Hydrogenated zinc oxide nanomaterial, preparation method thereof, film and photoelectric device

Abstract

The present application discloses a hydrogenated zinc oxide nanomaterial, a preparation method thereof, a thin film, and a photoelectric device. The hydrogenated zinc oxide nanomaterial includes hydrogenated zinc oxide nanoparticles. The hydrogenated zinc oxide nanoparticles are obtained by partially reducing zinc oxide nanoparticles, that is, introducing hydrogen atoms into the zinc oxide nanoparticles. The hydrogen atoms can be used as a passivating agent to passivate surface defects of the zinc oxide nanoparticles, thereby inhibiting the formation of oxygen defects, thereby making the fluorescence intensity of the defect luminescence peak of the hydrogenated zinc oxide nanoparticles in the wavelength range of 500 nanometers to 600 nanometers at least 17% weaker than the fluorescence intensity of the defect luminescence peak of the zinc oxide nanoparticles at the same position. The hydrogenated zinc oxide nanomaterial can be used to prepare photoelectric devices, for example, as an electron transport layer of a quantum dot light-emitting device, which is beneficial to increasing the concentration of effective carriers and the conductivity, thereby improving the electron-hole recombination efficiency, and thus improving the luminescence performance and luminescence stability of the photoelectric device.

Description

Technical Field

[0001] The present application relates to the field of materials, and in particular to a hydrogenated zinc oxide nanomaterial, a preparation method thereof, a thin film and a photoelectric device. Background Art

[0002] Quantum dots (QDs) are a new generation of luminescent materials developed based on the quantum dot size effect. By manipulating the size of the quantum dots, they can emit light at a specific wavelength. Quantum dot display panels offer advantages such as a wide color gamut, low energy consumption, and a tunable spectrum. Quantum dot light-emitting diodes (QLEDs) are optoelectronic devices primarily comprised of an anode, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a cathode. The electron transport layer is typically made of nano-N-type semiconductor materials, which exhibit excellent photocatalytic properties (i.e., they can form photogenerated electrons and holes under laser light). These properties improve with increasing light energy.

[0003] Zinc oxide (ZnO) nanomaterial is one of the common nano-type N-type semiconductor materials. It has a wide bandgap of 3.37 electron volts (eV) and a low work function of 3.7 eV. It also has the advantages of good stability, high transparency, safety and non-toxicity, and is therefore widely used in the preparation of electron transport layers for QLEDs. In QLEDs, ZnO nanomaterials are generally prepared by a solution method as electron transport layers. However, the ZnO nanomaterials prepared by the solution method have a high defect density, resulting in a low carrier mobility on the surface of the electron transport layer, which in turn affects the performance of the QLED. The existing technology has the method of doping metal elements into ZnO nanomaterials to improve carrier mobility, but the doped metal elements are mostly precious metal elements such as aluminum, silver, lithium, gallium, iridium, etc., which are relatively expensive. In addition, if heterogeneous metal elements are doped into ZnO nanomaterials, it is easy to induce lattice mismatch in the ZnO nanomaterials, resulting in a certain degree of distortion in the ZnO nanomaterials.

[0004] Therefore, how to improve the transmission efficiency and stability of the electron transport layer made of ZnO nanomaterials is a technical problem that needs to be urgently solved in the field of QLED display technology. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present application provides a hydrogenated zinc oxide nanomaterial and a preparation method, a thin film and a photoelectric device thereof.

[0006] In a first aspect, the present application provides a hydrogenated zinc oxide nanomaterial, comprising hydrogenated zinc oxide nanoparticles, wherein the hydrogenated zinc oxide nanoparticles are obtained by subjecting zinc oxide nanoparticles to a hydrogenation reduction reaction, wherein the fluorescence intensity of a defect luminescence peak of the hydrogenated zinc oxide nanoparticles within a wavelength range of 500 nanometers to 600 nanometers is at least 17% weaker than the fluorescence intensity of a defect luminescence peak of the zinc oxide nanoparticles at the same position.

[0007] Optionally, the particle size of the hydrogenated zinc oxide nanoparticles is 10 nanometers to 100 nanometers.

[0008] In a second aspect, the present application provides a method for preparing a hydrogenated zinc oxide nanomaterial, comprising the following steps:

[0009] Providing zinc oxide nanoparticles, adding a reducing agent to the zinc oxide nanoparticles to perform a hydrogenation reduction reaction, wherein the molar ratio of the zinc oxide nanoparticles to the reducing agent is 1.0:(0.1-1.0), to obtain a reaction solution containing hydrogenated zinc oxide; and

[0010] performing solid-liquid separation on the reaction solution containing zinc oxide hydride to obtain the zinc oxide hydride nanoparticles;

[0011] The fluorescence intensity of the defect luminescence peak of the hydrogenated zinc oxide nanoparticles within a wavelength range of 500 nm to 600 nm is at least 17% weaker than the fluorescence intensity of the defect luminescence peak of the zinc oxide nanoparticles at the same position.

[0012] Optionally, the reducing agent is at least one of borohydride, ascorbic acid, sulfide and sulfite.

[0013] Optionally, the reaction temperature of the hydrogenation reduction reaction is 50 degrees Celsius to 70 degrees Celsius, and the reaction time is 0.5 hours to 4 hours.

[0014] Optionally, the solid-liquid separation treatment of the reaction liquid containing zinc oxide hydride comprises the steps of: adding an organic solvent to the reaction liquid containing zinc oxide hydride to precipitate and obtain the zinc oxide hydride nanoparticles.

[0015] Optionally, the volume ratio of the reaction solution containing zinc oxide hydride to the organic solvent is 1.0:(1.0-6.0).

[0016] Optionally, the organic solvent is acetone and / or ethyl acetate.

[0017] In a third aspect, the present application provides a thin film, which is prepared using the hydrogenated zinc oxide nanomaterial as described in any one of the first aspects, or the hydrogenated zinc oxide nanomaterial prepared using the preparation method as described in any one of the second aspects.

[0018] In a fourth aspect, the present application provides a photoelectric device, comprising:

[0019] a first electrode;

[0020] a functional layer disposed on the first electrode; and

[0021] a second electrode, disposed on a side of the functional layer away from the first electrode;

[0022] Wherein, the functional layer includes an electron transport layer, and the electron transport layer is prepared using the hydrogenated zinc oxide nanomaterial as described in any one of the first aspects, or is prepared using the hydrogenated zinc oxide nanomaterial obtained by the preparation method as described in any one of the second aspects, or is prepared using the thin film as described in any one of the third aspects.

[0023] Beneficial effects: The present application provides a hydrogenated zinc oxide nanomaterial and a preparation method thereof, a thin film, and a photoelectric device. The hydrogenated zinc oxide nanomaterial includes hydrogenated zinc oxide nanoparticles. The hydrogenated zinc oxide nanoparticles are obtained by partially reducing zinc oxide nanoparticles, that is, hydrogen atoms are introduced into the zinc oxide nanoparticles. The hydrogen atoms can be used as a passivating agent to passivate surface defects of the zinc oxide nanoparticles, thereby inhibiting the formation of oxygen defects, thereby making the fluorescence intensity of the defect luminescence peak of the hydrogenated zinc oxide nanoparticles in the wavelength range of 500 nanometers to 600 nanometers at least 17% weaker than the fluorescence intensity of the defect luminescence peak of the zinc oxide nanoparticles at the same position.

[0024] Hydrogenated zinc oxide nanomaterials can be used to prepare optoelectronic devices, for example, as the electron transport layer of QLED. Compared with the electron transport layer made of zinc oxide nanomaterials, the electron transport layer made of hydrogenated zinc oxide nanomaterials can effectively prevent a large number of carriers from being captured by oxygen defects, thereby increasing the concentration of effective carriers and conductivity, and improving the electron-hole recombination efficiency, so as to enhance the luminescence performance and luminescence stability of optoelectronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0026] Figure 1 Graphs showing the fluorescence spectra of zinc oxide nanoparticles and hydrogenated zinc oxide nanoparticles in the examples of the present application.

[0027] Figure 2 The figure is a schematic flow chart of a method for preparing zinc oxide nanoparticles.

[0028] Figure 3 Schematic diagram of a process for preparing hydrogenated zinc oxide nanoparticles provided in an embodiment of the present application.

[0029] Figure 4 This is a schematic structural diagram of a quantum dot light-emitting device provided in an embodiment of the present application.

[0030] Figure 5 This is a schematic structural diagram of another quantum dot light-emitting device provided in an embodiment of the present application.

[0031] Figure 6 This is a schematic flow chart of a method for preparing a quantum dot light-emitting device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0034] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". The various embodiments of the present application may be 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 understood as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have 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., as well as single numbers within the numbered ranges, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0035] An embodiment of the present application provides a hydrogenated zinc oxide nanomaterial, comprising hydrogenated zinc oxide (H-ZnO) nanoparticles, wherein the H-ZnO nanoparticles are obtained by subjecting zinc oxide (ZnO) nanoparticles to a hydrogenation reduction reaction, wherein the fluorescence intensity of a defect luminescence peak of the H-ZnO nanoparticles within a wavelength range of 500 nanometers to 600 nanometers is at least 17% weaker, for example, 17% to 26% weaker, than the fluorescence intensity of a defect luminescence peak of the ZnO nanoparticles at the same position.

[0036] like Figure 1 As shown, the ZnO nanoparticles before the hydrogenation reduction reaction have a defect luminescence peak 1 in the wavelength range of 500 nm to 600 nm, and the H-ZnO nanoparticles have a defect luminescence peak 2 at the same position. Compared with the fluorescence intensity of the defect luminescence peak 1, the fluorescence intensity of the defect luminescence peak 2 is weakened by 21.7%, thereby effectively inhibiting the formation of oxygen defects.

[0037] In some embodiments of the present application, the particle sizes of the ZnO nanoparticles and the H-ZnO nanoparticles are both 10 nm to 100 nm.

[0038] It should be noted that ZnO nanoparticles, as raw materials for preparing H-ZnO nanoparticles, can be purchased commercially or synthesized by oneself. Figure 2 As shown, the preparation method of ZnO nanoparticles may include the following steps:

[0039] B a , mixing an organic solution containing a zinc salt and an organic solution containing an alkali to react to obtain a reaction solution;

[0040] B b 、For step B a The obtained reaction solution is subjected to solid-liquid separation treatment to obtain ZnO nanoparticles.

[0041] In some embodiments of the present application, in step B a In the process, an organic solution containing zinc salt is used to provide zinc ions (Zn 2+ ), the organic solution containing alkali is used to provide hydroxide ions (OH － ), and OH － With Zn 2+ The molar ratio is (1.5-3.0):1.0. － The molar number is lower than that of Zn 2+ 1.5 times the number of moles of Zn 2+ Cannot be fully converted into ZnO, resulting in Zn 2+ waste; if OH － The molar number is higher than that of Zn 2+If the molar number of ZnO is 3.0 times that of H-ZnO, zinc hydroxide (Zn(OH)2) colloid will be easily generated, thereby affecting the purity of ZnO nanoparticles and further affecting the purity of H-ZnO nanoparticles. It can be understood that OH － With Zn 2+ The molar ratio can be any value in the range of (1.5 to 3.0):1, for example, 1.5:1, 1.8:1, 2.0:1 or 3.0:1.

[0042] In some embodiments of the present application, in step B a In the reaction conditions of the organic solution containing zinc salt and the organic solution containing alkali, the reaction pH is 12 to 14, and the reaction is carried out at room temperature and pressure, wherein the room temperature can be, for example, 25°C, and the room pressure can be, for example, 101325 Pascals (Pa). The zinc salt is a soluble inorganic zinc salt or an organic zinc salt, including but not limited to zinc acetate, zinc nitrate, zinc chloride, and zinc acetate dihydrate. The alkali includes but is not limited to sodium hydroxide, potassium hydroxide, and tetramethylammonium hydroxide. The solvent of the organic solution containing zinc salt is an organic solvent with good solubility for zinc salt, and the solvent of the organic solution containing alkali is an organic solvent with good solubility for alkali. The solvent of the organic solution containing zinc salt and the solvent of the organic solution containing alkali can be the same or different; the solvent of the organic solution containing zinc salt and the solvent of the organic solution containing alkali can be one or more of anhydrous methanol, anhydrous ethanol, and anhydrous butanol, respectively.

[0043] In some embodiments of the present application, the concentration of the zinc salt in the organic solution containing the zinc salt is 0.1 to 1.0 moles per liter (mol / L). It will be appreciated that the concentration of the zinc salt in the organic solution containing the zinc salt can be any value within the range of 0.1 mol / L to 1.0 mol / L, such as 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, or 1.0 mol / L.

[0044] Furthermore, in the organic solution containing alkali, the concentration of the alkali is 0.15 mol / L to 3.0 mol / L, so that OH － With Zn 2+ The molar ratio is (1.5-3.0): 1. It will be appreciated that the concentration of the base can be any value within the range of 0.15 mol / L to 3.0 mol / L, such as 0.15 mol / L, 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L and 3.0 mol / L.

[0045] It should be noted that the concentration of the zinc salt in the organic solution containing the zinc salt and the concentration of the alkali in the organic solution containing the alkali are not specifically limited and can be selected according to actual needs. The only requirement is that the OH － With Zn 2+ The molar ratio is (1.5~3.0):1.

[0046] In some embodiments of the present application, step B b Step B a The obtained reaction solution is subjected to solid-liquid separation treatment, comprising the steps of: a A first organic solvent is added to the obtained reaction solution to precipitate ZnO nanoparticles, that is, the ZnO nanoparticles are precipitated using an organic solvent precipitation method. It should be noted that the solid-liquid separation process may also include other processing steps, such as a filtration separation step.

[0047] Furthermore, step B can be a After the obtained reaction solution is cooled to room temperature, a first organic solvent is added. The first organic solvent may be, for example, anhydrous acetone, ethyl acetate or other organic solvent with low polarity.

[0048] Furthermore, step B a The volume ratio of the obtained reaction liquid to the first organic solvent is 1.0:(1.0-6.0). If the volume of the first organic solvent is lower than the volume of the reaction liquid, it is not conducive to fully precipitating the ZnO nanoparticles, thereby reducing the yield of the ZnO nanoparticles; if the volume of the first organic solvent is higher than six times the volume of the reaction liquid, it will cause waste of the organic solvent, thereby increasing the production cost. It is understandable that step B a The obtained reaction solution was the same as that in step B b The volume ratio of the first organic solvent may be, for example, 1.0:1.0, 1.0:2.0, 1.0:3.0, 1.0:4.0, 1.0:5.0, or 1.0:6.0.

[0049] The present invention also provides a method for preparing a hydrogenated zinc oxide nanomaterial. Figure 3 As shown, the preparation method comprises the following steps:

[0050] B a’ , providing ZnO nanoparticles, adding a reducing agent to the ZnO nanoparticles to perform a hydrogenation reduction reaction, wherein the molar ratio of the ZnO nanoparticles to the reducing agent is 1.0:(0.1-1.0), to obtain a reaction solution containing H-ZnO;

[0051] B b’ 、For step B a’The obtained reaction liquid containing H-ZnO is subjected to solid-liquid separation treatment to obtain H-ZnO nanoparticles.

[0052] For step B a’ It should be noted that the ZnO nanoparticles can be purchased commercially or prepared by oneself. The preparation method of the ZnO nanoparticles can refer to step B. a and B b conduct.

[0053] If the molar number of the reducing agent is less than one tenth of the molar number of the ZnO nanoparticles, the degree of reduction of the ZnO nanoparticles is not ideal, and the formation of oxygen defects cannot be effectively suppressed. The film thus obtained has the disadvantage of limited carrier transport performance. The application of the film in QLED cannot effectively improve the luminous efficiency of the QLED. If the molar number of the reducing agent is higher than the molar number of the ZnO nanoparticles, the ZnO nanoparticles will be over-reduced. Over-reduction will cause the carrier mobility and transmittance of the film to decrease. The application of the film in QLED has the disadvantage of decreased luminous efficiency. It is understood that the molar ratio of ZnO nanoparticles to reducing agent can be, for example, 1.0:0.1, 1.0:0.2, 1.0:0.3, 1.0:0.4, 1.0:0.5, 1.0:0.6, 1.0:0.7, 1.0:0.8, 1.0:0.9 or 1.0:1.0.

[0054] In some embodiments of the present application, for step B a’ The reducing agent can be at least one of borohydride, ascorbic acid, sulfide, and sulfite. The borohydride can be, for example, sodium borohydride or potassium borohydride, the sulfide can be, for example, sodium sulfide, and the sulfite can be, for example, sodium sulfite. The reducing agent can be added to the ZnO nanoparticles in the form of a solvent, such as an organic solution containing sodium borohydride, an organic solution containing ascorbic acid, or an organic solution containing sodium sulfide.

[0055] In some embodiments of the present application, for step B a’ The reaction temperature of the hydrogenation reduction reaction is 50 degrees Celsius (°C) to 70 degrees Celsius (°C), and the reaction time is 0.5 hours (h) to 4 hours (h). For example, in step B c The hydrogenation reduction reaction was carried out under reflux conditions, with a reaction temperature of 60° C. and a reaction time of 2 h.

[0056] In some embodiments of the present application, for step B b’ , the step B a’ The obtained reaction solution containing H-ZnO is subjected to solid-liquid separation treatment, comprising the steps of: a’A second organic solvent is added to the obtained reaction solution containing H-ZnO to precipitate H-ZnO nanoparticles, that is, the H-ZnO nanoparticles are precipitated using an organic solvent precipitation method. It should be noted that the solid-liquid separation process may also include other processing steps, such as a filtration separation step.

[0057] In some embodiments of the present application, the first organic solvent and the second organic solvent are the same, so as to reduce the difficulty of separation and purification of the product (H-ZnO nanoparticles). For example, the first organic solvent and the second organic solvent are both anhydrous acetone.

[0058] In some embodiments of the present application, the volume ratio of the reaction liquid containing H-ZnO to the second organic solvent is 1.0:(1.0~6.0). If the volume of the second organic solvent is lower than the volume of the reaction liquid containing H-ZnO, it is not conducive to the full precipitation of H-ZnO nanoparticles, thereby reducing the yield of H-ZnO nanoparticles; if the volume of the second organic solvent is higher than six times the volume of the reaction liquid containing H-ZnO, it will cause waste of organic solvent, thereby increasing production costs. It is understandable that the volume ratio of the reaction liquid containing H-ZnO formed after the hydrogenation reduction reaction in step Bc to the second organic solvent can be, for example, 1.0:1.0, 1.0:2.0, 1.0:3.0, 1.0:4.0, 1.0:5.0 or 1.0:6.0.

[0059] It should be noted that the solution method is preferably used to prepare H-ZnO nanomaterials in the embodiment of the present application. Compared with the solid-phase method for preparing H-ZnO nanomaterials, the advantages of the solution method for preparing H-ZnO nanomaterials are: first, the entire reaction process is more moderate and not prone to over-reduction, which is conducive to controlling the degree of reduction of ZnO nanoparticles and avoiding the adverse effects of over-reduction; second, due to process limitations, the solid-phase method usually obtains H-ZnO nanomaterials with nanoarray morphology, which are large in size (for example, a diameter of 50 nm and a length greater than 1 μm), and there are a large number of intercalated particles in the nanoarray. The H-ZnO nanomaterials prepared by the solution method include H-ZnO nanoparticles with a size of 5nm to 10nm. The H-ZnO nanoparticles can be effectively dispersed in the solvent and easily form a dense film during film formation. Third, the hydrogenation reduction reaction in the solid-phase method is usually carried out under high-temperature (e.g., 350°C) calcination conditions, and the product is prone to agglomeration and has poor dispersion. The H-ZnO nanoparticles prepared by the solution method have ideal dispersion, which is conducive to film formation, and can be formed into films by various methods such as spin coating, printing, doctor blade coating, immersion, and spraying.

[0060] An embodiment of the present application further provides a thin film, which is prepared using the aforementioned H-ZnO nanomaterial, or is prepared using the H-ZnO nanomaterial prepared using the aforementioned preparation method, and the thin film can be used to prepare optoelectronic devices.

[0061] In some embodiments of the present application, the film is used to prepare the electron transport layer of QLED. Since H-ZnO nanomaterials can effectively inhibit the formation of oxygen defects, the electron transport layer made of H-ZnO nanomaterials can effectively prevent a large number of carriers from being captured by oxygen defects, thereby increasing the concentration and conductivity of effective carriers, and improving the electron-hole recombination efficiency, so as to enhance the luminescence performance and luminescence stability of the optoelectronic device.

[0062] In some embodiments of the present application, the thin film can be prepared by a solution method, a deposition method, etc., wherein the solution method includes but is not limited to spin coating, coating, printing, doctor blading, dip pulling, soaking, spraying, roller coating and casting, and the deposition method includes but is not limited to electrochemical deposition, evaporation deposition and sputtering deposition.

[0063] As an example, the thin film is prepared by a spin coating process, specifically: first, H-ZnO nanoparticles are dispersed in an organic solvent to prepare an H-ZnO nanoparticle dispersion liquid, and the organic solvent can be a single organic solvent or a combination of multiple organic solvents. For example, the organic solvent in the H-ZnO nanoparticle dispersion liquid is anhydrous methanol, anhydrous ethanol or anhydrous butanol; then, the H-ZnO nanoparticle dispersion liquid is spin-coated on a substrate, and the spin coating process parameters can be selected according to actual needs and are not specifically limited here; finally, a drying process is performed to obtain the thin film.

[0064] The concentration of the H-ZnO nanoparticles in the H-ZnO nanoparticle dispersion is 20 mg / mL to 50 mg / mL. If the concentration of the H-ZnO nanoparticles is lower than 20 mg / mL or higher than 50 mg / mL, the film obtained from the H-ZnO nanoparticles may be used in a photoelectric device and may negatively affect the luminous efficiency of the photoelectric device. It is understood that the concentration of the H-ZnO nanoparticles in the H-ZnO nanoparticle dispersion can be any value within the range of 20 mg / mL to 50 mg / mL, such as 20 mg / mL, 30 mg / mL, 40 mg / mL, or 50 mg / mL.

[0065] The present application also provides an optoelectronic device, which may be, for example, an organic electroluminescent device, a quantum dot light-emitting device, or the like. The optoelectronic device includes: a first electrode, a functional layer, and a second electrode, wherein the functional layer is disposed on the first electrode, and the second electrode is disposed on a side of the functional layer away from the first electrode, that is, the functional layer is located between the first electrode and the second electrode, wherein the functional layer includes an electron transport layer, and the electron transport layer is prepared using the aforementioned H-ZnO nanomaterial, or is prepared using the H-ZnO nanomaterial prepared using the aforementioned preparation method, or is prepared using the aforementioned thin film.

[0066] The following description will be made using a quantum dot light-emitting device as an example.

[0067] A quantum dot light emitting device, such as Figure 4 As shown, the quantum dot light-emitting device 1 includes a substrate 11, and a first electrode 12, a functional layer 13 and a second electrode 14 arranged on the substrate 11, and the functional layer 13 is arranged between the first electrode 12 and the second electrode 14; the functional layer 13 includes a hole transport layer 131, a quantum dot layer 132 and an electron transport layer 133, wherein the quantum dot layer 132 is arranged between the hole transport layer 131 and the electron transport layer 133, and the material of the electron transport layer 133 is the electron transport layer film provided in the embodiment of the present application.

[0068] Specifically, the quantum dot light emitting device can be a positive structure or an inverted structure. When the quantum dot light emitting device is a positive structure, continue to refer to Figure 4 , the first electrode 12 is an anode, the second electrode 14 is a cathode, the hole transport layer 131 is arranged on the side of the first electrode 12 away from the substrate 11, and the electron transport layer 133 is arranged between the second electrode 14 and the quantum dot layer 132. When the quantum dot light emitting device is an inversion structure, such as Figure 5 As shown, the first electrode 12 is a cathode, the second electrode layer 14 is an anode, the electron transport layer 133 is arranged on the side of the first electrode 12 away from the substrate 11, and the hole transport layer 131 is arranged between the second electrode 14 and the quantum dot layer 132.

[0069] It is understandable that a hole injection layer and an electron blocking layer may be provided between the anode and the hole transport layer, and a hole blocking layer and an electron injection layer may be provided between the cathode and the electron transport layer.

[0070] In the embodiments of the present application, the materials of the other layer structures in the quantum dot light-emitting device except the electron transport layer can be materials commonly used in the art, such as:

[0071] The substrate may be a rigid substrate or a flexible substrate. An example substrate material is glass.

[0072] The material of the anode may be a transparent metal oxide, and an example of the material of the anode is indium tin oxide (In2O3:Sn, ITO).

[0073] The material of the cathode can be a pure metal, an alloy or a transparent metal oxide. An example of the material of the cathode is aluminum.

[0074] The material of the hole transport layer can be one or more of TFB (poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine)), P3HT (3-hexyl substituted polythiophene), PVK (poly(9-vinylcarbazole)), poly-TPD (poly[bis(4-phenyl)(4-butylphenyl)amine]), TCTA (4,4',4'-tris(carbazole-9-yl)triphenylamine), CBP (4,4'-bis(9-carbazole)biphenyl), PEDOT (3,4-ethylenedioxythiophene monomer) and PSS (polystyrene sulfonate).

[0075] The material of the quantum dot layer can be one or more of group II-VI single-component quantum dots or core-shell structure quantum dots or alloy structure quantum dot materials, group III-V single-component quantum dots or core-shell structure quantum dots or alloy structure quantum dot materials, organic-inorganic hybrid perovskite quantum dot materials and all-inorganic perovskite quantum dot materials.

[0076] The present invention also provides a method for preparing a quantum dot light-emitting device. Figure 6 As shown, the preparation method comprises the steps of:

[0077] B1. providing a substrate, and forming a first electrode on the substrate;

[0078] B2. Forming a functional layer on the first electrode, the functional layer comprising a hole transport layer, a quantum dot layer, and an electron transport layer, wherein the quantum dot layer is disposed between the hole transport layer and the electron transport layer, and the electron transport layer is made of H-ZnO nanomaterial or a thin film made of H-ZnO nanomaterial;

[0079] B3. Forming a second electrode on a side of the functional layer away from the first electrode.

[0080] It should be noted that the methods for preparing the first electrode, the functional layer and the second electrode include but are not limited to solution methods and deposition methods, wherein the solution method includes but is not limited to spin coating, coating, printing, doctor blading, dip pulling, immersion, spraying, roller coating and casting, and the deposition method includes but is not limited to electrochemical deposition, evaporation deposition and sputtering deposition.

[0081] The following is a detailed description of the preparation method using a positive-type quantum dot light-emitting device as an example. Figure 5 As shown, the preparation method comprises the following steps:

[0082] B10. providing a substrate, and forming an anode on the substrate;

[0083] B20, forming a hole transport layer on the side of the anode away from the substrate in step B10;

[0084] B30, forming a quantum dot layer on the side of the hole transport layer away from the anode in step B20;

[0085] B40, forming an electron transport layer on a side of the quantum dot layer away from the hole transport layer in step B30, wherein the electron transport layer is made of H-ZnO nanomaterial or a thin film made of H-ZnO nanomaterial;

[0086] B50. Form a cathode on the side of the electron transport layer away from the quantum dot layer in step B40.

[0087] In step B10, the anode is prepared by forming an anode material on a substrate using a solution method and then drying the anode to obtain the anode. The solution method includes but is not limited to spin coating, coating, printing, doctor blading, dip coating, immersion, spray coating, roller coating, and casting.

[0088] In order to improve the quality of the electron transport layer obtained in step B40, the substrate containing the anode needs to be pretreated. An example of the pretreatment steps is: first, the substrate containing the anode is cleaned with a detergent to preliminarily remove surface stains; then, deionized water is used for ultrasonic cleaning for 20 minutes (min); then, acetone is used for ultrasonic cleaning for 20 minutes; then, anhydrous ethanol is used for ultrasonic cleaning for 20 minutes; then, deionized water is used for ultrasonic cleaning for 20 minutes; finally, high-purity nitrogen is used for drying.

[0089] In step B20, the method for preparing the hole transport layer may be: forming a hole transport layer material on the anode using a solution method, and then performing a thermal annealing treatment to obtain the hole transport layer, wherein the solution method includes but is not limited to spin coating, coating, printing, doctor blading, dip pulling, soaking, spraying, roller coating, and casting. The concentration of the hole transport layer material, the process parameters of the solution method, and the temperature of the thermal annealing treatment can be selected according to actual needs. The thickness of the hole transport layer is controlled by adjusting the concentration of the hole transport layer material and the process parameters of the solution method. If the hole transport layer is too thick or too thin, it will lead to an electron-hole imbalance inside the quantum dot light-emitting device, thereby negatively affecting the performance of the quantum dot light-emitting device. The thickness of the hole transport layer can be, for example, 20 nanometers to 40 nanometers.

[0090] In step B30, the quantum dot layer can be prepared by forming a quantum dot layer material on the hole transport layer using a solution method, followed by drying to obtain the quantum dot layer. Solution methods include, but are not limited to, spin coating, coating, printing, doctor blade coating, dip-pull-up, soaking, spraying, roller coating, and casting. The concentration of the quantum dot layer material, the process parameters of the solution method, and the drying temperature can be selected according to actual needs. The thickness of the quantum dot layer can be controlled by adjusting the concentration of the quantum dot layer material and the process parameters of the solution method. The thickness of the quantum dot layer can be, for example, 25 to 50 nanometers.

[0091] In step B40, the method for preparing the electron transport layer may be: first, the prepared H-ZnO nanoparticles are dispersed in an organic solvent to obtain an H-ZnO nanoparticle dispersion, the organic solvent being, for example, anhydrous ethanol; then, the H-ZnO nanoparticle dispersion is formed on the quantum dot layer using a solution method, and then thermally annealed to obtain the electron transport layer. The thickness of the electron transport layer is controlled by adjusting the concentration of the electron transport layer material and the process parameters of the solution method. An electron transport layer that is too thick or too thin will lead to an electron-hole imbalance within the quantum dot light-emitting device, thereby negatively affecting the performance of the quantum dot light-emitting device. The thickness of the electron transport layer may be, for example, 20 to 60 nanometers.

[0092] In step B50, the method for preparing the cathode may be: evaporating a metal material on the electron transport layer through a vacuum evaporation process to form the cathode. The thickness of the cathode may be, for example, 60 nanometers to 100 nanometers.

[0093] It is understood that the method for preparing the quantum dot light-emitting device may further include the steps of sequentially preparing a hole injection layer and an electron blocking layer between the anode and the hole transport layer. The method for preparing the quantum dot light-emitting device may further include the steps of sequentially preparing a hole blocking layer and an electron injection layer between the cathode and the electron transport layer, wherein the methods for preparing the hole injection layer, the electron blocking layer, the hole blocking layer, and the electron injection layer include, but are not limited to, solution methods and deposition methods. The method for preparing the quantum dot light-emitting device may further include a packaging process step, which may be machine packaging or manual packaging. Preferably, the concentration of oxygen and water in the environment in which the packaging process is performed is less than 0.1 ppm.

[0094] Example 1

[0095] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles is as follows:

[0096] 1.1 Reagents:

[0097] (1) 0.5 mol / L zinc chloride-methanol solution: dissolve 20.45 g of zinc chloride in an appropriate amount of anhydrous methanol, and then continue to add anhydrous methanol to make up to 30 mL;

[0098] (2) 0.5 mol / L sodium hydroxide-methanol solution: dissolve 0.6 g of sodium hydroxide in an appropriate amount of anhydrous methanol, and then continue to add anhydrous methanol to make up to 30 mL;

[0099] (3) 1 mol / L sodium borohydride-methanol solution: dissolve 5.67 g of sodium borohydride in an appropriate amount of anhydrous methanol, and then continue to add anhydrous methanol to make up to 30 mL;

[0100] (4) Anhydrous acetone, commercially available;

[0101] (5) Anhydrous ethanol, commercially available.

[0102] 1.2 Preparation steps

[0103] B1.2.1. Add 10 mL of 0.5 mol / L sodium hydroxide-methanol solution to 30 mL of a 0.5 mol / L zinc chloride-methanol solution. Stir thoroughly at 25°C and atmospheric pressure to obtain a clear, transparent reaction solution.

[0104] B1.2.2. Add 20 mL of anhydrous acetone to the reaction solution of step B1.2.1 to precipitate ZnO nanoparticles;

[0105] B1.2.3. Add 10 mL of 1 mol / L sodium borohydride-methanol solution to the ZnO nanoparticles prepared in step B1.2.2, and reflux the mixture at 60°C for 2 h to obtain a reaction solution.

[0106] B1.2.4. Add 20 mL of anhydrous acetone to the reaction solution of step B1.2.3 to prepare H-ZnO nanoparticles.

[0107] The H-ZnO nanoparticles prepared in step B1.2.4 were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0108] Example 2

[0109] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles is as follows:

[0110] 2.1 Reagents:

[0111] (1) 0.5 mol / L zinc nitrate-ethanol solution: dissolve 44.62 g of zinc nitrate in an appropriate amount of anhydrous ethanol, and then continue to add anhydrous ethanol to make up to 30 mL;

[0112] (2) 0.5 mol / L potassium hydroxide-ethanol solution: dissolve 8.42 g of potassium hydroxide in an appropriate amount of anhydrous ethanol, and then continue to add anhydrous ethanol to make up to 30 mL;

[0113] (3) 0.5 mol / L ascorbic acid-ethanol solution, prepared as follows: 13.21 g of ascorbic acid was dissolved in an appropriate amount of anhydrous ethanol, and then anhydrous ethanol was added to make the volume 30 mL. The CAS number of ascorbic acid is 62624-30-0.

[0114] (4) Anhydrous acetone, commercially available;

[0115] (5) Anhydrous ethanol, commercially available.

[0116] 2.2 Preparation steps

[0117] B2.2.1. Add 10 mL of 0.5 mol / L potassium hydroxide-ethanol solution to 30 mL of a 0.5 mol / L zinc nitrate-ethanol solution. Stir thoroughly at 25°C and atmospheric pressure to obtain a clear, transparent reaction solution.

[0118] B2.2.2. Add 20 mL of anhydrous acetone to the reaction solution of step B2.2.1 to precipitate ZnO nanoparticles;

[0119] B2.2.3. Add 10 mL of 1 mol / L ascorbic acid-ethanol solution to the ZnO nanoparticles prepared in step B2.2.2, and reflux the mixture at 60°C for 2 h to obtain a reaction solution.

[0120] B2.2.4. Add 20 mL of anhydrous acetone to the reaction solution of step B2.2.3 to prepare H-ZnO nanoparticles.

[0121] The H-ZnO nanoparticles prepared in step B2.2.4 were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0122] Example 3

[0123] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles is as follows:

[0124] 3.1 Reagents:

[0125] (1) 0.5 mol / L zinc acetate-methanol solution: dissolve 27.52 g of zinc acetate in an appropriate amount of anhydrous methanol, and then continue to add anhydrous methanol to make up to 30 mL;

[0126] (2) 0.5 mol / L tetramethylammonium hydroxide-methanol solution, prepared as follows: 13.67 g of tetramethylammonium hydroxide was dissolved in an appropriate amount of anhydrous methanol, and then anhydrous methanol was added to make the volume 30 mL;

[0127] (3) 1 mol / L sodium sulfide-methanol solution: dissolve 11.71 g of sodium sulfide in an appropriate amount of anhydrous methanol, and then continue to add anhydrous methanol to make up to 30 mL;

[0128] (4) Anhydrous acetone, commercially available;

[0129] (5) Anhydrous ethanol, commercially available.

[0130] 3.2 Preparation steps

[0131] B3.2.1. Add 10 mL of 0.5 mol / L tetramethylammonium hydroxide-methanol solution to 30 mL of a 0.5 mol / L zinc acetate-methanol solution. Stir thoroughly at 25°C and atmospheric pressure to obtain a clear, transparent reaction solution.

[0132] B3.2.2. Add 20 mL of anhydrous acetone to the reaction solution from step B3.2.1 to precipitate ZnO nanoparticles;

[0133] B3.2.3. Add 10 mL of 1 mol / L sodium sulfide-methanol solution to the ZnO nanoparticles prepared in step B3.2.2, and reflux the mixture at 60°C for 2 h to obtain a reaction solution.

[0134] B3.2.4. Add 20 mL of anhydrous acetone to the reaction solution of step B3.2.3 to prepare H-ZnO nanoparticles.

[0135] The H-ZnO nanoparticles prepared in step B3.2.4 were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0136] Example 4

[0137] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the sodium borohydride-methanol solution is 2 mol / L.

[0138] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0139] Example 5

[0140] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the sodium borohydride-methanol solution is 3 mol / L.

[0141] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0142] Example 6

[0143] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the ascorbic acid-ethanol solution is 0.5 mol / L.

[0144] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0145] Example 7

[0146] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the ascorbic acid-ethanol solution is 3.0 mol / L.

[0147] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0148] Example 8

[0149] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the sodium sulfide-methanol solution is 0.5 mol / L.

[0150] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0151] Example 9

[0152] This embodiment provides an H-ZnO nanomaterial, which includes H-ZnO nanoparticles. The preparation method of the H-ZnO nanoparticles in this embodiment is different from that in Example 1 only in that the concentration of the sodium sulfide-methanol solution is 3.0 mol / L.

[0153] The prepared H-ZnO nanoparticles were fully dispersed in anhydrous ethanol to obtain a H-ZnO nanoparticle dispersion for later use, wherein the concentration of the H-ZnO nanoparticles was 30 mg / mL.

[0154] Example 10

[0155] This embodiment provides a quantum dot light emitting device. The structure of the quantum dot light emitting device is as follows: Figure 3 As shown, it includes a substrate, an anode, a hole transport layer, a quantum dot layer, an electron transport layer, and a cathode arranged in sequence. The substrate is made of glass. The anode is made of ITO, and the thickness of the anode is 60 nanometers. The hole transport layer is made of TFB, and the thickness of the hole transport layer is 40 nanometers. The quantum dot layer is made of blue quantum dots Cd x Zn y Se 1-x-y , and the quantum dot layer has a thickness of 30 nanometers. The electron transport layer is made of a thin film made from the H-ZnO nanoparticle dispersion in Example 1, and has a thickness of 30 nanometers. The cathode is made of aluminum, and has a thickness of 40 nanometers.

[0156] Example 11

[0157] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 2.

[0158] Example 12

[0159] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 3.

[0160] Example 13

[0161] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 4.

[0162] Example 14

[0163] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 5.

[0164] Example 15

[0165] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 6.

[0166] Example 16

[0167] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 7.

[0168] Example 17

[0169] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 8.

[0170] Example 18

[0171] This embodiment provides a quantum dot light-emitting device, which differs from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is a thin film made from the H-ZnO nanoparticle dispersion in Example 9.

[0172] Comparative Example 1

[0173] This comparative example provides a quantum dot light-emitting device, which is different from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is different.

[0174] The material of the electron transport layer in this comparative example is a thin film made of ZnO nanoparticle dispersion, wherein the ZnO nanoparticle dispersion is prepared by fully dispersing ZnO nanoparticles in anhydrous ethanol, wherein the concentration of the ZnO nanoparticles is 30 mg / mL, and the ZnO nanoparticles are purchased from Sigma.

[0175] Comparative Example 2

[0176] This comparative example provides a quantum dot light-emitting device, which is different from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is different.

[0177] In this comparative example, the material of the electron transport layer is a thin film made from a H-ZnO nanoparticle dispersion, wherein the H-ZnO nanoparticle dispersion is prepared by fully dispersing H-ZnO nanoparticles in anhydrous ethanol, and the concentration of the H-ZnO nanoparticles is 30 mg / mL. The only difference between the preparation method of the H-ZnO nanoparticles and that of Example 1 is that the 1 mol / L sodium borohydride-methanol solution in Example 1 is replaced with a 5 mol / L sodium borohydride-methanol solution.

[0178] Comparative Example 3

[0179] This comparative example provides a quantum dot light-emitting device, which is different from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is different.

[0180] In this comparative example, the material of the electron transport layer is a thin film made from a H-ZnO nanoparticle dispersion, wherein the H-ZnO nanoparticle dispersion is prepared by fully dispersing H-ZnO nanoparticles in anhydrous ethanol, and the concentration of the H-ZnO nanoparticles in the H-ZnO nanoparticle dispersion is 30 mg / mL. The only difference between the preparation method of the H-ZnO nanoparticles and that of Example 2 is that the 0.5 mol / L ascorbic acid-ethanol solution in Example 2 is replaced with a 5 mol / L ascorbic acid-ethanol solution.

[0181] Comparative Example 4

[0182] This comparative example provides a quantum dot light-emitting device, which is different from the quantum dot light-emitting device of Example 9 only in that the material of the electron transport layer is different.

[0183] The material of the electron transport layer in this comparative example is a thin film made from a H-ZnO nanoparticle dispersion, wherein the H-ZnO nanoparticle dispersion is prepared by fully dispersing H-ZnO nanoparticles in anhydrous ethanol, and the concentration of the H-ZnO nanoparticles in the H-ZnO nanoparticle dispersion is 30 mg / mL, and the only difference between the preparation method of the H-ZnO nanoparticles and that of Example 3 is that the 1 mol / L sodium sulfide-methanol solution in Example 3 is replaced by a 5 mol / L sodium sulfide-methanol solution.

[0184] Test example

[0185] The quantum dot light-emitting devices of Examples 10 to 18 and Comparative Examples 1 to 4 were subjected to performance tests to obtain the external quantum efficiency and turn-on voltage of each quantum dot light-emitting device. The external quantum efficiency data and turn-on voltage data of each quantum dot light-emitting device were obtained using an external quantum efficiency optical testing instrument.

[0186] The performance test structure is detailed in Table 1 below:

[0187] Table 1 Performance test results of various quantum dot light-emitting devices in the experimental examples

[0188] Quantum dot device number External quantum efficiency (%) Turn-on voltage (V) Example 10 6.85 2.65 Example 11 6.11 3.15 Example 12 5.47 3.33 Example 13 7.11 2.44 Example 14 5.80 3.10 Example 15 6.46 3.11 Example 16 5.55 3.21 Example 17 5.18 3.47 Example 18 4.97 3.21 Comparative Example 1 2.59 5.77 Comparative Example 2 2.14 4.17 Comparative Example 3 2.55 5.68 Comparative Example 4 3.01 5.74

[0189] It can be seen from Table 1 that compared with the quantum dot light-emitting devices of Comparative Examples 1 to 4, the external quantum efficiency of the quantum dot light-emitting devices of Examples 10 to 18 is significantly improved, and the turn-on voltage is significantly reduced, indicating that the quantum dot light-emitting devices of Examples 10 to 18 have ideal luminescence performance and luminescence stability.

[0190] From Examples 10, 13, 14, and Comparative Example 2, it can be seen that when the concentration of the reducing agent sodium borohydride-methanol solution is 0.5 mol / L to 3 mol / L, the H-ZnO nanoparticles obtained are used to prepare the electron transport layer of the quantum dot light-emitting device. The obtained quantum dot light-emitting device has ideal luminescence performance, and the preferred concentration of the sodium borohydride-methanol solution is 2 mol / L. When the concentration of the sodium borohydride-methanol solution is greater than 3 mol / L, for example, 5 mol / L (corresponding to Comparative Example 2), it will cause excessive reduction of the ZnO nanoparticles, which is not conducive to improving the luminous efficiency and stability of the quantum dot light-emitting device.

[0191] It can be seen from Example 11, Example 15, Example 16 and Comparative Example 3 that when the concentration of the reducing agent ascorbic acid-ethanol solution is 0.5 mol / L to 3 mol / L, the obtained H-ZnO nanoparticles are used to prepare the electron transport layer of the quantum dot light-emitting device. The obtained quantum dot light-emitting device has ideal luminous performance, and the preferred ascorbic acid-ethanol solution concentration is 0.5 mol / L. When the concentration of the ascorbic acid-ethanol solution is greater than 3 mol / L, for example, 5 mol / L (corresponding to Comparative Example 3), it will cause excessive reduction of the ZnO nanoparticles, which is not conducive to improving the luminous efficiency and stability of the quantum dot light-emitting device.

[0192] It can be seen from Examples 12, 17, 18, and Comparative Example 4 that when the concentration of the reducing agent sodium sulfide-methanol solution is 0.5 mol / L to 3 mol / L, the H-ZnO nanoparticles obtained are used to prepare the electron transport layer of the quantum dot light-emitting device. The obtained quantum dot light-emitting device has ideal luminescence performance, and the preferred resistance to the sodium sulfide-methanol solution concentration is 1.0 mol / L. When the concentration of the sodium sulfide-methanol solution is greater than 3 mol / L, for example, 5 mol / L (corresponding to Comparative Example 3), it will cause excessive reduction of the ZnO nanoparticles, which is not conducive to improving the luminous efficiency and stability of the quantum dot light-emitting device.

[0193] The above is a detailed introduction to a hydrogenated zinc oxide nanomaterial and its preparation method, thin film and optoelectronic device provided in the embodiments of this application. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a hydrogenated zinc oxide nanomaterial, characterized in that: The steps include: Providing zinc oxide nanoparticles, adding an organic solution containing a reducing agent to the zinc oxide nanoparticles to perform a hydrogenation reduction reaction, wherein the molar ratio of the zinc oxide nanoparticles to the reducing agent is 1.0:(0.1-1.0), to obtain a reaction solution containing hydrogenated zinc oxide; and performing solid-liquid separation on the reaction solution containing zinc oxide hydride to obtain the zinc oxide hydride nanoparticles; The fluorescence intensity of the defect luminescence peak of the hydrogenated zinc oxide nanoparticles in the wavelength range of 500 nm to 600 nm is at least 17% weaker than the fluorescence intensity of the defect luminescence peak of the zinc oxide nanoparticles at the same position; the reaction temperature of the hydrogenation reduction reaction is 50°C to 70°C, and the reaction time is 0.5 hour to 4 hours; The reducing agent is at least one of borohydride, ascorbic acid, sulfide salt and sulfite.

2. The preparation method according to claim 1, characterized in that The solid-liquid separation treatment of the reaction liquid containing zinc oxide hydride comprises the steps of: adding an organic solvent to the reaction liquid containing zinc oxide hydride to precipitate and obtain the zinc oxide hydride nanoparticles.

3. The preparation method according to claim 2, characterized in that The volume ratio of the reaction solution containing zinc oxide hydride to the organic solvent is 1.0:(1.0-6.0).

4. The preparation method according to claim 2, characterized in that The organic solvent is acetone and / or ethyl acetate.

5. The preparation method according to claim 1, characterized in that The particle size of the hydrogenated zinc oxide nanoparticles is 5 nanometers to 10 nanometers.

6. A film, characterized in that The raw material of the film is prepared by using hydrogenated zinc oxide nanomaterial prepared by the preparation method described in any one of claims 1 to 5.

7. A photoelectric device, characterized in that: The optoelectronic device comprises: a first electrode; a functional layer disposed on the first electrode; and a second electrode, disposed on a side of the functional layer away from the first electrode; Wherein, the functional layer includes an electron transport layer, and the electron transport layer is prepared by using the hydrogenated zinc oxide nanomaterial prepared by the preparation method according to any one of claims 1 to 5, or is prepared by using the thin film according to claim 6.

8. The optoelectronic device according to claim 7, wherein: The optoelectronic device is a quantum dot light-emitting device, and the functional layer further comprises a hole transport layer and a quantum dot layer, wherein the quantum dot layer is arranged between the hole transport layer and the electron transport layer; The quantum dot light-emitting device also includes a substrate. When the quantum dot light-emitting device is a positive structure, the first electrode is an anode and the second electrode is a cathode, the hole transport layer is arranged on the side of the first electrode away from the substrate, and the electron transport layer is arranged between the second electrode and the quantum dot layer; or, when the quantum dot light-emitting device is an inverted structure, the first electrode is a cathode and the second electrode is an anode, the electron transport layer is arranged on the side of the first electrode away from the substrate, and the hole transport layer is arranged between the second electrode and the quantum dot layer.

9. The optoelectronic device according to claim 8, characterized in that The material of the hole transport layer is selected from one or more of poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), 3-hexyl-substituted polythiophene, poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl)amine], 4,4',4'-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazol)biphenyl, 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate; The material of the quantum dot layer is selected from one or more of group II-VI single-component quantum dots or core-shell structure quantum dots or alloy structure quantum dot materials, group III-V single-component quantum dots or core-shell structure quantum dots or alloy structure quantum dot materials, organic-inorganic hybrid perovskite quantum dot materials and all-inorganic perovskite quantum dot materials.

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