Thin film and preparation method thereof, photoelectric device and display device

Abstract

The invention discloses a thin film and a preparation method thereof, a photoelectric device and a display device, and relates to the technical field of display. The preparation method of the thin film comprises the steps that a base film is provided, materials of the base film comprise inorganic nanoparticles and impurities, and the impurities comprise organic compounds; and circulating carbon dioxide gas to the surface of the base film to obtain the film. According to the preparation method of the film, the carbon dioxide gas can take away the organic compound, the content of the organic compound is reduced, the organic compound is prevented from influencing the excellent performance of the film, the service life of the film is prolonged, and the chemical stability of the film is improved.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a thin film, a preparation method thereof, an optoelectronic device, 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 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 field of display technologies. 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] 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 of the light-emitting diode and the electrons generated by the cathode 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] Currently, 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 a thin film, a preparation method thereof, an optoelectronic device, and a display device, aiming to improve the problem of relatively low luminous efficiency of existing optoelectronic devices.

[0006] In an embodiment of the present application, a preparation method of a thin film is implemented as follows: a base film is provided, and the material of the base film includes inorganic nanoparticles and impurities, and the impurities include organic compounds;

[0007] Carbon dioxide gas is circulated on the surface of the base film to obtain a thin film.

[0008] Optionally, in some embodiments of the present application, the circulation of carbon dioxide gas on the surface of the base film is carried out under heating conditions, and the heating temperature is 10°C to 150°C; and / or

[0009] the purity of the carbon dioxide gas is 99% to 100%; and / or

[0010] the gas flow rate of the carbon dioxide gas is 5 L / min to 60 L / min; and / or

[0011] the time for circulating the carbon dioxide gas on the surface of the base film is 10 min to 30 min; and / or

[0012] The circulation of carbon dioxide gas on the surface of the base film is carried out in an inert atmosphere, and the inert gas in the inert atmosphere includes one or more of nitrogen, argon, helium, neon, krypton, and xenon.

[0013] Optionally, in some embodiments of the present application, the inorganic nanoparticles 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; and / or

[0014] The average particle size of the inorganic nanoparticles is 2 nm to 15 nm; and / or

[0015] The impurities further include inorganic bases; and / or

[0016] The thickness of the base film is 40 nm to 60 nm.

[0017] Optionally, in some embodiments of the present application, the method for preparing the base film includes:

[0018] Providing an inorganic nanoparticle dispersion liquid, which includes inorganic nanoparticles and a solvent;

[0019] Providing a substrate, and disposing the inorganic nanoparticle dispersion liquid on the substrate to obtain a base film.

[0020] Optionally, in some embodiments of the present application, the solvent includes one or more of benzene, carbon tetrachloride, diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, 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

[0021] In the inorganic nanoparticle dispersion liquid, the mass concentration of the inorganic nanoparticles is 25 mg / mL to 35 mg / mL.

[0022] Optionally, in some embodiments of the present application, after the inorganic nanoparticle dispersion liquid is disposed on the substrate, annealing is further included; the temperature of the annealing is 75 °C to 85 °C, and the time is 5 min to 10 min.

[0023] Correspondingly, an embodiment of the present application further provides a thin film prepared by the above preparation method.

[0024] Optionally, in some embodiments of the present application, the material of the thin film includes inorganic nanoparticles and carbonates.

[0025] Optionally, in some embodiments of the present application, the carbonates include one or more of zinc carbonate, barium carbonate, nickel carbonate, titanium carbonate, tin carbonate, tantalum carbonate, zirconium carbonate, cadmium carbonate, molybdenum carbonate, tungsten carbonate, copper carbonate, indium carbonate, gallium carbonate, barium carbonate, aluminum carbonate, magnesium carbonate, lithium carbonate, manganese carbonate, yttrium carbonate, lanthanum carbonate, cerium carbonate, and gadolinium carbonate.

[0026] Correspondingly, an embodiment of the present application further provides an optoelectronic device, including: an anode, a light-emitting layer, an electron functional layer, and a cathode that are sequentially stacked, wherein the electron functional layer includes the thin film prepared by the above preparation method or includes the above thin film.

[0027] Optionally, in some embodiments of the present application, the materials of the anode and the cathode each independently include one or more of metals, carbon materials, and metal oxides; the metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include 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, and the composite electrodes include 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

[0028] The materials of the light-emitting layer include 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 materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescence materials, TTA materials, TADF materials, polymers containing B-N covalent bonds, HLCT materials, Exciplex light-emitting materials, 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, HgZnSTe, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, 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, InAlPSb, CuInS2, CuInSe2, AgInS2, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, InP / ZnSe / ZnS, AMX3 and BMX3, where A is Cs+ an 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+ or one or more of the following, X is a halogen anion selected from Cl - 、Br - 、I - or one or more of the following; B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n ≥ 2; and / or

[0029] The optoelectronic device further includes a hole functional layer, and the hole functional layer is disposed between the anode and the light-emitting 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-ethylhexoxy)-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 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. The metal nitrides include p-type gallium nitride.;

[0030] Correspondingly, an embodiment of the present application further provides a display device, and the display device includes the above-mentioned optoelectronic device.

[0031] In the method for preparing the thin film provided by the present application, carbon dioxide gas treatment can reduce the content of organic compounds, so as to improve the service life and chemical stability of the thin film, thereby improving the current efficiency and service life of the optoelectronic device. Description of the Drawings

[0032] 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 drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0033] Figure 1 It is a flowchart of the method for preparing the thin film provided by the embodiment of the present application;

[0034] Figure 2 It is a schematic structural diagram of the optoelectronic device provided by the embodiment of the present application;

[0035] Figure 3 It is a schematic structural diagram of another optoelectronic device provided by the embodiment of the present application.

[0036] Reference Signs:

[0037] Anode 10; Light-emitting layer 20; Electron functional layer 30; Cathode 40, Hole functional layer 50. Detailed Embodiments

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all 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 embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0039] 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 drawings; and "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.

[0040] In this application, "and / or" describes the association relationship of associated objects, indicating 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. Where A and B can be singular or plural.

[0041] In this application, "at least one" means one or more, and "a plurality" means two or more. "One or several", "at least one of the following (item)" 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 of a, b, or c", or, "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0042] The various embodiments of this application can 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 this application; therefore, it should be considered that the range description has specifically disclosed all possible sub - ranges and 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 single numbers within that range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0043] Zinc oxide is a semiconductor material with a direct wide bandgap and has very excellent electron migration performance. The addition of Mg can adjust the energy level injection of zinc oxide to make it more suitable for the electron injection of quantum dots. However, the doping efficiency of Mg is not 100%, and the conversion rate of Zn raw materials is not 100% either. During the synthesis of zinc oxide, only a part of the added Mg precursor is often converted into dopants or adherents and acts on the energy level regulation of zinc oxide. More Mg elements exist in the magnesium - doped zinc oxide in the form of the original Mg precursor or Mg semi - product, and the Zn precursor cannot be guaranteed to be completely removed. That is to say, magnesium - doped zinc oxide is actually a mixture carrying a large amount of Zn and Mg impurities, and these Mg precursors or Mg semi - products with poor chemical stability will cause the stability of optoelectronic devices to decline after film formation, resulting in varying degrees of electrical property changes in optoelectronic devices, causing fluctuations in the carrier transport efficiency and affecting the stability and lifespan of the use of optoelectronic devices.

[0044] The technical solution of this application is as follows:

[0045] In a first aspect, please refer toFigure 1 , an embodiment of the present application provides a method for preparing a thin film, including:

[0046] S11. Provide a base film, the material of the base film includes inorganic nanoparticles and impurities, and the impurities include organic compounds;

[0047] S12. Circulate carbon dioxide gas on the surface of the base film to obtain a thin film.

[0048] It should be noted that during the preparation of the inorganic nanoparticles, the inorganic nanoparticle precursor can be an organic salt. For example, in the preparation of zinc oxide inorganic nanoparticles, its precursor can be zinc acetate, and an organic solvent is required to dissolve and provide a reaction environment. Organic solvents such as benzene and carbon tetrachloride are used. During the process of the inorganic nanoparticle precursor reacting to form inorganic nanoparticles, it is difficult to achieve complete reaction, and it is difficult to completely remove the organic solvent. Therefore, some organic compounds will be mixed in the inorganic nanoparticles.

[0049] In the method for preparing a thin film provided by the present application, by circulating carbon dioxide gas on the surface of the base film, compared with the polarity of the inorganic nanoparticles, the polarity of carbon dioxide gas is closer to that of the organic compounds, so that the carbon dioxide gas can carry away the organic compounds, reduce the content of the organic compounds, and avoid the influence of the organic compounds on the excellent performance of the thin film, so as to improve the service life and chemical stability of the thin film.

[0050] In S11:

[0051] In some embodiments, the inorganic nanoparticles 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.

[0052] In some embodiments, the average particle size of the inorganic nanoparticles is 2 nm to 15 nm, and for example, it can be 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, etc.

[0053] It can be understood that the inorganic nanoparticles can be one or several of nanospheres, nanosheets, and nanorods.

[0054] In some embodiments, the impurities further include inorganic bases. It can be understood that during the preparation of the inorganic nanoparticles, an alkali needs to be added, and the OH in the alkali - will react with the metal in the inorganic nanoparticle precursor to generate inorganic bases, such as zinc hydroxide, etc. By introducing carbon dioxide gas, carbon dioxide can chemically react with the inorganic base to generate carbonates. For example, carbon dioxide reacts with zinc hydroxide to generate zinc carbonate, etc., blocking the corrosion of the film by the inorganic base and further improving the chemical stability of the film layer. It should be noted that the inorganic base is in a small amount, and the generated carbonate is also in a small amount. The carbonate and the inorganic nanoparticles are mixed irregularly and jointly serve as the material of the film. The negative effect of the small amount of carbonate on the performance of the inorganic nanoparticles is much smaller than the positive effect brought by blocking the corrosion of the film by the inorganic base. Therefore, the carrier transport performance of the film can still be effectively ensured.

[0055] It can be understood that the base film can adopt conventional techniques in the art, such as chemical methods or physical methods. Among them, chemical methods include chemical vapor deposition, sequential ionic layer adsorption and reaction, anodic oxidation, electrodeposition, coprecipitation. Physical methods include physical coating methods and solution methods. Among them, physical coating methods include: thermal evaporation coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion coating method, physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc.; the solution method can be spin coating method, printing method, inkjet printing method, doctor blade coating method, printing method, dip coating method, immersion method, spraying method, roll coating method, casting method, slot die coating method, and bar coating method, etc.

[0056] In at least one embodiment, the preparation method of the base film is the solution method. Specifically, the preparation method includes:

[0057] S111. Provide an inorganic nanoparticle dispersion liquid, where the inorganic nanoparticle dispersion liquid includes inorganic nanoparticles and a solvent;

[0058] S112. Provide a substrate, and dispose the inorganic nanoparticle dispersion liquid on the substrate to obtain a base film.

[0059] In S111:

[0060] In some embodiments, the solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, N,N-dimethylformamide, ethyl acetate, pyrrole, butyric acid, and cresol.

[0061] In some embodiments, in the inorganic nanoparticle dispersion liquid, the mass concentration of the inorganic nanoparticles is 25 mg / mL to 35 mg / mL, and can be, for example, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL, 30 mg / mL, 31 mg / mL, 32 mg / mL, 33 mg / mL, 34 mg / mL, etc. Within the range of the mass concentration, it is beneficial to the full dissolution of the inorganic nanoparticles.

[0062] In S112:

[0063] In some embodiments, the substrate is a preform of an optoelectronic device, and the preform of the optoelectronic device includes an anode 10 and a light-emitting layer 20 stacked in sequence.

[0064] In some embodiments, the flowing of carbon dioxide gas on the surface of the base film is carried out under heating conditions, and the heating temperature is 10 °C to 150 °C, and can be, for example, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, etc. Within the range of the temperature, it is beneficial to the release of the impurities, thereby promoting the reaction between the impurities and the carbon dioxide gas to remove the impurities.

[0065] In some embodiments, after the inorganic nanoparticle dispersion liquid is disposed on the substrate, annealing is further included.

[0066] Furthermore, the annealing temperature is 75 °C to 85 °C, and can be, for example, 76 °C, 77 °C, 78 °C, 79 °C, 80 °C, 81 °C, 82 °C, 83 °C, 84 °C, etc. The annealing time is 5 min to 10 min, and can be, for example, 6 min, 7 min, 8 min, 9 min, etc.

[0067] In this way, under the annealing conditions, most of the organic solvents in the inorganic nanoparticle dispersion liquid can be removed.

[0068] In some embodiments, the thickness of the base film is 40 nm to 60 nm, and can be, for example, 42 nm, 45 nm, 48 nm, 50 nm, 52 nm, 55 nm, 58 nm, etc.

[0069] In S12:

[0070] In some embodiments, the purity of the carbon dioxide gas is 99% to 100%, for example, it can be 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.1%, 99.9%, etc. It should be noted that when the purity of the carbon dioxide gas is less than 100%, in addition to the carbon dioxide gas in the gas, the remaining part is an inert gas, such as argon, etc.

[0071] In some embodiments, the gas flow rate of the carbon dioxide gas is 5 L / min to 60 L / min, for example, it can be 10 L / min, 15 L / min, 20 L / min, 25 L / min, 30 L / min, 35 L / min, 40 L / min, 45 L / min, 50 L / min, 55 L / min, etc. Within the range of the gas flow rate, it is beneficial for the carbon dioxide gas to effectively carry away organic compounds.

[0072] In some embodiments, the time for the carbon dioxide gas to flow on the surface of the base film is 10 min to 30 min, for example, it can be 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, etc. Within the range of the gas flow rate, it is beneficial for the carbon dioxide gas to fully contact the organic compounds in the base film.

[0073] In some embodiments, the flow of the carbon dioxide gas on the surface of the base film is carried out in an inert atmosphere. In this way, the influence of other gas components on the base film can be avoided, and it is ensured that the carbon dioxide gas can effectively carry away organic compounds.

[0074] Furthermore, the inert gas in the inert atmosphere includes one or more of nitrogen, argon, helium, neon, krypton, and xenon.

[0075] That is to say, during the process of treating the base film with the carbon dioxide gas, the environment only contains inert gas and carbon dioxide gas, and no other impurity gases.

[0076] In a second aspect, an embodiment of the present application further provides a thin film prepared by the above-mentioned thin film preparation method.

[0077] In some embodiments, the material of the thin film includes inorganic nanoparticles and carbonates.

[0078] Further, the carbonate includes one or more of zinc carbonate, barium carbonate, nickel carbonate, titanium carbonate, tin carbonate, tantalum carbonate, zirconium carbonate, cadmium carbonate, molybdenum carbonate, tungsten carbonate, copper carbonate, indium carbonate, gallium carbonate, barium carbonate, aluminum carbonate, magnesium carbonate, lithium carbonate, manganese carbonate, yttrium carbonate, lanthanum carbonate, cerium carbonate, and gadolinium carbonate.

[0079] In a third aspect, please refer to Figure 2 , an optoelectronic device is further provided in an embodiment of the present application, including: an anode 10, a light-emitting layer 20, an electron functional layer 30, and a cathode 40 that are sequentially stacked, wherein the electron functional layer 30 includes a thin film prepared by the above preparation method or includes the above thin film.

[0080] It can be understood that the electron functional layer 30 has been treated with carbon dioxide gas. When the cathode 40 is further provided on the electron functional layer 30, the interface between the electron functional layer 30 and the cathode 40 can be improved, impurities can be reduced, the service life and transmission stability of the electron functional layer 30 can be improved, and further the service life and reliability of the optoelectronic device can be improved.

[0081] In some embodiments, please refer to Figure 3 , the optoelectronic device further includes a hole functional layer 50, and the hole functional layer 50 is disposed between the anode 10 and the light-emitting layer 20.

[0082] Further, the hole functional layer 50 includes one or more of a hole injection layer and a hole transport layer.

[0083] The electron functional layer 30 includes one or more of an electron injection layer and an electron transport layer.

[0084] In some embodiments, the thickness of the anode 10 is 115 nm to 125 nm, and for example, it can be 116 nm, 117 nm, 118 nm, 119 nm, 120 nm, 121 nm, 122 nm, 123 nm, 124 nm, etc.

[0085] In some embodiments, the thickness of the hole injection layer is 70 nm to 90 nm, and for example, it can be 72 nm, 75 nm, 78 nm, 80 nm, 82 nm, 85 nm, 88 nm, etc.

[0086] In some embodiments, the thickness of the hole transport layer is 70 nm to 90 nm, and for example, it can be 72 nm, 75 nm, 78 nm, 80 nm, 82 nm, 85 nm, 88 nm, etc.

[0087] In some embodiments, the thickness of the light-emitting layer 20 is 60 nm to 80 nm, and for example, it can be 62 nm, 65 nm, 68 nm, 70 nm, 72 nm, 75 nm, 78 nm, etc.

[0088] In some embodiments, the thickness of the electronic functional layer 30 is 40 nm to 60 nm, and for example, it can be 42 nm, 45 nm, 48 nm, 50 nm, 52 nm, 55 nm, 58 nm, etc.

[0089] In some embodiments, the thickness of the cathode 40 is 55 nm to 65 nm, and for example, it can be 56 nm, 57 nm, 58 nm, 59 nm, 60 nm, 61 nm, 62 nm, 63 nm, 64 nm, etc.

[0090] In some embodiments, the materials of the anode 10 and the cathode 40 independently include one or more of metals, carbon materials, and metal oxides; the metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include metal oxide electrodes or composite electrodes with a metal sandwiched between doped or undoped transparent metal oxides. The materials of the metal oxide electrodes include one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO, and the composite electrodes include 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.

[0091] In some embodiments, the material of the light-emitting layer 20 includes one or more of organic light-emitting materials and quantum dot light-emitting materials.

[0092] The organic light-emitting materials include one or more of 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 materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescence materials, TTA materials, TADF (thermally activated delayed) materials, polymers containing B-N covalent bonds, HLCT (hybrid local charge transfer excited state) materials, and Exciplex (excimer complex) light-emitting materials.

[0093] The quantum dot light-emitting material includes one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0094] 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 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 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.

[0095] As an example, the quantum dots of the core-shell structure include 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.

[0096] The perovskite semiconductor material includes 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 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 the above, and X is a halogen anion selected from Cl - , Br - , I - and one or more of the above. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2 + , Eu 2+ and one or more of the above, and X is a halogen anion selected from Cl - , Br - , I - and one or more of the above.

[0097] In some embodiments, the material of the hole functional layer 50 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 light-emitting 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 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. The metal nitrides include p-type gallium nitride.

[0098] In a fourth aspect, an embodiment of the present application further provides a display device, and the display device includes the above-mentioned optoelectronic device.

[0099] 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 laptop computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic 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.

[0100] 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.

[0101] Embodiment 1

[0102] This embodiment provides an optoelectronic device, and the preparation method is as follows:

[0103] 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 minutes, and then dry it with nitrogen and irradiate it with UV for 15 minutes to form an ITO anode with a thickness of 120 nm;

[0104] Spin-coat PEDOT:PSS on the ITO anode at a rotation speed of 3000 rpm, and then anneal it at 150 °C for 20 minutes to form a hole injection layer with a thickness of 80 nm;

[0105] Dissolve TFB in chlorobenzene at a concentration of 8 mg / mL, spin-coat it on the hole injection layer at a rotation speed of 3500 rpm, and then anneal it at 150 °C for 30 minutes to form a hole transport layer with a thickness of 80 nm;

[0106] Spin-coat CdSeS / ZnS green quantum dots with octanethiol ligands on the hole transport layer at a rotation speed of 2800 rpm, and then anneal it at 100 °C for 5 minutes to form a light-emitting layer with a thickness of 70 nm;

[0107] Spin-coat an ethanol solution of zinc oxide at 30 mg / mL on the light-emitting layer and place it at 80 °C for 10 minutes to completely dry the zinc oxide film layer. Place the device in an argon atmosphere, and at 60 °C, continuously introduce a CO2 gas stream with a purity of 99.5% at a flow rate of 30 L / min on the surface of the zinc oxide film layer, and the remaining part is argon, for 10 minutes to form an electron transport layer with a thickness of 50 nm;

[0108] On the electron transport layer, turn on the Ag target, and the Ag target is at Evaporate at a rate to form a cathode with a thickness of 60 nm;

[0109] Encapsulate to obtain an optoelectronic device.

[0110] Example 2

[0111] This example is basically the same as Example 1, except that in this example, zinc oxide is replaced by magnesium-doped zinc oxide, and the doping ratio of magnesium is 10%.

[0112] Example 3

[0113] This example is basically the same as Example 1, except that in this example, zinc oxide is replaced by barium oxide.

[0114] Example 4

[0115] This example is basically the same as Example 1, except that in this example, the purity of the CO2 gas stream is 99%, and the remaining part is argon.

[0116] Example 5

[0117] This example is basically the same as Example 1, except that in this example, the purity of the CO2 gas stream is 100%.

[0118] Example 6

[0119] This example is basically the same as Example 1, except that in this example, the gas flow rate of the CO2 gas stream is 5 L / min.

[0120] Example 7

[0121] This example is basically the same as Example 1, except that in this example, the gas flow rate of the CO2 gas stream is 60 L / min.

[0122] Example 8

[0123] This example is basically the same as Example 1, except that in this example, the time for introducing the CO2 gas stream is 20 min.

[0124] Example 9

[0125] This example is basically the same as Example 1, except that in this example, the time for introducing the CO2 gas stream is 30 min.

[0126] Example 10

[0127] This example is basically the same as Example 1, except that in this example, the temperature for introducing the CO2 gas stream is 150 °C.

[0128] Example 11

[0129] This embodiment is basically the same as Embodiment 1, except that the temperature of the CO2 gas flow introduced in this embodiment is 10°C.

[0130] Embodiment 12

[0131] This embodiment is basically the same as Embodiment 1, except that the temperature of the CO2 gas flow introduced in this embodiment is 80°C.

[0132] Embodiment 13

[0133] This embodiment is basically the same as Embodiment 1, except that the temperature of the CO2 gas flow introduced in this embodiment is 50°C.

[0134] Comparative Example 1

[0135] This comparative example is basically the same as Embodiment 1, except that in this comparative example, the zinc oxide film layer is not treated with a CO2 gas flow.

[0136] Comparative Example 2

[0137] This comparative example is basically the same as Embodiment 1, except that in this comparative example, the CO2 gas flow is replaced with solid CO2.

[0138] Comparative Example 3

[0139] This comparative example is basically the same as Embodiment 1, except that in this comparative example, the CO2 gas flow is replaced with liquid CO2.

[0140] Comparative Example 4

[0141] This comparative example is basically the same as Embodiment 1, except that in this comparative example, after spin-coating the ethanol solution of zinc oxide, a mixed gas of CO, oxygen, water vapor, and CO2 is directly introduced on the surface of the ethanol solution of zinc oxide.

[0142] Perform T95@1k nit, luminous efficiency (C.E.), and on / off efficiency fluctuation tests on the optoelectronic devices of Embodiments 1 to 13 and Comparative Examples 1 to 4. The test results are shown in Table 1.

[0143] Among them, the test method for T95@1k nit is as follows:

[0144] The time required for the device to reduce the brightness to a certain proportion of the maximum brightness under constant current or voltage drive. The time when the brightness drops to 95% of the maximum brightness is defined as T95, and this life is the measured life. To shorten the test cycle, the device life test is usually carried out by accelerating the device aging at high brightness and obtaining the life at high brightness through fitting with an extended exponential decay brightness decay fitting formula. For example, the life at 1000 nit is denoted as T95@1000 nit. The specific calculation formula is as follows:

[0145]

[0146] Among them, T95 L is the lifespan at low brightness, and T95 H is the measured lifespan at high brightness. L H is when the device is accelerated to the highest brightness. L L is 1000 nit, A is the acceleration factor. In this experiment, the value of A is obtained as 1.7 by measuring the lifespans of several groups of green QLED devices at the rated brightness.

[0147] The luminous efficiency is obtained by testing and calculating with a Keithley 2400 high-precision digital source meter, an Ocean Optic USB2000+ spectrometer, and an LS-160 luminance meter.

[0148] The efficiency fluctuation of the optoelectronic device during turn-on / turn-off is the change in luminous efficiency when the optoelectronic device operates at 1000 nit and restarts after being turned off for 1 minute.

[0149] Table 1

[0150]

[0151]

[0152] It can be seen from Table 1 that:

[0153] It can be seen from Examples 1 to 3 and Comparative Example 1 that treating the electron transport layer with carbon dioxide gas can effectively improve the service life and luminous efficiency of the optoelectronic device, and reduce the efficiency fluctuation of the optoelectronic device. Among them, zinc oxide as the material of the electron transport layer has a better effect than barium oxide, and magnesium-doped zinc oxide has a better effect than zinc oxide;

[0154] It can be seen from Example 1, Examples 4 to 5 and Comparative Example 1 that within the purity range of the carbon dioxide gas provided in this application, when the purity of the carbon dioxide gas is appropriate, the service life of the optoelectronic device can be significantly extended. When the purity of the carbon dioxide gas is small or large, the luminous efficiency of the optoelectronic device can be significantly improved;

[0155] It can be seen from Example 1, Examples 6 to 7 and Comparative Example 1 that within the gas flow range of the carbon dioxide gas provided in the application, the performance of the optoelectronic device can be effectively improved. Compared with the optoelectronic device of Comparative Example 1, the luminous efficiency is significantly improved, the service life is extended, and the fluctuation of the luminous efficiency is reduced;

[0156] It can be seen from Example 1, Examples 8 to 9 and Comparative Example 1 that within the time range of the carbon dioxide gas treatment provided in the application, the optoelectronic devices of Example 1 and Examples 8 to 9 have high luminous efficiency, long service life, and a small range of luminous efficiency fluctuation and good stability;

[0157] As can be seen from Example 1, Examples 10 to 13 and Comparative Example 1, within the temperature range for carbon dioxide gas treatment provided in this application, compared with Comparative Example 1, the current efficiency, its fluctuation, and the service life of the optoelectronic device have been significantly improved; especially when the temperature is 50°C to 80°C, the stability of the optoelectronic device is relatively higher, and the service life has been significantly extended.

[0158] As can be seen from Example 1 and Comparative Examples 1 to 4, compared with treating the zinc oxide electron transport layer with solid carbon dioxide, liquid carbon dioxide, or a mixed gas of carbon dioxide and other reducing gases, water vapor, etc., treating with carbon dioxide gas in Example 1 results in a higher luminous efficiency, longer service life of the optoelectronic device, significantly reduced fluctuations in luminous efficiency, and improved stability of the optoelectronic device.

[0159] The above has introduced in detail the thin film, its preparation method, optoelectronic device, and display device provided in the embodiments of the present application. Specific examples are used herein to elaborate on the principles and implementation manners 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, based on the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for preparing a thin film, characterized in that, Comprising: Providing a base film, the material of the base film comprising inorganic nanoparticles and impurities, and the impurities comprising organic compounds; Flowing carbon dioxide gas over the surface of the base film to obtain a thin film.

2. The preparation method according to claim 1, wherein The flowing of the carbon dioxide gas over the surface of the base film is carried out under heating conditions, and the heating temperature is 10°C to 150°C; and / or The purity of the carbon dioxide gas is 99% to 100%; and / or The gas flow rate of the carbon dioxide gas is 5 L / min to 60 L / min; and / or The time for flowing the carbon dioxide gas over the surface of the base film is 10 min to 30 min; and / or The flowing of the carbon dioxide gas over the surface of the base film is carried out in an inert atmosphere, and the inert gas in the inert atmosphere comprises one or more of nitrogen, argon, helium, neon, krypton, and xenon.

3. The preparation method according to claim 1, wherein The inorganic nanoparticles comprise 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 comprises one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxides in the first doped metal oxide particles comprise one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the first doped metal oxide particles comprise one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA group semiconductor materials comprise one or more of ZnS, ZnSe, and CdS. The IIIA-VA group semiconductor materials comprise one or more of InP and GaP. The IB-IIIA-VIA group semiconductor materials comprise one or more of CuInS and CuGaS; and / or The average particle size of the inorganic nanoparticles is 2 nm to 15 nm; and / or The impurities further comprise inorganic bases; and / or The thickness of the base film is 40 nm to 60 nm.

4. The preparation method according to claim 1, characterized in that, The preparation method of the base film comprises: Providing an inorganic nanoparticle dispersion liquid, the inorganic nanoparticle dispersion liquid comprising inorganic nanoparticles and a solvent; Providing a substrate, and disposing the inorganic nanoparticle dispersion liquid on the substrate to obtain a base film.

5. The preparation method according to claim 4, wherein The solvent comprises one or more of benzene, carbon tetrachloride, diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, 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 In the inorganic nanoparticle dispersion liquid, the mass concentration of the inorganic nanoparticles is 25 mg / mL to 35 mg / mL.

6. The preparation method according to claim 4, characterized in that After the inorganic nanoparticle dispersion liquid is disposed on the substrate, annealing is further included; the temperature of the annealing is 75 °C to 85 °C, and the time is 5 min to 10 min.

7. A thin film, characterized in that, Prepared by the preparation method according to any one of claims 1 to 6.

8. The thin film according to claim 7, characterized in that, The material of the thin film includes inorganic nanoparticles and carbonate.

9. The thin film according to claim 8, wherein The carbonate includes one or more of zinc carbonate, barium carbonate, nickel carbonate, titanium carbonate, tin carbonate, tantalum carbonate, zirconium carbonate, cadmium carbonate, molybdenum carbonate, tungsten carbonate, copper carbonate, indium carbonate, gallium carbonate, barium carbonate, aluminum carbonate, magnesium carbonate, lithium carbonate, manganese carbonate, yttrium carbonate, lanthanum carbonate, cerium carbonate, and gadolinium carbonate.

10. An optoelectronic device, characterized in that, Comprising: An anode, a light-emitting layer, an electron functional layer, and a cathode which are sequentially stacked, wherein the electron functional layer includes a thin film prepared by the preparation method according to any one of claims 1 to 6, or includes a thin film according to any one of claims 7 to 9.

11. The optoelectronic device according to claim 10, wherein The materials of 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, 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, 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 materials of the light-emitting layer include 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 materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescence materials, TTA materials, TADF materials, polymers containing B-N covalent bonds, HLCT materials, Exciplex light-emitting materials, 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, HgZnSTe, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, 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, InAlPSb, CuInS2, CuInSe2, AgInS2, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, InP / ZnSe / ZnS, AMX3 and BMX3, where A is Cs + ions, 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+ or one or more of the following, X is a halogen anion selected from Cl - , Br - , I - or one or more of the following; B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2; and / or The optoelectronic device further includes a hole functional layer, and the hole functional layer is disposed between the anode and the light-emitting 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 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. The metal nitrides include p-type gallium nitride.; 12. A display device, characterized in that, An optoelectronic device including the optoelectronic device according to any one of claims 10 to 11.

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