Photoelectric device, preparation method thereof and display device

Abstract

The invention discloses a photoelectric device, a preparation method thereof and a display device, and relates to the technical field of display. The photoelectric device comprises an anode, a photoelectric functional layer, a first electronic functional layer, a second electronic functional layer and a cathode which are sequentially stacked, the material of the first electronic functional layer comprises first inorganic nanoparticles and a first ligand, and the material of the second electronic functional layer comprises second inorganic nanoparticles. The photoelectric device provided by the invention is high in luminous efficiency.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and in particular, to an optoelectronic device, a preparation method thereof, and a display 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 their excellent display performances such as self-luminescence, simple structure, ultra-thinness, fast response speed, wide viewing angle, low power consumption, and flexible display, OLEDs have become the mainstream technology in the field of display technologies. QLEDs have the advantages of saturated emission light color and adjustable wavelength, and high photoluminescence and electroluminescence quantum yields. In recent years, they have become strong competitors of OLEDs.

[0003] The structures of traditional OLED and QLED devices generally include an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode. Under the action of an electric field, the holes generated by the anode and the electrons generated by the cathode of the light-emitting diode move, are respectively injected into the hole transport layer and the electron transport layer, and finally migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, thereby exciting the light-emitting molecules to finally generate visible light.

[0004] Therefore, the luminous efficiency of optoelectronic devices is relatively low and needs to be further improved. Summary of the Invention

[0005] In view of this, the present application provides an optoelectronic device, a preparation method thereof, and a display device.

[0006] An optoelectronic device according to an embodiment of the present application includes: an anode, an optoelectronic functional layer, a first electron functional layer, a second electron functional layer, and a cathode that are sequentially stacked.

[0007] The material of the first electron functional layer includes first inorganic nanoparticles and a first ligand, and the material of the second electron functional layer includes second inorganic nanoparticles.

[0008] Correspondingly, an embodiment of the present application further provides a preparation method of an optoelectronic device, including:

[0009] Providing a preform of an optoelectronic device, where the preform of the optoelectronic device includes an anode and an optoelectronic functional layer that are sequentially stacked;

[0010] Providing first inorganic nanoparticles and a first ligand, and disposing the first inorganic nanoparticles and the first ligand on the optoelectronic functional layer to form a first electron functional layer;

[0011] Providing second inorganic nanoparticles, and disposing the second inorganic nanoparticles on the first electron functional layer to form a second electron functional layer;

[0012] A cathode is formed on the second electronic functional layer to obtain an optoelectronic device;

[0013] Or,

[0014] An optoelectronic device preform is provided, and the optoelectronic device preform includes a cathode;

[0015] A second inorganic nanoparticle is provided, and the second inorganic nanoparticle is disposed on the cathode to form a second electronic functional layer;

[0016] A first inorganic nanoparticle and a first ligand are provided, and the first inorganic nanoparticle and the first ligand are disposed on the second electronic functional layer to form a first electronic functional layer;

[0017] An optoelectronic functional layer and an anode are formed on the first electronic functional layer to obtain an optoelectronic device.

[0018] Correspondingly, an embodiment of the present application further provides a display device, and the display device includes the above-mentioned optoelectronic device.

[0019] The optoelectronic device provided by the present application has high luminous efficiency. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 is a schematic structural diagram of the optoelectronic device provided by the embodiment of the present application;

[0022] Figure 2 is a flowchart of the preparation method of the optoelectronic device provided by the embodiment of the present application;

[0023] Figure 3 is a flowchart of the preparation method of another optoelectronic device provided by the embodiment of the present application.

[0024] Reference Signs:

[0025] Anode 10; Optoelectronic functional layer 20; First electronic functional layer 30; Second electronic functional layer 40; Cathode 50; Hole functional layer 60. Detailed Embodiments

[0026] 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.

[0027] 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 "comprising" 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.

[0028] In the present application, "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural.

[0029] 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 (s) or plural item (s). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both 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.

[0030] 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.

[0031] At present, inorganic nanoparticles such as zinc oxide nanoparticles ZnO are often used as the materials for the electron functional layer. Its conduction band energy level is beneficial to the injection of electrons from the cathode to the light-emitting layer, and its deeper valence band energy level can effectively block holes. However, the conduction band energy level position of zinc oxide nanoparticles is still lower than that of the blue light-emitting layer quantum dots, and there are surface defects of adsorbed oxygen on zinc oxide nanoparticles. During the operation of optoelectronic devices, the conduction band energy level difference between zinc oxide nanoparticles and the light-emitting layer makes electron injection relatively difficult, resulting in high turn-on and operating voltages of the devices; and the defect states on the surface of zinc oxide will lead to serious interfacial charge recombination, resulting in efficiency loss of optoelectronic devices.

[0032] The technical solution of this application is as follows:

[0033] In a first aspect, please refer to Figure 1 An embodiment of this application provides an optoelectronic device, including: an anode 10, an optoelectronic functional layer 20, a first electron functional layer 30, a second electron functional layer 40, and a cathode 50 that are sequentially stacked;

[0034] The material of the first electron functional layer 30 includes first inorganic nanoparticles and a first ligand, and the material of the second electron functional layer 40 includes second inorganic nanoparticles.

[0035] It should be noted that the first ligand is connected to the surface of the first inorganic nanoparticles.

[0036] In the optoelectronic device provided by this application, in the first electron functional layer 30 close to the optoelectronic functional layer 20, the first ligand contained can increase the conduction band energy level of the first inorganic nanoparticles, reduce the injection barrier for electrons to be injected from the first electron functional layer 30 into the optoelectronic functional layer 20, promote the recombination of electrons and holes, and improve the optoelectronic efficiency; and the first ligand in the first electron functional layer 30 can passivate the surface defects of the first inorganic nanoparticles, reducing the exciton quenching of the defect energy levels of the first inorganic nanoparticles on the optoelectronic functional layer 20; in addition, the second inorganic nanoparticles in the second electron functional layer 40 close to the cathode 50 can maintain a high electron mobility, which is beneficial to the injection of electrons from the cathode 50 to the second electron functional layer 40. This application steps the conduction band energy levels of the electron functional layers, which can alleviate the problem of difficult electron injection in optoelectronic devices, promote the injection and transmission of electrons, improve the electron mobility, thereby reducing the turn-on voltage of optoelectronic devices and improving the optoelectronic efficiency of optoelectronic devices.

[0037] In some embodiments, the number of carbon atoms in the main chain of the first ligand is 2 to 10.

[0038] Preferably, in some embodiments, the main chain of the first ligand has 2 to 6 carbon atoms. Within this range of the number of carbon atoms in the main chain, the first ligand is a short-chain ligand with appropriate steric hindrance, which can promote the close arrangement of the first inorganic nanoparticles and improve the compactness of the first electron functional layer.

[0039] In some embodiments, the main chain of the first ligand has 3 to 8 carbon atoms.

[0040] In some embodiments, the main chain of the first ligand has 4 to 5 carbon atoms.

[0041] In some embodiments, the first ligand contains a coordination group. The coordination group can passivate the surface defects of the first inorganic nanoparticles and reduce the exciton quenching of the defect energy levels of the first inorganic nanoparticles to the optoelectronic functional layer 20.

[0042] Furthermore, the coordination group includes one or more of amino group, carboxyl group, thiol group, hydroxyl group, cyano group, carbonyl group, ester group, amide group, ether group. The coordination group can coordinate with the first inorganic nanoparticles to cause dipole polarization on the surface of the first inorganic nanoparticles, thereby raising the conduction band energy level.

[0043] In some embodiments, the first ligand includes one or more of ethanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, ethylenediaminetetraacetic acid, 3-mercaptopropionic acid, benzenethiol, 2-(methylamino)ethanol, oxalic acid, malic acid, caffeic acid, benzyl mercaptan, 2-(Boc-amino)ethanethiol, diethylene glycol monoallyl ether, ethyl cyanoacetate, 4-cyanobenzoic acid.

[0044] In some embodiments, in the first electron functional layer 30, the molar ratio of the first inorganic nanoparticles to the first ligand is 1:(100 - 300), for example, it can be 1:120, 1:150, 1:180, 1:200, 1:220, 1:250, 1:280, etc. Within this range of the molar ratio, it is beneficial for the first ligand to adjust the conduction band energy level of the first inorganic nanoparticles and promote electron injection.

[0045] In some embodiments, the materials of the first inorganic nanoparticles and the second inorganic nanoparticles independently include 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 materials of the first undoped metal oxide particles include 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.

[0046] It should be noted that the materials of the first inorganic nanoparticles and the second inorganic nanoparticles may be the same or different.

[0047] Preferably, the materials of the first inorganic nanoparticles and the second inorganic nanoparticles are the same.

[0048] In some embodiments, the average particle size of the first inorganic nanoparticles is 3 nm to 20 nm, and can be, for example, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, etc.

[0049] In some embodiments, the average particle size of the second inorganic nanoparticles is 3 nm to 20 nm, and can be, for example, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, etc.

[0050] In some embodiments, the thickness of the first electronic functional layer 30 is 10 nm to 30 nm, and can be, for example, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, etc.

[0051] In some embodiments, the thickness of the second electronic functional layer 40 is 10 nm to 30 nm, and can be, for example, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, etc.

[0052] In some embodiments, the material of the second electronic functional layer 40 further includes a second ligand, and the second ligand includes one or more of an acetate ligand, a nitrate ligand, an oxalate ligand, a chloride ligand, a bromide ligand, and a diethyl ligand. It should be noted that the second ligand is mainly a ligand generated by an anion in a precursor introduced during the synthesis of the second inorganic nanoparticles.

[0053] It should be noted that the material of the first electronic functional layer 30 also further includes a small amount of a third ligand, and the third ligand includes one or more of an acetate ligand, a nitrate ligand, an oxalate ligand, a chloride ligand, a bromide ligand, and a diethyl ligand. Since it is difficult for the first ligand to completely displace the third ligand, there is a small amount of the third ligand.

[0054] It can be understood that the content of the third ligand in the first electronic functional layer 30 is less than the content of the second ligand in the second electronic functional layer 40.

[0055] In some embodiments, the optoelectronic device includes a light-emitting diode.

[0056] In some embodiments, the optoelectronic device further includes a hole functional layer 60, and the hole functional layer 60 is disposed between the anode 10 and the optoelectronic functional layer 20.

[0057] The hole functional layer 60 includes one or more of a hole injection layer and a hole transport layer.

[0058] The first electronic functional layer 30 and the second electronic functional layer 40 include one or more of an electron injection layer and an electron transport layer.

[0059] In some embodiments, the anode 10 and the cathode 50 each independently include one or more of a metal, a carbon material, and a metal oxide; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene, and carbon fibers; 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 more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO. The composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. Herein, " / " represents a laminated structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer, and an AZO layer laminated in sequence.

[0060] In some embodiments, the material of the optoelectronic functional layer 20 includes a light-emitting material, and the light-emitting material includes an organic light-emitting material or a quantum dot light-emitting material.

[0061] The organic light-emitting material can be selected from, but not limited to, CBP:Ir(mppy)3 (4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine iridium(III)]), TCTX:Ir(mmpy) (4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine iridium]), diaryl anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, TADF (thermally activated delayed) material, a polymer containing B-N covalent bonds, HLCT (hybrid local charge transfer excited state) material, Exciplex (excimer complex) light-emitting material, or one or more of them.

[0062] The quantum dot light-emitting material can be selected from, but not limited to, one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0063] 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, one or several of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The shell of the core-shell structure quantum dots includes one or more layers. The II-VI group compounds can be selected from, but not limited to, one or several 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 several 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 several 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 several of CuInS2, CuInSe2, and AgInS2.

[0064] As an example, the quantum dots of the core-shell structure may 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).

[0065] The perovskite semiconductor material may 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 AMX3, where A is a Cs + ion, M is a divalent metal cation selected from 2+ Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu - Cl - Br - I n-2 NH3 + or [NH3(CH2) n NH3] 2+ where n≥2, M is a divalent metal cation selected from 2+ Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu - Cl - Br -One or more of them.

[0066] In some embodiments, the material of the hole functional layer 60 includes one or more of 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, 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.

[0067] In a second aspect, please refer to Figure 2 , an embodiment of the present application further provides a method for manufacturing an optoelectronic device, including:

[0068] S11. Provide a preform of the optoelectronic device, where the preform of the optoelectronic device includes an anode 10 and an optoelectronic functional layer 20 that are sequentially stacked;

[0069] S12. Provide a first inorganic nanoparticle and a first ligand, and dispose the first inorganic nanoparticle and the first ligand on the optoelectronic functional layer 20 to form a first electron functional layer 30;

[0070] S13. Provide a second inorganic nanoparticle, and dispose the second inorganic nanoparticle on the first electron functional layer 30 to form a second electron functional layer 40;

[0071] S14. Form a cathode 50 on the second electron functional layer 40 to obtain the optoelectronic device.

[0072] It can be understood that the optoelectronic device obtained by the above manufacturing method is a normal-type optoelectronic device. Please refer to Figure 3 , the present application further provides a method for manufacturing an inverted-type optoelectronic device, including:

[0073] S21. Provide a preform of the optoelectronic device, where the preform of the optoelectronic device includes a cathode 50;

[0074] S22. Provide a second inorganic nanoparticle, and dispose the second inorganic nanoparticle on the cathode 50 to form a second electron functional layer 40;

[0075] S23. Provide a first inorganic nanoparticle and a first ligand, and dispose the first inorganic nanoparticle and the first ligand on the second electron functional layer 40 to form a first electron functional layer 30;

[0076] S24. Form an optoelectronic functional layer 20 and an anode 10 on the first electron functional layer 30 to obtain the optoelectronic device.

[0077] In S11:

[0078] In some embodiments, the preform of the optoelectronic device further includes a hole functional layer 60, and the hole functional layer 60 is disposed between the anode 10 and the optoelectronic functional layer 20.

[0079] In S12:

[0080] In some embodiments, the method for forming the first electron functional layer 30 includes:

[0081] Provide a mixture, which includes first inorganic nanoparticles and a first ligand. Set the mixture on the optoelectronic functional layer 20 to form a first electron functional layer 30.

[0082] In some embodiments, in the mixture, the molar ratio of the first inorganic nanoparticles to the first ligand is 1:(100 - 300), and can be, for example, 1:120, 1:150, 1:180, 1:200, 1:220, 1:250, 1:280, etc. Within the range of the molar ratio, it is beneficial for the first ligand to adjust the conduction band energy level of the first inorganic nanoparticles and promote electron injection.

[0083] In some embodiments, the method for preparing the mixture includes: providing a first inorganic nanoparticle dispersion liquid, which includes first inorganic nanoparticles; providing a first ligand; mixing the first inorganic nanoparticle dispersion liquid and the first ligand to obtain a mixture.

[0084] In some embodiments, in the first inorganic nanoparticle dispersion liquid, the mass concentration of the first inorganic nanoparticles is 15 mg / mL - 30 mg / mL, and can be, for example, 18 mg / mL, 20 mg / mL, 22 mg / mL, 25 mg / mL, 28 mg / mL, etc. Within the range of the mass concentration, it is beneficial for the dissolution and dispersion of the first inorganic nanoparticles.

[0085] In some embodiments, the mixing time of the first inorganic nanoparticle dispersion liquid and the first ligand is 10 min - 60 min, and can be, for example, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 55 min, 55 min, etc.; the temperature is 15°C - 60°C, and can be, for example, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 55°C, 55°C, etc.

[0086] Thus, under the mixing conditions, it is beneficial for the first inorganic nanoparticles and the first ligand to be in full contact.

[0087] In some embodiments, after setting the mixture on the optoelectronic functional layer 20, a first thermal annealing is further included.

[0088] Furthermore, the temperature of the first thermal annealing is 80°C - 100°C, and can be, for example, 82°C, 85°C, 88°C, 90°C, 92°C, 95°C, 98°C, etc.; the time is 20 min - 30 min, and can be, for example, 22 min, 24 min, 26 min, 28 min, etc.

[0089] Thus, under the conditions of the first thermal annealing, it is beneficial to fully remove the solvent in the mixture solution.

[0090] In S13:

[0091] In some embodiments, the method for forming the second electronic functional layer 40 includes:

[0092] Providing a second inorganic nanoparticle dispersion liquid, which includes second inorganic nanoparticles, and disposing the second inorganic nanoparticle dispersion liquid on the first electronic functional layer 30 to form the second electronic functional layer 40.

[0093] In some embodiments, in the second inorganic nanoparticle dispersion liquid, the mass concentration of the second inorganic nanoparticles is 15 mg / mL to 30 mg / mL, and for example, it can be 18 mg / mL, 20 mg / mL, 22 mg / mL, 25 mg / mL, 28 mg / mL, etc.

[0094] In some embodiments, after disposing the second inorganic nanoparticle dispersion liquid on the first electronic functional layer 30, a second thermal annealing is further included.

[0095] Furthermore, the temperature of the second thermal annealing is 80°C to 100°C, and for example, it can be 82°C, 85°C, 88°C, 90°C, 92°C, 95°C, 98°C, etc.; the time is 20 min to 30 min, and for example, it can be 22 min, 24 min, 26 min, 28 min, etc.

[0096] Thus, under the conditions of the first thermal annealing, it is beneficial to fully remove the solvent in the second inorganic nanoparticle dispersion liquid.

[0097] In some embodiments, the first inorganic nanoparticle dispersion liquid further includes a first solvent. The second inorganic nanoparticle dispersion liquid further includes a second solvent.

[0098] In some embodiments, the first solvent and the second solvent each independently include one or more of 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.

[0099] In a third aspect, an embodiment of the present application further provides a display device, and the display device includes the above optoelectronic device.

[0100] The display device can be any electronic product with a display function. The electronic product includes but is not limited to a smart phone, a tablet computer, a notebook computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing scale, a vehicle-mounted display, a television, or an e-book reader. Among them, the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0101] The following is a specific description of the present application through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application.

[0102] Embodiment 1

[0103] This embodiment provides an optoelectronic device, and the preparation method is as follows:

[0104] Clean the ITO conductive glass with a cleaner to initially remove the stains on the surface. Subsequently, ultrasonically clean it in deionized water, acetone, absolute ethanol, and deionized water for 20 minutes respectively to remove the impurities on the surface. Finally, dry it with high-purity nitrogen to obtain the ITO anode;

[0105] Place the ITO substrate on a spin coater and spin coat it with the prepared TFB solution. The spin coating speed is 3000 rpm and the time is 30 s; after spin coating, perform a thermal annealing treatment at 150 °C for 30 minutes to form a 30-nm hole transport layer;

[0106] Place the substrate with the spin-coated hole transport layer on a spin coater and spin coat it with the prepared CdSe quantum dot solution. The spin coating speed is 3000 rpm and the time is 30 s; after spin coating, perform a thermal annealing treatment at 80 °C for 30 minutes to form a light-emitting layer with a thickness of 40 nm;

[0107] Add zinc acetate dihydrate to DMF to form a solution with a total concentration of 0.5 mol / L. Dropwise add 0.5 mol / L KOH ethanol solution at room temperature, and continue to stir for 1 h to obtain a clear and transparent solution; use ethyl acetate as a precipitant to precipitate ZnO nanoparticles, collect them by centrifugation, and then dissolve and disperse them with an appropriate amount of ethanol to prepare a ZnO ethanol dispersion; add 15 mmol / mL of diethylenetriamine, and the molar ratio of ZnO to diethylenetriamine is 1:200; stir at 25 °C for 30 minutes and then filter with a 0.2-μm filter head to obtain a mixed solution; spin coat the mixed solution onto the light-emitting layer, the spin coating speed is 3000 rpm, the spin coating time is 30 s, and perform a thermal annealing at 100 °C for 20 minutes to form a first electron functional layer with a thickness of 20 nm;

[0108] Place the substrate coated with the first electron functional layer on a spin coater, spin coat the above ZnO ethanol dispersion into a film at a spin coating speed of 3000 rpm for 30 s, and perform thermal annealing at 80 °C for 30 min to form a second electron functional layer with a thickness of 20 nm;

[0109] Place the substrate deposited with each functional layer in an evaporation chamber, and thermally evaporate a 100-nm layer of metallic silver as the cathode through a mask plate;

[0110] Encapsulate to obtain an optoelectronic device.

[0111] Examples 2 - 3

[0112] Examples 2 - 3 are basically the same as Example 1, except that in Examples 2 - 3, diethylenetriamine is replaced with ethylenediaminetetraacetic acid and ethanolamine, respectively.

[0113] Examples 4 - 5

[0114] Examples 4 - 5 are basically the same as Example 1, except that

[0115] in Example 4, ZnO in both the first electron functional layer and the second electron functional layer is replaced with TiO2;

[0116] in Example 5, only ZnO in the first electron functional layer is replaced with TiO2.

[0117] Examples 6 - 7

[0118] Examples 6 - 7 are basically the same as Example 1, except that in Examples 6 - 7, the concentrations of diethylenetriamine are 15 mmol / mL (the molar ratio of ZnO to diethylenetriamine is 1:300) and 5 mmol / mL (the molar ratio of ZnO to diethylenetriamine is 1:100), respectively.

[0119] Examples 8 - 9

[0120] Examples 8 - 9 are basically the same as Example 1, except that in Examples 8 - 9, the mixing times of ZnO and diethylenetriamine are 60 min and 10 min, respectively.

[0121] Examples 10 - 11

[0122] Examples 10 - 11 are basically the same as Example 1, except that in Examples 10 - 11, the mixing temperatures of ZnO and diethylenetriamine are 60 °C and 15 °C, respectively.

[0123] Examples 12 - 13

[0124] Examples 12 to 13 are basically the same as Example 1, except that the thicknesses of the first electronic functional layer in Examples 12 to 13 are 30 nm and 10 nm, respectively.

[0125] Comparative Examples 1 to 3

[0126] Comparative Examples 1 to 3 are basically the same as Example 1, except that

[0127] Comparative Example 1 does not contain the first electronic functional layer; Comparative Example 2 does not contain the second electronic functional layer; in Comparative Example 3, the second electronic functional layer is close to the light-emitting layer, and the first electronic functional layer is close to the cathode.

[0128] The luminous efficiency C.E@ max and the turn-on voltage of Examples 1 to 13 and Comparative Examples 1 to 3 were respectively tested, and the results are shown in Table 1.

[0129] Among them, the luminous efficiency C.E@ max was calculated by testing with a Keithley 2400 high-precision digital source meter, an Ocean Optic USB2000+ spectrometer, and an LS-160 luminance meter;

[0130] The test method for the turn-on voltage is as follows: the voltage value when the luminance reaches 1 nit was obtained in the efficiency test system built with a Keithley 6485, which is the turn-on voltage.

[0131] Table 1

[0132]

[0133] As can be seen from Table 1:

[0134] From Examples 1 to 5 and Comparative Examples 1 to 3, it can be obtained that for the optoelectronic device provided by the present application, compared with Comparative Examples 1 to 3, the luminous efficiency has been significantly improved, and the turn-on voltage has been reduced. The double-layer electron transport layers prepared by conventional inorganic nanoparticles and inorganic nanoparticles containing the first ligand form a gradient of conduction band energy levels, which is beneficial to the injection and transport of electrons; in Comparative Example 2, inorganic nanoparticles containing the first ligand were used as the electron transport layer, and the performance of its optoelectronic device was slightly better than that of Comparative Example 1, but the effect was still worse than that of Example 1. This may be because it reduces the injection barrier between the electron transport layer and the light-emitting layer, but correspondingly increases the injection barrier between the cathode and the electron transport layer; in addition, the first ligands with different chain lengths will also affect the performance of the optoelectronic device. Among them, the chain length of the first ligand in Example 1 is moderate, and the performance of the optoelectronic device is relatively good;

[0135] It can be seen from Examples 1, 6 to 7 and Comparative Example 1 that within the scope provided by the present application, the content of the first ligand has a certain influence on the luminous efficiency and turn-on voltage of the optoelectronic device. When the content of the first ligand is appropriate, the optoelectronic device has higher luminous efficiency and lower turn-on voltage.

[0136] It can be seen from Examples 1, 8 to 11 and Comparative Example 1 that within the scope provided by the present application, the mixing conditions of the first ligand and the first inorganic nanoparticles have a certain influence on the luminous efficiency and turn-on voltage of the optoelectronic device. Among them, the mixing temperature has a greater influence on the performance of the optoelectronic device and will affect the connection between the first ligand and the first inorganic nanoparticles. However, overall, the luminous efficiency of the optoelectronic devices in Examples 8 to 11 has been significantly improved, and the turn-on voltage has also decreased.

[0137] It can be seen from Examples 1, 12 to 13 and Comparative Example 1 that the thickness of the electron transport layer containing the first ligand has no significant influence on the performance of the optoelectronic device. The electron transport layer without the first ligand and the electron transport layer containing the first ligand can make the conduction band energy level of the overall electron transport layer stepped, alleviating problems such as low electron mobility and difficult electron injection. After the conduction band energy level is stepped, it can promote electron injection, reduce the turn-on voltage, and improve the luminous efficiency of the optoelectronic device.

[0138] The optoelectronic device, its preparation method, and the display device provided by the embodiments of the present application have been introduced in detail above. Specific examples are used in this article 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 method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. An optoelectronic device, characterized in that, Comprising: An anode, an optoelectronic functional layer, a first electronic functional layer, a second electronic functional layer, and a cathode that are stacked in sequence; The material of the first electronic functional layer includes first inorganic nanoparticles and a first ligand, and the material of the second electronic functional layer includes second inorganic nanoparticles.

2. The optoelectronic device according to claim 1, wherein In the first electronic functional layer, the molar ratio of the first inorganic nanoparticles to the first ligand is 1:(100 - 300); and / or The number of carbon atoms in the main chain of the first ligand is 2 - 10; and / or The first ligand contains a coordination group, and the coordination group includes one or more of an amino group, a carboxyl group, a thiol group, a hydroxyl group, a cyano group, a carbonyl group, an ester group, an amide group, and an ether group.

3. The optoelectronic device according to any one of claims 1 or 2, wherein The number of carbon atoms in the main chain of the first ligand is 2 - 6; and / or The first ligand includes one or more of ethanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, ethylenediaminetetraacetic acid, 3-mercaptopropionic acid, benzenethiol, 2-(methylamino)ethanol, oxalic acid, malic acid, caffeic acid, benzyl mercaptan, 2-(Boc-amino)ethanethiol, diethylene glycol monoallyl ether, ethyl cyanoacetate, 4-cyanobenzoic acid; and / or The materials of the first inorganic nanoparticles and the second inorganic nanoparticles each independently include 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, Ta2O5. The metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, 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, Ga. The IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor materials include one or more of InP, GaP. The IB-IIIA-VIA group semiconductor materials include one or more of CuInS, CuGaS.

4. The optoelectronic device according to claim 1, wherein The materials of the first inorganic nanoparticles and the second inorganic nanoparticles are the same or different; and / or The average particle size of the first inorganic nanoparticles is 3nm - 20nm; and / or The average particle size of the second inorganic nanoparticles is 3nm - 20nm; and / or The thickness of the first electronic functional layer is 10nm - 30nm; and / or The thickness of the second electronic functional layer is 10nm - 30nm; and / or The material of the second electronic functional layer further includes a second ligand, and the second ligand includes one or more of acetate ligand, nitrate ligand, oxalate ligand, chloride ligand, bromide ligand, and diethyl ligand; and / or The material of the first electronic functional layer further includes a third ligand, and the third ligand includes one or more of acetate ligand, nitrate ligand, oxalate ligand, chloride ligand, bromide ligand, and diethyl ligand.

5. The optoelectronic device according to claim 1, wherein The anode and the cathode each independently include one or more of a metal, a carbon material, and a metal oxide; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes one or more of graphite, carbon nanotubes, 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, and the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The material of the optoelectronic functional layer includes a luminescent material, and the luminescent material includes an organic luminescent material or a quantum dot luminescent material; the organic luminescent material is selected from one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium], diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, TADF material, polymers containing B-N covalent bonds, HLCT material, Exciplex luminescent material; the quantum dot luminescent material is selected from 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 respectively 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 shell layer of the core-shell structure quantum dots includes one or more layers; the II-VI group compounds are selected from 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 are selected from one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe;The III-V compound is selected from 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 compound is selected from one or more of CuInS2, CuInSe2 and AgInS2; the core-shell structure quantum dots are selected from one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS; the perovskite semiconductor material is selected from doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the structural general formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + ion, M is a divalent metal cation selected from 2+ Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu - one or more of Cl - Br - I 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, X is a halogen anion selected from Cl - 、Br - 、I - one or more of; and / or The optoelectronic device further includes a hole functional layer, and the hole functional layer is disposed between the anode and the optoelectronic functional layer;The materials of the hole functional layer include one or more of 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. The metal oxides in the second doped metal oxide particles and the metal oxides in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, 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. The metal nitrides include p-type gallium nitride.; 6. A method for preparing an optoelectronic device, characterized in that, Comprising: Providing an optoelectronic device preform, the optoelectronic device preform including an anode and an optoelectronic functional layer stacked in sequence; Providing a first inorganic nanoparticle and a first ligand, and disposing the first inorganic nanoparticle and the first ligand on the optoelectronic functional layer to form a first electronic functional layer; Providing a second inorganic nanoparticle, and disposing the second inorganic nanoparticle on the first electronic functional layer to form a second electronic functional layer; Forming a cathode on the second electronic functional layer to obtain an optoelectronic device; Or, Providing an optoelectronic device preform, the optoelectronic device preform including a cathode; Providing a second inorganic nanoparticle, and disposing the second inorganic nanoparticle on the cathode to form a second electronic functional layer; Providing a first inorganic nanoparticle and a first ligand, and disposing the first inorganic nanoparticle and the first ligand on the second electronic functional layer to form a first electronic functional layer; Forming an optoelectronic functional layer and an anode on the first electronic functional layer to obtain an optoelectronic device.

7. The preparation method according to claim 6, wherein The main chain of the first ligand has 2 to 10 carbon atoms; and / or The first ligand contains a coordination group, and the coordination group includes one or more of amino group, carboxyl group, thiol group, hydroxyl group, cyano group, carbonyl group, ester group, amide group, and ether group; and / or The first ligand includes one or more of ethanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, ethylenediaminetetraacetic acid, 3-mercaptopropionic acid, benzenethiol, 2-(methylamino)ethanol, oxalic acid, malic acid, caffeic acid, benzyl mercaptan, 2-(Boc-amino)ethyl mercaptan, diethylene glycol monoallyl ether, ethyl cyanoacetate, 4-cyanobenzoic acid; and / or The first inorganic nanoparticles and the second inorganic nanoparticles each independently include 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, Ta2O5. The metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, 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, Ga. The IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor materials include one or more of InP, GaP. The IB-IIIA-VIA group semiconductor materials include one or more of CuInS, CuGaS.

8. The preparation method according to claim 6, wherein The method for forming the first electron functional layer includes: providing a mixed solution including the first inorganic nanoparticles and the first ligand, and disposing the mixed solution on the optoelectronic functional layer to form the first electron functional layer; and / or The method for forming the second electron functional layer includes: providing a second inorganic nanoparticle dispersion including the second inorganic nanoparticles, and disposing the second inorganic nanoparticle dispersion on the first electron functional layer to form the second electron functional layer.

9. The preparation method according to claim 8, wherein In the mixed solution, the molar ratio of the first inorganic nanoparticles to the first ligand is 1:(100-300); and / or After disposing the mixed solution on the optoelectronic functional layer, a first thermal annealing is further included. The temperature of the first thermal annealing is 80°C to 100°C; the time is 20 min to 30 min; and / or In the second inorganic nanoparticle dispersion, the mass concentration of the second inorganic nanoparticles is 15 mg / mL to 30 mg / mL; and / or After disposing the second inorganic nanoparticle dispersion on the first electron functional layer, a second thermal annealing is further included. The second thermal annealing is at 80°C to 100°C; the time is 20 min to 30 min.

10. The preparation method according to claim 8, characterized in that, The preparation method of the mixed solution includes: Provide a first inorganic nanoparticle dispersion, which includes first inorganic nanoparticles; Provide a first ligand; mix the first inorganic nanoparticle dispersion and the first ligand to obtain a mixed solution.

11. The preparation method according to claim 10, wherein in the first inorganic nanoparticle dispersion, the mass concentration of the first inorganic nanoparticles is 15 mg / mL to 30 mg / mL; and / or the mixing time of the first inorganic nanoparticle dispersion and the first ligand is 10 min to 60 min; the temperature is 15 °C to 60 °C; and / or the first inorganic nanoparticle dispersion further includes a first solvent; the first solvent includes one or more of 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 second inorganic nanoparticle dispersion further includes a second solvent; the second solvent includes one or more of 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.

12. A display device, characterized in that, Include the optoelectronic device according to any one of claims 1 to 5, or include the optoelectronic device prepared by the preparation method according to any one of claims 6 to 11.

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