Nano material and preparation method thereof, photoelectric device and display device

Abstract

The invention discloses a nano material and a preparation method thereof, a photoelectric device and a display device, and relates to the technical field of display. The nano material comprises quantum dots and a complex, and the complex is formed by complexing procyanidine and metal ions. The nano material provided by the invention has relatively high stability.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a nanomaterial and its preparation method, optoelectronic devices, and display apparatus. Background Technology

[0002] Quantum dots are nanoscale semiconductors. By applying a specific electric field or light pressure to these nanoscale semiconductor materials, they emit light of a specific frequency. The frequency of the emitted light changes with the size of the semiconductor, thus the color of the emitted light can be controlled by adjusting the size of the nanoscale semiconductor. Due to the quantum confinement effect and quantum size effect, quantum dots possess excellent properties such as broad excitation spectra, narrow half-width at half-maximum (HWHM), tunable wavelength, and solution processing capabilities. Quantum dots are widely used in optoelectronics, biomedicine, and other fields.

[0003] Among related technologies, quantum dots have poor stability and need further improvement. Summary of the Invention

[0004] In view of this, this application provides a nanomaterial and its preparation method, an optoelectronic device, and a display device.

[0005] The embodiments of this application are implemented as follows: a nanomaterial comprising quantum dots and a complex, wherein the complex is formed by the complexation of proanthocyanidins and metal ions.

[0006] Accordingly, this application also provides a method for preparing nanomaterials, comprising the following steps:

[0007] A quantum dot dispersion and a complex are provided, wherein the quantum dot dispersion comprises quantum dots and a first solvent, and the complex is formed by complexing proanthocyanidins and metal ions;

[0008] The complex and the quantum dot dispersion are mixed to obtain nanomaterials.

[0009] Accordingly, this application also provides an optoelectronic device, including an anode, a light-emitting layer and a cathode stacked sequentially, wherein the material of the light-emitting layer includes the above-mentioned nanomaterials, or nanomaterials prepared by the above-mentioned preparation method.

[0010] Accordingly, this application also provides a display device, which includes the above-mentioned optoelectronic device.

[0011] The nanomaterials provided in this application have high stability. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of the preparation method of nanomaterials provided in the embodiments of this application;

[0014] Figure 2 This is a schematic diagram of the structure of the optoelectronic device provided in the embodiments of this application;

[0015] Figure 3 This is a schematic diagram of the structure of another optoelectronic device provided in the embodiments of this application.

[0016] Figure label:

[0017] Optoelectronic device 100; anode 10; light-emitting layer 20; cathode 30; hole functional layer 40; electron functional layer 50. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0019] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0020] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0021] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0023] In optoelectronic devices, electron mobility is typically high while hole mobility is low. This carrier imbalance leads to excessive electron injection, resulting in electron accumulation in the quantum dot luminescent layer. This increases the probability of non-luminescent recombination of electrons and holes, such as through Auger recombination, which results in energy loss and affects the luminous efficiency of the optoelectronic device.

[0024] During operation, optoelectronic devices generate a large number of free radicals and heat. The accumulation of free radicals can affect the normal operation and stability of optoelectronic devices. Without a good way to dissipate heat, the temperature in some areas where heat is concentrated can become too high, which can lead to quantum dot failure or even the appearance of dead dots, seriously affecting the stability of optoelectronic devices.

[0025] The technical solution of this application is as follows:

[0026] In a first aspect, embodiments of this application provide a nanomaterial comprising quantum dots and a complex, wherein the complex is formed by complexing proanthocyanidins and metal ions.

[0027] It should be noted that proanthocyanidins are a general term for a large class of polyphenolic compounds widely found in plants. Their common characteristic is that they can all produce anthocyanins when heated in an acidic medium, hence the name proanthocyanidins. Structurally, proanthocyanidins are a mixture of polyphenols composed of varying numbers of catechins and epicatechins, and they possess multiple phenolic hydroxyl groups.

[0028] It should also be noted that proanthocyanidins are organic compounds whose spatial structure and electron distribution change with interaction with the external environment. Proanthocyanidins have many functional groups, such as phenolic hydroxyl groups, which are exposed to the environment and can easily capture other active free radicals in the form of hydrogen donors. This leads to the generation of negative charges, making proanthocyanidins negatively charged. In the process of preparing nanomaterials in solution, the large number of phenolic hydroxyl groups in proanthocyanidins can release hydrogen ions through dissociation, which can make proanthocyanidins negatively charged. Since proanthocyanidins contain a large number of phenolic hydroxyl groups, only some of the phenolic hydroxyl groups will complex with metal ions. Therefore, the complexes formed by proanthocyanidins and metal ions still carry negative charges.

[0029] The nanomaterials provided in this application utilize surface modification of quantum dots using complexes. These complexes carry a negative charge, resulting in negatively charged nanomaterials. In this negatively charged state, electron injection is hindered while hole injection is enhanced, effectively increasing hole injection efficiency and decreasing electron injection efficiency, thus achieving a greater balance between hole and electron injection. The complexes contain phenolic hydroxyl groups, which can capture free radicals in free radical reaction chains, preventing these chains from proceeding and improving the stability of the nanomaterials. The proanthocyanidins forming the complexes also possess good anti-photobleaching properties, effectively absorbing and neutralizing free radicals generated by light, thereby reducing damage to the quantum dots and improving their stability. The metal ions in the complexes effectively improve the conductivity and heat dissipation capacity of the nanomaterials. The metal ions can evenly distribute heat energy, preventing localized overheating and further enhancing the stability of the nanomaterials.

[0030] Specifically, after the complex captures free radicals in the free radical reaction chain, the phenolic hydroxyl group in the complex can act as a hydrogen or electron donor to react with the free radical, generating a stable semiquinone free radical through a hydrogen extraction reaction, thereby preventing the free radical reaction chain from continuing.

[0031] In some embodiments, the complex carries a negative charge.

[0032] In some embodiments, the nanomaterial carries a negative charge. It is understood that the negative charge of the complex causes the nanomaterial to carry a negative charge.

[0033] In some embodiments, the mass ratio of the proanthocyanidins to the metal ions is (3–10):1, meaning the complex is formed by the complexation of the proanthocyanidins and the metal ions at a mass ratio of (3–10):1. For example, this ratio can be 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or any range between two ratios. Within this mass ratio range, the metal ions can effectively complex with the proanthocyanidins, improving the stability, conductivity, and heat dissipation of the complex.

[0034] In some embodiments, the complex is attached to the quantum dot in the nanomaterial. Specifically, the complex contains a plurality of phenolic hydroxyl groups, and the complex is attached to the quantum dot through at least some of the phenolic hydroxyl groups.

[0035] In some embodiments, the degree of polymerization of the proanthocyanidins is 2 to 10, for example, 2, 3, 4, 5, 6, 7, 8, or 9. Further, the degree of polymerization of the proanthocyanidins is 2 to 5; in other words, the proanthocyanidins are oligomeric proanthocyanidins. Oligomeric proanthocyanidins have a lower degree of polymerization, occupy less space, and have a stronger ability to absorb free radicals, which can effectively improve the stability of the composite material.

[0036] In some embodiments, the proanthocyanidins contain phenolic hydroxyl groups, and the mass fraction of the phenolic hydroxyl groups in the proanthocyanidins is 25% to 35%, for example, it can be 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or any range between two values. Within the mass fraction range of the phenolic hydroxyl groups, the phenolic hydroxyl groups in the proanthocyanidins can effectively complex with metal ions and coordinate with quantum dots.

[0037] In some embodiments, the proanthocyanidins contain multiple phenolic hydroxyl groups, and the complex is formed by the proanthocyanidins through complexation of at least some of the phenolic hydroxyl groups with the metal ions. It is understood that the proanthocyanidins contain multiple phenolic hydroxyl groups, and during the complexation process with the metal ions, at least some of the phenolic hydroxyl groups in the proanthocyanidins complex with the metal ions to form the complex. It is also understood that the proanthocyanidins contain a large number of phenolic hydroxyl groups; some phenolic hydroxyl groups complex with the metal ions, while some phenolic hydroxyl groups remain uncomplexed. The phenolic hydroxyl groups complexed with the metal ions are the phenolic hydroxyl groups of the complex, and the complex can be coordinated with quantum dots through these uncomplexed phenolic hydroxyl groups.

[0038] In some embodiments, the mass ratio of the quantum dots to the complex in the nanomaterial is (5–15):1, for example, it can be 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or any range between two ratios. Within the range of the mass ratio, the complex can effectively regulate the charge state of the nanomaterial, promote hole injection while inhibiting electron injection, promote the balance between holes and electrons, and improve the stability of the nanomaterial.

[0039] In some embodiments, the metal ions include silver ions. Silver has a conductivity of 6.3 × 10⁻⁶ at 20°C. 7With a thermal conductivity of 429 W / m·K, which is much higher than that of other metals, silver ions can effectively improve the electrical conductivity and heat dissipation of nanomaterials. Furthermore, silver ions have empty d orbitals, which make them easy to complex with proanthocyanidins to form complexes.

[0040] In some embodiments, the average particle size of the quantum dots is 5 nm to 15 nm, for example, it can be 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, or any range between two values. It should be noted that in this application, the particle size of the quantum dots is measured using a transmission electron microscope (TEM).

[0041] In some embodiments, the quantum dots may be selected from, but are not limited to, one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0042] The materials for the single-structure quantum dots, the core material of the core-shell quantum dots, and the shell material of the core-shell quantum dots can be selected from, but are not limited to, one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The shell of the core-shell quantum dots can be one or more layers. The group II-VI compounds may be selected from, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may be selected from, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The group III-V compounds may be selected from, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The group I-III-VI compounds may be selected from, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0043] As an example, the core-shell structured quantum dots can be selected from, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS. In the above descriptions of CdSe / ZnS, etc., the " / " indicates that the material after the " / " (as the shell) covers the material before the " / " (as the core).

[0044] The perovskite semiconductor material can be selected from, but is not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMZ3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of the following, where Z is a halide anion selected from Cl. - ,Br - I - One or more of the following. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMZ3, where B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of the following, where Z is a halide anion selected from Cl. - ,Br - I -One or more of them.

[0045] It should be noted that conventional ligands known in the art can also be connected to the quantum dots.

[0046] Specifically, in some embodiments, the quantum dot is also connected to a ligand.

[0047] Furthermore, the mass ratio of the quantum dot to the ligand is (10–20):1, for example, it can be 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, or any range between two ratios. Within the range of the stated mass ratio, the ligand can effectively improve the solubility, dispersibility, stability, and biocompatibility of the quantum dot.

[0048] In some embodiments, the ligand includes one or more of the following: aliphatic amine ligands having 1 to 24 carbon atoms, fatty acid ligands having 1 to 24 carbon atoms, carboxyl ligands, phosphate ligands, halide ion ligands, thiol ligands having 1 to 24 carbon atoms, trialiphatic phosphine having 9 to 30 carbon atoms, triarylphosphine having 18 to 30 carbon atoms, trialiphatic phosphine oxide having 9 to 30 carbon atoms, and triarylphosphine oxide having 18 to 30 carbon atoms.

[0049] The aliphatic amine ligands having 1 to 24 carbon atoms include one or more of oleylamine, n-decylamine, octylamine, dioctylamine, trioctylamine, dodecylamine, myristicamine, palmitamine, and stearylamine.

[0050] The fatty acid ligands having 1 to 24 carbon atoms include one or more of oleic acid, decanoic acid, caprylic acid, dicaprylic acid, tricaprylic acid, dodecanoic acid, myristic acid, palmitic acid, stearic acid, thioglycolic acid, and thiopropionic acid.

[0051] The carboxylate ligand is selected from one or more of magnesium carboxylate ligands, calcium carboxylate ligands, aluminum carboxylate ligands, zirconium carboxylate ligands, lithium carboxylate ligands, sodium carboxylate ligands, and barium carboxylate ligands. The carboxyl group in the carboxylate ligand is a fatty acid ion with 1 to 20 carbon atoms.

[0052] The phosphate ligand is selected from one or more of magnesium phosphate ligand, calcium phosphate ligand, aluminum phosphate ligand, zirconium phosphate ligand, lithium phosphate ligand, sodium phosphate ligand, and barium phosphate ligand.

[0053] The halide ion ligand is selected from one or more of fluoride ions, chloride ions, bromide ions, and iodide ions.

[0054] The thiol ligand having 1 to 24 carbon atoms is selected from one or more of 1,2-ethanedithiol, propanethiol, butanethiol, octylthiol, dodecanethiol, octadecylthiol, benzylthiol, 1,2-benzenethiol, 1,3-benzenethiol, and 1,4-benzenethiol.

[0055] The trialiphatic phosphine having 9 to 30 carbon atoms is selected from one or more of tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, triheptylphosphine, trioctylphosphine, trinonylphosphine, and tridecylphosphine.

[0056] The triarylphosphine having 18 to 30 carbon atoms is selected from one or more of triphenylphosphine, tri(m-toluene)phosphine, tri(2-toluene)phosphine, and tri(p-methylphenyl)phosphine.

[0057] The trialiphatic phosphine oxide with 9 to 30 carbon atoms is selected from one or more of tripropylphosphine oxide, tributylphosphine oxide, tripentylphosphine oxide, trihexylphosphine oxide, triheptylphosphine oxide, trioctylphosphine oxide, trinonylphosphine oxide, and tridecylphosphine oxide.

[0058] The triarylphosphine oxide having 18 to 30 carbon atoms is selected from one or more of triphenylphosphine oxide, tri(m-toluene)phosphine oxide, tri(2-toluene)phosphine oxide, and tri(p-methylphenyl)phosphine oxide.

[0059] Secondly, please refer to Figure 1 This application also provides a method for preparing nanomaterials, comprising the following steps:

[0060] S11. A quantum dot dispersion and a complex are provided, wherein the quantum dot dispersion comprises quantum dots and a first solvent, and the complex is formed by complexing proanthocyanidins and metal ions;

[0061] S12. Mix the complex and the quantum dot dispersion to obtain nanomaterials.

[0062] It should be noted that quantum dots can be synthesized using conventional methods in the field, such as organic phase synthesis, aqueous phase synthesis, hydrothermal method, solvothermal method, microwave-assisted hydrothermal method, microemulsion method, physical vapor deposition, chemical vapor deposition, sol-gel method, precipitation method, epitaxial growth method, electric field confinement method, etc.

[0063] In the process of synthesizing quantum dots, conventional ligands known in the art can be introduced onto the surface of the quantum dots. The materials of the ligands are described above and will not be repeated here.

[0064] In some embodiments, the mass concentration of the quantum dots in the quantum dot dispersion is between 10 mg / mL and 30 mg / mL, for example, it can be 11 mg / mL, 12 mg / mL, 13 mg / mL, 14 mg / mL, 15 mg / mL, 16 mg / mL, 17 mg / mL, 18 mg / mL, 19 mg / mL, 20 mg / mL, 21 mg / mL, 22 mg / mL, 23 mg / mL, 24 mg / mL, 25 mg / mL, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL, or any range between two values. Within this mass concentration range, the dissolution and dispersion of the quantum dots are beneficial.

[0065] In some embodiments, the first solvent includes a nonpolar solvent, which includes one or more of n-hexane, n-heptane, n-octane, isooctane, cyclohexane, benzene, toluene, xylene, ethylbenzene, carbon tetrachloride, chloroform, and dichloromethane.

[0066] In some embodiments, the mass ratio of the quantum dot to the complex is (5–15):1, for example, it can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or any range between two ratios. Within the range of the mass ratio, the proanthocyanidins can be effectively coordinated with the quantum dots.

[0067] In some embodiments, the method for preparing the complex includes:

[0068] S121. Provide a proanthocyanidin dispersion and a metal salt, wherein the proanthocyanidin dispersion includes proanthocyanidins and a second solvent;

[0069] S122. Mix the metal salt and the proanthocyanidin dispersion to obtain a complex.

[0070] In some embodiments, the proanthocyanidin dispersion contains proanthocyanidin at a concentration of 10 mg / mL to 30 mg / mL, for example, 11 mg / mL, 12 mg / mL, 13 mg / mL, 14 mg / mL, 15 mg / mL, 16 mg / mL, 17 mg / mL, 18 mg / mL, 19 mg / mL, 20 mg / mL, 21 mg / mL, 22 mg / mL, 23 mg / mL, 24 mg / mL, 25 mg / mL, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL, or any range between two values. Within this concentration range, the dissolution and dispersion of the proanthocyanidins are favorable.

[0071] In some embodiments, the second solvent includes a polar solvent, which includes one or more of trimethoxybutanol, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, tetrahydrofuran, N,N-dimethylformamide, pyrrole, and butyric acid.

[0072] In some embodiments, the metal salt includes a silver salt.

[0073] Furthermore, the silver salt includes one or more of silver chloride, silver nitrate, silver bromide, silver iodide, and silver cyanide.

[0074] In some embodiments, the mass ratio of the proanthocyanidin to the metal salt is (5–15):1, for example, it can be 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or any range between two ratios. Within the range of the mass ratio, it is beneficial for the metal ions in the metal salt and the proanthocyanidin to connect through complexation.

[0075] In some embodiments, the mixing temperature of the metal salt and the proanthocyanidin dispersion is 60°C to 80°C, for example, it can be 62°C, 65°C, 68°C, 70°C, 72°C, 75°C, 78°C, or any range between two values. The mixing time of the metal salt and the proanthocyanidin dispersion is 1 hour to 3 hours, for example, it can be 1.2 hours, 1.5 hours, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, or any range between two values. Under these conditions, it is beneficial for the metal ions in the metal salt and the proanthocyanidins to fully complex and form a complex.

[0076] It is understood that when the proanthocyanidins are in solution, some of the phenolic hydroxyl groups in the proanthocyanidins can release hydrogen ions through dissociation, making the proanthocyanidins carry a negative charge.

[0077] In some embodiments, mixing the complex and the quantum dot dispersion includes: providing a complex dispersion comprising the complex and a third solvent, and mixing the complex dispersion and the quantum dot dispersion.

[0078] In some embodiments, the mass concentration of the complex in the dispersion is 5 mg / mL to 20 mg / mL, for example, it can be 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL, 11 mg / mL, 12 mg / mL, 13 mg / mL, 14 mg / mL, 15 mg / mL, 16 mg / mL, 17 mg / mL, 18 mg / mL, 19 mg / mL, or any range between two values. Within this mass concentration range, the dissolution and dispersion of the complex are favorable.

[0079] In some embodiments, the third solvent comprises a polar solvent, which includes one or more of trimethoxybutanol, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, tetrahydrofuran, N,N-dimethylformamide, pyrrole, and butyric acid.

[0080] In some embodiments, the mixing temperature of the complex dispersion and the quantum dot dispersion is 80°C to 90°C, for example, it can be 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, or any range between two values. The mixing time of the complex dispersion and the quantum dot dispersion is 30 min to 60 min, for example, it can be 35 min, 40 min, 45 min, 50 min, 55 min, or any range between two values. Under these conditions, it is beneficial for the complex to coordinate and connect to the quantum dot surface, resulting in nanomaterials.

[0081] It should be noted that the complex can directly coordinate with the exposed metal ions on the surface of the quantum dot, or it can replace some of the ligands on the quantum dot and coordinate with the quantum dot.

[0082] This application also provides an ink comprising the above-mentioned nanomaterial and a fourth solvent.

[0083] In some embodiments, the mass concentration of the nanomaterial in the ink is between 10 mg / mL and 30 mg / mL, for example, it can be 11 mg / mL, 12 mg / mL, 13 mg / mL, 14 mg / mL, 15 mg / mL, 16 mg / mL, 17 mg / mL, 18 mg / mL, 19 mg / mL, 20 mg / mL, 21 mg / mL, 22 mg / mL, 23 mg / mL, 24 mg / mL, 25 mg / mL, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL, or any range between two values. Within this mass concentration range, uniform dissolution and dispersion of the nanomaterial is beneficial.

[0084] In some embodiments, the fourth solvent includes a nonpolar solvent, which includes one or more of the following: n-hexane, n-heptane, n-octane, isooctane, cyclohexane, benzene, toluene, xylene, ethylbenzene, carbon tetrachloride, chloroform, and dichloromethane.

[0085] This application also provides a thin film, the material of which includes the above-mentioned nanomaterials.

[0086] The thin film can be prepared using conventional techniques in the art, such as chemical or physical methods. Chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include physical deposition and solution methods. Physical deposition methods include thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating, etc.

[0087] The film can be prepared using the above-mentioned ink via a solution method.

[0088] Thirdly, please refer to Figure 2 This application also provides an optoelectronic device 100, which includes an anode 10, a light-emitting layer 20 and a cathode 30 stacked sequentially. The material of the light-emitting layer 20 includes the above-mentioned nanomaterials or nanomaterials prepared by the above-mentioned preparation method.

[0089] In the optoelectronic device 100 provided in this application, the complex is bonded to the surface of the quantum dots via phenolic hydroxyl groups and exists on the surface of the quantum dots in the form of ligands. This makes the nanomaterial as a whole negatively charged, thereby making the light-emitting layer 20 negatively charged. Electron injection is hindered, while hole injection is enhanced, thus improving the hole carrier injection efficiency and reducing the electron carrier injection efficiency. This balances the carrier injection in the device and improves the luminous efficiency of the optoelectronic device 100. The metal ions in the complex can improve the conductivity of the light-emitting layer 20 and promote hole injection. The transmission of light increases the probability of radiative recombination, enhancing the ability of the optoelectronic device 100 to convert electricity into light. Metal ions can also improve the heat dissipation capacity of the light-emitting layer 20. By connecting the metal ions with the quantum dots through proanthocyanidins, the thermal conductivity of the metal ions can be fully utilized to uniformly transfer heat to all areas of the light-emitting layer 20, preventing local overheating and improving the heat dissipation capacity of the light-emitting layer 20. Furthermore, the optoelectronic device 100 can still have good heat resistance after long-term operation, ensuring long-term stable operation of the device and extending the service life of the optoelectronic device 100.

[0090] After prolonged operation, the optoelectronic device 100 generates a large number of free radicals, such as hydroxyl radicals and superoxide anion radicals. The phenolic hydroxyl groups in the complex can capture these free radicals, preventing the free radical reaction chain from continuing. Simultaneously, the phenolic hydroxyl groups can act as hydrogen or electron donors, reacting with free radicals to generate stable semiquinone radicals through hydrogen extraction reactions. This interrupts the free radical chain reaction, achieving the purpose of free radical scavenging and ensuring the long-term stable operation of the optoelectronic device 100. The proanthocyanidins in the complex also possess good anti-photobleaching ability, effectively absorbing and neutralizing free radicals generated by light, thereby reducing damage to the nanomaterial's function, maintaining its optical properties and stability, and ultimately improving the stability and performance of the optoelectronic device 100.

[0091] In some embodiments, the thickness of the light-emitting layer 20 is 10nm to 40nm, for example, it can be 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, or any range between two values. It should be noted that in this application, the thickness of the film layer is measured using a profilometer.

[0092] In some embodiments, the optoelectronic device 100 includes a light-emitting diode.

[0093] In some embodiments, please refer to Figure 3 The optoelectronic device 100 further includes one or more of a hole functional layer 40 and an electronic functional layer 50. The hole functional layer 40 is disposed between the anode 10 and the light-emitting layer 20, and the electronic functional layer 50 is disposed between the light-emitting layer 20 and the cathode 30.

[0094] Furthermore, the hole functional layer 40 includes one or more of a hole injection layer and a hole transport layer.

[0095] The electronic functional layer 50 includes one or more of an electron injection layer and an electron transport layer.

[0096] In some embodiments, the anode 10 and the cathode 30 each independently include one or more of a metal electrode, a carbon electrode, a metal oxide electrode, and a composite electrode; the material of the metal electrode includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the material of the carbon electrode includes one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO; the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. In this context, " / " indicates a stacked structure. For example, AZO / Ag / AZO represents a composite electrode consisting of sequentially stacked AZO, Ag, and AZO layers.

[0097] In some embodiments, the material of the electronic functional layer 50 includes an N-type semiconductor material. The N-type semiconductor material includes one or more of the following: first doped metal oxide particles, first undoped metal oxide particles, group IIB-VIA semiconductor materials, group IIIA-VA semiconductor materials, and group IB-IIIA-VIA semiconductor materials. The material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the first doped metal oxide particles includes Al, Mg, Li, Mn, Y, ... The semiconductor materials are selected from one or more of La, Cu, Ni, Zr, Ce, In, and Ga; the IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, and CdS; the IIIA-VA group semiconductor materials include one or more of InP and GaP; and the IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS. The doping amount of the doping element in the first doped metal oxide particle is 0.1wt% to 15wt%, for example, it can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, or any range between two values.

[0098] In some embodiments, the material of the hole functional layer 40 includes an organic p-type semiconductor material or an inorganic p-type semiconductor material, wherein the organic p-type semiconductor material includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'- bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4, 4'-(N-(4-sec-butylphenyl)diphenylamine)], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-)phenylenevinylene, poly(phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene], copper phthalocyanine, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1, 1'-Biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthyl-1-yl)-N,N'-diphenylbenzidine, spiron NPB, nanocrystalline diamond, microcrystalline cellulose and tetracyanoquinone dimethane, doped graphene, undoped graphene;The inorganic P-type semiconductor material comprises one or more of the following: second-doped metal oxide particles, second-undoped metal oxide particles, metal sulfides, metal selenides, and metal nitrides. The metal oxides in the second-doped metal oxide particles and the second-undoped metal oxide particles each independently comprise one or more of MoO3, WO3, NiO, CrO3, CuO, and V2O5. The doping element in the second-doped metal oxide particles comprises one or more of Mo, W, Ni, Cr, Cu, and V. The metal selenide includes one or more of CuS, MoS3, and WS3; the metal selenide includes one or more of MoSe3 and WSe3; and the metal nitride includes p-type gallium nitride. The doping amount of the dopant element in the second doped metal oxide particle is 0.1 wt% to 15 wt%, for example, it can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or any range between two values.

[0099] Fourthly, embodiments of this application also provide a display device, which includes the aforementioned optoelectronic device 100.

[0100] The display device can be any electronic product with display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0101] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0102] Nanomaterials Example 1

[0103] This embodiment provides a nanomaterial comprising CdSe / ZnS quantum dots and a complex attached to the surface of the quantum dots. The complex is formed by the complexation of proanthocyanidins and metal ions. The mass ratio of CdSe / ZnS quantum dots to the complex is 10:1. The preparation method includes:

[0104] A 20 mg / mL acetone dispersion of proanthocyanidins and a 10 mg / mL silver chloride dispersion were provided and mixed, wherein the mass ratio of proanthocyanidins to silver chloride in the dispersion was 10:1. The mixture was reacted at 70 °C for 2 h. After the reaction was completed, the product was centrifuged to obtain the complex.

[0105] The complex was redispersed in acetone to prepare a 10 mg / mL complex dispersion. A 20 mg / mL n-octane dispersion of CdSe / ZnS quantum dots was provided and mixed with the complex dispersion. The mass ratio of CdSe / ZnS quantum dots in the dispersion to the complex in the dispersion was 10:1. The mixture was reacted at 85 °C for 45 min to obtain nanomaterials.

[0106] Nanomaterials Example 2

[0107] This embodiment is basically the same as Example 1, except that the mass ratio of CdSe / ZnS quantum dots in the dispersion to the complex in the dispersion is 15:1, and the mass ratio of CdSe / ZnS quantum dots to the complex in the nanomaterial is 15:1.

[0108] Nanomaterials Example 3

[0109] This embodiment is basically the same as Example 1, except that the mass ratio of CdSe / ZnS quantum dots in the dispersion to the complex in the dispersion is 5:1, and the mass ratio of CdSe / ZnS quantum dots to the complex in the nanomaterial is 5:1.

[0110] Nanomaterials Example 4

[0111] This embodiment is basically the same as Embodiment 1, except that the reaction temperature of CdSe / ZnS quantum dots and complexes is 90℃ in this embodiment.

[0112] Nanomaterials Example 5

[0113] This embodiment is basically the same as Embodiment 1, except that the reaction temperature of CdSe / ZnS quantum dots and complexes is 80℃ in this embodiment.

[0114] Nanomaterials Example 6

[0115] This embodiment is basically the same as Embodiment 1, except that the reaction time of CdSe / ZnS quantum dots and complexes in this embodiment is 60 min.

[0116] Nanomaterials Example 7

[0117] This embodiment is basically the same as Embodiment 1, except that the reaction time of CdSe / ZnS quantum dots and complexes in this embodiment is 30 min.

[0118] Nanomaterials Example 8

[0119] This embodiment is basically the same as Embodiment 1, except that the mass ratio of proanthocyanidins in the dispersion to silver chloride in the dispersion is 15:1.

[0120] Nanomaterials Example 9

[0121] This embodiment is basically the same as Embodiment 1, except that the mass ratio of proanthocyanidins in the dispersion to silver chloride in the dispersion is 5:1.

[0122] Nanomaterials Example 10

[0123] This embodiment is basically the same as Embodiment 1, except that CdSe / ZnS quantum dots are replaced with CdZnS quantum dots in this embodiment.

[0124] Nanomaterials Comparative Example 1

[0125] This comparative example provides a nanomaterial, including CdSe / ZnS quantum dots.

[0126] Nanomaterials Comparative Example 2

[0127] This comparative example provides a nanomaterial, including CdZnS quantum dots.

[0128] Nanomaterials Comparative Example 3

[0129] This comparative example provides a nanomaterial, the preparation method of which includes:

[0130] 0.5g of CdSe / ZnS quantum dots were added to 30mL of ethanol and stirred. Then, 2.57g of octyl methoxycinnamate and 2mL of 30% sulfuric acid were added. The mixture was heated to 70℃ and stirred for 10min. After filtration through filter paper and washing three times with deionized water, the mixture was dried in an oven at 70℃ for 10min. Then, 0.2g of proanthocyanidins and 10mL of deionized water were added and stirred for 2h. Polysorbate was added and the mixture was stirred at 30℃ for 30min. Finally, the mixture was pulverized to obtain nanomaterials with CdSe / ZnS quantum dots as the core and proanthocyanidins as the shell.

[0131] The carrier mobility of the nanomaterials of Examples 1-10 and Comparative Examples 1-3 when applied to the semiconductor devices of optoelectronic devices was tested, and the results are shown in Table 1.

[0132] The carrier mobility test method is as follows: The current density-voltage curves of the optoelectronic devices (single carrier transport thin film devices HOD / EOD) of Examples 1-10 and Comparative Examples 1-3 are measured. The EOD structure is anode / quantum dot emitting layer / electron transport layer / cathode, with the quantum dot emitting layer made of the same nanomaterials as in Examples 1-10 and Comparative Examples 1-3, and the electron transport layer made of ZnO. The HOD structure is anode / hole transport layer / quantum dot emitting layer / cathode, with the quantum dot emitting layer made of the same nanomaterials as in Examples 1-10 and Comparative Examples 1-3, and the hole transport layer made of TFB. The materials of the anode, hole transport layer, electron transport layer, and cathode are the same as in Device Example 1 below. The space charge confinement current (SCLC) region in the current density-voltage curve is obtained, and then the current density is calculated according to the formula J = (9 / 8)ε. r ε0μ e V 2 / d 3 Calculate the electron / hole mobility, where J represents the current density in mA / cm². -2 ;ε r ε₀ represents the relative permittivity, and μ represents the vacuum permittivity. e Electron / hole mobility is expressed in cm. 2 V -1 s -1 V represents the driving voltage, with units of V; d represents the film thickness, with units of m.

[0133] Table 1

[0134]

[0135] From Table 1, we can obtain:

[0136] As can be seen from Examples 1-9 and Comparative Examples 1 and 3, after the quantum dots are modified with complexes, the electron injection in the semiconductor device when the nanomaterial is used as the light-emitting layer is reduced, and the hole injection and transport are improved, making the electron and hole more well-matched and balanced, which can promote the effective recombination and light emission of electrons and holes. Among them, in Comparative Example 3, the proanthocyanidin coating of quantum dots slightly reduced the electron injection and improved the hole injection, but the effect was not obvious. The electron mobility was higher than that of the examples, and the hole mobility was lower than that of the examples.

[0137] As can be seen from Example 10 and Comparative Example 2, the complex provided by this scheme is applicable to a variety of quantum dots, can promote the injection balance of electrons and holes, and improve the stability of quantum dots.

[0138] Device Example 1

[0139] This embodiment of the device provides an optoelectronic device, the fabrication method of which is as follows:

[0140] Provide ITO glass, use a cotton swab dipped in a small amount of soapy water to wipe the ITO surface to remove visible impurities, then use deionized water, acetone, ethanol, and isopropanol for ultrasonic cleaning for 15 minutes, then blow dry with nitrogen gas and irradiate with UV for 15 minutes to form an ITO anode.

[0141] 50 μL of PEDOT:PSS was pipetted onto the ITO anode and then spin-coated at 4000 rpm for 40 seconds. The mixture was then annealed at 150 °C for 15 min to form a hole injection layer.

[0142] 40 μL of TFB solution was pipetted onto the hole injection layer, and then spin-coated at 4000 rpm for 30 s. The mixture was then annealed at 140 °C for 15 min to form the hole transport layer.

[0143] The nanomaterials of Example 1 were dissolved in n-octane to prepare a 20 mg / mL solution. The solution was placed on the hole transport layer and spin-coated at 3000 rpm for 30 s. Then, it was annealed at 120 °C for 10 min to form a luminescent layer.

[0144] An ethanol solution of ZnO was spin-coated onto the luminescent layer at a speed of 4000 rpm for 30 seconds, and then heated at 130°C for 10 minutes to form an electron transport layer.

[0145] After placing it in the vacuum coating machine, the vacuum is evacuated to 4×10. -6 mbar, magnesium target material is deposited on the electron transport layer by vapor deposition, the magnesium target material is... A 20nm deposition rate was achieved; subsequently, the Ag target was activated, and the Ag target was deposited at... A cathode is formed by evaporating at a rate of 30 nm.

[0146] Packaging yields optoelectronic devices.

[0147] Device Examples 2-10

[0148] Device Examples 2-10 are basically the same as Device Example 1, except that the nanomaterials in Example 1 are replaced with the nanomaterials in Examples 2-10 to form a light-emitting layer and obtain optoelectronic devices.

[0149] Device Comparison Examples 1-3

[0150] The devices in Comparative Examples 1 to 3 are basically the same as those in Device Example 1, except that the nanomaterials in Example 1 are replaced with the nanomaterials in Comparative Examples 1 to 3 to form a light-emitting layer, thus obtaining optoelectronic devices.

[0151] The external quantum efficiency (EQE%) and lifetime (T95@1000nit) of the optoelectronic devices of Device Examples 1-10 and Device Comparative Examples 1-3 were tested, and the test results are shown in Table 2.

[0152] The external quantum efficiency (EQE) is measured as the ratio of electron-hole pairs injected into a quantum dot to emitted photons, expressed as a percentage (%). It is a crucial parameter for evaluating the quality of electroluminescent devices and can be obtained using an EQE optical testing instrument. The specific calculation formula is as follows:

[0153]

[0154] Where ηe is the optical output coupling efficiency, ηr is the ratio of recombination carriers to injected carriers, χ is the ratio of the number of excitons generating photons to the total number of excitons, and K R K is the radiation process rate. NR This represents the rate of a non-radiative process. Test conditions: conducted at room temperature with an air humidity of 30–60%.

[0155] The external quantum efficiency (EQE) was tested once upon completion of preparation (0h) and once after continuous operation for one day (24h). The stability was calculated by EQE@24h / EQE@0h*100%.

[0156] The test method for lifetime T95@1000nit is as follows: Under constant current or voltage drive, the time required for the brightness of the device to decrease to a certain percentage of its maximum brightness is defined as T95. This lifetime is the measured lifetime. To shorten the testing cycle, device lifetime testing is usually performed at high brightness by accelerating device aging, and the lifetime at high brightness is obtained by fitting the extended exponential decay brightness decay formula. For example, the lifetime at 1000nit is measured as T95@1000nit. The specific calculation formula is as follows:

[0157]

[0158] Among them, T95 L For longer lifespan at low brightness, T95 H For the measured lifetime under high brightness, L H To accelerate the device to its maximum brightness, L L The value is 1000 nits, and A is the acceleration factor. In this experiment, the lifetime of several groups of QLED devices under rated brightness was measured, and the value of A was found to be 1.7.

[0159] Table 2

[0160]

[0161]

[0162] From Table 2, we can obtain:

[0163] As can be seen from Device Examples 1-8 and Device Comparative Examples 1-3, using the nanomaterials provided in this application as the material of the light-emitting layer in the optoelectronic device can effectively improve the luminous efficiency of the optoelectronic device, and maintain a high luminous efficiency even after a period of operation. In particular, the metal ions in the complex improve the conductivity of the nanomaterials, giving the optoelectronic device high luminous efficiency and stability. Moreover, the metal ions promote heat dissipation of the optoelectronic device, avoiding local heat concentration that could damage the optoelectronic device, reducing the impact of light and heat on the optoelectronic device, improving the stability of the optoelectronic device, and extending the service life of the optoelectronic device. The luminous efficiency and service life performance of Device Comparative Example 3 are slightly better than those of Device Comparative Example 1, but still worse than those of Device Examples.

[0164] As can be seen from Device Example 10 and Device Comparative Example 2, the complex provided by this scheme has beneficial effects on a variety of quantum dots, which can improve the performance of quantum dots and thus improve the performance of optoelectronic devices.

[0165] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A nanomaterial, characterized in that, The nanomaterials include quantum dots and complexes, the complexes being formed by the complexation of proanthocyanidins and metal ions.

2. The nanomaterial as described in claim 1, characterized in that, The complex is negatively charged; and / or The mass ratio of the proanthocyanidins to the metal ions is (3-10):1; and / or The degree of polymerization of the proanthocyanidins is 2 to 10; optionally, the degree of polymerization of the proanthocyanidins is 2 to 5; and / or The proanthocyanidins contain phenolic hydroxyl groups, and the mass fraction of the phenolic hydroxyl groups in the proanthocyanidins is 25% to 35%; and / or The metal ions include silver ions; and / or The proanthocyanidin contains multiple phenolic hydroxyl groups, and the complex is formed by the proanthocyanidin through complexation of at least some of the phenolic hydroxyl groups and the metal ions.

3. The nanomaterial as described in claim 1, characterized in that, The nanomaterial carries a negative charge; and / or In the nanomaterial, the mass ratio of the quantum dots to the complex is (5-15):1; and / or In the nanomaterial, the complex is connected to the quantum dot; optionally, the complex contains a plurality of phenolic hydroxyl groups, and the complex is coordinated to the quantum dot through at least some of the phenolic hydroxyl groups.

4. The nanomaterial as described in claim 1, characterized in that, The average particle size of the quantum dots is 5 nm to 15 nm; and / or The quantum dots are selected from one or more of single-structure quantum dots, core-shell quantum dots, and perovskite quantum dots; the materials of the single-structure quantum dots, the core materials of the core-shell quantum dots, and the shell materials of the core-shell quantum dots are respectively selected from one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds; the shell of the core-shell quantum dots includes one or more layers; the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, C One or more of dSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are selected from SnS, SnSe, S The compounds are selected from one or more of the following: nTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V compounds are selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, and AlNAs. One or more of AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; wherein the group I-III-VI compounds are selected from one or more of CuInS2, CuInSe2, and AgInS2;The core-shell quantum dots are selected from one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS; the perovskite quantum dots are made of doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors; the inorganic perovskite semiconductor has the general structural formula AMX3, where A is Cs; + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of the following, where X is a halide anion selected from Cl... - ,Br - I - One or more of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of the following, where X is a halide anion selected from Cl... - ,Br - I - One or more of them.

5. The nanomaterial as described in claim 1, characterized in that, The quantum dots are also connected to ligands; among them... The mass ratio of the quantum dot to the ligand is (10-20):1; and / or The ligands include one or more of the following: aliphatic amine ligands with 1 to 24 carbon atoms, fatty acid ligands with 1 to 24 carbon atoms, carboxylate ligands, phosphate ligands, halide ion ligands, thiol ligands with 1 to 24 carbon atoms, trialiphatic phosphine with 9 to 30 carbon atoms, triarylphosphine with 18 to 30 carbon atoms, trialiphatic phosphine oxide with 9 to 30 carbon atoms, and triarylphosphine oxide with 18 to 30 carbon atoms. The aliphatic amine ligands with 1 to 24 carbon atoms include oleylamine, n-decylamine, octylamine, dioctylamine, trioctylamine, dodecylamine, myristamine, palmitamine, and styraxamine. One or more of the following amines; and / or the fatty acid ligand having 1 to 24 carbon atoms includes one or more of oleic acid, decanoic acid, octanoic acid, dioctanoic acid, trioctanoic acid, dodecanoic acid, myristic acid, palmitic acid, stearic acid, thioglycolic acid, and mercaptopropionic acid; and / or the carboxylate ligand is selected from one or more of magnesium carboxylate ligand, calcium carboxylate ligand, aluminum carboxylate ligand, zirconium carboxylate ligand, lithium carboxylate ligand, sodium carboxylate ligand, and barium carboxylate ligand; and / or the phosphate ligand is selected from one of magnesium phosphate ligand, calcium phosphate ligand, aluminum phosphate ligand, zirconium phosphate ligand, lithium phosphate ligand, sodium phosphate ligand, and barium phosphate ligand. Or multiple; and / or the halide ion ligand is selected from one or more of fluoride ions, chloride ions, bromide ions, and iodide ions; and / or the thiol ligand having 1 to 24 carbon atoms is selected from one or more of 1,2-ethanedithiol, propanethiol, butanethiol, octylthiol, dodecanethiol, octadecylthiol, benzenethiol, 1,2-benzenethiol, 1,3-benzenethiol, and 1,4-benzenethiol; and / or the trialiphatic phosphine having 9 to 30 carbon atoms is selected from one or more of tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, triheptylphosphine, trioctylphosphine, trinonylphosphine, and tridecylphosphine; and / or the... The triarylphosphine having 18 to 30 carbon atoms is selected from one or more of triphenylphosphine, tri(m-toluene), tri(2-toluene), and tri(p-methylphenyl)phosphine; and / or the trialilophosphine having 9 to 30 carbon atoms is selected from one or more of tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, triheptylphosphine, trioctylphosphine, trinonylphosphine, and tridecylphosphine; and / or the triarylphosphine having 18 to 30 carbon atoms is selected from one or more of triphenylphosphine, tri(m-toluene), tri(2-toluene), and tri(p-methylphenyl)phosphine.

6. A method for preparing nanomaterials, characterized in that, Includes the following steps: A quantum dot dispersion and a complex are provided, wherein the quantum dot dispersion comprises quantum dots and a first solvent, and the complex is formed by complexing proanthocyanidins and metal ions; The complex and the quantum dot dispersion are mixed to obtain nanomaterials.

7. The preparation method according to claim 6, characterized in that, The preparation method of the complex includes: providing a proanthocyanidin dispersion and a metal salt, wherein the proanthocyanidin dispersion includes proanthocyanidins and a second solvent; mixing the metal salt and the proanthocyanidin dispersion to obtain the complex.

8. The preparation method according to claim 7, characterized in that, The degree of polymerization of the proanthocyanidins is 2 to 10; further, the degree of polymerization of the proanthocyanidins is 2 to 5; and / or The proanthocyanidins contain phenolic hydroxyl groups, and the mass fraction of the phenolic hydroxyl groups in the proanthocyanidins is 25% to 35%; and / or In the proanthocyanidin dispersion, the mass concentration of proanthocyanidins is 10 mg / mL to 30 mg / mL; and / or The second solvent includes a polar solvent, which comprises one or more of the following: trimethoxybutanol, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, tetrahydrofuran, N,N-dimethylformamide, pyrrole, and butyric acid; and / or The metal salt includes a silver salt, which includes one or more of silver chloride, silver nitrate, silver bromide, silver iodide, and silver cyanide; and / or The mass ratio of the proanthocyanidin to the metal salt is (5-15):1; and / or The metal salt and the proanthocyanidin dispersion are mixed at a temperature of 60℃ to 80℃ for a time of 1h to 3h.

9. The preparation method according to claim 6, characterized in that, Mixing the complex and the quantum dot dispersion comprises: providing a complex dispersion comprising the complex and a third solvent; and mixing the complex dispersion and the quantum dot dispersion, wherein... In the quantum dot dispersion, the mass concentration of the quantum dots is 10 mg / mL to 30 mg / mL; and / or In the dispersion of the complex, the mass concentration of the complex is 5 mg / mL to 20 mg / mL; and / or The first solvent includes a nonpolar solvent, which includes one or more of the following: n-hexane, n-heptane, n-octane, isooctane, cyclohexane, benzene, toluene, xylene, ethylbenzene, carbon tetrachloride, chloroform, and dichloromethane; and / or The third solvent includes a polar solvent, comprising one or more of the following: trimethoxybutanol, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, tetrahydrofuran, N,N-dimethylformamide, pyrrole, and butyric acid; and / or The mass ratio of the quantum dot to the complex is (5-15):1; and / or The mixing temperature of the complex dispersion and the quantum dot dispersion is 80℃~90℃, and the mixing time is 30min~60min; and / or The quantum dot is further connected to a ligand; wherein the mass ratio of the quantum dot to the ligand is (10-20):1; and / or, the ligand comprises one or more of the following: aliphatic amine ligands having 1-24 carbon atoms, fatty acid ligands having 1-24 carbon atoms, carboxylate ligands, phosphate ligands, halide ion ligands, thiol ligands having 1-24 carbon atoms, trialiphatic phosphine having 9-30 carbon atoms, triarylphosphine having 18-30 carbon atoms, trialiphatic phosphine oxide having 9-30 carbon atoms, and triarylphosphine oxide having 18-30 carbon atoms.

10. An optoelectronic device, characterized in that, It includes an anode, a light-emitting layer, and a cathode stacked sequentially, wherein the material of the light-emitting layer includes the nanomaterials as described in any one of claims 1 to 5, or the nanomaterials prepared by the preparation method as described in any one of claims 6 to 9.

11. The optoelectronic device as described in claim 10, characterized in that, The thickness of the light-emitting layer is 10 nm to 40 nm; and / or The anode and the cathode each independently include one or more of the following: a metal electrode, a carbon electrode, a metal oxide electrode, and a composite electrode; the material of the metal electrode includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the material of the carbon electrode includes one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO; the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The optoelectronic device further includes an electronic functional layer disposed between the light-emitting layer and the cathode; the electronic functional layer is made of an N-type semiconductor material, which includes one or more of the following: first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials; the first undoped metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5; the metal oxide in the first doped metal oxide particles includes ZnO, TiO2, SnO2, ZrO2, and Ta2O5. One or more of rO2, Ta2O5, and Al2O3, wherein the doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga; the IIB-VIA group semiconductor material includes one or more of ZnS, ZnSe, and CdS; the IIIA-VA group semiconductor material includes one or more of InP and GaP; and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS, wherein the doping amount of the doping element in the first doped metal oxide particle is 0.1wt% to 15wt%; and / or The optoelectronic device further includes a hole functional layer disposed between the anode and the light-emitting layer; the material of the hole functional layer includes organic p-type semiconductor materials or inorganic p-type semiconductor materials, wherein the organic p-type semiconductor materials include 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4’-diamine, and N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4’-diamine. 4,4',4'-Bis(phenyl)-spiro, N,N'-Di(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-Tris(N-carbazolyl)-triphenylamine, 4,4',4'-Tris(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzphenanthrene, 4,4',4'-Tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene- 2,7-dimethyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-)phenylenevinylene, poly(phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene], copper phthalocyanine, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-)phenylenevinylene Carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthyl-1-yl)-N,N'-diphenylbenzidine, spironolactone (NPB), nanocrystalline diamond, microcrystalline cellulose and tetracyanoquinone dimethane, doped graphene, undoped graphene;The inorganic P-type semiconductor material comprises one or more of the following: second-doped metal oxide particles, second-undoped metal oxide particles, metal sulfides, metal selenides, and metal nitrides. The metal oxides in the second-doped and second-undoped metal oxide particles each independently comprise one or more of MoO3, WO3, NiO, CrO3, CuO, and V2O5. The doping element in the second-doped metal oxide particles comprises one or more of Mo, W, Ni, Cr, Cu, and V. The metal sulfide comprises one or more of CuS, MoS3, and WS3. The metal selenide comprises one or more of MoSe3 and WSe3. The metal nitride comprises P-type gallium nitride. The doping amount of the doping element in the second-doped metal oxide particles is 0.1 wt% to 15 wt%.

12. A display device, characterized in that, Including the optoelectronic device as described in any one of claims 10 to 11.

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