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

Abstract

The embodiment of the invention relates to the field of display, in particular to a thin film and a preparation method thereof, a photoelectric device and a display device. Wherein the material of the thin film comprises an N-type semiconductor material and transition metal carbide. According to the technical scheme provided by the invention, the carrier transmission performance of the thin film can be 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] In the existing functional layer, a metal oxide layer can be set to improve the carrier transport performance. However, the stability of the metal oxide layer is poor, and the carrier transport performance needs to be further improved. Summary of the Invention

[0003] Based on this, the present application provides a thin film, a preparation method thereof, an optoelectronic device, and a display device.

[0004] To solve the above technical problems, the present application provides a thin film, and adopts the following technical solution:

[0005] A thin film, the material of the thin film includes an N-type semiconductor material and a transition metal carbide.

[0006] To solve the above technical problems, the present application also provides a preparation method of a thin film, and adopts the following technical solution:

[0007] A preparation method of a thin film, characterized by comprising:

[0008] Providing an N-type semiconductor material and a transition metal carbide;

[0009] Depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film.

[0010] To solve the above technical problems, the present application also provides an optoelectronic device, and adopts the following technical solution:

[0011] An optoelectronic device, comprising an anode, an electron transport layer, and a cathode which are sequentially stacked;

[0012] Wherein, the electron transport layer includes the thin film as described above, or a thin film prepared by using the preparation method of the thin film as described above.

[0013] To solve the above technical problems, an embodiment of the present application also provides a display device, and adopts the following technical solution:

[0014] A display device, comprising the optoelectronic device as described above.

[0015] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: By utilizing the photothermal effect characteristics of the transition metal carbide layer, the carrier transport performance of the thin film is improved. Description of the Drawings

[0016] To more clearly illustrate the solution of this application, the following will give a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 is a schematic structural diagram of a thin film of the present invention;

[0018] Figure 2 is a flowchart of a method for preparing a thin film of the present invention;

[0019] Figure 3 is a schematic structural diagram of an optoelectronic device of the present invention;

[0020] Reference numerals:

[0021] 100, thin film; 110, first sublayer; 120, second sublayer; 300, optoelectronic device; 310, anode; 320, electron transport layer; 330, cathode; 340, electron injection layer; 350, light-emitting layer; 360, hole injection layer; 370, hole transport layer. Detailed embodiments

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field of this application; the terms used in the description of the application in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and are not used to describe a specific order.

[0023] Referring to

[0024] Referring to Figure 1 , an embodiment of this application provides a thin film, and the material of the thin film 100 includes an N-type semiconductor material and a transition metal carbide.

[0025] In this embodiment, by utilizing the photothermal effect characteristics of transition metal carbides, a thermal island is formed in the thin film 100, so that the electron carriers passing through the thermal island can obtain higher energy, forming hot electron carriers, enhancing the kinetic energy of the electron carriers, making it easier for them to cross the energy band barrier and enter a state of higher energy levels, thereby increasing the density, mobility, and transport performance of the electron carriers.

[0026] Secondly, the temperature of the thermal island enhances the lattice vibration, reduces the local distortion of the lattice, thereby reducing the interaction between electron carriers and lattice defects or impurities, decreasing the scattering of electron carriers, and further enhancing the mobility and transport performance of the electron carriers.

[0027] In some embodiments, referring to Figure 1 , the thin film 100 includes a first sub-layer 110 and a second sub-layer 120 arranged in a stacked manner. The material of the first sub-layer 110 includes the N-type semiconductor material, and the material of the second sub-layer 120 includes the transition metal carbide. In this way, not only can the mobility and transport performance of electron carriers be enhanced by using transition metal carbides, but also since the Fermi level of the second sub-layer 120 is close to the valence band position of the first sub-layer 110, if there are excessive hole carriers in the first sub-layer 110, they can be captured by the second sub-layer 120 to avoid the further transport of excessive hole carriers on the thin film to form leakage current, thereby enhancing the electron carrier transport performance of the thin film.

[0028] Further, the thickness of the first sub-layer is 20 - 80 nm.

[0029] Optionally, the thickness of the first sub-layer is selected from any one or any range formed by any two of 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, and 80 nm.

[0030] Further, the thickness of the second sub-layer is 5 - 15 nm.

[0031] Optionally, the thickness of the second sub-layer is selected from any one or any range formed by any two of 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, and 15 nm.

[0032] In other embodiments, the thin film 100 has a single-layer structure. In this way, not only can the mobility and transport performance of electron carriers be enhanced by using transition metal carbides, but also the prepared thin film 100 can be made thinner and lighter.

[0033] Further, the thin film has a single-layer structure, and the thickness of the thin film is 30 - 80 nm.

[0034] Optionally, the thin film is a single-layer structure, and the thickness of the thin film is selected from any one or any range formed by any two of 30nm, 40nm, 50nm, 60nm, 70nm, and 80nm.

[0035] Furthermore, the mass of the transition metal carbide accounts for 90-96% of the total mass of the thin film 100 of the single-layer structure. Within this range, the photothermal effect characteristics of the transition metal carbide in the thin film 100 are ensured.

[0036] In some embodiments, the transition metal in the transition metal carbide includes at least one of VB group metal elements and VIB group metal elements.

[0037] In some embodiments, the material of the transition metal carbide is selected from at least one of tungsten carbide, vanadium carbide, molybdenum carbide, and tantalum carbide.

[0038] In some embodiments, at least part of the surface of the transition metal carbide is coated with a carbon coating layer. In this way, the transition metal carbide is coated with the carbon coating layer to prevent the transition metal carbide from being oxidized, thereby improving the use stability and lifespan of the thin film.

[0039] Understandably, the carbon coating layer can be a continuous and complete coating layer or an incomplete coating layer. Among them, "continuous and complete" means that the transition metal carbide located inside the carbon coating layer is completely coated by the carbon coating layer, so that the transition metal carbide is completely isolated from the outside world, thereby further preventing the transition metal carbide from being oxidized; "incomplete" means that the transition metal carbide located inside the carbon coating layer is not completely coated by the carbon coating layer, and at least part of the surface of the transition metal carbide can be in contact with the carbon coating layer.

[0040] Preferably, the carbon coating layer is a continuous and complete coating layer.

[0041] In some embodiments, the carbon coating layer includes a carbon material.

[0042] Optionally, the carbon material is selected from at least one of carbon, graphene oxide, carbon fiber, carbon nanotube, C60, graphite, and activated carbon.

[0043] In some embodiments, the N-type semiconductor material includes an inorganic N-type semiconductor material and / or an organic N-type semiconductor material. The inorganic N-type semiconductor material is selected from at least one of doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate, and the doping element is selected from at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, gadolinium; the organic N-type semiconductor material is selected from at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, hydroxyquinoline compounds, polythiophene compounds, perylene diimide compounds, fullerene compounds.

[0044] Referring to Figure 2 , an embodiment of the present application provides a method for preparing a thin film for preparing the thin film as described above; the method for preparing the thin film includes:

[0045] Step S21, providing an N-type semiconductor material and a transition metal carbide;

[0046] Step S22, depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film.

[0047] In this embodiment, by utilizing the photothermal effect characteristic of the transition metal carbide, a thermal island is formed on the thin film, so that the electron carriers passing through the thermal island can obtain higher energy, forming hot electron carriers, enhancing the kinetic energy of the electron carriers, making it easier for them to cross the energy band barrier and enter a higher energy level state, thereby increasing the density, mobility and transport performance of the electron carriers.

[0048] Secondly, the temperature of the thermal island will enhance the lattice vibration and reduce the local distortion of the lattice, thereby reducing the interaction between electron carriers and lattice defects or impurities, reducing the scattering of electron carriers, and further enhancing the mobility and transport performance of electron carriers.

[0049] In some embodiments, in the above step S22, the step of depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film specifically includes:

[0050] Step S22a1, providing a first solution containing the N-type semiconductor material.

[0051] In this step, the N-type semiconductor material is dissolved in a solvent to prepare a first solution.

[0052] Optionally, the solvent for dissolving the N-type semiconductor is selected from at least one of aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, halogenated hydrocarbon solvents, alcohol solvents, ether solvents, ester solvents, ketone solvents, diol derivative solvents, acetonitrile, and pyridine; the aromatic hydrocarbon solvents include at least one of benzene, toluene, and xylene; the aliphatic hydrocarbon solvents include at least one of pentane, hexane, and octane; the alicyclic hydrocarbon solvents include at least one of cyclohexane, cyclohexanone, and toluene cyclohexanone; the halogenated hydrocarbon solvents include at least one of chlorobenzene, dichlorobenzene, and dichloromethane; the alcohol solvents include at least one of methanol, ethanol, and isopropanol; the ether solvents include at least one of diethyl ether and propylene oxide; the ester solvents include at least one of methyl acetate, ethyl acetate, and propyl acetate; the ketone solvents include at least one of acetone, methyl butanone, and methyl isobutyl ketone; the diol derivative solvents include at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether.

[0053] Step S22a2, depositing the first solution to form a first sub-layer.

[0054] In this step, the first solution is disposed on the carrier surface by a solution method, and then through a desolvation process, the solute in the first solution is deposited on the carrier surface to form a first sub-layer.

[0055] Optionally, the solution method includes, but is not limited to, sol-gel method, printing method, inkjet printing method, spin coating method, coating method, etc.

[0056] Step S22a3, providing a second solution containing the transition metal carbide.

[0057] In this step, the transition metal carbide is dissolved in a solvent to prepare a second solution.

[0058] Optionally, the solvent for dissolving the transition metal carbide is selected from at least one of aromatic hydrocarbon solvents and ketone solvents; the aromatic hydrocarbon solvents include at least one of benzene, toluene, and xylene; the ketone solvents include at least one of acetone, methyl butanone, and methyl isobutyl ketone.

[0059] Step S22a4, depositing the second solution on the first sub-layer to form a second sub-layer, obtaining a thin film.

[0060] In this step, the second solution is disposed on the first sub-layer by a solution method, and then through a desolvation process, the solute in the second solution is deposited on the carrier surface to form a second sub-layer.

[0061] Optionally, the solution method includes, but is not limited to, sol-gel method, printing method, inkjet printing method, spin coating method, coating method, etc.

[0062] In some other embodiments, in step S22, the step of depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film specifically includes:

[0063] Step S22b1, providing a third solution containing the N-type semiconductor material and the transition metal carbide.

[0064] In this step, the N-type semiconductor material and the transition metal carbide are dissolved in a solvent to prepare a third solution.

[0065] Optionally, the solvent for dissolving the N-type semiconductor material and the transition metal carbide is selected from at least one of aromatic hydrocarbon solvents and ketone solvents; the aromatic hydrocarbon solvents include at least one of benzene, toluene, and xylene; the ketone solvents include at least one of acetone, methyl butanone, and methyl isobutyl ketone.

[0066] Step S22b2, depositing the third solution to obtain a thin film.

[0067] In this step, the third solution is disposed on a carrier surface by a solution method, and then through a desolvation process, the solute in the third solution is deposited on the carrier surface to form a thin film.

[0068] Optionally, the solution method includes but is not limited to sol-gel method, printing method, inkjet printing method, spin coating method, coating method, etc.

[0069] In some embodiments, before the step S21 of providing the N-type semiconductor material and the transition metal carbide, it further includes:

[0070] Step S211, providing a carbon precursor and a second metal precursor.

[0071] In some embodiments, the material of the carbon precursor includes at least one of dicyandiamide, sucrose, and glucose.

[0072] In some embodiments, the material of the first metal precursor includes at least one of ammonium metatungstate, ammonium molybdate, ammonium vanadate, and tantalum chloride.

[0073] Step S212, preparing a transition metal carbide using the carbon precursor and the second metal precursor.

[0074] In some embodiments, the mass ratio of the carbon precursor to the second metal precursor is (0.3 - 5):1.

[0075] Optionally, the mass ratio of the carbon precursor to the second metal precursor is selected from any one of 0.3:1, 0.7:1, 1:1, 1.3:1, 1.7:1, 2:1, 2.3:1, 2.7:1, 3:1, 3.3:1, 3.7:1, 4:1, 4.3:1, 4.7:1, 5:1 or the range formed by any two of them.

[0076] In some embodiments, in the above step S212, the step of preparing the transition metal carbide using the carbon precursor and the second metal precursor includes:

[0077] Step S2121, mixing the carbon precursor and the second metal precursor to obtain a mixed precursor.

[0078] In this step, the carbon compound precursor and the first metal compound precursor are ground into granular or powdery form and then subjected to a mixing reaction to obtain a mixed precursor.

[0079] Step S2122, performing a carbonization treatment on the mixed precursor to obtain a transition metal carbide coated with a carbon coating layer on its surface.

[0080] In this step, the transition metal carbide is coated with a carbon coating layer to prevent the transition metal carbide from being oxidized, thereby improving the use stability and lifespan of the thin film.

[0081] In some embodiments, the carbonization treatment is carried out in an inert atmosphere to prevent the reactants from being oxidized during the carbonization treatment.

[0082] Optionally, the inert atmosphere includes at least one of nitrogen, argon, helium, neon, krypton, and xenon.

[0083] In some embodiments, the flow rate of the nitrogen is 2 - 5 mL / min.

[0084] Optionally, the flow rate of the nitrogen is selected from any one of 2 mL / min, 3 mL / min, 4 mL / min, 5 mL / min or the range formed by any two of them.

[0085] In some embodiments, the carbonization treatment includes a first heat treatment and a second heat treatment; wherein, the first heat treatment is used to preheat the mixed precursor to a preset temperature to facilitate the subsequent second heat carbonization treatment, so that the mixed precursor is fully carbonized; the second heat treatment is used to fully carbonize the mixed precursor after the first heat treatment.

[0086] In some embodiments, the temperature of the first heat treatment is 350 - 550 °C.

[0087] Optionally, the temperature of the first heat treatment is in the range formed by any one or any two of 350°C, 400°C, 450°C, 500°C, and 550°C.

[0088] In some embodiments, the time of the first heat treatment is 20 - 80 min.

[0089] Optionally, the time of the first heat treatment is selected from the range formed by any one or any two of 20 min, 40 min, 60 min, and 80 min.

[0090] In some embodiments, the temperature of the second heat treatment is 600 - 900°C.

[0091] Optionally, the temperature of the first heat treatment is in the range formed by any one or any two of 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, and 900°C.

[0092] In some embodiments, the time of the second heat treatment is 2 - 6 h.

[0093] Optionally, the time of the second heat treatment is selected from the range formed by any one or any two of 2 h, 3 h, 4 h, 5 h, and 6 h.

[0094] Referring to Figure 3 , an embodiment of the present application provides an optoelectronic device, including an anode 310, an electron transport layer 320, and a cathode 330 that are sequentially stacked;

[0095] Wherein, the electron transport layer 320 includes the thin film as described above, or a thin film prepared by using the preparation method of the thin film as described above.

[0096] In this embodiment, when the thin film 100 includes a first sub - layer 110 and a second sub - layer 120, the second sub - layer 120 is disposed between the first sub - layer 110 and the cathode 330. When the thin film has a single - layer structure, the cathode 330 is stacked on the thin film 100.

[0097] In the electron transport layer 320 of the optoelectronic device 300, by utilizing the photothermal effect characteristics of transition metal carbides, heat islands are formed in the thin film, so that the electron carriers passing through the heat islands can obtain higher energy, forming hot electron carriers, enhancing the kinetic energy of the electron carriers, making it easier for them to cross the energy band barrier and enter a higher energy level state, thereby increasing the density, mobility, and transport performance of the electron carriers.

[0098] Secondly, the temperature of the heat islands enhances the lattice vibration, reduces the local lattice distortion, thereby reducing the interaction between electron carriers and lattice defects or impurities, reducing the scattering of electron carriers, and further enhancing the mobility and transport performance of the electron carriers.

[0099] In some embodiments, the optoelectronic device 300 further includes an electron injection layer 340 disposed between the electron transport layer 320 and the cathode 330.

[0100] In this embodiment, when the thin film 100 includes a first sub-layer 110 and a second sub-layer 120, the electron injection layer 340 is disposed between the second sub-layer 120 and the cathode 330. When the thin film 100 has a single-layer structure, the electron injection layer 340 is disposed between the thin film 100 and the cathode 330.

[0101] Furthermore, the material of the electron injection layer 340 includes inorganic materials and / or organic materials; the inorganic materials include one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, zinc stannide, indium phosphide, gallium phosphide, barium titanate, transition metal sulfides, and the doped elements include at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, gadolinium; the organic materials include at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, hydroxyquinoline compounds, polythiophene compounds, perylene diimide compounds, fullerene compounds.

[0102] Preferably, the material of the electron injection layer 340 is a transition metal sulfide. By utilizing the good conductivity of the transition metal sulfide, the conductivity of the electron injection layer 340 is improved, thereby enhancing the electron injection performance of the electron injection layer 340.

[0103] Secondly, when the thin film 100 includes a first sub-layer 110 and a second sub-layer 120 arranged in a stacked manner, since the valence band (6.17 eV) of the electron injection layer 340 formed by the transition metal sulfide is close to the Fermi level (5.52 eV) of the second sub-layer 120 formed by the transition metal carbide, excessive hole carriers are adsorbed and recombined by the hot electron carriers on the second sub-layer 120 due to electrostatic interaction, so as to prevent the hole carriers from transferring towards the cathode, thereby reducing the leakage current of the optoelectronic device 300 and improving the use stability of the optoelectronic device 300.

[0104] In some embodiments, the transition metal in the transition metal sulfide includes at least one of Group IIIA metal elements, Group IIB metal elements, Group IB metal elements, and Group VIII metal elements.

[0105] In some embodiments, the transition metal sulfide is selected from at least one of CuInS2, CuGaS2, CdS, ZnS, MoS2, WS2, CuS, ZnIn2S4, ZnCoS2, ZnFeS2, CuZnS2, and CoFeS2.

[0106] In some embodiments, the transition metal sulfide is doped with a metal material.

[0107] In this embodiment, by virtue of the good electrical conductivity of the metal material, the electrical conductivity of the electron injection layer 340 is further improved, thereby further enhancing the electron injection performance of the electron injection layer 340; moreover, after the transition metal sulfide is doped with the metal material, sulfur vacancy defects are formed in the transition metal sulfide to capture the incoming hole carriers, thereby suppressing the recombination of hole carriers in the electron injection layer 340. Thus, the stability of the thin film 100 and the electron carrier injection performance are improved.

[0108] Secondly, the metal material on the electron injection layer 340 can, on the one hand, reduce the interfacial barrier between the electron injection layer 340 and the cathode 330, further improving the transport efficiency of electron carriers, and on the other hand, enhance the stability of the composite connection between the electron injection layer 340 and the cathode 330; furthermore, since the transition metal sulfide is formed by stacking multiple layers of atoms and the outermost layer is an S atom, it will not oxidize the cathode, thereby improving the service stability and lifespan of the optoelectronic device 300.

[0109] In some embodiments, the metal material includes at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg.

[0110] In some embodiments, the doping amount of the metal material is 1-3 wt%.

[0111] Optionally, the doping amount of the metal material is any one or any range formed by any two of 1 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.2 wt%, 2.4 wt%, 2.6 wt%, 2.8 wt%, 3 wt%, 3.2 wt%, 3.4 wt%, 3.6 wt%, 3.8 wt%, 4 wt%, 4.2 wt%, 4.4 wt%, 4.6 wt%, 4.8 wt%, and 5 wt%.

[0112] The preparation method for preparing the electron injection layer 340 using the transition metal sulfide will be clearly and completely described below:

[0113] Step S31, provide a fourth solution containing a transition metal sulfide;

[0114] Step S32: Deposit the fourth solution on the electron transport layer 320 to obtain the electron injection layer 340.

[0115] In this step, the fourth solution is disposed on the electron transport layer 320 by solution method, and then through desolvation treatment, the solute in the fourth solution is deposited on the bearing surface to form the electron injection layer 340.

[0116] Optionally, the solution method includes but is not limited to sol-gel method, printing method, inkjet printing method, spin coating method, coating method, etc.

[0117] In step S31:

[0118] Further, the step of providing the fourth solution containing transition metal sulfide includes:

[0119] Step S311: Provide a sulfur precursor and a second metal precursor;

[0120] Step S312: Mix the sulfur precursor and the second metal precursor to obtain transition metal sulfide.

[0121] Further, the sulfur precursor is selected from at least one of thioacetamide, thiourea, and sodium sulfide.

[0122] Further, the mass ratio of the sulfur precursor to the second metal precursor is (0.7:6):(2 - 13).

[0123] Optionally, the mass ratio of the sulfur precursor to the second metal precursor is selected from any one or any range formed by any two of 0.7:2, 0.7:4, 0.7:6, 0.7:8, 0.7:10, 0.7:12, 0.7:13, 1:2, 1:4, 1:6, 1:8, 1:10, 1:12, 1:13, 1.5:2, 1.5:4, 1.5:6, 1.5:8, 1.5:10, 1.5:12, 1.5:13, 2:2, 2:4, 2:6, 2:8, 2:10, 2:12, 2:13.

[0124] Further, the second metal precursor includes a first sub-metal precursor and a second sub-metal precursor.

[0125] Optionally, the first sub-metal precursor is selected from at least one of zinc chloride, zinc acetate, zinc acetate, cobalt nitrate, and copper nitrate.

[0126] Optionally, the second sub-metal precursor is selected from at least one of indium chloride, indium oleate, ferric trichloride, and ferric nitrate.

[0127] Further, the mass ratio of the first sub-metal precursor to the second sub-metal precursor is (1 to 6):(1 to 7).

[0128] Optionally, the mass ratio of the first sub-metal precursor to the second sub-metal precursor is selected from any one or any range formed by any two of 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 3:1, 3:2, 3:3, 3:4, 3:5, 3:6, 3:7, 5:1, 5:2, 5:3, 5:4, 5:5, 5:6, 5:7, 6:1, 6:2, 6:3, 6:4, 6:5, 6:6, 6:7.

[0129] Further, in the above step S312, the sulfur precursor and the second metal precursor are added to an alcohol solution for dissolution, then after stirring evenly, it is left to stand and cool to room temperature, and finally dried to form a transition metal sulfide.

[0130] Further, before the step of mixing the sulfur precursor and the second metal precursor in the above step S312, it further includes:

[0131] Step S3121, providing a doped metal precursor.

[0132] Step S3122, mixing the doped metal precursor, the sulfide precursor and the second metal compound precursor to obtain a transition metal sulfide doped with a metal material;

[0133] Step S3123, preparing a fourth solution containing the transition metal sulfide.

[0134] Further, the doped metal precursor is selected from at least one of aluminum butoxide, aluminum phosphate, aluminum nitrate, silver nitrate, silver acetate, and silver acetate.

[0135] Further, in the above step S312, the step of mixing the sulfur precursor and the second metal precursor to obtain a transition metal sulfide includes:

[0136] Further, the mass ratio of the doped metal precursor, the sulfur precursor and the first metal precursor is 1:(0.7:6):(2 to 13).

[0137] Optionally, the mass ratio of the doped metal precursor, the sulfur precursor, and the first metal precursor is selected from any one or any range formed by any two of 1:0.7:2, 1:0.7:4, 1:0.7:6, 1:0.7:8, 1:0.7:10, 1:0.7:12, 1:0.7:13, 1:1:2, 1:1:4, 1:1:6, 1:1:8, 1:1:10, 1:1:12, 1:1:13, 1:1.5:2, 1:1.5:4, 1:1.5:6, 1:1.5:8, 1:1.5:10, 1:1.5:12, 1:1.5:13, 1:2:2, 1:2:4, 1:2:6, 1:2:8, 1:2:10, 1:2:12, 1:2:13.

[0138] Further, the transition metal sulfide is dissolved in a solvent to prepare a fourth solution.

[0139] Optionally, the solvent for dissolving the transition metal sulfide is selected from at least one of aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, halogenated hydrocarbon solvents, alcohol solvents, ether solvents, ester solvents, ketone solvents, diol derivative solvents, acetonitrile, and pyridine; the aromatic hydrocarbon solvents include at least one of benzene, toluene, and xylene; the aliphatic hydrocarbon solvents include at least one of pentane, hexane, and octane; the alicyclic hydrocarbon solvents include at least one of cyclohexane, cyclohexanone, and toluene cyclohexanone; the halogenated hydrocarbon solvents include at least one of chlorobenzene, dichlorobenzene, and dichloromethane; the alcohol solvents include at least one of methanol, ethanol, and isopropanol; the ether solvents include at least one of diethyl ether and propylene oxide; the ester solvents include at least one of methyl acetate, ethyl acetate, and propyl acetate; the ketone solvents include at least one of acetone, methyl butanone, and methyl isobutyl ketone; the diol derivative solvents include at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether.

[0140] In some embodiments, the materials of the anode 310 and the cathode 330 independently include at least one of a metal material, a carbon material, and a metal oxide. The metal material 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 doped or undoped metal oxide. The doped metal oxide includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or includes a composite electrode in which a doped or undoped transparent metal oxide sandwiches a metal. 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.

[0141] In some embodiments, the optoelectronic device 300 further includes a light-emitting layer 340 disposed between the anode 310 and the electron transport layer 320; the light-emitting layer 340 is a quantum dot light-emitting layer or an organic light-emitting layer; the material of the quantum dot light-emitting layer includes at least one of single-structure quantum dots and core-shell structure quantum dots, and the materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are each independently selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The core-shell structure quantum dots include one or more layers. Among them, the II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2;The materials of the organic light-emitting layer 320 include at least one of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine-C2,N]iridium(III), 4,4',4''-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine-C2,N]iridium, diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, and DBP fluorescent materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives.

[0142] In some embodiments, the optoelectronic device 300 further includes a hole injection layer 350 and / or a hole transport layer 360 disposed between the anode 310 and the light-emitting layer 340. The hole injection layer 350 and the hole transport layer 360 each independently include at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, C60, copper polycarbonate, and molybdenum trioxide.

[0143] An embodiment of the present application provides a display device including the optoelectronic device as described above.

[0144] In this embodiment, the display device includes a plurality of optoelectronic devices, and the optoelectronic device has an electron transport layer containing a thin film; in the thin film, using the photothermal effect characteristics of transition metal carbides, heat islands are formed in the thin film, so that the electron carriers passing through the heat islands can obtain higher energy, forming hot electron carriers, enhancing the kinetic energy of the electron carriers, making it easier for them to cross the energy band barrier and enter a higher energy level state, thereby increasing the density, mobility, and transport performance of the electron carriers.

[0145] Secondly, the temperature of the heat island will enhance the lattice vibration and reduce the local distortion of the lattice, thereby reducing the interaction between electron carriers and lattice defects or impurities, reducing the scattering of electron carriers, and further enhancing the mobility and transport performance of the electron carriers.

[0146] The technical solutions and technical effects of the present application are described in detail below through specific examples and comparative examples. The following examples are only partial examples of the present application and do not specifically limit the present application.

[0147] Thin film Example 1:

[0148] Step 1: Provide a substrate.

[0149] Step 2: Print a first solution containing ZnO on the substrate. After solvent removal treatment, a first sub-layer with a thickness of 30 nm is formed.

[0150] Step 3: Mix 0.1 g of ammonium metatungstate and 0.03 g of dicyandiamide and grind for 20 min to obtain tungsten carbide. Dissolve the tungsten carbide in an ethanol solvent to obtain a second solution; print 6 drops of the second solution on the first sub-layer. After solvent removal treatment, a second sub-layer with a thickness of 10 nm is formed to obtain a thin film; wherein, the mass ratio of dicyandiamide to ammonium metatungstate is 0.3:1.

[0151] Thin film Example 2:

[0152] The difference from Thin film Example 1 is that: in Step 3 of this example, the mass of dicyandiamide is changed to 0.2 g; correspondingly, the mass ratio of ammonium metatungstate to dicyandiamide is 1:2.

[0153] Thin film Example 3:

[0154] The difference from Thin film Example 1 is that: in Step 3 of this example, the mass of dicyandiamide is changed to 0.5 g; correspondingly, the mass ratio of ammonium metatungstate to dicyandiamide is 1:5.

[0155] Thin film Example 4:

[0156] The difference from Thin film Example 1 is that: in Step 3 of this example, ammonium metatungstate is changed to ammonium molybdate; correspondingly, the prepared transition metal carbide is molybdenum carbide.

[0157] Thin film Example 5:

[0158] The difference from Thin film Example 1 is that: in Step 3 of this example, ammonium metatungstate is changed to ammonium metavanadate; correspondingly, the prepared transition metal carbide is vanadium carbide.

[0159] Thin film Example 6:

[0160] The difference from Thin film Example 1 is that: in Step 3 of this example, before the step of dissolving the tungsten carbide in the ethanol solvent, the prepared tungsten carbide is placed in a muffle furnace and, under a nitrogen atmosphere with a flow rate of 2.5 mL / min, first heated to 400 °C and held for 30 min, and then heated to 800 °C and held for 5 h so that the surface of the tungsten carbide is coated with a carbon coating; correspondingly, the tungsten carbide with a carbon coating on the surface is dissolved in an ethanol solvent to obtain a second solution.

[0161] Thin film Example 7:

[0162] It is different from Film Example 1 in that: Step two is omitted; in Step three of this example, in the step of dissolving tungsten carbide in an ethanol solvent, ZnO is further added to the ethanol solvent to obtain a third solution; correspondingly, 8 drops of the third solution are printed on the substrate, and after solvent removal treatment, a 30-nm-thick single-layer structure film is formed; wherein, the mass ratio of ammonium metatungstate to dicyandiamide is 1:0.3.

[0163] Film Comparative Example 1:

[0164] It is different from Film Example 1 in that: This comparative example omits Step three; correspondingly, the first sub-layer obtained in Step two is used as the film.

[0165] Experimental test analysis: The films prepared in Film Examples 1 to 7 and Film Comparative Example 1 are used to prepare single-electron devices, and the I-V curves of the single-electron devices prepared in Film Examples 1 to 7 and Film Comparative Example 1 are respectively tested by Keithley 2400. The test results are shown in Table 1.

[0166] Table 1

[0167]

[0168]

[0169] Referring to Table 1, from Film Examples 1 to 5, Film Example 7 and Film Comparative Example 1, it can be seen that the present invention utilizes the photothermal effect characteristics of tungsten carbide to form a heat island on the film, so that the electron carriers passing through the heat island form hot carriers, increasing the density, mobility and transport performance of electron carriers; and the temperature of the heat island will enhance the lattice vibration, reducing the interaction between electron carriers and lattice defects or impurities, thereby further improving the mobility and transport performance of carriers. In this way, at a driving voltage of 4V, the currents of the single-electron devices prepared in Film Examples 1 to 5 of the present invention are all greater than those of the single-electron devices prepared in Film Comparative Example 1.

[0170] Continuing to refer to Table 1, from Film Examples 1 and 6 and Film Comparative Example 1, it can be seen that on the basis of Film Example 1 of the present invention, the surface of tungsten carbide is coated with a carbon coating layer to prevent tungsten carbide from being oxidized by the atmosphere, thereby ensuring the conductivity of the second sub-layer prepared from tungsten carbide. In this way, at a driving voltage of 4V, compared with the single-electron devices prepared in Film Example 1 and Film Comparative Example 1 of the present invention respectively, the current of the single-electron device prepared in Film Example 6 of the present invention is greater.

[0171] Optoelectronic Device Example 1:

[0172] Step one, provide an ITO substrate as the anode.

[0173] Step 2: By means of an inkjet printing process, PEDOT / PSS is printed on the anode to obtain a hole injection layer with a thickness of 40 nm.

[0174] Step 3: By means of an inkjet printing process, poly-TPD is printed on the hole injection layer to obtain a hole transport layer with a thickness of 30 nm.

[0175] Step 4: A red light quantum dot layer with a thickness of 30 nm is prepared on the hole transport layer.

[0176] Step 5: Using the method of Film Example 1, a film is prepared on the red light quantum dot layer to obtain an electron transport layer.

[0177] Step 6: Al is evaporated on the electron transport layer through an evaporation process to obtain a cathode with a thickness of 70 nm, thereby obtaining an optoelectronic device.

[0178] Optoelectronic Device Examples 2 to 7:

[0179] The difference from Optoelectronic Device Example 1 is that: in Step 5 of Optoelectronic Device Example n, the film is prepared by using the method of Step 3 in Film Example n, where n is any one of 2 to 7.

[0180] Optoelectronic Device Example 8:

[0181] The difference from Optoelectronic Device Example 1 is that: between Step 5 and Step 6 of this example, further included are: adding 120 mg of zinc chloride, 120 mg of indium chloride, and 84 mg of thioacetamide to 20 mL of methanol, stirring for 1 h, then heating to 120 °C and magnetically stirring for 2 h, after cooling to room temperature, washing and drying, the prepared transition metal sulfide is ZnIn2S4, and finally ZnIn2S4 is dissolved in an ethanol solvent to prepare a fourth solution with a concentration of 8 mg / mL, and 8 drops are printed on the electron transport layer to obtain an electron injection layer with a thickness of 20 nm;

[0182] Correspondingly, in Step 6 of this example, Al is evaporated on the electron injection layer through an evaporation process.

[0183] Optoelectronic Device Example 9:

[0184] The difference from Optoelectronic Device Example 8 is that: between Step 5 and Step 6 of this example, 120 mg of aluminum n-butoxide is further added to 20 mL of methanol; correspondingly, the prepared ZnIn2S4 is doped with Al atoms; wherein, the doping amount of Al atoms is 3 wt%, and the mass ratio of aluminum n-butoxide, zinc chloride, indium chloride, and thioacetamide is 1:1:1:0.7.

[0185] Optoelectronic Device Example 10:

[0186] The difference from Example 9 of the optoelectronic device is as follows: between Step 5 and Step 6 of this example, the mass of aluminum butoxide is changed to 80 mg; correspondingly, the doping amount of Al atoms is 2.1 wt%, and the mass ratio of aluminum butoxide, zinc chloride, indium chloride, and thioacetamide is 1:1.5:1.5:1.05.

[0187] Optoelectronic device Example 11:

[0188] The difference from Example 9 of the optoelectronic device is as follows: between Step 5 and Step 6 of this example, the mass of aluminum butoxide is changed to 40 mg; correspondingly, the doping amount of Al atoms is 1.2 wt%, and the mass ratio of aluminum butoxide, zinc chloride, indium chloride, and thioacetamide is 1:3:3:2.1.

[0189] Optoelectronic device Comparative Example 1:

[0190] The difference from Example 1 of the optoelectronic device is as follows: in Step 5 of this comparative example, the thin film is prepared by the method of Step 3 in Thin Film Comparative Example 1.

[0191] Optoelectronic device Comparative Example 2:

[0192] The difference from Optoelectronic device Comparative Example 1 is as follows: between Step 5 and Step 6 of this example, it further includes; depositing LiF on the first sublayer to obtain an electron injection layer with a thickness of 20 nm;

[0193] Correspondingly, in Step 6 of this example, Al is deposited on the electron injection layer through a deposition process.

[0194] Experimental test and analysis: The external quantum efficiency (EQE) and lifetime lt95@1000nit of the optoelectronic devices prepared from Optoelectronic device Examples 1 to 11 and Optoelectronic device Comparative Examples 1 and 2 are respectively tested by an IVL test system, and the test results are shown in Table 2.

[0195] Table 2

[0196]

[0197]

[0198] Referring to Table 2, from Examples 1 to 5, Example 7 of optoelectronic devices, and Comparative Example 1 of optoelectronic devices, it can be seen that the present invention utilizes the photothermal effect characteristics of tungsten carbide to form heat islands in the thin film, so that the electron carriers passing through the heat islands form hot carriers, increasing the density, mobility, and transport performance of electron carriers; moreover, the temperature of the heat islands enhances lattice vibration, thereby reducing the interaction between electron carriers and lattice defects or impurities, further improving the mobility and transport performance of electron carriers, and further enhancing the service stability of the device. Thus, compared with Comparative Example 1 of optoelectronic devices, LT95@1000nit and EQE of Examples 1 to 5 and 7 of the optoelectronic devices of the present invention are larger.

[0199] Continuing to refer to Table 2, from Example 1 and Example 6 of optoelectronic devices, and Comparative Example 1 of optoelectronic devices, it can be seen that on the basis of Example 1 of optoelectronic devices, the surface of tungsten carbide is coated with a carbon coating layer to prevent tungsten carbide from being oxidized by the atmosphere, thereby ensuring the conductivity and service stability of the second sublayer made of tungsten carbide, and prolonging the service life of the optoelectronic device. Thus, compared with Example 1 of optoelectronic devices and Comparative Example 1 of optoelectronic devices, LT95@1000nit and EQE of Example 6 of the optoelectronic devices of the present invention are larger.

[0200] Continuing to refer to Table 2, from Example 1 and Example 8 of optoelectronic devices, and Comparative Example 2 of optoelectronic devices, it can be seen that on the basis of Example 1 of optoelectronic devices, an electron injection layer is prepared on the second sublayer using a fourth solution containing transition metal sulfide to utilize the good conductivity of transition metal sulfide to improve the conductivity of the electron injection layer, thereby enhancing the electron injection performance; moreover, since the valence band of the electron injection layer formed by transition metal sulfide is close to the Fermi level position of the second sublayer formed by transition metal carbide, the hot electron carriers on the second sublayer can adsorb hole carriers through electrostatic interaction for recombination, inhibiting the hole carriers from entering the electron injection layer, thereby further enhancing the stability of the device. Thus, compared with Example 1 of optoelectronic devices and Comparative Example 2 of optoelectronic devices, LT95@1000nit and EQE of Example 8 of the optoelectronic devices of the present invention are larger.

[0201] Continuing to refer to Table 2, from Example 1 and Examples 9 to 11 of optoelectronic devices, it can be seen that on the basis of Example 8 of optoelectronic devices, the transition metal sulfide is doped with a metal material to further improve the electron injection performance of the electron injection layer, thereby further enhancing the electron injection performance; moreover, after the transition metal sulfide is doped with a metal material, sulfur vacancy defects are formed in the transition metal sulfide to capture the incoming hole carriers, thereby inhibiting the recombination of hole carriers in the electron injection layer, and further enhancing the device stability. Thus, compared with Example 1 of optoelectronic devices, LT95@1000nit and EQE of Examples 9 to 11 of the optoelectronic devices of the present invention are larger.

[0202] Obviously, the embodiments described above are only a part of the embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are shown in the accompanying drawings, but do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments or equivalently replace some of the technical features. Any equivalent structure made by using the content of the specification and drawings of the present application, directly or indirectly applied in other related technical fields, is similarly within the scope of patent protection of the present application.

Claims

1. A film, characterized in that, The materials of the thin film include an N-type semiconductor material and a transition metal carbide.

2. The thin film according to claim 1, characterized in that, The materials of the thin film consist of the N-type semiconductor material and the transition metal carbide; and / or, The thin film includes a first sub-layer and a second sub-layer arranged in a stacked manner. The material of the first sub-layer includes the N-type semiconductor material, and the material of the second sub-layer includes the transition metal carbide; or, the thin film is a single-layer structure, and the mass of the transition metal carbide accounts for 90-96% of the total mass of the thin film.

3. The thin film according to claim 2, characterized in that, The thickness of the first sub-layer is 20-80 nm; and / or, The thickness of the second sub-layer is 5-15 nm; and / or, The thin film is a single-layer structure, and the thickness of the thin film is 30-80 nm.

4. The thin film according to any one of claims 1 to 3, characterized in that, The transition metal in the transition metal carbide includes at least one of VB group metal elements and VIB group metal elements; and / or, The surface of the transition metal carbide is coated with a carbon coating layer; and / or, The N-type semiconductor material includes an inorganic N-type semiconductor material and an organic N-type semiconductor material; the inorganic N-type semiconductor material includes one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanate oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate, and the doping elements include at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, gadolinium; the organic N-type semiconductor material includes at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, hydroxyquinoline compounds, polythiophene compounds, perylene diimide compounds, fullerene compounds.

5. The thin film according to claim 4, wherein , The transition metal carbide is selected from at least one of tungsten carbide, vanadium carbide, molybdenum carbide, tantalum carbide; and / or, The material of the carbon coating layer includes a carbon material; the carbon material includes at least one of carbon, graphene oxide, carbon fiber, carbon nanotube, C60, graphite, activated carbon.

6. A method for preparing a thin film, characterized in that, Including: Providing an N-type semiconductor material and a transition metal carbide; Depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film.

7. The method for preparing the thin film according to claim 6, wherein The step of depositing the N-type semiconductor material and the transition metal carbide to obtain a thin film specifically includes: Providing a first solution containing the N-type semiconductor material; Depositing the first solution to form a first sub-layer; Providing a second solution containing the transition metal carbide; Depositing the second solution on the first sub-layer to form a second sub-layer to obtain a thin film; or, Providing a third solution containing the N-type semiconductor material and the transition metal carbide, and depositing the third solution to obtain a thin film.

8. The method for preparing the thin film according to claim 6 or 7, characterized in that, Before the step of providing the N-type semiconductor material and the transition metal carbide, it further includes: Providing a carbon precursor and a first metal precursor; Preparing a transition metal carbide using the carbon precursor and the first metal precursor.

9. The method for preparing the thin film according to claim 8, characterized in that, The step of preparing a transition metal carbide using the carbon precursor and the first metal precursor includes: Mix the carbon precursor and the first metal precursor to obtain a mixed precursor; Carry out carbonization treatment on the mixed precursor to obtain a transition metal carbide with a carbon coating layer on its surface.

10. The method for preparing a thin film according to claim 9, characterized in that, The mass ratio of the carbon precursor to the first metal precursor is (0.3 - 5):1; and / or, The material of the carbon precursor includes at least one of dicyandiamide, sucrose, and glucose; and / or, The material of the first metal precursor includes at least one of ammonium metatungstate, ammonium molybdate, ammonium vanadate, and tantalum chloride.

11. An optoelectronic device, characterized in that, It includes an anode, an electron transport layer, and a cathode which are stacked; Wherein, the electron transport layer includes the thin film as described in any one of claims 1 to 5, or a thin film prepared by using the preparation method of the thin film as described in any one of claims 6 to 10.

12. The optoelectronic device according to claim 11, wherein, The optoelectronic device further includes an electron injection layer, the electron injection layer is disposed between the electron transport layer and the cathode, and the material of the electron injection layer includes an inorganic material and / or an organic material; the inorganic material includes one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanate oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, zinc stannide, indium phosphide, gallium phosphide, barium titanate, transition metal sulfides, and the doped elements include at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium; the organic material includes at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, hydroxyquinoline compounds, polythiophene compounds, perylene diimide compounds, and fullerene compounds; and / or, The materials of the anode and the cathode independently include at least one of a metal material, a carbon material, and a metal oxide respectively. The metal material 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 doped or undoped metal oxides, the doped metal oxides include one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or a composite electrode including a metal sandwiched between doped or undoped transparent metal oxides, 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 optoelectronic device further includes a light-emitting layer disposed between the anode and the electron transport layer; the light-emitting layer is a quantum dot light-emitting layer or an organic light-emitting layer; the material of the quantum dot light-emitting layer includes at least one of a single-structure quantum dot and a core-shell structure quantum dot, the material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell material of the core-shell structure quantum dot are each independently selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds, the core-shell structure quantum dot includes one or more layers, wherein, the II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2;The materials of the organic light-emitting layer include at least one of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, tris[2-(p-tolyl)pyridine-C2,N]iridium(III), 4,4',4''-tris(carbazol-9-yl)triphenylamine, tris[2-(p-tolyl)pyridine-C2,N]iridium, diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, and DBP fluorescent materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives; and / or; The optoelectronic device further includes a hole injection layer and / or a hole transport layer disposed between the anode and the light-emitting layer, and the hole injection layer and the hole transport layer independently include at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxide, transition metal sulfide, transition metal stannide, doped graphene, undoped graphene, C60, copper polycarbonate, molybdenum trioxide.

13. The optoelectronic device according to claim 12, wherein, The transition metal in the transition metal sulfide includes at least one of Group IIIA metal elements, Group IIB metal elements, Group IB metal elements, and Group VIII metal elements; and / or, The transition metal sulfide is selected from at least one of CuInS2, CuGaS2, CdS, ZnS, MoS2, WS2, CuS, ZnIn2S4, ZnCoS2, ZnFeS2, CuZnS2, CoFeS2; and / or, The transition metal sulfide is doped with a metal material; the metal material includes at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg, and / or the doping amount of the metal material is 1 to 3 wt%.

14. A display device, characterized in that, An optoelectronic device according to any one of claims 11 to 13.

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