Composition, light-emitting substrate and preparation method therefor, and light-emitting device

Abstract

The composition comprises: a quantum dot material and a first additive, wherein the first additive is selected from any one of the following structures represented by general formula (I): where R1 is selected from any one of an amino group, an alkyl-substituted amino group, a hydroxyl group, an alkoxy group, and an alkyl group; R2 is selected from any one of a substituted or unsubstituted alkylene group, a substituted or unsubstituted oxyalkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted heterocycloalkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, and a substituted or unsubstituted fused arylene group; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; n1 is a positive integer greater than or equal to 2; and under preset conditions, the first additive and the quantum dot material are bonded by means of chemical bonds.

Description

Composition, light-emitting substrate and its preparation method, light-emitting device Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a composition, a light-emitting substrate, a method for preparing the same, and a light-emitting device. Background Technology

[0002] Quantum dots (QDs), as novel light-emitting materials, possess advantages such as high light purity, high quantum efficiency, tunable color emission, and long lifespan, making them a research hotspot for novel LED (Light Emitting Diode) materials. Therefore, quantum dot light-emitting diodes (QLEDs) using quantum dot materials as the light-emitting layer have become a major research direction for novel display devices. Summary of the Invention

[0003] On one hand, a composition is provided comprising: a quantum dot material and a first additive, wherein the first additive is selected from any one of the structures shown in general formula I.

[0004] Wherein, R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted arylene, substituted or unsubstituted heteroaryl and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon and quaternary carbon; n1 is a positive integer greater than or equal to 2; under preset conditions, the first additive is chemically bonded to the quantum dot material.

[0005] In some embodiments, the first additive includes a first group, which is selected from any one of the groups shown in general formula II.

[0006] In the first additive, any two first groups have a first main chain connecting the two first groups, wherein the number of atoms in the first main chain between at least two first groups is less than or equal to 10.

[0007] In some embodiments, the concentration of the first additive in the composition is less than 2 g / L.

[0008] In some embodiments, the first additive comprises at least one of: trimethylolpropane trimethacrylate, bisphenol A-dimethacrylate, ethylene glycol dimethacrylate, dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate), and tetraethylene glycol dimethacrylate.

[0009] In some embodiments, the first additive further includes an aromatic amine group.

[0010] In some embodiments, the quantum dot material includes: a quantum dot body and a first ligand group coordinated and connected to the quantum dot body; the end of the first ligand group away from the quantum dot body includes: a second group; the second group is selected from any one of the groups shown in General Formula III below.

[0011] R5 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl.

[0012] In some embodiments, the first ligand group includes a coordinating group, which is coordinated to the quantum dot body, and the coordinating group includes at least one of carboxyl, thiol and amino groups.

[0013] In some embodiments, the quantum dot material comprises any one of the structures shown in general formula IV.

[0014] Wherein, R4 is the coordinating group; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted arylene, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused arylene; n2 is a positive integer greater than or equal to 1; n3 is a positive integer greater than or equal to 1; The quantum dot itself.

[0015] In some embodiments, R6 includes a second main chain connecting R4 and the second group, the second main chain having 15 or fewer atoms.

[0016] In some embodiments, R6 further includes at least one of an ester bond and an ether bond.

[0017] In some embodiments, the quantum dot material further includes a second ligand group coordinated to the quantum dot body, the second ligand group comprising a coordinating group; the second ligand group is different from the first ligand group.

[0018] In some embodiments, the ratio of the sum of the mass of the first ligand group and the mass of the second ligand group to the mass of the quantum dot material ranges from 3 to 10.

[0019] In some embodiments, the quantum dot body comprises at least one of group II-VI semiconductor compounds, group III-V semiconductor compounds, group III-VI semiconductor compounds, group I-III-VI semiconductor compounds, group IV-VI semiconductor compounds, and group IV elements or compounds.

[0020] In some embodiments, the composition further includes a photoinitiator; under the action of light and the photoinitiator, the first additive is chemically bonded to the quantum dot material.

[0021] In some embodiments, the photoinitiator is selected from any of the structures shown in general formula V.

[0022] Wherein, R7 is selected from any one of substituted or unsubstituted alkyl groups of C1 to C10, substituted or unsubstituted cycloalkyl groups of C3 to C10, and substituted or unsubstituted heterocycloalkyl groups of C3 to C10; R8 includes any one of ester bonds and ether bonds, and two R8s may be the same or different; n4 is a positive integer greater than or equal to 1.

[0023] In some embodiments, the ratio of the mass of the photoinitiator to the mass of the quantum dot material ranges from 0.005 to 0.15.

[0024] In some embodiments, the composition further includes a second additive, the second additive comprising any one of the structures shown in general formula VI.

[0025] In some embodiments, the composition further includes a solvent, said solvent comprising at least one of propylene glycol methyl ether acetate, butyl lactate, ethyl 3-ethoxypropionate, and diethylene glycol monoethyl ether acetate.

[0026] In some embodiments, the quantum dot material includes any one of red quantum dot material, green quantum dot material, and blue quantum dot material; wherein, the composition including red quantum dot material is a first composition, the composition including green quantum dot material is a second composition, and the composition including blue quantum dot material is a third composition; the concentration of the first additive in the first composition is greater than the concentration of the first additive in the second composition, and the concentration of the first additive in the first composition is greater than the concentration of the first additive in the third composition.

[0027] On the other hand, a light-emitting substrate is provided, the light-emitting substrate including: a plurality of light-emitting devices disposed on the substrate, each of the plurality of light-emitting devices including: a first electrode, a second electrode, and a light-emitting pattern disposed between the first electrode and the second electrode.

[0028] The material of the luminescent pattern includes any one of the structures shown in Formula VII.

[0029] Wherein, R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; n1 is a positive integer greater than or equal to 2; It is the quantum dot body.

[0030] In some embodiments, the material of the luminescent pattern further includes any of the structures shown in Formula VIII.

[0031] Among them, two R4s are the same or different; two R5s are the same or different; two R6s are the same or different.

[0032] In some embodiments, the material of the luminescent pattern further includes any of the structures shown in Formula IX.

[0033] Wherein, R7 is selected from any one of substituted or unsubstituted alkyl groups of C1-C10, substituted or unsubstituted cycloalkyl groups of C3-C10, and substituted or unsubstituted heterocycloalkyl groups of C3-C10; R8 includes any one of ester bonds and ether bonds, and two R8s may be the same or different; n3 is a positive integer greater than or equal to 1; n4 is a positive integer greater than or equal to 1; -CR 61 R 62 R 63 The group remaining after removing one hydrogen atom from R6.

[0034] In some embodiments, the plurality of light-emitting devices include: a first light-emitting device, a second light-emitting device, and a third light-emitting device, wherein the first light-emitting device is configured to emit red light, the second light-emitting device is configured to emit green light, and the third light-emitting device is configured to emit blue light.

[0035] The luminescent pattern of the first light-emitting device is formed by chemically bonding a first additive of the first composition with a red quantum dot material under preset conditions. The luminescent pattern of the second light-emitting device is formed by chemically bonding a first additive of the second composition with a green quantum dot material under preset conditions. The luminescent pattern of the third light-emitting device is formed by chemically bonding a first additive of the third composition with a blue quantum dot material under preset conditions. The concentration of the first additive in the first composition is greater than the concentration of the first additive in the second composition, and the concentration of the first additive in the first composition is greater than the concentration of the first additive in the third composition.

[0036] In another aspect, a method for fabricating a light-emitting substrate is provided, the method comprising: forming a first electrode on one side of the substrate;

[0037] A composition is coated on the side of the first electrode away from the substrate; wherein the composition comprises: a quantum dot material and a first additive, the first additive being selected from any of the structures shown in general formula I; under preset conditions, the first additive is chemically bonded to the quantum dot material.

[0038] Expose a target area for forming a luminescent pattern; develop a composition to remove areas outside the target area to form the luminescent pattern; wherein the material of the luminescent pattern includes any one of the structures shown in general formula VII.

[0039] In another aspect, a light-emitting device is provided, comprising: a light-emitting substrate and a driving chip as described in any of the above embodiments, wherein the driving chip is used to drive the light-emitting substrate to emit light. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual process of the method, etc. involved in the embodiments of this disclosure.

[0041] Figure 1 is a structural diagram of a quantum dot material cross-linked with a first ligand group according to some embodiments of the present disclosure;

[0042] Figure 2 is a scanning electron microscope image of quantum dot materials cross-linked by a first ligand group according to some embodiments of the present disclosure;

[0043] Figure 3 is a structural diagram of a quantum dot material according to some embodiments of the present disclosure after crosslinking with a first ligand group and a first additive;

[0044] Figure 4 is a scanning electron microscope image of a quantum dot material according to some embodiments of the present disclosure after crosslinking with a first ligand group and a first additive;

[0045] Figure 5 is a crosslinking reaction diagram of the compositions according to some embodiments of the present disclosure under light irradiation conditions;

[0046] Figure 6 is a thermogravimetric analysis diagram of quantum dot materials according to some embodiments of the present disclosure;

[0047] Figure 7 is an experimental diagram of pure development of the composition without exposure according to Comparative Example 1.1 of this disclosure;

[0048] Figure 8 is a scanning electron microscope image of the composition according to Comparative Example 1.2 of this disclosure after exposure and development and without exposure and development;

[0049] Figure 9 is a scanning electron microscope image of the composition after exposure and development and without exposure and development according to Example 1.3 of this disclosure;

[0050] Figure 10 is a scanning electron microscope image of the composition after exposure and development according to Example 2 of this disclosure;

[0051] Figure 11 is a scanning electron microscope image of the composition after exposure and development according to Example 3 of this disclosure;

[0052] Figure 12 is a scanning electron microscope image of the composition after exposure and development according to Example 4 of this disclosure;

[0053] Figure 13 is a photograph of the actual objects after being placed in the dark according to Embodiment 5.1 and Comparative Example 5.2 of this disclosure;

[0054] Figure 14 is a structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0055] Figure 15 is a flowchart of a method for preparing a light-emitting substrate according to some embodiments of the present disclosure;

[0056] Figures 16 and 17 are structural diagrams of each step in the fabrication method of a light-emitting substrate according to some embodiments of the present disclosure;

[0057] Figure 18 is a structural diagram of a light-emitting device according to some embodiments of the present disclosure. Detailed Implementation

[0058] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0059] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0060] Hereinafter, 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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0061] In describing some embodiments, the terms "coupled" and "connected," and their derivative expressions, may be used. The term "connected" should be interpreted broadly; for example, a "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection via an intermediate medium. The term "coupled," for example, indicates that two or more components have direct physical or electrical contact. The term "coupled" or "communicatively coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0062] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0063] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0064] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0065] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0066] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0067] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0068] Quantum dots (QDs), as a new type of luminescent material, have advantages such as excellent color purity, long lifetime, and high quantum yield of light emission, and have become a major research direction for new display technologies in recent years.

[0069] For example, the patterning of quantum dot light-emitting layers (or films) includes direct photolithography. Direct photolithography can be achieved by constructing photosensitive ligands on the surface of quantum dots. After being exposed to light, the photosensitive ligands on the surface undergo changes such as decomposition, cross-linking, and desorption, thereby affecting the solubility of quantum dots in the developer. Finally, the patterning design of the film is achieved by relying on the difference in solubility of quantum dots in the developer in the target exposure area and the non-target exposure area.

[0070] In direct lithography, when forming quantum dots of different colors, residual quantum dots in non-target pixel areas (or non-target exposure areas) can cause pixel color mixing in full-color devices, thus limiting the final device's color gamut. Meanwhile, a denser film quality in the target exposure area is crucial for ensuring no leakage and uniform luminous morphology in the light-emitting device. Therefore, maximizing the density of the quantum dot luminescent layer structure while ensuring good development is essential for the application of quantum dot direct lithography. Density, also known as packing ratio or maximum space utilization, represents the ratio of the volume occupied by atoms in a unit cell to the volume of the unit cell. It is a parameter that measures the tightness of atomic arrangement; the higher the density, the tighter the atomic arrangement in the crystal, and the more compact the crystal structure.

[0071] However, strong development processes for low quantum dot residue usually cause some damage to the film quality in the target exposure area. Although extending the exposure time can ensure the continuity of the film, quantum dots exposed to ultraviolet light for a long time will experience a certain degree of deterioration in luminescence performance, which will lead to the degradation of device performance.

[0072] Based on this, embodiments of the present disclosure provide a composition comprising: a quantum dot material, the quantum dot material comprising: a quantum dot body and a ligand coordinated to the quantum dot body.

[0073] In some examples, the quantum dot bulk includes any one of the following: group IIB-VIA quantum dots, group IIIA-VA quantum dots, group IVA-VIA quantum dots, core-shell quantum dots, and ABX3-type perovskite quantum dots. In ABX3-type perovskite quantum dots, A is CH3NH3. + (methylamine), NH2CH=NH2 (formamidinium) and Cs + One or more of them, where B is Pb 2+ and Sn 2+ One or two of them, X is Cl - ,Br - and I- One or more of the following, ABX3 type perovskite quantum dots include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3 and CsPbI3.

[0074] For example, group IIB-VIA quantum dots are selected from: one or more binary compounds such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS; and ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and CdZn Te, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or mixtures thereof; and quaternary compounds such as HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, or mixtures thereof, but not limited thereto.

[0075] IIIA-VA group quantum dots are selected from: binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or mixtures thereof; ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, or mixtures thereof; and quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or mixtures thereof, but not limited thereto.

[0076] Group IVA-VIA quantum dots are selected from: binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, or mixtures thereof; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, or mixtures thereof; and quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, or mixtures thereof, but are not limited thereto. Group IVA-VIA quantum dots are selected from, for example, elemental (monological) semiconductors such as Si, Ge, or mixtures thereof; and binary semiconductor compounds such as SiC, SiGe, and mixtures thereof, but are not limited thereto.

[0077] A core-shell quantum dot is a quantum dot in which one material forms the core and the other forms the shell. For example, a CdS / ZnS quantum dot means that the core is made of CdS and the shell is made of ZnS.

[0078] In some examples, the ligands that coordinate with the quantum dot bulk include, for example, oleic acid, phosphoric acid, sulfonic acid, thiols or amino groups, etc. There is no limitation here. This type of ligand is called a second ligand group.

[0079] The second ligand group includes a coordinating group that is coordinated to the quantum dot bulk. For example, the coordinating group includes at least one of carboxyl (-COOH), mercapto (-SH), and amino (-NH3).

[0080] Because quantum dots are very small in size and have a large specific surface area, they are prone to aggregation, and their surfaces have many defects. Therefore, in applications, the surface of quantum dots is usually modified with ligands. The second ligand group not only protects the quantum dot matrix but also improves its solubility in solution.

[0081] In some examples, the quantum dot material further includes a first ligand group coordinated to the quantum dot bulk. The first ligand group includes a coordinating group.

[0082] For example, the quantum dot body and the first ligand group coordinated with the quantum dot body include any of the structures shown in general formula X below.

[0083] Wherein, R4 is a coordinating group. The quantum dot is a quantum dot body, and the ligand group is coordinated with the quantum dot body to achieve the connection between the first ligand group and the quantum dot body.

[0084] R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heterocycloalkylene, substituted or unsubstituted arylene, substituted or unsubstituted heteroarylene, and substituted or unsubstituted fused-ring arylene; R6 is used to connect R4 and R9. The heteroarylene can be furanyl, pyranyl, thiophenyl, or pyridinyl, etc., and is not limited herein. The fused-ring arylene can be naphthyl, indolyl, or pyrroleyl, etc., and is not limited herein.

[0085] n4 is a positive integer greater than or equal to 1, for example, n4 can be 1, 2, 3, 4, 5, 6, 8, 10 or 15, etc., and there is no restriction here. By taking different values ​​of n4, the quantum dot body can be connected to one or more first ligand groups.

[0086] R9 is a photosensitive group that can undergo free radical polymerization. For example, R9 includes: mercapto (-SH), vinyl (-CH=CH2), propenyl (-CH=CHCH3), methacryloyloxy, or acryloxy, etc., without limitation. Free radical polymerization is a polymerization reaction initiated by a free radical, causing the chain-growing (chain-growth) free radical to continuously grow.

[0087] Figure 1 shows the structure of the quantum dot material after cross-linking through the first ligand group. Under the action of the photoinitiator, the photosensitive groups in the first ligand group are connected to achieve cross-linking of the quantum dot material.

[0088] Figure 2 is a scanning electron microscope image of the quantum dot material after cross-linking through the first ligand group. As can be seen from Figure 2, a quantum dot luminescent layer is formed after the composition is exposed and developed.

[0089] In some examples, the composition further includes a first additive selected from any of the structures shown in general formula I.

[0090] Wherein, R1 is selected from any one of amino (-NH3), alkyl-substituted amino, hydroxyl (-OH), alkoxy, and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; n1 is a positive integer greater than or equal to 2. Furthermore, under preset conditions, the first additive is chemically bonded to the quantum dot material.

[0091] For example, under conditions of light and photoinitiator, the first additive connects with the photosensitive group of the first ligand group on the quantum dot matrix to form a cross-linked network.

[0092] For example, alkyl-substituted amino groups include monoalkyl-substituted amino groups and dialkyl-substituted amino groups, where alkyl groups include methyl, ethyl, propyl, or butyl, etc., and there is no limitation herein.

[0093] R1 stands for electron-donating group, which is a group that has electron-donating properties and can donate electrons to surrounding atoms or groups.

[0094] The first additive includes a first group, which is selected from any one of the groups shown in general formula II below.

[0095] in, · This indicates that the oxygen (O) at this location in the first group is used to connect with R2.

[0096] The first group is a photosensitive group capable of undergoing free radical polymerization. Under the action of a photoinitiator, the double bond of the first group opens, and an addition reaction occurs.

[0097] Taking R1 as a methyl group as an example, the first group is methacryloyloxy, with the chemical formula C4H5O2. · With a relative atomic mass of 85.0813, the structural formula of methacryloyloxy is as follows.

[0098] R2 is used to connect R3 and the first group.

[0099] The value of n1 can be 2, 3, 4, 5, 6, 7, 8, or 9, etc., and there is no limitation here. Furthermore, n1 can be greater than or equal to 4. By setting the value of n1, multiple first groups in the first additive can participate in the free radical polymerization reaction, which can improve the crosslinking degree of the quantum dot material and further improve the density of the quantum dot light-emitting layer formed by the composition.

[0100] R3 is selected from any of the secondary, tertiary, and quaternary carbon groups to ensure that the first additive includes multiple first groups. For example, if R3 is a secondary carbon group, R3 connects two first groups through two R2 groups, so that the first additive includes two first groups; if R3 is a tertiary carbon group, R3 connects three first groups through three R2 groups, so that the first additive includes three first groups; if R3 is a quaternary carbon group, R3 connects four first groups through four R2 groups, so that the first additive includes four first groups. In the first additive, R2 can be the same or different, and there is no limitation here.

[0101] An additive having multiple first groups can be called a multi-branched structure, with each branch containing one first group, and each first group can participate in free radical polymerization.

[0102] Furthermore, the carbon chain of R2 may further include at least one secondary carbon, at least one tertiary carbon, and / or at least one quaternary carbon, and each carbon branch may be connected to a first group to form a first additive comprising five or more first groups to form five or more branches.

[0103] Figure 3 shows the structure of the quantum dot material after cross-linking through the first ligand group and the first additive. Under the action of light and photoinitiator, the photosensitive group in the first ligand group is connected to realize the cross-linking of the quantum dot material. At the same time, the first additive in the composition is cross-linked with the quantum dot material connected to the first ligand group, and a cross-linked network structure of quantum dot material with a high degree of cross-linking is obtained.

[0104] Figure 4 is a scanning electron microscope image of the quantum dot material after cross-linking with the first ligand group and the first additive. As can be seen from Figure 4, the composition forms a quantum dot luminescent layer after exposure and development. Moreover, compared with the quantum dot luminescent layer after cross-linking with the first ligand group shown in Figure 2, the quantum dot luminescent layer after cross-linking with the first ligand group and the first additive has a higher density.

[0105] Therefore, the embodiments of this disclosure, by adding a multi-branched first additive dispersed in the solvent of the composition, can connect more quantum dot materials in the free radical polymerization reaction, thereby enabling the quantum dot materials to form a strong cross-linked network under low-dose exposure conditions, so as to obtain a film layer with high density.

[0106] Furthermore, in order to ensure the development effect while achieving the density of the quantum dot light-emitting layer structure, the materials of the composition are optimized as follows.

[0107] In some embodiments, any two first groups have a first main chain connecting the two first groups, wherein the number of atoms in the first main chain between at least two first groups is less than or equal to 10.

[0108] For example, the number of atoms in the first main chain between two first groups is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc., and there is no limitation here.

[0109] The cross-linking degree of the quantum dot material can be guaranteed by ensuring that the number of atoms in the first main chain between the first groups in the first additive is less than or equal to 10, which is beneficial to improving the density of the film. Experimental data on the benefits of having less than or equal to 10 atoms in the first main chain between the first groups in the first additive to improve the density of the film will be provided later and will not be elaborated here.

[0110] Moreover, the first main chain can be a flexible chain. Flexible chains have strong bendability and good flexibility during cross-linking, which is beneficial for the cross-linking of quantum dots in free radical polymerization.

[0111] In some embodiments, the first additive further includes at least one of ester bonds and ether bonds.

[0112] The first additive also includes at least one of ester bonds and ether bonds, which can increase the solubility of the first additive in the solvent of the composition, which is beneficial for the development and removal of the composition in non-target exposure areas, and reduces the residual quantum dots in non-target exposure areas, thereby alleviating the pixel color mixing problem of full-color devices.

[0113] In some embodiments, the concentration of the first additive in the composition is less than 2 g / L.

[0114] For example, in the composition, the concentration of the first additive is 0.05 g / L, 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.25 g / L, 0.5 g / L, 0.5 g / L, 0.75 g / L, 1 g / L, 1.25 g / L, 1.5 g / L, 1.75 g / L, 1.8 g / L, 1.85 g / L, 1.9 g / L, or 1.95 g / L, etc., and there is no limitation here.

[0115] By setting the concentration of the first additive in the composition to be less than 2 g / L, it is possible to ensure that the film obtained by the composition has good density. Experimental data on ensuring that the concentration of the first additive in the composition is less than 2 g / L to ensure that the film obtained by the composition has good density will be provided later and will not be described here.

[0116] In some embodiments, the first additive includes at least one of trimethylolpropane trimethacrylate, bisphenol A-dimethacrylate, ethylene glycol dimethacrylate, dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate), and tetraethylene glycol dimethacrylate.

[0117] The English name for trihydroxymethylpropyl trimethylacrylate is Trihydroxymethylpropyl trimethylacrylate, and its chemical formula is C60-32 ... 18 H 26 O6, with a molecular weight of 338.4, has the following structural formula for trimethylolpropane trimethacrylate.

[0118] The English name of bisphenol A-dimethyl acrylate is 2-Propenoic acid, 2-methyl-,1,1'-[(1-methylethylidene)di-4,1-phenylene]ester, and its chemical formula is C1. 23 H 24 O4, with a molecular weight of 364.43, has the following structural formula for bisphenol A-dimethacrylate.

[0119] Ethylene glycol dimethacrylate has the chemical formula C. 10 H 14 O4, with a molecular weight of 198.22, has the following structural formula for ethylene glycol dimethacrylate.

[0120] The structural formula of dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate) is as follows.

[0121] The English name for tetraethylene glycol dimethacrylate is Tetraethylene glycol dimethacrylate, and its molecular formula is C6H2O. 16 H 26 O7, with a molecular weight of 330.37, has the following structural formula for tetraethylene glycol dimethacrylate.

[0122] The first additive in the above structure can enable the quantum dot material to form a strong cross-linked network under low-dose exposure conditions, so as to obtain a relatively dense quantum dot light-emitting layer.

[0123] In some embodiments, the first additive further includes an aromatic amine group.

[0124] For example, the first main chain connecting the two first groups may have aromatic amine groups.

[0125] Aromatic amine groups are hole transport groups, which are functional groups in organic semiconductor materials that can efficiently transport holes (i.e., positively charged carriers). Aromatic amine groups have enhanced π-π interactions and good conjugation.

[0126] To improve the stability of quantum dot materials, the structure of the first ligand group of the quantum dot material is optimized as follows.

[0127] In some embodiments, the end of the first ligand group away from the quantum dot body includes a second group; the second group is a photosensitive group capable of undergoing free radical polymerization, that is, the second group is R9 in the quantum dot material with the structure shown in general formula X, and further, the second group is selected from any one of the groups shown in general formula III.

[0128] R5 is selected from any one of amino (-NH3), alkyl-substituted amino, hydroxyl (-OH), alkoxy and alkyl, and R5 is an electron-donating group.

[0129] By using any of the groups shown in General Formula III as the second group of the first ligand group, the quantum dot material can be made more stable, allowing for long-term storage and convenient use. Experimental data on how using any of the groups shown in General Formula III as the second group of the first ligand group can ensure the stability of the quantum dot material will be discussed later and will not be elaborated here.

[0130] Furthermore, both the first ligand group and the first additive include electron-donating groups, which can compensate for the difference in electron cloud density on the double bonds caused by the ester bond (the ester bond has an electron-withdrawing effect), thus stabilizing the free radical activity. Moreover, the first ligand group and the first additive molecule have the same or similar photosensitive groups, which can prevent competition in the cross-linking reaction caused by differences in double bond activity, further improving the degree of cross-linking of the quantum dot material.

[0131] In some examples, quantum dot materials include any of the structures shown in general formula IV below.

[0132] Wherein, R4 is a coordinating group; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl. R5 is selected from any one of amino (-NH3), alkyl-substituted amino, hydroxyl (-OH), alkoxy, and alkyl, and R5 is an electron-donating group.

[0133] n2 is a positive integer greater than or equal to 1, such as 1, 2, or 3, etc., without any restrictions. By varying the value of n2, R6 can connect to one or more second groups. For example, when n is 2, the quantum dot material has the following structural formula.

[0134] n3 is a positive integer greater than or equal to 1, for example, n3 can be 1, 2, 3, 4, 5, 6, 8, 10, or 15, etc., and there is no restriction here. By taking different values ​​of n3, the quantum dot body can be connected to one or more first ligand groups.

[0135] It is understandable that in quantum dot materials with structures as shown in Formula IV, a second ligand group is also attached to the quantum dot body. For an introduction to the second ligand group, please refer to the above content, and it will not be repeated here.

[0136] In some examples, in quantum dot materials with the structure shown in Formula IV, R6 includes a second main chain connecting R4 and the second group, the number of atoms in the second main chain being less than or equal to 15.

[0137] For example, the number of atoms in the second main chain can be 1, 2, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14 or 15, etc., and there is no limit here.

[0138] By ensuring that the number of atoms in the second main chain of R6 is less than or equal to 15, the quantum dot material can be better dispersed in the solvent of the composition, and the first ligand groups on the surface of the quantum dot body will not affect the crosslinking between quantum dot materials or between the quantum dot material and the first additive.

[0139] In some examples, R6 also includes at least one of an ester bond and an ether bond.

[0140] R6 also includes at least one of ester and ether bonds, which can increase the dispersibility of quantum dot materials in the solvent of the composition, which is beneficial for the development and removal of the composition in non-target exposure areas, and reduces the residue of quantum dots in non-target exposure areas, thereby alleviating the pixel color mixing problem of full-color devices.

[0141] In some embodiments, under conditions of light (hv) and a photoinitiator, the quantum dot material and the first additive are connected by chemical bonds to form a cross-linked network, as shown below.

[0142] R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; n1 is a positive integer greater than or equal to 2.

[0143] R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxyl, alkoxy, and alkyl; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl.

[0144] For an introduction to R1, R2, R3, R4, R5, and R6, please refer to the above content; it will not be repeated here.

[0145] In this reaction, under the action of light and photoinitiator, the double bonds in the second group of the quantum dot material and the double bonds in the first group of the first additive are opened, and the quantum dot material is polymerized through free radical reaction, so that the quantum dot material forms a cross-linked network under the linkage of the first additive, so as to obtain a quantum dot light-emitting layer with high density.

[0146] In this example, the crosslinking reaction is described using a quantum dot body with a first ligand group attached to it, and the first ligand group includes a second group. When multiple first ligand groups are attached to the quantum dot body, and / or each first ligand group includes multiple second groups, each second group on the quantum dot body can crosslink with the first group of the first additive to form a crosslinking network.

[0147] In some examples, the first and second groups can be the same.

[0148] For example, both the first group and the second group are methyl groups.

[0149] For example, the first ligand group of the quantum dot material is succinic acid mono[2-[(2-methyl-acryloyl)oxy]ethyl] ester (4-[2-(2-methylprop-2-enoyloxy)ethoxy]-4-oxobutanoic acid, abbreviated as MMES) after being linked to the quantum dot matrix, and the first additive is trimethylolpropane trimethacrylate. The crosslinking reaction of the quantum dot material and the first additive under the conditions of light irradiation and photoinitiator is described below.

[0150] The chemical formula of mono[2-[(2-methylacryloyl)oxy]ethyl] succinate is C 10 H 14 O6, with a molecular weight of 230.21, has the following structural formula for mono[2-[(2-methyl-acryloyl)oxy]ethyl] succinate.

[0151] In MMES, the carboxyl group (-COOH) is linked to the quantum dot matrix after the hydrogen atom (H) is removed.

[0152] The reaction formula for the crosslinking reaction between quantum dot materials and the first additive is as follows.

[0153] In some embodiments, under conditions of light and a photoinitiator, the general formula for the cross-linking structure formed by the connection between quantum dot materials is shown below.

[0154] R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxyl, alkoxy, and alkyl groups; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl. n2 is a positive integer greater than or equal to 1.

[0155] For an introduction to R4, R5, and R6, please refer to the above content; it will not be repeated here.

[0156] Among them, two R4s are the same or different; two R5s are the same or different; two R6s are the same or different.

[0157] In this reaction, under the influence of light and a photoinitiator, the double bonds in the second group of the quantum dot material open and polymerize through a free radical reaction, resulting in a cross-linked structure of the quantum dot material.

[0158] In this example, the crosslinking reaction is illustrated by taking a quantum dot body with a first ligand group attached to it, and the first ligand group including a second group. When each quantum dot body is attached to multiple first ligand groups, and / or each first ligand group is attached to multiple second groups, each second group on the quantum dot body can react to form a crosslinked structure.

[0159] Taking the structure of quantum dot material with MMES as the first ligand group connected to the quantum dot body as an example, the cross-linking reaction between quantum dot materials under the conditions of light irradiation and photoinitiator is illustrated.

[0160] Figure 5 shows the crosslinking reaction of the composition under light irradiation conditions, wherein the first ligand group of the quantum dot material is the structure after MMES is connected to the quantum dot body, and the first additive is trimethylolpropane trimethacrylate.

[0161] As shown in Figure 5, the composition provided in the embodiments of this disclosure, by adding a first additive, not only exhibits cross-linking between quantum dot materials through the first ligand groups, but also cross-linking between quantum dot materials through the first additive. The first additive can connect more quantum dots in the free radical polymerization reaction, thereby enabling the quantum dots to form a robust cross-linked network under low-dose exposure conditions, resulting in a relatively dense quantum dot luminescent layer.

[0162] As described above, quantum dot materials include: a quantum dot matrix, a first ligand group coordinated with the quantum dot matrix, and a second ligand group coordinated with the quantum dot matrix. Furthermore, the second ligand group is different from the first ligand group.

[0163] In some examples, the ratio of the mass of the first ligand group to the sum of the masses of the second ligand group and the mass of the quantum dot material ranges from 3 to 10.

[0164] For example, the ratio of the mass of the first ligand group to the mass of the second ligand group to the mass of the quantum dot material is 3, 4, 5, 6, 7, 8, 9 or 10, etc., and there is no limitation here.

[0165] For example, the ratio of the mass of the first ligand group to the mass of the quantum dot material is less than 3.

[0166] Figure 6 shows the thermogravimetric analysis (TG) plot of the quantum dot material. The horizontal axis represents the reaction time in seconds (s), and the vertical axis represents the weight percentage (%). As can be seen from Figure 6, there are two weight loss events between 2000 s and 8000 s. The first weight loss occurs between 2000 s and 3000 s, involving the first ligand group, with a weight loss percentage of less than 3%. The second weight loss occurs between 7000 s and 8000 s, involving the second ligand group, with a weight loss percentage of approximately 7%.

[0167] By setting the ratio of the mass of the first ligand group to the mass of the quantum dot material to a value ranging from 3 to 10, the ligand group can both protect the quantum dot matrix and ensure good dispersibility of the quantum dot matrix in solution. When the ratio of the mass of the first ligand group to the mass of the quantum dot material is less than 3, the mass of the first ligand group meets the requirements for forming a cross-linked structure of the quantum dot material, resulting in a film with high density.

[0168] The embodiments disclosed herein are optimized for the selection of the quantum dot body of the composition.

[0169] In some examples, the quantum dot body includes at least one of group II-VI semiconductor compounds, group III-V semiconductor compounds, group III-VI semiconductor compounds, group I-III-VI semiconductor compounds, group IV-VI semiconductor compounds, and group IV elements or compounds.

[0170] For example, the quantum dot body may include group II-VI semiconductor compounds, group III-V semiconductor compounds, group III-VI semiconductor compounds, group I-III-VI semiconductor compounds, group IV-VI semiconductor compounds, group IV elements or compounds, or any combination thereof.

[0171] Examples of group II-VI semiconductor compounds include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, or MgS; and ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdSeS, CdSeTe, CdSTe ... dZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe or MgZnS; quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe or HgZnSTe; or any combination thereof.

[0172] Examples of Group III-V semiconductor compounds may include: binary compounds, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, or InSb; ternary compounds, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, or InPSb; quaternary compounds, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; or any combination thereof. Furthermore, Group III-V semiconductor compounds may further include Group II elements. Examples of group III-V semiconductor compounds that further include group II elements include InZnP, InGaZnP, InAlZnP, etc.

[0173] Examples of group III-VI semiconductor compounds are: binary compounds, such as GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, or InTe; ternary compounds, such as InGaS3 or InGaSe3; and any combination thereof.

[0174] Examples of group I-III-VI semiconductor compounds are ternary compounds, such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, or AgAlO2; or any combination thereof.

[0175] Examples of group IV-VI semiconductor compounds are: binary compounds, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; ternary compounds, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; quaternary compounds, such as SnPbSSe, SnPbSeTe, or SnPbSTe; or any combination thereof.

[0176] Group IV elements or compounds may include: single-element compounds, such as Si or Ge; binary compounds, such as SiC or SiGe; or any combination thereof.

[0177] In addition, the quantum dot can be a single structure or a core-shell dual structure.

[0178] For example, the compositions provided in the embodiments of this disclosure are used to form electroluminescent quantum dot light-emitting layers.

[0179] By specifying the type of quantum dot matrix, this composition can be used to form an electroluminescent quantum dot light-emitting layer. Furthermore, the ligand exchange process for the aforementioned quantum dot matrix is ​​relatively stable.

[0180] The following describes the photoinitiator used in the embodiments of this disclosure.

[0181] In some examples, the photoinitiator includes at least one of a free radical photoinitiator and an ionic photoinitiator.

[0182] For example, photoinitiators include benzophenone-based photoinitiators, the structural formula of which is shown below.

[0183] For example, the photoinitiator is selected from any of the structures shown in general formula V below.

[0184] Wherein, R7 is selected from any one of substituted or unsubstituted alkyl groups of C1 to C10, substituted or unsubstituted cycloalkyl groups of C3 to C10, and substituted or unsubstituted heterocycloalkyl groups of C3 to C10; R8 includes any one of ester bonds and ether bonds, and two R8s may be the same or different; n4 is a positive integer greater than or equal to 1.

[0185] Wherein, alkyl, cycloalkyl, and heterocycloalkyl in Cn refer to the corresponding groups that have a total of n carbon (C) atoms.

[0186] By including either ester or ether bonds in R8, the solubility of the photoinitiator in the solvent of the composition can be increased.

[0187] The photoinitiator with the structure shown in general formula V is a free radical photoinitiator. Under light irradiation, it generates free radicals, which initiate free radical polymerization reactions between the second groups to achieve cross-linking of the quantum dot material, and free radical polymerization reactions between the second group and the first group of the first additive to achieve cross-linking of the quantum dot material, thereby forming a quantum dot light-emitting layer with high density.

[0188] In some embodiments, the ratio of the mass of the photoinitiator to the mass of the quantum dot material ranges from 0.005 to 0.15.

[0189] For example, the ratio of the mass of the photoinitiator to the mass of the quantum dot material can be 0.005, 0.01, 0.015, 0.02, 0.03, 0.035, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15, etc., and there is no limitation here.

[0190] By setting the ratio of the mass of the photoinitiator to the mass of the quantum dot material to be in the range of 0.005 to 0.15, the photoinitiator can meet the requirements for use and initiate cross-linking between the quantum dot materials.

[0191] In some embodiments, the composition further includes a second additive, the second additive comprising any one of the structures shown in general formula VI below.

[0192] Wherein, R4 is a coordinating group; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl. R5 is selected from any one of amino (-NH3), alkyl-substituted amino, hydroxyl (-OH), alkoxy, and alkyl, and R5 is an electron-donating group.

[0193] n3 is a positive integer greater than or equal to 1, for example, n3 can be 1, 2, or 3, etc., and there is no restriction here. By taking different values ​​of n3, R6 can be connected to one or more second groups. For an introduction to the second groups, please refer to the introduction of the groups shown in general formula III, and it will not be repeated here.

[0194] After the hydrogen atom (H) on R4 detaches from the second additive, R4 can connect with the quantum dot body to form the first ligand group.

[0195] For example, the second additive is MMES.

[0196] Including a second additive in the composition can increase the dispersibility of the quantum dot material in the solution, which helps to reduce the residue of the composition after development of non-target exposure areas. The second additive dispersed in the solution and the first ligand groups coordinated to the quantum dot matrix undergo a dynamic adsorption and desorption process. The molecules of the second additive can inhibit the desorption reaction of the first ligand groups, maintaining the stability of the solution.

[0197] In some embodiments, the composition further includes a solvent, which includes at least one of propylene glycol methyl ether acetate, butyl lactate, ethyl 3-ethoxypropionate, and diethylene glycol monoethyl ether acetate.

[0198] Propylene glycol methyl ether acetate, abbreviated as PGMEA, has the molecular formula C6H. 12 O3 has a molecular weight of 160.21084.

[0199] The English name for butyl lactate is n-Butyl Lactate, and its molecular formula is C7H. 14 O3 has a molecular weight of 146.1843.

[0200] Ethyl 3-ethoxypropionate has the molecular formula C7H. 14 O3 has a molecular weight of 146.1843.

[0201] Diethylene glycol monoethyl ether acetate, also known as 2-(2-Ethoxyethoxy)ethyl Acetate, has the molecular formula C8H10. 16 O4 has a molecular weight of 176.21.

[0202] The quantum dot material in the composition has good dispersibility in the solvent, and the first additive and the second additive have good solubility in the solvent.

[0203] In some embodiments, the quantum dot material includes any one of red quantum dot material, green quantum dot material, and blue quantum dot material.

[0204] The composition comprising red quantum dot material is the first composition, the composition comprising green quantum dot material is the second composition, and the composition comprising blue quantum dot material is the third composition; the concentration of the first additive in the first composition is greater than the concentration of the first additive in the second composition, and / or the concentration of the first additive in the first composition is greater than the concentration of the first additive in the third composition.

[0205] For example, a composition including red quantum dot material is a first composition, which is used to form a quantum dot light-emitting layer emitting red light after exposure and development; a composition including green quantum dot material is a second composition, which is used to form a quantum dot light-emitting layer emitting green light after exposure and development; and a composition including blue quantum dot material is a third composition, which is used to form a quantum dot light-emitting layer emitting blue light after exposure and development.

[0206] The concentration of the first additive in the first composition is greater than that in the second composition, and the concentration of the first additive in the first composition is greater than that in the third composition. That is, compared with the first composition used to form a quantum dot light-emitting layer that emits red light, when the composition is used to form a quantum dot light-emitting layer that emits green light and a quantum dot light-emitting layer that emits blue light, the concentration of the first additive in the composition can be less.

[0207] Compared to the first composition used to form a quantum dot emitting layer that emits red light, the composition contains a lower concentration of the first additive, which is sufficient to form a quantum dot emitting layer that emits green or blue light with relatively good density.

[0208] Based on the above description of the composition, the following examples are provided.

[0209] Example 1

[0210] Example 1 includes: Comparative Example 1.1, Comparative Example 1.2, and Example 1.3. Example 1 is used to demonstrate that the film formed by the composition including the first additive provided by the examples of this disclosure has good density and less quantum dot residue in non-target exposure areas.

[0211] The specific process involves coating and exposure / development experiments on different compositions to record the density of the quantum dot luminescent layer formed by different compositions and the quantum dot residue of different compositions in non-target exposure areas.

[0212] The experimental conditions were as follows: the concentration of quantum dot material in the composition was 20 g / L, the concentration of the second additive was 2 g / L, and the concentration of photoinitiator was 0.5 g / L.

[0213] The difference is that in Comparative Example 1.1, pentaerythritol tetramercaptoacetate was added as an additive to the composition; in Comparative Example 1.2, pentaerythritol tetraacrylate was added as an additive to the composition; and in Example 1.1, the first additive provided in the examples of this disclosure was added, the first additive being trimethylolpropane trimethacrylate.

[0214] Pentaerythritol tetrakis (2-mercaptoacetate) has the molecular formula C2. 13 H 20 O8S4, with a molecular weight of 432.55, has the following structural formula for pentaerythritol tetramercaptoacetate.

[0215] The English name of pentaerythritol tetraacrylate is Pentaerythritol Tetraacrylate, with the molecular formula (CH2=CHCOOCH2)4-C and a molecular weight of 352.0. The structural formula of pentaerythritol tetraacrylate is shown below.

[0216] The information about trimethylolpropane trimethacrylate is described above and will not be repeated here.

[0217] Figure 7 shows the experimental results of pure development of the composition of Comparative Example 1.1 without exposure. The concentrations of pentaerythritol tetramercaptoacetate were 0.5 g / L, 0.1 g / L and 0.05 g / L, respectively. In Figure 7, (1) corresponds to a concentration of 0.5 g / L of pentaerythritol tetramercaptoacetate, (2) corresponds to a concentration of 0.1 g / L of pentaerythritol tetramercaptoacetate, and (3) corresponds to a concentration of 0.1 g / L of pentaerythritol tetramercaptoacetate.

[0218] As shown in Figure 7, when the concentration of pentaerythritol tetramercaptoacetate is 0.5 g / L, the substrate after direct development without exposure is pink, indicating that there is a large amount of quantum dot material on the substrate surface. When the concentration of pentaerythritol tetramercaptoacetate is 0.5 g / L and 0.05 g / L, the substrate after direct development without exposure is purplish-red. That is to say, even when the concentration of pentaerythritol tetramercaptoacetate is reduced to 0.05 g / L, a large amount of quantum dot residue will still be generated. Therefore, pentaerythritol tetramercaptoacetate is not very effective as a crosslinking material for quantum dot materials.

[0219] Figure 8 shows scanning electron microscope (SEM) images of the composition of Comparative Example 1.2 after exposure and development, and after development without exposure. The exposure wavelength was 365 nm and the exposure dose was 300 mJ / cm². 2The concentrations of pentaerythritol tetraacrylate were 0 g / L, 0.5 g / L, and 3 g / L, respectively. In Figure 8, (1), (2), and (3) are scanning electron microscope (SEM) images of the target exposure area after exposure and development, where (1) corresponds to a pentaerythritol tetraacrylate concentration of 0 g / L, (2) corresponds to a pentaerythritol tetraacrylate concentration of 0.5 g / L, and (3) corresponds to a pentaerythritol tetraacrylate concentration of 3 g / L. (4), (5), and (6) are SEM images of the non-target exposure area after unexposed development, where (4) corresponds to a pentaerythritol tetraacrylate concentration of 0 g / L, (5) corresponds to a pentaerythritol tetraacrylate concentration of 0.5 g / L, and (6) corresponds to a pentaerythritol tetraacrylate concentration of 3 g / L.

[0220] As can be seen from Figure 8, although the amount of quantum dot residue in the non-target exposure area did not increase with the addition of pentaerythritol tetraacrylate, the density of the film gradually decreased with the increase of pentaerythritol tetraacrylate concentration, compared with the density of the target exposure area.

[0221] This is because the multi-branched acryloyloxy molecules compete with the ligands on the surface of the quantum dot. Under ultraviolet light, some of the photoinitiator is consumed, and the resulting free radicals are highly reactive, leading to self-crosslinking between the multi-branched molecules and failing to connect multiple quantum dot materials. At the same time, the number of photoinitiators acting on the quantum dot materials is reduced, ultimately resulting in a poorer crosslinking effect of the quantum dot materials, which in turn reduces the density of the film.

[0222] Figure 9 shows scanning electron microscope (SEM) images of the composition of Example 1.3 after exposure and development, and after development without exposure. The exposure wavelength was 365 nm, and the exposure dose was 200 mJ / cm². 2 The amounts of trimethylolpropane trimethacrylate added were 0 g / L and 0.5 g / L, respectively. In Figure 9, (1) and (2) are scanning electron microscope images of the target exposure area after exposure and development, where (1) corresponds to a concentration of 0 g / L of trimethylolpropane trimethacrylate, and (2) corresponds to a concentration of 0.5 g / L of trimethylolpropane trimethacrylate. (3) and (4) are scanning electron microscope images of the non-target exposure area after unexposed development, where (3) corresponds to a concentration of 0 g / L of trimethylolpropane trimethacrylate, and (4) corresponds to a concentration of 0.5 g / L of trimethylolpropane trimethacrylate.

[0223] As can be seen from Figure 9, the amount of quantum dots remaining in the non-target exposure area did not increase after the addition of trimethylolpropane trimethacrylate, but the density of the target exposure area improved.

[0224] This is because, based on the existing cross-linking of quantum dot materials through the first ligand group, trimethylolpropane trimethacrylate (TMT) causes more quantum dots to cross-link, thus increasing the film density. One reason for the better film density is that the methyl groups attached to the carbon-carbon double bonds in TMT have an electron-donating effect, which can compensate for the difference in electron cloud density on the double bonds caused by the ester bonds (ester bonds have an electron-withdrawing effect). The carbon-carbon double bonds also stabilize free radical activity. During exposure, the double bonds of the first ligand group open and undergo free radical polymerization. After the addition of TMT, the double bonds of TMT open, increasing the cross-linking sites, thus improving the film density.

[0225] Therefore, as can be seen from Example 1, the film formed by the composition including the first additive provided by the embodiments of this disclosure has good density and less quantum dot residue in non-target exposure areas.

[0226] Example 2

[0227] Example 2 demonstrates that when the concentration of the first additive in the composition is less than 2 g / L, the film density in the target exposure area is better.

[0228] The experimental conditions were as follows: the concentration of quantum dot material in the composition was 20 g / L, the concentration of the second additive was 2 g / L, the concentration of photoinitiator was 0.5 g / L, and the first additive was trimethylolpropane trimethacrylate.

[0229] The difference is that the concentrations of trimethylolpropane trimethacrylate in the compositions are 0 g / L, 0.25 g / L, 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L and 3 g / L, respectively.

[0230] Figure 10 is a scanning electron microscope image of the composition of Example 2 after exposure and development. The exposure wavelength was 365 nm and the exposure dose was 200 mJ / cm². 2 In Figure 10, (1) corresponds to a concentration of 0 g / L for trimethylolpropane trimethacrylate, (2) corresponds to a concentration of 0.25 g / L for trimethylolpropane trimethacrylate, (3) corresponds to a concentration of 0.5 g / L for trimethylolpropane trimethacrylate, (4) corresponds to a concentration of 1 g / L for trimethylolpropane trimethacrylate, (5) corresponds to a concentration of 1.5 g / L for trimethylolpropane trimethacrylate, (6) corresponds to a concentration of 2 g / L for trimethylolpropane trimethacrylate, and (7) corresponds to a concentration of 3 g / L for trimethylolpropane trimethacrylate.

[0231] As shown in Figure 10, the density of the exposed area gradually improves after exposure and development as the concentration of trimethylolpropane trimethacrylate (TMT) increases from 0 to 1.5 g / L. However, as the concentration continues to increase, the film density of the exposed area gradually decreases. At a TMT concentration of 2 g / L, the film density is close to that at a TMT concentration of 0 g / L. At a TMT concentration of 3 g / L, the film density is lower than that at a TMT concentration of 0 g / L.

[0232] Therefore, when the concentration of the first additive in the composition is less than 2 g / L, the film density in the target exposure area is better.

[0233] Example 3

[0234] Example 3 is used to demonstrate that changes in the R2 structure in Formula I of the first additive have little effect on the film density of the target exposure area.

[0235] The experimental conditions were as follows: the concentration of quantum dot material in the composition was 20 g / L, the concentration of the second additive was 2 g / L, and the concentration of photoinitiator was 0.5 g / L.

[0236] The difference lies in the composition used as a control, which does not contain the first additive. The other compositions use bisphenol A-dimethacrylate, ethylene glycol dimethacrylate, and dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate) as the first additives, respectively, with equal concentrations of the first additives. All three materials have methacryloyloxy groups at both ends, but the composition of the portions connecting the two methacryloyloxy groups differs.

[0237] For information on bisphenol A-dimethacrylate, ethylene glycol dimethacrylate, and dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate), please refer to the above content and it will not be repeated here.

[0238] Figure 11 is a scanning electron microscope image of the composition of Example 3 after exposure and development. The exposure wavelength was 365 nm and the exposure dose was 200 mJ / cm. 2 In Figure 11, (1) the corresponding composition does not contain the first additive, (2) the corresponding composition has the first additive of bisphenol A-dimethacrylate, (3) the corresponding composition has the first additive of ethylene glycol dimethacrylate, and (4) the corresponding composition has the first additive of dithiodi(ethane-2,1-di)bis(2-methacrylate).

[0239] As shown in Figure 11, compared with the control group without the first additive, the film density of the composition with the above three materials after exposure and development is improved. Moreover, the film density after exposure and development with the above three materials is quite consistent, and there is no difference due to the change in the composition of the intermediate part.

[0240] Furthermore, compared to the bibranched first additive provided in Example 3, the tribranched first additive (trimethylolpropane trimethacrylate) provided in Example 2 resulted in a film with better density. This further demonstrates that the first additive can improve the density of the film, and the more first groups in the first additive, the better the density of the film.

[0241] Example 4

[0242] Example 4 demonstrates that having 10 or less atoms in the first main chain between the first groups in the first additive is beneficial for improving the density of the film. When the number of atoms in the first main chain between the first groups in the first additive is greater than 10, the density of the film decreases.

[0243] The experimental conditions were as follows: the concentration of quantum dot material in the composition was 20 g / L, the concentration of the second additive was 2 g / L, and the concentration of photoinitiator was 0.5 g / L.

[0244] The difference lies in the composition used as a control, which does not contain the first additive. The other compositions use ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate as the first additives, respectively, with equal concentrations of each additive. All three materials have methacryloyloxy groups at both ends, but the chain lengths connecting the two methacryloyloxy groups differ, meaning the number of atoms between the two methacryloyloxy groups is different.

[0245] The structures of ethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate are described above and will not be repeated here. Ethylene glycol dimethacrylate has 2 atoms between its two methacryloyl groups. Tetraethylene glycol dimethacrylate has 11 atoms between its two methacryloyl groups.

[0246] The average molecular weight of polyethylene glycol dimethacrylate is 736. The number of atoms between the two methacryloyloxy groups in polyethylene glycol dimethacrylate is greater than 11. The structural formula of polyethylene glycol dimethacrylate is as follows.

[0247] Figure 12 is a scanning electron microscope image of the composition of Example 4 after exposure and development. The exposure wavelength was 365 nm and the exposure dose was 200 mJ / cm. 2In Figure 12, (1) the corresponding composition does not contain the first additive, (2) the corresponding composition has ethylene glycol dimethacrylate as the first additive, (3) the corresponding composition has tetraethylene glycol dimethacrylate as the first additive, and (4) the corresponding composition has polyethylene glycol dimethacrylate as the first additive.

[0248] As can be seen from Figure 12, the density of the film gradually decreases as the chain length of the middle part increases, and for polyethylene glycol dimethacrylate, it is lower than the density of the film in the control figure without additives.

[0249] Therefore, for the first additive, the fewer atoms between the two methacryloyloxy groups, the better the density of the film formed; that is, the shorter the chain length, the better the density of the film formed.

[0250] Example 5

[0251] Example 5 demonstrates that including a second group, as shown in Formula III, at the end of the first ligand group furthest from the quantum dot bulk can improve the stability of the quantum dot material.

[0252] Example 5 includes: Example 5.1 and Comparative Example 5.2. In Example 5.1, a portion of the second ligand group, such as the oleic acid ligand, on the surface of the quantum dot body is replaced by MMES, i.e., the quantum dot material of Example 5.1 includes: a quantum dot body and an oleic acid ligand and an MMES ligand coordinated to the quantum dot body; in Comparative Example 5.2, a portion of the second ligand group, such as the oleic acid ligand, on the surface of the quantum dot body is replaced by 4-(2-(acryloyloxy)ethoxy)-4-oxobutyric acid, i.e., the quantum dot material of Comparative Example 5.2 includes: a quantum dot body and an oleic acid ligand and a 4-(2-(acryloyloxy)ethoxy)-4-oxobutyric acid ligand coordinated to the quantum dot body.

[0253] The structure of MMES is shown below.

[0254] The structural formula of 4-(2-(acryloyloxy)ethoxy)-4-oxobutyric acid is shown below.

[0255] A comparison of the structural formulas of MMES and 4-(2-(acryloyloxy)ethoxy)-4-oxobutyric acid reveals that the difference between the two ligands is that MMES has an electron-donating group attached to its double bond, which is a methyl group.

[0256] The quantum dot materials of Example 5.1 and Comparative Example 5.2 were placed in the dark. Figure 13 shows the physical images of Example 5.1 and Comparative Example 5.2 after being placed in the dark. In Figure 13, (1) is a physical image of the quantum dot material solution of Comparative Example 5.2 after one day. It can be seen from the figure that the color of the quantum dot material solution of Comparative Example 5.2 is brownish-red with a milky white tinge. The solution has become turbid and opaque, indicating that the quantum dot material has undergone a chemical change.

[0257] Figure 13(2) shows the physical image of the quantum dot material solution of Example 5.1 after 4 months. As can be seen from the figure, the solution of the quantum dot material of Example 5.1 is dark brownish-red and the solution is translucent, indicating that the solution can be stably stored for more than 4 months and the quantum dot material is still stable.

[0258] This is because acryloyloxy ligands are more reactive than methacryloyloxy ligands, and quantum dot materials containing acryloyloxy ligands cannot be stored stably for long periods. In contrast, quantum dot materials using methacryloyloxy ligands can be stored stably for extended periods.

[0259] As shown in FIG14, an embodiment of the present disclosure also provides a light-emitting substrate 100, the light-emitting substrate 100 including a plurality of light-emitting devices 10 disposed on a substrate 101, each of the plurality of light-emitting devices 10 including: a first electrode 102, a second electrode 103, and a light-emitting pattern 104 disposed between the first electrode 102 and the second electrode 103.

[0260] For example, the light-emitting substrate 100 includes a substrate 101 and a pixel defining layer 110 located on the substrate 101. The pixel defining layer 110 is provided with a plurality of openings Q, and a plurality of light-emitting devices 10 are provided in a one-to-one correspondence with the plurality of openings K.

[0261] For example, the substrate 101 may be an array substrate, which includes a thin film transistor (TFT) array. For instance, the array substrate includes a substrate, and an active layer, a gate insulating layer, a gate metal layer, an interlayer insulating layer, a source / drain metal layer, and a planarization layer sequentially stacked on the substrate. A first electrode layer 102a is disposed on the side of the planarization layer away from the substrate, and the first electrode layer 102a includes a plurality of first electrodes 102. Alternatively, the substrate 101 may also be a substrate substrate, and the light-emitting substrate 100 may further include other film layers disposed between the substrate 101 and the first electrode layer 102a, such as an active layer, a gate insulating layer, a gate metal layer, an interlayer insulating layer, a source / drain metal layer, and a planarization layer.

[0262] For example, the first electrode 102 is one of the anode and the cathode, and the second electrode 103 is the other of the anode and the cathode.

[0263] For example, the plurality of light-emitting devices 10 include: a first light-emitting device Q1, a second light-emitting device Q2 and a third light-emitting device Q3; the first light-emitting device Q1 is configured to emit red light, the second light-emitting device Q2 is configured to emit green light and the third light-emitting device Q3 is configured to emit blue light.

[0264] For example, the light-emitting pattern 104 includes: light-emitting pattern 1041, light-emitting pattern 1042, and light-emitting pattern 1043. The first light-emitting device Q1 includes light-emitting pattern 1041, the second light-emitting device Q2 includes light-emitting pattern 1042, and the third light-emitting device Q3 includes light-emitting pattern 1043.

[0265] In some examples, the light-emitting pattern 1041 of the first light-emitting device Q1 is formed by chemical bonding of the first additive of the first composition and the red quantum dot material under preset conditions; the light-emitting pattern 1042 of the second light-emitting device Q2 is formed by chemical bonding of the first additive of the second composition and the green quantum dot material under preset conditions; and the light-emitting pattern 1043 of the third light-emitting device Q3 is formed by chemical bonding of the first additive of the third composition and the blue quantum dot material under preset conditions.

[0266] That is, the first composition includes red quantum dot material, which is used to form a red light emission pattern 1041 after exposure and development; the second composition includes green quantum dot material, which is used to form a green light emission pattern 1042 after exposure and development; and the third composition includes blue quantum dot material, which is used to form a blue light emission pattern 1043 after exposure and development.

[0267] The concentration of the first additive in the first composition is greater than that in the second composition, and the concentration of the first additive in the first composition is greater than that in the third composition.

[0268] Compared to the first composition used to form a quantum dot emitting layer that emits red light, the composition contains a lower concentration of the first additive, which is sufficient to form a quantum dot emitting layer that emits green or blue light with relatively good density.

[0269] For example, the material of the luminescent pattern 104 includes any of the structures shown in Formula VII.

[0270] R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; n1 is a positive integer greater than or equal to 2.

[0271] R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxyl, alkoxy, and alkyl; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl.

[0272] For an introduction to R1, R2, R3, R4, R5, and R6, please refer to the above content; it will not be repeated here.

[0273] In this example, a cross-linked structure is formed by connecting a first ligand group to the quantum dot body, and the first ligand group includes a second group. Multiple first ligand groups can be connected to the quantum dot body, and each first ligand group can include multiple second groups. Each second group on the quantum dot body can be cross-linked with the first group of the first additive to form a cross-linked network.

[0274] In some examples, the material of the luminescent pattern 104 also includes any of the structures shown in general formula VIII.

[0275] R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxyl, alkoxy, and alkyl groups; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl. n2 is a positive integer greater than or equal to 1.

[0276] For an introduction to R4, R5, and R6, please refer to the above content; it will not be repeated here.

[0277] Among them, two R4s are the same or different; two R5s are the same or different; two R6s are the same or different.

[0278] In this example, a cross-linked structure is formed by attaching a first ligand group to a quantum dot body and the first ligand group including a second group. When multiple first ligand groups are attached to each quantum dot body and / or multiple second groups are attached to each first ligand group, each second group on the quantum dot body can react to form a cross-linked structure.

[0279] For example, the chain length after cross-linking between two adjacent quantum dot bodies is less than 40.

[0280] By ensuring that the chain length between two adjacent quantum dot bodies is less than 40, the problem of excessively long chain lengths between adjacent quantum dot bodies affecting charge injection and thus the performance of electroluminescent devices can be effectively avoided.

[0281] In some examples, the material of the luminescent pattern 104 also includes any of the structures shown in general formula IX.

[0282] Among them, -CR 61 R 62 R 63 The group remaining after removing one hydrogen atom from R6.

[0283] The photoinitiator in the composition is linked to the first ligand group of the quantum dot material via a hydrocarbon insertion reaction, as shown in the following specific reaction.

[0284] For an introduction to R4, R5, R6, R7, R8, and n3, please refer to the above content; it will not be repeated here.

[0285] For example, the structure of a photoinitiator is shown below.

[0286] For example, the first ligand group of the quantum dot material is the structure after MMES is connected to the quantum dot body, and the chemical formula for reacting with the above photoinitiator is shown below.

[0287] In some examples, the photoinitiator in the composition is linked to a first ligand group of the quantum dot material via a hydrocarbon insertion reaction, and the composition also includes a reaction of the photoinitiator with a second group of the first ligand group via a hydrocarbon insertion reaction.

[0288] For example, the first ligand group is MMES, and the second group is methacryloyloxy. The methyl group (-CH3) in methacryloyloxy can react with the photoinitiator through a hydrocarbon insertion reaction to achieve the connection between the photoinitiator and the quantum dot material.

[0289] In other examples, the photoinitiator in the composition can be linked to a second ligand group of the quantum dot material via a hydrocarbon insertion reaction.

[0290] In some embodiments, as shown in FIG14, the light-emitting device 10 includes: a first electrode 102, a hole injection layer (not shown in the figure), a hole transport layer (not shown in the figure), a light-emitting pattern 104, an electron transport layer (not shown in the figure), and a second electrode 103 stacked together.

[0291] For example, the material of the hole injection layer may include PEDOT (poly(3,4-ethylenedioxythiophene)), PSS4083 (polystyrene sulfonate), or other compounds suitable for hole injection, and there are no limitations herein.

[0292] For example, the material of the hole transport layer may include poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), or polyvinylcarbazole (PVK), etc., and is not limited herein.

[0293] For example, the electron transport layer may include a nanoparticle film of zinc oxide or zinc magnesium oxide or a sol-gel film, etc., and is not limited herein.

[0294] By setting up a hole injection layer, a hole transport layer, and an electron transport layer, the carrier transport performance of the light-emitting device 10 can be improved, thereby enhancing the light-emitting performance of the light-emitting device 10.

[0295] As shown in Figures 14 and 15, embodiments of this disclosure also provide a method for preparing a light-emitting substrate, the method comprising steps T1 to T4.

[0296] T1. A first electrode 102 is formed on one side of the substrate 101.

[0297] For example, the first electrode 102 is the anode, and the anode material is ITO (indium tin oxide).

[0298] For example, an ITO substrate is provided, which is cleaned sequentially with deionized water and isopropanol, dried with a nitrogen gun, and then baked for later use.

[0299] T2. A composition is coated on the side of the first electrode 102 away from the substrate 101; wherein the composition comprises: a quantum dot material and a first additive, the first additive being selected from any of the structures shown in general formula I.

[0300] For an introduction to the first additive and quantum dot materials with the structure shown in Formula I, please refer to the above content, and it will not be repeated here.

[0301] T3. Expose the target area, which is used to form the luminescent pattern 104.

[0302] T4. Development, removing the composition from areas other than the target area, forming a luminescent pattern 104; wherein the material of the luminescent pattern 104 includes any one of the structures shown in general formula VII.

[0303] For an introduction to the structure shown in general formula VII, please refer to the above content, and it will not be repeated here.

[0304] The following example illustrates the method for fabricating the light-emitting substrate described in steps T1 to T4 above.

[0305] S1. As shown in Figure 16, a substrate 101 is provided, and a first electrode layer 102a is formed on one side of the substrate 101. The first electrode layer 102a includes a plurality of first electrodes 102. A pixel defining layer 110 is formed on the side of the first electrode layer 102a away from the substrate 101. The pixel defining layer 110 is provided with a plurality of openings K, and the plurality of openings K correspond one-to-one with the plurality of first electrodes 102.

[0306] For example, in the structure formed in this step, each opening K exposes a first electrode 102.

[0307] For example, a hole injection layer is formed on the side of the first electrode 102 away from the substrate 101; for example, the hole injection layer is formed by a spin coating process or a vapor deposition process, and the material of the hole injection layer includes PEDOT.

[0308] For example, a hole transport layer is formed on the side of the hole injection layer away from the substrate 101; for example, the hole transport layer is formed by a spin coating process or a vapor deposition process, and the material of the hole transport layer includes TFB.

[0309] S2. As shown in FIG16, a first initial composition layer 104A is formed on the side of the first electrode 102 away from the substrate 101.

[0310] It is understood that when the light-emitting substrate 100 includes a hole transport layer, a first initial composition layer 104A is formed on the side of the hole transport layer away from the substrate 101.

[0311] For example, the material of the first initial composition layer 104A includes the first composition; for example, the first composition includes red quantum dot material. The description of the first composition is as described above and will not be repeated here.

[0312] For example, the first initial composition layer 104A is formed by spin coating.

[0313] S3. As shown in Figure 16, the first target exposure area M11 is exposed; the first target exposure area M11 is the area where the first light-emitting device Q1 is formed.

[0314] For example, a mask is used to expose the first target exposure area M11 at a wavelength of 365 nm and an exposure dose of 200 mJ / cm². 2 .

[0315] S4. As shown in Figure 16, development is performed to remove the portion of the first initial composition layer 104A located outside the first target exposure area M11, resulting in a luminescent pattern 1041.

[0316] For example, the developer may include PGME.

[0317] The area outside the first target exposure area M11 is the non-target exposure area.

[0318] S5. As shown in Figure 16, a second initial composition layer 104B is formed on the side of the light-emitting pattern 1041 away from the substrate 101.

[0319] For example, the material of the second initial composition layer 104B includes the second composition; for example, the second composition includes green quantum dot material. The description of the second composition is as described above and will not be repeated here.

[0320] For example, the second initial composition layer 104B is formed by spin coating.

[0321] S6. As shown in Figure 16, expose the second target exposure area M22; the second target exposure area M22 is the area where the second light-emitting device Q2 is formed.

[0322] For example, a mask is used to expose the second target exposure area M22 at a wavelength of 365nm and an exposure dose of 200mJ / cm². 2 .

[0323] S7. As shown in Figure 16, development is performed to remove the portion of the second initial composition layer 104B located outside the second target exposure area M22, resulting in a luminescent pattern 1042.

[0324] For example, the developer may include PGME.

[0325] The area outside the second target exposure area M22 is the non-target exposure area.

[0326] S8. As shown in Figure 17, a third initial composition layer 104C is formed on the side of the light-emitting pattern 1042 away from the substrate 101.

[0327] For example, the material of the third initial composition layer 104C includes the third composition; for example, the third composition includes blue quantum dot material. The description of the third composition is as described above and will not be repeated here.

[0328] For example, the third initial composition layer 104C is formed by spin coating.

[0329] S9. As shown in Figure 17, expose the third target exposure area M33; the third target exposure area M33 is the area where the third light-emitting device Q3 is formed.

[0330] For example, a mask is used to expose the third target exposure area M33 at a wavelength of 365 nm and an exposure dose of 200 mJ / cm². 2 .

[0331] S10, as shown in Figure 17, development is performed to remove the portion of the third initial composition layer 104C located outside the third target exposure area M33, resulting in a luminescent pattern 1043.

[0332] For example, the developer may include PGME.

[0333] The area outside the third target exposure area M33 is the non-target exposure area.

[0334] For example, an electron transport layer is formed on the side of the light-emitting pattern 1043 away from the substrate 101; for example, the electron transport layer is formed by a spin coating process or a vapor deposition process, and the material of the electron transport layer includes zinc oxide.

[0335] As exemplarily shown in FIG14, a second electrode 103 is formed on the side of the electron transport layer away from the substrate 101. For example, the material of the second electrode 103 includes aluminum. Then, encapsulation is performed to obtain the light-emitting substrate 100.

[0336] Through the above steps S1 to S10, a quantum dot light-emitting layer of the light-emitting substrate 100 is formed using the composition provided in the embodiments of this disclosure. The quantum dot light-emitting layer has a high density and fewer quantum dots remaining in the non-target exposure area.

[0337] As shown in FIG18, an embodiment of the present disclosure also provides a light-emitting device 1000, which includes a light-emitting substrate 100 as described in any of the above embodiments.

[0338] Of course, the light-emitting device 1000 may also include other components, such as a driving circuit for providing electrical signals to the light-emitting substrate 100 to drive the light-emitting substrate 100 to emit light. This circuit may be called a control circuit. The light-emitting device 1000 may also include a circuit board and / or a driving chip electrically connected to the light-emitting substrate 100.

[0339] In some embodiments, the light-emitting device 1000 can be an illumination device, in which case the light-emitting device 1000 serves as a light source to achieve the illumination function. For example, the light-emitting device 1000 can be a backlight module in a liquid crystal display device, a lamp for internal or external illumination, or various signal lights, etc.

[0340] In other embodiments, the light-emitting device 1000 can be a display device, in which case the light-emitting substrate 100 is a display substrate used to display images (i.e., screens). The light-emitting device 1000 can include a display or a product containing a display. The display can be a flat panel display (FPD), a microdisplay, etc. Based on whether the user can see the back of the display, the display can be a transparent display or an opaque display. Based on whether the display can be bent or rolled, the display can be a flexible display or a regular display (which can be called a rigid display). Examples of products containing displays include: computer monitors, televisions, billboards, laser printers with display functions, telephones, mobile phones, personal digital assistants (PDAs), laptops, digital cameras, portable camcorders, viewfinders, vehicles, large-area walls, theater screens, or stadium signs, etc. Figure 18 illustrates this using a mobile phone as an example of the light-emitting device 1000.

[0341] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

A composition comprising: Quantum dot material and a first additive, wherein the first additive is selected from any one of the structures shown in general formula I below; Wherein, R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon and quaternary carbon; n1 is a positive integer greater than or equal to 2; Under preset conditions, the first additive is chemically bonded to the quantum dot material. The composition according to claim 1, wherein, The first additive includes a first group, which is selected from any one of the groups shown in general formula II below; In the first additive, any two first groups have a first main chain connecting the two first groups, wherein the number of atoms in the first main chain between at least two first groups is less than or equal to 10. The composition according to claim 1 or 2, wherein, In the composition, the concentration of the first additive is less than 2 g / L. The composition according to any one of claims 1 to 3, wherein, The first additive includes at least one of: trimethylolpropane trimethacrylate, bisphenol A-dimethacrylate, ethylene glycol dimethacrylate, dithiodimethylbis(ethane-2,1-diyl)bis(2-methacrylate) and tetraethylene glycol dimethacrylate. The composition according to any one of claims 1 to 3, wherein, The first additive also includes: aromatic amine groups. The composition according to any one of claims 1 to 5, wherein, The quantum dot material comprises: a quantum dot body and a first ligand group coordinated and connected to the quantum dot body; the end of the first ligand group away from the quantum dot body comprises: a second group; the second group is selected from any one of the groups shown in General Formula III below; R5 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl. The composition according to claim 6, wherein, The first ligand group includes a coordinating group, which is coordinated to the quantum dot body, and the coordinating group includes at least one of carboxyl, thiol and amino groups. The composition according to claim 7, wherein, The quantum dot material includes any one of the structures shown in general formula IV below; Wherein, R4 is the coordinating group; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted arylene, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused arylene; n2 is a positive integer greater than or equal to 1; n3 is a positive integer greater than or equal to 1; The quantum dot itself. The composition according to claim 8, wherein, R6 includes a second main chain connecting R4 and the second group, wherein the number of atoms in the second main chain is less than or equal to 15. The composition according to claim 9, wherein, R6 also includes at least one of ester bonds and ether bonds. The composition according to any one of claims 6 to 10, wherein, The quantum dot material further includes a second ligand group coordinated to the quantum dot body, the second ligand group comprising a coordinating group; the second ligand group is different from the first ligand group. The composition according to claim 11, wherein, The ratio of the sum of the mass of the first ligand group and the mass of the second ligand group to the mass of the quantum dot material ranges from 3 to 10. The composition according to any one of claims 6 to 12, wherein, The quantum dot body includes at least one of the following: group II-VI semiconductor compounds, group III-V semiconductor compounds, group III-VI semiconductor compounds, group I-III-VI semiconductor compounds, group IV-VI semiconductor compounds, and group IV elements or compounds. The composition according to any one of claims 1 to 13 further comprises: Photoinitiator; Under the influence of light and a photoinitiator, the first additive is chemically bonded to the quantum dot material. The composition according to claim 14, wherein, The photoinitiator is selected from any one of the structures shown in general formula V below; Wherein, R7 is selected from any one of substituted or unsubstituted alkyl groups of C1 to C10, substituted or unsubstituted cycloalkyl groups of C3 to C10, and substituted or unsubstituted heterocycloalkyl groups of C3 to C10; R8 includes any one of ester bonds and ether bonds, and two R8s may be the same or different; n4 is a positive integer greater than or equal to 1. The composition according to claim 14 or 15, wherein, The ratio of the mass of the photoinitiator to the mass of the quantum dot material ranges from 0.005 to 0.

15. The composition according to any one of claims 1 to 16 further comprises: The second additive includes any one of the structures shown in general formula VI below; The composition according to any one of claims 1 to 17 further comprises: The solvent includes at least one of propylene glycol methyl ether acetate, butyl lactate, ethyl 3-ethoxypropionate, and diethylene glycol monoethyl ether acetate. The composition according to any one of claims 1 to 18, wherein, The quantum dot material includes any one of red quantum dot material, green quantum dot material and blue quantum dot material; The composition comprising red quantum dot material is the first composition, the composition comprising green quantum dot material is the second composition, and the composition comprising blue quantum dot material is the third composition; the concentration of the first additive in the first composition is greater than the concentration of the first additive in the second composition, and the concentration of the first additive in the first composition is greater than the concentration of the first additive in the third composition. A light-emitting substrate, comprising: A plurality of light-emitting devices are disposed on the substrate, each of the plurality of light-emitting devices including: a first electrode, a second electrode, and a light-emitting pattern disposed between the first electrode and the second electrode; The material of the luminescent pattern includes any one of the structures shown in Formula VII; Wherein, R1 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R2 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; R4 is a coordinating group; R5 is selected from any one of amino, alkyl-substituted amino, hydroxy, alkoxy, and alkyl; R6 is selected from any one of substituted or unsubstituted alkylene, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkylene, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused aryl; n1 is a positive integer greater than or equal to 2; It is the quantum dot body. According to claim 20, the light-emitting substrate, wherein, The material of the luminescent pattern also includes any one of the structures shown in general formula VIII; Among them, two R4s are the same or different; two R5s are the same or different; two R6s are the same or different. The light-emitting substrate according to claim 20 or 21, wherein, The material of the luminescent pattern also includes any one of the structures shown in general formula IX; Wherein, R7 is selected from any one of substituted or unsubstituted alkyl groups of C1-C10, substituted or unsubstituted cycloalkyl groups of C3-C10, and substituted or unsubstituted heterocycloalkyl groups of C3-C10; R8 includes any one of ester bonds and ether bonds, and two R8s may be the same or different; n3 is a positive integer greater than or equal to 1; n4 is a positive integer greater than or equal to 1; -CR 61 R 62 R 63 The group remaining after removing one hydrogen atom from R6. The light-emitting substrate according to any one of claims 20 to 22, wherein, The plurality of light-emitting devices include: a first light-emitting device, a second light-emitting device, and a third light-emitting device, wherein the first light-emitting device is configured to emit red light, the second light-emitting device is configured to emit green light, and the third light-emitting device is configured to emit blue light; The light-emitting pattern of the first light-emitting device is formed by chemical bonding of the first additive of the first composition and the red quantum dot material under preset conditions; the light-emitting pattern of the second light-emitting device is formed by chemical bonding of the first additive of the second composition and the green quantum dot material under preset conditions; and the light-emitting pattern of the third light-emitting device is formed by chemical bonding of the first additive of the third composition and the blue quantum dot material under preset conditions. Wherein, the concentration of the first additive in the first composition is greater than the concentration of the first additive in the second composition, and the concentration of the first additive in the first composition is greater than the concentration of the first additive in the third composition. A method for preparing a light-emitting substrate, comprising: A first electrode is formed on one side of the substrate; The composition is coated on the side of the first electrode away from the substrate; wherein, The composition comprises: a quantum dot material and a first additive, wherein the first additive is selected from any one of the structures shown in general formula I; under preset conditions, the first additive is chemically bonded to the quantum dot material; Expose a target area, which is used to form a luminescent pattern; The composition is developed to remove areas outside the target area to form the luminescent pattern; wherein the material of the luminescent pattern includes any one of the structures shown in general formula VII; A light-emitting device, comprising: The light-emitting substrate as described in any one of claims 20 to 23; A driver chip is used to drive the light-emitting substrate to emit light.

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