Composite material, quantum dot purification method and photoelectric device

Abstract

The invention discloses a composite material, a quantum dot purification method and a photoelectric device, the composite material comprises a carrier and a first compound, the first compound is connected to the surface of the carrier, and the composite material can be used as a stationary phase of column chromatography so as to be applied to purification of quantum dots. The quantum dots with different ligand contents can be screened, and the performance consistency of the quantum dots prepared by a solution method is improved.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technologies, and particularly relates to a composite material, a purification method for quantum dots, and an optoelectronic device. Background Art

[0002] Quantum dots (QDs), also known as semiconductor nanocrystals, are nanocrystals with a radius less than or close to the exciton Bohr radius, and the average particle size is usually between 1 nm and 20 nm. Quantum dots have unique fluorescence nano-effects. The emission wavelength of quantum dots can be regulated by changing their own size and composition, and they have the advantages of a narrow full width at half maximum of the emission spectrum, high color purity, good optical stability, a wide excitation spectrum, and a controllable emission spectrum, and have broad application prospects in technical fields such as photovoltaic power generation, optoelectronic display, and biological probes.

[0003] In related technologies, quantum dots are usually prepared by a solution method. The prepared quantum dots usually have ligands connected to their surfaces. The content of the ligands is one of the key influencing factors for the photoluminescence quantum yield of quantum dots. However, conventional solid-liquid separation and purification methods cannot screen quantum dots with different ligand contents, resulting in uneven ligand contents in the prepared quantum dots, and thus there is a problem of low performance consistency for the quantum dots prepared by the solution method. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present application provides a composite material, a purification method for quantum dots, and an optoelectronic device.

[0005] The technical solution of the present application is as follows:

[0006] In a first aspect, the present application provides a composite material, which includes a carrier and a first compound. The first compound is connected to the surface of the carrier, and the first compound has a structure shown in the following general formula (I):

[0007]

[0008] In the general formula (I), R1 and R2 are independently selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, and a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group;

[0009] R3 is selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group, and a substituted or unsubstituted C1-C30 aliphatic alkoxy group;

[0010] R4 is selected from one or more of substituted or unsubstituted C1-C30 alkylene, substituted or unsubstituted C2-C30 alkenylene, substituted or unsubstituted C2-C30 alkynylene, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C5-C30 heteroarylene, and amide group;

[0011] R5 is selected from amino group or carboxyl group.

[0012] In a second aspect, the present application provides a method for purifying quantum dots, comprising the following steps:

[0013] Providing a separator comprising a stationary phase, the stationary phase comprising the composite material as described in the first aspect, or the composite material prepared by the preparation method of the composite material as described in the second aspect;

[0014] Providing a first solution containing quantum dots, at least part of the quantum dots on the surface of the first solution being connected with a first ligand, the first ligand comprising a first group, passing the first solution through the separator, and the quantum dots with the first ligand connected on the surface being bound to the carrier through the interaction between the first compound and the first ligand; and

[0015] Providing a second solution for inducing the quantum dots to detach from the stationary phase, passing the second solution through the separator so that at least part of the quantum dots bound to the stationary phase flow out of the separator, the lower the content of the first ligand on the surface of the quantum dots, the earlier the time point of flowing out of the separator, and collecting the quantum dots in the target outflow time period;

[0016] One of the first group and R5 of the first compound is an amino group, and the other is a carboxyl group.

[0017] In a third aspect, the present application provides a quantum dot prepared by the purification method as described in the second aspect.

[0018] In a fourth aspect, the present application provides an optoelectronic device, comprising a first electrode and a second electrode arranged oppositely, and a plurality of functional layers arranged between the first electrode and the second electrode, the material of at least one functional layer in the plurality of functional layers comprising the quantum dots prepared by the purification method as described in the second aspect, or the quantum dots as described in the third aspect.

[0019] The present application provides a composite material, a method for purifying quantum dots, and an optoelectronic device, having the following technical effects:

[0020] The composite material includes a carrier and a first compound. The first compound is connected to the surface of the carrier. The composite material can be used as a stationary phase for column chromatography, and thus can be applied to the purification of quantum dots, enabling the screening of quantum dots with different ligand contents and improving the performance consistency of quantum dots prepared by solution methods. Description of the Drawings

[0021] Combined with the drawings below, through a detailed description of the specific embodiments of the present application, the technical solutions and other beneficial effects of the present application will become obvious.

[0022] Figure 1 It is a schematic flowchart of a method for purifying quantum dots provided by an embodiment of the present application.

[0023] Figure 2 It is a schematic structural diagram of the first optoelectronic device provided by an embodiment of the present application.

[0024] The reference numerals are as follows:

[0025] 1: Light-emitting device, 10: Substrate, 11: Anode, 12: Cathode, 13: Active layer, 14: Electron functional layer, 15: Hole functional layer, 151: Hole injection layer, 152: Hole transport layer. Specific Embodiments

[0026] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0027] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are only for illustrative purposes and do not limit the content of the present application.

[0028] It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments. Each embodiment of the present application may exist in a range form; it should be understood that the description in a range form is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual 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 individual numbers within the counted range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0029] In the present application, the term "comprising" means "including but not limited to".

[0030] In the present application, "at least one" means one or more, and "a plurality" means two or more. The term "at least one", "at least one of the following (items)" or similar expressions refer to any combination of these items, including any single (item) or plural (items) combination. For example, "at least one of (item) a, b, or c" or "at least one of (item) a, b, and c" can both be expressed as: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0031] In the present application, the description of "layer A is formed on one side of layer B" or "layer A is formed on the side of layer B away from layer C" can mean that layer A is directly formed on one side of layer B or on the side of layer B away from layer C, that is, layer A is in direct contact with layer B; it can also mean that layer A is indirectly formed on one side of layer B or on the side of layer B away from layer C, that is, other film layers can be formed between layer A and layer B.

[0032] In the present application, the selection range of "and / or" includes any one of two or more related listed items, and also includes any and all combinations of the related listed items. The said any and all combinations include combinations of any two related listed items, any more related listed items, or all related listed items. For example, "A and / or B" includes three parallel solutions: A, B, and A + B. Another example, for the technical solution of "A, and / or, B, and / or, C, and / or, D", it includes any one of A, B, C, D (that is, the technical solutions connected by "logical or"), and also includes any and all combinations of A, B, C, D, that is, it includes combinations of any two or any three of A, B, C, D, and also includes the four - item combination of A, B, C, D (that is, the technical solutions connected by "logical and").

[0033] In the present application, "particle size" refers to the diameter of the nanoparticles.

[0034] In the present application, "substituted or unsubstituted" means that the defined group may be substituted or may not be substituted. When the defined group is substituted, it should be understood that the defined group may be substituted by one or more substituents R, where R is selected from, but not limited to, deuterium atom, cyano group, isocyano group, nitro group, halogen atom, straight-chain alkyl group having 1 to 20 carbon atoms, branched-chain alkyl group or cycloalkyl group having 3 to 20 carbon atoms, aliphatic cycloalkyl group having 3 to 20 ring atoms, heteroalicyclic group having 3 to 20 ring atoms, aromatic group having 6 to 20 ring atoms, heteroaryl group having 5 to 20 ring atoms, -NR’R”, silyl group, carbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, halocarbonyl group, formyl group, isocyanate group, thiocyanate group, isothiocyanate group, hydroxyl group, trifluoromethyl group, and the above groups may also be further substituted by substituents acceptable in the art. It is understood that in -NR’R”, R’ and R” are each independently selected from, but not limited to, hydrogen atom, deuterium atom, cyano group, isocyano group, nitro group, halogen atom, straight-chain alkyl group having 1 to 10 carbon atoms, branched-chain alkyl group or cycloalkyl group having 3 to 10 carbon atoms, aliphatic cycloalkyl group having 3 to 10 ring atoms, heteroalicyclic group having 3 to 10 ring atoms, aromatic group having 6 to 20 ring atoms, heteroaryl group having 5 to 20 ring atoms, silyl group, carbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, halocarbonyl group, formyl group, isocyanate group, thiocyanate group, isothiocyanate group, hydroxyl group, trifluoromethyl group, and the above groups may also be further substituted by substituents acceptable in the art.

[0035] In the present application, hydroxyl group refers to -OH, carboxyl group refers to -COOH, carbonyl group refers to -C(=O)-, formyl group refers to -C(=O)H, halocarbonyl group refers to -C(=O)Z (where Z represents halogen), carbamoyl group refers to -C(=O)NH2, isocyanate group refers to -NCO, isothiocyanate group refers to -NCS. Thioalkoxy group refers to a group having the structure of "-O-S-alkyl". Amino group refers to the group of the above general formula -NR’R”.

[0036] In the present application, "hydrocarbyl" refers to a group formed by removing one hydrogen atom from a hydrocarbon, including alkyl and unsaturated hydrocarbyl groups. Among them, the unsaturated hydrocarbyl group is, for example, selected from one or more of alkenyl and alkynyl groups. The number of carbon atoms in the aliphatic straight-chain hydrocarbyl group can be, for example, 1, 2, 5, 8, 10, 15, 20, 25, 30, or a value between any two of the foregoing values. The number of carbon atoms in the aliphatic branched-chain hydrocarbyl group can be, for example, 3, 4, 5, 8, 10, 15, 20, 25, 30, or a value between any two of the foregoing values. The number of carbon atoms in the aliphatic cyclic hydrocarbyl group can be, for example, 3, 4, 5, 8, 10, 15, 20, 25, 30, or a value between any two of the foregoing values. Among them, non-limiting examples of straight-chain alkyl groups are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, or n-eicosyl; non-limiting examples of branched-chain alkyl groups are isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, tert-octyl, 2-ethyloctyl, 2-butyl octyl, 2-hexyloctyl, 3,7-dimethyloctyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, 2-ethylhexadecyl, or 2-butylhexadecyl; non-limiting examples of cycloalkyl groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, or adamantyl.

[0037] It can be understood that "alkylene" refers to a group formed by removing two hydrogen atoms from an alkane molecule, "alkenylene" refers to a group formed by removing two hydrogen atoms from an alkene molecule, and "alkynylene" refers to a group formed by removing two hydrogen atoms from an alkyne molecule.

[0038] In the present application, "aliphatic chain alkoxy" refers to a group with the general formula R0-O-*, where R0 is selected from C1-C30 aliphatic straight-chain hydrocarbyl groups, C3-C30 aliphatic branched-chain hydrocarbyl groups, or C3-C30 aliphatic cyclic hydrocarbyl groups.

[0039] In the present application, "aryl" refers to an aromatic hydrocarbon group derived by removing one hydrogen atom from an aromatic ring compound, which can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For a polycyclic ring, at least one is an aromatic ring system. "Substituted or unsubstituted C6-C30 aryl" can be an aryl having 6 to 28 ring atoms, an aryl having 6 to 24 ring atoms, an aryl having 6 to 20 ring atoms, an aryl having 6 to 18 ring atoms, an aryl having 6 to 16 ring atoms, an aryl having 6 to 14 ring atoms, or an aryl having 6 to 10 ring atoms. The number of ring atoms can be, for example, 6, 10, 12, 14, 18, 20, 30, or a value between any two of the foregoing values. Suitable examples include but are not limited to phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, or phenanthryl. It can be understood that "arylene" refers to an aromatic hydrocarbon group derived by removing two hydrogen atoms from an aromatic ring compound.

[0040] In the present application, "heteroaryl" refers to a group in which at least one carbon atom in the aryl is replaced by a non-carbon atom, and the non-carbon atom can be an N atom, an O atom, an S atom, etc. "Substituted or unsubstituted C5-C30 heteroaryl" can be a heteroaryl having 5 to 28 ring atoms, a heteroaryl having 5 to 24 ring atoms, a heteroaryl having 5 to 20 ring atoms, a heteroaryl having 5 to 18 ring atoms, a heteroaryl having 5 to 16 ring atoms, a heteroaryl having 5 to 14 ring atoms, or a heteroaryl having 5 to 10 ring atoms. The number of ring atoms can be, for example, 5, 10, 12, 14, 18, 20, 30, or a value between any two of the foregoing values. Suitable examples include but are not limited to thienyl, furyl, pyrrolyl, dioxolyl, triazolyl, imidazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, benzothienyl, benzofuryl, indolyl, pyrroloimidazolyl, pyrrolopyrrolyl, thienopyrrolyl, thienothienyl, furanopyrrolyl, furanofuryl, thienofuryl, benzisoxazolyl, benzisothiazolyl, benzimidazolyl, phthalazinyl, phenanthridinyl, peridinyl, quinazolinone, dibenzothienyl, dibenzofuryl, or carbazolyl. It can be understood that "heteroarylene" refers to a group formed by removing one hydrogen atom from the heteroaryl.

[0041] An embodiment of the present application provides a composite material, which includes a carrier and a first compound. The first compound is connected to the surface of the carrier, and the first compound has a structure represented by the following general formula (I):

[0042]

[0043] In general formula (I), R1 and R2 are each independently selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, and a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group. Further, R1 and R2 are each independently selected from one or more of a substituted or unsubstituted C1-C10 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C10 aliphatic branched-chain hydrocarbon group, and a substituted or unsubstituted C3-C10 aliphatic cyclic hydrocarbon group; optionally, R1 and R2 are each independently selected from a C1-C10 straight-chain alkyl group, a C3-C10 branched-chain alkyl group, or a C3-C10 cyclic alkyl group. Still further, R1 and R2 are each independently selected from a C1-C6 straight-chain alkyl group, a C3-C6 branched-chain alkyl group, or a C3-C6 cyclic alkyl group. In at least one embodiment of the present application, R1 and R2 are each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl.

[0044] In general formula (I), R3 is selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group, and a substituted or unsubstituted C1-C30 aliphatic chain alkoxy group. Further, R3 is selected from one or more of a substituted or unsubstituted C1-C10 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C10 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C10 aliphatic cyclic hydrocarbon group, and a substituted or unsubstituted C1-C10 aliphatic chain alkoxy group. Still further, R3 is selected from a C1-C10 straight-chain alkyl group, a C3-C10 branched-chain alkyl group, a C3-C10 cyclic alkyl group, or a C1-C10 alkoxy group. Still further, R3 is selected from a C1-C6 straight-chain alkyl group, a C3-C6 branched-chain alkyl group, a C3-C6 cyclic alkyl group, or a C1-C6 alkoxy group. In at least one embodiment of the present application, R3 is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, methoxy, or ethoxy.

[0045] In general formula (I), R4 is selected from one or more of substituted or unsubstituted C1-C30 alkylene, substituted or unsubstituted C2-C30 alkenylene, substituted or unsubstituted C2-C30 alkynylene, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C5-C30 heteroarylene, and amide group. Further, R4 is selected from one or more of substituted or unsubstituted C1-C10 alkylene, substituted or unsubstituted C2-C10 alkenylene, substituted or unsubstituted C2-C10 alkynylene, substituted or unsubstituted C6-C18 arylene, substituted or unsubstituted C5-C18 heteroarylene, and amide group. Still further, R4 is selected from one or more of C1-C6 alkylene, C2-C6 alkenylene, C2-C6 alkynylene, C6-C14 arylene, C5-C14 heteroarylene, and amide group. In at least one embodiment of the present application, R4 is selected from - (CH2) n - (where n is a positive integer from 1 to 6), - (CH = CH) m - (where n is a positive integer from 1 to 6), and one or more of amide groups.

[0046] In general formula (I), R5 is selected from amino group or carboxyl group.

[0047] In some embodiments of the present application, the first compound is selected from one or more of 3-aminopropyltriethoxysilane (CAS No. 919-30-2), (3-aminopropyl) trimethoxysilane (CAS No. 13822-56-5), 3-aminopropyl (diethoxy) methylsilane (CAS No. 3179-76-8), and 3-[3-carboxyacrylamido] propyltriethoxysilane (CAS No. 50488-14-7).

[0048] In the composite material, the carrier can be granular, flaky or strip-shaped, and the carrier can be a substance or a composition. Suitable carriers include, but are not limited to, one or more of silica gel, aluminum oxide, titanium oxide, iron oxide, copper oxide, and zinc oxide. In some embodiments of the present application, the carrier is granular, and the mesh number of the carrier is 100 mesh to 300 mesh, for example, it can be 100 mesh, 200 mesh, 300 mesh, or a value between any two of the foregoing values. In at least one embodiment of the present application, the carrier is a support for solid-phase purification.

[0049] In some embodiments of the present application, the mass ratio of the carrier to the first compound is 100:(0.5 - 2), for example, it can be 100:0.5, 100:0.8, 100:1, 100:1.2, 100:1.5, 100:1.7, 100:2, or a value between any two of the foregoing ratios.

[0050] The embodiments of the present application also provide a method for preparing a composite material, which can be used to prepare any of the composite materials described above. The method for preparing the composite material includes the steps of: mixing a carrier and a first compound to obtain a composite material. Wherein, both the carrier and the first compound are as described above.

[0051] In some embodiments of the present application, in the step of mixing the carrier and the first compound, the mass ratio of the carrier to the first compound is 100:(0.5 - 2), for example, it can be 100:0.5, 100:0.8, 100:1, 100:1.2, 100:1.5, 100:1.7, 100:2 or a value between any two of the foregoing ratios.

[0052] The embodiments of the present application also provide a separator, which includes a stationary phase, and the stationary phase includes any of the composite materials described above, or a composite material prepared by the method for preparing any of the composite materials described above.

[0053] In some embodiments of the present application, the separator is columnar. Optionally, the separator is a chromatography column.

[0054] The embodiments of the present application provide a method for purifying quantum dots, as Figure 1 shown, including the following steps:

[0055] S1. Provide a separator including a stationary phase, and the stationary phase includes any of the composite materials described above, or a composite material prepared by the method for preparing any of the composite materials described above;

[0056] S2. Provide a first solution containing quantum dots, and at least part of the quantum dots on the surface of the first solution are connected with a first ligand. The first ligand includes a first group. Pass the first solution through the separator, and the quantum dots with the first ligand connected to the surface thereof are combined with the carrier through the interaction between the first compound and the first ligand;

[0057] S3. Provide a second solution for inducing the quantum dots to detach from the carrier, and pass the second solution through the separator so that at least part of the quantum dots combined with the carrier flow out of the separator. The lower the content of the first ligand on the surface of the quantum dots, the earlier the time point of flowing out of the separator. Collect the quantum dots in the target outflow time period.

[0058] Wherein, one of the first group and the R5 of the first compound is an amino group, and the other is a carboxyl group, so that an interaction can occur between R5 and the first group. It should be noted that the carboxyl group ionizes to generate H + ,H + will combine with the amino group to make the nitrogen atom in the amino group carry a positive charge, and the carboxyl group loses H +It is negatively charged itself, so as to cause an interaction between R5 and the first group.

[0059] In the purification method of the quantum dots according to the embodiments of the present application, since the surface of the carrier is connected with a first compound, and the first compound can interact with the first ligand on the surface of the quantum dots, the binding tightness between the quantum dots and the carrier is enhanced. The higher the content of the first ligand on the surface of the quantum dots, the stronger the binding tightness between the quantum dots and the carrier, and the later it flows out of the separator in the elution separation process, so as to realize the screening of quantum dots with different ligand contents and improve the performance consistency of the quantum dots prepared by the solution method. It should be noted that the interaction between the first compound and the first ligand is the interaction of positive and negative charges and hydrogen bonds.

[0060] In some embodiments of the present application, the first group is a carboxyl group, and the first compound is selected from one or more of 3-aminopropyltriethoxysilane, (3-aminopropyl)trimethoxysilane, and 3-aminopropyl(diethoxy)methylsilane.

[0061] In some other embodiments of the present application, the first group is an amino group, and the first compound is selected from 3-[3-carboxyacrylamido]propyltriethoxysilane.

[0062] In step S1, a stationary phase can be first formed outside the separator and then fixed in the separator, or a stationary phase can be formed inside the separator. In some embodiments of the present application, step S1 includes the steps of: providing a separator loaded with a carrier and a third solution including a first compound, adding the third solution to the separator to soak the carrier in the third solution, and then removing the free first compound. The solvent of the third solution includes but is not limited to water.

[0063] Further, in some embodiments of the present application, the step of providing a separator loaded with a carrier includes: mixing a first organic solvent and a carrier to obtain a mixture, adding the mixture to the separator, and then rinsing the separator with the first organic solvent, wherein the first organic solvent is selected from one or more of aliphatic hydrocarbons having 6 to 18 carbon atoms and aromatic hydrocarbons having 6 to 20 ring atoms with or without substitution. The number of carbon atoms of the aliphatic hydrocarbon is, for example, 6 to 8, 6 to 10, 6 to 12, 6 to 16, or 10 to 18. The aliphatic hydrocarbon includes, but is not limited to, one or more of n - hexane, n - heptane, n - octane, n - nonane, n - decane, 1 - hexene, and 1 - octene. The number of ring atoms of the aromatic hydrocarbon is, for example, 6 to 10, 6 to 14, 6 to 16, 6 to 18, or 10 to 20. The aromatic hydrocarbon includes, but is not limited to, one or more of toluene, benzene, and mesitylene. It should be noted that the mass of the carrier can be 15 to 20 times the mass of the first solution to ensure a good purification effect. In the step of rinsing the separator with the first organic solvent, the separator is rinsed under pressurized conditions (the pressure is, for example, 0.1 MPa to 0.3 MPa). It can be understood that during the process of adding the mixture to the separator and rinsing the separator with the first organic solvent, it is necessary to ensure the uniformity of the mixture filling, and problems such as stratification and the presence of bubbles should not occur.

[0064] Further, in some embodiments of the present application, in order to increase the grafting rate of the first compound on the surface of the solid matrix, and to improve the problem of self - polymerization of the first compound caused by an excessive amount of the first compound, thereby further improving the purification effect and facilitating the control of the dosage of the first compound to save the purification cost, in some embodiments of the present application, in the step of adding the third solution to the separator to soak the carrier in the third solution, the mass ratio of the carrier to the first compound in the third solution is 100:(0.5 to 2), for example, it can be 100:0.5, 100:0.8, 100:1, 100:1.2, 100:1.5, 100:1.7, 100:2, or a value between any two of the foregoing ratios.

[0065] Further, in some embodiments of the present application, the step of removing the free first compound includes: passing the second solution through the separator so that the free first compound flows out of the separator.

[0066] In step S2, the first solution can be the product obtained by preparing quantum dots using the solution method, or the substance obtained after preliminary separation and purification of the product. In the first solution, the concentration of the quantum dots is, for example, 10 mg / mL to 100 mg / mL.

[0067] In some embodiments of the present application, the general formula of the first ligand is Rs-Rt, where Rt is selected from an amino group or a carboxyl group, and Rs is selected from a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C5-C30 heteroaryl group, or R7-R6-*, where * represents the connection site of Rs and Rt, R7 is selected from an amino group, a carboxyl group, a mercapto group, or a hydroxyl group, and R6 is selected from one or more of a substituted or unsubstituted C1-C30 alkylene group, a substituted or unsubstituted C2-C30 alkenylene group, a substituted or unsubstituted C2-C30 alkynylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C5-C30 heteroarylene group.

[0068] Optionally, Rs is selected from a substituted or unsubstituted C1-C10 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C10 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C10 aliphatic cyclic hydrocarbon group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, or R7-R6-*, R7 is selected from an amino group or a carboxyl group, and R6 is selected from one or more of a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, and a substituted or unsubstituted C5-C20 heteroarylene group.

[0069] In some embodiments of the present application, the first ligand is selected from aliphatic polyacid compounds having 3 to 30 carbon atoms or aliphatic polyamine compounds having 3 to 30 carbon atoms; optionally, the aliphatic polyacid compounds are selected from one or more of caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, arachidonic acid, erucic acid, and docosahexaenoic acid, and the aliphatic polyamine compounds are selected from one or more of hexylamine, octylamine, dioctylamine, trioctylamine, nonylamine, decylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, and oleylamine.

[0070] In some embodiments of the present application, the preparation method of the first solution includes the following steps:

[0071] A1. React a mixed solution containing a cationic precursor and an anionic precursor to obtain a reaction product containing nanoparticles;

[0072] A2. Mix the reaction product containing nanoparticles, the first organic solvent and the third organic solvent to obtain a mixed system, and then perform solid-liquid separation on the mixed system. After discarding the supernatant, a solid separation is obtained;

[0073] A3. Disperse the solid separation in a non-polar solvent to obtain a quantum dot solution.

[0074] In step A1, the cationic precursor includes one or more of a cadmium source, a zinc source, an indium source, a copper source, and a silver source; the anionic precursor includes one or more of a selenium source, a sulfur source, a tellurium source, and a phosphorus source. It can be understood that the cationic precursor and the anionic precursor can be selected according to the type of quantum dots actually prepared. For example, when the quantum dots actually prepared are CdSe, the corresponding cationic precursor is a cadmium source, and the corresponding anionic precursor is a selenium source.

[0075] In some embodiments of the present application, the nanoparticles include single-component quantum dots or core-shell structure quantum dots. The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are respectively selected from at least one of II-VI group compounds, IV-VI group compounds, III-VI group compounds, III-V group compounds, and I-III-VI group compounds. Among them, the II-VI group compounds include, 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, and / or the IV-VI group compounds include, 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, and / or the III-V group compounds include, 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, and / or the III-VI group compounds are selected from one or more of In2S3, In2Se3, InGaS3, and InGaSe3, and / or the I-III-VI group compounds include, but are not limited to, one or more of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2, AgInGaS2, and CuInGaS2.As an example, the core-shell structured quantum dots can be selected from, but 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.

[0076] It should be noted that for the materials of the aforementioned single-structured quantum dots, or the core materials of the core-shell structured quantum dots, or the shell materials of the core-shell structured quantum dots, the provided chemical formulas only indicate the elemental composition and do not indicate the content of each element. For example, CdZnSe only indicates that it is composed of three elements, Cd, Zn, and Se. If the content of each element is to be indicated, it corresponds to Cd x Zn 1-x Se, where 0 < x < 1.

[0077] It can be understood that in some embodiments of the present application, when the nanoparticles are single-component quantum dots, the single-component quantum dots can be obtained through step SA1. If the mixed solution in step A1 does not include the first ligand, a ligand exchange reaction is carried out to connect the first ligand to the surface of the quantum dots.

[0078] In some other embodiments of the present application, when the nanoparticles are the core-shell structured quantum dots with n + 1 shell layers, after the step of reacting the mixed system containing the cation precursor and the anion precursor, and before the step of obtaining the reaction product containing the nanoparticles, the method for preparing the quantum dot solution further includes the steps of: forming a core solution containing the quantum dot core; and forming n + 1 shell layers on the surface of the quantum dot core, where n is an integer greater than or equal to 0. As an example, the preparation method for each shell layer includes the steps of: providing a shell layer cation source and a shell layer anion source for the shell layer to be prepared, adding the shell layer cation source and the shell layer anion source to the solution obtained in the previous step, and carrying out a reaction to form one shell layer. The shell layer cation source includes, but is not limited to, one or more of cadmium sources, zinc sources, indium sources, copper sources, and silver sources, and the shell layer anion source includes one or more of selenium sources, sulfur sources, tellurium sources, and phosphorus sources.

[0079] In step A2, the purpose of mixing the reaction product containing nanoparticles, the first organic solvent, and the third organic solvent is to precipitate the nanoparticles in the reaction product and remove part of the cationic precursor. Therefore, when the reaction product containing nanoparticles is mixed with the first organic solvent and the third organic solvent, a flocculent precipitate will appear. The first organic solvent is as described above. The third organic solvent is selected from alcohols having 1 to 10 carbon atoms, and the third organic solvent includes, but is not limited to, one or more of methanol, ethanol, propanol, butanol, pentanol, and hexanol.

[0080] In order to balance improving the yield of quantum dots and reducing the risk of "aggregation" of quantum dots, in some embodiments of the present application, in step A2, the volume ratio of the reaction product containing nanoparticles: the first organic solvent: the third organic solvent is 1:(0.25 - 0.5):(0.5 - 1). As an example, the volume ratio of the reaction product containing nanoparticles: the first organic solvent is 1:0.25, 1:0.3, 1:0.4, 1:0.5, and values between any two of the above-listed values; the volume ratio of the reaction product containing nanoparticles: the second organic solvent is 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, and values between any two of the above-listed values.

[0081] In order to further improve the removal rate of the cationic precursor in step A2 and ensure the safety during the preparation process, in some embodiments of the present application, in the step of mixing the reaction product containing nanoparticles, the first organic solvent, and the third organic solvent, the temperature of the reaction product containing nanoparticles is 120°C to 160°C, such as 120°C, 130°C, 140°C, 150°C, 160°C, and values between any two of the above-listed values, so as to increase the solubility of the residual cationic precursor in the quantum dots in the first organic solvent and the second organic solvent.

[0082] Continuing to look at step A2, the solid-liquid separation includes, but is not limited to, one or more of sedimentation treatment, filtration treatment, and drying treatment. Among them, the sedimentation treatment includes, but is not limited to, one or more of gravitational sedimentation, centrifugal sedimentation, and electromagnetic sedimentation. The filtration treatment includes, but is not limited to, one or more of reverse osmosis, membrane filtration, nanofiltration, ultrafiltration, and microfiltration. The drying treatment includes, but is not limited to, one or more of heat treatment and irradiation treatment. It can be understood that the operation of the solid-liquid separation can be carried out once or more than twice.

[0083] In order to further improve the removal rate of the cationic precursor in step A2, in some embodiments of the present application, in the step of performing solid-liquid separation on the mixed system, the temperature of the mixed system is 80°C to 100°C. The temperature of the mixed system can be, for example, 60°C, 65°C, 70°C, 75°C, 80°C, and values between any two of the above-listed values.

[0084] In some embodiments of the present application, the second solution in step S3 includes one or more of a first organic solvent and a second organic solvent. The first organic solvent is as described above. The general formula of the second organic solvent is R8COOR9, where R8 and R9 are independently selected from straight-chain alkyl groups of C1 to C8. For example, R8 and R9 are independently selected from straight-chain alkyl groups of C1 to C6, straight-chain alkyl groups of C1 to C5, or straight-chain alkyl groups of C1 to C3. The second organic solvent includes, but is not limited to, one or more of ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, and butyl acetate.

[0085] In order to further improve the purification effect of the quantum dots, in some embodiments of the present application, the second solution is composed of a first organic solvent and a second organic solvent. The volume ratio of the first organic solvent to the second organic solvent is 1:(0.1 - 1), for example, 1:0.1, 1:0.3, 1:0.5, 1:0.8, 1:1, or a value between any two of the foregoing ratios. If the content of the first organic solvent is too small, there may be a problem that the quantum dots cannot be completely dissolved in the second solution, and quantum dot precipitation may occur during the chromatography process. If the content of the first organic solvent is too large, the outflow rate of the quantum dots is relatively fast, which may increase the deviation of the analysis effect.

[0086] In some embodiments of the present application, the step of collecting the quantum dots in the target outflow time period includes: obtaining the photoluminescence quantum yield of the quantum dots flowing out from the separator, and collecting the quantum dots flowing out within the corresponding time period according to the target photoluminescence quantum yield. It should be noted that the quantum dots with the required photoluminescence quantum yield can be collected according to the application scenario of the quantum dots. In some application scenarios, a higher photoluminescence quantum yield of the quantum dots is required, and in some application scenarios, a lower photoluminescence quantum yield of the quantum dots is required. For example, quantum dots with a photoluminescence quantum yield of not less than 85% can be collected.

[0087] The embodiments of the present application also provide a kind of quantum dots, which are prepared by any one of the purification methods described above, and the quantum dots have high performance consistency. The composition of the quantum dots can be referred to the description of the nanoparticles above.

[0088] In some embodiments of the present application, the photoluminescence quantum yield of the quantum dots is not less than 85%, for example, not less than 87%, not less than 90%, not less than 92% or not less than 95%; and / or, the molar amount of the first ligand located on the surface of the quantum dots is not less than 12% of the total molar amount of the quantum dots, for example, not less than 13% of the total molar amount of the quantum dots, not less than 15% of the total molar amount of the quantum dots or not less than 20% of the total molar amount of the quantum dots.

[0089] In some embodiments of the present application, the average particle size of the quantum dots is 1 nm to 20 nm, for example, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, and values between any two of the above-listed values.

[0090] Embodiments of the present application also provide an optoelectronic device, which includes but is not limited to a light-emitting device, a photovoltaic cell or a photodetector. As Figure 2 shown, the optoelectronic device 1 includes a first electrode 11, a second electrode 12, and a plurality of functional layers. The first electrode 11 and the second electrode 12 are disposed opposite to each other, and the plurality of functional layers are disposed between the first electrode 11 and the second electrode 12. The material of at least one of the plurality of functional layers includes quantum dots prepared by any one of the purification methods described above, or quantum dots described in any one of the above.

[0091] In the optoelectronic device 1 of the embodiments of the present application, since the quantum dots are prepared by any one of the purification methods described above, the quantum dots have high performance consistency, can improve the performance stability of the optoelectronic device, and are beneficial to improving the performance consistency of optoelectronic devices between different batches.

[0092] In some embodiments of the present application, the materials of the first electrode 11 and the second electrode 12 are independently selected from one or more of metals, carbon materials, and third metal oxides. Among them, the metals include but are not limited to one or more of Al, Ag, Cu, Mo, Au, Ba, Pt, Ca, Ir, Ni, and Mg. The carbon materials include but are not limited to one or more of graphite, carbon nanotubes, graphene, and carbon fibers. The third metal oxide can be doped or undoped. The doped third metal oxides include but are not limited to one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), and magnesium-doped zinc oxide (MZO). The undoped third metal oxides include but are not limited to one or more of TiO2, SnO2, ZnO, and In2O3.

[0093] In some embodiments of the present application, continue to refer to Figure 2 , the multiple functional layers include an active layer 13, and the material of the active layer 13 includes quantum dots prepared by any one of the purification methods described above, or quantum dots described by any one of the above. It can be understood that when the optoelectronic device 1 is a light-emitting device, the active layer 13 is a light-emitting layer; when the optoelectronic device 1 is a solar cell, the active layer 13 is an absorption layer.

[0094] In some embodiments of the present application, the average thickness of the active layer 13 is 10 nm to 100 nm.

[0095] The first electrode 11 and the second electrode 12 can also be composite electrodes respectively. The composite electrode has a structure similar to a "sandwich", and the materials of the upper layer and the bottom layer are doped or undoped third metal oxides respectively, and the material of the middle layer is a metal. Examples are one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. The thicknesses of the first electrode 11 and the second electrode 12 are, for example, independently selected from 20 nm to 300 nm.

[0096] In order to further improve the comprehensive performance of the optoelectronic device 1, one of the first electrode 11 and the second electrode 12 is an anode, and the other is a cathode. The optoelectronic device 1 further includes an electron functional layer disposed between the cathode and the active layer 13. Taking the first electrode 11 as the anode and the second electrode 12 as the cathode as an example, continue to refer to Figure 2 , the optoelectronic device 1 further includes an electron functional layer 14 disposed between the second electrode 12 and the active layer 13.

[0097] The electron functional layer 14 can be a single-layer structure or a multi-layer structure; when the electron functional layer 14 is a multi-layer structure, the electron functional layer 14 includes, for example, one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. For the electron functional layer 14 including an electron injection layer, an electron transport layer, and a hole blocking layer, the electron transport layer is located between the electron injection layer and the hole blocking layer, and the electron injection layer is closer to the cathode than the hole blocking layer, and the hole blocking layer is closer to the active layer 13 than the electron injection layer. The thickness of the electron functional layer 14 is, for example, 10 nm to 200 nm.

[0098] Among them, the electronic functional layer 14 includes one or more of an undoped first inorganic compound and a doped second inorganic compound. Among them, the undoped first inorganic compound includes one or more of an undoped first metal oxide, a IIB-VIA group semiconductor material, a IIIA-VA group semiconductor material, and a IB-IIIA-VIA group semiconductor material. The undoped first metal oxide includes, but is not limited to, one or more of ZnO, TiO2, SnO2, BaO, Ta2O3, Al2O3, and ZrO2, and / or the IIB-VIA group semiconductor material includes, but is not limited to, one or more of ZnS, ZnSe, and CdS, and / or the IIIA-VA group semiconductor material includes, but is not limited to, one or more of InP and GaP, and / or the IB-IIIA-VIA group semiconductor material includes, but is not limited to, one or more of CuInS and CuGaS.

[0099] The doped second inorganic compound includes a second metal oxide doped with a first doping element. The second metal oxide includes, but is not limited to, one or more of ZnO, TiO2, SnO2, BaO, Ta2O3, Al2O3, and ZrO2. The first doping element includes, but is not limited to, one or more of Mg, Ca, Zr, W, Ga, Li, Al, Ti, Y, In, and Sn. The molar percentage of the first doping element in the doped second inorganic compound is, for example, not higher than 5%, not higher than 10%, not higher than 20%, not higher than 30%, or not higher than 50%. The doped second inorganic compound includes, but is not limited to, one or more of magnesium zinc oxide, calcium zinc oxide, zirconium zinc oxide, gallium zinc oxide, aluminum zinc oxide, lithium zinc oxide, titanium zinc oxide, yttrium zinc oxide, indium tin oxide, and lithium titanium oxide. Examples are Zn (1-x) Mg x O, Zn (1-x) Ca x O, Zn (1-x) Zr x O, Zn (1-x) Ga x O, Zn (1-x) Al x O, Zn (1-x) Li x O, Al (1-x) Zn x O, Zn (1-x) Ti x O, Zn (1-x) Y x O, In (1-x) Sn x O and Ti (1-x) Li x O, and one or more of them, where 0 < x ≤ 0.5.

[0100] It should be noted that when the electronic functional layer 14 includes multiple materials and the electronic functional layer 14 is a multi-layer structure, all of the multiple materials may be in the same layer, or in different layers respectively, or part of them may be in the same layer. As an example, as Figure 2 shown, the electronic functional layer 14 is a single-layer structure, and the electronic functional layer 14 is an electron transport layer.

[0101] In order to further improve the optoelectronic performance and device life of the optoelectronic device 1, in some embodiments of the present application, one of the first electrode 11 and the second electrode 12 is an anode, and the other is a cathode. The optoelectronic device 1 further includes a hole functional layer disposed between the anode and the active layer 13. Taking the first electrode 11 as the anode and the second electrode 12 as the cathode as an example, continue to refer to Figure 2 , the optoelectronic device 1 further includes a hole functional layer 15 disposed between the first electrode 11 and the active layer 13.

[0102] The hole functional layer 15 may be a single-layer structure or a multi-layer structure. The hole functional layer 15 includes, for example, one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. For the hole functional layer 15 including a hole injection layer, a hole transport layer, and an electron blocking layer, the hole injection layer, the hole transport layer, and the electron blocking layer may be sequentially disposed, and the hole injection layer is closer to the first electrode 11 than the electron blocking layer. The thickness of the hole functional layer 15 is, for example, 10 nm to 200 nm.

[0103] Among them, the material of the hole functional layer 15 includes, but is not limited to, one or more of an undoped third inorganic compound, a doped fourth inorganic compound, and an organic compound. Among them, the organic compound includes, but is not limited to, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (abbreviation: PEDOT:PSS, CAS No. 155090-83-8), copper phthalocyanine (CAS No. 147-14-8), titanium oxyphthalocyanine (CAS No. 26201-32-1), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (CAS No. 29261-33-4), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (CAS No. 105598-27-4), polyaniline (CAS No. 25233-30-1), polypyrrole (CAS No. 30604-81-0), 3-hexyl-substituted polythiophene (CAS No. 104934-50-1), poly(9-vinylcarbazole) (abbreviation: PVK, CAS No. 25067-59-8), 4,4'-bis(9-carbazolyl)biphenyl (abbreviation: CBP, CAS No. 58328-31-7), poly[bis(4-phenyl)(4-butylphenyl)amine], 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (abbreviation: TAPC, CAS No. 58473-78-2), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (abbreviation: TFB, CAS No. 220797-16-0), poly[(N,N'-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-ALT-(9,9-din-octylfluorene-2,7-diyl)] (CAS No. 223569-31-1), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (CAS No. 124729-98-2), 4,4',4”-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA, CAS No. 139092-78-7), 4,4',4'-tris(2-naphthylphenylamino)triphenylamine (CAS No. 185690-41-9), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (abbreviation: NPB, CAS No. 123847-85-8), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (abbreviation: TPD, CAS No. 65181-78-4), N,N'-bis[4-(diphenylamino)phenyl]-N,N'-diphenylbenzidine (CAS No. 209980-53-0), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-9,9-spirobifluorene-2,7-diamine (abbreviation: Spiro-TPD,One or more of: 1033035-83-4), N2,N7-di-1-naphthyl-N2,N7-diphenyl-9,9'-spirobi[9H-fluorene]-2,7-diamine (CAS No. 932739-76-9), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (abbreviation PTTA, CAS No. 1333317-99-9), and 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (abbreviation Spiro-omeTAD, CAS No. 207739-72-8); and / or, the non-doped third inorganic compound includes but is not limited to one or more of graphene, C60, nickel oxide (such as NiO), molybdenum oxide (such as MoO3), tungsten oxide (such as WO3), vanadium oxide (such as V2O5), p-type gallium nitride, chromium oxide (such as Cr2O3), copper oxide (such as CuO or Cu2O), copper sulfide (such as CuS), molybdenum sulfide (such as MoS2), and tungsten sulfide (such as WS2); and / or, the doped fourth inorganic compound is a host inorganic compound doped with a second doping element, and the host inorganic compound includes but is not limited to one or more of graphene, C60, nickel oxide (such as NiO), molybdenum oxide (such as MoO3), tungsten oxide (such as WO3), vanadium oxide (such as V2O5), p-type gallium nitride, chromium oxide (such as Cr2O3), copper oxide (such as CuO or Cu2O), copper sulfide (such as CuS), molybdenum sulfide (such as MoS2), and tungsten sulfide (such as WS2), and / or the second doping element includes but is not limited to one or more of nickel, molybdenum, tungsten, vanadium, chromium, copper, and platinum group metal elements.,

[0104] It can be understood that when the hole functional layer 15 contains multiple materials and the hole functional layer 15 is a multilayer structure, the multiple materials can all be in the same layer, or in different layers respectively, or partially in the same layer. For example, as Figure 2 shown, when the hole functional layer 15 is composed of a hole injection layer and a hole transport layer arranged in a stacked manner, the materials of the hole functional layer 15 include PEDOT:PSS and TFB, PEDOT:PSS and TFB are in different layers respectively, the material of the hole injection layer is PEDOT:PSS, and the material of the hole transport layer is TFB.,

[0105] It should be noted that the preparation methods of the various film layers in the optoelectronic device 1 include, but are not limited to, chemical methods and / or physical methods. Among them, the chemical methods include, but are not limited to, one or more of chemical vapor deposition, sequential ionic layer adsorption and reaction, anodic oxidation, electrolytic deposition, and coprecipitation. The physical methods include, but are not limited to, physical coating methods and solution methods. The physical coating methods include, but are not limited to, one or more of thermal evaporation coating, electron beam evaporation coating, magnetron sputtering, multi-arc ion coating, physical vapor deposition, atomic layer deposition, and pulsed laser deposition. The solution methods include, but are not limited to, one or more of spin coating, printing, inkjet printing, blade coating, printing, dip coating, immersion, spraying, roll coating, casting, slot die coating, and bar coating. After the preparation of the various film layers of the optoelectronic device 1 is completed, a packaging process is also required. The packaging process can be carried out by using common machine packaging or manual packaging. In the environment of the packaging process, the oxygen content and the water content are both lower than 0.1 ppm to ensure the performance stability of the optoelectronic device.

[0106] The embodiment of the present application also provides an electronic device, which includes the optoelectronic device described in any one of the embodiments of the present application. The electronic device can be, for example, any electronic product with a display function, including but not limited to a smartphone, a tablet personal computer, a mobile phone, a video telephone, an e-book reader, a laptop PC, a netbook computer, a workstation, a server, a personal digital assistant, a portable multimedia player, an MP3 player, a mobile medical device, a camera, a game console, a digital camera, a car navigator, an electronic billboard, an automated teller machine, a smart bracelet, a smart watch, a Virtual Reality (VR) device, or a wearable device.

[0107] The technical solutions and technical effects of the present application will be described in detail below through specific examples, comparative examples, and experimental examples. The following examples are only partial examples of the present application and do not specifically limit the present application.

[0108] Example 1

[0109] This embodiment provides a method for preparing quantum dots and the prepared quantum dots. The quantum dots are CdSe quantum dots. The emission wavelength of the CdSe quantum dots is 610 nm, the full width at half maximum is 27 nm, the emission color is red, and oleic acid ligands are connected to the surface of the CdSe quantum dots. The method for preparing the quantum dots includes the following steps:

[0110] S1.1. Add 34 mg of cadmium oxide, 16 mL of oleic acid, and 16 mL of 1-octadecene to a 100 mL three-necked flask, then heat to 200 °C under an argon atmosphere until the cadmium oxide is completely dissolved, and naturally cool to room temperature to obtain a cadmium oleate solution;

[0111] S1.2. Add 15 mg of selenium powder to the cadmium oleate solution prepared in step S1.1, then bubble argon through for 20 min, stop bubbling and keep the reaction system under an argon atmosphere, then heat the reaction system to 200 °C and react at 200 °C for 1.5 h, and naturally cool to room temperature to obtain a reaction product;

[0112] S1.3. At room temperature, mix 30 mL of ethanol with all the reaction products prepared in step S1.2 to obtain a mixture, then centrifuge the mixture at a speed of 8000 r / min for 3 min. After discarding the supernatant, add 5 mL of n-hexane to redissolve and disperse the solid, then add 5 mL of ethanol, and centrifuge again at a speed of 8000 r / min for 3 min. After discarding the supernatant, add 0.6 mL of n-octane and disperse evenly to obtain a quantum dot-n-octane solution with a concentration of 100 mg / mL. The average photoluminescence quantum yield of the quantum dots in the quantum dot-n-octane solution is 81%;

[0113] S1.4. Filling and pretreatment of the chromatography column: Mix an excessive amount of n-octane and silica gel (the silica gel is completely immersed in n-octane) and stir evenly. After sufficient adsorption, add it to the chromatography column (with a specification of 10 cm in length × 1 cm in inner diameter) while stirring, and then wash the chromatography column with n-octane under pressure (pressure is 0.2 MPa). During the whole process, it is necessary to ensure uniform loading, no stratification, no bubbles, and the chromatography column does not dry out; then, add an aqueous solution of 3-aminopropyltriethoxysilane with a mass percentage of 2% to the chromatography column until the mass ratio of silica gel to 3-aminopropyltriethoxysilane is 100:1, so that the chromatography column is immersed in the aqueous solution of 3-aminopropyltriethoxysilane. After the silica gel surface is fully grafted with 3-aminopropyltriethoxysilane, use the eluent to wash away the excessive 3-aminopropyltriethoxysilane. The eluent is composed of n-octane and ethyl acetate (the volume ratio of n-octane to ethyl acetate is 3:1) to obtain the chromatography column;

[0114] S1.5, Purification of Quantum Dots: Add the quantum dot - n - octane solution prepared in step S1.3 to the chromatography column in step S1.4. Then perform chromatography separation using the eluent (the same as the eluent in step S1.4), and use an ultraviolet lamp to confirm the position of the quantum dots in the chromatography column to facilitate the collection of the quantum dot solution flowing out of the chromatography column. Real - time test the photoluminescence quantum yield of the quantum dot solution flowing out of the chromatography column, and collect in segments according to the change of the photoluminescence quantum yield to obtain a purified quantum dot solution.

[0115] In step S1.5, the lower the content of oleic acid ligands on the surface of CdSe quantum dots, the more surface defects, the lower the photoluminescence quantum yield, and the lower the content of oleic acid ligands, the weaker the interaction between CdSe quantum dots and silica gel in the chromatography column, and the earlier the time point of flowing out of the chromatography column. The quantum dot solution is collected in five time periods in total, and the proportion (W, %) of the mass of the quantum dots in the quantum dot solution collected in each time period to the total mass of the quantum dots in the quantum dot - n - octane solution prepared in step S1.3 is detected, and the proportion (M, %) of the molar amount of oleic acid ligands in the quantum dot solution collected in each time period to the total molar amount of the quantum dots is detected, and the average photoluminescence quantum yield (PLQY, %) of the quantum dot solution collected in each time period is detected. The detection results are shown in Table 1 below:

[0116] Table 1

[0117]

[0118]

[0119] Note: For the collection time period, the start time is when the first drop of solution flows out.

[0120] Preserve the quantum dot solution collected in the fifth time period for standby.

[0121] Example 2

[0122] This example provides a method for preparing quantum dots and the prepared quantum dots. The quantum dots are CdSe quantum dots. The emission wavelength of the CdSe quantum dots is 610 nm, the full width at half maximum is 27 nm, the emission color is red, and oleylamine ligands are connected to the surface of the CdSe quantum dots.

[0123] Compared with the method for preparing quantum dots in Example 1, the difference in the method for preparing quantum dots in this example is that step S1.3 is replaced with "At room temperature, 30 mL of ethanol and all the reaction products obtained in step S1.2 are mixed to obtain a mixture, and then the mixture is centrifuged at a speed of 8000 r / min for 3 min. After discarding the supernatant, 5 mL of n-hexane is added to redissolve and disperse the solid, then 5 mL of ethanol is added, and then it is centrifuged at a speed of 8000 r / min for 3 min. After discarding the supernatant, the solid is mixed with 8 mL of 1-octadecene and 1 mL of oleylamine, and then the temperature is raised to 200 °C and reacted for 1 h, and then naturally cooled to room temperature to obtain a reaction product; then, 8 mL of ethanol and all the reaction products are mixed, and then centrifuged at a speed of 8000 r / min for 3 min. After discarding the supernatant, 5 mL of n-hexane is added, and then 5 mL of ethanol is added to precipitate CdSe quantum dots, and then centrifuged at a speed of 8000 r / min for 3 min. After discarding the supernatant, 0.55 mL of n-octane is added and dispersed evenly to obtain a quantum dot-n-octane solution with a concentration of 100 mg / mL, and the average photoluminescence quantum yield of the quantum dots in the quantum dot-n-octane solution is 72%".

[0124] In this example, the lower the content of oleylamine ligands on the surface of CdSe quantum dots, the more surface defects, the lower the photoluminescence quantum yield, and the lower the content of oleylamine ligands, the weaker the interaction between CdSe quantum dots and silica gel in the chromatography column, and the earlier the time point of flowing out from the chromatography column. The quantum dot solution is collected in a total of five time periods, and the W, M, and PLQY of the quantum dot solution collected in each time period are detected with reference to Example 1, and the detection results are shown in Table 2 below:

[0125] Table 2

[0126]

[0127]

[0128] The quantum dot solution collected in the fifth time period is stored for later use.

[0129] Example 3

[0130] This example provides a method for preparing quantum dots and the prepared quantum dots. The quantum dots are CdSe / ZnS quantum dots with a core-shell structure, where the core component is CdSe and the shell component is ZnS. The emission wavelength of the CdSe / ZnS quantum dots is 550 nm, the full width at half maximum is 26 nm, the emission color is green, and oleic acid ligands are connected to the surface of the CdSe / ZnS quantum dots.

[0131] Compared with the method for preparing quantum dots in Example 1, the difference in the method for preparing quantum dots in this example is only that: step S1.2 is replaced with "add 15 mg of selenium powder to the cadmium oleate solution obtained in step S1.1, then introduce argon gas in a bubbling manner for 20 min, stop bubbling and keep the reaction system in an argon atmosphere, then heat the reaction system to 200 °C, react at 200 °C for 1.5 h, and then uniformly drop 2 mL of a mixed solution (composed of 1 mL of zinc oleate-oleic acid solution with a concentration of 0.2 mol / L and 1 mL of sulfur-trioctylphosphine solution with a concentration of 0.25 mol / L) within 20 min, continue to react at 200 °C for 1 h, and naturally cool to room temperature to obtain the reaction product", and the average photoluminescence quantum yield of the quantum dots in the quantum dot-n-octane solution obtained through step S1.3 is 89%.

[0132] In this example, the quantum dot solution was collected in a total of five time periods, and the W, M, and PLQY of the quantum dot solution collected in each time period were detected with reference to Example 1. The detection results are shown in Table 3 below:

[0133] Table 3

[0134]

[0135] The quantum dot solution collected in the fifth time period was stored for later use.

[0136] Example 4

[0137] This example provides an optoelectronic device and a method for preparing the same. The light-emitting device is a quantum dot light-emitting diode with a normal structure. As Figure 2 shown, in the upward direction, the optoelectronic device 1 includes a substrate 10, a first electrode 11, a hole functional layer 15, an active layer 13, an electron functional layer 14, and a second electrode 12 that are sequentially stacked. Among them, the hole functional layer 15 is composed of a hole injection layer 151 and a hole transport layer 152 that are stacked. The hole injection layer 151 is closer to the first electrode 11 than the hole transport layer 152. The first electrode 11 is an anode and the second electrode 12 is a cathode. The materials and thicknesses of each layer in the optoelectronic device 1 are as follows:

[0138] The material of the substrate 10 is glass, and the average thickness of the substrate 10 is 1 mm;

[0139] The material of the first electrode 11 is ITO, and the average thickness of the first electrode 11 is 80 nm;

[0140] The material of the second electrode 12 is Ag, and the average thickness of the second electrode 12 is 80 nm;

[0141] The material of the active layer 13 is the quantum dots in the quantum dot solution collected in the fifth time period in Example 1, and the average thickness of the active layer 13 is 30 nm;

[0142] The material of the electron functional layer 14 is nano-ZnO (average particle size is 5 nm), and the average thickness of the electron functional layer 14 is 40 nm;

[0143] The material of the hole injection layer 151 is PEDOT:PSS, and the average thickness of the hole injection layer 151 is 30 nm;

[0144] The material of the hole transport layer 152 is TFB, and the average thickness of the hole transport layer 152 is 30 nm.

[0145] The preparation method of the optoelectronic device in this embodiment includes the following steps:

[0146] S10.1. Provide a substrate, sputter ITO on one side of the substrate to obtain an ITO layer, wipe the surface of the ITO layer with a cotton swab dipped in a small amount of soapy water to remove visible impurities on the surface, and then ultrasonically clean the substrate including ITO in deionized water for 15 min, ultrasonically clean in acetone for 15 min, ultrasonically clean in ethanol for 15 min, and ultrasonically clean in isopropanol for 15 min. After drying, perform ultraviolet-ozone surface treatment for 15 min to obtain a substrate including a first electrode;

[0147] S10.2. Under the air environment of normal temperature and pressure, spin-coat an aqueous solution of PEDOT:PSS (mass percentage of PEDOT:PSS is 20%) on the side of the first electrode away from the substrate, and then place it in a constant temperature heat treatment at 150 °C to cure into a film to obtain a hole injection layer;

[0148] S10.3. Under the nitrogen environment of normal temperature and pressure, spin-coat a TFB-chlorobenzene solution with a concentration of 8 mg / mL on the side of the hole injection layer away from the anode, and then place it in a constant temperature heat treatment at 150 °C to cure into a film to obtain a hole transport layer;

[0149] S10.4. Under the nitrogen environment of normal temperature and pressure, spin-coat the quantum dot solution collected in the fifth time period in Example 1 on the side of the hole transport layer away from the hole injection layer, and then place it in a constant temperature heat treatment at 80 °C to cure into a film to obtain an active layer;

[0150] S10.5. Under the nitrogen environment of normal temperature and pressure, spin-coat a nano-ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the active layer away from the hole transport layer, and then place it in a constant temperature heat treatment at 80 °C to cure into a film to obtain an electron functional layer;

[0151] S10.6. Place the prefabricated device completed in step S10.5 in a vacuum degree not higher than 3×10 -4In the evaporation chamber of Pa, Ag is thermally evaporated on the side of the electronic functional layer away from the active layer through a mask plate to obtain a second electrode, and then it is encapsulated with epoxy resin glue to obtain an optoelectronic device.

[0152] Example 5

[0153] This example provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Example 4, the difference in the optoelectronic device in this example is that the material of the active layer is the quantum dots in the quantum dot solution collected in the fifth time period in Example 2.

[0154] Compared with the preparation method of the optoelectronic device in Example 4, the difference in the preparation method of the optoelectronic device in this example is that "spin-coating the quantum dot solution collected in the fifth time period in Example 1 on the side of the hole transport layer away from the hole injection layer" in step S10.4 is replaced by "spin-coating the quantum dot solution collected in the fifth time period in Example 2 on the side of the hole transport layer away from the hole injection layer".

[0155] Example 6

[0156] This example provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Example 4, the difference in the optoelectronic device in this example is that the material of the active layer is the quantum dots in the quantum dot solution collected in the fifth time period in Example 3.

[0157] Compared with the preparation method of the optoelectronic device in Example 4, the difference in the preparation method of the optoelectronic device in this example is that "spin-coating the quantum dot solution collected in the fifth time period in Example 1 on the side of the hole transport layer away from the hole injection layer" in step S10.4 is replaced by "spin-coating the quantum dot solution collected in the fifth time period in Example 3 on the side of the hole transport layer away from the hole injection layer".

[0158] Comparative Example 1

[0159] This example provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Example 4, the difference in the optoelectronic device in this comparative example is that the material of the active layer is the quantum dots in the quantum dot - n - octane solution prepared in step S1.3 in Example 1.

[0160] Compared with the preparation method of the optoelectronic device in Example 4, the difference in the preparation method of the optoelectronic device in this comparative example is that "spin-coating the quantum dot solution collected in the fifth time period in Example 1 on the side of the hole transport layer away from the hole injection layer" in step S10.4 is replaced by "spin-coating the quantum dot - n - octane solution with a concentration of 100 mg / mL prepared in step S1.3 in Example 1 on the side of the hole transport layer away from the hole injection layer".

[0161] Comparative Example 2

[0162] This comparative example provides an optoelectronic device and a preparation method thereof. Compared with the optoelectronic device in Example 4, the difference of the optoelectronic device in this comparative example lies in that: the material of the active layer is the quantum dots in the quantum dot - n - octane solution prepared in step S1.3 of Example 2.

[0163] Compared with the preparation method of the optoelectronic device in Example 4, the difference of the preparation method of the optoelectronic device in this comparative example lies in that: replacing "spin - coating the quantum dot solution collected in the fifth time period of Example 1 on the side of the hole - transporting layer away from the hole - injecting layer" in step S10.4 with "spin - coating the quantum dot - n - octane solution with a concentration of 100 mg / mL prepared in step S1.3 of Example 2 on the side of the hole - transporting layer away from the hole - injecting layer".

[0164] Comparative Example 3

[0165] This comparative example provides an optoelectronic device and a preparation method thereof. Compared with the optoelectronic device in Example 4, the difference of the optoelectronic device in this comparative example lies in that: the material of the active layer is the quantum dots in the quantum dot - n - octane solution prepared in step S1.3 of Example 3.

[0166] Compared with the preparation method of the optoelectronic device in Example 4, the difference of the preparation method of the optoelectronic device in this comparative example lies in that: replacing "spin - coating the quantum dot solution collected in the fifth time period of Example 1 on the side of the hole - transporting layer away from the hole - injecting layer" in step S10.4 with "spin - coating the quantum dot - n - octane solution with a concentration of 100 mg / mL prepared in step S1.3 of Example 3 on the side of the hole - transporting layer away from the hole - injecting layer".

[0167] Experimental Example

[0168] Performance detection was carried out on the optoelectronic devices in Examples 4 to 6 and Comparative Examples 1 to 3 respectively. An optoelectronic device efficiency test system was built using a FushiDa FPD optical property measurement device (including Ocean Optics USB2000, LabView - controlled QE - PRO spectrometer, Keithley 2400, high - precision digital source meter Keithley 6485, optical fiber with an inner diameter of 50 μm, device test probes and fixtures, various related connecting wires and data cards, efficiency test dark box and data acquisition system, etc.) to detect parameters such as the turn - on voltage, current, brightness, and emission spectrum of each light - emitting device, and then key parameters such as external quantum efficiency and power efficiency were calculated. The device lifetime of each of the above - mentioned optoelectronic devices was tested using a lifetime test device, and the test environmental temperature was 25 °C and the air humidity was 40%.

[0169] Among them, the test method for current efficiency is: set the emission area to 2 mm × 2 mm = 4 mm 2, intermittently collect the luminance values of the light-emitting device within the range of turn-on voltages from 0 V to 8 V. The initial voltage value for collecting luminance is 3 V, and it is collected every 0.2 V. The luminance value collected each time is divided by the corresponding current density to obtain the current efficiency of the light-emitting device under the collection conditions of that time, and the maximum current efficiency (C.E max , cd / A) is obtained.

[0170] The test method for the device lifetime includes the steps of: under the drive of a constant current (2 mA), use a 128-channel QLED lifetime test system to perform electroluminescence lifetime analysis on each optoelectronic device, record the time (T95, h) required for each optoelectronic device to decay from the maximum luminance to 95%, and calculate through the decay fitting formula to obtain the time (T95@1000nit, h) required for each optoelectronic device to decay from 100% to 95% in luminance at a luminance of 1000 nit.

[0171] The performance detection data of each optoelectronic device are shown in Table 4 below:

[0172] Table 4

[0173]

[0174] As can be seen from Table 4, compared with the optoelectronic device in Comparative Example 1, the T95@1000nit and C.E of the optoelectronic device in Example 4 max are higher; compared with the optoelectronic device in Comparative Example 2, the T95@1000nit and C.E of the optoelectronic device in Example 5 max are higher; compared with the optoelectronic device in Comparative Example 3, the T95@1000nit and C.E of the optoelectronic device in Example 6 max are higher.

[0175] It can be seen from this that separating and purifying the quantum dots prepared by the solution method using the purification method of the embodiments of the present application can improve the performance consistency of the quantum dots prepared by the solution method. Using the quantum dots to prepare the active layer of optoelectronic devices is beneficial to improving the optoelectronic performance and performance stability of optoelectronic devices.

[0176] The above has introduced in detail a composite material, a purification method of quantum dots, and an optoelectronic device provided by the embodiments of the present application. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composite material, characterized in that, The composite material includes a carrier and a first compound, the first compound being connected to the surface of the carrier, and the first compound having a structure represented by the following general formula (I): In general formula (I), R1 and R2 are each independently selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, and a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group; R3 is selected from one or more of a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group, and a substituted or unsubstituted C1-C30 aliphatic alkoxy group; R4 is selected from one or more of a substituted or unsubstituted C1-C30 alkylene group, a substituted or unsubstituted C2-C30 alkenylene group, a substituted or unsubstituted C2-C30 alkynylene group, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C5-C30 heteroarylene group, and an amide group; R5 is selected from an amino group or a carboxyl group.

2. The composite material according to claim 1, characterized in that, The R1 and the R2 are each independently selected from one or more of a C1-C10 aliphatic straight-chain hydrocarbon group, a C3-C10 aliphatic branched-chain hydrocarbon group, and a C3-C10 aliphatic cyclic hydrocarbon group; and / or, the R3 is selected from one or more of a C1-C10 aliphatic straight-chain hydrocarbon group, a C3-C10 aliphatic branched-chain hydrocarbon group, a C3-C10 aliphatic cyclic hydrocarbon group, and a C1-C10 aliphatic alkoxy group; and / or, R4 is selected from one or more of a C1-C10 alkylene group, a C2-C10 alkenylene group, a C2-C10 alkynylene group, a C6-C14 arylene group, a C5-C14 heteroarylene group, and an amide group.

3. The composite material according to claim 1 or 2, characterized in that, The carrier is selected from one or more of silica gel, aluminum oxide, titanium oxide, iron oxide, copper oxide, and zinc oxide; and / or, the carrier is granular, and the mesh number of the carrier is 100 mesh to 300 mesh; and / or, the mass ratio of the carrier to the first compound is 100:(0.5-2); and / or, the first compound is selected from one or more of 3-aminopropyltriethoxysilane, (3-aminopropyl)trimethoxysilane, 3-aminopropyl(diethoxy)methylsilane, and 3-[3-carboxyacrylamido]propyltriethoxysilane.

4. A method for preparing a composite material, characterized in that, It includes the steps of: mixing a carrier and a first compound to obtain the composite material; wherein, the carrier is the carrier as described in any one of claims 1 to 3, and the first compound is the first compound as described in any one of claims 1 to 3.

5. A separator, characterized in that, It includes a stationary phase, and the stationary phase includes the composite material as described in any one of claims 1 to 3, or the composite material prepared by the preparation method of the composite material as described in claim 4.

6. The separator according to claim 5, wherein The separator is columnar; optionally, the separator is a chromatography column.

7. A purification method of quantum dots, characterized in that, It includes the following steps: A separator including a stationary phase is provided, where the stationary phase includes the composite material described in any one of claims 1 to 3, or the composite material prepared by the preparation method of the composite material described in claim 4; A first solution containing quantum dots is provided. At least part of the quantum dots in the first solution have a first ligand connected to their surfaces. The first ligand includes a first group. Pass the first solution through the separator, and the quantum dots with the first ligand connected to their surfaces bind to the carrier through the interaction between the first compound and the first ligand; and A second solution for inducing the quantum dots to detach from the stationary phase is provided. Pass the second solution through the separator so that at least part of the quantum dots bound to the stationary phase flow out of the separator. The lower the content of the first ligand on the surface of the quantum dots, the earlier the time point of flowing out of the separator. Collect the quantum dots in the target outflow time period; One of the first group and R5 of the first compound is an amino group, and the other is a carboxyl group.

8. The purification method of the quantum dots according to claim 7, characterized in that, The general formula of the first ligand is Rs-Rt, where Rt is selected from an amino group or a carboxyl group, and Rs is selected from a substituted or unsubstituted C1-C30 aliphatic straight-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic branched-chain hydrocarbon group, a substituted or unsubstituted C3-C30 aliphatic cyclic hydrocarbon group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C5-C30 heteroaryl group or R7-R6-*, * represents the connection site of Rs and Rt, R7 is selected from an amino group, a carboxyl group, a mercapto group or a hydroxyl group, and R6 is selected from one or more of a substituted or unsubstituted C1-C30 alkylene group, a substituted or unsubstituted C2-C30 alkenylene group, a substituted or unsubstituted C2-C30 alkynylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C5-C30 heteroarylene group; And / or, the step of providing a separator including a stationary phase includes: providing a separator containing the carrier and a third solution including a first compound, adding the third solution to the separator so that the carrier is immersed in the third solution, and then removing the free first compound; And / or, in the first solution, the concentration of the quantum dots is 10 mg / mL to 100 mg / mL; and / or And / or, the second solution includes one or more of a first organic solvent and a second organic solvent. The first organic solvent is selected from one or more of a C6-C18 aliphatic hydrocarbon and a substituted or unsubstituted aromatic hydrocarbon with 6-20 ring atoms; optionally, the C6-C18 aliphatic hydrocarbon is selected from one or more of n-hexane, n-heptane, n-octane, n-nonane, n-decane, 1-hexene, and 1-octene; the general formula of the second organic solvent is R8COOR9, and R8 and R9 are independently selected from C1-C8 chain alkyl groups; And / or, the step of collecting the quantum dots within the target outflow time period includes: obtaining the photoluminescence quantum yield of the quantum dots flowing out from the separator, and collecting the quantum dots flowing out within the corresponding time period according to the target photoluminescence quantum yield.

9. The purification method of the quantum dots according to claim 8, wherein, In the step of adding the third solution to the separator to immerse the carrier in the third solution, the mass ratio of the carrier to the first compound in the third solution is 100:(0.5 - 2); And / or, the separator is columnar, and the carrier is granular; Optionally, the separator is a chromatography column; And / or, the step of removing the free first compound includes: passing a second solution through the separator to allow the free first compound to flow out of the separator; And / or, the first ligand is selected from aliphatic polycarboxylic acid compounds having 3 to 30 carbon atoms or aliphatic polyamine compounds having 3 to 30 carbon atoms; optionally, the aliphatic polycarboxylic acid compounds are selected from one or more of octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, tetracosanoic acid, hexacosanoic acid, oleic acid, linoleic acid, arachidic acid, arachidonic acid, erucic acid, and docosahexaenoic acid, and the aliphatic polyamine compounds are selected from one or more of hexylamine, octylamine, dioctylamine, trioctylamine, nonylamine, decylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, and oleylamine; And / or, the first group is a carboxyl group, and the first compound is selected from one or more of 3-aminopropyltriethoxysilane, (3-aminopropyl)trimethoxysilane, and 3-aminopropyl(diethoxy)methylsilane; or, the first group is an amino group, and the first compound is selected from 3-[3-carboxyacrylamido]propyltriethoxysilane; And / or, the first organic solvent is selected from one or more of toluene, benzene, mesitylene, n-octane, and n-hexane; And / or, the second organic solvent is selected from one or more of ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, and butyl acetate; And / or, the second solution is composed of the first organic solvent and the second organic solvent, and the volume ratio of the first organic solvent to the second organic solvent is 1:(0.1 - 1).

10. A quantum dot, characterized in that, The quantum dots are prepared by the purification method described in any one of claims 7 to 9.

11. The quantum dot according to claim 10, characterized in that, The photoluminescence quantum yield of the quantum dots is not less than 85%, and / or the molar amount of the first ligand located on the surface of the quantum dots is not less than 12% of the total molar amount of the quantum dots; And / or, the quantum dots include one or more of single-structure quantum dots and core-shell structure quantum dots, and the material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, or the shell material of the core-shell structure quantum dots is selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, III-VI group compounds, and I-III-VI group compounds; optionally, the II-VI group compounds are selected from at least one 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, and / or the IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, and / or the III-V group compounds are selected from at least one 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, and / or the III-VI group compounds are selected from one or more of In2S3, In2Se3, InGaS3, and InGaSe3, and / or the I-III-VI group compounds are selected from one or more of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2, AgInGaS2, and CuInGaS2; And / or, the average particle size of the quantum dots is 1 nm to 20 nm.

12. An optoelectronic device includes a first electrode and a second electrode disposed opposite to each other, and a plurality of functional layers disposed between the first electrode and the second electrode, wherein, The material of at least one functional layer among the multiple functional layers includes quantum dots prepared by the purification method as described in any one of claims 7 to 9, or quantum dots as described in claims 10 or 11.

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