Nano material, preparation method thereof and photoelectric device

Abstract

The invention discloses a nano material, a preparation method thereof and a photoelectric device, and relates to the technical field of photoelectricity. The nano material comprises a quantum dot and a first ligand, the structural formula of the first ligand is R-X, the first ligand is connected to the surface of the quantum dot through an X group, and the X group comprises one or more of-COOD,-SD,-OD and-ND2. According to the nano material provided by the invention, the X group containing the deuterium element is firmly adsorbed on the surface of the quantum dot, so that the stability of the quantum dot can be improved.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technologies, and particularly to a nanomaterial, a preparation method thereof, and an optoelectronic device. Background Art

[0002] Currently, the widely used optoelectronic devices are organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs). Due to its excellent display performance such as self-luminescence, simple structure, ultra-thin and light, fast response speed, wide viewing angle, low power consumption, and flexible display, OLED has become the mainstream technology in the display technology field. QLED has the advantages of saturated emission light color and adjustable wavelength, and high photoluminescence and electroluminescence quantum yields, and has become a strong competitor of OLED in recent years.

[0003] However, currently, the stability of quantum dots is relatively low and needs to be further improved. Summary of the Invention

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

[0005] An embodiment of this application is implemented as follows. A nanomaterial includes quantum dots and a first ligand. The structural formula of the first ligand is: R-X, and the first ligand is connected to the surface of the quantum dots through the X group;

[0006] Wherein, the X group includes one or more of -COOD, -SD, -OD, -ND2;

[0007] The R includes one or more of hydrogen, a substituted or unsubstituted C1-C24 alkyl group, a substituted or unsubstituted C2-C24 alkenyl group, a substituted or unsubstituted C2-C24 alkynyl group, a substituted or unsubstituted C1-C24 alkoxy group, a substituted or unsubstituted C1-C24 acyloxy group, a substituted or unsubstituted C1-C24 alkoxycarbonyl group, a substituted or unsubstituted C6-C24 aryl group, a substituted or unsubstituted C3-C24 heterocyclic group;

[0008] The substituents of the substituted groups each independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN.

[0009] Correspondingly, an embodiment of this application also provides a preparation method of a nanomaterial, including:

[0010] Providing a quantum dot precursor, the quantum dot precursor includes a metal source and an anion source, or includes quantum dots and a second ligand connected to the surface of the quantum dots;

[0011] A solvent and a first ligand are provided. The structural formula of the first ligand is: R-X, where the X group includes one or more of -COOD, -SD, -OD, -ND2, and the R includes one or more of hydrogen, substituted or unsubstituted C1-C24 alkyl, substituted or unsubstituted C2-C24 alkenyl, substituted or unsubstituted C2-C24 alkynyl, substituted or unsubstituted C1-C24 alkoxy, substituted or unsubstituted C1-C24 acyloxy, substituted or unsubstituted C1-C24 alkoxycarbonyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heterocyclic group; the substituents of the substitution independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN; the solvent and the first ligand are mixed with the quantum dot precursor to obtain a nanomaterial.

[0012] Correspondingly, an embodiment of the present application further provides an optoelectronic device, including a first electrode, a light-emitting layer, and a second electrode stacked in sequence. The light-emitting layer includes the above-mentioned nanomaterial or the nanomaterial prepared by the above-mentioned preparation method.

[0013] For the nanomaterial provided by the present application, the X group containing deuterium element is firmly adsorbed on the surface of the quantum dot, which can improve the stability of the quantum dot. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0015] Figure 1 It is a flowchart of the preparation method of the nanomaterial provided by the embodiment of the present application;

[0016] Figure 2 It is a schematic structural diagram of the optoelectronic device provided by the embodiment of the present application;

[0017] Figure 3 It is a schematic structural diagram of another optoelectronic device provided by the embodiment of the present application.

[0018] Reference Signs:

[0019] First electrode 10; Light-emitting layer 20; Second electrode 30; First carrier functional layer 40; Second carrier functional layer 50. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying 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. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0021] In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" usually refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of the present application, the term "including" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish an order.

[0022] In the present application, "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B may be singular or plural.

[0023] In the present application, "at least one" means one or more, and "a plurality" means two or more. "One or several", "at least one (item) below" or similar expressions refer to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can all represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0024] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the described range description has specifically disclosed all possible sub - ranges and the single 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 the single numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. In addition, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0025] The light-emitting layer material of QLED is quantum dots. For quantum dots, the performance changes are mainly determined by three conditions: the environment it is in, the influence of its own structural changes, and the shedding of surface ligands. Among them, the environment of quantum dots is mainly controlled by device structure, storage environment, etc.; the structural changes are determined by the process during synthesis; and the surface ligands are determined by ligand type, surface state, etc.

[0026] Quantum dot surface ligands include: the adsorbed type adsorbed on the surface of QD and the coordinated type coordinated on the surface defects of QD. In these two ways, the adsorbed type mainly acts by van der Waals forces, enabling the surface to couple with each other between dipole moments to generate electrostatic adsorption, thus adhering to the surface of QD.

[0027] The coordinated type is mainly connected by the force between ionic bonds. To enhance the stability of coordinated quantum dots, mainly from increasing the coordination methods of the coordinated type, such as changing ligands, changing the QD synthesis method to enhance its coordination ability, etc. To enhance the stability of adsorbed quantum dots, ligands with strong adsorption ability can be used for adsorption. In the current synthesis process of quantum dots, the main indicators of quantum dots are stability and optoelectronic properties, and neither can be lacking. And for some synthesis schemes with good optoelectronic properties, due to structural reasons, the surface ligands are prone to shedding, resulting in poor performance, that is, the stability of this scheme is not good enough; at this time, the QD structure is often modified to increase its stability, but this will sacrifice part of the optoelectronic properties.

[0028] The technical solution of this application is as follows:

[0029] In the first aspect, the embodiments of this application provide a nanomaterial, the nanomaterial includes quantum dots and a first ligand, and the structural formula of the first ligand is: R-X, and the first ligand is connected to the surface of the quantum dots through the X group;

[0030] Among them, the X group includes one or more of -COOD, -SD, -OD, -ND2;

[0031] The R includes one or more of hydrogen, substituted or unsubstituted C1-C24 alkyl, substituted or unsubstituted C2-C24 alkenyl, substituted or unsubstituted C2-C24 alkynyl, substituted or unsubstituted C1-C24 alkoxy, substituted or unsubstituted C1-C24 acyloxy, substituted or unsubstituted C1-C24 alkoxycarbonyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heterocyclic group;

[0032] The substituents of the substitution each independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN.

[0033] It should be noted that D represents the deuterium element.

[0034] In the nanomaterial provided by this application, the first ligand of the quantum dots contains deuterium elements. Since the movement speed of deuterium is relatively low, the first ligand has stronger inertness. Since deuterium consists of one proton, one neutron and one electron, the intermolecular force is relatively large, and both the van der Waals force and the intermolecular force increase, which significantly enhances the adsorption capacity of the first ligand, firmly adsorbing on the surface of the quantum dots and significantly improving the stability of the quantum dots.

[0035] In some embodiments, the first ligand includes an adsorption ligand.

[0036] In some embodiments, R includes one or more of hydrogen, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 acyloxy, substituted or unsubstituted C1-C20 alkoxycarbonyl, substituted or unsubstituted C6-C20 aryl, and substituted or unsubstituted C3-C20 heterocyclic group.

[0037] Optionally, the C1-C20 alkyl includes one or more of methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, heptadecyl.

[0038] Optionally, the C2-C20 alkenyl includes one or more of vinyl, propenyl, butenyl, hexenyl, octenyl, decenyl, dodecenyl, 9-heptadecenyl, 1,4-pentadienyl, 1,5-hexadienyl, 1,6-heptadienyl, 1,7-octadienyl, 1,8-nonadienyl, 1,9-decadienyl.

[0039] Optionally, the C2-C20 alkynyl includes one or more of ethynyl, propynyl, pentynyl, heptynyl, hexynyl, octynyl, decynyl, dodecynyl.

[0040] Optionally, the C1-C20 alkoxy includes one or more of methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, hexyloxy, octyloxy, decyloxy, dodecyloxy; optionally, the C1-C20 acyloxy includes one or more of formyloxy, acetyloxy, propionyloxy, butyryloxy, pivaloyloxy, heptanoyloxy, hexanoyloxy, octanoyloxy, decanoyloxy, dodecanoyloxy, octanoyloxy, palmitoyloxy, stearoyloxy.

[0041] Optionally, the C1-C20 alkoxycarbonyl group includes one or more of methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl, hexyloxycarbonyl, decyloxycarbonyl, dodecyloxycarbonyl, octyloxycarbonyl, palmityloxycarbonyl, stearyloxycarbonyl.

[0042] Optionally, the C6-C20 aryl group includes one or more of phenyl, p-tolyl, p-nitrophenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, 4-nitro-2-methoxyphenyl.

[0043] Optionally, the heteroatoms in the C3-C20 heterocyclic group include one or more of O, P, N, S.

[0044] Optionally, the C3-C20 heterocyclic group includes one or more of thiazolyl, thienyl, furyl, pyrrolyl, pyridyl, pyrimidinyl, imidazolyl, oxazolyl, pyrazinyl, indolyl, quinolinyl, pteridinyl, acridinyl.

[0045] In some embodiments, the first ligand includes one or more of CH3(CH2)7CH=CH(CH2)7COOD, DSCH2COOD, DS(CH2)2COOD, CH3(CH2)2SD, DS(CH2)2SD, CH3(CH2)3SD, CH3(CH2)7SD, CH3(CH2) 11 SD, CH3(CH2) 17 SD, C6H5SD, C6H4SDSD, CH3(CH2)7CH=CH(CH2)7ND2. It should be noted that the first ligands are obtained by replacing H in some groups of conventional compounds with D and can be purchased from chemical material companies.

[0046] In some embodiments, in the nanomaterial, the mass fraction of the first ligand is 0.5% to 2%, for example, it can be 0.8%, 1%, 1.2%, 1.5%, 1.8%, etc. Within this mass fraction range, it is beneficial for the first ligand to improve the performance of the nanomaterial.

[0047] In some embodiments, the average particle size of the quantum dots is 5 nm to 15 nm, for example, it can be 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, etc.

[0048] In some embodiments, the quantum dots can be selected from, but not limited to, one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite-type semiconductor materials.

[0049] The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots can be respectively selected from, but not limited to, the single-structure quantum dots selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds can be selected from, but not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds can be selected from, but not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds can be selected from, but not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds can be selected from, but not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0050] As an example, the quantum dots of the core-shell structure 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. In the expressions such as CdSe / ZnS above, " / " means that the material after " / " (as the shell layer) coats the material before " / " (as the core layer).

[0051] The perovskite semiconductor material can be selected from, but not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMY3, where A is Cs + ion, M is a divalent metal cation, selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of them. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMY3, where B is an organic amine cation, selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation, selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of them, and Y is a halogen anion, selected from Cl - , Br - , I - and one or more of them.

[0052] In some embodiments, the nanomaterial further includes a second ligand attached to the surface of the quantum dots.

[0053] In some embodiments, the second ligand includes one or more of oleic acid, mercaptoacetic acid, mercaptopropionic acid, 1,2-ethanedithiol, propanethiol, butanethiol, octanethiol, dodecanethiol, octadecanethiol, benzenethiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, and oleylamine.

[0054] In some embodiments of the nanomaterial, the molar ratio of the first ligand to the second ligand is [80, 100):(0, 20], and can be, for example, 82:18, 85:15, 88:12, 90:10, 92:8, 95:5, 98:2, etc.

[0055] It should be noted that the symbol (a, b) represents all real numbers between the real numbers a and b, but does not include a and b, which is equivalent to the set of numbers {x|a < x < b}, denoted as (a, b), and the values do not include a and b. The symbol [a, b] represents all real numbers between the real numbers a and b, including a and b. It is equivalent to the set of numbers {x|a ≤ x ≤ b}, denoted as [a, b], and the values include a and b. Correspondingly, [80, 100) represents the set of numbers {x|80 ≤ x < 100}, including 80 but not including 100, and (0, 20] represents the set of numbers {x|0 < x ≤ 20}, not including 0 but including 20.

[0056] In a second aspect, please refer to Figure 1 , embodiments of the present application provide a method for preparing a nanomaterial, including:

[0057] S11. Provide a quantum dot precursor, where the quantum dot precursor includes a metal source and an anion source, or includes quantum dots and a second ligand attached to the surface of the quantum dots;

[0058] S12. Provide a solvent and a first ligand. The structural formula of the first ligand is: R-X, where the X group includes one or more of -COOD, -SD, -OD, -ND2, and the R includes one or more of hydrogen, substituted or unsubstituted C1-C24 alkyl, substituted or unsubstituted C2-C24 alkenyl, substituted or unsubstituted C2-C24 alkynyl, substituted or unsubstituted C1-C24 alkoxy, substituted or unsubstituted C1-C24 acyloxy, substituted or unsubstituted C1-C24 alkoxycarbonyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heterocyclic group; the substituents of the substitution each independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN; mix the solvent and the first ligand with the quantum dot precursor to obtain a nanomaterial.

[0059] In some embodiments, the quantum dot precursor includes a metal source and an anion source, and the solvent includes a first solvent; mix the metal source, the anion source with the first solvent and the first ligand to synthesize quantum dots and obtain a nanomaterial.

[0060] In the preparation method of the above nanomaterial, during the synthesis of quantum dots, a first ligand containing deuterium element is used to participate in the synthesis of quantum dots. Deuterium has no adverse effect on the structure of quantum dots, and the reaction conditions do not need to be specifically changed during the synthesis process of quantum dots, which is very convenient. In addition, due to the introduction of deuterium element, the adsorption ligands on the surface of quantum dots increase. After multiple washings, the ligands at the defect sites are still difficult to fall off and are tightly and firmly bound to the quantum dots, improving the stability of the nanomaterial.

[0061] It should be noted that the synthesis of quantum dots can adopt conventional methods in the art, such as organic phase synthesis method, aqueous phase synthesis method, hydrothermal method, solvothermal method, microwave-assisted hydrothermal method, microemulsion method, physical vapor deposition method, chemical vapor deposition method, sol-gel method, precipitation method, epitaxial growth method, electric field confinement method, etc.

[0062] Exemplarily, in some embodiments, the metal source includes a first metal source, and the first metal source includes one or more of cadmium source, zinc source, mercury source, tin source, lead source, gallium source, antimony source, aluminum source, indium source, copper source. For example, the first metal source can be one or more of cadmium oxide, dimethyl cadmium, diethyl cadmium, zinc acetate or zinc chloride, dimethyl zinc, diethyl zinc.

[0063] The anion source includes a first anion source, and the first anion source includes one or more of a sulfur source, a selenium source, a tellurium source, a nitrogen source, an arsenic source, and a phosphorus source. For example, the first anion source can be one or more of carbon diselenide, trioctylphosphine selenide (Se-TOP), tributylphosphine selenide, sulfur powder, thiourea, and sodium sulfide.

[0064] In some embodiments, the temperature for synthesizing the quantum dots is 280 °C to 350 °C, and for example, it can be 290 °C, 300 °C, 310 °C, 320 °C, 330 °C, 340 °C, etc.

[0065] In some embodiments, the metal source further includes a second metal source, and the second metal source includes one or more of a cadmium source, a zinc source, a mercury source, a tin source, a lead source, a gallium source, an antimony source, an aluminum source, an indium source, and a copper source. For example, the first metal source can be one or more of cadmium oxide, dimethylcadmium, diethylcadmium, zinc acetate or zinc chloride, dimethylzinc, and diethylzinc.

[0066] The anion source further includes a second anion source, and the second anion source includes one or more of a sulfur source, a selenium source, a tellurium source, a nitrogen source, an arsenic source, and a phosphorus source. For example, the first anion source can be one or more of carbon diselenide, trioctylphosphine selenide (Se-TOP), tributylphosphine selenide, sulfur powder, thiourea, and sodium sulfide.

[0067] It can be understood that the second metal source and the second anion source are used to synthesize the shell layer of the core-shell structure quantum dots.

[0068] In some embodiments, the first solvent includes one or more of octadecene, paraffin oil, and stearic acid.

[0069] In some other embodiments, the quantum dot precursor includes a quantum dot and a second ligand attached to the surface of the quantum dot, and the solvent includes a second solvent; the quantum dot and the second ligand attached to the surface of the quantum dot are mixed with the second solvent and the first ligand for ligand exchange to obtain a nanomaterial.

[0070] In some embodiments, the second ligand is one or more of oleic acid, mercaptoacetic acid, mercaptopropionic acid, 1,2-ethanedithiol, propanethiol, butanethiol, octanethiol, dodecanethiol, octadecanethiol, benzenethiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, and oleylamine.

[0071] In the preparation method of the above-mentioned nanomaterial, after the quantum dots have been synthesized, ligand exchange is performed on the ligands of the quantum dots using a first ligand containing deuterium elements. The intermolecular force of the first ligand is stronger than that of the second ligand, so that the first ligand has a competitive advantage, and the replacement is completed through the principle of strong force replacing weak force, so that the first ligand is attached to the quantum dots.

[0072] It should be noted that due to objective reasons, it may be difficult to completely replace the first ligand. Therefore, in some embodiments, the surface of the quantum dots in the nanomaterial includes both the first ligand and some of the second ligands that have not been replaced.

[0073] In some embodiments, the second solvent includes one or more of toluene, n-hexane, chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, N,N-dimethylformamide, ethyl acetate, pyrrole, butyric acid, and cresol.

[0074] In some embodiments, the temperature for ligand replacement is 20°C to 75°C, for example, it can be 25°C, 35°C, 45°C, 55°C, 65°C, etc. Within this temperature range, it is beneficial for the second ligand to fall off, enabling the first ligand to be replaced.

[0075] It can be understood that the adsorption capacity of oleic acid to quantum dots is not strong, and ligand replacement can occur under heating conditions. The adsorption capacity of thiol to quantum dots is relatively strong, and ligand replacement can be achieved through ultrasonic oscillation. Further, the frequency of the ultrasonic wave is 2 kHz to 20 kHz, for example, it can be 5 kHz, 8 kHz, 10 kHz, 12 kHz, 15 kHz, 18 kHz, etc.

[0076] In a third aspect, please refer to Figure 2 , an optoelectronic device is further provided in an embodiment of the present application, including a first electrode 10, a light-emitting layer 20, and a second electrode 30 stacked in sequence, and the light-emitting layer includes the above-mentioned nanomaterial.

[0077] In some embodiments, the optoelectronic device includes a light-emitting diode.

[0078] In some embodiments, the optoelectronic device is a normal-type optoelectronic device.

[0079] In other embodiments, the optoelectronic device is an inverted-type optoelectronic device.

[0080] In some embodiments, please refer to Figure 3 , the optoelectronic device further includes one or more of a first carrier functional layer 40 and a second carrier functional layer 50. The first carrier functional layer 40 is disposed between the first electrode 10 and the light-emitting layer 20, and the second carrier functional layer 50 is disposed between the light-emitting layer 20 and the second electrode 30.

[0081] In some embodiments, the first charge carrier functional layer 40 is a hole functional layer, and the second charge carrier functional layer 50 is an electron functional layer. Correspondingly, the first electrode 10 is an anode, and the second electrode 30 is a cathode.

[0082] In other embodiments, the second charge carrier functional layer 50 is a hole functional layer, and the first charge carrier functional layer 40 is an electron functional layer. Correspondingly, the second electrode 30 is an anode, and the first electrode 10 is a cathode.

[0083] Furthermore, the hole functional layer includes one or more of a hole injection layer and a hole transport layer.

[0084] The electron functional layer includes one or more of an electron injection layer and an electron transport layer.

[0085] In some embodiments, the first electrode 10 and the second electrode 30 each independently include one or several of a metal, a carbon material, and a metal oxide; the metal includes one or several of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes one or several of graphite, a carbon nanotube, graphene, and carbon fiber; the metal oxide includes a metal oxide electrode or a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides. The material of the metal oxide electrode includes one or several of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO, and the composite electrode includes one or several of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. Herein, " / " represents a stacked structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer, and an AZO layer stacked in sequence.

[0086] In some embodiments, the materials of the hole functional layer include 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent material, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-bis(naphthalen-1-yl)-N,N'-diphenylbenzidine, spiro-NPB, nanocrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, wherein the metal oxides in the second doped metal oxide particles and the metal oxides in the second undoped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping elements in the second doped metal oxide particles include one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfides include one or more of CuS, MoS3, WS3, the metal selenides include one or more of MoSe3, WSe3, and the metal nitrides include p-type gallium nitride.

[0087] In some embodiments, the material of the electronic functional layer includes one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxides in the first doped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, and CdS. The IIIA-VA group semiconductor materials include one or more of InP and GaP. The IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS.

[0088] In a sixth aspect, an embodiment of the present application further provides a display device, and the display device includes the above-mentioned optoelectronic device.

[0089] The display device can be any electronic product with a display function. The electronic products include but are not limited to smartphones, tablet computers, laptop computers, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, in-vehicle displays, televisions, or e-book readers. Among them, the smart wearable devices can be, for example, smart bracelets, smart watches, virtual reality (VR) helmets, etc.

[0090] The present application will be specifically described below through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application.

[0091] Embodiment 1

[0092] This embodiment provides a nanomaterial, which includes CdSe quantum dots and a first ligand CH3(CH2)7CH=CH(CH2)7COOD connected to the surface of the CdSe quantum dots. The preparation method of the nanomaterial includes:

[0093] Providing cadmium oxide and octadecene, mixing them with the first ligand, the concentration of cadmium oxide is 5 mmol / mL, and the molar ratio of the first ligand to octadecene is 2:1; heating to 300 °C and injecting trioctylphosphine selenide, reacting to obtain CdSe quantum dots with the first ligand CH3(CH2)7CH=CH(CH2)7COOD connected to the surface.

[0094] Example 2

[0095] This example is basically the same as Example 1, except that in this example, trioctylphosphine selenide is replaced by sodium sulfide to obtain CdSe quantum dots with the first ligand CH3(CH2)7CH=CH(CH2)7COOD connected to the surface.

[0096] Example 3

[0097] This example is basically the same as Example 1, except that in this example, zinc acetate and sodium sulfide are injected on the basis of Example 1 to form a ZnS shell, and core-shell quantum dots CdSe / ZnS with the first ligand CH3(CH2)7CH=CH(CH2)7COOD connected to the surface are obtained.

[0098] Example 4

[0099] Take 0.4 g of Cs2CO3, 1.5 mL of the first ligand CH3(CH2)7CH=CH(CH2)7COOD, and 20 mL of octadecene and mix them in a three-necked flask. After introducing nitrogen to form an inert gas atmosphere, heat to 120 °C and continuously stir for 1 h, and then raise the temperature to 160 °C and continue stirring for 20 min to obtain a precursor solution. Mix the dried Br-type anion exchange resin with the precursor solution in a ratio of 1 g / 20 ml and continuously stir at 500 r / min for 2 h to obtain perovskite quantum dots CsPbBr3 with the first ligand CH3(CH2)7CH=CH(CH2)7COOD connected to the surface.

[0100] Example 5

[0101] This example is basically the same as Example 1, except that in this example, the first ligand is CH3(CH2)2SD.

[0102] Example 6

[0103] This example is basically the same as Example 1, except that in this example, the synthesis temperature of the quantum dots is 350 °C.

[0104] Example 7

[0105] This example is basically the same as Example 1, except that in this example, the synthesis temperature of the quantum dots is 280 °C.

[0106] Example 8

[0107] CdSe quantum dots and oleic acid ligands attached to the surface of the CdSe quantum dots are provided, dissolved in a n - hexane reagent. The first ligand in Example 1 is added, heated to 70 °C until clarified and then immediately cooled. After purification, CdSe quantum dots with the first ligand CH3(CH2)7CH=CH(CH2)7COOD attached to the surface are obtained.

[0108] Example 9

[0109] This example is basically the same as Example 8, except that in this example, the CdSe quantum dots are replaced with CdS quantum dots.

[0110] Example 10

[0111] This example is basically the same as Example 8, except that in this example, the CdSe quantum dots are replaced with CdSe / ZnS quantum dots.

[0112] Example 11

[0113] This example is basically the same as Example 8, except that in this example, the CdSe quantum dots are replaced with perovskite quantum dots CsPbBr3.

[0114] Example 12

[0115] This example is basically the same as Example 8, except that in this example, the first ligand in Example 1 is replaced with the first ligand in Example 5, and the ligand replacement process also includes ultrasonic treatment at a frequency of 10 kHz.

[0116] Example 13

[0117] This example is basically the same as Example 8, except that in this example, the ligand replacement temperature is 75 °C.

[0118] Example 14

[0119] This example is basically the same as Example 8, except that in this example, the ligand replacement temperature is 20 °C.

[0120] Comparative Example 1

[0121] This example provides a nanomaterial, including CdSe quantum dots and ligands attached to the surface of the CdSe quantum dots. Its preparation method includes:

[0122] Provide a mixture of cadmium oxide, oleic acid and octadecene, with the concentration of cadmium oxide being 5 mmol / mL and the molar ratio of oleic acid to octadecene being 2:1; heat up to 300 °C and inject trioctylphosphine selenide, react to obtain CdSe quantum dots with oleic acid ligands attached to the surface.

[0123] Comparative Example 2

[0124] This comparative example is basically the same as Comparative Example 1, except that in this comparative example, oleic acid is replaced by propanethiol.

[0125] Device Example 1

[0126] This device example provides an optoelectronic device, and the preparation method is as follows:

[0127] Provide ITO glass, dip a cotton swab in a small amount of soapy water and wipe the ITO surface to remove visible impurities on the surface. Then, ultrasonically clean it with deionized water, acetone, ethanol, and isopropanol for 15 min, and then dry it with nitrogen and irradiate it with UV for 15 min to form an ITO anode;

[0128] Spin-coat PEDOT:PSS on the ITO anode at a rotation speed of 5000 rpm for 30 s, and then heat it at 100 °C for 15 min to form a hole injection layer;

[0129] Dissolve TFB in chlorobenzene at a concentration of 8 mg / mL, spin-coat it on the hole injection layer at a rotation speed of 3000 rpm for 30 s, and then heat it at 100 °C for 15 min to form a hole transport layer;

[0130] Dissolve the nanomaterial of Example 1 in a n-hexane solution to prepare a quantum dot solution with a concentration of 30 mg / mL, and set the quantum dot solution on the hole transport layer to obtain a light-emitting layer;

[0131] Spin-coat an ethanol solution of ZnO on the light-emitting layer at a rotation speed of 4000 rpm, and then heat it at 80 °C for 10 min to form an electron transport layer;

[0132] On the electron transport layer, turn on the Ag target, and the Ag target is evaporated at a rate of to form a cathode;

[0133] Encapsulate to obtain an optoelectronic device.

[0134] Device Examples 2 to 14

[0135] Device Examples 2 to 14 are basically the same as Device Example 1, except that the nanomaterials of Example 1 are respectively replaced by the nanomaterials of Examples 2 to 14 to form a light-emitting layer, and an optoelectronic device is obtained.

[0136] Device Comparative Examples 1 to 2

[0137] Device Comparative Examples 1 to 2 are basically the same as Device Example 1, except that the nanomaterials of Example 1 are respectively replaced by the nanomaterials of Comparative Examples 1 to 2 to form a light-emitting layer, and an optoelectronic device is obtained.

[0138] The external quantum efficiency EQE (%) and the lifetime T95@1k nit of the optoelectronic devices of Device Examples 1 to 14 and Device Comparative Examples 1 to 2 were tested, and the test results are shown in Table 1.

[0139] Among them, the test method for the external quantum efficiency EQE is as follows: the ratio of the number of electron-hole pairs injected into the quantum dots to the number of emitted photons, with the unit of %, is an important parameter for measuring the quality of electroluminescent devices, and it can be obtained by measuring with an EQE optical test instrument. The specific calculation formula is as follows:

[0140]

[0141] Among them, ηe is the optical output coupling efficiency, ηr is the ratio of the number of recombined carriers to the number of injected carriers, χ is the ratio of the number of excitons generating photons to the total number of excitons, K R is the radiation process rate, and K NR is the non-radiation process rate. Test conditions: carried out at room temperature, and the air humidity is 30 - 60%.

[0142] The test method for the lifetime T95@1000nit is as follows: the time required for the device to reduce the brightness to a certain proportion of the maximum brightness under the drive of a constant current or voltage. The time when the brightness drops to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the test cycle, the device lifetime test is usually carried out by accelerating the device aging at high brightness, and the lifetime at high brightness is obtained by fitting with the extended exponential decay brightness decay fitting formula. For example, the lifetime at 1000nit is denoted as T95@1k nit. The specific calculation formula is as follows:

[0143]

[0144] Among them, T95L is the lifetime at low brightness, T95 H is the measured lifetime at high brightness, L H is the device accelerated to the maximum brightness, L L is 1000nit, A is the acceleration factor, and in this experiment, the A value is obtained as 1.7 by measuring the lifetimes of several groups of red QLED devices at the rated brightness.

[0145] Table 1

[0146]

[0147]

[0148] As can be seen from Table 1:

[0149] It can be seen from Device Examples 1-7 and Device Comparative Examples 1-2 that in the process of synthesizing quantum dots in this application, the first ligand containing deuterium element is used. Deuterium has little influence on the structure of quantum dots themselves. Without deliberately changing the reaction conditions, the external quantum efficiency and service life of optoelectronic devices can be effectively improved; the performance of core-shell structure quantum dots is better than that of single-structure quantum dots, and the performance of single-structure quantum dots is better than that of perovskite quantum dots; within the range of the quantum dot synthesis temperature provided in this application by replacing the material of single-structure quantum dots, the performance differences between optoelectronic devices are not significant, and the performance of optoelectronic devices has been effectively improved compared with that of Device Comparative Example 1 using oleic acid ligand without deuterium element.

[0150] It can be seen from Device Examples 1, 8 and Device Comparative Example 1 that whether the first ligand containing deuterium element is used for quantum dot synthesis during the preparation of quantum dots or the first ligand containing deuterium element is replaced on the basis of the already synthesized quantum dots, the firmness of the connection between the first ligand containing deuterium element and the quantum dots can be effectively improved, thereby improving the stability of the quantum dots, further improving the external quantum efficiency of optoelectronic devices, and prolonging the service life of optoelectronic devices; among them, the effect of Device Example 1 using the first ligand containing deuterium element during the synthesis process is slightly better than that of Device Example 8 with ligand replacement.

[0151] It can be seen from Device Examples 8-14 and Device Comparative Examples 1-2 that by replacing the first ligand containing deuterium element on the basis of quantum dot synthesis, the first ligand containing deuterium element can also be effectively connected to the quantum dots. The performance of the optoelectronic devices in Device Examples 8-14 is better than that in Device Comparative Examples 1-2. After the quantum dots are connected to the first ligand containing deuterium element, the performance is more stable, thereby improving the external quantum efficiency of optoelectronic devices and prolonging the service life of optoelectronic devices.

[0152] The above has introduced in detail the nanomaterials, their preparation methods, and optoelectronic devices provided in the embodiments of this application. Specific examples are used in this article to elaborate on the principles and implementation methods of this application. The descriptions of the above embodiments are only used to help understand the method and its core idea of this application; at the same time, for those skilled in the art, based on the idea of this application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A nanomaterial, characterized in that, The nanomaterial includes quantum dots and a first ligand. The structural formula of the first ligand is: R-X, and the first ligand is connected to the surface of the quantum dots through the X group; Wherein, the X group includes one or more of -COOD, -SD, -OD, -ND2; The R includes one or more of hydrogen, substituted or unsubstituted C1-C24 alkyl, substituted or unsubstituted C2-C24 alkenyl, substituted or unsubstituted C2-C24 alkynyl, substituted or unsubstituted C1-C24 alkoxy, substituted or unsubstituted C1-C24 acyloxy, substituted or unsubstituted C1-C24 alkoxycarbonyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heterocyclic group; The substituents of the substitution each independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN.

2. The nanomaterial according to claim 1, characterized in that, The R includes one or more of hydrogen, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 acyloxy, substituted or unsubstituted C1-C20 alkoxycarbonyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C3-C20 heterocyclic group; Optionally, the C1-C20 alkyl includes one or more of methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, heptadecyl; Optionally, the C2-C20 alkenyl includes one or more of vinyl, propenyl, butenyl, hexenyl, octenyl, decenyl, dodecenyl, 9-heptadecenyl, 1,4-pentadienyl, 1,5-hexadienyl, 1,6-heptadienyl, 1,7-octadienyl, 1,8-nonadienyl, 1,9-decadiene; Optionally, the C2-C20 alkynyl includes one or more of ethynyl, propynyl, pentynyl, heptynyl, hexynyl, octynyl, decynyl, dodecynyl; optionally, the C1-C20 alkoxy includes one or more of methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, hexyloxy, octyloxy, decyloxy, dodecyloxy; Optionally, the C1-C20 acyloxy includes one or more of formyloxy, acetyloxy, propionyloxy, butyryloxy, pentyryloxy, heptyryloxy, hexyryloxy, octyryloxy, decyryloxy, dodecyryloxy, octyryloxy, palmitoyloxy, stearoyloxy; Optionally, the C1-C20 alkoxycarbonyl includes one or more of methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl, hexyloxycarbonyl, decyloxycarbonyl, dodecyloxycarbonyl, octyloxycarbonyl, palmitoxycarbonyl, stearoxycarbonyl; Optionally, the C6-C20 aryl group includes one or more of phenyl, p-tolyl, p-nitrophenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, 4-nitro-2-methoxyphenyl; Optionally, the heteroatoms in the C3-C20 heterocyclic group include one or more of O, P, N, S; Optionally, the C3-C20 heterocyclic group includes one or more of thiazolyl, thiophenyl, furyl, pyrrolyl, pyridyl, pyrimidinyl, imidazolyl, oxazolyl, pyrazinyl, indolyl, quinolinyl, pteridinyl, acridinyl; 3. The nanomaterial according to claim 1, characterized in that, The first ligand includes one or more of CH3(CH2)7CH=CH(CH2)7COOD, DSCH2COOD, DS(CH2)2COOD, CH3(CH2)2SD, DS(CH2)2SD, CH3(CH2)3SD, CH3(CH2)7SD, CH3(CH2) 11 SD, CH3(CH2) 17 SD, C6H5SD, C6H4SDSD, CH3(CH2)7CH=CH(CH2)7ND2; and / or In the nanomaterial, the mass fraction of the first ligand is 0.5% - 2%; and / or The quantum dots include one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials. 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 each independently selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2. The perovskite semiconductor materials include doped or undoped inorganic perovskite semiconductor materials and organic-inorganic hybrid perovskite semiconductor materials. The structural general formula of the inorganic perovskite semiconductor material is AMY3, where A is a Cs + ion, M is a divalent metal cation selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ 、Cd 2+ 、Cr 2+ 、Mn 2 + 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ One or more of; the structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMY3, where B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ 、Sn 2+ 、Cu 2+ 、Ni 2+ 、Cd 2+ 、Cr 2+ 、Mn 2+ 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ One or more of, and Y is a halogen anion selected from Cl - 、Br - 、I - One or more of; and / or The average particle size of the quantum dots is 5 nm - 15 nm.

4. The nanomaterial according to claim 1, characterized in that, The nanomaterial further includes a second ligand connected to the surface of the quantum dots; Optionally, the second ligand includes one or more of oleic acid, mercaptoacetic acid, mercaptopropionic acid, 1,2-ethanedithiol, propanethiol, butanethiol, octanethiol, dodecanethiol, octadecanethiol, benzenethiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, oleylamine; Optionally, in the nanomaterial, the molar ratio of the first ligand to the second ligand is 80 - 100:0 - 20.

5. A method for preparing a nanomaterial, characterized in that, Comprising: Providing a quantum dot precursor, the quantum dot precursor including a metal source and an anion source, or including quantum dots and a second ligand connected to the surface of the quantum dots; Providing a solvent and a first ligand, the structural formula of the first ligand being: R-X, the X group including one or more of -COOD, -SD, -OD, -ND2, and the R including one or more of hydrogen, a substituted or unsubstituted C1-C24 alkyl group, a substituted or unsubstituted C2-C24 alkenyl group, a substituted or unsubstituted C2-C24 alkynyl group, a substituted or unsubstituted C1-C24 alkoxy group, a substituted or unsubstituted C1-C24 acyloxy group, a substituted or unsubstituted C1-C24 alkoxycarbonyl group, a substituted or unsubstituted C6-C24 aryl group, a substituted or unsubstituted C3-C24 heterocyclic group; the substituents of the substitution each independently include one or more of D, -NH2, -F, -Cl, -Br, -I, -OH, -COOH, -NO2, -SO3H, -CHO, -SH, -CN; mixing the solvent and the first ligand with the quantum dot precursor to obtain a nanomaterial.

6. The preparation method according to claim 5, characterized in that, The quantum dot precursor includes a metal source and an anion source, the solvent includes a first solvent; the preparation method includes: Mixing the metal source, the anion source with the first solvent and the first ligand to synthesize quantum dots and obtain a nanomaterial; Optionally, the metal source includes a first metal source, the first metal source including one or more of a cadmium source, a zinc source, a mercury source, a tin source, a lead source, a gallium source, an antimony source, an aluminum source, an indium source, a copper source; Optionally, the anion source includes a first anion source, the first anion source including one or more of a sulfur source, a selenium source, a tellurium source, a nitrogen source, an arsenic source, a phosphorus source; Optionally, the first solvent includes one or more of octadecene, paraffin oil, and stearic acid; Optionally, the temperature for synthesizing the quantum dots is 280 °C to 350 °C.

7. The preparation method according to claim 5, characterized in that, When the quantum dots are core-shell quantum dots, the metal source further includes a second metal source, and the anion source further includes a second anion source; The second metal source includes one or more of cadmium source, zinc source, mercury source, tin source, lead source, gallium source, antimony source, aluminum source, indium source, and copper source; and / or The second anion source includes one or more of sulfur source, selenium source, tellurium source, nitrogen source, arsenic source, and phosphorus source.

8. The preparation method according to claim 5, characterized in that, The quantum dot precursor includes quantum dots and a second ligand connected to the surface of the quantum dots, and the solvent includes a second solvent; the preparation method includes: Mixing the quantum dots and the second ligand connected to the surface of the quantum dots with the second solvent and the first ligand, and performing ligand exchange to obtain a nanomaterial.

9. The preparation method according to claim 8, characterized in that, The second ligand is one or more of oleic acid, mercaptoacetic acid, mercaptopropionic acid, 1,2-ethanedithiol, propanethiol, butanethiol, octanethiol, dodecanethiol, octadecanethiol, benzenethiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, and oleylamine; and / or The second solvent includes one or more of toluene, n-hexane, chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, N,N-dimethylformamide, ethyl acetate, pyrrole, butyric acid, and cresol; and / or The temperature for performing ligand exchange is 20 °C to 75 °C.

10. An optoelectronic device, characterized in that, It includes a first electrode, a light-emitting layer, and a second electrode that are sequentially stacked. The light-emitting layer includes the nanomaterial according to any one of claims 1 to 4, or includes the nanomaterial prepared by the preparation method according to any one of claims 5 to 9.

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