Quantum dot material, preparation method, luminescent device and display panel

Abstract

The invention discloses a quantum dot material, a preparation method, a light-emitting device and a display panel, the quantum dot material comprises a quantum dot body and a quantum dot ligand, and the quantum dot body is connected with a coordination group of the quantum dot ligand through a chemical bond; the quantum dot ligand comprises a photosensitive molecule, the photosensitive molecule has a benzene ring, a coordination group and an amide group, and the coordination group is connected with the benzene ring through the amide group. In the use process, in the exposure process, amido bonds in the quantum dot ligands are broken, amino groups can be formed after the amido bonds are broken, the quantum dot ligands form a new ligand structure, quantum dot bodies in the light-emitting layer are connected with the ligand structure after exposure and development, the ligand structure comprises coordination groups and amino groups, and the quantum dot bodies in the light-emitting layer are connected with the ligand structure. The coordination group is connected with the quantum dot body through a chemical bond, a quantum dot light-emitting layer prepared from the quantum dot ligand is stable in light-emitting performance, and the display effect of a prepared display device can be guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of display, and particularly relates to a quantum dot material, a preparation method, a light-emitting device, and a display panel. Background Art

[0002] With the development of the electronics industry, there are more and more categories of electronic devices, such as computers, mobile phones, wearable devices, sports bracelets, etc. With the increase in the application scenarios of electronic devices, the functional requirements for electronic devices are also increasing. Display has become an important function of electronic devices, and the display screen has also become an important part of electronic devices. With the development of display technology, the display technology is constantly updated, and the quantum dot display technology has become a hot topic. The emission spectrum of quantum dots is adjustable, the emission spectrum is narrower, and the color gamut is wider. Therefore, quantum dot light-emitting diodes have attracted much attention in the display field and have become a promising candidate for the next-generation display technology. At present, the structure of traditional QLED devices is composed of a hole injection layer, a hole transport layer, a quantum dot light-emitting layer (QD layer), and an electron transport layer arranged in layers. In the process of preparing the quantum dot light-emitting layer, it is not convenient to perform photolithography on the quantum dot system, there are fewer QD systems that can be lithographed, and the performance of quantum dots in the QD layer is easily affected, making it difficult to meet the preparation requirements of the quantum dot light-emitting layer. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide a quantum dot material, a preparation method, a light-emitting device, and a display panel to solve the problems that in the process of preparing the quantum dot layer, it is not convenient to perform photolithography on the quantum dot system and the performance of quantum dots is easily affected.

[0004] In a first aspect, the embodiments of the present invention provide a quantum dot material, including:

[0005] A quantum dot body and a quantum dot ligand, wherein the coordination group of the quantum dot body and the quantum dot ligand is connected by a chemical bond; the quantum dot ligand includes a photosensitive molecule, and the photosensitive molecule has a benzene ring, a coordination group, and an amide group, and the coordination group is connected to the benzene ring through the amide group.

[0006] Optionally, the structural formula of the photosensitive molecule is:

[0007]

[0008] Wherein, R1, R4-R7 are selected from H, alkyl, halogen atom, -NO2, -CN, -COOH, -CHO, at least one of R1 and R4 is -NO2, R3 is selected from methylene, O, -NH-, S, and R2 is a coordination group.

[0009] Optionally, the structural formula of the photosensitive molecule is:

[0010]

[0011] Optionally, the structural formula of the photosensitive molecule includes at least one of structural formula (1) and structural formula (2):

[0012]

[0013]

[0014] Optionally, the coordination group includes:

[0015] At least one of a carboxyl group, an amino group, a mercapto group, a hydroxyl group, and a silane coupling group.

[0016] In a second aspect, an embodiment of the present invention provides a method for preparing a quantum dot material, including:

[0017] Adding an organic solvent into a reactor, and then adding an acyl chloride compound having structural formula I and a primary amine compound having structural formula II into the reactor to react under anhydrous and anaerobic conditions to prepare a quantum dot ligand;

[0018] Wherein, the reaction temperature is 0 - 30 °C, the reaction time is 1 - 4 h, and the molar ratio of the acyl chloride compound to the primary amine compound is 1 - 1.2;

[0019] Structural formula I is:

[0020]

[0021] A1 and A2 are selected from H, alkyl, -NO2, and at least one of A1 and A2 is selected as -NO2, and n is a positive integer;

[0022] Structural formula II is:

[0023]

[0024] m is a positive integer, and X1 is a coordination group;

[0025] Mixing a quantum dot solution with the quantum dot ligand to replace the ligand to prepare a quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

[0026] In a third aspect, an embodiment of the present invention provides a method for preparing a quantum dot material, including:

[0027] Adding an organic solvent into a reactor, and then adding a 2,4-dinitrofluorobenzene compound having structural formula III and a primary amine compound containing an amide group having structural formula IV into the reactor to react under light-shielded conditions to prepare a quantum dot ligand;

[0028] Among them, the reaction temperature is 70 - 95 °C, the reaction time is 1 - 3 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound containing an amide group is 1 - 1.3;

[0029] Structural formula Ⅲ is:

[0030]

[0031] B1 - B5 are selected from H, alkyl, phenyl, -NO2, and at least one of B1 and B5 is selected as -NO2;

[0032] Structural formula Ⅳ is:

[0033]

[0034] C1 is selected from H, alkyl, phenyl, and C2 is a coordination group;

[0035] The quantum dot solution is mixed with the quantum dot ligand to replace the ligand to prepare the quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

[0036] Fourthly, an embodiment of the present invention provides a light-emitting device, including:

[0037] A substrate, the pixel region of the substrate has a light-emitting layer, the light-emitting layer includes a quantum dot body and a ligand structure, the ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body through a chemical bond.

[0038] Optionally, the quantum dot body includes a first quantum dot body and a second quantum dot body, the first quantum dot body is used to emit light with a first wavelength, the second quantum dot body is used to emit light with a second wavelength, the first wavelength is different from the second wavelength, the pixel region includes a first pixel region and a second pixel region, the first quantum dot body is disposed in the first pixel region, and the second quantum dot body is disposed in the second pixel region.

[0039] Optionally, the quantum dot further includes a third quantum dot body, the pixel region further includes a third pixel region, the third quantum dot body is used to emit light with a third wavelength, the first wavelength, the second wavelength and the third wavelength are different, and the third quantum dot body is disposed in the third pixel region.

[0040] Fifthly, an embodiment of the present invention provides a method for preparing a light-emitting device, including:

[0041] Coating the quantum dot material in the above embodiment on the pixel region of the substrate, exposing the quantum dot material in the pixel region and developing to form a light-emitting layer;

[0042] Among them, the light-emitting layer includes a quantum dot body and a ligand structure. The ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body by a chemical bond.

[0043] In a sixth aspect, an embodiment of the present invention provides a display panel, including:

[0044] The light-emitting device described in the above embodiment.

[0045] The quantum dot material of the embodiment of the present invention includes a quantum dot body and a quantum dot ligand. The coordination group of the quantum dot body is connected to the quantum dot ligand by a chemical bond; the quantum dot ligand includes a photosensitive molecule, and the photosensitive molecule has a benzene ring, a coordination group and an amide group. The coordination group is connected to the benzene ring through the amide group, and the coordination group is connected to the quantum dot body by a chemical bond. During use, the coordination group in the quantum dot ligand is connected to the surface of the quantum dot body by a chemical bond, which can reduce the defects on the surface of the quantum dot body. The quantum dot material is coated on the pixel area of the substrate, and the quantum dot material in the pixel area is exposed and developed to form a light-emitting layer. During the exposure process, the amide bond in the quantum dot ligand is broken, and an amino group can be formed after the amide bond is broken. The quantum dot ligand forms a new ligand structure. After exposure and development, the quantum dot body in the light-emitting layer is connected to the ligand structure. The ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body by a chemical bond. The quantum dot light-emitting layer prepared by the quantum dot ligand in the present application has stable light-emitting performance, good light-emitting effect and high light-emitting efficiency, and can meet the requirements of the display effect. Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of a light-emitting device;

[0047] Figure 2 It is a schematic preparation process diagram of a light-emitting device.

[0048] Reference Numerals

[0049] Substrate 10; Light-emitting layer 20;

[0050] First quantum dot body 21; Second quantum dot body 22; Third quantum dot body 23;

[0051] Cathode 31; Electron injection layer 32; Electron transport layer 33;

[0052] Hole transport layer 34; Hole injection layer 35; Anode 36. Detailed Embodiments

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention can be implemented in an order different from those illustrated or described herein. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally represents an "or" relationship between the associated objects before and after.

[0055] The following combines the Figure 1 accompanying Figure 2 drawings and, as shown, through specific embodiments and their application scenarios, the quantum dot materials, preparation methods, light-emitting devices, and display panels provided by the embodiments of the present invention are described in detail.

[0056] The quantum dot material of the embodiment of the present invention includes: a quantum dot body and a quantum dot ligand, and the coordination group of the quantum dot body and the quantum dot ligand is connected by a chemical bond; the quantum dot ligand includes a photosensitive molecule, and the photosensitive molecule has a benzene ring, a coordination group, and an amide group, and the coordination group is connected to the benzene ring through the amide group. The coordination group can be a mercapto group, a carboxyl group, a hydroxyl group, or an amino group. The coordination group and the quantum dot body can be connected by a coordination bond. By means of the coordination group, the defects on the surface of the quantum dot body can be reduced, and the performance of the quantum dot body can be improved.

[0057] During the use of the quantum dot material, the coordination group in the quantum dot ligand is connected to the surface of the quantum dot body through a chemical bond, and the chemical bond can be a coordination bond. By connecting the coordination group to the surface of the quantum dot body, the defects on the surface of the quantum dot body can be reduced. The quantum dot material can be coated on the pixel area of the substrate, and the quantum dot material in the pixel area is exposed and developed to form a light-emitting layer. During the exposure process, the amide bond in the quantum dot ligand is broken, and an amino group can be formed after the amide bond is broken. The quantum dot ligand forms a new ligand structure. After exposure and development, the quantum dot body in the light-emitting layer is connected to the ligand structure. The ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body through a chemical bond. The quantum dot light-emitting layer prepared by the quantum dot ligand in the present application has stable light-emitting performance, good light-emitting effect, and high light-emitting efficiency, and can meet the display effect requirements.

[0058] In some embodiments, the structural formula of the photosensitive molecule can be:

[0059]

[0060] Among them, R1, R4-R7 can be selected from H, alkyl, halogen atom, -NO2, -CN, -COOH, -CHO. At least one of R1 and R4 is -NO2. R3 can be selected from methylene, O, -NH-, S. R2 is a coordination group. For example, R1 can be selected from H, R5-R7 can be selected from H, R4 can be -NO2, R3 can be selected from methylene or O, and R2 can be mercapto or carboxyl. R1 can be an electron-withdrawing group. For example, R1 can be selected from -NO2, -CN, -COOH, -CHO, etc., so that the bond-breaking reaction proceeds smoothly.

[0061] In some embodiments of the present invention, the structural formula of the photosensitive molecule can be:

[0062]

[0063] For example, R1 can be selected from H, R3 can be selected from methylene or O, and R2 can be carboxyl or -CH2COOH. R2 can be connected to the surface of the quantum dot body through a coordination bond, specifically as follows:

[0064]

[0065] In the process of preparing the quantum dot light-emitting layer, the quantum dot solution can be mixed with the photosensitive molecule to replace the ligand to prepare the quantum dot material, and the coated quantum dot material can be exposed by ultraviolet light irradiation. The specific reaction process can be as shown in formula (s1):

[0066]

[0067] During the ultraviolet light irradiation process, the amide bond breaks, and at the same time, a nitro reduction process also occurs. After the amide bond breaks, it forms two parts. One part is connected to the surface of the quantum dot body to change the polarity and solubility. The reduction of the nitro group can help change the polarity and solubility of the molecular structure connected to the surface of the quantum dot body. One part falls off, making the two parts formed by the photosensitive molecule more different, easier to develop cleanly without causing residue problems, and improving the performance of the quantum dot body.

[0068] In the embodiments of the present invention, the structural formula of the photosensitive molecule can include at least one of structural formula (1) and structural formula (2):

[0069]

[0070]

[0071] During the exposure process, the amide bond is broken by ultraviolet light irradiation, and at the same time, the reduction process of the nitro group also occurs. After the amide bond is broken, it becomes two parts. One part is connected to the surface of the quantum dot body to change the polarity and solubility. The reduction of the nitro group can help change the polarity and solubility of the molecular structure connected to the surface of the quantum dot body. The other part falls off, making the two parts formed by the photosensitive molecule more different and easier to develop cleanly without causing residue problems, thereby improving the performance of the quantum dot body. After illumination, the molecule with NH2 remaining on the surface of the quantum dot body is water-soluble and has a large difference from the original oil solubility. Organic solvents such as toluene and dichloromethane can be used to remove the quantum dot body that has not undergone the light exposure reaction.

[0072] Optionally, the coordination group may include at least one of carboxyl group, amino group, mercapto group, hydroxyl group, and silane coupling group. For example, the coordination group may be carboxyl group, amino group, mercapto group, or hydroxyl group. Through the coordination group, it can be connected to the surface of the quantum dot body, reducing the defects on the surface of the quantum dot body.

[0073] In the quantum dot material of the embodiment of the present invention, the quantum dot body and the coordination group in the quantum dot ligand are connected by chemical bonds.

[0074] The quantum dot body includes any one of IIB-VIA group quantum dots, IIIA-VA group quantum dots, ⅣA-VIA group quantum dots, core-shell structure quantum dots, and ABX3 type perovskite quantum dots. In the ABX3 type perovskite quantum dot, A is CH3NH3 + (methylamine), NH2CH=NH2 (formamidine), and Cs + One or more of them, B is Pb 2+ And Sn 2+ One or two of them, X is Cl - 、Br - And I - One or more of them, and the ABX3 type perovskite quantum dots include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3, and CsPbI3.

[0075] Exemplarily, the IIB-VIA group quantum dots are selected from: one or more of binary compounds such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, 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.

[0076] The IIIA-VA group quantum dots are selected from: one or more of 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.

[0077] The IVA-VIA group quantum dots are selected from: one or more of 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 not limited thereto. The IVA-VIA group quantum dots are, for example, selected from: elemental (mono-) semiconductors such as Si, Ge, or mixtures thereof; and binary semiconductor compounds such as SiC, SiGe, and mixtures thereof, but not limited thereto.

[0078] A core-shell structured quantum dot refers to a quantum dot in which one material serves as the core material and the other as the shell material. For example, a quantum dot of CdS / ZnS means that the core material of the quantum dot is CdS and the shell material is ZnS.

[0079] In some other embodiments, the quantum dot body can be other nanoscale materials, such as nanorods, nanosheets, etc. The components of other nanoscale materials can include at least one of materials such as CdS, CdSe, CdTe, ZnSe, InP, PbS, CuInS2, ZnO, CsPbCl3, CsPbBr3, CsPhI3, CdS / ZnS, CdSe / ZnS, ZnSe, InP / ZnS, PbS / ZnS, InAs, InGaAs, InGaN, GaNk, ZnTe, Si, Ge, and C.

[0080] For example, the quantum dot body can include cadmium (Cd)-free quantum dots. Cadmium (Cd)-free quantum dots are quantum dots that do not include cadmium (Cd). Cadmium (Cd) can cause serious environmental / health problems, so non-cadmium-based quantum dots can be effectively used.

[0081] During the use of quantum dot ligands, the coordination groups in the quantum dot ligands are connected to the surface of the quantum dot body through chemical bonds. By connecting the coordination groups to the surface of the quantum dot body, the defects on the surface of the quantum dot body can be reduced. During the exposure of the quantum dot material, the amide bond in the quantum dot ligand breaks. After the amide bond breaks, an amino group can be formed, and the quantum dot ligand forms a new ligand structure. After exposure and development, the quantum dot body in the light-emitting layer is connected to the ligand structure. The ligand structure includes a coordination group and an amino group. The coordination group is connected to the quantum dot body through a chemical bond. The quantum dot light-emitting layer prepared by the quantum dot material in this application has good luminescence performance and high luminescence efficiency.

[0082] The preparation method of the quantum dot material according to the embodiment of the present invention includes:

[0083] Adding an organic solvent into a reactor, and then adding an acyl chloride compound with structural formula I and a primary amine compound with structural formula II into the reactor to react under anhydrous and anaerobic conditions to prepare a quantum dot ligand; the organic solvent can include at least one of dichloromethane, benzene solvents, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and tetrahydrofuran (THF). The benzene solvents can include at least one of toluene, xylene, and benzyl alcohol. The organic solvent can be dichloromethane;

[0084] Among them, the reaction temperature can be 0 - 30°C, the reaction time can be 1 - 4h, and the molar ratio of the acyl chloride compound to the primary amine compound can be 1 - 1.2;

[0085] The structural formula I is:

[0086]

[0087] A1 and A2 can be selected from H, alkyl, -NO2, at least one of A1 and A2 is selected as -NO2, and n is a positive integer; for example, A1 is selected from H, A2 is selected as -NO2, and n is 1.

[0088] The structural formula II can be:

[0089]

[0090] Wherein, m is a positive integer, and X1 is a coordination group. The coordination group can include at least one of carboxyl group, amino group, mercapto group, hydroxyl group, and silane coupling group; for example, X1 can be a carboxyl group or a mercapto group, and m is 1.

[0091] Mix and displace the ligands of the quantum dot solution and the quantum dot ligands to prepare the quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

[0092] The reaction of the acyl chloride compound having the structural formula I and the primary amine compound having the structural formula II can be as shown in formula (s2):

[0093]

[0094] In the structural formula I, A1 is selected from H, A2 is selected as -NO2, and n is 1. In the structural formula II, X1 is a carboxyl group and m is 1. The reaction of the structural formula I and the structural formula II can be as shown in formula (s3):

[0095]

[0096] In the process of preparing the quantum dot light-emitting layer, the quantum dot solution and the prepared quantum dot ligands can be mixed and displaced to prepare the quantum dot material, and the coated quantum dot material is exposed by ultraviolet light irradiation. The specific reaction process can be as shown in formula (s4):

[0097]

[0098] During the exposure process, the amide bond is broken by ultraviolet light irradiation, and at the same time, the reduction process of the nitro group also occurs. After the amide bond is broken, it forms two parts. One part is connected to the surface of the quantum dot body to change the polarity and solubility. The reduction of the nitro group can help change the polarity and solubility of the molecular structure connected to the surface of the quantum dot body. The other part falls off, making the two parts formed by the photosensitive molecule more different, easier to develop cleanly without causing residue problems, and improving the performance of the quantum dot body.

[0099] The preparation method of the quantum dot material according to the embodiment of the present invention includes:

[0100] Add an organic solvent into a reactor, and then add a 2,4-dinitrofluorobenzene compound with structural formula Ⅲ and a primary amine compound containing an amide group with structural formula Ⅳ into the reactor to react under light shielding conditions to prepare a quantum dot ligand; the organic solvent may include at least one of alcohols, dichloromethane, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and tetrahydrofuran (THF). For example, the alcohols may include at least one of methanol, ethanol, propanol, and aromatic alcohols, and the organic solvent may be ethanol;

[0101] Among them, the reaction temperature may be 70-95 °C, the reaction time may be 1-3 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound containing an amide group may be 1-1.3;

[0102] The structural formula Ⅲ is:

[0103]

[0104] B1-B5 are selected from H, alkyl, phenyl, -NO2, and at least one of B1 and B5 is selected as -NO2;

[0105] For example, the structural formula Ⅲ may be:

[0106]

[0107] The structural formula Ⅳ may be:

[0108]

[0109] C1 may be selected from H, alkyl, phenyl, and C2 may be a coordination group. For example, C1 may be selected from H or alkyl, and C2 may be -CH2COOH, carboxyl group, amino group, mercapto group, or hydroxyl group.

[0110] Mix the quantum dot solution with the quantum dot ligand to displace the ligand to prepare a quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

[0111] The reaction of the 2,4-dinitrofluorobenzene compound with structural formula Ⅲ and the primary amine compound containing an amide group with structural formula Ⅳ may be as shown in formula (s5):

[0112]

[0113] B2, B4, and B5 are selected from H, B1 and B3 are selected as -NO2, C1 may be selected from H, and C2 may be -CH2COOH. The specific reaction may be as shown in formula (s6):

[0114]

[0115] The -COOH in C2 is connected to the surface of the quantum dot body through chemical bonds. In the process of preparing the quantum dot light-emitting layer, the quantum dot solution can be mixed with the prepared quantum dot ligand to displace the ligand to prepare the quantum dot material. The coated quantum dot material is exposed by ultraviolet light irradiation. The specific reaction process after exposure can be as shown in formula (s7):

[0116]

[0117] During the exposure process, the amide bond is broken after ultraviolet light irradiation, and at the same time, the reduction process of the nitro group also occurs. After the amide bond is broken, it forms two parts. One part is connected to the surface of the quantum dot body to change the polarity and solubility, making the two parts formed by the photosensitive molecules more different, easier to develop cleanly without causing residue problems, and improving the performance of the quantum dot body.

[0118] The light-emitting device according to the embodiment of the present invention, such as Figure 1 shown, the light-emitting device may include: a substrate 10. The pixel region of the substrate 10 has a light-emitting layer 20. The light-emitting layer 20 includes a quantum dot body and a ligand structure. The ligand structure includes a coordination group and an amino group. The coordination group is connected to the quantum dot body through a chemical bond.

[0119] During the preparation of the light-emitting layer, the quantum dot material in the pixel region is exposed and developed to form the light-emitting layer. After exposure, the amide bond in the quantum dot ligand is broken. After the amide bond is broken, an amino group is formed, and the quantum dot ligand forms a new ligand structure. After exposure and development, the quantum dot body in the light-emitting layer is connected to the ligand structure. The ligand structure includes a coordination group and an amino group. The coordination group is connected to the quantum dot body through a chemical bond. The quantum dot light-emitting layer prepared by the quantum dot ligand in the present application has good light-emitting performance and high light-emitting efficiency, and can meet the requirements of the display effect.

[0120] In some embodiments, the quantum dot body may include a first quantum dot body 21 and a second quantum dot body 22. The first quantum dot body 21 is used to emit light with a first wavelength, and the second quantum dot body 22 is used to emit light with a second wavelength. The first wavelength is different from the second wavelength. The pixel region includes a first pixel region and a second pixel region. The first quantum dot body 21 is disposed in the first pixel region, and the second quantum dot body 22 is disposed in the second pixel region.

[0121] Optionally, the quantum dot body may further include a third quantum dot body 23, and the pixel region may further include a third pixel region. The third quantum dot body 23 is used to emit light with a third wavelength. The first wavelength, the second wavelength, and the third wavelength are different. The third quantum dot body 23 is disposed in the third pixel region.

[0122] In an embodiment of the present invention, the light-emitting device may further include a cathode 31, an electron transport layer 33, a hole transport layer 34, a hole injection layer 35, and an anode 36. The cathode 31 is disposed on the substrate 10, and the cathode 31, the electron transport layer 33, the light-emitting layer 20, the hole transport layer 34, the hole injection layer 35, and the anode 36 are stacked. The light-emitting device may further include an electron injection layer 32, and the cathode 31, the electron injection layer 32, the electron transport layer 33, the light-emitting layer 20, the hole transport layer 34, the hole injection layer 35, and the anode 36 are stacked.

[0123] A method for manufacturing a light-emitting device according to an embodiment of the present invention includes:

[0124] Coating the quantum dot material in the above embodiment on the pixel region of the substrate, exposing and developing the quantum dot material in the pixel region to form a light-emitting layer; wherein, the light-emitting layer includes a quantum dot body and a ligand structure, and the ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body through a chemical bond. The light-emitting device prepared by the above method has good light-emitting performance and high light-emitting efficiency of the quantum dot light-emitting layer, and can meet the requirements of display effects.

[0125] As Figure 2 shown, the manufacturing process of the light-emitting device may include the following steps:

[0126] Preparing a substrate 10, a bottom electrode, and an electron transport layer 33;

[0127] Preparing a patterned bottom electrode on the glass substrate in advance. The bottom electrode may be a cathode, and the cathode may be indium tin oxide (ITO). The cathode may be prepared by evaporation or sputtering, and metal materials such as aluminum and silver or ITO may be used; preparing an electron transport layer 33 on the substrate 10, and the electron transport layer may be prepared by spin coating, evaporation, or sputtering. The electron transport layer may use an organic material or an inorganic material. The organic material may be BPhen, etc., and the inorganic material may be Sol-gel ZnO, ZnO nanoparticles, ZnMgO nanoparticles, etc.;

[0128] Preparing a light-emitting layer on the electron transport layer 33; coating the quantum dot material in the present invention on the electron transport layer 33, and exposing and developing the quantum dot material in the pixel region by using a mask plate, which may specifically include:

[0129] The quantum dot material having a first quantum dot body may be spin-coated in a first pixel region, and the first pixel region is exposed and developed to prepare a first quantum dot body material layer 24 having a first quantum dot body; the first quantum dot body may emit red light;

[0130] A quantum dot material with a second quantum dot body can be spin-coated on the second pixel region, and the second pixel region can be exposed and developed to prepare a second quantum dot body material layer 25 with the second quantum dot body; the second quantum dot body can emit green light;

[0131] A quantum dot material with a third quantum dot body can be spin-coated on the third pixel region, and the third pixel region can be exposed and developed to prepare a third quantum dot body material layer 26 with the third quantum dot body; the third quantum dot body can emit blue light; during the development process, organic solvents such as toluene can be used to remove the unexposed quantum dot material.

[0132] A hole transport layer (HTL), a hole injection layer (HIL), and a top electrode can be sequentially prepared. The top electrode can be an anode, and finally the device can be encapsulated with an ultraviolet curable glue. The HTL layer can be prepared by spin coating, evaporation, or sputtering. The HTL layer can use organic materials such as TFB, NPB, TCTA, TPD, Poly-TPD, CBP, PPV, PVK, etc.; the HTL layer can use inorganic materials such as NiO, WO3, CuSCN, etc.; the HIL layer can be prepared by spin coating or evaporation, such as evaporating HAT-CN, MoO3, LiF, NaF, MgF2, etc.

[0133] The present invention will be further described below through some specific embodiments.

[0134] Example 1

[0135] Preparation of quantum dot ligands:

[0136] Dichloromethane solvent is added to the reactor, and then the acyl chloride compound with structural formula I and the primary amine compound with structural formula II are added to the reactor, and the reaction is carried out under anhydrous and anaerobic conditions to prepare quantum dot ligands;

[0137] The specific reaction of structural formula I and structural formula II can be as shown in formula (s3):

[0138]

[0139] Among them, the reaction temperature is 0 °C, the reaction time is 4 h, and the molar ratio of the acyl chloride compound to the primary amine compound is 1.2;

[0140] Preparation of quantum dot materials:

[0141] The CdSe / ZnS quantum dot solution with oleic acid on the surface can be mixed with the quantum dot ligands prepared above to replace the ligands to prepare quantum dot materials;

[0142] Preparation of light-emitting devices:

[0143] A cathode is prepared on a glass substrate, and then an electron transport layer (ETL) is prepared. The ETL layer can be ZnO nanoparticles;

[0144] The above-prepared quantum dot material is spin-coated on the pixel area on the ETL layer, and the quantum dot material in the pixel area is exposed and developed using a mask;

[0145] A hole transport layer (HTL), a hole injection layer (HIL), and an anode are sequentially prepared. The HTL layer can use NiO, and the HIL layer can use MoO3. Then, the device is encapsulated with ultraviolet curable glue to prepare a light-emitting device.

[0146] Example 2

[0147] The difference between Example 2 and Example 1 is that:

[0148] In Example 2, the reaction temperature is 30 °C, the reaction time is 1 h, and the molar ratio of the acyl chloride compound to the primary amine compound is 1.

[0149] Example 3

[0150] The difference between Example 3 and Example 1 is that:

[0151] In Example 3, the reaction temperature is 15 °C, the reaction time is 2.5 h, and the molar ratio of the acyl chloride compound to the primary amine compound is 1.1.

[0152] Example 4

[0153] Prepare quantum dot ligands:

[0154] Add an ethanol solvent to the reactor, and then add a 2,4-dinitrofluorobenzene compound with the structural formula Ⅲ and a primary amine compound with an amide group with the structural formula Ⅳ to the reactor to react under light-shielded conditions to prepare quantum dot ligands, specifically as shown in formula (s6):

[0155]

[0156] Among them, the reaction temperature is 70 °C, the reaction time is 3 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound with an amide group is 1.3;

[0157] Prepare quantum dot materials:

[0158] The CdSe / ZnS quantum dot solution with oleic acid on the surface can be mixed with the above-prepared quantum dot ligands for ligand exchange to prepare quantum dot materials;

[0159] Prepare a light-emitting device:

[0160] A cathode is prepared on a glass substrate, and then an electron transport layer (ETL) is prepared. The ETL layer is ZnO nanoparticles;

[0161] The above-prepared quantum dot material is spin-coated on the pixel area on the ETL layer, and the quantum dot material in the pixel area is exposed and developed using a mask;

[0162] A hole transport layer (HTL), a hole injection layer (HIL), and an anode are sequentially prepared. The HTL layer can use NiO, and the HIL layer can use MoO3. Then, the device is encapsulated with an ultraviolet curable adhesive to prepare a light-emitting device.

[0163] Example 5

[0164] The difference between Example 5 and Example 4 is that:

[0165] In Example 5, the reaction temperature is 95 °C, the reaction time is 1 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound containing an amide group is 1.

[0166] Example 6

[0167] The difference between Example 6 and Example 4 is that:

[0168] In Example 6, the reaction temperature is 85 °C, the reaction time is 2 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound containing an amide group is 1.2.

[0169] The light-emitting devices in the above examples are subjected to performance tests. The light-emitting devices in Examples 1 - 6 have stable light-emitting performance, good light-emitting effects, high light-emitting efficiency, long service life, and can meet the requirements of light-emitting display.

[0170] The display panel of the embodiment of the present invention includes:

[0171] The light-emitting device described in the above examples. The display panel with the light-emitting device described in the above examples has a good display effect and can meet the display requirements.

[0172] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims, and all belong to the protection scope of the present invention.

Claims

1. A quantum dot material, characterized in that, Comprising: A quantum dot body and a quantum dot ligand, wherein the coordination group of the quantum dot body and the quantum dot ligand is connected by a chemical bond; the quantum dot ligand includes a photosensitive molecule, and the photosensitive molecule has a benzene ring, a coordination group and an amide group, and the coordination group is connected to the benzene ring through the amide group.

2. The quantum dot material according to claim 1, wherein The structural formula of the photosensitive molecule is: Wherein, R1, R4-R7 are selected from H, alkyl, halogen atom, -NO2, -CN, -COOH, -CHO, at least one of R1 and R4 is -NO2, R3 is selected from methylene, O, -NH-, S, and R2 is a coordination group.

3. The quantum dot material according to claim 2, wherein The structural formula of the photosensitive molecule is:

4. The quantum dot material according to claim 2, characterized in that, The structural formula of the photosensitive molecule includes at least one of structural formula (1) and structural formula (2):

5. The quantum dot material according to claim 1, characterized in that, The coordination group includes: At least one of carboxyl group, amino group, mercapto group, hydroxyl group, and silane coupling group.

6. A preparation method of a quantum dot material, characterized in that, Comprising: Adding an organic solvent into a reactor, and then adding an acyl chloride compound with structural formula I and a primary amine compound with structural formula II into the reactor to react under anhydrous and anaerobic conditions to prepare a quantum dot ligand; Wherein, the reaction temperature is 0-30 °C, the reaction time is 1-4 h, and the molar ratio of the acyl chloride compound to the primary amine compound is 1-1.2; Structural formula I is: A1 and A2 are selected from H, alkyl, -NO2, and at least one of A1 and A2 is selected as -NO2, and n is a positive integer; Structural formula II is: m is a positive integer, and X1 is a coordination group; Mixing a quantum dot solution with a quantum dot ligand and replacing the ligand to prepare a quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

7. A preparation method of a quantum dot material, characterized in that, Comprising: Adding an organic solvent into a reactor, and then adding a 2,4-dinitrofluorobenzene compound with structural formula III and a primary amine compound containing an amide group with structural formula IV into the reactor to react under light-shielded conditions to prepare a quantum dot ligand; Wherein, the reaction temperature is 70-95 °C, the reaction time is 1-3 h, and the molar ratio of the 2,4-dinitrofluorobenzene compound to the primary amine compound containing an amide group is 1-1.3; Structural formula III is: B1-B5 are selected from H, alkyl, phenyl, -NO2, and at least one of B1 and B5 is selected as -NO2; Structural formula IV is: C1 is selected from H, alkyl, phenyl, and C2 is a coordination group; Mixing a quantum dot solution with a quantum dot ligand and replacing the ligand to prepare a quantum dot material, and the coordination group in the quantum dot ligand is connected to the quantum dot body through a chemical bond.

8. A light-emitting device, characterized in that, Comprising: A substrate, the pixel region of the substrate has a light-emitting layer, the light-emitting layer includes a quantum dot body and a ligand structure, the ligand structure includes a coordination group and an amino group, and the coordination group is connected to the quantum dot body through a chemical bond.

9. The light-emitting device according to claim 8, wherein, The quantum dot body includes a first quantum dot body and a second quantum dot body. The first quantum dot body is used to emit light with a first wavelength, and the second quantum dot body is used to emit light with a second wavelength. The first wavelength is different from the second wavelength. The pixel region includes a first pixel region and a second pixel region. The first quantum dot body is disposed in the first pixel region, and the second quantum dot body is disposed in the second pixel region.

10. The light-emitting device according to claim 9, characterized in that, The quantum dot body further includes a third quantum dot body. The pixel region further includes a third pixel region. The third quantum dot body is used to emit light with a third wavelength. The first wavelength, the second wavelength, and the third wavelength are different from each other. The third quantum dot body is disposed in the third pixel region.

11. A method for preparing a light-emitting device, characterized in that, Comprising: Coating the quantum dot material according to any one of claims 1-5 on the pixel region of the substrate, exposing the quantum dot material in the pixel region and developing to form a light-emitting layer; Wherein, the light-emitting layer includes a quantum dot body and a ligand structure. The ligand structure includes a coordination group and an amino group. The coordination group is connected to the quantum dot body through a chemical bond.

12. A display panel, characterized in that, Comprising: The light-emitting device according to any one of claims 8-10.

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