WO2023142565A1 - Nanocomplex, method for preparing same, and light-emitting device - Google Patents

Abstract

Disclosed are a nanocomplex, a method for preparing the same, and a light-emitting device. The nanocomplex comprises a metal oxide nanocore and an electrically conductive polymer shell layer coating the metal oxide nanocore.

Description

Nanocomposite material and its preparation method, light-emitting device

This application claims the priority of the Chinese patent application with the application number 202210101471.6 and the application title "Nanocomposite material and its preparation method, light-emitting device" filed at the China Patent Office on January 27, 2022, the entire content of which is incorporated by reference incorporated in this application.

technical field

The application relates to the field of materials, in particular to a nanocomposite material, a preparation method thereof, and a light emitting device.

Background technique

Quantum Dot (QD) is a semiconductor cluster with a size of 1nm to 10nm. Due to the quantum size effect, people can achieve the required specific wavelength of light by adjusting the size of the quantum dot. It can be applied to light-emitting diodes, solar energy Batteries, bioluminescence labeling and other fields.

In a traditional quantum dot light-emitting doit (QLED), electrons and holes are injected from the cathode and anode, respectively, and then recombine in the quantum dot light-emitting layer to form excitons to emit light. QLED has a series of advantages such as high color saturation, adjustable luminous color, and low energy consumption, and has become a strong competitor for the next generation of display devices.

However, there are still many problems in the research and development process of light-emitting devices represented by QLEDs, such as leakage current problems in light-emitting devices, and luminous efficiency needs to be improved.

technical solution

Therefore, the present application provides a nanocomposite material, a preparation method thereof, and a light emitting device.

The embodiment of the present application provides a nanocomposite material, including:

A metal oxide nano core, and a conductive polymer shell covering the metal oxide nano core.

Optionally, in some embodiments of the present application, the particle size of the nanocomposite material is 10 nm˜15 nm.

Optionally, in some embodiments of the present application, the thickness of the conductive polymer shell layer is 3 nm˜5 nm.

Optionally, in some embodiments of the present application, the particle size of the metal oxide nano-core is 7nm-10nm.

Optionally, in some embodiments of the present application, the conductive polymer is poly(1,5-diaminoanthraquinone), polyaniline, poly(1-aminoanthraquinone) or poly(2-aminoanthraquinone) one or more of .

Optionally, in some embodiments of the present application, the metal oxide is selected from: ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, ZnSnO, ZnLiO or InSnO one or more of.

Optionally, in some embodiments of the present application, the nanocomposite material is composed of a metal oxide nanocore and a conductive polymer shell covering the metal oxide nanocore.

Correspondingly, the embodiment of the present application also provides a method for preparing a nanocomposite material, the method comprising:

providing a sol comprising metal oxide nanoparticles; and

adding a conductive polymer monomer and an oxidizing agent to the sol containing oxide nanoparticles, and performing a polymerization reaction to obtain the nanocomposite material;

Wherein, the nano-composite material includes a metal oxide nano-core and a conductive polymer shell covering the metal oxide nano-core.

Optionally, in some embodiments of the present application, the molar ratio of the conductive polymer monomer to the metal oxide nanoparticles is (1-5):20; and/or

The molar ratio of the oxidizing agent to the conductive polymer monomer is (1-2):2; and/or

The oxidant is selected from one or more of ammonium persulfate or hydrogen peroxide; and/or

The conductive polymer monomer is one or more of 1,5-diaminoanthraquinone, aniline, 1-aminoanthraquinone or 2-aminoanthraquinone; and/or

The metal oxide nanoparticle sol includes the metal oxide nanoparticles, a surfactant and water, and the surfactant is selected from one of sodium dodecylsulfonate, sodium laurate or polyethylene glycol or more.

Optionally, in some embodiments of the present application, adding a conductive polymer monomer and an oxidizing agent to the sol containing metal oxide nanoparticles to perform a polymerization reaction to obtain the nanocomposite material includes:

Add conductive polymer monomers to the sol containing oxide nanoparticles, and ultrasonically disperse to obtain an intermediate mixed solution;

The oxidizing agent is added into the intermediate mixed solution and mixed to carry out a polymerization reaction to obtain the nanocomposite material.

Optionally, in some embodiments of the present application, the conductive polymer monomer is 1,5-diaminoanthraquinone, the mixing treatment time is 5h-10h, and the temperature is 3°C-10°C; and /or

The time for the ultrasonic dispersion treatment is 5 minutes to 30 minutes.

Optionally, in some embodiments of the present application, the step of providing a sol containing metal oxide nanoparticles includes:

Mix the deionized water or ethylene glycol solution of the precipitating agent with the salt evenly, then hydrothermally react at 120°C-180°C for 5h-10h, filter the product after cooling to room temperature, and wash with water and ethanol for several times, and then Obtaining metal oxide nanoparticles through drying;

The metal oxide nanoparticles are added into the aqueous solution of the surfactant, and ultrasonically dispersed for 5 minutes to 30 minutes to form a stably dispersed metal oxide nanoparticle sol.

Optionally, in some embodiments of the present application, the molar ratio of the precipitation agent to the salt is (1-2):6.

Optionally, in some embodiments of the present application, the salt includes a zinc salt, and the zinc salt includes one or more of zinc acetate, zinc citrate, and zinc lactate;

The precipitant is one or more of urea, hexamethylenetetramine, tetramethylammonium hydroxide or sodium hydroxide;

The surfactant is selected from one or more of sodium dodecylsulfonate, sodium laurate or polyethylene glycol.

Correspondingly, the embodiment of the present application also provides a light emitting device, which includes:

Cathode, electron transport layer, light-emitting layer and anode stacked in sequence;

Wherein, the material of the electron transport layer includes the above-mentioned nanocomposite material, or includes the nanocomposite material made by the above-mentioned method.

Optionally, in some embodiments of the present application, the material of the anode is selected from one or more of indium-doped tin oxide, fluorine-doped tin oxide, tin-doped zinc oxide or indium-doped zinc oxide ;and / or

The material of the light-emitting layer includes quantum dots, the quantum dots are selected from one or more of II-VI group compounds, III-V group compounds and I-III-VI group compounds, and the II-VI group compounds One or more selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS; CdZnSeS, CdZnSeTe or CdZnSTe; the III -V group compound is selected from one or more of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP or InAlNP; the I-III-VI group compound is selected from CuInS ₂ , CuInSe ₂ or AgInS ₂ or one or more; and/or

The material of the cathode is selected from one or more of Al, Cu, Mo, Au, Ag or MoO ₃ .

Optionally, in some embodiments of the present application, the light emitting device further includes a hole transport layer and a hole injection layer, the hole injection layer is arranged between the anode and the light emitting layer, the a hole transport layer is disposed between the hole injection layer and the light emitting layer;

The material of the hole injection layer is selected from one or more of PEDOT:PSS, NiO, MoO ₃ , WO ₃ or V ₂ O ₅ ;

The material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole, poly(N,N'bis( 4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-benzenedi amine), 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl-N,N '-Bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1 , one or more of 1'-biphenyl-4,4'-diamine.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic flow diagram of a preparation method of a nanocomposite material provided by an embodiment of the present application;

Fig. 2 is a light-emitting device with a positive structure provided in the first embodiment of the present application;

Fig. 3 is a light-emitting device with a positive structure provided in the second embodiment of the present application;

Fig. 4 is a light-emitting device with an inverted structure provided by the third embodiment of the present application;

Fig. 5 is the TEM electron microscope picture of a kind of nanocomposite material provided by the embodiment of the present application;

6 is a schematic flow diagram of a method for preparing a nanocomposite provided in another embodiment of the present application;

Fig. 7 is a schematic flowchart of a method for preparing a nanocomposite material provided by another embodiment of the present application.

Explanation of reference signs:

Substrate: 1; anode: 2; hole injection layer: 3; hole transport layer: 4; light emitting layer: 5; electron transport layer: 6; cathode: 7.

Embodiment of this application

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

It should be noted that the description sequence of the following embodiments is not intended to limit the preferred sequence of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to".

Various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the application; therefore, the described range should be regarded as The description has specifically disclosed all possible subranges as well as individual values within that range. For example, a description of a range from 1 to 6 should be considered to have specifically disclosed subranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and Single numbers within the stated ranges, eg 1, 2, 3, 4, 5 and 6, apply regardless of the range. Additionally, whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range.

In this application, "one or more" means one or more, and "multiple" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one item (unit) of a, b, or c", or "at least one item (unit) of a, b, and c" can mean: a, b, c, a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

First, an embodiment of the present application provides a nanocomposite material, including: a metal oxide nanocore, and a conductive polymer shell covering the metal oxide nanocore.

Experiments have found that the main reason for the low luminous efficiency of the device is the limitation of material properties. The hole injection performance often cannot match the electron injection, resulting in an imbalance in hole-electron transport, and the phenomenon of electron accumulation in the light-emitting layer. It may be recombined in the hole transport layer, and the luminous efficiency of the device will be affected. In addition, experiments have also found that the more commonly used method for preparing cathodes for light-emitting devices is magnetron sputtering, but the energy of magnetron sputtering is relatively high, and the process of sputtering cathodes will cause bombardment damage to the electron transport layer, resulting in device damage. The problem of leakage current.

In the embodiment of the present application, a nanocomposite material is obtained by coating the surface of oxide nanoparticles with a conductive polymer. When the nanocomposite material is used as the electron transport layer of a light-emitting device, the mobility of electrons can be reduced, thereby helping electrons The balance of electrons and holes helps electrons and holes to recombine in the light-emitting layer, improving the luminous efficiency of the device and improving the performance of the device. In addition, as a protective layer, the conductive polymer coated on the metal oxide nano-core can absorb the high-energy particles brought by sputtering to a certain extent, thereby preventing damage to the electron transport layer during sputtering cathode and improving device leakage. current problem.

In some embodiments, the conductive polymer is one or more of poly-1,5-diaminoanthraquinone, polyaniline, poly(1-aminoanthraquinone) or poly(2-aminoanthraquinone). Further, the poly 1,5-diaminoanthraquinone (PDAA) material has better electrical compatibility, that is, the matching degree of electroluminescence and quantum dots is better, so the performance of the device is improved better; in addition, The poly-1,5-diaminoanthraquinone coated on the metal oxide nano-core has a dense stacking structure, which can better absorb the high-energy particles brought by sputtering as a protective layer, thereby preventing electrons from being damaged during the sputtering cathode process. The damage of the transmission layer and the improvement effect of the leakage current of the device are more significant.

In some embodiments, the thickness of the conductive polymer shell layer is 3nm-5nm (nanometer). If the thickness is too thin, the inner metal oxide nano-core cannot be well protected; if it is too thick, the performance of the device will be affected. It can be understood that the thickness of the conductive polymer shell layer can be any value within the range of 3nm to 5nm, for example: 3nm, 3.5nm, 4nm, 4.5nm, 5nm, etc., or other unlisted values within the range of 3nm to 5nm out the value.

In some embodiments, the particle size of the metal oxide nano-core is 7nm-10nm. If the particle size of the metal oxide nano-core is too large, its energy band will be too narrow, and the energy band matching with quantum dots will become poor; if the particle size is too small, it will easily agglomerate during the preparation process, resulting in poor stability. It can be understood that the particle size of the metal oxide nano-core can be any value within the range of 7nm-10nm, for example: 7nm, 7.5nm, 8nm, 8.5nm, 9nm, 9.5nm, 10nm and so on. Or other unlisted values within the range of 7nm to 10nm.

In some embodiments, the particle size of the nanocomposite material is 10nm-15nm. In this thickness range, the performance of the device is better. It can be understood that the particle size of the nanocomposite material can be 10nm, 10.5nm, 11nm, 11.5nm, 12nm, 12.5nm, 13nm, 13.5nm, 14nm, 14.5nm, 15nm, etc., or within the range of 10nm to 15nm Other values not listed.

In some embodiments, the metal oxide may be a doped or non-doped metal oxide known in the art as an electron transport material. For example, in some specific embodiments, the doped or non-doped metal oxide is selected from but not limited to: ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO , ZnSnO, ZnLiO or one or more of InSnO. In some embodiments, the metal oxide is doped or non-doped ZnO, and ZnO is an excellent semiconductor material, a good electron transport layer material, and has strong electron injection performance. Coating ZnO with conductive polymer has a significant effect on improving the hole-electron transport imbalance.

In some embodiments, the nanocomposite material is composed of a metal oxide nanocore, and a conductive polymer shell covering the metal oxide nanocore.

Correspondingly, as shown in Figure 1, the embodiment of the present application also provides a method for preparing a nanocomposite material, the method comprising:

S10. providing a sol containing metal oxide nanoparticles; and

S20. Add a conductive polymer monomer and an oxidant to the sol containing metal oxide nanoparticles, and perform a polymerization reaction to obtain a nanocomposite material, wherein the nanocomposite material includes a metal oxide nanocore, and a coating The conductive polymer shell of the metal oxide nanocore.

In the method provided in the embodiment of the present application, by adding a conductive polymer monomer (such as 1,5-diaminoanthraquinone) and an oxidizing agent to the sol containing metal oxide nanoparticles, the conductive polymer monomer can undergo oxidative polymerization reaction, Thereby, a conductive polymer (such as poly 1,5-diaminoanthraquinone) is generated and covered on the surface of the oxide nanoparticle to obtain a nanocomposite material. When the nanomaterial is used as an electron transport layer of a light-emitting device, it can Reduce electron mobility, thereby helping the balance of electrons and holes, improving the luminous efficiency of the device, and improving the performance of the device. In addition, the conductive polymer can be used as a protective layer to prevent damage to the electron transport layer during sputtering of the cathode and improve the leakage current of the device.

In some embodiments, the conductive polymer monomer is one or more of 1,5-diaminoanthraquinone, aniline, 1-aminoanthraquinone or 2-aminoanthraquinone.

Please refer to Figure 7, in some embodiments, the step S10 provides a sol containing metal oxide nanoparticles, including:

S11. Mix the deionized water or ethylene glycol solution of the precipitating agent with the salt evenly, then hydrothermally react at 120°C-180°C for 5h-10h, filter the product after cooling to room temperature, and wash with water and ethanol several times respectively, Then it is dried to obtain metal oxide nanoparticles.

S12. Add the above-mentioned metal oxide nanoparticles into the aqueous solution of the surfactant, and disperse ultrasonically for 5 minutes to 30 minutes to form a stable dispersed metal oxide nanoparticle sol.

In some embodiments, the molar ratio of the precipitation agent to the salt is (1-2):6.

In some embodiments, the molar ratio of the surfactant to the metal oxide nanoparticles is 1:4.

In some embodiments, the salt may be a zinc salt, including but not limited to: one or more of zinc acetate, zinc citrate, and zinc lactate.

In some embodiments, the precipitating agent is one or more of urea, hexamethylenetetramine, tetramethylammonium hydroxide or sodium hydroxide.

In some embodiments, the surfactant is selected from one or more of sodium dodecylsulfonate, sodium laurate or polyethylene glycol.

Please refer to FIG. 6, in some embodiments, the step S20 adds a conductive polymer monomer and an oxidant to the sol containing metal oxide nanoparticles, and performs a polymerization reaction to obtain a nanocomposite material, including:

S21. Add conductive polymer monomers to the sol containing oxide nanoparticles, and perform ultrasonic dispersion treatment to obtain an intermediate mixed solution.

S22. Add an oxidizing agent to the intermediate mixed solution and mix to carry out a polymerization reaction to obtain the nanocomposite material.

In some embodiments, after the nanocomposite material is obtained, a washing step is also included, and the washing step can be performed in conjunction with suction filtration. The purpose of washing is to remove unreacted reactants or impurities, such as oxidants. Organic matter and water can be used for washing, such as deionized water and methanol for washing.

In some embodiments, the molar ratio of the conductive polymer monomer to the metal oxide nanoparticles is (1˜5):20. If the conductive polymer monomer is too small, the metal oxide nanoparticles cannot be completely coated; if too much, the coating thickness is too thick and the device performance will be affected. It can be understood that the molar ratio of the conductive polymer monomer to the metal oxide nanoparticles is any value within the range of (1-5):20, such as 1:20, 2:20, 3:20, 4: 20, 5:20, etc., or other unlisted values within the range of (1~5):20.

In some embodiments, the molar ratio of the oxidizing agent to the conductive polymer monomer is (1˜2):2. If there is too little oxidizing agent, the conductive polymer monomer cannot be completely polymerized; if there is too much oxidizing agent, too much oxidizing agent will be introduced into the solution, which will affect the later washing. It can be understood that the molar ratio of the oxidizing agent to the conductive polymer monomer can be any value within the range of (1-2):2, for example: 1:2, 1.1:2, 1.2:2, 1.3:2, 1.4: 2, 1.5: 2, 1.6: 2, 1.7: 2, 1.8: 2, 1.9; 2, 2: 2, etc., or other unlisted values within the range of (1～2): 2.

In some embodiments, the oxidizing agent is selected from one or more of ammonium persulfate or hydrogen peroxide.

In some embodiments, the metal oxide nanoparticle sol includes the metal oxide nanoparticles, a surfactant and water, and the surfactant is selected from sodium dodecylsulfonate, sodium laurate, or polyethylene glycol. One or more of diols.

In some embodiments, when the conductive polymer monomer is 1,5-diaminoanthraquinone, the mixing treatment time is 5h-10h (hours), and the mixing temperature is 3°C-10°C (degrees Celsius ), because the oxidative polymerization of the conductive polymer monomer is an exothermic reaction, so it needs to be carried out at a lower temperature, if the temperature is too low, the reaction rate is too slow; if the temperature is too high, the synthetic conductive polymer monomer The surface is rough and there are many defects, which affect the performance of the device. It can be understood that the mixing temperature can be any value in the range of 3°C to 10°C, such as 3°C, 4°C, 5°C, 6°C, 7°C ℃, 8℃, 9℃, 10℃, or other unlisted values within the range of 3℃～10℃. When the conductive polymer monomer is aniline, 1-aminoanthraquinone or 2-aminoanthraquinone, the mixing treatment time and mixing temperature are not particularly limited, as long as the required nanocomposite material is formed.

In some embodiments, the time for the ultrasonic dispersion treatment is 5 minutes to 30 minutes (minutes). The purpose of ultrasonic dispersion is to uniformly disperse the conductive polymer in the sol of oxide nanoparticles. It can be understood that the time of ultrasonic dispersion can be arbitrarily selected within the range of 5min to 30min, such as 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min, 30min, etc., or 5min Other values not listed within the range of ~30min.

For a better understanding, taking zinc oxide and 1,5-diaminoanthraquinone as examples, the following are specific examples of the preparation method of nanocomposites:

(1) Mix the deionized water or ethylene glycol solution of the precipitant with the zinc salt evenly, the molar ratio of the precipitant to the zinc salt is (1~2):6, and then react hydrothermally at 120°C~180°C for 5h ~10h; the product is cooled to room temperature, filtered, washed with water and ethanol three times, and then dried to obtain nano-spherical zinc oxide.

(2) Add the above-mentioned nano-spherical zinc oxide into the aqueous solution of the surfactant, and ultrasonically disperse the surfactant and the nano-spherical zinc oxide at a molar ratio of 1:4 for 5 minutes to 30 minutes to form a stable dispersed zinc oxide sol.

(3) Control the molar ratio of 1,5-diaminoanthraquinone to nano-zinc oxide to (1~5):20, dissolve 1,5-diaminoanthraquinone monomer in deionized water, and then add it to zinc oxide In the sol, ultrasonically disperse for 10min to 30min.

(4) Add an oxidizing agent under continuous stirring to carry out the polymerization reaction. The molar ratio of the oxidizing agent and 1,5-diaminoanthraquinone is (1-2): 2. After stirring and reacting at a temperature of 3°C-10°C for 5h-10h, Repeated washing with deionized water and methanol for 5 times respectively to obtain a nanocomposite material of zinc oxide coated with poly-1,5-diaminoanthraquinone, and then dispersed in ethanol solution for use.

As shown in Figures 2 to 4, the present application also provides a light-emitting device, including: a cathode 7, an anode 2, and an electron transport layer 6 and a light-emitting layer 5 arranged between the cathode 7 and the anode 2, the light-emitting Layer 5 is disposed close to the anode 2, the electron transport layer 6 is disposed close to the cathode 7, and the material of the electron transport layer 6 includes the nanocomposite material described in any of the above embodiments, or includes any of the above Nanocomposites made by the method described.

In some specific embodiments, the light emitting device is a quantum dot light emitting device (QLED).

The light-emitting device described in the embodiments of the present application may have a positive structure or an inverse structure. In the light-emitting device, the side of the cathode 7 or the anode 2 away from the light-emitting layer 5 also includes the substrate 1, the anode 2 is arranged on the substrate 1 in the positive structure, and the cathode 7 is arranged on the substrate 1 in the inverse structure superior. A hole functional layer such as a hole transport layer 4 and a hole injection layer 3 may also be provided between the anode 2 and the light emitting layer 5 . For example:

Fig. 3 shows a schematic diagram of a positive structure of the light-emitting device described in the embodiment of the present application. As shown in Fig. 3, the device of the positive structure includes a substrate 1 and an anode 2 arranged on the surface of the substrate 1 , the hole injection layer 3 arranged on the surface of the anode 2, the hole transport layer 4 arranged on the surface of the hole injection layer 3, the light emitting layer 5 arranged on the surface of the hole transport layer 4, and the The electron transport layer 6 on the surface of the light-emitting layer 5 and the cathode 7 disposed on the surface of the electron transport layer 6, wherein the material of the electron transport layer 6 is selected from nanocomposite materials.

Fig. 4 shows a schematic diagram of an inverse structure of the light emitting device according to the embodiment of the present application. As shown in Fig. 4, the inversion structure light emitting device includes a substrate 1 and a cathode 7 arranged on the surface of the substrate 1 , the electron transport layer 6 arranged on the surface of the cathode 7, the light emitting layer 5 arranged on the surface of the electron transport layer 6, the hole transport layer 4 arranged on the surface of the light emitting layer 5 and the hole transport layer 4 arranged on the surface of the hole transport The hole injection layer 3 and the anode 2 on the surface of the layer 4, wherein the material of the electron transport layer 6 is selected from nanocomposite materials.

In each embodiment of the present application, the material of each functional layer may be the following materials, for example:

The substrate 1 can be a rigid substrate or a flexible substrate. Specific materials may include one of glass, silicon wafer, polycarbonate, polymethylmethacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone or more.

The anode 2 is selected from one or more of indium-doped tin oxide, fluorine-doped tin oxide, tin-doped zinc oxide or indium-doped zinc oxide.

The material of the hole injection layer 3 is selected from PEDOT:PSS, or other materials with good hole injection properties, such as one or more of NiO, MoO ₃ , WO ₃ or V ₂ O ₅ .

The material of the hole transport layer 4 is selected from but not limited to poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) (TFB), polyvinylcarbazole (PVK), poly (N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine)(Poly-TPD), poly(9,9-dioctylfluorene-co-bis-N , N-phenyl-1,4-phenylenediamine) (PFB), 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA), 4,4'-bis(9- Carbazole)biphenyl (CBP), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD ), one or more of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), or Is other high performance hole transport material.

The material of the light-emitting layer 5 includes quantum dots, the quantum dots are selected from one or more of II-VI group compounds, III-V group compounds and I-III-VI group compounds, and the II-VI group The compound is selected from one or more of CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS; CdZnSeS, CdZnSeTe or CdZnSTe; The III-V group compound is selected from one or more of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP or InAlNP; the I-III-VI group compound is selected from CuInS _2. One or more of CuInSe ₂ or AgInS ₂ .

The cathode 7 is selected from one or more of Al, Cu, Mo, Au, Ag or MoO ₃ .

In some embodiments, the cathode is the cathode 7 prepared by magnetron sputtering.

In some embodiments, the thickness of the electron transport layer is 15-30nm. If the electron transport layer is too thin, the sputtering damage may pass through the electron transport layer and damage the light-emitting layer. If the electron transport layer is too thick, it will cause The resistance of the device increases, which reduces the performance of the device. It can be understood that the thickness of the electron transport layer can be arbitrarily selected within the range of 15nm to 30nm, such as 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, etc., or any other unlisted value within the range of 15nm to 30nm.

Correspondingly, the present application also provides a method for preparing a light-emitting device. Specifically, the light-emitting device may be a light-emitting device with a positive structure or a light-emitting device with an inverse structure. Specifically, the method for preparing a light-emitting device with a positive structure Including the following steps:

(1) Deposit a light-emitting layer on the anode substrate.

(2) Depositing an electron transport layer on the light-emitting layer using a solution of the electron transport layer material.

(3) preparing a cathode on the electron transport layer to obtain the light-emitting device.

A method for preparing a light-emitting device with an inverted structure includes the following steps:

(1) An electron transport layer is deposited on the cathode using a solution of the electron transport layer material.

(2) A light emitting layer is deposited on the electron transport layer.

(3) preparing an anode on the light-emitting layer to obtain the light-emitting device.

The solution of the material for the electron transport layer includes nanocomposite materials and an organic solvent, and the organic solvent may be an alcohol compound, such as ethanol. The nano-composite material includes: a metal oxide nano-core, and a conductive polymer shell covering the metal oxide nano-core. The nano-composite material and its preparation method have been described in detail in the previous embodiment. Here I won't go into details here.

Regardless of whether it is a positive or reverse device, in this application, the method for preparing each functional layer on the light-emitting device can be realized by methods known in the art, such as chemical methods and physical methods, wherein chemical methods include: chemical vapor phase Deposition method, continuous ion layer adsorption and reaction method, anodic oxidation method, electrolytic deposition method, co-precipitation method. Physical methods include physical coating methods and solution processing methods. Specific physical coating methods include: thermal evaporation coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion coating method, physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc. Solution processing methods include spin coating method, printing method, inkjet printing method, blade coating method, printing method, dipping method, soaking method, spraying method, roller coating method, casting method, slit coating method, strip coating method coating method.

For example, in some specific embodiments, each functional layer on the light-emitting device is prepared by the spin-coating method in the solution method, and the preparation by the spin-coating method needs to prepare the solution of each functional layer material first, and then spin The coated sheet is placed on a spin coater, and the solution configured with functional layer materials is dropped onto the top of the spin coater, spin-coated at a preset speed, and the preparation of the functional layer is completed after heat treatment. The spin coating method has the characteristics of mild process conditions, simple operation, energy saving and environmental protection, and its preparation of light-emitting devices has the advantages of high carrier mobility and precise thickness.

In order to better understand this application, the following are the specific steps for preparing each functional layer by using the spin-coating method, taking a positive light-emitting device as an example:

First, make an anode on the substrate, and then spin-coat a layer of hole injection layer on the surface of the treated substrate; place the substrate with the spin-coated hole injection layer in a nitrogen atmosphere, and spin-coat a hole injection layer on the surface of the hole injection layer. A layer of hole transport layer; then, a light-emitting layer is spin-coated on the hole-transport layer; a nanocomposite material is spin-coated on the light-emitting layer as an electron transport layer; finally, electrons are spin-coated by magnetron sputtering A layer of cathode is sputtered on the substrate of the transport layer to obtain a light emitting device.

The preparation method of the reverse type light emitting device is similar to that of the positive type, the difference is only in the deposition sequence of the functional layers, which will not be repeated here.

The present application will be described in detail below through examples.

Example 1

This embodiment provides a nanocomposite material and a light emitting device.

The preparation steps of this nanocomposite material are as follows:

Dissolve 200mg of zinc acetate in 50mL of deionized water, and dissolve another 70mg of hexamethylenetetramine in 50mL of deionized water, mix the above two solutions, stir for 5 minutes, then transfer to a 200m1 hydrothermal reaction kettle, keep the water The thermal reaction temperature is 160°C. After 8 hours of reaction, it is naturally cooled, taken out for suction filtration, washed with deionized water and ethanol for several times, and then dried to obtain nano-spherical zinc oxide particles. Dissolve 84mg of sodium dodecylsulfonate in 50mL of deionized water, add another 100mg of nano-zinc oxide to the above solution, stir ultrasonically for 10 minutes to form a stable dispersed nano-sol of zinc oxide, and place the above-mentioned sol in a 5°C incubator , continue to stir, add 15mg of PDAA monomer, stir for 30 minutes to fully dissolve it, take another 10mg of ammonium persulfate and dissolve it in 10mL of deionized water, add the ammonium persulfate solution dropwise to the nano-zinc oxide sol containing PDAA monomer, After the addition was completed, the stirring reaction was continued for 8 hours. After the reaction was completed, repeated suction filtration and washing were performed with deionized water and methanol to obtain a nanocomposite material of zinc oxide nano-cores coated with poly-1,5-diaminoanthraquinone shells. And dispersed in ethanol solution and reserved for later use.

After being detected by a particle size detector, the particle size of the nanocomposite material is 10nm-15nm, and the TEM image is shown in Figure 5, indicating that the nanocomposite material was successfully prepared. The particle diameters and electron micrographs of other examples are roughly the same as those of this example.

The preparation method of the light-emitting device is as follows:

(1) First, place the patterned ITO substrate (including the anode and the substrate) in acetone, lotion, deionized water and isopropanol in order for ultrasonic cleaning, and each step of ultrasonic cleaning needs to last for about 15 minutes. After the ultrasound is completed, place the ITO substrate in a clean oven to dry for later use.

(2) After the ITO substrate is dried, treat the surface of the ITO substrate with UV-ozone for 5 minutes to further remove the organic matter attached to the surface of the ITO substrate and improve the work function of the ITO.

(3) Deposit a layer of PEDOT:PSS on the surface of the treated ITO substrate as a hole injection layer. Done in the air.

(4) Place the dried ITO substrate coated with the hole injection layer in a nitrogen atmosphere to deposit a hole transport layer TFB with a thickness of 30nm, and place it on a heating platform at 150°C for heating 30 min to remove solvent.

(5) After the sheet treated in the previous step is cooled, deposit the luminescent layer on the TFB layer with a thickness of 30 nm. After the deposition of this step is completed, place the sheet on a heating platform at 100° C. for 10 minutes to remove residual solvent.

(6) After cooling the sheet treated in the previous step, deposit 30nm nanocomposite material on the light-emitting layer as the electron transport layer, and anneal at 80°C for 30min on the heating plate.

(7) The Ag electrode with a thickness of 80nm is deposited on the electron transport layer by magnetron sputtering; the light-emitting device is obtained by simply encapsulating it with an ultraviolet curing adhesive.

Example 2

This embodiment provides a nanocomposite material and a light emitting device.

The preparation steps of this nanocomposite material are as follows:

Dissolve 400mg of zinc acetate in 50mL of deionized water, and dissolve another 70mg of hexamethylenetetramine in 50mL of deionized water, mix the above two solutions, stir for 5 minutes, then transfer to a 200mL hydrothermal reaction kettle, keep the water The thermal reaction temperature is 160°C. After 8 hours of reaction, it is naturally cooled, taken out for suction filtration, washed with deionized water and ethanol for several times, and then dried to obtain nano-spherical zinc oxide particles. Take 100mg of nano-zinc oxide and add 40mL of polyethylene glycol, and stir ultrasonically for 10 minutes to make the zinc oxide form a stable and dispersed nano-sol. Dissolve another 30 mg of ammonium persulfate in 10 mL of deionized water, add the ammonium persulfate solution dropwise to the nano-zinc oxide sol containing PDAA monomer, continue to stir and react for 8 hours after the addition, and use deionized Water and methanol are subjected to repeated suction filtration and washing to obtain a nanocomposite material of zinc oxide nano-cores coated with poly-1,5-diaminoanthraquinone shells, which is then dispersed in ethanol solution.

The preparation method of the light-emitting device is the same as that of Example 1.

Example 3

This embodiment provides a nanocomposite material and a light emitting device.

The preparation steps of nanocomposites are as follows:

Dissolve 300mg of zinc acetate in 50mL of deionized water, and another 40mg of tetramethylammonium hydroxide in 50m1 of deionized water, mix the above two solutions, stir for 5 minutes, then transfer to a 200m1 hydrothermal reaction kettle, keep the water The thermal reaction temperature is 160°C. After 8 hours of reaction, it is naturally cooled, taken out for suction filtration, washed with deionized water and ethanol for several times, and then dried to obtain nano-spherical zinc oxide particles. Dissolve 84mg of sodium dodecylsulfonate in 50mL of deionized water, add another 100mg of nano-zinc oxide to the above solution, stir ultrasonically for 10 minutes to form a stable dispersed nano-sol of zinc oxide, and place the above-mentioned sol in a 5°C incubator , continue to stir, add 50mg of PDAA monomer, stir for 30 minutes to fully dissolve it, take another 30mg of ammonium persulfate and dissolve it in 10mL of deionized water, add the ammonium persulfate solution dropwise to the nano-zinc oxide sol containing PDAA monomer, After the addition was completed, the stirring reaction was continued for 8 hours. After the reaction was completed, repeated suction filtration and washing were performed with deionized water and methanol to obtain a nanocomposite material of zinc oxide nano-cores coated with poly-1,5-diaminoanthraquinone shells. And dispersed in ethanol solution.

The preparation method of the light-emitting device is the same as that of Example 1.

Example 4

This embodiment provides a nanocomposite material and a light emitting device.

The preparation method of the nanocomposite is the same as that of Example 1.

The preparation method of this light-emitting device is roughly the same as that of Example 1, except that the thickness of the electron transport layer is 20 nm.

Example 5

This embodiment provides a nanocomposite material and a light emitting device.

The preparation method of the nanocomposite is the same as that of Example 1.

The preparation method of the light-emitting device is roughly the same as that of Example 1, except that the thickness of the electron transport layer in this example is 15 nm.

Example 6

This embodiment provides a nanocomposite material and a light emitting device.

The preparation method of the nanocomposite is the same as that of Example 1.

The preparation method of the light-emitting device is roughly the same as that of Example 1, except that the thickness of the cathode in this example is 100 nm.

Example 7

This embodiment provides a nanocomposite material and a light emitting device.

The preparation method of the nanocomposite is the same as that of Example 1.

The preparation method of this light-emitting device is roughly the same as that of Example 1, except that the thickness of the cathode in this example is 120 nm.

Comparative example 1

This comparative example provides a light-emitting device, which differs from that of Example 1 only in that the electron transport material of this comparative example is ZnO.

Verification example

The verification example is used to verify the performance of the light-emitting devices provided in Examples 1-7 and Comparative Example 1.

The light-emitting devices prepared in the above examples were tested for the efficiency and current density of the external quantum dots by conventional methods in the art, and the test results are shown in Table 1.

Table 1

As shown in Table 1, comparing Examples 1 to 7 with Comparative Example 1, the efficiency of the devices of Examples 1 to 7 is significantly better than that of Comparative Example 1, indicating that the zinc oxide nano-nucleus coated with PDAA is applied to the electronic components of the device. After the transport layer, the performance of the device is significantly improved, which is due to the PDAA coating the zinc oxide nano-core, which can reduce the mobility of electrons, thereby helping the balance of electrons and holes.

Generally speaking, the larger the current density value under the IV voltage, the more serious the leakage of the device, and the leakage of the device is mainly the leakage of the electron transport layer, so the lower the value of the current density at 1V, the smaller the damage of the electron transport layer. The current densities of the devices of Examples 1 to 7 are significantly lower than those of Comparative Example 1, indicating that the damage of the electron transport layer of the devices of Examples 1 to 7 is significantly smaller than that of Comparative Example 1. This is because PDAA has a dense stacked structure, and the zinc oxide nano-core The outer coated PDAA layer can absorb the high-energy particles brought by sputtering to a certain extent, thereby reducing the damage caused by sputtering to the electron transport layer.

A kind of nanocomposite material provided by the embodiment of the present application and its preparation method and light-emitting device have been introduced in detail above. The principle and implementation mode of the application have been explained by using specific examples in this paper. The description of the above embodiment is only used To help understand the technical solutions and core ideas of the present application; those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (17)

1. A nanocomposite material, comprising:

   A metal oxide nano core, and a conductive polymer shell covering the metal oxide nano core.
2. The nanocomposite material according to claim 1, wherein the particle size of the nanocomposite material is 10nm-15nm.
3. The nanocomposite material according to claim 1 or 2, wherein the thickness of the conductive polymer shell is 3nm-5nm.
4. The nanocomposite material according to any one of claims 1 to 3, wherein the particle diameter of the metal oxide nano-core is 7nm-10nm.
5. The nanocomposite material according to any one of claims 1 to 4, wherein the conductive polymer is poly 1,5-diaminoanthraquinone, polyaniline, poly(1-aminoanthraquinone) or poly(2- One or more of aminoanthraquinones).
6. The nanocomposite material according to any one of claims 1 to 5, wherein the metal oxide is selected from the group consisting of: ZnO, TiO ₂ , SnO ₂ , Ta ₂ O ₃ , ZrO ₂ , NiO, TiLiO, ZnAlO, ZnMgO, One or more of ZnSnO, ZnLiO or InSnO.
7. The nanocomposite material according to any one of claims 1 to 6, wherein the nanocomposite material is composed of a metal oxide nanocore and a conductive polymer shell covering the metal oxide nanocore.
8. A method for preparing a nanocomposite, wherein the method comprises:

   providing a sol comprising metal oxide nanoparticles; and

   adding a conductive polymer monomer and an oxidizing agent to the sol containing oxide nanoparticles, and performing a polymerization reaction to obtain the nanocomposite material;

   Wherein, the nano-composite material includes a metal oxide nano-core and a conductive polymer shell covering the metal oxide nano-core.
9. The method according to claim 8, wherein the molar ratio of the conductive polymer monomer to the metal oxide nanoparticles is (1-5):20; and/or

   The molar ratio of the oxidizing agent to the conductive polymer monomer is (1-2):2; and/or

   The oxidant is selected from one or more of ammonium persulfate or hydrogen peroxide; and/or

   The conductive polymer monomer is one or more of 1,5-diaminoanthraquinone, aniline, 1-aminoanthraquinone or 2-aminoanthraquinone; and/or

   The metal oxide nanoparticle sol includes the metal oxide nanoparticles, a surfactant and water, and the surfactant is selected from one of sodium dodecylsulfonate, sodium laurate or polyethylene glycol or more.
10. The method according to claim 8 or 9, wherein, adding a conductive polymer monomer and an oxidizing agent to the sol containing metal oxide nanoparticles, and carrying out a polymerization reaction, to obtain the nanocomposite material, comprising:

    adding a conductive polymer monomer to the sol containing oxide nanoparticles, and ultrasonically dispersing to obtain an intermediate mixed solution;

    The oxidizing agent is added into the intermediate mixed solution and mixed to carry out a polymerization reaction to obtain the nanocomposite material.
11. The method according to claim 10, wherein the conductive polymer monomer is 1,5-diaminoanthraquinone, the mixing treatment time is 5h-10h, and the temperature is 3°C-10°C; and/or

    The time for the ultrasonic dispersion treatment is 5 minutes to 30 minutes.
12. The method according to any one of claims 8 to 11, wherein the step of providing a sol containing metal oxide nanoparticles comprises:

    Mix the deionized water or ethylene glycol solution of the precipitating agent with the salt evenly, then hydrothermally react at 120°C-180°C for 5h-10h, filter the product after cooling to room temperature, and wash with water and ethanol for several times, and then Obtaining metal oxide nanoparticles through drying;

    The metal oxide nanoparticles are added into the aqueous solution of the surfactant, and ultrasonically dispersed for 5 minutes to 30 minutes to form a stably dispersed metal oxide nanoparticle sol.
13. The method according to claim 12, wherein the molar ratio of the precipitation agent to the salt is (1-2):6.
14. The method according to claim 12 or 13, wherein the salt comprises a zinc salt, and the zinc salt comprises one or more of zinc acetate, zinc citrate, and zinc lactate;

    The precipitant is one or more of urea, hexamethylenetetramine, tetramethylammonium hydroxide or sodium hydroxide;

    The surfactant is selected from one or more of sodium dodecylsulfonate, sodium laurate or polyethylene glycol.
15. A light emitting device, comprising:

    Cathode, electron transport layer, light-emitting layer and anode stacked in sequence;

    Wherein, the material of the electron transport layer comprises the nanocomposite material according to any one of claims 1 to 7, or comprises the nanocomposite material produced by the method according to any one of claims 8 to 14.
16. The light emitting device according to claim 15, wherein the material of the anode is selected from one or more of indium-doped tin oxide, fluorine-doped tin oxide, tin-doped zinc oxide or indium-doped zinc oxide; and / or

    The material of the light-emitting layer includes quantum dots, the quantum dots are selected from one or more of II-VI group compounds, III-V group compounds and I-III-VI group compounds, and the II-VI group compounds One or more selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS; CdZnSeS, CdZnSeTe or CdZnSTe; the III -V group compound is selected from one or more of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP or InAlNP; the I-III-VI group compound is selected from CuInS ₂ , CuInSe ₂ or AgInS ₂ or one or more; and/or

    The material of the cathode is selected from one or more of Al, Cu, Mo, Au, Ag or MoO ₃ .
17. The light emitting device according to claim 15 or 16, wherein the light emitting device further comprises a hole transport layer and a hole injection layer, and the hole injection layer is arranged between the anode and the light emitting layer, so The hole transport layer is disposed between the hole injection layer and the light emitting layer;

    The material of the hole injection layer is selected from one or more of PEDOT:PSS, NiO, MoO ₃ , WO ₃ or V ₂ O ₅ ;

    The material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole, poly(N,N'bis( 4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-benzenedi amine), 4,4',4"-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(9-carbazole)biphenyl, N,N'-diphenyl-N,N '-Bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1 , one or more of 1'-biphenyl-4,4'-diamine.

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