Light-emitting device and preparation method thereof

Abstract

The invention belongs to the technical field of display, and relates to a light-emitting device which comprises a first electrode, a light-emitting layer and a second electrode, and materials of the light-emitting layer comprise a light-emitting material and an anti-oxidation material; the antioxidant material is selected from one or more of a chain blocking type antioxidant and a metal ion deactivator; the invention also relates to a preparation method of the light-emitting device. According to the technical scheme provided by the invention, the interaction between oxygen and the triplet state of the luminescent material can be inhibited or reduced, so that the exciton annihilation rate is reduced, the luminous efficiency of the luminescent device is improved, and the service life of the luminescent device is prolonged.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light-emitting device and its fabrication method. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have broad application prospects in the display and lighting fields due to their thinness, flexibility, fast response speed and self-emission. In OLEDs, energy is released through exciton radiative transitions to emit light. However, the non-radiative annihilation of excitons affects the efficiency and lifespan of OLEDs.

[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0004] In view of the above, this application provides a light-emitting device, which adopts the technical solution described below:

[0005] It includes a first electrode, a light-emitting layer, and a second electrode stacked sequentially.

[0006] The material of the light-emitting layer includes a light-emitting material and an antioxidant material;

[0007] The antioxidant material is selected from one or more of chain-blocking antioxidants and metal ion deactivators.

[0008] Furthermore, the chain-blocking antioxidant is selected from organic amine compounds, phenolic compounds, vitamin C, vitamin E, carotenoids; and / or,

[0009] The metal ion deactivator is selected from organic acids or organic acid salts.

[0010] Furthermore, the organic amine compounds include N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and diethanolamine;

[0011] And / or, the phenolic compounds include catechol, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, catechins, and anthocyanins;

[0012] And / or, the carotenoids include β-carotene, lutein, and zeaxanthin;

[0013] And / or, the metal ion deactivator includes at least one of citric acid, ethylenediaminetetraacetic acid, di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate, citrate, ethylenediaminetetraacetic acid salt, and di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate; optionally, the citrate includes sodium citrate and potassium citrate; the ethylenediaminetetraacetic acid salt includes sodium ethylenediaminetetraacetic acid, sodium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate, and potassium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate.

[0014] Furthermore, the antioxidant material accounts for 0.1%-5% of the mass of the luminescent layer.

[0015] Furthermore, the antioxidant material is selected from the chain-blocking antioxidant, and the luminescent material is an organic luminescent material. Optionally, the organic luminescent material is selected from at least one of PTM, TTM, TTM-1CZ, PyBTM, PTM-3NCZ, and PS-CzTTM.

[0016] Furthermore, the antioxidant material is selected from the metal ion deactivator, and the luminescent material is a metal organic light-emitting material. Optionally, the metal organic light-emitting material is selected from at least one of Ir(MDQ)2(acac), Ir(ppy)2(acac), FIr6, Phqlr, and Ir(DPF)3.

[0017] Furthermore, the luminescent material further includes a host material, which is selected from blue light host materials. Optionally, the blue light host material is selected from at least one of PVK, mCP, CBP, CDBP, DCB, DCz, CBPCH, UGH3, BSB, SimCP, Czsi, TBCPF, PTC, BTPAF1, MPO12, POAPF, 26DCzPPy, and P36EHF; and / or,

[0018] The main material accounts for 90-99% of the mass of the light-emitting layer; and / or,

[0019] The metal-organic luminescent material accounts for 0.05-5% of the mass of the luminescent layer.

[0020] Furthermore, the thickness of the light-emitting layer is 20-40 nm;

[0021] And / or, the light-emitting device further includes a hole functional layer located between the first electrode and the light-emitting layer; and / or, an electronic functional layer located between the second electrode and the light-emitting layer.

[0022] Furthermore, the first electrode and the second electrode are each independently selected from one or more of the following: metal electrode, silicon-carbon electrode, doped or undoped metal oxide electrode, and composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the silicon-carbon electrode is selected from at least one of silicon, graphite, carbon nanotubes, graphene, and carbon fiber; and the material of the doped or undoped metal oxide electrode is selected from ITO, FTO, ATO, AZO, and GZO. The composite electrode material is selected from at least one of AZO, IZO, MZO, and AMO; the material of the composite electrode is selected from at least one of 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, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or,

[0023] The hole functional layer includes a hole transport layer and / or a hole injection layer. When the hole functional layer includes a hole injection layer and a hole transport layer, the hole injection layer is disposed adjacent to the first electrode, and the hole transport layer is disposed adjacent to the light-emitting layer. The material of the hole injection layer includes HATCN, PEDOT:PSS, BTDA-TCNQ, TDA-TCNNQ, TDA-TCNAQ, MeO-TAD, m-MTDATA, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4',4"-triphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, etc. (N-3-methylphenyl-N-phenylamino)triphenylamine, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], mixtures doped with 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone doped with N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4” diamine, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate The hole transport layer comprises one or more of the following: acid, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, transition metal oxides, and transition metal chalcogenides. The transition metal oxides are selected from one or more of NiO, MoO2, MoO3, WO3, and CuO. The transition metal chalcogenides are selected from one or more of MoS2, MoSe2, WS3, WSe3, and CuS. The material of the hole transport layer includes polymer hole transport materials and small molecule hole transport materials. One or more of the hole transport materials; the polymeric hole transport material is selected from one or more of poly(N-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl)amine] and poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butylphenyl)phenyl)-diphenylamine)]; the small molecule hole transport material is selected from one or more of 4,4',4”-tris(carbazole-9-yl)triphenylamine, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] and 4,4'-di(9-carbazole)biphenyl; and / or

[0024] The electronic functional layer includes an electron transport layer and / or an electron injection layer. When the electronic functional layer includes an electron injection layer and an electron transport layer, the electron injection layer is disposed adjacent to the second electrode, and the electron transport layer is disposed adjacent to the light-emitting layer. The material of the electron transport layer is selected from tris(8-hydroxyquinoline)aluminum, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole, bis(10-hydroxybenzo[h]quinoline)beryllium, 3- (biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2,7-bis(diphenyloxyphosphino)-9,9'-spirodifluorene, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,6-bis(3,5-di(3-pyridinylphenyl)-2-methylpyrimidine, and 4,7-diphenyl-1,10-phenanthroline; the material of the electron injection layer is selected from at least one of Yb, yttrium fluoride, Li, LiF, NaF, CeF, CsCO3, Cs, KBH4, or KH.

[0025] This application also provides a method for fabricating a light-emitting device, which adopts the following technical solution:

[0026] A method for fabricating a light-emitting device includes the following steps:

[0027] Provide substrate;

[0028] A first electrode is formed on the substrate;

[0029] A hole-functional layer is formed on the first electrode;

[0030] A light-emitting layer doped with antioxidant material is formed on the hole functional layer;

[0031] An electronic functional layer is formed on the light-emitting layer;

[0032] A second electrode is formed on the electronic functional layer;

[0033] The step of forming a light-emitting layer doped with an antioxidant material on the hole functional layer includes the following steps: incorporating the antioxidant material into the light-emitting material to form a doped ink; and depositing the ink on the hole functional layer using a solution method to form the light-emitting layer.

[0034] The antioxidant material is selected from at least one or more of chain-blocking antioxidants and metal ion deactivators.

[0035] Compared with the prior art, this application has the following advantages: by doping the light-emitting layer with antioxidant materials, this application suppresses or reduces the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the luminous efficiency of the light-emitting device and extending its service life. Attached Figure Description

[0036] To more clearly illustrate the solution of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of the light-emitting device according to an embodiment of this application;

[0038] Figure 2 It is a line graph of external quantum efficiency and current density;

[0039] Figure 3 This is a surface morphology diagram of the light-emitting layer thin film.

[0040] Reference numerals: 100, first electrode; 200, light-emitting layer; 300, second electrode; 400, hole functional layer; 500, electron functional layer. Detailed Implementation

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0042] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0044] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0045] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0046] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0047] 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 merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0048] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0049] Organic light-emitting diodes (OLEDs) have broad application prospects in the display and lighting fields due to their thinness, flexibility, fast response speed, and self-emissive properties. The working principle of OLEDs is based on the electroluminescence effect of organic materials, where electrons and holes recombine in the light-emitting layer to generate excitons. These excitons release energy through radiative transitions, thereby emitting light. However, the efficiency and lifetime of OLEDs are limited by several factors, one of which is the non-radiative annihilation of excitons, particularly oxygen-induced triplet-triplet annihilation.

[0050] In the solution processing of OLEDs, the ink of the light-emitting layer typically contains organic light-emitting materials and solvents. To improve the efficiency and lifespan of OLEDs, researchers have explored various methods to suppress exciton annihilation. Currently, among known technologies, the use of antioxidants is an effective strategy. Antioxidants can inhibit or slow down oxidation reactions.

[0051] However, the antioxidants used in existing technologies have some drawbacks. First, some antioxidants may be incompatible with the organic materials in OLEDs, leading to reduced luminous efficiency or unstable device performance. Second, the addition of antioxidants may increase manufacturing costs, especially when high purity and specific structures of antioxidants are required. Furthermore, existing antioxidants may not be able to effectively penetrate the emissive layer or may be gradually depleted during OLED operation, thus limiting their long-term protective effect.

[0052] As attached Figure 1 To be continued Figure 2 As shown, based on the above-mentioned technical problems, this application provides a light-emitting device, including a first electrode 100, a light-emitting layer 200, and a second electrode 300 stacked sequentially.

[0053] The material of the light-emitting layer 200 includes a light-emitting material and an antioxidant material;

[0054] The antioxidant material is selected from one or more of chain-blocking antioxidants and metal ion deactivators.

[0055] This application incorporates antioxidant materials into the light-emitting layer 200. These antioxidant materials can inhibit or slow down oxidation reactions by capturing free radicals and complexing metal ions, thereby reducing the interaction between oxygen and the triplet state of the light-emitting material and lowering the exciton annihilation rate. Furthermore, the mixed use of antioxidant and light-emitting materials allows the antioxidant materials to effectively penetrate the light-emitting layer 200, exhibiting good compatibility and stability during the use of the light-emitting device, providing continuous protection and effectively suppressing exciton annihilation in the light-emitting layer 200. This, in turn, improves the luminous efficiency of the light-emitting device and extends its lifespan.

[0056] In some embodiments, the chain-blocking antioxidant is selected from organic amine compounds, phenolic compounds, vitamin C, vitamin E, and carotenoids; and / or,

[0057] The metal ion deactivator is selected from organic acids or organic acid salts.

[0058] Organic amines can prevent oxidation chain reactions by capturing and neutralizing free radicals. Phenolic compounds prevent oxidation chain reactions by reacting with various free radicals; their antioxidant mechanisms involve hydrogen atom transfer, single electron transfer, sequential proton loss electron transfer, and transition metal chelation. Vitamin C (ascorbic acid) is a water-soluble antioxidant that can donate electrons to free radicals, thereby stabilizing and scavenging them. Vitamin E (tocopherol) is a fat-soluble antioxidant that can capture free radicals and prevent the oxidation of luminescent materials. The sixth hydroxyl group on the oxanane ring of vitamin E can provide a hydrogen atom, which combines with free radicals to form stable compounds, thereby interrupting the free radical chain reaction. Vitamin E can also be oxidized by superoxide anion radicals and hydroxyl radicals, protecting luminescent materials from free radical attack. Carotenoids function by physically quenching singlet oxygen, removing excess energy from singlet oxygen and converting it back into normal oxygen molecules. Organic acids and organic acid salts can form stable chelates with metal ions through the coordinating atoms in their groups, preventing the metal ions from being oxidized and thus stabilizing the metal organic light-emitting materials.

[0059] In some embodiments, the organic amine compounds include N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (AO445), and diethanolamine;

[0060] And / or, the phenolic compounds include catechol, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, catechins, and anthocyanins;

[0061] And / or, the carotenoids include β-carotene, lutein, and zeaxanthin;

[0062] And / or, the metal ion deactivator includes at least one of citric acid, ethylenediaminetetraacetic acid, di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate, citrate, ethylenediaminetetraacetic acid salt, and di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate; optionally, the citrate includes sodium citrate and potassium citrate; the ethylenediaminetetraacetic acid salt includes sodium ethylenediaminetetraacetic acid. 、 Sodium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate and potassium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate.

[0063] Chain-blocking antioxidants, also known as free radical scavengers or primary antioxidants, work by capturing and neutralizing free radicals, preventing oxidation chain reactions. They stabilize free radicals and terminate chain reactions by donating hydrogen atoms or electrons to them, thus inhibiting or slowing down oxidation reactions, reducing the interaction between oxygen and the triplet state of luminescent materials, thereby reducing exciton annihilation rate, improving the luminous efficiency of light-emitting devices, and extending their lifespan.

[0064] The role of metal ion deactivators is to complex or chelate metal ions. By forming stable complexes with metal ions, metal ion deactivators can reduce the catalytic activity of metal ions, thereby protecting the material from oxidation, reducing the interaction between oxygen and the triplet state of the luminescent material, thereby reducing the exciton annihilation rate, improving the luminous efficiency of the light-emitting device and extending its service life.

[0065] In some embodiments, the antioxidant material accounts for 0.1%-5% of the mass of the light-emitting layer 200. The method of adding specific antioxidants and controlling their concentration suppresses or reduces the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the luminous efficiency and stability of the light-emitting device, slowing down the degradation rate of the light-emitting material, extending the lifespan of the light-emitting device, enhancing the overall performance of the light-emitting device, improving the color performance of the light-emitting device, providing richer and more stable image quality, and ensuring that the improved light-emitting device can operate stably under a wider range of environmental conditions. Simultaneously, by rationally selecting the type and doping ratio of antioxidants to reduce manufacturing costs, a balance is achieved between performance improvement and cost control.

[0066] It is understood that the mass percentage of the antioxidant material in the luminescent layer 200 can be any value or a range formed by any two values ​​of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, and 5%.

[0067] Furthermore, the antioxidant material in the luminescent layer 200 comprises one of the following by mass: 0.5%, 1%, or 3%. By adding specific antioxidants and controlling their concentration, the interaction between oxygen and the triplet state of the luminescent material is suppressed or reduced, thereby lowering the exciton annihilation rate. Additionally, by rationally selecting the type and doping ratio of antioxidants, manufacturing costs are reduced, achieving a balance between performance improvement and cost control.

[0068] In some embodiments, the antioxidant material is selected from the chain-blocking antioxidant, and the luminescent material is an organic luminescent material. Optionally, the organic luminescent material is selected from at least one of PTM, TTM, TTM-1CZ, PyBTM, PTM-3NCZ, and PS-CzTTM.

[0069] In some embodiments, the antioxidant material is selected from the metal ion deactivator, and the luminescent material is a metal-organic luminescent material. Optionally, the metal-organic luminescent material is selected from at least one of Ir(MDQ)2(acac), Ir(ppy)2(acac), FIr6, Phqlr, and Ir(DPF)3. TTA materials, such as TTM-1CZ, PyBTM, and PS-CzTTM, involve the triplet-triplet annihilation (TTA) mechanism, which involves the annihilation of triplet excitons to generate singlet excitons, thereby emitting light. Antioxidant materials reduce exciton loss by preventing oxygen from reacting with triplet excitons, thereby improving the luminous efficiency and stability of light-emitting devices, extending device lifetime, and reducing device performance degradation caused by oxygen.

[0070] Thermal exciton materials, such as TTM, PTM, PTM-3NCZ, TTM-PPTA, TTM-2Cz, αHTTM-1Cz, TTM-1CzBz, TTM-1CztB, TTM-3NCz, and TTM-3PCz, generate excitons through a thermal activation process. Antioxidant materials help protect excited-state molecules from oxidation, thereby maintaining their luminescent properties, enhancing the photostability of the material, reducing non-radiative recombination of thermal excitons, and improving luminescent efficiency and color stability.

[0071] TADF materials, such as Ir(MDQ)₂(acac), Ir(ppy)₂(acac), FIr₆, and Phqlr, are thermally activated delayed fluorescence (TADF) materials that emit light by returning from a triplet state to a singlet excited state via reverse system crossing (RISC). Antioxidant materials can reduce the interaction between oxygen and excited-state molecules, improving the luminescence efficiency of TADF materials, reducing oxygen-induced exciton quenching, extending the lifespan of light-emitting devices, and maintaining the device's emission color and brightness.

[0072] In some embodiments, the luminescent material further includes a host material selected from blue light host materials. Optionally, the blue light host material is selected from at least one of PVK, mCP, CBP, CDBP, DCB, DCz, CBPCH, UGH3, BSB, SimCP, Czsi, TBCPF, PTC, BTPAF1, MPO12, POAPF, 26DCzPPy, and P36EHF; and / or,

[0073] The main material accounts for 90-99% of the mass of the light-emitting layer 200; and / or,

[0074] The metal-organic luminescent material accounts for 0.05-5% of the mass of the luminescent layer 200.

[0075] The host material is usually used in combination with the metal-organic light-emitting material in light-emitting devices. That is, the metal-organic light-emitting material is the guest material. The host material can help improve the photoluminescence efficiency of the light-emitting layer, while reducing exciton quenching, such as triplet-triplet exciton quenching, promoting charge injection and transport, and improving light-emitting performance. Selecting and setting an appropriate mass ratio of the host material and the metal-organic light-emitting material can optimize luminescence efficiency and color stability, control brightness, reduce material degradation, and extend lifespan.

[0076] It is understood that the mass percentage of the main material in the light-emitting layer 200 can be any value or a range formed by any two of the following: 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, and 99%. The mass percentage of the metal-organic luminescent material in the luminescent layer 200 can be any value or a range formed by any two values ​​from 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, to 5%.

[0077] In some embodiments, the luminescent material accounts for 95%-99.9% of the mass of the luminescent layer 200. The material of the luminescent layer 200 includes luminescent material and antioxidant material, and the sum of their proportions is 1. By rationally selecting the type and doping ratio of antioxidants, the manufacturing cost is reduced, achieving a balance between performance improvement and cost control.

[0078] It is understood that the mass percentage of the luminescent material in the luminescent layer 200 can be any value or a range formed by any two of the following: 95%, 96%, 97%, 98%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, and 99.9%.

[0079] In some embodiments, the thickness of the light-emitting layer is 20-40 nm;

[0080] And / or, the light-emitting device further includes a hole functional layer 400 located between the first electrode 100 and the light-emitting layer 200; and / or, an electron functional layer 500 located between the second electrode 300 and the light-emitting layer 200. Setting an appropriate thickness for the light-emitting layer can optimize luminous efficiency, control brightness, reduce material degradation, and extend lifespan. The hole functional layer 400 is used to transport holes from the anode to the light-emitting layer 200, and the electron functional layer 500 is used to transport electrons from the cathode to the light-emitting layer 200.

[0081] It is understood that the thickness of the light-emitting layer is within the range of any one or any two values ​​of 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, and 40nm.

[0082] In some embodiments, the first electrode 100 and the second electrode 300 are each independently selected from one or more of a metal electrode, a silicon-carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the silicon-carbon electrode is selected from at least one of silicon, graphite, carbon nanotubes, graphene, and carbon fibers; and the material of the doped or undoped metal oxide electrode is selected from ITO, FTO, ATO, and AZ. O, GZO, IZO, MZO, and AMO are selected as at least one of the following: 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, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or,

[0083] The hole functional layer 400 includes a hole transport layer and / or a hole injection layer. When the hole functional layer 400 includes a hole injection layer and a hole transport layer, the hole injection layer is disposed adjacent to the first electrode 100, and the hole transport layer is disposed adjacent to the light-emitting layer 200. The material of the hole injection layer includes HATCN, PEDOT:PSS, BTDA-TCNQ, TDA-TCNNQ, TDA-TCNAQ, MeO-TAD, m-MTDATA, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4',4"-triphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, etc. (N-3-methylphenyl-N-phenylamino)triphenylamine, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], mixtures doped with 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone doped with N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4” diamine, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,3,5,6-tetrafluoro... -7,7',8,8'-Tetracyanodimethyl-p-benzoquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, transition metal oxides, and transition metal chalcogenides are selected from one or more of NiO, MoO2, MoO3, WO3, and CuO, and transition metal chalcogenides are selected from one or more of MoS2, MoSe2, WS3, WSe3, and CuS; the hole transport layer material includes one or more of polymer hole transport materials and small molecule hole transport materials; the polymer hole transport material is selected from... Poly(N-vinylcarbazole) (PVK), poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD), and poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butylphenyl)-diphenylamine)] (TFB) are selected from one or more of these materials; the small molecule hole transport material is selected from one or more of 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), and 4,4'-bis(9-carbazole)biphenyl (CBP); and / or,

[0084] The electronic functional layer 500 includes an electron transport layer and / or an electron injection layer. When the electronic functional layer 500 includes an electron injection layer and an electron transport layer, the electron injection layer is disposed adjacent to the second electrode 300, and the electron transport layer is disposed adjacent to the light-emitting layer 200. The material of the electron transport layer is selected from tris(8-hydroxyquinoline)aluminum (Alq3), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1), 1,3,5-tris(3-pyridyl-3-phenyl)benzene (TmPyPB), 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole (PBD), and bis(10-hydroxybenzo[h]quinoline)beryllium (BeBq). 2) One or more of 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), 2,7-bis(diphenyloxyphosphino)-9,9'-spirodifluorene (SPPO13), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI), 4,6-bis(3,5-di(3-pyridinylphenyl)-2-methylpyrimidine (B3PYMPM), and 4,7-diphenyl-1,10-phenanthroline (BPhen); the material of the electron injection layer is selected from at least one of Yb, yttrium fluoride, Li, LiF, NaF, CeF, CsCO3, Cs, KBH4, or KH.

[0085] Choosing suitable materials enables the first and second electrodes to have high conductivity, good chemical stability, and good contact with other layers of the device; enables the hole injection layer to reduce the energy barrier for holes to be injected from the anode to the light-emitting layer; enables the hole transport layer to optimize the thickness matching of the functional layers of the device; enables the electron injection layer to increase the ability of electrons to be injected from the cathode to the light-emitting layer; and enables the electron transport layer to improve electron transport performance and achieve effective recombination of electrons and holes.

[0086] As attached Figure 1 As shown, based on the above-described light-emitting device, this application embodiment also provides a display panel including the light-emitting device.

[0087] This application incorporates antioxidant materials into the light-emitting layer 200. These antioxidant materials can inhibit or slow down oxidation reactions by capturing free radicals and complexing metal ions, thereby reducing the interaction between oxygen and the triplet state of the light-emitting material and lowering the exciton annihilation rate. Furthermore, the mixed use of antioxidant and light-emitting materials allows the antioxidant materials to effectively penetrate the light-emitting layer 200, exhibiting good compatibility and stability during the use of the light-emitting device, providing continuous protection and effectively suppressing exciton annihilation in the light-emitting layer 200. This, in turn, improves the luminous efficiency of the light-emitting device and extends its lifespan.

[0088] As attached Figure 1 As shown, based on the above-described light-emitting device, this application embodiment also provides a method for fabricating a light-emitting device, including the following steps:

[0089] S100 provides a substrate;

[0090] S200, a first electrode 100 is formed on the substrate;

[0091] S300, a hole functional layer 400 is formed on the first electrode 100;

[0092] S400, a light-emitting layer 200 doped with an antioxidant material is formed on the hole functional layer 400;

[0093] S500, an electronic functional layer 500 is formed on the light-emitting layer 200;

[0094] S600, a second electrode 300 is formed on the electronic functional layer 500;

[0095] The step of forming a light-emitting layer 200 doped with an antioxidant material on the hole functional layer 400 includes the following steps:

[0096] The antioxidant material is incorporated into the luminescent material to form a doped ink;

[0097] The ink is deposited onto the hole functional layer 400 using a solution method to form the light-emitting layer 200;

[0098] The antioxidant material is selected from at least one or more of chain-blocking antioxidants and metal ion deactivators.

[0099] This application provides a method for preparing a light-emitting device that is easily integrated into existing manufacturing processes. Specifically, it involves doping the light-emitting layer 200 with an antioxidant material. This addition method is easy to implement, has good compatibility with existing light-emitting device manufacturing processes, and simplifies the production process. Furthermore, by carefully selecting an antioxidant material compatible with the light-emitting material and using a reasonable doping ratio, a balance is achieved between performance improvement and cost control. The antioxidant material can inhibit or slow down oxidation reactions through mechanisms such as capturing free radicals and complexing metal ions, reducing the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate. Moreover, the antioxidant material and the light-emitting material are used in combination, allowing the antioxidant material to effectively penetrate the light-emitting layer 200, exhibiting good compatibility and remaining stable during the use of the light-emitting device, providing continuous protection, thereby improving the luminous efficiency of the light-emitting device and extending its service life.

[0100] Furthermore, when preparing the ink for the light-emitting layer 200, a solvent is added. The solvent is selected from at least one of methyl benzoate, toluene, xylene, chlorobenzene, chloroform, dichloromethane, chloroform, cyclohexanone, cyclohexylbenzene, acetone, and acetonitrile, and the concentration of the solvent is 20 mg / ml.

[0101] The following specific embodiments will be used to illustrate the thin film of this application. These embodiments are only some of the embodiments of this application and are not intended to limit the application.

[0102] Example 1

[0103] Step 1: Provide a substrate;

[0104] Step 2: An anode is formed on the substrate, and a transparent conductive film ITO with a thickness of 50 nm is used as the anode;

[0105] Step 3: PEDOT:PSS is deposited on ITO using a solution method as a hole injection layer with a thickness of 30 nm.

[0106] Step 4: Deposit PVK as a hole transport layer on the hole injection layer using a solution method, with a thickness of 25 nm.

[0107] Step 5: Deposit an OLED light-emitting layer with a thickness of 35nm on the hole transport layer using a solution method;

[0108] The material of the light-emitting layer includes a light-emitting material and an antioxidant material. The light-emitting material is PTM, and the antioxidant material is N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant. The doping ratio of the light-emitting material is 99.5%, and the doping ratio of the antioxidant material is 0.5%. The solvent is chloroform, the total ink concentration of the light-emitting layer material is 6 mg / ml, the spin coating speed and spin coating time are 1000 rpm and 30 s, the baking temperature and baking time are 60℃ and 15 mins, and the thickness is 35 nm.

[0109] Step 6: Deposit TmPyPB as an electron transport layer on the light-emitting layer using a vapor deposition method, with a thickness of 30 nm;

[0110] Step 7: Deposit LiF as an electron injection layer on the electron transport layer using a vapor deposition method, with a thickness of 1 nm;

[0111] Step 8: Deposit Al as a cathode on the electron transport layer using a vapor deposition method, with a thickness of 100 nm.

[0112] Example 2: This example is basically the same as Example 1, except that the doping ratio of luminescent material of 99.5% and the doping ratio of antioxidant material of 0.5% in step five is replaced with the doping ratio of luminescent material of 99% and the doping ratio of antioxidant material of 1%.

[0113] Example 3: This example is basically the same as Example 1, except that the doping ratio of luminescent material of 99.5% and the doping ratio of antioxidant material of 0.5% in step five is replaced with the doping ratio of luminescent material of 97% and the doping ratio of antioxidant material of 3%.

[0114] Example 4

[0115] Step 1: Provide a substrate;

[0116] Step 2: An anode is formed on the substrate, and a transparent conductive film ITO with a thickness of 50 nm is used as the anode;

[0117] Step 3: PEDOT:PSS is deposited on ITO using a solution method as a hole injection layer with a thickness of 30 nm.

[0118] Step 4: Deposit PVK as a hole transport layer on the hole injection layer using a solution method, with a thickness of 25 nm.

[0119] Step 5: Deposit an OLED light-emitting layer with a thickness of 35nm on the hole transport layer using a solution method;

[0120] The light-emitting layer comprises a light-emitting material and an antioxidant material. The light-emitting material is PTM, and the antioxidant material is 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (AO445) in the chain-blocking antioxidant. The doping ratio of the light-emitting material is 99.5%, and the doping ratio of the antioxidant material is 0.5%. The solvent is chloroform, the total ink concentration of the light-emitting layer material is 6 mg / ml, the spin coating speed and spin coating time are 1000 rpm and 30 s, the baking temperature and baking time are 60℃ and 15 mins, and the thickness is 35 nm.

[0121] Step 6: Deposit TmPyPB as an electron transport layer on the light-emitting layer using a vapor deposition method, with a thickness of 30 nm;

[0122] Step 7: Deposit LiF as an electron injection layer on the electron transport layer using a vapor deposition method, with a thickness of 1 nm;

[0123] Step 8: Deposit Al as a cathode on the electron transport layer using a vapor deposition method, with a thickness of 100 nm.

[0124] Example 5: This example is basically the same as Example 4, except that the doping ratio of luminescent material of 99.5% and the doping ratio of antioxidant material of 0.5% in step five is replaced with the doping ratio of luminescent material of 99% and the doping ratio of antioxidant material of 1%.

[0125] Example 6: This example is basically the same as Example 4, except that the doping ratio of luminescent material of 99.5% and the doping ratio of antioxidant material of 0.5% in step 5 is replaced with the doping ratio of luminescent material of 97% and the doping ratio of antioxidant material of 3%.

[0126] Example 7: This example is basically the same as Example 2, except that the luminescent material in step five is replaced with the luminescent material TTM.

[0127] Example 8: This example is basically the same as Example 2, except that the luminescent material in step five is replaced with the luminescent material TTM-1CZ.

[0128] Example 9: This example is basically the same as Example 2, except that the luminescent material in step five is replaced with PyBTM.

[0129] Example 10: This example is basically the same as Example 2, except that the luminescent material in step five is replaced with PTM-3NCZ.

[0130] Example 11: This example is basically the same as Example 2, except that the luminescent material in step five is replaced by PTM with PS-CzTTM.

[0131] Comparative Example 1

[0132] Step 1: Provide a substrate;

[0133] Step 2: An anode is formed on the substrate, and a transparent conductive film ITO with a thickness of 50 nm is used as the anode;

[0134] Step 3: PEDOT:PSS is deposited on ITO using a solution method as a hole injection layer with a thickness of 30 nm.

[0135] Step 4: Deposit PVK as a hole transport layer on the hole injection layer using a solution method, with a thickness of 25 nm.

[0136] Step 5: Deposit an OLED light-emitting layer on the hole transport layer using a solution method. The light-emitting layer material is PTM, and the thickness is 35nm.

[0137] Step 6: Deposit TmPyPB as an electron transport layer on the light-emitting layer using a vapor deposition method, with a thickness of 30 nm;

[0138] Step 7: Deposit Li as an electron injection layer on the electron transport layer using a vapor deposition method, with a thickness of 1 nm;

[0139] Step 8: Deposit Al as a cathode on the electron transport layer using a vapor deposition method, with a thickness of 100 nm.

[0140] Comparative Example 2: This comparative example is basically the same as Comparative Example 1, except that the luminescent material in step five is replaced by TTM instead of PTM.

[0141] Comparative Example 3: This comparative example is basically the same as Comparative Example 1, except that the luminescent material in step five is replaced by TTM-1CZ instead of PTM.

[0142] Comparative Example 4: This comparative example is basically the same as Comparative Example 1, except that the luminescent material in step five is replaced with PyBTM.

[0143] Comparative Example 5: This comparative example is basically the same as Comparative Example 1, except that the luminescent material in step five is replaced with PTM-3NCZ.

[0144] Comparative Example 6: This comparative example is basically the same as Comparative Example 1, except that the luminescent material in step five is replaced with PTM and the luminescent material is PS-CzTTM.

[0145] The antioxidant materials used in Examples 1-3 and 7-11 were selected from N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine, one of the chain-blocking antioxidants. The light-emitting devices prepared in Examples 1-3, 7-11, and Comparative Examples 1-6 were subjected to optical performance tests. The driving voltage was measured using a voltage source and an ammeter; the external quantum efficiency was measured using the integrating sphere method; and the T95 lifetime (h) of the light-emitting device when its brightness decayed to 95% was measured. The types, doping ratios, and test results of the light-emitting materials and antioxidant materials in Examples 1-3, 7-11, and Comparative Examples 1-6 are shown in Table 1 below.

[0146] Table 1: N-Phenylon-N'-(1,3-Dimethyl)butyl-p-phenylenediamine

[0147]

[0148] Where V@1cd / m2 represents the driving voltage corresponding to a brightness of 1cd / m2; EQE maxT95(h)@1000cd / m2 represents the maximum EQE when the IVL curve is measured; T95(h)@1000cd / m2 represents the time it takes for the device to continuously light up at an initial brightness of 1000cd / m2, until the brightness decays to 95% of the initial brightness (950cd / m2 in this case).

[0149] As shown in Table 1:

[0150] As shown in Examples 1-3 and Comparative Example 1, the driving voltage of the light-emitting devices in Examples 1-3 is lower than that in Comparative Example 1. The lower operating voltage helps reduce the device aging rate. The external quantum efficiency and lifetime of the light-emitting devices in Examples 1-3 are significantly improved compared to Comparative Example 1. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifetime of the light-emitting device.

[0151] As shown in Examples 7-11 and Comparative Examples 2-6, compared to Comparative Examples 2, 8, 9, 10, and 6 respectively, the driving voltage of the light-emitting devices in Examples 7 is lower than that in Comparative Examples 3, 9, 10, and 11 respectively. The lower operating voltage helps reduce the device aging rate. Furthermore, the external quantum efficiency and lifespan of the light-emitting devices in Examples 7 and 11 are significantly improved compared to the comparative examples. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the quantum dot excitation efficiency of the light-emitting device, and extending the lifespan of the light-emitting device.

[0152] As shown in Examples 1-3, 7-11, and Comparative Examples 1-6, the reduction in driving voltage and the improvement in external quantum efficiency and lifespan of the light-emitting device are influenced by both the doping ratio of the antioxidant material in the light-emitting layer 200 and the specific type of light-emitting material selected. If the specific type of light-emitting material is not matched with the doping ratio of the antioxidant material, the reduction in driving voltage and the improvement in external quantum efficiency and lifespan are not optimal. Therefore, the specific type of light-emitting material should be matched with the doping ratio of the antioxidant material. For example, when the light-emitting material is PTM, the doping ratio of the antioxidant material in the light-emitting layer 200 is 1%; when the light-emitting material is TTM-1CZ, the doping ratio of the antioxidant material in the light-emitting layer 200 is 1%. By rationally selecting the type of light-emitting material and the doping ratio of the antioxidant, manufacturing costs are reduced, achieving a balance between performance improvement and cost control, and obtaining the best results.

[0153] The antioxidants in Examples 4-6 are selected from 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (AO445) among the chain-blocking antioxidants.

[0154] The light-emitting devices prepared in Examples 4-6 were subjected to optical performance tests. The driving voltage was measured using a voltage source and an ammeter; the external quantum efficiency was measured using the integrating sphere method; and the T95 lifetime (h) when the brightness of the light-emitting device decayed to 95% was measured. The types of light-emitting materials and antioxidant materials, the doping ratios, and the test results of Examples 4-6 and Comparative Example 1 are shown in Table 2 below.

[0155] Table 2: 4,4'-Bis(α,α-dimethylbenzyl)diphenylamine (AO445)

[0156]

[0157] As shown in Table 2, based on Examples 4-6 and Comparative Example 1, the driving voltage of the light-emitting devices in Examples 4-6 is lower than that in Comparative Example 1. The lower operating voltage helps reduce the device aging rate. The external quantum efficiency and lifespan of the light-emitting devices in Examples 4-6 are significantly improved compared to Comparative Example 1. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifespan of the light-emitting device.

[0158] The antioxidants used in the following examples are selected from phenolic compounds, vitamin C, vitamin E, and carotenoids in the chain-blocking antioxidants.

[0159] Example 12: This example is basically the same as Example 2, except that N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant in step five is replaced with catechol in the phenolic compound.

[0160] Example 13: This example is basically the same as Example 2, except that N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant in step five is replaced with vitamin C.

[0161] Example 14: This example is basically the same as Example 2, except that N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant in step five is replaced with vitamin E.

[0162] Example 15: This example is basically the same as Example 2, except that N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant in step five is replaced with β-carotene in the carotenoids.

[0163] The light-emitting devices prepared in Examples 12-15 were subjected to optical performance tests. The types of light-emitting materials and antioxidant materials, doping ratios, and test results of Examples 12-15 and Comparative Example 1 are shown in the table below.

[0164] Table 3

[0165]

[0166] As shown in Table 3, based on Examples 12-15 and Comparative Example 1, the driving voltage of the light-emitting devices in Examples 12-15 is lower than that in Comparative Example 1. The lower operating voltage helps reduce the device aging rate. The external quantum efficiency and lifespan of the light-emitting devices in Examples 12-15 are significantly improved compared to Comparative Example 1. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifespan of the light-emitting device.

[0167] The antioxidants used in the following examples are selected from sodium citrate, one of the metal ion deactivators.

[0168] Example 16: This example is basically the same as Example 2, except that N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine in the chain-blocking antioxidant in step five is replaced with sodium citrate as a metal ion deactivator. The luminescent material is replaced with PVK-doped Ir(MDQ)₂(acac). That is, in Example 16, the luminescent layer uses PVK as the host luminescent material, Ir(MDQ)₂(acac) as the guest luminescent material, and sodium citrate as the antioxidant. The doping ratio of PVK, Ir(MDQ)₂(acac), and sodium citrate is 97.5%:2%:0.5%.

[0169] Example 17: This example is basically the same as Example 16, except that the doping ratio of PVK, Ir(MDQ)2(acac) and sodium citrate in the luminescent material in step five is 97%:2%:1%.

[0170] Example 18: This example is basically the same as Example 16, except that the doping ratio of PVK, Ir(MDQ)2(acac) and sodium citrate in the luminescent material in step five is 95%:2%:3%.

[0171] Example 19: This example is basically the same as Example 16, except that sodium citrate in the metal ion deactivator in step five is replaced with ethylenediaminetetraacetic acid.

[0172] Example 20: This example is basically the same as Example 17, except that sodium citrate in the metal ion deactivator in step five is replaced with ethylenediaminetetraacetic acid.

[0173] Example 21: This example is basically the same as Example 18, except that sodium citrate in the metal ion deactivator in step five is replaced with ethylenediaminetetraacetic acid.

[0174] Example 22: This example is basically the same as Example 16, except that the luminescent material in step five, Ir(MDQ)₂(acac), is replaced with Ir(ppy)₂(acac).

[0175] Example 23: This example is basically the same as Example 16, except that the luminescent material in step five, Ir(MDQ)2(acac), is replaced with Fir6.

[0176] Example 24: This example is basically the same as Example 16, except that the luminescent material in step five, Ir(MDQ)2(acac), is replaced with Phqlr.

[0177] Example 25: This example is basically the same as Example 16, except that the luminescent material in step five, Ir(MDQ)2(acac), is replaced with Ir(DPF)3.

[0178] Comparative Example 7: This comparative example is basically the same as Example 16, except that the light-emitting layer material in step five is PVK and Ir(MDQ)2(acac), the antioxidant material is sodium citrate, and the light-emitting layer material is Ir(MDQ)2(acac), and no antioxidant material is added.

[0179] Comparative Example 8: This comparative example is basically the same as Example 16, except that the light-emitting layer material in step five is PVK and Ir(MDQ)2(acac), the antioxidant material is sodium citrate, and the light-emitting layer material is Ir(ppy)2(acac), and no antioxidant material is added.

[0180] Comparative Example 9: This comparative example is basically the same as Example 16, except that the light-emitting layer material in step five is replaced with PVK and Ir(MDQ)2(acac), and the antioxidant material is replaced with sodium citrate. The light-emitting layer material is Fir6, and no antioxidant material is added.

[0181] Comparative Example 10: This comparative example is basically the same as Example 16, except that the light-emitting layer material in step five is PVK and Ir(MDQ)2(acac), the antioxidant material is sodium citrate, and the light-emitting layer material is Phqlr, and no antioxidant material is added.

[0182] Comparative Example 11: This comparative example is basically the same as Example 16, except that the light-emitting layer material in step five is PVK and Ir(MDQ)2(acac), the antioxidant material is sodium citrate, and the light-emitting layer material is Ir(DPF)3, and no antioxidant material is added.

[0183] The light-emitting devices prepared in Examples 16-18, 22-25, and Comparative Examples 7-11 were subjected to optical performance tests. The types of light-emitting materials and antioxidant materials, doping ratios, and test results of Examples 16-18, 22-25, and Comparative Examples 7-11 are shown in the table below.

[0184] Table 4: Sodium Citrate

[0185]

[0186] As shown in Table 4:

[0187] As shown in Examples 16-18 and Comparative Example 7, the driving voltage of the light-emitting devices in Examples 16-18 is lower than that in Comparative Example 7. The lower operating voltage helps reduce the device aging rate. The external quantum efficiency and lifetime of the light-emitting devices in Examples 16-18 are significantly improved compared to Comparative Example 7. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifetime of the light-emitting device.

[0188] As shown in Examples 22-25 and Comparative Examples 8-11, compared to Comparative Example 8, Example 23 compared to Comparative Example 9, Example 24 compared to Comparative Example 10, and Example 25 compared to Comparative Example 11, the driving voltage of the light-emitting device in Examples 22 is lower than that in the comparative examples. The lower operating voltage helps reduce the device aging rate. Furthermore, the external quantum efficiency and lifespan of the light-emitting devices in Examples 25 are significantly improved compared to the comparative examples. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifespan of the light-emitting device.

[0189] As can be seen from Examples 16-18, Examples 22-25, and Comparative Examples 7-11, the reduction in driving voltage and the improvement in external quantum efficiency and lifetime of the light-emitting device are influenced by both the doping ratio of the antioxidant material in the light-emitting layer 200 and the specific type of light-emitting material selected. If the specific type of light-emitting material is not matched with the doping ratio of the antioxidant material, the reduction in driving voltage and the improvement in external quantum efficiency and lifetime are not optimal. Therefore, the specific type of light-emitting material should be matched with the doping ratio of the antioxidant material. For example, if the light-emitting material is selected as... Ir(MDQ)2(acac) When the antioxidant material is selected as Phqlr, the doping ratio of the antioxidant material in the light-emitting layer 200 is 1%; when the light-emitting material is Phqlr, the doping ratio of the antioxidant material in the light-emitting layer 200 is 0.5%. By rationally selecting the type of light-emitting material and the doping ratio of the antioxidant, the manufacturing cost is reduced, a balance between performance improvement and cost control is achieved, and the best effect can be obtained.

[0190] The antioxidants in Examples 19-21 are selected from ethylenediaminetetraacetic acid (EDTA), one of the metal ion deactivators.

[0191] The light-emitting devices prepared in Examples 19-21 were subjected to optical performance tests. The types of light-emitting materials and antioxidant materials, doping ratios, and test results of Examples 19-21 and Comparative Example 7 are shown in the table below.

[0192] Table 5: Ethylenediaminetetraacetic acid (EDTA)

[0193]

[0194]

[0195] As shown in Table 5, based on Examples 19-21 and Comparative Example 7, the driving voltage of the light-emitting devices in Examples 19-21 is lower than that in Comparative Example 7. The lower operating voltage helps reduce the device aging rate. The external quantum efficiency and lifespan of the light-emitting devices in Examples 19-21 are significantly improved compared to Comparative Example 7. This demonstrates that doping the light-emitting layer 200 with antioxidant materials can reduce the interaction between oxygen and the triplet state of the light-emitting material, thereby reducing the exciton annihilation rate, improving the excitation efficiency of the quantum dots in the light-emitting device, and extending the lifespan of the light-emitting device.

[0196] As attached Figure 2 As shown, the JV curves of the light-emitting layer films prepared in Examples 1 to 25 and Comparative Examples 1 to 11 show that the current density gradually increases with the increase of voltage; when the output current density (i.e., 7 mA / cm²) is the same, the current density increases gradually. 2When the external quantum efficiency (EQE) of each embodiment is as follows: Embodiment 1: 11.0%, Embodiment 2: 11.4%, Embodiment 3: 10.7%, Embodiment 4: 11.1%, Embodiment 5: 11.6%, Embodiment 6: 10.8%, Embodiment 7: 9.9%, Embodiment 8: 10.0%, Embodiment 9: 8.9%, Embodiment 10: 9.3%, Embodiment 11: 10.9%, Embodiment 12: 10.7%, Embodiment 13: 11.0%, Embodiment 14: 10.4%, Embodiment 15: 10.0%, Embodiment 16: 9.8%, Embodiment 17: 9.3%, Embodiment 18: 9.5%, Embodiment 19: 10.3%, Embodiment 20: 10.3%, Embodiment 21: 9.4%, Embodiment 22: 8.9%, Embodiment 23: 11.4%, Embodiment 24: 11.9%, and Embodiment 25: 9.9%.

[0197] As attached Figure 3 As shown, the roughness of the light-emitting devices in Examples 1 to 25 is almost the same, indicating that the antioxidant and the light-emitting material are well miscible. This solves the problem in the prior art that some antioxidants may be incompatible with the organic materials in OLEDs, leading to reduced luminous efficiency or unstable device performance. This application selects two types, with two specific antioxidants in each type, and mixes them with the light-emitting material. The antioxidants effectively penetrate into the light-emitting layer 200, have good compatibility, and can remain stable during the use of the light-emitting device, providing a continuous protective effect. This effectively inhibits exciton annihilation in the light-emitting layer 200, thereby improving the luminous efficiency of the light-emitting device and extending its service life.

[0198] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A light-emitting device, characterized in that, It includes a first electrode, a light-emitting layer, and a second electrode stacked sequentially. The material of the light-emitting layer includes a light-emitting material and an antioxidant material; The antioxidant material is selected from one or more of chain-blocking antioxidants and metal ion deactivators.

2. The light-emitting device according to claim 1, characterized in that, The chain-blocking antioxidant is selected from organic amine compounds, phenolic compounds, vitamin C, vitamin E, carotenoids; and / or, The metal ion deactivator is selected from organic acids or organic acid salts.

3. The light-emitting device according to claim 2, characterized in that, The organic amine compounds include N-phenyl-N'-(1,3-dimethyl)butyl-p-phenylenediamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and diethanolamine; And / or, the phenolic compounds include catechol, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, catechins, and anthocyanins; And / or, the carotenoids include β-carotene, lutein, and zeaxanthin; And / or, the metal ion deactivator includes at least one of citric acid, ethylenediaminetetraacetic acid, di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate, citrate, ethylenediaminetetraacetic acid salt, and di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate; optionally, the citrate includes sodium citrate and potassium citrate; the ethylenediaminetetraacetic acid salt includes sodium ethylenediaminetetraacetic acid, sodium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate, and potassium di[methyl-{[2-(dimethylamino)ethyl]amino}methyl]phosphate.

4. The light-emitting device according to claim 1, characterized in that, The antioxidant material accounts for 0.1%-5% of the mass of the luminescent layer.

5. The light-emitting device according to claim 1, characterized in that, The antioxidant material is selected from the chain-blocking antioxidant, and the luminescent material is an organic luminescent material. Optionally, the organic luminescent material is selected from at least one of PTM, TTM, TTM-1CZ, PyBTM, PTM-3NCZ, and PS-CzTTM.

6. The light-emitting device according to claim 1, characterized in that, The antioxidant material is selected from the metal ion deactivator, and the luminescent material is a metal organic light-emitting material. Optionally, the metal organic light-emitting material is selected from at least one of Ir(MDQ)2(acac), Ir(ppy)2(acac), FIr6, Phqlr, and Ir(DPF)3.

7. The light-emitting device according to claim 6, characterized in that, The luminescent material further includes a host material, which is selected from blue light host materials. Optionally, the blue light host material is selected from at least one of PVK, mCP, CBP, CDBP, DCB, DCz, CBPCH, UGH3, BSB, SimCP, Czsi, TBCPF, PTC, BTPAF1, MP012, POAPF, 26DCzPPy, and P36EHF; and / or, The main material accounts for 90-99% of the mass of the light-emitting layer; and / or, The metal-organic luminescent material accounts for 0.05-5% of the mass of the luminescent layer.

8. The light-emitting device according to any one of claims 1-7, characterized in that, The thickness of the light-emitting layer is 20-40 nm; And / or, the light-emitting device further includes a hole functional layer located between the first electrode and the light-emitting layer; and / or, an electronic functional layer located between the second electrode and the light-emitting layer.

9. The light-emitting device according to claim 8, characterized in that, The first electrode and the second electrode are each independently selected from one or more of the following: metal electrode, silicon-carbon electrode, doped or undoped metal oxide electrode, and composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the silicon-carbon electrode is selected from at least one of silicon, graphite, carbon nanotubes, graphene, and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from ITO, FTO, ATO, AZO, GZO, and I ZnO, MZO, and AMO are selected as at least one of the following: 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, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or, The hole functional layer includes a hole transport layer and / or a hole injection layer. When the hole functional layer includes a hole injection layer and a hole transport layer, the hole injection layer is disposed adjacent to the first electrode, and the hole transport layer is disposed adjacent to the light-emitting layer. The material of the hole injection layer includes HATCN, PEDOT:PSS, BTDA-TCNQ, TDA-TCNNQ, TDA-TCNAQ, MeO-TAD, m-MTDATA, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4',4"-triphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, etc. (N-3-methylphenyl-N-phenylamino)triphenylamine, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], mixtures doped with 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone doped with N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4” diamine, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate The hole transport layer comprises one or more of the following: acid, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, transition metal oxides, and transition metal chalcogenides. The transition metal oxides are selected from one or more of NiO, MoO2, MoO3, WO3, and CuO. The transition metal chalcogenides are selected from one or more of MoS2, MoSe2, WS3, WSe3, and CuS. The material of the hole transport layer includes polymer hole transport materials and small molecule hole transport materials. One or more of the hole transport materials; the polymeric hole transport material is selected from one or more of poly(N-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl)amine] and poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butylphenyl)phenyl)-diphenylamine)]; the small molecule hole transport material is selected from one or more of 4,4',4”-tris(carbazole-9-yl)triphenylamine, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] and 4,4'-di(9-carbazole)biphenyl; and / or The electronic functional layer includes an electron transport layer and / or an electron injection layer. When the electronic functional layer includes an electron injection layer and an electron transport layer, the electron injection layer is disposed adjacent to the second electrode, and the electron transport layer is disposed adjacent to the light-emitting layer. The material of the electron transport layer is selected from tris(8-hydroxyquinoline)aluminum, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole, bis(10-hydroxybenzo[h]quinoline)beryllium, 3- (biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2,7-bis(diphenyloxyphosphino)-9,9'-spirodifluorene, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,6-bis(3,5-di(3-pyridinylphenyl)-2-methylpyrimidine, and 4,7-diphenyl-1,10-phenanthroline; the material of the electron injection layer is selected from at least one of Yb, yttrium fluoride, Li, LiF, NaF, CeF, CsCO3, Cs, KBH4, or KH.

10. A method for fabricating a light-emitting device, characterized in that, Includes the following steps: Provide substrate; A first electrode is formed on the substrate; A hole-functional layer is formed on the first electrode; A light-emitting layer doped with antioxidant material is formed on the hole functional layer; An electronic functional layer is formed on the light-emitting layer; A second electrode is formed on the electronic functional layer; The step of forming a light-emitting layer doped with an antioxidant material on the hole functional layer includes the following steps: incorporating the antioxidant material into the light-emitting material to form a doped ink; and depositing the ink on the hole functional layer using a solution method to form the light-emitting layer. The antioxidant material is selected from at least one or more of chain-blocking antioxidants and metal ion deactivators.

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