Composite materials, methods of making and using the same

Abstract

This application discloses a composite material, its preparation method, and its application. The composite material includes fluorescent organic nanomaterials and an ionic surfactant, with the ionic surfactant attached to the surface of the fluorescent organic nanomaterials. When the composite material is in a solution system, the surfactant ionizes, allowing the surface of the composite material to carry a charge. This material can be stably dispersed in the solvent due to its electrostatic repulsion and can also be deposited into a film under an electric field. This method not only offers fast film formation and high production efficiency but also produces excellent film with good photoelectric properties. When this film is used in a display panel, it helps improve the panel's resolution. Furthermore, this deposition method has relatively low solvent requirements, making it suitable for a wider range of applications.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a composite material, its preparation method, and its application. Background Technology

[0002] The efficient conversion of light from short wavelengths to long wavelengths using color conversion layers (CCLs) is fundamental to the successful operation of many contemporary display and lighting technologies. Currently, inorganic quantum dot luminescent materials and fluorescent organic nanomaterials are commonly used as materials for preparing color conversion layers. However, inorganic quantum dots are highly sensitive to water, oxygen, and temperature, exhibiting low stability, and their synthesis process involves toxic heavy metals, resulting in poor environmental friendliness. Therefore, fluorescent organic nanomaterials are more widely used in practical production.

[0003] Due to their structural characteristics, most current methods for preparing color conversion layers using fluorescent organic nanomaterials employ inkjet printing. However, this method suffers from low resolution, long processing time, and high requirements for the solvent system of the printing ink. These drawbacks severely restrict the development of patterning fluorescent organic nanomaterials and limit their application in display panels. Summary of the Invention

[0004] In view of this, this application provides a composite material, its preparation method and application, and aims to provide an organic composite material that can be film-formed by electrodeposition.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, this application provides a composite material comprising fluorescent organic nanomaterials and an ionic surfactant, wherein the ionic surfactant is attached to the surface of the fluorescent organic nanomaterials.

[0007] Optionally, in some embodiments of this application, the mass ratio of the ionic surfactant to the fluorescent organic nanomaterial in the composite material is 10–50:100.

[0008] Optionally, in some embodiments of this application, the average particle size of the composite material is 10–200 nm; and / or,

[0009] The fluorescent organic nanomaterials include coumarin derivatives, rhodamine and its derivatives, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole, 1,2,3,5-tetra(carbazole-9-yl)-4,6-dicyanophenylene, 2,4,5,6-tetra(9H-carbazole-9-yl)isophthalonitrile, 1,3,7, One or more of the following: 9-tetra(4-(tert-butyl)phenyl)-5,5-difluoro-10-(2-methoxyphenyl)-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaniline; and 2,12-di-tert-butyl-N,N,5,9-tetra(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaz-13b-boraz[3,2,1-de]anthracene-7-amine; and / or

[0010] The ionic surfactants include one or more of the following: tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, hexadecyltrimethylammonium bromide, imidazoline ammonium salt surfactants, carboxylate surfactants, sulfonate surfactants, sulfate ester surfactants, and phosphonate ester surfactants.

[0011] Secondly, this application also proposes a method for preparing a composite material, comprising the following steps:

[0012] A first solution is provided, the first solution containing fluorescent organic nanomaterials and ionic surfactants;

[0013] Provides a poor solvent for the fluorescent organic nanomaterials;

[0014] The unsuitable solvent and the first solution are mixed, and then solid-liquid separation is performed to obtain a composite material. The composite material includes fluorescent organic nanomaterials and ionic surfactants, and the ionic surfactants are attached to the surface of the fluorescent organic nanomaterials.

[0015] Optionally, in some embodiments of this application, the undesirable solvent includes a polar solvent, such as methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, or water; and / or,

[0016] The mass ratio of the ionic surfactant to the fluorescent organic nanomaterial is 10–50:100; and / or,

[0017] The first solution further includes a nonpolar solvent, which includes one or more of tetrahydrofuran, toluene, chlorobenzene, chloroform, and octane; and / or,

[0018] The fluorescent organic nanomaterials include coumarin derivatives, rhodamine and its derivatives, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole, 1,2,3,5-tetra(carbazole-9-yl)-4,6-dicyanophenylene, 2,4,5,6-tetra(9H-carbazole-9-yl)isophthalonitrile, 1,3,7, One or more of the following: 9-tetra(4-(tert-butyl)phenyl)-5,5-difluoro-10-(2-methoxyphenyl)-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaniline; and 2,12-di-tert-butyl-N,N,5,9-tetra(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaz-13b-boraz[3,2,1-de]anthracene-7-amine; and / or

[0019] The ionic surfactants include one or more of the following: tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, hexadecyltrimethylammonium bromide, imidazoline ammonium salt surfactants, carboxylate surfactants, sulfonate surfactants, sulfate ester surfactants, and phosphonate ester surfactants.

[0020] Thirdly, this application also proposes a thin film, the material of which includes the composite material described above, or the composite material prepared by the preparation method described above.

[0021] Fourthly, this application proposes a method for preparing a thin film, comprising the following steps:

[0022] A mixed solution is provided, the mixed solution comprising a polar solvent and a composite material, the composite material comprising the composite material described above, or comprising a composite material prepared by the preparation method described above;

[0023] A thin film is obtained by depositing the composite material in the mixed solution through electrodeposition.

[0024] Optionally, in some embodiments of this application, the polar solvent includes one or more of methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, and water; and / or,

[0025] In the mixed solution, the concentration of the composite material is 10–100 mg / ml.

[0026] Optionally, in some embodiments of this application, the step of depositing the mixed solution to obtain a thin film by electrodeposition includes:

[0027] A substrate is provided, the substrate including an electrode layer;

[0028] The mixed solution is brought into contact with the substrate, and then a voltage is applied to the electrode layer to form an electric field, driving the composite material to deposit on the electrode layer to form a thin film.

[0029] Optionally, in some embodiments of this application, the voltage is greater than 0V and less than or equal to 300V; and / or,

[0030] The electric field strength is 0.01–10 V / μm.

[0031] Optionally, in some embodiments of this application, the step of contacting the mixed solution with the substrate includes:

[0032] Place the substrate in the mixed solution; or...

[0033] The mixed solution is dropped onto the substrate.

[0034] Fifthly, this application also proposes a display panel, including a first electrode layer, a second electrode layer, and a light-emitting layer disposed between the first electrode layer and the second electrode layer, wherein the light-emitting layer includes the thin film described above, or includes a thin film prepared by the preparation method described above.

[0035] Sixthly, this application also proposes a display device, including a display panel as described above.

[0036] In the technical solution provided in this application, ionic surfactants are adsorbed on the surface of fluorescent organic nanomaterials. When the composite material is in a solution system, the surfactants ionize, thereby enabling the surface of the composite material to carry charges. Such materials can be stably dispersed in the solvent due to their electrostatic repulsion and can also be deposited into films under the action of an electric field. This not only results in fast film formation and high production efficiency, but also good film formation effect and good photoelectric properties. When this film is used in a display panel, it helps to improve the resolution of the panel. In addition, this deposition method has relatively low requirements for solvents and can be applied to more application scenarios. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic flowchart of a method for preparing a composite material according to an embodiment of this application;

[0039] Figure 2This is a schematic flowchart of a thin film preparation method according to an embodiment of this application;

[0040] Figure 3 yes Figure 2 A flowchart illustrating step S200 in the illustrated embodiment;

[0041] Figure 4 This is a schematic flowchart of a thin film preparation method according to another embodiment of this application;

[0042] Figure 5 This is a schematic flowchart of a method for preparing a thin film according to another embodiment of this application;

[0043] Figure 6 This is a schematic diagram of the manufacturing process of the display panel proposed in the application embodiment;

[0044] Figure 7 This is a photograph of the thin film prepared in Example 1 emitting light after being excited by ultraviolet light;

[0045] Figure 8 This is a photograph of the thin film obtained in Example 2 emitting light after being excited by ultraviolet light;

[0046] Figure 9 This is a photograph of the thin film obtained in Example 3 emitting light after being excited by ultraviolet light;

[0047] Figure 10 This is a photograph of a red and green dual-color conversion array obtained according to an embodiment of this application emitting light after being excited by ultraviolet light;

[0048] Figure label:

[0049] 10 - Substrate; 20 - First electrode layer; 30 - Composite material; 40 - Red pixel unit; 50 - Green pixel unit. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0051] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0055] Furthermore, various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0056] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0057] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0058] In a first aspect, embodiments of this application provide a composite material 30, the composite material 30 comprising fluorescent organic nanomaterials and ionic surfactants, the ionic surfactants being attached to the surface of the fluorescent organic nanomaterials.

[0059] In the technical solution provided in this application, ionic surfactants are adsorbed on the surface of fluorescent organic nanomaterials. When the composite material 30 is in a solution system, the surfactants ionize in the solvent, thereby enabling the surface of the composite material 30 to carry charges. Such materials can be stably dispersed in the solvent due to their electrostatic repulsion and can also be deposited into films under the action of an electric field. This not only results in fast film formation and high production efficiency, but also good film formation effect and good photoelectric properties. When this film is used in a display panel, it helps to improve the resolution of the panel. In addition, this deposition method has relatively low requirements for solvents and can be applied to more application scenarios.

[0060] In some embodiments, the mass ratio of the ionic surfactant to the fluorescent organic nanomaterial in the composite material 30 is 10 to 50:100; for example, it can be 10:100, 20:100, 30:100, 40:100, 50:100, or any two of the above values. Within this range, it helps to improve the surface charge and dispersibility of the material while avoiding affecting the luminescence performance of the material.

[0061] In some embodiments, the average particle size of the composite material 30 is 10–200 nm; for example, 10–50 nm, 30–70 nm, 60–100 nm, 80–130 nm, 110–150 nm, 130–180 nm, 160–200 nm, etc.; specific examples can be 10 nm, 20 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 170 nm, 200 nm, and values ​​between any two of the above.

[0062] In some embodiments, the fluorescent organic nanomaterial refers to an organic material that can emit light of different wavelengths after absorbing light of a certain wavelength, and its size is at the nanometer scale. The fluorescent organic nanomaterial can be a fluorescent luminescent organic material commonly used in the art, such as, but not limited to, coumarin derivatives, rhodamine and its derivatives, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole (also known as Ttrz-DI), 2,3,5,6-tetra(carbazole-9-yl)-1,4-dicyanophenyl (also known as 4CzTPN), 3,4,5,6-tetra(9-carbazole)-phthalonitrile (also known as 4CzPN), 1,2,3,5-tetra(carbazole-9-yl)-4 One or more of the following: 6-dicyanophenylene, 2,4,5,6-tetrakis(9H-carbazole-9-yl)isophthalonitrile (also known as 4CzIPN), 1,3,7,9-tetrakis(4-(tert-butyl)phenyl)-5,5-difluoro-10-(2-methoxyphenyl)-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaaniline (also known as 4tBuMB), and 2,12-di-tert-butyl-N,N,5,9-tetrakis(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaza-13b-boraza[3,2,1-de]anthracene-7-amine (also known as CzDABNA). For example, Ttrz-DI can emit green light, 4tBuMB can emit red light, and CzDABNA can emit blue light.

[0063] In some embodiments, the ionic surfactant includes cationic surfactants and anionic surfactants. The cationic surfactant may include, but is not limited to, one or more of tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, hexadecyltrimethylammonium bromide, and imidazoline ammonium salts; the anionic surfactant may include, but is not limited to, one or more of carboxylate surfactants (e.g., potassium, sodium, or ammonium salts of higher fatty acids, and triethanolamine salts), sulfonate surfactants (e.g., sodium dioctyl succinate sulfonate, calcium dodecylbenzene sulfonate, and sodium dodecylbenzene sulfonate), sulfate ester surfactants (e.g., sodium dodecyl sulfate, sodium lauryl sulfate, etc.), and phosphonate ester surfactants.

[0064] Secondly, this application also proposes a method for preparing composite material 30, please refer to [link to relevant documentation]. Figure 1 This includes the following steps:

[0065] S10, providing a first solution, the first solution containing fluorescent organic nanomaterials and ionic surfactants;

[0066] S20 provides a poor solvent for the fluorescent organic nanomaterial;

[0067] S30, the unsuitable solvent and the first solution are mixed, and then solid-liquid separation is performed to obtain composite material 30. The composite material 30 comprises fluorescent organic nanomaterials and an ionic surfactant, the ionic surfactant being attached to the surface of the fluorescent organic nanomaterials.

[0068] In step S10, the fluorescent organic nanomaterial may include, but is not limited to, coumarin derivatives, rhodamine and its derivatives, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole (also known as Ttrz-DI), 2,3,5,6-tetra(carbazol-9-yl)-1,4-dicyanophenylene (also known as 4CzTPN), 3,4,5,6-tetra(9-carbazolyl)-phthalonitrile (also known as 4CzPN), and 1,2,3,5-tetra(carbazol-9-yl)-4,6-dicyanophenylene. One or more of the following: 2,4,5,6-tetrakis(9H-carbazole-9-yl)isophthalonitrile (also known as 4CzIPN), 1,3,7,9-tetrakis(4-(tert-butyl)phenyl)-5,5-difluoro-10-(2-methoxyphenyl)-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaaniline (also known as 4tBuMB), and 2,12-di-tert-butyl-N,N,5,9-tetrakis(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaza-13b-boraza[3,2,1-de]anthracene-7-amine (also known as CzDABNA).

[0069] The ionic surfactants include cationic surfactants and anionic surfactants. The cationic surfactants may include, but are not limited to, one or more of tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, hexadecyltrimethylammonium bromide, and imidazoline ammonium salts. The anionic surfactants may include, but are not limited to, one or more of carboxylate surfactants (e.g., potassium, sodium, or ammonium salts of higher fatty acids, and triethanolamine salts), sulfonate surfactants (e.g., sodium dioctyl succinate sulfonate, calcium dodecylbenzene sulfonate, and sodium dodecylbenzene sulfonate), sulfate ester surfactants (e.g., sodium dodecyl sulfate, sodium lauryl sulfate, etc.), and phosphonate ester surfactants.

[0070] In some embodiments, the first solution further includes a nonpolar solvent, which includes one or more of tetrahydrofuran, toluene, chlorobenzene, chloroform, and octane.

[0071] In some embodiments, the concentration of the fluorescent organic nanomaterial in the first solution can be 50 to 1000 mg / ml, for example, 50 mg / ml, 100 mg / ml, 150 mg / ml, 200 mg / ml, 300 mg / ml, 500 mg / ml, 700 mg / ml, 800 mg / ml, 1000 mg / ml, and any value between any two of the above.

[0072] The amount of the ionic surfactant added can be adjusted according to the mass of the fluorescent organic nanomaterial. In some embodiments, the mass ratio of the ionic surfactant to the fluorescent organic nanomaterial is 10 to 50:100; for example, it can be 10:100, 20:100, 30:100, 40:100, 50:100, or any two of the above values.

[0073] In some embodiments, in step S20, the undesirable solvent includes a polar solvent, which includes one or more of methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, and water.

[0074] By adding a poor solvent, the solubility of the fluorescent organic nanomaterials in the solution system is reduced, causing them to precipitate with the ionic surfactants adsorbed on their surface and aggregate into nanoparticles, thus obtaining composite material 30. The average particle size of the composite material 30 is 10–200 nm; for example, 10–50 nm, 30–70 nm, 60–100 nm, 80–130 nm, 110–150 nm, 130–180 nm, 160–200 nm, etc.

[0075] Thirdly, this application also proposes a thin film, the material of which includes the composite material 30 as described above, or the composite material 30 prepared as described above. When the thin film is prepared using the above-mentioned composite material 30, it can be prepared by electrodeposition. In this way, the prepared thin film has good film-forming effect and good photoelectric properties. When the thin film is used in a display panel, it helps to improve the resolution of the panel.

[0076] Fourthly, this application also proposes a method for preparing a thin film; please refer to [link to relevant documentation]. Figure 2 The preparation method includes the following steps:

[0077] S100, providing a mixed solution comprising a polar solvent and a composite material, the composite material comprising composite material 30 as described above, or comprising composite material 30 prepared by the preparation method described above;

[0078] S200, a thin film is obtained by electrodeposition of the composite material in the mixed solution.

[0079] When composite material 30 is in a solution environment, the surfactant ionizes, causing the material surface to become charged. Under the influence of an electric field, the charged material can migrate to an electrode with the opposite charge to deposit as a film. Moreover, due to the charge neutralization mechanism, the surface charge of the material is neutralized on the electrode surface, making it unable to be stably dispersed in the solvent and thus unable to be dispersed by the solvent again, resulting in stable film deposition and good film formation. This film-forming method not only has a fast film-forming speed (the time for composite material 30 to deposit on the electrode to form a thin film after applying an electric field is often no more than 10 seconds) and high production efficiency, but also has a good film-forming effect with good photoelectric properties. When this film is used in a display panel, it helps to improve the resolution of the panel. In addition, this deposition method has relatively low requirements for solvents and can be applied to more application scenarios.

[0080] In some embodiments, the polar solvent includes one or more of methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, and water; the polar solvent facilitates the stable dispersion of the composite material 30 and provides a suitable ionization environment for the surfactant.

[0081] In some embodiments, the concentration of the composite material 30 in the mixed solution is 10 to 100 mg / ml, for example, it can be 10 mg / ml, 15 mg / ml, 20 mg / ml, 30 mg / ml, 50 mg / ml, 70 mg / ml, 80 mg / ml, 100 mg / ml, or any value between any two of the above.

[0082] In some embodiments, step S200 may be implemented as follows:

[0083] S201, a substrate 10 is provided, the substrate 10 including an electrode layer;

[0084] S202, the mixed solution is brought into contact with the substrate 10, and then a voltage is applied to the electrode layer to form an electric field, driving the composite material 30 to be deposited on the electrode layer to form a thin film.

[0085] Please see Figure 3 When the mixed solution is brought into contact with the substrate 10 having the electrode layer, under the action of the electric field, the charged composite material 30 moves onto the electrode layer and is stably deposited to form a patterned thin film with the same shape as the electrode.

[0086] In some embodiments, the electric field may be a direct current electric field.

[0087] In some embodiments, the voltage is 0V to 300V; for example, it can be 0V to 10V, 5V to 20V, 15V to 50V, 5V to 100V, 60V to 200V, 180V to 250V, 150V to 300V, etc.

[0088] In some embodiments, the electric field strength is 0.01 to 10 V / μm, for example, it can be 0.01 to 1 V / μm, 0.1 to 5 V / μm, 0.5 to 3 V / μm, 2 to 5 V / μm, 4 to 8 V / μm, 7 to 10 V / μm, etc.

[0089] Furthermore, in practice, step S202 can be implemented in various ways. Please refer to [link / reference]. Figure 4 In some embodiments, step S202 specifically includes: S202a, placing the substrate 10 in the mixed solution, and then applying a voltage to the electrode layer to form an electric field, driving the composite material 30 to deposit on the side of the electrode layer away from the substrate, forming a thin film. That is, inserting the substrate 10 into the mixed solution, and then applying a voltage to the electrode layer to form an electric field, driving the composite material 30 to deposit on the side of the electrode layer away from the substrate, forming a thin film; see [link to previous section]. Figure 5 In another embodiment, step S202 specifically includes: S202b, adding the mixed solution dropwise onto the substrate 10, and then applying a voltage to the electrode layer to form an electric field, driving the composite material 30 to deposit on the side of the electrode layer away from the substrate to form a thin film.

[0090] Fifthly, this application also proposes a display panel, which can be a display panel in any display device. The display panel may include the thin film described above, or a thin film prepared by the preparation method described above.

[0091] In some embodiments, the thin film can be a light-emitting layer of a display panel; for example, the display panel may include a first electrode layer 20, a light-emitting layer, and a second electrode layer stacked sequentially. Specifically, as shown... Figure 6 As shown, the display panel may include a substrate 10, a first electrode layer 20, a light-emitting layer, and a second electrode layer (not shown). In one specific embodiment, the light-emitting layer includes multiple pixel units, including red pixel units 40 and green pixel units 50, and the multiple pixel units are arranged in a matrix; a thin film emitting red light is used as the red pixel unit 40, and a thin film emitting green light is used as the green pixel unit 50 to obtain a red and green dual-color array, which is excited by ultraviolet light irradiation, as shown... Figure 10 As shown, it can emit two different colors of light, with a resolution of 1200 PPI. Furthermore, the luminous layer obtained using organic materials has high luminous efficiency and is environmentally friendly, making it a good choice for combining micro-LEDs and OLEDs to achieve full-color displays.

[0092] Sixthly, this application also proposes a display device, which includes the display panel described above. The display device can be any electronic product with display functionality, including but not limited to smartphones, mobile phones, tablets, personal digital assistants (PDAs), portable multimedia players, televisions, game consoles, watch-type electronic devices, head-mounted displays, personal computer monitors, laptops, car navigation systems, car dashboards, digital cameras, portable video cameras, external advertising boards, electroluminescent panels, medical devices, testing devices, refrigerators, washing machines, etc.

[0093] The technical solutions and effects of this application will be described in detail below through specific embodiments and comparative examples. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0094] Example 1

[0095] The preparation method of the thin film in this embodiment is as follows:

[0096] (1) 4 t BuMB material (emitting red light) was dispersed in tetrahydrofuran to obtain a red NPs solution with a concentration of 500 mg / ml. Tetramethylammonium hydroxide surfactant was added to the solution at a mass ratio of 20:100 to NPs, and the mixture was thoroughly mixed. Then 5 ml of water was added, and the mixture was stirred vigorously for 30 s. Centrifugation was then performed to obtain red NPs nanoparticles with a particle size of 10–200 nm. The red NPs nanoparticles were dispersed in PGMEA to obtain a red NPs composite material solution with a concentration of 50 mg / ml, for later use.

[0097] (2) Take a glass substrate with a patterned ITO electrode layer on its surface. Drop a composite material solution onto the substrate, and then apply a voltage of 20V and an electric field strength of 5V / μm to the electrode layer. A thin film is gradually deposited on the surface of the electrode layer. Irradiate the thin film with ultraviolet light, such as... Figure 7 As shown, the thin film emits red light under ultraviolet irradiation.

[0098] Example 2

[0099] The scheme of this embodiment is basically the same as that of embodiment 1, except that in this embodiment, in step (1), the 4tBuMB material (emitting red light) is replaced with Ttrz-DI material (emitting green light). Accordingly, the obtained nanoparticles and composite material solutions are green NPs nanoparticles and green NPs composite material solutions, respectively. The film obtained in embodiment 2 is irradiated with ultraviolet light, as shown in the figure. Figure 8As shown, the thin film emits green light under ultraviolet irradiation.

[0100] Example 3

[0101] The scheme of this embodiment is basically the same as that of embodiment 1, except that in this embodiment, in step (1), the 4tBuMB material (emitting red light) is replaced with CzDABNA material (emitting blue light). Accordingly, the obtained nanoparticles and composite material solutions are blue NPs nanoparticles and blue NPs composite material solutions, respectively. The film obtained in embodiment 3 is irradiated with ultraviolet light, as shown in the figure. Figure 9 As shown, the thin film emits blue light under ultraviolet irradiation.

[0102] The composite materials, their preparation methods, and applications provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A composite material, characterized in that, It includes fluorescent organic nanomaterials and ionic surfactants, wherein the ionic surfactants are attached to the surface of the fluorescent organic nanomaterials; The fluorescent organic nanomaterials are selected from 1, 3, 7, 9 4(4) (tert-butyl)phenyl) 5,5 Difluoride 10 (2 (methoxyphenyl) 5H 4l4, 5l4 Dipyrrolo[1,2] c:2',1' f][1,3,2]diazaaniline, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole, 2,12-di-tert-butyl-N,N,5,9-tetra(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaza-13b-boraza[3,2,1-de]anthracene-7-amine; the ionic surfactant is selected from tetramethylammonium hydroxide; In the composite material, the mass ratio of the ionic surfactant to the fluorescent organic nanomaterial is 10–50:

100.

2. The composite material according to claim 1, characterized in that, The average particle size of the composite material is 10–200 nm.

3. A method for preparing a composite material, characterized in that, Includes the following steps: A first solution is provided, the first solution containing fluorescent organic nanomaterials and ionic surfactants; Provides a poor solvent for the fluorescent organic nanomaterials; The unsuitable solvent and the first solution are mixed, and then solid-liquid separation is performed to obtain a composite material. The composite material includes fluorescent organic nanomaterials and ionic surfactants, and the ionic surfactants are attached to the surface of the fluorescent organic nanomaterials. The fluorescent organic nanomaterials are selected from 1, 3, 7, 9 4(4) (tert-butyl)phenyl) 5,5 Difluoride 10 (2 (methoxyphenyl) 5H 4l4, 5l4 Dipyrrolo[1,2] c:2',1' f][1,3,2]diazaaniline, 5,10,15-tris(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole, 2,12-di-tert-butyl-N,N,5,9-tetra(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaza-13b-boraza[3,2,1-de]anthracene-7-amine; the ionic surfactant is selected from tetramethylammonium hydroxide; The mass ratio of the ionic surfactant to the fluorescent organic nanomaterial is 10–50:

100.

4. The preparation method according to claim 3, characterized in that, The unsuitable solvents include polar solvents, including one or more of methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, and water. The first solution further includes a nonpolar solvent, which includes one or more of tetrahydrofuran, toluene, chlorobenzene, chloroform, and octane.

5. A thin film, characterized in that, The material of the film includes the composite material as described in claim 1 or 2, or the composite material prepared by the preparation method as described in claim 3 or 4.

6. A method for preparing a thin film, characterized in that, Includes the following steps: A mixed solution is provided, the mixed solution comprising a polar solvent and a composite material, the composite material comprising the composite material of claim 1 or 2, or comprising the composite material prepared by the preparation method of claim 3 or 4; A thin film is obtained by depositing the composite material in the mixed solution through electrodeposition.

7. The preparation method according to claim 6, characterized in that, The polar solvent includes one or more of methanol, ethanol, ethyl acetate, propylene glycol methyl ether acetate, and water; and / or, In the mixed solution, the concentration of the composite material is 10–100 mg / ml.

8. The preparation method according to claim 6, characterized in that, The step of depositing the mixed solution to obtain a thin film by electrodeposition includes: A substrate is provided, the substrate including an electrode layer; The mixed solution is brought into contact with the substrate, and then a voltage is applied to the electrode layer to form an electric field, driving the composite material to deposit on the electrode layer to form a thin film.

9. The preparation method according to claim 8, characterized in that, The voltage is greater than 0V and less than or equal to 300V; and / or, The electric field strength is 0.01–10 V / μm.

10. The preparation method according to claim 8, characterized in that, The step of contacting the mixed solution with the substrate includes: Place the substrate in the mixed solution; or... The mixed solution is dropped onto the substrate.

11. A display panel, characterized in that, It includes a first electrode layer, a second electrode layer, and a light-emitting layer disposed between the first electrode layer and the second electrode layer, wherein the light-emitting layer includes the thin film according to claim 5, or includes the thin film prepared by the preparation method according to any one of claims 6 to 10.

12. A display device, characterized in that, Includes the display panel as described in claim 11.

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