectively improve the luminous efficiency of quantum dot microspheres; when the above particle size is less than 50nm, the number of mesopores on the surface of the nano mesoporous sphere is small, which is harmful to The loading efficiency of quantum dots is low; the above-mentioned particle size is larger than 500nm, which is prone to sedimentation during the film preparation process, making it difficult to significantly improve the uniform luminescence of the quantum dot film. The size of the above-mentioned mesopores is 5 to 15nm, which can make full use of the spatial confinement effect to inhibit the agglomeration of quantum dots and avoid reabsorption between quantum dots; when the size of the above-mentioned mesopores is less than 5nm, the quantum dots will be blocked when entering the mesopores. Larger, the utilization efficiency of mesopores is low; when the mesopore size is larger than 15nm, when too many quantum dots are gathered, the quantum dots are prone to agglomeration and reabsorption in the mesopores, resulting in their fluorescence quenching.

In some embodiments, the oxide in the transparent oxide shell is at least one of silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, and nickel oxide. They have super chemical stability, high light transmittance, high refractive index, etc. They can not only effectively isolate the erosion of quantum dots by water and oxygen, but also change the local light field intensity and improve the blue light absorption rate and Luminous efficiency.

In some embodiments, the organic polymer is at least one of polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, polyvinylidene fluoride, and polyethyleneimine. Since M@N/P has excellent luminescence stability, there are no special requirements for the water and oxygen barrier properties and thermal conductivity of the organic polymer. The above organic polymers not only have high Light transmittance, adjustable refractive index, good solubility, and low price greatly reduce the cost of the final product.

In some embodiments, the above-mentioned quantum dot luminescent film satisfies at least one of the following conditions:

1) The mass percentage of quantum dots M and nano-mesoporous spheres N is 1 to 30 wt%, optionally 10 to 20 wt%. It can avoid excessive dosage of quantum dots causing aggregation and triggering fluorescence quenching after aggregation.

2) The mass percentage of nanospheres M@N/P and organic polymer film Q is 1 to 25 wt%, optionally 2 to 15 wt%, to optimize the film-forming performance of the quantum dot luminescent film.

3) The thickness of the P layer is 5~100nm, optionally 10~50nm. It can balance the luminescence performance and stability of quantum dots to avoid a decrease in luminescence performance caused by excessive thickness, and insufficient improvement in stability due to excessive thickness.

4) The thickness of the quantum dot luminescent film is 100 to 500 μm. When the film thickness is less than 100 μm, the quantum dots’ absorption of blue light is insufficient, causing blue light leakage and affecting display performance; when the film thickness is greater than 500 μm, it prevents the emitted light of the quantum dots from being trapped in the film, affecting the luminous efficiency of the film.

The second embodiment of the present application provides a method for preparing the above-mentioned quantum dot luminescent film, which includes the following steps:

S2, disperse the M@N composite nanospheres into a non-polar solvent, add the transparent oxide shell P precursor, water, catalyst and ethanol, and use the hydrolysis reaction to wrap the P layer on the M@N surface to close the mesoporous channels. To isolate the damage of quantum dots by water vapor and oxygen, the M@N/P nanosphere solution is formed;

S3, dissolve the organic polymer Q to form a uniform sol, add the M@N/P nanoparticle solution into the above sol, and stir thoroughly to form a uniform mixed sol. After extrusion and solidification, the M@N/P nanoparticles Embedding organic polymer Q, the final product M@N/P@Q quantum dot luminescent film is obtained.

This method does not require the use of expensive water and oxygen barrier films, and the preparation cost is low. The prepared quantum dot luminescent film not only maintains excellent luminescent properties, but also shows superior luminescence stability under double 85 (85°C and 85% humidity environment) and high power density blue light.

In some embodiments, the mass percentage of quantum dots M and nano-mesoporous spheres N is 1 to 30 wt%, optionally 10 to 20 wt%. Optimizing the ratio of M to N can avoid quantum dot aggregation and fluorescence quenching after agglomeration. More preferably, they are 1 wt%, 2 wt%, 3 wt%, 5 wt%, 7 wt%, 10 wt%, 15 wt%, 20 wt%, and 30 wt%.

In some embodiments, the mass percentage of nanospheres M@N/P and organic polymer film Q is 1 to 25 wt%, optionally 2 to 15 wt%. Further preference is given to 1 wt%, 2 wt%, 3 wt%, 5 wt%, 7 wt%, 10 wt%, 15 wt%, and 25 wt%. Optimize the film-forming properties of quantum dot luminescent films.

In some embodiments, the thickness of the P layer ranges from 5 to 100 nm, optionally from 10 to 50 nm. Optimize the thickness of the P layer, which can be flat Measure the luminescence performance and stability of sub-dots to avoid a decrease in luminescence performance caused by excessive thickness, and insufficient improvement in stability due to excessive thickness.

The precursor of the transparent oxide shell layer P can be tetraethyl orthosilicate, 3-aminopropyltriethoxysilane, aluminum sec-butoxide, aluminum chloride, sodium metaaluminate, and zinc acetate corresponding to each oxide. , at least one of butyl titanate, zirconium acetate, cerium acetate, nickel acetate, magnesium nitrate, etc.

In some embodiments, the non-polar solvent is at least one of toluene, chloroform, cyclohexane, and n-hexane. The above-mentioned non-polar solvent is selected to achieve sufficient and uniform dispersion of the quantum dots and protect the surface ligands of the quantum dots, thereby improving the luminescent performance of the quantum dots in the formed product.

In some embodiments, the catalyst is at least one of ammonia water, hydrochloric acid, sodium hydroxide solution, and nitric acid. Their OH ^- or H ⁺ ions are used to affect the hydrolysis rate of the transparent oxide shell P precursor in the reaction system, thereby increasing the reaction rate of the oxide.

In some embodiments, the extrusion method is blade coating or roll-to-roll.

The curing method in the above step S3 can be thermal curing or light curing according to the properties of the organic polymer used. In some embodiments, the curing method is heating or ultraviolet radiation. Among them, polymethyl methacrylate and polyvinyl alcohol are cured by heating, while polyethylene terephthalate, polyvinylidene fluoride and polyethyleneimine are cured by ultraviolet radiation. The curing efficiency is high and it is not harmful to quantum dots. The impact is smaller.

In some embodiments, the heating temperature is 40-150°C; the heating time is 1-30 minutes. The heating temperature is more preferably 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C. The heating time is further optimized to 1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes or 30 minutes.

In some embodiments, the ultraviolet light wavelength of the ultraviolet radiation is 300 to 400 nm; the optical power density is 10 to 500 mW/cm ² ; and the radiation time is 1 to 60 seconds. The optical power density is further preferably 10mW/cm ² , 50mW/cm ² , 100mW/cm ² , 200mW/cm ² , 300mW/cm ² or 500mW/cm ² . The irradiation time is further preferably 1 second, 2 seconds, 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds or 60 seconds.

The third embodiment of the present application also provides a white light Mini-LED device, including the above-mentioned quantum dot luminescent film.

In some embodiments, the white Mini-LED device is the above-mentioned quantum dot luminescent film covered on the blue Mini-LED array, and closely combined to prepare a white Mini-LED array. The quantum dot luminescent film emits bright green light and red light at the same time when excited by the blue Mini-LED, thus compounding into white light. Blue Mini-LED is an LED chip with a size of (50~200μm)×(50~200μm).

In some embodiments, the luminescence peak of the blue Mini-LED is in the range of 450 to 475 nm; the size of a single Mini-LED is in the range of 50 to 200 μm, the half-peak width is less than 20 nm, and the distance between single Mini-LEDs is within the range of 50 to 200 μm. 100～500μm.

In some embodiments, the emission peak position of green light is in the range of 525-540nm, with the preferred peak position being 535nm; red light The emission peak position is in the range of 620-640nm, with the preferred peak position being 630nm; the half-peak width is less than 38nm.

In some embodiments, the thickness of the quantum dot luminescent film is 100-500 μm, preferably 200 μm. When the film thickness is less than 100 μm, the quantum dots’ absorption of blue light is insufficient, causing blue light leakage and affecting display performance; when the film thickness is greater than 500 μm, it prevents the emitted light of the quantum dots from being trapped in the film, affecting the luminous efficiency of the film.

The fourth embodiment of the present application provides a quantum dot luminescent material. The quantum dot luminescent material includes quantum dots, nano-mesoporous spheres, a transparent oxide shell and an organic polymer, wherein the quantum dots are embedded in the nano-mesoporous spheres. M@N composite nanospheres are formed in the surface pores, and the transparent oxide shell is coated on the surface of the M@N composite nanospheres to form a core-shell structure. The core-shell structure is dispersed in the organic polymer.

In the quantum dot luminescent material of the present application, the main functions of the nano mesoporous spheres are (i) as a framework material, using the spatial confinement effect to inhibit the agglomeration of quantum dots and quantum dots, thereby reducing the generation of surface defects and self-absorption effects; (ii) through The mesopore size and structural micromorphology of the nano mesoporous spheres enable local light field control and improve photon extraction efficiency; the main function of the transparent oxide shell is (i) to isolate water and oxygen to avoid their impact on the luminescence performance of the internal quantum dots ; (ii) By changing the thickness, refractive index, dielectric constant, etc. of the transparent oxide, the light field intensity distribution can be flexibly improved and the photon extraction efficiency can be improved; the main functions of organic polymers are (i) used as framework materials for film formation and ( ii) Improve the blue light absorption rate of the quantum dot film by changing its refractive index, dielectric constant and thickness.

In some embodiments, the general chemical formula of the quantum dot luminescent material is: M@N/P@Q; where M is a quantum dot; @ represents embedded; N represents nano-mesoporous spheres; / represents core-shell; P represents transparent Oxide shell; Q is organic polymer.

The quantum dot luminescent material of the present application is suitable for coating or coating of conventional various types of quantum dots, group II/VI quantum dots, group III/V quantum dots, group I/III/V quantum dots, and group IV/VI quantum dots. Uncoated quantum dots. In some embodiments, the quantum dots include ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, InP/ZnSe/ZnS, InP/ At least one selected from the group consisting of GaP/ZnS, ABX ₃ , and A ₂ BX ₄ quantum dots; wherein A includes Cs, Rb, methylamine, formamidine, hexylamine, octylamine, dodecylamine, benzene At least one selected from the group consisting of ethylamine, benzylamine, ethylenediamine, and amphetamine. B includes at least one selected from the group consisting of Pb, Sn, and Mn. X includes Cl, Br, and I. At least one of the selected groups.

In some embodiments, the particle size of the quantum dots is 3-20 nm. When the particle size of quantum dots is 3 to 20nm, it has the advantages of strong quantum size effect, few surface defects, high fluorescence quantum efficiency, and good stability; when its particle size is less than 3nm, the emission wavelength is generally in the blue-violet region, and surface defects More particles lead to low fluorescence quantum efficiency; when the particle size is greater than 20nm, the quantum size effect is weakened, resulting in lower fluorescence quantum efficiency.

In some embodiments, the nano-mesoporous spheres include at least one selected from the group consisting of mesoporous silica, mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconia; and/or the nano-mesoporous spheres The particle size is 50 to 500 nm; and/or the mesopore size of the nano mesoporous spheres is 5 to 15 nm. The above-mentioned particle size is 50-500nm, which can realize local light field control, improve photon extraction efficiency, and effectively improve the luminous efficiency of quantum dot microspheres. When the above particle size is less than 50nm, the number of mesopores on the surface of the nano mesoporous sphere is small, and the loading efficiency of quantum dots is low; when the above particle size is greater than 500nm, sedimentation is easy to occur during the film preparation process, making it difficult to achieve uniform luminescence of the quantum dot film. significantly improved. The size of the above-mentioned mesopores is 5 to 15nm, which can make full use of the spatial confinement effect to inhibit the agglomeration of quantum dots and avoid reabsorption between quantum dots; the above-mentioned mesopores can When the pore size is less than 5nm, the quantum dots have a greater barrier when entering the mesopores, and the utilization efficiency of the mesopores is low; when the mesopore size is greater than 15nm, when too many quantum dots are gathered, the quantum dots are prone to agglomeration and agglomeration in the mesopores. reabsorption, causing its fluorescence to be quenched.

The transparent oxide shell used in this application can choose materials containing super chemical stability, high light transmittance, high refractive index, etc., which can not only effectively isolate the erosion of quantum dots by water and oxygen, but also change the local structure of quantum dots. Domain light field intensity improves the blue light absorption rate and luminous efficiency of quantum dots. , in some embodiments, the oxide in the transparent oxide shell includes at least one selected from the group consisting of silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, and nickel oxide. kind.

The main function of the organic polymer used in this application is to form a film as a framework material and change the local light field distribution to improve the photon extraction efficiency. Therefore, any organic polymer that can achieve this function can be considered for use in this application. In some implementations For example, the organic polymer includes at least one selected from the group consisting of polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, polyvinylidene fluoride, and polyethyleneimine.

1) The mass percentage of quantum dots relative to the nano-mesoporous spheres is 1 to 30 wt%, optionally 10 to 20 wt%. It can avoid excessive dosage of quantum dots causing aggregation and triggering fluorescence quenching after aggregation.

2) The mass percentage of the core-shell structure relative to the organic polymer is 1 to 25 wt%, and optionally 2 to 15 wt%. Optimize the film-forming performance of subsequent quantum dot luminescent films.

3) The thickness of the transparent oxide shell is 5~100nm, optionally 10~50nm. It can balance the luminescence performance and stability of quantum dots to avoid a decrease in luminescence performance caused by excessive thickness, and insufficient improvement in stability due to excessive thickness.

The beneficial effects of the present application will be further described below in conjunction with examples and comparative examples.

Example 1

(1) Weigh 20 mg of green CdSe/ZnCdS/ZnS quantum dots and 100 mg of mesoporous silica (mSiO ₂ , size 100 nm, mesopores 10 nm) and add them to 10 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 A homogeneous solution is formed after 1 minute;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain CdSe/ZnCdS/ZnS@mSiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(3) Add 100 μL of tetraethyl orthosilicate (TEOS), 20 mL of ethanol, 1 mL of deionized water, and 1 mL of ammonia to mixed solution 1, stir thoroughly and let stand for 6 hours to form solution 3;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CdSe/ZnCdS/ZnS@mSiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL toluene solution , a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(5) Dissolve 500 mg of PMMA in 1 mL of toluene solution to obtain mixed solution 5;

(6) Add mixed solution 5 to mixed solution 4, and stir for 30 minutes at a magnetic stirring speed of 1000 rpm to form a uniform mixed solution 6;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mSiO ₂ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 1 is shown in Table 1.

Example 2

(1) Weigh 20 mg of green CsPbBr ₃ quantum dots and 100 mg of mesoporous silica (mSiO ₂ , size 100 nm, mesopores 10 nm) and add them to 10 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 minutes to form Homogeneous solution 1;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain CsPbBr ₃ @mSiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CsPbBr ₃ @mSiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL of toluene solution. A homogeneous solution 4 was formed after 30 minutes of magnetic stirring at 1000 rpm;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CsPbBr3@mSiO ₂ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 2 are shown in Table 1.

Example 3

(3) Add 100 μL of tetraethyl orthosilicate (TEOS), 20 mL of ethanol, and 1 mL of deionized solution 1. Substitute water and 1 mL of ammonia water, stir thoroughly and let stand for 6 hours to form solution 3;

(5) Dissolve 500 mg of PVDF in 1 mL of toluene solution to obtain mixed solution 5;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mSiO ₂ /SiO ₂ @PVDF quantum dot luminescent film with a thickness of 200 μm. The test data of Example 3 are shown in Table 1.

Example 4

(1) Weigh 20 mg of red InP/ZnSe/ZnS quantum dots and 100 mg of mesoporous silica (mSiO ₂ , size 100 nm, mesopores 10 nm) and add them to 10 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 A homogeneous solution is formed after 1 minute;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain InP/ZnSe/ZnS@mSiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as red InP/ZnSe/ZnS@mSiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL toluene solution , a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green InP/ZnSe/ZnS@mSiO ₂ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 4 are shown in Table 1.

Example 5

(3) Add 100 μL of aluminum sec-butoxide and 20 μL ammonia water to mixed solution 1, stir thoroughly and let stand for 6 hours to form solution 3;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CdSe/ZnCdS/ZnS@mSiO ₂ /Al ₂ O ₃ nanospheres, and redisperse them into 10 mL. In the toluene solution, a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mSiO ₂ /Al ₂ O ₃ @PMMA quantum dot luminescent film with a thickness of 200μm. The test data of Example 5 are shown in Table 1.

Example 6

(1) Weigh 20 mg of green CdSe/ZnCdS/ZnS quantum dots and 100 mg of mesoporous aluminum trioxide (mAl ₂ O ₃ , size 100 nm, mesopores 10 nm) and add them to 10 mL of toluene solution, stirring at 1000 rpm with magnetic force. A homogeneous solution 1 was formed after 30 minutes;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain CdSe/ZnCdS/ZnS@mAl ₂ O ₃ nanospheres, and redisperse the nanospheres in the toluene solution to form a mixed solution 2;

(4) Add solution 3 to the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CdSe/ZnCdS/ZnS@mAl ₂ O ₃ /Al ₂ O ₃ nanospheres, and redisperse them into 10 mL of toluene solution, and then formed a uniform solution 4 under magnetic stirring at 1000 rpm for 30 minutes;

(7) Place the mixed solution 6 on the scraper, and use the scraper coating method to heat at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mAl ₂ O ₃ /Al ₂ O ₃ @PMMA quantum dot luminescent film. The thickness is 200μm. Example The test data of 6 are shown in Table 1.

Example 7

(3) Add 100 μL of tetraethyl orthosilicate (TEOS), 20 mL of ethanol, 1 mL of deionized water and 1 mL of ammonia to mixed solution 2, stir thoroughly and let stand for 6 hours to form solution 3;

(4) Add solution 3 to the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green InP/ZnSe/ZnS@mAl ₂ O ₃ /SiO ₂ nanospheres, and redisperse them to 10 mL. In the toluene solution, a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mAl ₂ O ₃ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200μm. The test data of Example 7 is shown in Table 1.

Example 8

(1) Weigh 20 mg of green InP/GaP/ZnS quantum dots and 100 mg of mesoporous titanium oxide (mTiO ₂ , size 100 nm, mesopores 10 nm) and add them to 10 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 minutes. Finally, a uniform solution 1 is formed;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain InP/GaP/ZnS@mTiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green InP/GaP/ZnS@mTiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL toluene solution , a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(5) Dissolve 500 mg of polyvinyl alcohol (PVA) in 1 mL of toluene solution to obtain mixed solution 5;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green InP/GaP/ZnS@mTiO ₂ /SiO ₂ @PVA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 8 are shown in Table 1.

Example 9

(1) Weigh 30 mg of red Rb ₂ PbI ₄ quantum dots and 200 mg of mesoporous titanium oxide (mTiO ₂ , size 100 nm, mesopores 10 nm) and add them to 10 mL of chloroform solution, and stir under magnetic stirring at 1000 rpm for 30 minutes. Form a homogeneous solution 1;

(2) Add solution 1 into the centrifuge tube, centrifuge at 3000 rpm for 5 minutes to obtain Rb ₂ PbI ₄ @mTiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(3) Add 100 μL of butyl titanate, 20 mL of ethanol, 1 mL of deionized water and 1 mL of hydrochloric acid to mixed solution 2, stir thoroughly and let stand for 6 hours to form solution 3;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green Rb ₂ PbI ₄ @mTiO ₂ /TiO ₂ nanospheres, and redisperse them into 10 mL toluene solution , a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(5) Dissolve 1 mL of polyethyleneimine (PEI) in 1 mL of toluene-chloroform mixed solution to obtain mixed solution 5;

(7) Place the mixed solution 6 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green Rb ₂ PbI ₄ @mTiO ₂ /TiO ₂ @PEI quantum dot luminescent film with a thickness of 200 μm. The test data of Example 9 is shown in Table 1.

Example 10

(1) Weigh 20 mg of red CsPbBr _1.8 I _1.2 quantum dots and 100 mg of mesoporous silicon oxide (mSiO ₂ , size 200 nm, mesopores 15 nm) and add them to 10 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 minutes. Form a homogeneous solution 1;

(2) Add solution 1 into the centrifuge tube, centrifuge at 2000 rpm for 5 minutes to obtain CsPbBr _1.8 I _1.2 @mSiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(3) Add 100 μL of tetraethyl orthosilicate (TEOS), 20 mL of ethanol, 1 mL of deionized water and 0.5 mL of nitric acid to mixed solution 2, stir thoroughly and let stand for 6 hours to form solution 3;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as red CsPbBr _1.8 I _1.2 @mSiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL cyclohexane In the solution, a uniform solution 4 was formed after 30 minutes of magnetic stirring at 1000 rpm;

(5) Dissolve 800 mg of PMMA in 1 mL of toluene solution to obtain mixed solution 5;

(7) Place the mixed solution 6 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a red CsPbBr _1.8 I _1.2 @mSiO ₂ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 10 are shown in Table 1.

Example 11

(1) Weigh 30 mg of yellow CdSe/CdS/ZnS quantum dots and 200 mg of mesoporous silicon oxide (mSiO ₂ , size 500 nm, mesopores 20 nm) and add them to 15 mL of toluene solution, and stir under magnetic stirring at 1000 rpm for 30 minutes. Finally, a uniform solution 1 is formed;

(2) Add solution 1 into the centrifuge tube, centrifuge at 2000 rpm for 5 minutes to obtain CdSe/CdS/ZnS@mSiO ₂ nanospheres, and redisperse the nanospheres in the toluene solution to form mixed solution 2;

(3) Add 500 μL of tetraethyl orthosilicate (TEOS), 60 mL of ethanol, 3 mL of deionized water and 1 mL of hydrochloric acid to mixed solution 2, stir thoroughly and let stand for 10 hours to form solution 3;

(4) Add solution 3 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as yellow CdSe/CdS/ZnS@mSiO ₂ /SiO ₂ nanospheres, and redisperse them into 10 mL toluene solution , a uniform solution 4 was formed after 30 minutes under magnetic stirring at 1000 rpm;

(7) Place the mixed solution 6 on the scraper, use the scraper coating method and heat it at 120°C for 30 minutes to prepare a yellow CdSe/CdS/ZnS@mSiO ₂ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm. The test data of Example 11 are shown in Table 1.

Example 12

(1) The green and red quantum dot luminescent films of Example 1 and 10 are extruded, heated to 120°C and kept for 15 minutes to form a new quantum dot luminescent film;

(2) Cover the new quantum dot luminescent film on a 4×4 array of blue Mini-LED chips, where the size of each blue Mini-LED chip is 100×200 μm;

(3) Driven by a 6V DC power supply, the blue Mini-LED array excites the red and green quantum dot films to emit red and green light, thereby compounding bright white light. The electroluminescence spectrum is shown in Figure 2.

Comparative example 1

(1) Disperse 10 mg of green CdSe/ZnCdS/ZnS quantum dots in 10 mL of toluene solution to obtain mixed solution 1;

(2) Dissolve 500 mg of polymethyl methacrylate (PMMA) in 1 mL of toluene solution to obtain mixed solution 2;

(3) Add mixed solution 2 to mixed solution 1 and stir for 30 minutes at a magnetic stirring speed of 1000 rpm to form a uniform mixed solution 3;

(4) Place the mixed solution 3 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 1 is that mesoporous silica is not used and a transparent oxide shell is not formed. Other operations are the same as Example 1. The test data of Comparative Example 1 is shown in Table 1.

Comparative example 2

(1) Disperse 10 mg of green CsPbBr ₃ quantum dots in 10 mL of toluene solution to obtain mixed solution 1;

(2) Dissolve 500 mg of PMMA in 1 mL of toluene solution to obtain mixed solution 2;

(4) Place the mixed solution 3 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CsPbBr ₃ @PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 2 is that mesoporous silica is not used and a transparent oxide shell is not formed. Other operations are the same as in Example 2. The test data of Comparative Example 2 is shown in Table 1.

Comparative example 3

(2) Dissolve 500 mg of polyvinylidene fluoride (PVDF) in 1 mL of toluene solution to obtain mixed solution 2;

(4) Place the mixed solution 3 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare green Color CdSe/ZnCdS/ZnS@PVDF quantum dot luminescent film with a thickness of 200μm.

The difference from Example 3 is that mesoporous silica is not used and a transparent oxide shell is not formed. Other operations are the same as Example 3. The test data of Comparative Example 3 are shown in Table 1.

Comparative example 4

(3) Dissolve 500 mg of PMMA in 1 mL of toluene solution to obtain mixed solution 3;

(4) Add mixed solution 3 to mixed solution 2, and stir for 30 minutes at a magnetic stirring speed of 1000 rpm to form a uniform mixed solution 4;

(5) Place the mixed solution 4 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mSiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 1 is that no transparent oxide shell layer is formed, and other operations are the same as Example 3. The test data of Comparative Example 4 is shown in Table 1.

Comparative example 5

(5) Place the mixed solution 4 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CsPbBr ₃ @mSiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 2 is that no transparent oxide shell layer is formed, and other operations are the same as Example 3. The test data of Comparative Example 5 are shown in Table 1.

Comparative example 6

(3) Dissolve 500 mg of PVDF in 1 mL of toluene solution to obtain mixed solution 3;

(5) Place the mixed solution 4 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS@mSiO ₂ @PVDF quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 3 is that no transparent oxide shell layer is formed, and other operations are the same as Example 3. The test data of Comparative Example 6 are shown in Table 1.

Comparative example 7

(1) Weigh 10 mg of green CdSe/ZnCdS/ZnS quantum dots and disperse them into 10 mL of toluene to form mixed solution 1;

(2) Add 100 μL of tetraethyl orthosilicate (TEOS), 20 mL of ethanol, 1 mL of deionized water and 1 mL of ammonia to mixed solution 1, stir thoroughly and let stand for 6 hours to form solution 2;

(3) Add solution 2 into the centrifuge tube and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CdSe/ZnCdS/ZnS/SiO ₂ nanospheres, and redisperse them into 10 mL of toluene solution. A uniform solution 3 was formed after 30 minutes of magnetic stirring at 1000 rpm;

(4) Dissolve 500 mg of PMMA in 1 mL of toluene solution to obtain mixed solution 4;

(5) Add mixed solution 4 into mixed solution 3, and stir for 30 minutes at a magnetic stirring speed of 1000 rpm to form a uniform mixed solution 5;

(6) Place the mixed solution 5 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS/SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 1 is that mesoporous silica is not used, and other operations are the same as Example 1. The test data of Comparative Example 7 is shown in Table 1.

Comparative example 8

(1) Weigh 10 mg of green CsPbBr ₃ quantum dots and disperse them into 10 mL of toluene to form mixed solution 1;

(3) Add solution 2 into the centrifuge tube, and centrifuge at 5000 rpm for 10 minutes to obtain the precipitate as green CsPbBr ₃ /SiO ₂ nanospheres, and redisperse them into 10 mL toluene solution, and use magnetic force at 1000 rpm A uniform solution 3 was formed after stirring for 30 minutes;

(6) Place the mixed solution 5 on a scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CsPbBr ₃ /SiO ₂ @PMMA quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 2 is that mesoporous silica is not used, and other operations are the same as Example 2. The test data of Comparative Example 8 is shown in Table 1.

Comparative example 9

(4) Dissolve 500 mg of PVDF in 1 mL of toluene solution to obtain mixed solution 4;

(6) Place the mixed solution 5 on the scraper, use the scraper coating method and heat it at 100°C for 20 minutes to prepare a green CdSe/ZnCdS/ZnS/SiO ₂ @PVDF quantum dot luminescent film with a thickness of 200 μm.

The difference from Example 3 is that mesoporous silica is not used, and other operations are the same as Example 3. The test data of Comparative Example 9 is shown in Table 1.

Example 13

Mesoporous silica (mSiO ₂ , size 50nm, mesopores 5nm) is used to replace the mesoporous silica of Example 1, The remaining operations are the same as in Example 1.

Example 14

Mesoporous silica (mSiO ₂ , size 500 nm, mesopores 15 nm) was used to replace the mesoporous silica in Example 1, and the remaining operations were the same as in Example 1.

Example 15

Mesoporous silica (mSiO ₂ , size 500 nm, mesopores 20 nm) was used to replace the mesoporous silica in Example 1, and the remaining operations were the same as in Example 1.

Example 16

The SiO ₂ shell layer in Example 1 was replaced with a SiO ₂ shell layer with a thickness of 50 nm, and the remaining operations were the same as in Example 1.

Example 17

The SiO ₂ shell layer in Example 1 is replaced with a SiO ₂ shell layer with a thickness of 100 nm, and the remaining operations are the same as in Example 1.

Example 18

Use more CdSe/ZnCdS/ZnS quantum dots (the mass ratio of CdSe/ZnCdS/ZnS to mSiO ₂ is 20%) to replace the quantum dots in Example 1, and the remaining operations are the same as in Example 1.

Example 19

Use less CdSe/ZnCdS/ZnS@mSiO ₂ /SiO ₂ (CdSe/ZnCdS/ZnS@mSiO ₂ /

The ratio of SiO ₂ to PMMA was reduced to 2%), and the remaining operations were the same as in Example 1.

Example 20

Use more CdSe/ZnCdS/ZnS@mSiO ₂ /SiO ₂ (CdSe/ZnCdS/ZnS@mSiO ₂ /

The ratio of SiO ₂ to PMMA was increased to 15%), and the remaining operations were the same as in Example 1.

Example 21

Use more PMMA to make the thickness of the quantum dot luminescent film 500 μm, and the remaining operations are the same as in Example 1.

Example 22

Use more PMMA to make the thickness of the quantum dot luminescent film 600 μm, and the remaining operations are the same as in Example 1.

Example 23

Reduce the amount of PMMA so that the thickness of the quantum dot luminescent film is 100 μm, and the remaining operations are the same as in Example 1.

Example 24

The amount of PMMA was reduced so that the thickness of the quantum dot luminescent film was 70 μm, and the remaining operations were the same as in Example 1.

Comparative example 10

Microporous silica (mSiO ₂ , size 100 nm, mesopores 1.5 nm) was used to replace the mesoporous silica in Example 1, and the remaining operations were the same as in Example 1.

Comparative example 11

Macroporous silica (mSiO ₂ , size 200 nm, mesopores 55 nm) was used to replace the mesoporous silica in Example 1, and the remaining operations were the same as in Example 1.

The brightness test method is: place the sample in an environment with an ambient temperature of 25°C and a humidity of about 50%, and use a blue LED as the excitation light source (optical power density 150mW/cm2), and a 3.5-inch integrating sphere and a fiber spectrometer ( Ocean Optics QEPro) is integrated to obtain the brightness of the sample.

The test method for the brightness after double 85 and high power density blue light radiation is: place the sample in an environment with a humidity of 85% and a temperature of 85°C, and use a blue LED as the excitation light source (optical power density 150mW/cm ² ). Integrated with a 3.5-inch integrating sphere and fiber spectrometer (Ocean Optics QEPro) to obtain double 85 and high power density blue light radiation brightness of the sample.

The composition test method of quantum dot luminescent film: (1) Use a transmission electron microscope (TEM) to confirm that the quantum dots enter the mesopores of the mesoporous spheres; (2) Obtain the quantum dots by comparing the mass of the nano-mesoporous spheres before and after physical adsorption and the mass percentage of nano mesoporous spheres; (3) Weigh the mass of nano spheres M@N/P and M@N/P@Q films respectively to calculate the mass percentage of nano spheres M@N/P and organic polymer @ percentage; (4) Use a transmission electron microscope to detect the thickness of the P layer.

The mass percentage of quantum dots and nano-mesoporous spheres is marked as A; the mass percentage of nano-microspheres M@N/P and organic polymer film Q is marked as B.

The test results are recorded in Table 1.

Claims

A quantum dot luminescent film, characterized in that the quantum dot luminescent film is made of quantum dot luminescent material. The quantum dot luminescent material is made by embedding quantum dots in the pores on the surface of nano mesoporous spheres, and then wrapping the surface with transparent The oxide shell is finally formed by being embedded in an organic polymer; its general chemical formula is: M@N/P@Q; where M is a quantum dot; @ means embedded; N is a nanometer mesoporous sphere; / means core shell; P is a transparent oxide shell; Q is an organic polymer.
The quantum dot luminescent film according to claim 1, characterized in that the quantum dots are ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, InP/ZnSe /ZnS, InP/GaP/ZnS, at least one of ABX 3 , A 2 BX 4 quantum dots; where A is Cs, Rb, methylamine, formamidine, hexylamine, octylamine, dodecaamine, phenylethylamine , at least one of benzylamine, ethylenediamine, and amphetamine, B is at least one of Pb, Sn, and Mn, X is at least one of Cl, Br, and I; the particle size is 3 to 20 nm.
The quantum dot luminescent film according to claim 1, wherein the nano mesoporous spheres are at least one of mesoporous silica, mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconia; the particle size is 50~500nm, mesopore size is 5~15nm.
The quantum dot luminescent film according to claim 1, wherein the oxide in the transparent oxide shell is silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, oxide At least one of nickel.
The quantum dot luminescent film according to claim 1, wherein the organic polymer is polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, polyvinylidene fluoride, polyvinylidene fluoride, At least one kind of ethylene imine.
The quantum dot luminescent film according to any one of claims 1 to 5, characterized in that the quantum dot luminescent film satisfies at least one of the following conditions:

1) The mass percentage of the quantum dots M and the nano-mesoporous spheres N is 1 to 30 wt%, optionally 10 to 20 wt%;

2) The mass percentage of the nanospheres M@N/P and the organic polymer film Q is 1 to 25 wt%, optionally 2 to 15 wt%;

3) The thickness of the P layer is 5~100nm, optionally 10~50nm;

4) The thickness of the quantum dot luminescent film is 100 to 500 μm.
A method for preparing the quantum dot luminescent film according to any one of claims 1 to 6, characterized in that it includes the following steps:

S1, embed quantum dots M into the surface pores of nano-mesoporous spheres N through physical adsorption to form M@N composite nanospheres;

S2, disperse the M@N composite nanospheres into a non-polar solvent, add the transparent oxide shell P precursor, water, catalyst and ethanol, and use the hydrolysis reaction to wrap the P layer on the M@N surface to close the mesoporous channels. Form M@N/P nanosphere solution;

S3, dissolve the organic polymer Q to form a uniform sol, add the M@N/P nanoparticle solution into the above sol, and stir thoroughly to form a uniform mixed sol. After extrusion and solidification, the M@N/P nanoparticles Embedding organic polymer Q, the final product M@N/P@Q quantum dot luminescent film is obtained.
The preparation method according to claim 7, characterized in that the mass percentage of the quantum dots M and nano-mesoporous spheres N is 1 to 30 wt%.
The preparation method according to claim 7, characterized in that the mass percentage of the nanospheres M@N/P and the organic polymer film Q is 1 to 25 wt%, optionally 2 to 15 wt%.
The preparation method according to claim 7, characterized in that the thickness of the P layer is 5-100 nm, optionally 10-50 nm.
A white light Mini-LED device, characterized by comprising the quantum dot luminescent film according to any one of claims 1 to 10.
A quantum dot luminescent material, characterized in that the quantum dot luminescent material includes quantum dots, nanometer mesoporous spheres, a transparent oxide shell and an organic polymer, wherein the quantum dots are embedded in the nanometer mesoporous spheres. M@N composite nanospheres are formed in the surface pores, and the transparent oxide shell coats the surface of the M@N composite nanospheres to form a core-shell structure. The core-shell structure is dispersed in the organic polymer.
The quantum dot luminescent material according to claim 12, characterized in that the general chemical formula of the quantum dot luminescent material is: M@N/P@Q; where M is a quantum dot; @ represents embedded; N is a nanometer medium Hole ball; / represents core shell; P is transparent oxide shell; Q is organic polymer.
The quantum dot luminescent material according to claim 12 or 13, characterized in that the quantum dots include ZnSeTe/ZnS, ZnCdSe/CdS/ZnS, CdSe/CdS/ZnS, CdSe/CdZnS/ZnS, ZnCdS/ZnS, At least one selected from the group consisting of InP/ZnSe/ZnS, InP/GaP/ZnS, ABX 3 , and A 2 BX 4 quantum dots; wherein A includes Cs, Rb, methylamine, formamidine, hexylamine, At least one selected from the group consisting of octylamine, dodecylamine, phenethylamine, benzylamine, ethylenediamine, and amphetamine, and B includes at least one selected from the group consisting of Pb, Sn, and Mn, X includes at least one selected from the group consisting of Cl, Br, and I, and/or the particle size of the quantum dot is 3 to 20 nm.
The quantum dot luminescent material according to any one of claims 12 to 14, characterized in that the nano mesoporous spheres are composed of mesoporous silica, mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconia. At least one selected from the group; and/or the particle size of the nano-mesoporous spheres is 50 to 500 nm; and/or the mesopore size of the nano-mesoporous spheres is 5 to 15 nm.
The quantum dot luminescent material according to any one of claims 12 to 15, characterized in that the oxide in the transparent oxide shell layer includes silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide, At least one selected from the group consisting of magnesium oxide, cerium oxide, and nickel oxide.
The quantum dot luminescent material according to any one of claims 12 to 16, characterized in that the organic polymer includes polymethyl methacrylate, polyvinyl alcohol, polyethylene terephthalate, Polyvinylidene fluoride, poly At least one selected from the group consisting of ethyleneimines.
The quantum dot luminescent material according to any one of claims 12 to 17, characterized in that the quantum dot luminescent material satisfies at least one of the following conditions:

1) The mass percentage of the quantum dots relative to the nano mesoporous spheres is 1 to 30 wt%, optionally 10 to 20 wt%;

2) The mass percentage of the core-shell structure relative to the organic polymer is 1 to 25 wt%, optionally 2 to 15 wt%;

3) The thickness of the transparent oxide shell is 5 to 100 nm, optionally 10 to 50 nm.