Composite material and preparation method thereof, light-emitting device and display device

Abstract

The invention provides a composite material and a preparation method thereof, a light-emitting device and a display device. The composite material comprises inorganic nano-particles and a polymer connected with the inorganic nano-particles, the polymer contains porphyrinyl, and the polymer has the performance of isolating water and oxygen, so that when the polymer is connected with the inorganic nano-particles, the influence of external water and oxygen on the inorganic nano-particles can be weakened or eliminated; therefore, the electrical properties of the inorganic nanoparticles are kept stable, and the porphyrin group in the polymer has conductivity, so that the electron transmission efficiency of the composite material can be improved.

Description

Technical Field

[0001] The present application relates to the field of light-emitting devices, and particularly to a composite material, a preparation method thereof, a light-emitting device, and a display device. Background Art

[0002] Electroluminescent devices include OLED (Organic Light-Emitting Diode) and QLED (Quantum Dot Light Emitting Diodes). QLED has advantages such as high color saturation, wet-processability, and high stability, which has attracted more and more attention in the research of QLED. OLED has been widely used in the fields of display, lighting, and smart wear due to its good self-luminous characteristics, high contrast ratio, fast response, and flexible display.

[0003] Electroluminescent devices generally include film layers such as a cathode, an electron transport layer, a light-emitting layer, and an anode. Since the electron transport performance of the existing electron transport layer is poor, the amount of electrons injected into the light-emitting layer is small, which further leads to the problem of carrier imbalance in the light-emitting layer, resulting in poor electrical performance of the electroluminescent device. Summary of the Invention

[0004] Based on this, embodiments of the present application provide a composite material, a preparation method thereof, a light-emitting device, and a display device. The composite material has a high electron transport efficiency.

[0005] In a first aspect, embodiments of the present application provide a composite material, including inorganic nanoparticles and a polymer connected to the inorganic nanoparticles, wherein the polymer contains a porphyrin group.

[0006] In some embodiments, the polymer is a porphyrin-based conjugated microporous polymer.

[0007] In some embodiments, the porphyrin-based conjugated microporous polymer includes a repeating unit having the structure shown in formula (Ⅰ):

[0008]

[0009]

[0010] In the porphyrin-based conjugated microporous polymer, the repeating number n of the unit shown in formula (Ⅰ) is 2 to 10.

[0011] In some embodiments, the polymer includes micropores, the pore diameter of the micropores is 0.01 nm to 2 nm, and the total volume of the plurality of micropores accounts for 15% to 40% of the volume of the polymer.

[0012] In some embodiments, the inorganic nanoparticles are selected from at least one of metal oxides, doped metal oxides, group II-VI semiconductor materials, group III-V semiconductor materials, and group I-III-VI semiconductor materials; and / or

[0013] The metal oxides are selected from at least one of ZnO, BaO, TiO2, and SnO2; and / or

[0014] The metal oxide in the doped metal oxide is selected from at least one of ZnO, TiO2, and SnO2, and the doping element is selected from at least one of Al, Mg, Li, In, and Ga; and / or

[0015] The group II-VI semiconductor materials are selected from at least one of ZnS, ZnSe, and CdS; and / or

[0016] The group III-V semiconductor materials are selected from at least one of InP and GaP; and / or

[0017] The group I-III-VI semiconductor materials are selected from at least one of CuInS and CuGaS.

[0018] In some embodiments, the mass ratio of the polymer to the inorganic nanoparticles is (1-5):20; and / or

[0019] The composite material further includes a surfactant, the surfactant is at least distributed on the outer surface of the inorganic nanoparticles, and the molar ratio of the surfactant to the inorganic nanoparticles is 1:(2-8).

[0020] In a second aspect, an embodiment of the present application provides a method for preparing a composite material, including:

[0021] Providing a polymer dispersion solution and an inorganic nanoparticle dispersion solution; the polymer dispersion solution includes a first solvent and a polymer dispersed in the first solvent, and the polymer contains a porphyrin group; the inorganic nanoparticle dispersion solution includes a second solvent and inorganic nanoparticles dispersed in the second solvent;

[0022] Mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution to obtain a composite material dispersion solution;

[0023] Performing solid-liquid separation on the composite material dispersion solution to obtain a composite material, the composite material includes a polymer and a plurality of inorganic nanoparticles uniformly dispersed inside the polymer.

[0024] In some embodiments, in the composite material dispersion solution, the mass ratio of the polymer to the inorganic nanoparticles is (1-5):20;

[0025] The mixing of the polymer dispersion solution and the inorganic nanoparticle dispersion solution includes: mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution under the temperature condition of 3°C to 10°C, and stirring and reacting for 5 hours to 10 hours after mixing.

[0026] In some embodiments, the inorganic nanoparticle dispersion solution further includes a surfactant, and the molar ratio of the surfactant to the inorganic nanoparticles is 1:(2 - 8).

[0027] In some embodiments, the providing of the polymer dispersion solution includes: providing a polymer, dissolving the polymer in a first solvent to obtain a polymer dispersion solution; and / or

[0028] The providing of the inorganic nanoparticle dispersion solution includes: providing inorganic nanoparticles, dissolving the inorganic nanoparticles in a second solvent to obtain an inorganic nanoparticle dispersion solution.

[0029] In some embodiments, the polymer is a porphyrin-based conjugated microporous polymer, and the providing of the polymer includes: mixing tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-(dicyclohexylphosphino)-2′,4′,6′-triisopropylbiphenyl, a catalyst, and a third solvent, and reacting at a temperature condition of 100°C to 120°C for 40 hours to 56 hours to obtain a porphyrin-based conjugated microporous polymer; wherein, the molar ratio of tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-(dicyclohexylphosphino)-2′,4′,6′-triisopropylbiphenyl, and the catalyst is 1:(2 - 5):(4 - 6):(0.1 - 0.14):(0.06 - 0.1); and / or

[0030] The inorganic nanoparticles are zinc oxide nanoparticles, and the providing of the inorganic nanoparticles includes: mixing a precipitant solution and a zinc salt solution, and reacting at a temperature condition of 50°C - 70°C for 2 hours to 3 hours to obtain zinc oxide nanoparticles, wherein the molar ratio of the precipitant to the zinc salt is (1 - 2):6.

[0031] In a third aspect, an embodiment of the present application provides a light-emitting device, including a first electrode and a second electrode disposed opposite to each other, and an electron transport layer and a light-emitting layer disposed between the first electrode and the second electrode, wherein the material of the electron transport layer is the composite material as described above or the composite material prepared by the preparation method of the composite material as described above.

[0032] Exemplarily, the light-emitting device further includes a hole transport layer and a hole injection layer;

[0033] When the first electrode is an anode and the second electrode is a cathode, the light-emitting layer, the hole-transporting layer, and the hole-injecting layer are disposed between the electron-transporting layer and the first electrode, and the light-emitting layer, the hole-transporting layer, and the hole-injecting layer are stacked in sequence in the direction from the electron-transporting layer to the first electrode;

[0034] When the first electrode is a cathode and the second electrode is an anode, the light-emitting layer, the hole-transporting layer, and the hole-injecting layer are disposed between the electron-transporting layer and the second electrode, and the light-emitting layer, the hole-transporting layer, and the hole-injecting layer are stacked in sequence in the direction from the electron-transporting layer to the second electrode.

[0035] In some embodiments, the material of the hole-transporting layer includes at least one of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetra[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polysfluorene and its derivatives, polythiophene and its derivatives; and / or

[0036] The material of the hole injection layer includes at least one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and its derivatives, copper phthalocyanine, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, poly(2,3-dihydrothieno[3,4-b][1,4]dioxin), 4,4',4'-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine, tetracyanoquinodimethane, transition metal oxides, and transition metal chalcogenides; and / or

[0037] The first electrode and the second electrode are independently selected from metal oxide electrodes, doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, metal elemental electrodes, or alloy electrodes. The material of the metal oxide electrode includes molybdenum oxide. The material of the doped metal oxide electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, and aluminum-doped magnesium oxide. The composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, or ZnS / Al / ZnS. The material of the metal elemental electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba; and / or

[0038] The materials of the light-emitting layer include organic light-emitting materials or quantum dot light-emitting materials. The organic light-emitting materials include one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4''-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium], diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butyl naphthacene, rubrene derivatives, thermally activated delayed fluorescence materials, exciplex light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;The quantum dot light-emitting material includes at least one of single-structure quantum dots and core-shell structure quantum dots. The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots each include at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.;

[0039] In some embodiments, the thickness of the first electrode is 60 nm - 100 nm, the thickness of the hole injection layer is 10 nm - 50 nm, the thickness of the hole transport layer is 10 nm - 50 nm, the thickness of the light-emitting layer is 20 nm - 60 nm, the thickness of the electron transport layer is 40 nm - 120 nm, and the thickness of the second electrode is 60 nm - 100 nm.

[0040] In a fourth aspect, an embodiment of the present application provides a display device, including the light-emitting device as described above.

[0041] The composite material provided by the embodiment of the present application includes inorganic nanoparticles and a polymer connected to the inorganic nanoparticles. Since the polymer has the property of isolating water and oxygen, when the polymer is connected to the inorganic nanoparticles, the influence of external water and oxygen on the inorganic nanoparticles can be weakened or eliminated, so that the electrical properties of the inorganic nanoparticles remain stable. Since the porphyrin group in the polymer has electrical conductivity, the electron transport efficiency of the composite material can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments.

[0043] Figure 1 It is a flowchart of the preparation method of the composite material provided by the embodiment of the present application.

[0044] Figure 2 It is a first schematic structural diagram of the light-emitting device provided by the embodiment of the present application.

[0045] Figure 3 It is a second schematic structural diagram of the light-emitting device provided by the embodiment of the present application.

[0046] Reference Numerals:

[0047] 100 - Light-emitting device; 10 - First electrode; 20 - Hole injection layer; 30 - Hole transport layer; 40 - Light-emitting layer; 50 - Electron transport layer; 60 - Second electrode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0049] In the present application, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B may be singular or plural.

[0050] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c" can both represent: a, b, c, a + b, a + c, b + c, or a + b + c, where a, b, and c can be single or multiple respectively.

[0051] In this application, forming another layer "on" a certain layer, the so-called "on" is a broad concept, which can mean that the formed another layer is adjacent to a certain layer, or there are other spacer structure layers between another layer and a certain layer. For example, forming a second electrode "on" the first carrier functional layer, the so-called "on" can mean that the formed second electrode is adjacent to the first carrier functional layer, or there are other spacer structure layers between the second electrode and the first carrier functional layer, such as a light-emitting layer.

[0052] Various embodiments of this 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 this application; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0053] Please refer to Figure 1 , an embodiment of this application provides a composite material, including inorganic nanoparticles and a polymer connected to the inorganic nanoparticles, and the polymer contains porphyrin groups.

[0054] Exemplarily, the polymer can coat a partial area or the entire area on the surface of the inorganic nanoparticles, and the ratio between the partial area and the entire area can be 0.1% to 99.9%, such as 0.1%, 0.5%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99.9%, etc.

[0055] Exemplarily, the polymer is a porphyrin-based conjugated microporous polymer.

[0056] It should be noted that the porphyrin-based conjugated microporous polymer is a nitrogen-containing compound with a π-electron conjugated ring structure, which is beneficial to electron transfer. Therefore, it can improve the electron transfer efficiency of the composite material. When the composite material is used in the electron transport layer of a light-emitting device, it can improve the electron transport efficiency of the electron transport layer, thereby improving the electrical performance of the electroluminescent device.

[0057] Exemplarily, the porphyrin-based conjugated microporous polymer includes a repeating unit having the structure shown in formula (I):

[0058]

[0059]

[0060] In the porphyrin-based conjugated microporous polymer, the repeating number n of the unit shown in formula (I) is 2 to 10, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0061] Exemplarily, the preparation method of the porphyrin-based conjugated microporous polymer including the repeating unit having the structure shown in formula (I) may include:

[0062] Under normal temperature and pressure, after mixing tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl, a catalyst and a third solvent, reacting at a temperature of 100 °C to 120 °C (such as 110 °C) for 40 hours to 56 hours, a porphyrin-based conjugated microporous polymer is obtained; wherein, the molar ratio of tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl, and the catalyst is 1:(2 to 5):(4 to 6):(0.1 to 0.14):(0.06 to 0.1). Exemplarily, the catalyst may be a palladium metal catalyst, such as bis(dibenzylideneacetone)palladium, etc. Exemplarily, the third solvent may include at least one of xylene, ethylbenzene, xylene, m-diethylbenzene, and p-diethylbenzene.

[0063] Exemplarily, the polymer includes a plurality of micropores, and the pore diameter of the micropores is 0.01 nm to 2 nm (such as 0.01 nm, 0.03 nm, 0.05 nm, 0.08 nm, 0.1 nm, 0.3 nm, 0.5 nm, 0.8 nm, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm, 2 nm, etc.). The total volume of the plurality of micropores accounts for 15% to 40% (such as 15%, 20%, 25%, 30%, 35%, 40%, etc.) of the volume of the polymer. It should be noted that when the porosity of the polymer (the proportion of the total volume of the plurality of micropores in the volume of the polymer) is higher, the conductivity of the polymer is higher, which helps to improve the electron transport efficiency of the composite material. When the composite material is used as the electron transport layer material of a light-emitting device, it can improve the electron transport efficiency of the electron transport layer, and further improve the electrical performance of the light-emitting device.

[0064] Exemplarily, the inorganic nanoparticles are electron transport materials, and the electron transport materials include at least one of metal oxides, doped metal oxides, group II-VI semiconductor materials, group III-V semiconductor materials, and group I-III-VI semiconductor materials; the metal oxides are selected from at least one of ZnO, BaO, TiO2, and SnO2; the metal oxides in the doped metal oxides are selected from at least one of ZnO, TiO2, and SnO2, and the doping elements are selected from at least one of Al, Mg, Li, In, and Ga; the group II-VI semiconductor materials are selected from at least one of ZnS, ZnSe, and CdS; the group III-V semiconductor materials are selected from at least one of InP and GaP; the group I-III-VI semiconductor materials are selected from at least one of CuInS and CuGaS.

[0065] In some embodiments, the inorganic nanoparticles are zinc oxide nanoparticles.

[0066] Exemplarily, the particle size D50 of the zinc oxide nanoparticles can be 0.1 nm to 6 nm, such as 0.1 nm, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, etc.

[0067] Exemplarily, in the composite material, the mass ratio of the polymer to the inorganic nanoparticles is (1 to 5):20, such as 1:20, 2:20, 3:20, 4:20, 5:20, etc.

[0068] Exemplarily, the composite material further includes a surfactant, and the surfactant is at least distributed on the outer surface of the inorganic nanoparticles. The molar ratio of the surfactant to the inorganic nanoparticles is 1:(2 to 8), such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc.

[0069] It should be noted that the surfactant distributed on the outer surface of the inorganic nanoparticles can change the surface properties of the inorganic nanoparticles, making it easier for the inorganic nanoparticles to adhere to the polymer, that is, making the binding force between the polymer and the inorganic nanoparticles stronger, thereby improving the structural stability of the composite material.

[0070] In some embodiments, a part of the surfactant is distributed on the outer surface of the inorganic nanoparticles, and another part is distributed on the inner surface and / or outer surface of the polymer.

[0071] The composite material provided by the embodiments of the present application includes inorganic nanoparticles and a polymer connected to the inorganic nanoparticles. Since the polymer has the property of isolating water and oxygen, when the polymer is connected to the inorganic nanoparticles, the influence of external water and oxygen on the inorganic nanoparticles can be weakened or eliminated, so that the electrical properties of the inorganic nanoparticles are kept stable. Since the porphyrin group in the polymer has electrical conductivity, the electron transfer efficiency of the composite material can be improved. When the electron transport layer of a light-emitting device adopts this composite material, the electron transfer efficiency of the electron transport layer can be improved, and the electron injection barrier between the electron transport layer and the light-emitting layer can be reduced, which is beneficial to achieving the carrier balance in the light-emitting layer, and further improving the electrical properties of the electroluminescent device.

[0072] It can be understood that, due to the dielectric effect of the polymer itself, the electron injection efficiency of the inorganic nanoparticles can be flexibly adjusted by adjusting the ratio of the polymer to the inorganic nanoparticles. Moreover, due to the confinement effect of the polymer, the inorganic nanoparticles can be evenly dispersed in the polymer and the positions of the inorganic nanoparticles can be kept relatively fixed, so that the problem of uneven film thickness after deposition due to the agglomeration of inorganic nanoparticles can be avoided.

[0073] Please refer to Figure 1 , the embodiments of the present application also provide a preparation method of a composite material, which can be used to prepare the composite material in any of the above embodiments. The preparation method includes:

[0074] S110, providing a polymer dispersion solution and an inorganic nanoparticle dispersion solution; the polymer dispersion solution includes a first solvent and a polymer dispersed in the first solvent, and the polymer contains a porphyrin group; the inorganic nanoparticle dispersion solution includes a second solvent and inorganic nanoparticles dispersed in the second solvent.

[0075] Exemplarily, the providing of the polymer dispersion solution includes: providing a polymer, dissolving the polymer in the first solvent to obtain a polymer dispersion solution.

[0076] Exemplarily, the polymer is a porphyrin-based conjugated microporous polymer, and the providing of the polymer includes: mixing tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, a catalyst, and a third solvent, and reacting at a temperature of 100°C to 120°C (e.g., 110°C) for 40 hours to 56 hours to obtain the porphyrin-based conjugated microporous polymer; wherein, the molar ratio of tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, and the catalyst is 1:(2 to 5):(4 to 6):(0.1 to 0.14):(0.06 to 0.1). In some embodiments, the molar ratio of tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, and the catalyst is 1:3:5:0.12:0.08. Exemplarily, the catalyst can be a palladium metal catalyst, such as bis(dibenzylideneacetone)palladium, etc. Exemplarily, the third solvent can include at least one of xylene, ethylbenzene, xylene, m-diethylbenzene, and p-diethylbenzene.

[0077] Exemplarily, the providing of the inorganic nanoparticle dispersion solution includes: providing inorganic nanoparticles, and dissolving the inorganic nanoparticles in a second solvent to obtain an inorganic nanoparticle dispersion solution.

[0078] Exemplarily, the inorganic nanoparticles are zinc oxide nanoparticles, and the providing of the inorganic nanoparticles includes: mixing a precipitant solution and a zinc salt solution, and reacting at a temperature of 50°C to 70°C for 2 hours to 3 hours to obtain zinc oxide nanoparticles, wherein the molar ratio of the precipitant to the zinc salt is (1 to 2):6, such as 1:6, 1.5:6, 2:6, etc. Exemplarily, the precipitant includes at least one of hexamethylenetetramine, sodium hydroxide (NaOH), lithium hydroxide (LiOH), potassium hydroxide (KOH), and tetramethylammonium hydroxide.

[0079] Exemplarily, the inorganic nanoparticle dispersion solution further includes a surfactant, and the molar ratio of the surfactant to the inorganic nanoparticles is 1:(2 to 8), such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc.

[0080] Exemplarily, the first solvent can include at least one of ethanol, toluene, chlorobenzene, methanol, butanol, and anisole.

[0081] Exemplarily, the second solvent can include at least one of ethanol, methanol, butanol, isopropanol, acetonitrile, and ethylene glycol methyl ether.

[0082] Exemplarily, the providing of the polymer dispersion solution includes: dissolving the polymer in the first solvent and ultrasonically dispersing for 10 minutes to 30 minutes (e.g., 20 minutes) to obtain a polymer dispersion solution.

[0083] Exemplarily, the step of providing the inorganic nanoparticle dispersion solution includes: dissolving inorganic nanoparticles in a second solvent, and performing ultrasonic dispersion for 5 minutes to 30 minutes (such as 20 minutes) to obtain an inorganic nanoparticle dispersion solution.

[0084] S120. Mix the polymer dispersion solution and the inorganic nanoparticle dispersion solution to obtain a composite material dispersion solution.

[0085] Exemplarily, the step of mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution includes: mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution under a temperature condition of 3°C to 10°C (such as 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, etc.), and performing stirring reaction for 5 hours to 10 hours (such as 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.) after mixing. It can be understood that through stirring, not only can the polymer and the inorganic nanoparticles be uniformly mixed, but also the polymer and the inorganic nanoparticles can be tightly connected, thereby forming a composite material with a stable structure.

[0086] Exemplarily, in the composite material dispersion solution, the mass ratio of the polymer to the inorganic nanoparticles is (1 - 5):20, such as 1:20, 2:20, 3:20, 4:20, 5:20, etc.

[0087] Exemplarily, the concentration of the composite material in the composite material dispersion solution is 15 mg / mL to 30 mg / mL, such as 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, etc.

[0088] S130. Perform solid-liquid separation on the composite material dispersion solution to obtain a composite material, which includes inorganic nanoparticles and a polymer connected to the inorganic nanoparticles.

[0089] Exemplarily, methods such as filtration and suction filtration can be used to perform solid-liquid separation on the composite material dispersion solution.

[0090] Please refer to Figure 2 and Figure 3 , an embodiment of the present application further provides a light-emitting device 100, which includes a first electrode 10 and a second electrode 60 arranged oppositely, and an electron transport layer 50 and a light-emitting layer 40 arranged between the first electrode 10 and the second electrode 60. The material of the electron transport layer 50 is the composite material in any of the above embodiments or the composite material prepared by the preparation method of the composite material in any of the above embodiments.

[0091] Please refer to Figure 2 and Figure 3 , the light-emitting device 100 further includes a hole transport layer 30 and a hole injection layer 20.

[0092] Please refer to Figure 2 When the first electrode 10 is an anode and the second electrode 60 is a cathode, the light-emitting layer 40, the hole transport layer 30, and the hole injection layer 20 are disposed between the electron transport layer 50 and the first electrode 10, and the light-emitting layer 40, the hole transport layer 30, and the hole injection layer 20 are sequentially stacked in the direction from the electron transport layer 50 to the first electrode 10.

[0093] Please refer to Figure 3 When the first electrode 10 is a cathode and the second electrode 60 is an anode, the light-emitting layer 40, the hole transport layer 30, and the hole injection layer 20 are disposed between the electron transport layer 50 and the second electrode 60, and the light-emitting layer 40, the hole transport layer 30, and the hole injection layer 20 are sequentially stacked in the direction from the electron transport layer 50 to the second electrode 60.

[0094] Exemplarily, the materials of the hole transport layer 30 include at least one of 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (Poly-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), poly(phenylenevinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MOMO-PPV), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-omeTAD), 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), 1,3-bis(carbazol-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-phenylenevinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polysfluorene and its derivatives, polythiophene (TPH) and its derivatives.

[0095] Exemplarily, the material of the hole injection layer 20 includes at least one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), copper phthalocyanine (CuPc), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), poly(2,3-dihydrothieno[3,4-b][1,4]dioxin) (PEDOT), a derivative of PEDOT:PSS doped with MoO3 (PEDOT:PSS-MoO3), 4,4',4'-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine (m-MTDATA), tetracyanoquinodimethane (F4-TCNQ), transition metal oxides, and transition metal chalcogenides. Exemplarily, the transition metal oxide may include MoO x 、VO x 、WO x 、CrO x 、one or more of CuO. Exemplarily, the metal chalcogenide may include one or more of MoS2, MoSe2, WS2, WSe2, CuS.

[0096] Exemplarily, the first electrode 10 and the second electrode 60 can each independently be selected from a metal oxide electrode, a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal elemental electrode, or an alloy electrode. The material of the metal oxide electrode can be molybdenum oxide (MoO3), and the material of the doped metal oxide electrode can include, but is not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. The composite electrode is an electrode formed by laminating two or more layers of conductive materials, such as AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc., where " / " represents a laminated structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer, and an AZO layer laminated in sequence. The material of the metal elemental electrode can include, but is not limited to, one or more of silver (Ag), magnesium (Mg), aluminum (Al), gold (Au), gallium (Ga), nickel (Ni), platinum (Pt), iridium (Ir), copper (Cu), molybdenum (Mo), calcium (Ca), and barium (Ba). The alloy electrode includes, but is not limited to, an Au:Mg alloy electrode or an Ag:Mg alloy electrode.

[0097] In some embodiments, one of the first electrode 10 and the second electrode 60 that serves as the anode can be an electrode with a relatively high work function, such as, but not limited to, one or more of a doped metal oxide electrode with a relatively high work function, a metal elemental electrode with a relatively high work function, and a carbon nanotube electrode; the material of the metal elemental electrode with a relatively high work function can be Ni, Pt, Au, Ag, Ir, etc.

[0098] In some embodiments, one of the first electrode 10 and the second electrode 60 that serves as the cathode can be an electrode with a relatively low work function. For example, it can include, but is not limited to, a simple metal electrode with a relatively low work function, a composite electrode with a relatively low work function, and an alloy electrode with a relatively low work function. The material of the simple metal electrode with a relatively low work function can be Ca, Ba, Al, Mg, etc. The structure of the composite electrode with a relatively low work function can be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrode with a relatively low work function can be Au:Mg or Ag:Mg, etc.

[0099] Exemplarily, the material of the light-emitting layer 40 can include an organic light-emitting material or a quantum dot light-emitting material.

[0100] Exemplarily, the organic light-emitting material can include, but is not limited to, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)] (CBP:Ir(mppy)3), 4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium] (TCTX:Ir(mmpy)), diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butylperylene (TBPe), rubrene derivatives (TBRb), thermally activated delayed fluorescence (TADF) materials, luminescent materials with characteristics of hybrid local-charge transfer (HLCT) excited states, exciplex luminescent materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives, or one or more of them.

[0101] Exemplarily, the quantum dot light-emitting material includes at least one of a single-structure quantum dot and a core-shell structure quantum dot. Specifically, the material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell material of the core-shell structure quantum dot may each include at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.

[0102] Exemplarily, the thickness of the first electrode 10 is 60 nm - 100 nm, such as 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, etc.

[0103] Exemplarily, the thickness of the hole injection layer 20 is 10 nm - 50 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.

[0104] Exemplarily, the thickness of the hole transport layer 30 is 10 nm - 50 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.

[0105] Exemplarily, the thickness of the light-emitting layer 40 is 20 nm - 60 nm, such as 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, etc.

[0106] Exemplarily, the thickness of the electron transport layer 50 is 40 nm - 120 nm, such as 40 nm, 60 nm, 80 nm, 100 nm, 120 nm, etc.

[0107] Exemplarily, the thickness of the second electrode 60 is 60 nm - 100 nm, such as 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, etc.

[0108] Please refer to Figure 2 and Figure 3 , The embodiment of the present application further provides a method for manufacturing a light-emitting device, which can be used to manufacture the light-emitting device 100 in any of the above embodiments. The manufacturing method includes:

[0109] S210, providing a preform of the light-emitting device, where the preform of the light-emitting device includes the first electrode 10.

[0110] S220, forming an electron transport layer 50 on the preform of the light-emitting device, and the material of the electron transport layer 50 includes the above composite material.

[0111] Exemplarily, forming the electron transport layer 50 on the preform of the light-emitting device includes:

[0112] Providing a polymer dispersion solution and an inorganic nanoparticle dispersion solution; the polymer dispersion solution includes a first solvent and a polymer dispersed in the first solvent, and the polymer contains a porphyrin group; the inorganic nanoparticle dispersion solution includes a second solvent and inorganic nanoparticles dispersed in the second solvent;

[0113] Mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution to obtain a composite material dispersion solution;

[0114] Applying the composite material dispersion solution to the preform of the light-emitting device to obtain a wet film layer, and annealing the wet film layer to obtain the electron transport layer 50.

[0115] Exemplarily, annealing the wet film layer includes: performing heat treatment on the wet film layer at a temperature of 60 °C to 100 °C (such as 80 °C), and the treatment time is 20 minutes to 40 minutes (such as 20 minutes).

[0116] S230. A second electrode 60 is formed on the electron transport layer 50 to obtain a light-emitting device 100.

[0117] Please refer to Figure 2 , when the first electrode 10 is an anode and the second electrode 60 is a cathode, the light-emitting device preform further includes a hole injection layer 20, a hole transport layer 30, and a light-emitting layer 40 disposed between the first electrode 10 and the electron transport layer 50, and the hole injection layer 20, the hole transport layer 30, and the light-emitting layer 40 are sequentially stacked in the direction from the first electrode 10 to the electron transport layer 50.

[0118] Please refer to Figure 3 , when the first electrode 10 is a cathode and the second electrode 60 is an anode, forming the second electrode 60 on the electron transport layer 50 includes: forming a light-emitting layer 40 on the electron transport layer 50, forming a hole transport layer 30 on the light-emitting layer 40, forming a hole injection layer 20 on the hole transport layer 30, and forming the second electrode 60 on the hole injection layer 20.

[0119] Please combine Figure 2 and Figure 3 , the embodiments of the present application further provide a display device, including the light-emitting device in any of the above embodiments or the light-emitting device prepared by the preparation method in any of the above embodiments.

[0120] The composite material, its preparation method, the light-emitting device, and its preparation method of the present application will be described in detail below in the form of specific embodiments.

[0121] Composite Material Example 1

[0122] A composite material, and its preparation method includes:

[0123] Step 11. At normal temperature and pressure, place two monomers, tetrabromophenyl porphyrin (186 mg, 0.2 mmol) and p-phenylenediamine (64.8 mg, 0.6 mmol), in a 50 mL reaction tube, add sodium tert-butoxide (100 mg, 1.04 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (11.44 mg, 0.024 mmol), and bis(dibenzylideneacetone)palladium (9.2 mg, 0.016 mmol). Then, under a nitrogen atmosphere, add 20 mL of anhydrous toluene and react at 110 °C for 48 h. After that, wash and filter the prepared polymer with chloroform, methanol, and water, and place it in a vacuum oven at 100 °C for drying for 48 hours to obtain a porphyrin-based conjugated microporous polymer, and the porphyrin-based conjugated microporous polymer includes repeating units of the structure shown in formula (I):

[0124]

[0125] In the porphyrin-based conjugated microporous polymer, the repeating number n of the unit shown in formula (I) is 5 to 6;

[0126] Step 12: Dissolve 200 mg of zinc acetate in 50 mL of ethanol, and dissolve 70 mg of hexamethylenetetramine in 50 mL of DMSO. Mix the above two solutions, stir for 5 minutes, then transfer them to a 200-mL flask, maintain the hydrothermal reaction temperature at 60 °C, cool naturally after reacting for 2 hours, take out and filter by suction, wash three times with ethanol and n-octane, and then dry to obtain nano-spherical zinc oxide particles;

[0127] Step 13: Dissolve 37 mg of sodium dodecyl sulfate in 50 mL of ethanol, add 100 mg of nano-zinc oxide to the above solution, ultrasonically stir for 10 minutes to form a stable nano-sol dispersion of zinc oxide. Place the nano-sol in an incubator at 5 °C and continuously stir. Add 10 mg of porphyrin-based conjugated microporous polymer to the nano-sol, stir for 30 minutes to fully dissolve it. After adding, continue to stir and react for 8 hours. After the reaction, repeatedly filter and wash with deionized water and methanol to obtain a composite material (porphyrin-based conjugated microporous polymer modified zinc oxide).

[0128] Composite material Example 2

[0129] A composite material, the difference in its preparation method compared with Composite material Example 1 is that:

[0130] In Step 13, add 5 mg of porphyrin-based conjugated microporous polymer to the nano-sol, that is, mix 5 mg of porphyrin-based conjugated microporous polymer with 100 mg of nano-zinc oxide.

[0131] Composite material Example 3

[0132] A composite material, the difference in its preparation method compared with Composite material Example 1 is that:

[0133] In Step 13, add 20 mg of porphyrin-based conjugated microporous polymer to the nano-sol, that is, mix 20 mg of porphyrin-based conjugated microporous polymer with 100 mg of nano-zinc oxide.

[0134] Device Example 1

[0135] A QLED device, its preparation method includes:

[0136] Step 21: Place the patterned ITO substrate in acetone, cleaning solution, deionized water, and isopropanol in sequence for ultrasonic cleaning. Each ultrasonic cleaning lasts for 15 minutes. After ultrasonic cleaning is completed, place the ITO substrate in a clean oven and dry it for standby;

[0137] Step 22: After the ITO substrate is dried, treat the surface of the ITO substrate with ultraviolet-ozone for 5 minutes to further remove the organic substances attached to the surface of the ITO substrate and improve the work function of ITO.

[0138] Step 23: Deposit a hole injection layer (PEDOT:PSS) on the surface of the treated ITO substrate. The thickness of the hole injection layer is 30 nm, and place the ITO substrate on a heating table at 150 °C for 30 minutes to remove moisture. This step is completed in air.

[0139] Step 24: Place the dried ITO substrate with the hole injection layer in a nitrogen atmosphere, deposit a hole transport layer (TFB). The thickness of the hole transport layer is 30 nm, and place it on a heating table at 150 °C for 30 minutes to remove the solvent.

[0140] Step 25: After the film processed in the previous step is cooled, deposit the quantum dot light-emitting layer on the surface of the hole transport layer. The thickness of the quantum dot light-emitting layer is 40 nm. After the deposition of this step, place the film on a heating table at 80 °C for 10 minutes to remove the residual solvent.

[0141] Step 26: Disperse the composite material prepared in Composite Material Example 1 in ethanol to obtain a composite material solution with a concentration of 25 mg / mL. Spin-coat the composite material solution on the quantum dot light-emitting layer at a spin-coating speed of 3000 rpm. The spin-coated film is heat-treated at 80 °C for 30 minutes to obtain an electron transport layer with a thickness of 80 nm.

[0142] Step 27: Place the film with all functional layers deposited in an evaporation chamber and thermally evaporate a layer of 80 nm of Ag as the cathode through a mask plate, and the QLED device is fabricated.

[0143] Device Example 2

[0144] A QLED device, the difference between its fabrication method and that of Device Example 1 is only that:

[0145] In Step 26, disperse the composite material prepared in Composite Material Example 2 in ethanol to obtain a composite material solution with a concentration of 25 mg / mL.

[0146] Device Example 3

[0147] A QLED device, the difference between its fabrication method and that of Device Example 1 is only that:

[0148] In Step 26, disperse the composite material prepared in Composite Material Example 3 in ethanol to obtain a composite material solution with a concentration of 25 mg / mL.

[0149] Device Example 4

[0150] A QLED device, the difference between its preparation method and that of Device Example 1 is only that:

[0151] In Step 26, the thickness of the prepared electron transport layer is 40 nm.

[0152] Device Example 5

[0153] A QLED device, the difference between its preparation method and that of Device Example 1 is only that:

[0154] In Step 26, the thickness of the prepared electron transport layer is 120 nm.

[0155] Device Comparative Example 1

[0156] A QLED device, the difference between its preparation method and that of Device Example 1 is only that Step 26 is different. In this Device Comparative Example 1, Step 26 is as follows: Spin-coat a zinc oxide nanoparticle solution on the quantum dot light-emitting layer at a spin-coating speed of 3000 rpm, and heat-treat the spin-coated film at 80 °C for 30 minutes to obtain an electron transport layer with a thickness of 80 nm.

[0157] It can be seen that the difference between the QLED device of Device Comparative Example 1 and the QLED device of Device Example 1 is only that: the materials of the electron transport layers are different. In Device Comparative Example 1, the material of the electron transport layer is unmodified zinc oxide nanoparticles, while in Device Example 1, the material of the electron transport layer is a composite material (i.e., zinc oxide modified with porphyrin-based conjugated microporous polymer).

[0158] Performance tests were carried out on the QLED devices prepared in Device Examples 1 - 5 and the QLED device prepared in Device Comparative Example 1. Among them, T95@1000 nit / (h) was mainly tested by a lifetime test system built with a Keithley 2400 digital source meter, a CS-160 luminance meter, and a photodiode detector, and the external quantum efficiency (EQE) was measured by an EQE optical test instrument. The test results are shown in Table 1.

[0159] Table 1

[0160]

[0161] As can be seen from Table 1, the service life (T95@1000nit) of the QLED devices in Device Examples 1-5 is greater than that of the QLED device in Device Comparative Example 1, indicating that the QLED devices prepared in Device Examples 1-5 have a longer service life; the external quantum efficiency (EQE) of the QLED devices in Device Examples 1-5 is greater than that of the QLED device in Device Comparative Example 1, indicating that the QLED devices prepared in Device Examples 1-5 have a higher luminous efficiency; that is to say, compared with the QLED device in Device Comparative Example 1, the QLED devices prepared in Device Examples 1-5 have better electrical properties and stability. This is because the material used for the electron transport layer of the QLED devices in Device Examples 1-5 is a composite material (i.e., porphyrin-based conjugated microporous polymer modified zinc oxide). Compared with unmodified nano-zinc oxide, porphyrin-based conjugated microporous polymer modified zinc oxide has a higher electron transport efficiency, which can improve the electron transport efficiency of the electron transport layer, reduce the electron injection barrier between the electron transport layer and the light-emitting layer, thereby facilitating the carrier balance in the light-emitting layer, and further improving the electrical properties of the electroluminescent device. At the same time, since the porphyrin-based conjugated microporous polymer has the property of isolating water and oxygen, when the polymer is connected to the inorganic nanoparticles, the influence of external water and oxygen on the inorganic nanoparticles can be weakened or eliminated, so that the performance of the inorganic nanoparticles remains stable.

[0162] By comparing Device Example 1, Device Example 2, and Device Example 3, it can be seen that the QLED device prepared in Device Example 2 has the longest service life (T95@1000nit) and the largest external quantum efficiency (EQE), indicating that when the mass ratio of the porphyrin-based conjugated microporous polymer to nano-zinc oxide is 1:20, the QLED device has better electrical properties.

[0163] By comparing Device Example 1, Device Example 4, and Device Example 5, it can be seen that the QLED device prepared in Device Example 1 has the longest service life (T95@1000nit) and the largest external quantum efficiency (EQE), indicating that when the thickness of the electron transport layer is 80nm, the QLED device has better electrical properties.

[0164] The above has introduced in detail the composite material, its preparation method, light-emitting device, and display device provided by the embodiments of the present application. Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the present application. At the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A composite material, characterized in that, It includes inorganic nanoparticles and a polymer connected to the inorganic nanoparticles, and the polymer contains porphyrin groups.

2. The composite material according to claim 1, wherein, The polymer is a porphyrin-based conjugated microporous polymer.

3. The composite material according to claim 2, characterized in that, The porphyrin-based conjugated microporous polymer includes a repeating unit having the structure shown in formula (Ⅰ): In the porphyrin-based conjugated microporous polymer, the repeating number n of the unit shown in formula (Ⅰ) is 2 to 10.

4. The composite material according to claim 1, characterized in that, The polymer includes micropores, the pore diameter of the micropores is 0.01 nm to 2 nm, and the total volume of the plurality of micropores accounts for 15% to 40% of the volume in the polymer.

5. The composite material according to claim 1, characterized in that, The inorganic nanoparticles are selected from at least one of metal oxides, doped metal oxides, group II-VI semiconductor materials, group III-V semiconductor materials, and group I-III-VI semiconductor materials; and / or The metal oxide is selected from at least one of ZnO, BaO, TiO2, and SnO2; and / or The metal oxide in the doped metal oxide is selected from at least one of ZnO, TiO2, and SnO2, and the doping element is selected from at least one of Al, Mg, Li, In, and Ga; and / or The group II-VI semiconductor material is selected from at least one of ZnS, ZnSe, and CdS; and / or The group III-V semiconductor material is selected from at least one of InP and GaP; and / or The group I-III-VI semiconductor material is selected from at least one of CuInS and CuGaS.

6. The composite material according to claim 1, characterized in that, The mass ratio of the polymer to the inorganic nanoparticles is (1 to 5):20; and / or The composite material further includes a surfactant, the surfactant is at least distributed on the outer surface of the inorganic nanoparticles, and the molar ratio of the surfactant to the inorganic nanoparticles is 1:(2 to 8).

7. A method for preparing a composite material, characterized in that, It includes: Providing a polymer dispersion solution and an inorganic nanoparticle dispersion solution; the polymer dispersion solution includes a first solvent and a polymer dispersed in the first solvent, and the polymer contains porphyrin groups; the inorganic nanoparticle dispersion solution includes a second solvent and inorganic nanoparticles dispersed in the second solvent; Mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution to obtain a composite material dispersion solution; Performing solid-liquid separation on the composite material dispersion solution to obtain a composite material, and the composite material includes a polymer and a plurality of inorganic nanoparticles uniformly dispersed inside the polymer.

8. The method for preparing the composite material according to claim 7, characterized in that, In the composite material dispersion solution, the mass ratio of the polymer to the inorganic nanoparticles is (1 to 5):20; The mixing of the polymer dispersion solution and the inorganic nanoparticle dispersion solution includes: mixing the polymer dispersion solution and the inorganic nanoparticle dispersion solution at a temperature of 3°C to 10°C, and stirring and reacting for 5 hours to 10 hours after mixing.

9. The preparation method of the composite material according to claim 7, characterized in that, The inorganic nanoparticle dispersion solution further includes a surfactant, and the molar ratio of the surfactant to the inorganic nanoparticles is 1:(2 to 8).

10. The method for preparing the composite material according to claim 7, wherein The providing of the polymer dispersion solution includes: providing a polymer, and dissolving the polymer in a first solvent to obtain a polymer dispersion solution; and / or The provided inorganic nanoparticle dispersion solution includes: providing inorganic nanoparticles, and dissolving the inorganic nanoparticles in a second solvent to obtain an inorganic nanoparticle dispersion solution.

11. The preparation method of the composite material according to claim 10, characterized in that, The polymer is a porphyrin-based conjugated microporous polymer. The providing of the polymer includes: mixing tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-(dicyclohexylphosphino)-2',4',6'-triisopropylbiphenyl, a catalyst, and a third solvent, and reacting at a temperature of 100°C to 120°C for 40 hours to 56 hours to obtain a porphyrin-based conjugated microporous polymer; wherein, the molar ratio of tetrabromophenyl porphyrin, p-phenylenediamine, sodium tert-butoxide, 2-(dicyclohexylphosphino)-2',4',6'-triisopropylbiphenyl, and the catalyst is 1:(2 to 5):(4 to 6):(0.1 to 0.14):(0.06 to 0.1); and / or The inorganic nanoparticles are zinc oxide nanoparticles. The providing of the inorganic nanoparticles includes: mixing a precipitant solution and a zinc salt solution, and reacting at a temperature of 50°C to 70°C for 2 hours to 3 hours to obtain zinc oxide nanoparticles, wherein the molar ratio of the precipitant to the zinc salt is (1 to 2):

6.

12. A light-emitting device, characterized in that, It includes a first electrode and a second electrode disposed opposite to each other, and an electron transport layer and a light-emitting layer disposed between the first electrode and the second electrode. The material of the electron transport layer is the composite material as described in any one of claims 1-6 or the composite material prepared by the preparation method of the composite material as described in any one of claims 7-11.

13. The light-emitting device according to claim 12, wherein The light-emitting device further includes a hole transport layer and a hole injection layer; When the first electrode is an anode and the second electrode is a cathode, the light-emitting layer, the hole transport layer, and the hole injection layer are disposed between the electron transport layer and the first electrode, and the light-emitting layer, the hole transport layer, and the hole injection layer are sequentially stacked in the direction from the electron transport layer to the first electrode; When the first electrode is a cathode and the second electrode is an anode, the light-emitting layer, the hole transport layer, and the hole injection layer are disposed between the electron transport layer and the second electrode, and the light-emitting layer, the hole transport layer, and the hole injection layer are sequentially stacked in the direction from the electron transport layer to the second electrode.

14. The light-emitting device according to claim 13, wherein, The materials of the hole transport layer include at least one of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, polysfluorene and its derivatives, polythiophene and its derivatives; and / or The materials of the hole injection layer include at least one of poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid and its derivatives, copper phthalocyanine, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, poly(dioxyethylthiophene), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, transition metal oxides and transition metal chalcogenides; and / or The first electrode and the second electrode are independently selected from a metal oxide electrode, a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal elemental electrode or an alloy electrode respectively. The material of the metal oxide electrode includes molybdenum oxide. The material of the doped metal oxide electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide. The composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS or ZnS / Al / ZnS. The material of the metal elemental electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba; and / or The materials of the light-emitting layer include organic light-emitting materials or quantum dot light-emitting materials. The organic light-emitting materials include one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4''-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium], diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, 1,4,7,10-tetra-tert-butyl naphthacene, rubrene derivatives, thermally activated delayed fluorescence materials, exciplex light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;The quantum dot light-emitting material includes at least one of single-structure quantum dots and core-shell structure quantum dots. The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots each include at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.; 15. The light-emitting device according to claim 13, characterized in that, The thickness of the first electrode is 60 nm - 100 nm, the thickness of the hole injection layer is 10 nm - 50 nm, the thickness of the hole transport layer is 10 nm - 50 nm, the thickness of the light-emitting layer is 20 nm - 60 nm, the thickness of the electron transport layer is 40 nm - 120 nm, and the thickness of the second electrode is 60 nm - 100 nm.

16. A display device, characterized in that, A light-emitting device comprising the light-emitting device according to any one of claims 12 - 15.

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