Quantum dot aerogel composite material, quantum dot light-emitting device and preparation method of quantum dot light-emitting device

Abstract

The invention provides quantum dot aerogel, a quantum dot light-emitting device and a preparation method thereof, and the preparation method comprises the following steps: adding a silane coupling agent into quantum dots to form modified quantum dots with silanol groups on the surfaces; uniformly stirring a silicon dioxide precursor and absolute ethyl alcohol, slowly adding deionized water and a catalyst, and stirring to form silicon dioxide sol; adding the modified quantum dots into silicon dioxide sol to form a mixed solution; placing the mixed solution in a closed container, and standing to form gel; putting the gel into absolute ethyl alcohol for aging treatment; and carrying out supercritical drying treatment on the aged gel to obtain the quantum dot aerogel composite material. The light-emitting performance of the quantum dots and the heat insulation performance of the aerogel are perfectly combined, the high temperature resistance and blue light resistance of the quantum dot aerogel composite material film layer can be greatly improved, the preparation method is simple, and the application range of the quantum dots can be greatly widened.

Description

Technical Field

[0001] This invention belongs to the field of quantum dot technology, and particularly relates to a quantum dot aerogel composite material, a quantum dot light-emitting device, and a method for preparing the same. Background Technology

[0002] Quantum dots (QDs) are nanomaterials with unique optical and electronic properties, such as quantum confinement and fluorescence. Due to their size being smaller than the de Broglie wavelength, quantum dots show great potential for applications in optoelectronics, photocatalysis, and biolabeling. The energy level structure of quantum dots can be precisely controlled by manipulating their size and shape, giving them unique luminescence properties at specific wavelengths. Aerogels are highly porous solid materials with extremely low density and excellent thermal insulation properties. Their internal nanoporous structure gives them significant advantages in physical and chemical applications, such as thermal insulation materials, catalyst supports, and sensor substrates.

[0003] In existing technologies, in applications of quantum dots, such as Micro LED, QLED, and displays, the solutions that combine quantum dots with aerogel can be broadly categorized into two types: (1) using aerogel as a heat-insulating material (under the quantum dots) and then filling the aerogel with quantum dots to achieve a heat-insulating effect; (2) filling the gaps in the aerogel with quantum dots to achieve aerogel encapsulation of the quantum dots. However, in practical applications, the method of the first type is complex to prepare and cannot be implemented on small-sized display devices, while the second type greatly reduces the heat-insulating effect of the aerogel. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a quantum dot aerogel composite material, a quantum dot light-emitting device, and a method for preparing the same.

[0005] To achieve the above objectives, the present invention provides a method for preparing a quantum dot aerogel composite material, the method comprising:

[0006] Step S1: Add a silane coupling agent to the quantum dots and perform surface modification treatment on the quantum dots to form modified quantum dots with silanol groups on the surface.

[0007] Step S2: Mix the silica precursor and anhydrous ethanol in a set ratio and stir until homogeneous. Then slowly add deionized water and catalyst and stir at room temperature to form a uniform and transparent silica sol.

[0008] Step S3: Slowly add the uniformly dispersed modified quantum dots into the silica sol, and stir or sonicate for more than 30 minutes to ensure that the modified quantum dots are uniformly dispersed in the silica sol to form a mixed solution;

[0009] Step S4: Place the mixed solution in a sealed container and let it stand for a first specific time (e.g., 1h to 24h) to allow it to form a gel;

[0010] Step S5: The gel is placed in anhydrous ethanol for aging treatment for a second specific time (e.g., 1 to 3 days), and the water and residual silica precursor in the gel are replaced multiple times with anhydrous ethanol or n-hexane.

[0011] Step S6: The aged gel is subjected to supercritical drying to obtain a quantum dot aerogel composite material.

[0012] As an optional technical solution, step S1 includes:

[0013] Step S11: Disperse the quantum dots in hexane or ethanol solvent, and remove the weakly adsorbed substances on the surface of the quantum dots by centrifugation to obtain a quantum dot solution.

[0014] Step S12: Dissolve the silane coupling agent in anhydrous ethanol, add a small amount of water, and stir to partially hydrolyze the silane coupling agent to generate silanol groups, thereby obtaining a silane coupling agent solution.

[0015] Step S13: Add the quantum dot solution to the silane coupling agent solution, stir at 60°C for 12-24 hours, and protect with nitrogen to prevent silane polymerization to obtain a reaction solution;

[0016] Step S14: Centrifuge the reaction solution, wash the reaction solution with anhydrous ethanol and isopropanol respectively to remove silane coupling agent that is not bound to the surface of the quantum dots; and dry the reaction solution in a vacuum drying oven to obtain the modified quantum dots with silanol groups on the surface.

[0017] As an optional technical solution, in step S2, the volume ratio of the silica precursor to the anhydrous ethanol is 1:4, the molar ratio of the deionized water to the silica precursor is 1:4, and the molar concentration of the catalyst is 0.01 mol / L.

[0018] As an optional technical solution, the mass percentage concentration of the modified quantum dots is 0.01% to 0.1%.

[0019] As an optional technical solution, the quantum dots are selected from one or a mixture of several of CdSe / ZnS quantum dots, CdTe quantum dots, PbS quantum dots, carbon quantum dots, and perovskite quantum dots.

[0020] As an optional technical solution, the silane coupling agent is selected from at least one of 3-aminopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0021] As an optional technical solution, the silica precursor is tetraethoxysilane, and the catalyst is a dilute acid or a dilute alkali.

[0022] As an optional technical solution, the critical conditions for the supercritical drying process are: a temperature of 40°C, a pressure of 7-10 MPa, and a drying medium of carbon dioxide or nitrogen.

[0023] As an optional technical solution, step S1 further includes: stirring the mixture of the quantum dots and the silane coupling agent for more than 2 hours, so that the surface of the modified quantum dots has silanol groups and exposes dynamic bond groups; step S2 further includes: adding a dynamic bond auxiliary agent to the silica sol and stirring evenly, so that the silica sol has dynamic response characteristics; in step S3, the modified quantum dots and the silica sol undergo a dynamic crosslinking reaction to form a mixed solution with a dynamic network.

[0024] As an optional technical solution, the dynamic bond auxiliary reagent is selected from phenylboronic acid solution, o-dialdehyde solution, and Fe-containing metal ions. 3+ or Zn 2+ The solution.

[0025] The present invention also provides a quantum dot aerogel composite material, which is prepared by the preparation method described above.

[0026] The present invention also provides a quantum dot light-emitting device, including a substrate and a quantum dot aerogel composite material film layer disposed in cooperation with the substrate. The substrate includes light-emitting units arranged in an array. The quantum dot aerogel composite material film layer is formed on the substrate such that the light-emitting surface of the light-emitting unit is covered by the quantum dot aerogel composite material film layer. The quantum dot aerogel composite material film layer is formed by forming the quantum dot aerogel composite material as described above on the substrate and then performing an exposure and development process or an etching process.

[0027] The present invention also provides a method for fabricating the quantum dot light-emitting device as described above, the method comprising the following steps:

[0028] A passivation layer is formed on the substrate;

[0029] The first mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer;

[0030] Steps S4, S5 and S6 are performed on the first mixed solution spin-coated onto the passivation layer to obtain the first color quantum dot aerogel composite material.

[0031] The first color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film layer in a first region of the substrate.

[0032] As an optional technical solution, the preparation method further includes:

[0033] The second mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer;

[0034] Steps S4, S5 and S6 are performed on the second mixed solution to obtain a second color quantum dot aerogel composite material.

[0035] The second color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a second color quantum dot aerogel composite material film layer in the second region of the substrate, and the first region and the second region do not overlap.

[0036] As an optional technical solution, the fabrication method of the quantum dot light-emitting device includes the following steps:

[0037] A passivation layer is formed on the substrate;

[0038] The first mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer;

[0039] Step S4 is performed on the first mixed solution spin-coated onto the passivation layer;

[0040] After mixing and stirring the first gel obtained in step S4 with the photoresist, continue to execute steps S5 and S6 to obtain a first color quantum dot aerogel composite material mixed with photoresist.

[0041] The first color quantum dot aerogel composite material mixed with photoresist is patterned by an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film mixed with photoresist in a first region of the substrate.

[0042] As an optional technical solution, the preparation method further includes:

[0043] The second mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer;

[0044] Step S4 is performed on the second mixed solution;

[0045] After mixing and stirring the second gel obtained in step S4 with the photoresist, continue to execute steps S5 and S6 to obtain a second color quantum dot aerogel composite material mixed with photoresist.

[0046] The second color quantum dot aerogel composite material mixed with photoresist is patterned using an exposure and development process or an etching process to form a second color quantum dot aerogel composite material film mixed with photoresist in the second region of the substrate, wherein the first region and the second region do not overlap.

[0047] Compared with existing technologies, this invention uniformly disperses modified quantum dots into silica sol, allowing them to covalently or physically bond with the silica network during gelation, or form a dynamic network, thereby creating a highly stable quantum dot aerogel composite material. Furthermore, the modified quantum dots enhance the compatibility between the quantum dots and the silica network, forming robust bonds. In addition, supercritical drying can create a composite material where the aerogel framework encapsulates the quantum dots, avoiding capillary action and preserving the photoelectric properties of the quantum dots and the high porosity of the aerogel.

[0048] Moreover, the quantum dot aerogel composite material with a porous structure obtained by the present invention perfectly combines the luminescent properties of quantum dots and the thermal insulation properties of aerogel, which can greatly improve the high temperature resistance and blue light resistance of the quantum dot aerogel composite film. In addition, the preparation method of the present invention is simple and can be applied to display devices of different sizes (especially small sizes), greatly expanding the application range of quantum dots. Attached Figure Description

[0049] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating a method for preparing a quantum dot aerogel composite material according to an embodiment of the present invention;

[0051] Figure 2 This is a SEM image of the quantum dot aerogel membrane layer in Example 1 of the present invention. Detailed Implementation

[0052] To provide a further understanding of the purpose, structure, features, and functions of the present invention, detailed descriptions are provided below with reference to specific embodiments.

[0053] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for preparing a quantum dot aerogel composite material according to an embodiment of the present invention. The present invention provides a method for preparing a quantum dot aerogel composite material, the method comprising the following steps:

[0055] Step S1: Add a silane coupling agent to the quantum dots and perform surface modification treatment on the quantum dots to form modified quantum dots with silanol groups on the surface.

[0056] The silane coupling agent is selected from at least one of 3-aminopropyltriethoxysilane (APTES) and 3-mercaptopropyltrimethoxysilane (MPTMS).

[0057] Step S2: Mix the silica precursor and anhydrous ethanol in a predetermined ratio and stir until homogeneous. Then, slowly add deionized water and catalyst, and stir at room temperature to form a uniform and transparent silica sol. The stirring time can be determined according to the actual situation, for example, 1 hour.

[0058] The silica precursor is, for example, tetraethoxysilane (TEOS) or tetraethyl orthosilicate. The catalyst is, for example, a dilute acid (such as HCl) or a dilute base (such as NH3·H2O). Preferably, the volume ratio of the silica precursor to the anhydrous ethanol is 1:4, the molar ratio of the deionized water to the silica precursor is 1:4, and the molar concentration of the catalyst is 0.01 mol / L.

[0059] Step S3: Slowly add the uniformly dispersed modified quantum dots into the silica sol and stir or sonicate for more than 30 minutes to ensure that the modified quantum dots are uniformly dispersed in the silica sol to form a mixed solution.

[0060] The mass percentage concentration of the modified quantum dots is, for example, 0.01% to 0.1%. In practical applications, the specific concentration of the modified quantum dots can be determined according to the target use of the quantum dot aerogel composite material.

[0061] Step S4: Place the mixed solution in a sealed container and let it stand for a first specific time, such as 1 hour to 24 hours, to allow it to form a gel; the formed gel should be uniform and transparent, without obvious agglomeration. The specific standing time can be adjusted according to the viscosity of the mixed solution and the catalyst concentration.

[0062] Step S5: The gel is placed in anhydrous ethanol for a second specific time, such as 1 to 3 days, to enhance the strength of the network structure, and the water and residual silica precursor in the gel are replaced multiple times with anhydrous ethanol or n-hexane.

[0063] Step S6: The aged gel is subjected to supercritical drying to obtain a quantum dot aerogel composite material.

[0064] The critical conditions for the supercritical drying process are, for example, a temperature of approximately 40°C and a pressure of 7-10 MPa. Furthermore, the drying medium is, for example, nitrogen or carbon dioxide. Supercritical drying can form a composite material with an aerogel framework encapsulating quantum dots, avoiding capillary action and retaining the photoelectric properties of the quantum dots and the high porosity of the aerogel.

[0065] Furthermore, the quantum dots are selected, for example, from CdSe / ZnS quantum dots, CdTe quantum dots, PbS quantum dots, carbon quantum dots, and perovskite quantum dots, and these quantum dots have hydrophobic or hydrophilic surface modifications.

[0066] In step S1, the introduction of silanol groups can improve the compatibility between quantum dots and the silica network. Specifically, after adding a silane coupling agent to the quantum dots, the silanol groups (-Si(OCH3)3 or -Si(OC2H5)3) in the silane coupling agent will generate silanol groups (-SiOH) after hydrolysis by stirring. The silanol groups (-SiOH) can undergo a condensation reaction with the hydroxyl groups or other active groups on the surface of the quantum dots to form a stable covalent bond. That is, step S1 is the silanization modification step of quantum dots, so that the surface of the modified quantum dots has silanol groups.

[0067] Furthermore, some functional groups of silane coupling agents (such as -NH2 or -SH) can also provide further binding sites for quantum dots to bind with the silica network.

[0068] Furthermore, in the above-mentioned method for preparing quantum dot aerogel composite materials, modified quantum dots are uniformly dispersed in silica sol. Tetraethoxysilane (TEOS) gradually forms a Si-O-Si network structure through hydrolysis and condensation reactions, and then transforms into a solid gel through gelation. During this process, quantum dots (QDs) are uniformly distributed within the network. In other words, the modified quantum dots are covalently or physically bonded to the silica network during gelation. Specifically, the bonding mechanism between the modified quantum dots and the silica sol is as follows:

[0069] (1) Chemical combination:

[0070] The silanol groups (-SiOH) on the surface of the modified quantum dots covalently bond with the silanol groups (-SiOH) in the silica sol through a condensation reaction, forming a stable chemical bond.

[0071] QDs-SiOH+SiOH→QDs-Si-O-Si

[0072] (2) Physical embedding:

[0073] Modified quantum dots that are not covalently bonded to the silica network will be physically embedded into the silica network during the gelation process.

[0074] In addition, step S1 specifically includes the following steps:

[0075] Step S11: Disperse the quantum dots in hexane or ethanol solvent, and remove the weakly adsorbed substances on the surface of the quantum dots by centrifugation to obtain a quantum dot solution.

[0076] Step S12: Dissolve the silane coupling agent in anhydrous ethanol, add a small amount of water, and stir for 30 minutes or more to partially hydrolyze the silane coupling agent to generate silanol groups (-SiOH), thereby obtaining a silane coupling agent solution.

[0077] Step S13: Add the quantum dot solution to the silane coupling agent solution, stir at 60°C for 12-24 hours, and protect with nitrogen to prevent silane polymerization to obtain a reaction solution;

[0078] Step S14: Centrifuge the reaction solution, wash the reaction solution with anhydrous ethanol and isopropanol respectively to remove silane coupling agent that is not bound to the surface of the quantum dots; and dry the reaction solution in a vacuum drying oven to obtain the modified quantum dots with silanol groups on the surface, that is, the surface of the modified quantum dots is modified with silanol groups.

[0079] In another embodiment, step S1 further includes: stirring the mixture of the quantum dots and the silane coupling agent for 2 hours or more, so that the surface of the modified quantum dots has silanol groups and exposes dynamic bond groups (such as amino groups and thiol groups); step S2 further includes: adding a dynamic bond auxiliary agent to the silica sol and stirring evenly, so that the silica sol has dynamic response characteristics; in step S3, the modified quantum dots and the silica sol undergo a dynamic crosslinking reaction to form a mixed solution with a dynamic network. That is, in this embodiment, the modified quantum dots are combined with the silica (SiO2) gel network through dynamic crosslinking technology to form a quantum dot aerogel composite material with dynamic responsiveness and high stability.

[0080] The dynamic bond auxiliary reagent is selected, for example, from phenylboronic acid solution, o-dialdehyde solution, and Fe-containing metal ions. 3+ or Zn 2+ The solution.

[0081] Dynamic cross-linking reactions can be achieved, for example, through the following chemical bonds or interactions:

[0082] (1) Taking borate ester bonds as an example, borate groups and hydroxyl groups on the surface of modified quantum dots combine through a reversible reaction to form a dynamic network.

[0083] The chemical equation is:

[0084] The bonding strength of the above-mentioned bonding method is adjustable and has self-healing capabilities.

[0085] (2) Taking metal coordination bonds as an example, for instance, using Fe3+ + or Zn2 + Metal ions are used as bridges to connect modified quantum dots and silica networks.

[0086] The chemical equation is:

[0087]

[0088] The above-mentioned bonding method has strong dynamic response and the bonding strength can be controlled under acid, alkali or electric field conditions.

[0089] Of course, in addition to the above embodiments, other dynamic bonds, such as imine bonds (reaction of aldehydes and amines), hydrogen bonds, etc., can be used in other implementations to provide flexible binding modes.

[0090] In addition, the present invention also provides a quantum dot aerogel composite material, which is prepared by the quantum dot aerogel composite material preparation method described above.

[0091] In one embodiment, the present invention also provides a quantum dot light-emitting device, the quantum dot light-emitting device comprising a substrate and a quantum dot aerogel composite material film layer disposed in cooperation with the substrate, the substrate comprising light-emitting units arranged in an array, the quantum dot aerogel composite material film layer being formed on the substrate such that the light-emitting surface of the light-emitting units is covered by the quantum dot aerogel composite material film layer, the quantum dot aerogel composite material film layer being formed by forming the quantum dot aerogel composite material as described above on the substrate and then performing an exposure and development process or an etching process. That is, the light energy emitted by the light-emitting units is converted into light of other colors by the quantum dot aerogel composite material film layer. Moreover, the above-mentioned quantum dot aerogel composite material film layer may be provided with a first color quantum dot aerogel composite material film layer, a second color quantum dot aerogel composite material film layer, and a third color quantum dot aerogel composite material film layer according to the light-emitting element, the first color being, for example, green, the second color being, for example, red, and the third color being, for example, blue. The first-color quantum dot aerogel composite film converts the light emitted by the light-emitting element into corresponding red light emission; the second-color quantum dot aerogel composite film converts the light emitted by the light-emitting element into corresponding green light emission; and the third-color quantum dot aerogel composite film converts the light emitted by the light-emitting element into corresponding blue light emission. The light-emitting unit is, for example, a micro-light-emitting diode, with a size of 0.1–100 micrometers. The substrate can be a complementary metal-oxide-semiconductor (CMOS) driving substrate, a thin-film transistor (TFT) driving substrate, or a liquid crystal on silicon (LCOS) driving substrate.

[0092] In one embodiment, the present invention also provides a method for fabricating a quantum dot light-emitting device as described above, the method comprising the following steps:

[0093] A passivation layer is formed on the substrate;

[0094] The first mixed solution obtained in step S3 above is uniformly spin-coated onto the passivation layer;

[0095] Performing steps S4, S5, and S6 on the first mixed solution spin-coated onto the passivation layer yields a first-color quantum dot aerogel composite material; and

[0096] The first color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film layer in a first region of the substrate.

[0097] Furthermore, the method for fabricating the quantum dot light-emitting device also includes:

[0098] The second mixed solution obtained in step S3 above is uniformly spin-coated onto the passivation layer;

[0099] Performing steps S4, S5, and S6 on the second mixed solution yields a second-color quantum dot aerogel composite material; and

[0100] The second color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a second color quantum dot aerogel composite material film layer in the second region of the substrate, and the first region and the second region do not overlap.

[0101] Specifically, the step of "performing steps S4, S5, and S6 on the first mixed solution spin-coated onto the passivation layer to obtain a first-color quantum dot aerogel composite film" involves: placing the substrate spin-coated with the first mixed solution in the dark at room temperature for several hours to a day to allow it to form a gel; then, aging and solvent replacement are performed on the first gel on the substrate, with the aging time controlled at 1 to 3 days; after the aging treatment, water and residual silica precursor in the gel are repeatedly replaced with anhydrous ethanol or other organic solvents (e.g., n-hexane); and finally, the gel after the aging treatment is subjected to supercritical drying, with the critical conditions for supercritical drying being: a temperature of approximately 40°C, a pressure of 7-10 MPa, and carbon dioxide as the drying medium, to obtain the first-color quantum dot aerogel composite material.

[0102] Furthermore, the first color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film layer in a first region of the substrate. This first color quantum dot aerogel composite material film layer covers the light-emitting surface of the light-emitting unit, and the light energy emitted by the light-emitting unit is converted into light of the corresponding color by the first color quantum dot aerogel composite material film layer and emitted. The etching process described above can be a dry etching process or a wet etching process.

[0103] The aforementioned passivation layer can be, for example, an inorganic encapsulation layer, which covers the light-emitting element to provide protection and prevent corrosion or other damage to the light-emitting element during subsequent operations. Optionally, the passivation layer is an alumina passivation layer. Optionally, the inorganic encapsulation layer is applied to the light-emitting element using atomic layer deposition (ALD) or inductively coupled plasma-enhanced chemical vapor deposition (ICPCVD).

[0104] Following the above method, a third-color quantum dot aerogel composite material film can also be formed in a third region of the substrate, wherein the third region does not overlap with the first region or the first region. Furthermore, the formed third-color quantum dot aerogel composite material film covers the light-emitting surface of the light-emitting unit, and the light energy emitted by the light-emitting unit is converted into light of the corresponding color by the third-color quantum dot aerogel composite material film.

[0105] In another embodiment, the present invention also provides a method for fabricating a quantum dot light-emitting device as described above, the method comprising the following steps:

[0106] A passivation layer is formed on the substrate;

[0107] The first mixed solution obtained in step S3 above is uniformly spin-coated onto the passivation layer;

[0108] Perform step S4 above on the first mixed solution spin-coated onto the passivation layer;

[0109] After mixing and stirring the first gel obtained in step S4 with the photoresist until homogeneous, steps S5 and S6 are performed to obtain a first-color quantum dot aerogel composite material mixed with photoresist; and

[0110] The first-color quantum dot aerogel composite material mixed with photoresist is patterned using an exposure and development process or an etching process to form a first-color quantum dot aerogel composite material film layer mixed with photoresist in a first region of the substrate. Furthermore, the formed first-color quantum dot aerogel composite material film layer mixed with photoresist covers the light-emitting surface of the light-emitting unit, and the light energy emitted by the light-emitting unit is converted into light of the corresponding color by the first-color quantum dot aerogel composite material film layer mixed with photoresist and emitted.

[0111] Furthermore, the preparation method further includes the following steps:

[0112] The second mixed solution obtained in step S3 above is uniformly spin-coated onto the passivation layer;

[0113] Perform step S4 above on the second mixed solution;

[0114] After mixing and stirring the second gel obtained in step S4 with the photoresist until homogeneous, steps S5 and S6 are performed to obtain a second-color quantum dot aerogel composite material mixed with photoresist; and

[0115] The second-color quantum dot aerogel mixed with photoresist is patterned using an exposure and development process or an etching process to form a second-color quantum dot aerogel composite material film mixed with photoresist in a second region of the substrate. The first region and the second region do not overlap. Moreover, the formed second-color quantum dot aerogel composite material film mixed with photoresist covers the light-emitting surface of the light-emitting unit, and the light energy emitted by the light-emitting unit is converted into light of the corresponding color by the second-color quantum dot aerogel composite material film mixed with photoresist and emitted.

[0116] Following the above method, a third-color quantum dot aerogel composite material film mixed with photoresist can also be formed in a third region of the substrate, wherein the third region does not overlap with the first region or the first region. Furthermore, the formed third-color quantum dot aerogel composite material film mixed with photoresist covers the light-emitting surface of the light-emitting unit, and the light energy emitted by the light-emitting unit is converted into light of the corresponding color by the third-color quantum dot aerogel composite material film mixed with photoresist and emitted.

[0117] The aforementioned photoresist includes, for example, an adhesive, a photosensitizer, a functional monomer, a solvent, and additives. The adhesive is, for example, an acrylic resin, which may include, for example, one or more of isobutyl acrylate, isobornyl methacrylate, or isodecyl acrylate. However, the present invention is not limited thereto. In a preferred embodiment, the additives include one or more of adhesion promoters, coupling agents, dispersants, diluents, or defoamers. Specifically, additives can be added according to actual production conditions to improve the stability of the finished product. In a preferred embodiment, the functional monomer is an acrylic monomer. For example, the adhesive can be an acrylic resin, the functional monomer can be an acrylic monomer, the photosensitizer can be a benzophenone-based photosensitizer, the solvent can be propylene glycol methyl ether acetate (PGMEA) solvent, and the additive can be a diluent, which can reduce the viscosity of the solution.

[0118] The present invention will be further described below with reference to specific embodiments.

[0119] Example 1

[0120] The preparation method of the quantum dot aerogel composite material provided in this embodiment is as follows:

[0121] (1) Cd-based red quantum dots are dispersed in ethanol solvent, and weakly adsorbed substances on the surface of the quantum dots are removed by centrifugation to form a Cd-based red quantum dot solution; 3-aminopropyltriethoxysilane (APTES) is dissolved in anhydrous ethanol, and a small amount of water is added. The mixture is stirred for 30 minutes or more to partially hydrolyze APTES to generate silanol groups (-SiOH) to form an APTES solution; the Cd-based red quantum dot solution is added to the APTES solution, and the mixture is stirred at 60°C for 12-24 hours under nitrogen protection to prevent silane polymerization, thereby obtaining a reaction solution; the reaction solution is separated by centrifugation, and the reaction solution is washed with anhydrous ethanol and isopropanol, respectively, to remove silane coupling agents that are not bound to the surface of the quantum dots; the reaction solution is dried in a vacuum drying oven to form modified quantum dots with silanol groups on the surface. In this embodiment, the mass percentage concentration of the modified quantum dots is 30%.

[0122] (2) Mix tetraethoxysilane and anhydrous ethanol at a volume ratio of 1:4 and stir until homogeneous. Then slowly add deionized water and catalyst (molar concentration of 0.01 mol / L). The molar ratio of deionized water to the silica precursor is 1:4. Stir at room temperature for 1 hour to form a uniform and transparent silica sol.

[0123] (3) Disperse the modified quantum dots from step (1) in a small amount of ethanol, use ultrasonic oscillation to ensure uniform dispersion, and then slowly add them to the silica sol obtained in step (2), and stir or ultrasonically oscillate for more than 30 minutes to ensure that the modified quantum dots are uniformly dispersed in the silica sol to form a mixed solution.

[0124] (4) Place the mixed solution obtained in step (3) in a sealed container and let it stand for 10 hours to form a gel. The gel formed is uniform and transparent and has no obvious agglomeration.

[0125] (5) The gel obtained in step (4) is placed in anhydrous ethanol for aging treatment for 1 day to enhance the strength of the network structure, and the water and residual silica precursor in the gel are replaced multiple times with anhydrous ethanol or n-hexane.

[0126] (6) The gel after aging in step (5) is subjected to supercritical drying. The critical conditions are: temperature about 40°C, pressure 7-10 MPa, and drying medium such as carbon dioxide, to obtain quantum dot aerogel composite material.

[0127] Example 2

[0128] Based on Example 1, the Cd-based red quantum dots in Example 1 were replaced with Cd-based green quantum dots.

[0129] Example 3

[0130] Based on Example 1, the Cd-based red quantum dots in Example 1 were replaced with perovskite red quantum dots for the experiment.

[0131] Example 4

[0132] Based on Example 1, the Cd-based red quantum dots in Example 1 were replaced with perovskite green quantum dots for the experiment.

[0133] Example 5

[0134] (1) Cd-based red quantum dots were dispersed in ethanol solvent, and weakly adsorbed substances on the surface of the quantum dots were removed by centrifugation to form a Cd-based red quantum dot solution; 3-aminopropyltriethoxysilane (APTES) was dissolved in anhydrous ethanol, and a small amount of water was added. The mixture was stirred for 30 minutes to partially hydrolyze APTES to generate silanol groups (-SiOH) to form an APTES solution; the Cd-based red quantum dot solution was added to the APTES solution, and the mixture was stirred at 60°C for 2 hours to make the surface of the Cd-based red quantum dots have silanol groups and expose dynamic bond groups. Nitrogen gas was used to protect the solution from silane polymerization to obtain a reaction solution; the reaction solution was separated by centrifugation and washed with anhydrous ethanol and isopropanol to remove silane coupling agents that were not bound to the surface of the quantum dots; the reaction solution was dried in a vacuum drying oven to form modified quantum dots. In this embodiment, the mass percentage concentration of the modified quantum dots was 50%.

[0135] (2) Tetraethoxysilane and anhydrous ethanol are mixed in a volume ratio of 1:4 and stirred until homogeneous. Then, deionized water and catalyst (molar concentration of 0.01 mol / L) are slowly added. The molar ratio of deionized water to the silica precursor is 1:4. The mixture is stirred at room temperature for 1 hour to form a uniform and transparent silica sol. A dynamic bond auxiliary reagent phenylboronic acid solution (mass percentage concentration of 1%) is added to the silica sol and stirred until homogeneous, so that the silica network has dynamic response characteristics.

[0136] (3) Disperse the modified quantum dots from step (1) in a small amount of ethanol, use ultrasonic oscillation to ensure uniform dispersion, and then slowly add them to the silica sol obtained in step (2), and stir or ultrasonically oscillate for more than 30 minutes to ensure that the modified quantum dots are uniformly dispersed in the silica sol. The modified quantum dots and the silica sol undergo a dynamic cross-linking reaction to form a mixed solution with a dynamic network.

[0137] (4) Place the mixed solution obtained in step (3) in a sealed container and let it stand for 10 hours to form a gel. The gel formed is uniform and transparent and has no obvious agglomeration.

[0138] (5) The gel obtained in step (4) is placed in anhydrous ethanol for aging treatment for 1 day to enhance the strength of the network structure, and the water and residual silica precursor in the gel are replaced multiple times with anhydrous ethanol or n-hexane.

[0139] (6) The gel after aging in step (5) is subjected to supercritical drying. The critical conditions are: temperature about 40°C, pressure 7-10 MPa, and drying medium such as carbon dioxide, to obtain quantum dot aerogel composite material.

[0140] Comparative Example 1

[0141] Traditional quantum dot aerogels (using Cd red quantum dots) were prepared using the conventional quantum dot-filled aerogel method.

[0142] Comparative Example 2

[0143] No aerogel is formed; only a quantum dot film is created (using Cd green quantum dots).

[0144] Please refer to Table 1 below, which shows the aging test results of the examples and comparative examples.

[0145] Table 1

[0146]

[0147] Based on the above embodiments and comparative examples, it can be clearly concluded that, compared with traditional quantum dot films and traditional quantum dot aerogels, the quantum dot aerogel composite material layer in Embodiments 1-5 of the present invention exhibits a significantly longer lifespan, creating application conditions for operation in harsh environments. Additionally, please refer to... Figure 2 , Figure 2 The image shows a SEM image of the quantum dot aerogel film in Example 1 of this invention. As can be seen from the image, the pores are uniform and the quantum dots are well bonded to the aerogel, which helps to improve the luminescence efficiency and stability of the quantum dots.

[0148] In summary, this invention uniformly disperses modified quantum dots in silica sol, allowing them to covalently or physically bond with the silica network during gelation, or form a dynamic network, thereby creating a highly stable quantum dot aerogel composite material. Furthermore, the modified quantum dots enhance the compatibility between the quantum dots and the silica network, forming robust bonds. In addition, supercritical drying can form a composite material with an aerogel framework encapsulating the quantum dots, avoiding capillary action and preserving the photoelectric properties of the quantum dots and the high porosity of the aerogel. Moreover, the porous quantum dot aerogel composite material obtained by this invention perfectly combines the luminescent properties of quantum dots and the thermal insulation properties of aerogel, significantly improving the high-temperature resistance and blue light resistance of the quantum dot aerogel composite film. Furthermore, the preparation method of this invention is simple and can be applied to display devices of different sizes (especially small sizes), greatly expanding the application range of quantum dots.

[0149] Therefore, the present invention has been described by the above-described related embodiments; however, the above embodiments are merely examples for implementing the present invention. Furthermore, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A method for preparing a quantum dot aerogel composite material, characterized in that, The preparation method of the quantum dot aerogel composite material includes: Step S1: Add a silane coupling agent to the quantum dots and perform surface modification treatment on the quantum dots to form modified quantum dots with silanol groups on the surface. Step S2: Mix the silica precursor and anhydrous ethanol in a set ratio and stir until homogeneous. Then slowly add deionized water and catalyst and stir at room temperature to form a uniform and transparent silica sol. Step S3: Slowly add the uniformly dispersed modified quantum dots into the silica sol, and stir or sonicate to ensure that the modified quantum dots are uniformly dispersed in the silica sol to form a mixed solution; Step S4: Place the mixed solution in a sealed container and let it stand for a first specific time to form a gel; Step S5: The gel is placed in anhydrous ethanol for a second specific time for aging treatment, and the water and residual silica precursor in the gel are replaced multiple times with anhydrous ethanol or n-hexane. Step S6: The aged gel is subjected to supercritical drying to obtain a quantum dot aerogel composite material.

2. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, Step S1 includes: Step S11: Disperse the quantum dots in hexane or ethanol solvent, and remove the weakly adsorbed substances on the surface of the quantum dots by centrifugation to obtain a quantum dot solution. Step S12: Dissolve the silane coupling agent in anhydrous ethanol, add a small amount of water, and stir to partially hydrolyze the silane coupling agent to generate silanol groups, thereby obtaining a silane coupling agent solution. Step S13: Add the quantum dot solution to the silane coupling agent solution, stir at 60°C for 12-24 hours, and protect with nitrogen to prevent silane polymerization to obtain a reaction solution; Step S14: Centrifuge the reaction solution, wash the reaction solution with anhydrous ethanol and isopropanol respectively to remove silane coupling agent that is not bound to the surface of the quantum dots; and dry the reaction solution in a vacuum drying oven to obtain the modified quantum dots with silanol groups on the surface.

3. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, In step S2, the volume ratio of the silica precursor to the anhydrous ethanol is 1:4, the molar ratio of the deionized water to the silica precursor is 1:4, and the molar concentration of the catalyst is 0.01 mol / L.

4. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, The mass percentage concentration of the modified quantum dots is 0.01%~0.1%.

5. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, The quantum dots are selected from one or a mixture of several of CdSe / ZnS quantum dots, CdTe quantum dots, PbS quantum dots, carbon quantum dots, and perovskite quantum dots.

6. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, The silane coupling agent is selected from at least one of 3-aminopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane.

7. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, The silica precursor is tetraethoxysilane, and the catalyst is a dilute acid or a dilute alkali.

8. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, The critical conditions for the supercritical drying process are: a temperature of 40°C, a pressure of 7-10 MPa, and a drying medium of carbon dioxide or nitrogen.

9. The method for preparing the quantum dot aerogel composite material as described in claim 1, characterized in that, Step S1 further includes: stirring the mixture of quantum dots and silane coupling agent for more than 2 hours, so that the surface of the modified quantum dots has silanol groups and exposes dynamic bond groups; Step S2 further includes: adding dynamic bond auxiliary reagent to the silica sol and stirring evenly, so that the silica sol has dynamic response characteristics; In Step S3, the modified quantum dots and the silica sol undergo a dynamic crosslinking reaction to form a mixed solution with a dynamic network.

10. The method for preparing the quantum dot aerogel composite material as described in claim 9, characterized in that, The dynamic bond auxiliary reagent is selected from phenylboronic acid solution, o-dialdehyde solution, and solution containing metal ions Fe³⁺ or Zn²⁺.

11. A quantum dot aerogel composite material, characterized in that, The quantum dot aerogel composite material is prepared using the preparation method described in any one of claims 1-10.

12. A quantum dot light-emitting device, comprising a substrate and a quantum dot aerogel composite material film layer disposed in conjunction with the substrate, the substrate comprising light-emitting units arranged in an array, the quantum dot aerogel composite material film layer being formed on the substrate such that the light-emitting surface of the light-emitting units is covered by the quantum dot aerogel composite material film layer, characterized in that, The quantum dot aerogel composite material film is formed by forming the quantum dot aerogel composite material as described in claim 11 on the substrate and then performing an exposure and development process or an etching process.

13. A method for fabricating a quantum dot light-emitting device as described in claim 12, characterized in that, The method for fabricating the quantum dot light-emitting device includes the following steps: A passivation layer is formed on the substrate; The first mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer; Steps S4, S5 and S6 are performed on the first mixed solution spin-coated onto the passivation layer to obtain the first color quantum dot aerogel composite material. The first color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film layer in a first region of the substrate.

14. The method for fabricating a quantum dot light-emitting device as described in claim 13, characterized in that, The preparation method further includes: The second mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer; Steps S4, S5 and S6 are performed on the second mixed solution to obtain a second color quantum dot aerogel composite material. The second color quantum dot aerogel composite material is patterned using an exposure and development process or an etching process to form a second color quantum dot aerogel composite material film layer in the second region of the substrate, and the first region and the second region do not overlap.

15. A method for fabricating a quantum dot light-emitting device as described in claim 12, characterized in that, The method for fabricating the quantum dot light-emitting device includes the following steps: A passivation layer is formed on the substrate; The first mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer; Step S4 is performed on the first mixed solution spin-coated onto the passivation layer; After mixing and stirring the first gel obtained in step S4 with the photoresist, continue to execute steps S5 and S6 to obtain a first color quantum dot aerogel composite material mixed with photoresist. The first color quantum dot aerogel composite material mixed with photoresist is patterned by an exposure and development process or an etching process to form a first color quantum dot aerogel composite material film mixed with photoresist in a first region of the substrate.

16. The method for fabricating a quantum dot light-emitting device as described in claim 15, characterized in that, The preparation method further includes: The second mixed solution obtained in step S3 is uniformly spin-coated onto the passivation layer; Step S4 is performed on the second mixed solution; After mixing and stirring the second gel obtained in step S4 with the photoresist, continue to execute steps S5 and S6 to obtain a second color quantum dot aerogel composite material mixed with photoresist. The second color quantum dot aerogel composite material mixed with photoresist is patterned using an exposure and development process or an etching process to form a second color quantum dot aerogel composite material film mixed with photoresist in the second region of the substrate, wherein the first region and the second region do not overlap.

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