Trifluoromethyl substituted arylamine compound and application thereof

Abstract

The invention discloses an organic compound containing a trifluoromethyl-substituted arylamine group and application of the organic compound in an organic electroluminescent device. The compound disclosed by the invention is an organic compound containing trifluoromethyl substituted arylamine groups, has a relatively low visible light refractive index in the visible light field, and particularly has the refractive index of less than 1.60 in a blue light region (at the wavelength of 460 nm). Meanwhile, the compound disclosed by the invention has relatively high glass transition temperature (Tg is greater than 100 DEG C) and thermal stability. The compound is a low-refractive-index organic compound, is matched with a high-refractive-index material to form a composite light extraction layer structure, is applied to the organic electroluminescent device as a light extraction layer, and can effectively improve the light extraction efficiency and prolong the service life of the device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to an arylamine compound substituted with a trifluoromethyl group and its use as a light extraction layer material in an organic light-emitting device. Background Art

[0002] Organic Light Emission Diode (OLED) has characteristics such as high brightness, a wide range of material selection, low driving voltage, and full-curing active light emission. At the same time, it has advantages such as high definition, wide viewing angle, and high-speed response that can smoothly display animations, and it has been a popular research field in the past ten years or so. After years of development, great progress has been made. Although its internal quantum efficiency has approached 100%, the external quantum efficiency is only about 20%. Total reflection occurs at the interface between the ITO thin film and the glass substrate and at the interface between the glass substrate and the air. The light emitted to the front external space of the OLED device accounts for about 20% of the total quantum efficiency of the device, and the remaining about 80% of the light is mainly confined in the organic material thin film, the ITO thin film, and the glass substrate in the form of guided waves, seriously restricting the development and application of OLEDs. How to reduce the total reflection effect in the OLED device, increase the proportion of light coupled to the front external space of the device, and thus improve the performance of the device has attracted extensive attention.

[0003] In recent years, in order to improve the light extraction efficiency, some people have proposed to set a light extraction layer material with a high refractive index outside a semi-transparent electrode with a low refractive index to adjust the optical interference distance, suppress external light reflection, and suppress the extinction caused by the movement of surface plasmons, thereby improving the light extraction efficiency. Published patent documents such as CN106749132A, CN108976165A, CN110283143B, and CN112289952B continuously improve the refractive index of the light extraction layer by introducing a parent nucleus and branched chain groups containing a high refractive index to achieve the purpose of improving the device efficiency. However, the improvement degree of the light extraction efficiency of the device by this improved method is still not ideal, and most of the light is still trapped in the device and cannot escape. Moreover, the refractive index increase range of the high refractive index material is limited. Especially when the refractive index of the material is higher than 2.2 at 460 nm, it has become very difficult to improve the device efficiency by increasing the refractive index.

[0004] Therefore, to solve these problems, a double-light extraction layer structure has been proposed and achieved some results. By forming a stacked film structure with high / low refractive indices through light extraction layers with different refractive indices, a second resonant cavity is generated, enabling microcavity interference to occur when light emitted from within the device passes through the high / low refractive index film layers. As a result, light of a specific wavelength within the light emitted from the device can be emitted, enhancing the luminous intensity of the light of the specific wavelength and improving the luminous efficiency and lifespan of the device. Therefore, developing a low refractive index light extraction layer material to be paired with a high refractive index light extraction layer material to improve the device's luminous efficiency while ensuring the device's lifespan has important practical application value.

[0005] However, most of the existing low refractive index materials are inorganic materials or polymer materials, such as SiO2, PEDOT, etc., and their refractive indices are mostly less than 1.6 @ 460 nm. Currently, inorganic materials such as LiF are used as the low refractive index material in the light extraction layer, and its refractive index is less than 1.6 @ 460 nm. However, due to the poor flexibility of inorganic materials, the screen lifespan will be relatively low. Polymer materials cannot be vapor-deposited and can only be prepared by solution. The solution preparation method will damage the OLED device, significantly reducing its lifespan. Therefore, neither of these two materials is the best choice.

[0006] CN117362191 discloses the use of a low refractive index material containing an adamantane nucleus as the light extraction layer. Although its refractive index is less than 1.6 @ 460 nm, having a relatively low refractive index. However, due to the steric rigidity of adamantane, the glass transition temperature (Tg) of the compound is lower than 80 °C. During the long-term operation of the fabricated device, due to the existence of the thermal effect, phase separation occurs in the organic thin film, reducing the device efficiency and lifespan. At the same time, OLED devices require a high-temperature test at 85 °C, and this type of material cannot pass the high-temperature test.

[0007] CN111316461A discloses the use of a boron coordination compound as the light extraction layer material, which has a relatively low refractive index. However, the bonding strength of the coordination bond in its boron-containing coordination compound is much lower than that of a covalent bond, resulting in insufficient thermal stability. During the long-term operation of the material, due to the existence of the thermal effect, the material is prone to decomposition, leading to a reduction in device efficiency and lifespan.

[0008] Therefore, developing an organic light extraction layer material with a low refractive index, a high glass transition temperature, and high thermal stability, and pairing it with a light extraction layer of a high refractive index organic material to form a composite light extraction layer structure, thereby improving device efficiency and lifespan, is a long-term research direction and problem-solving approach in the OLED field. Summary of the Invention

[0009] In view of the above problems in the prior art, the present application provides an arylamine compound substituted with a trifluoromethyl group. By introducing a new parent nucleus structure, the compound of the present invention has a low refractive index, and at the same time has a high glass transition temperature (Tg > 100 °C) and thermal stability. It can be used as the first light extraction layer to form a composite light extraction layer structure with a second light extraction layer having a high refractive index, thereby effectively improving the light extraction efficiency and device lifetime of the device.

[0010] The technical solution provided by the present invention is as follows: An organic compound having a structure shown in the general formula (1):

[0011]

[0012] In the general formula (1), L independently represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, or a structure represented by any one of the general formulas (1-1) to (1-5);

[0013]

[0014] Each occurrence of X and Y is the same or different and each independently represents C-R5;

[0015] R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a cyano group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group;

[0016] m independently represents 1, 2, 3, 4, or 5;

[0017] n independently represents 0, 1, 2, 3, 4, or 5;

[0018] R1 and R2 independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a fluorine atom, or a trifluoromethyl group;

[0019] R3 and R4 independently represent a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group.

[0020] In a preferred embodiment, the organic compound has a structure shown in the general formulas (2-1) to (2-3)

[0021]

[0022] In the general formulas (2-1) to (2-3)

[0023] Each occurrence of X and Y is the same or different and each independently represents C-R5;

[0024] R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group;

[0025] m independently represents 1, 2, 3, 4 or 5;

[0026] n independently represents 0, 1, 2, 3, 4 or 5;

[0027] R1 and R2 independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a fluorine atom or a trifluoromethyl group. In a preferred embodiment, the compound has a structure represented by General Formula (3-1) to General Formula (3-6):

[0028]

[0029]

[0030] In General Formula (3-1) to General Formula (3-6)

[0031] Each occurrence of X and Y, which are the same or different, independently represents C-R5;

[0032] R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group or a tert-butyl group; m independently represents 1, 2, 3, 4 or 5;

[0033] n independently represents 0, 1, 2, 3, 4 or 5.

[0034] In a preferred embodiment, the compound has a structure represented by General Formula (4-1) to General Formula (4-2):

[0035]

[0036]

[0037] In General Formula (4-1) to General Formula (4-2)

[0038] Each occurrence of X and Y, which are the same or different, independently represents C-R5;

[0039] R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group or a tert-butyl group; m independently represents 1, 2, 3, 4 or 5;

[0040] n independently represents 0, 1, 2, 3, 4 or 5.

[0041] In a preferred embodiment, the specific structural formula of the organic compound is any one of the following structures:

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] The present invention also provides an organic electroluminescent device, which includes:

[0054] a substrate layer;

[0055] a first electrode, which is on the substrate layer;

[0056] an organic functional layer, which is on the first electrode;

[0057] a second electrode, which is on the organic functional layer;

[0058] and a light extraction layer on the second electrode;

[0059] The light extraction layer contains one or more of the organic compounds.

[0060] In a preferred embodiment, the light extraction layer includes a first light extraction layer and a second light extraction layer, and the first light extraction layer is on the second electrode;

[0061] The second light extraction layer is on the first light extraction layer;

[0062] The first light extraction layer contains one or more of the organic compounds.

[0063] Technical effects of the present invention:

[0064] The refractive index of the compound of the present invention in the blue light region (referring to 460 nm wavelength) is lower than 1.60. By introducing a new core structure and using trifluoromethyl-substituted arylamine as a side chain, the refractive index of the compound is effectively reduced. At the same time, the compound of the present invention has high thermal stability and glass transition temperature (Tg > 100 °C). The compound containing trifluoromethyl-substituted arylamine of the present invention belongs to a low refractive index organic material, and can be used as a first light extraction layer to form a composite light extraction layer with a high refractive index second light extraction layer and applied to OLED devices, which can improve the light extraction efficiency and lifespan of the devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic cross-sectional structure diagram of an application device structure of the compound of the present invention: Among them, 100 is a substrate, 200 is a first electrode, 300 is an organic functional layer, 400 is a second electrode, and 500 is a light extraction layer. Among them, 510 is a low refractive index first light extraction layer, and 520 is a high refractive index second light extraction layer.

[0066] Figure 2 is Figure 1 It is a schematic cross-sectional structure diagram of the organic functional layer 300: Among them, 310 is a hole injection layer, 320 is a hole transport layer, 330 is an electron blocking layer, 340 is a light emitting layer, 350 is a hole blocking layer, 360 is an electron transport layer, and 370 is an electron injection layer.

[0067] Figure 3 It is an attached drawing of the refractive indices of the compounds A03 and A54 in the synthesis examples at different wavelengths. DETAILED DESCRIPTION OF THE INVENTION

[0068] In this specification, unless explicitly described to the contrary, "including" any component will be understood to implicitly include other elements, rather than excluding any other elements. In addition, it should be understood that throughout this specification, when an element such as a layer, film, region, or substrate is referred to as being "on" or "above" another element, it may be "directly on" the other element, or there may also be intermediate elements. Additionally, "on" or "above" means located above the target part, and does not necessarily mean located above in the direction of gravity.

[0069] In this specification, the "n@460nm" used refers to the refractive index of the material relative to vacuum for blue light with a wavelength of 460 nm.

[0070] In a preferred embodiment of the present invention, an organic electroluminescent device is provided, which includes a substrate, an anode, a cathode, an organic functional layer, and a light extraction layer. The organic functional layer may include a light-emitting layer, a hole transport layer, a hole injection layer, an electron blocking layer, an electron transport layer, an electron injection layer, etc., or may only include a light-emitting layer and one or more other layers. The light extraction layer is composed of one or more of the trifluoromethyl-substituted arylamine compounds represented by the above general formula (1) or general formula (2-1) to general formula (2-3) or general formula (3-1) to general formula (3-6) or general formula (4-1) to general formula (4-2).

[0071] As Figure 1 shown, for the substrate 100, any substrate used in typical organic light-emitting devices can be selected. It can be a glass or transparent plastic substrate, or a substrate of an opaque material such as silicon or stainless steel, or a flexible PI film. Different substrates have different mechanical strengths, thermal stabilities, transparencies, surface smoothness, and waterproof properties, and are used in different directions according to the properties of the substrates.

[0072] A first electrode 200 is formed on the substrate 100. The first electrode 200 can be a cathode or an anode. Here, the first electrode 200 can be merely a reflective electrode, such as a reflective film formed of silver (Ag), magnesium (Mg), aluminum (Al), gold (Au), nickel (Ni), chromium (Cr), or an alloy thereof, or an electrode composed of a combination of a reflective film and a transparent or semi-transparent electrode. For example, a transparent or semi-transparent electrode layer with a high work function formed on the reflective film. The transparent or semi-transparent electrode layer can be formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum zinc oxide (AZO), indium gallium oxide (IGO), indium oxide (In2O3), or tin oxide (SnO2); or can be composed of a combination of a metal and an oxide, such as ITO / Ag / ITO, IGO / Al / IGO, or AZO / Ag / AZO.

[0073] As Figure 2As shown, the organic functional layer 300 may include a light-emitting layer 340 (EML). If the first electrode 200 is an anode, a hole-transporting region may be formed between the EML and the first electrode 200, and an electron-transporting region may be formed between the EML and the second electrode layer 400; if the first electrode 200 is a cathode, an electron-transporting region may be formed between the EML and the first electrode 200, and a hole-transporting region may be formed between the EML and the second electrode layer 400. The hole-transporting region may include at least one of a hole-injecting layer 310 (HIL), a hole-transporting layer 320 (HTL), and an electron-blocking layer 330 (EBL). The electron-transporting region may include at least one of a hole-blocking layer 350 (HBL), an electron-transporting layer 360 (ETL), and an electron-injecting layer 370 (EIL). Accordingly, the organic functional layer 300 includes a light-emitting layer and a combination of at least two layers among a hole-injecting layer, a hole-transporting layer, an electron-blocking layer, a hole-blocking layer, an electron-transporting layer, and an electron-injecting layer. The thickness of the organic functional layer 300 is 50 nm - 1000 nm.

[0074] As materials for the hole-injecting layer, the hole-transporting layer, and the electron-blocking layer (HIL 310, HTL 320, EBL 330), any material may be selected and used from known related materials for OLED devices. At least one of the HIL 310 and the HTL 320 may further include a charge-generation material for improving conductivity. The charge-generation material may be a p-dopant. Non-limiting compounds of the p-dopant include: quinone derivatives such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4-TCNQ); or hexaazatriphenylene derivatives such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN); or cyclopropane derivatives such as 4,4',4”-((1E,1'E,1”E)-cyclopropane-1,2,3-trimethylidynetris(cyanomethanylylidene))tris(2,3,5,6-tetrafluorobenzyl); or metal oxides such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0075] The EBL330 material can be a triarylamine derivative, a fluorene derivative, a spirofluorene derivative, a dibenzofuran derivative, a carbazole derivative, etc. Among them, triarylamine derivatives are preferred, such as N4,N4-bis([1,1'-biphenyl]-4-yl)-N4'-phenyl-N4'-[1,1':4',1''-terphenyl]-4-yl-[1,1'-biphenyl]-4,4'-diamine; spirofluorene derivatives, such as N-([1,1'-diphenyl]-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobifluorene-2-amine; dibenzofuran derivatives, such as N,N-bis([1,1'-biphenyl]-4-yl)-3'-(dibenz[b,d]furan-4-yl)-[1,1'-biphenyl]-4-amine, but not limited thereto.

[0076] In order to obtain a high-efficiency OLED device, the light-emitting layer 340 can use the same kind of doping material or multiple doping materials. The doping material can be a pure fluorescent material, a thermally activated delayed fluorescence (TADF) material or a phosphorescent material, or a combination of different fluorescent materials, TADF materials, and phosphorescent materials. The light-emitting layer 340 can be a single light-emitting layer material or a composite light-emitting layer material stacked horizontally or vertically.

[0077] As the host material of the light-emitting layer substance constituting the above OLED emitter, it not only needs to have bipolar charge transport characteristics, but also needs to have appropriate energy levels, and can effectively transfer the excitation energy generated by the recombination of electrons and holes to the guest light-emitting material, that is, the doping material. Such materials can be exemplified by styrylene arylidene derivatives, stilbene derivatives, carbazole derivatives, triarylamine derivatives, anthracene derivatives, pyrene derivatives, triazine derivatives, xanthenone derivatives, triphenylene derivatives, triazine derivatives, hexabenzocoronene derivatives, or bis(2-methyl-8-quinolinolato)(p-phenylphenolato)aluminum (BAlq), etc.

[0078] The materials for the hole blocking layer 350 and the electron transport layer 360 that make up the above OLED device can be selected from any materials with electron transport properties for OLEDs. Such materials include, for example, 1,3-bis[5'-(p-tert-butylphenyl)-1,3,4-oxadiazol-2'-yl]benzene, oxadiazole derivatives such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, triazole derivatives such as 3-(4'-tert-butylphenyl)-4-phenyl-5-(4''-biphenyl)-1,2,4-triazole, triazine derivatives, quinoline derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted indenone derivatives, thiopyran dioxide derivatives, anthraquinone dimethane derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthyl perylene, carbodiimide, inden derivatives, anthraquinone dimethane derivatives, anthrone derivatives, stilbenylpyrazine derivatives, silole derivatives, phenanthroline derivatives, or imidazopyridine derivatives, etc.

[0079] A second electrode 400 is formed on the organic functional layer 300. The second electrode layer can be a cathode or an anode, and can be a transparent electrode or a semi-transparent electrode. The second electrode 400 can be made of a thin film with a low work function formed by lithium, calcium, lithium fluoride / calcium, lithium fluoride / aluminum, aluminum, silver, magnesium, or their alloys. Further, the second electrode layer 400 can be made of an alloy including silver and at least one metal, and the at least one metal includes aluminum, platinum, ytterbium, chromium, or magnesium. And, the weight ratio of Ag in the alloy can be the same as, greater than, or less than the weight ratio of other metals. For example: The second electrode layer 400 can be formed of an Ag-Mg alloy, where the mass ratio of Ag and Mg can be from 90:10 to 10:90. Or, the second electrode layer 400 can be formed of an alloy including at least one metal such as silver, gold, platinum, copper, nickel, or tungsten and at least one metal such as ytterbium, indium, magnesium, or chromium. These metal films can form transparent or semi-transparent electrodes by adjusting the film thickness. Therefore, the light generated by the organic functional layer 300 can be emitted through the second electrode layer 400. And, the thickness of the second electrode layer 400 can be 5 - 20 nm.

[0080] A light extraction layer 500 is formed on the second electrode layer 400. The light extraction layer includes a first light extraction layer 510 and a second light extraction layer 520.

[0081] The material used for the first light extraction layer is an arylamine compound containing a trifluoromethyl substitution represented by the above general formula (1) or general formula (2-1) to general formula (2-3) or general formula (3-1) to general formula (3-6) or general formula (4-1) to general formula (4-2).

[0082] The second light extraction layer material usually has a relatively high refractive index, and its refractive index value at 460 nm in the blue light range is usually greater than 1.9. Specifically, aromatic amine derivatives, dibenzofuran derivatives, benzoxazole derivatives, benzothiazole derivatives, benzodibenzofuran derivatives, dibenzothiophene derivatives, benzodibenzothiophene derivatives, etc. can be selected.

[0083] The total film thickness of the light extraction layer of the present invention is 30 - 300 nm, preferably 40 nm - 100 nm, and most preferably 50 - 90 nm; the film thickness of the first light extraction layer is 10 - 120 nm, preferably 10 - 50 nm; the film thickness of the second light extraction layer is 10 - 120 nm, preferably 10 - 100 nm, and more preferably 20 - 90 nm; the film thickness of the second light extraction layer and the film thickness of the first light extraction layer may be the same or different.

[0084] Preparation of the compound of the present invention

[0085] Preparation Example 1 Compound A03

[0086] Synthesis of intermediate C-1:

[0087]

[0088] 1), Add 33.2 grams of raw material A-1, 1.4 grams of iron powder (Fe) and 50 ml of carbon tetrachloride (CCl4) to a 200 ml round-bottom flask equipped with a magnetic stir bar, a constant-pressure dropping funnel and a hydrogen bromide gas trap. Under stirring at room temperature, slowly add 14 ml of pure bromine (Br2) through the dropping funnel. After the addition is complete, stir for 2 hours, and detect by TLC on a TLC plate. After the raw material A-1 reacts completely, wash the reaction solution with a sodium bisulfite solution to remove the unreacted pure bromine, and extract the aqueous phase with dichloromethane. Combine the organic phases, wash the organic phases with a saturated sodium bicarbonate solution, filter at room temperature, and distill under reduced pressure. The concentrated oily substance is crystallized under high vacuum conditions to obtain intermediate A-1. LC-MS: Theoretical value: 487.92; Measured value: 488.99 ([M+H] + )

[0089] 2), Assemble a 250 mL round-bottom flask with a magnetic stir bar, reflux condenser, 250 mL constant-pressure dropping funnel, and rubber stopper, ensuring the system is airtight and gas-tight. Add 3.5 grams of magnesium powder (Mg) to the flask. Subsequently, flame-dry the system under nitrogen purge; after cooling, add a 150 ml anhydrous ether (Et2O) mixed solution containing 24.4 grams of intermediate A-1 to the flask through the constant-pressure dropping funnel. Under nitrogen protection, first add approximately 15 mL of the ether solution of intermediate A-1 to the magnesium strip. After the reaction is initiated, continue to slowly add the remaining ether solution of intermediate A-1 while maintaining a slight reflux state in the reaction system. After 3 hours, take a small amount of the reaction solution to quench it and analyze it by gas chromatography to determine that intermediate A-1 has completely reacted. After intermediate A-1 has completely reacted, cool the reaction solution to -78 °C. Subsequently, add dry HFA (hexafluoroacetone) to the continuously stirred solution through a syringe until the solution turns light yellow. Take a small amount of the reaction solution, quench it with dilute hydrochloric acid, extract it with ethyl acetate, and analyze it by gas chromatography. When the gas detection result shows that the content of intermediate B-1 reaches more than 80%, stop the reaction. Subsequently, restore the reaction system to atmospheric pressure at room temperature and let it stand for 2 hours. Pour the reaction solution into a separatory funnel containing saturated ammonium bromide, and then add dilute hydrochloric acid solution. After thorough shaking, separate the organic layer and wash it twice with 150 ml of saturated sodium bicarbonate solution and 150 ml of saturated sodium chloride solution in sequence. Concentrate the organic phase under reduced pressure and dry it under high vacuum for 24 hours to obtain intermediate B-1. LC-MS: Theoretical value: 664.07; Measured value: 665.18 ([M+H] + ).

[0090] 3), To a 250 mL round-bottom flask equipped with a mechanical stirrer, reflux condenser, and dropping funnel, add 6.64 grams of intermediate B-1, 29.0 grams of sodium chromate (Na2CrO4), and 50 ml of distilled water in sequence. Under stirring conditions, slowly add 40 ml of concentrated sulfuric acid through the dropping funnel. After the addition is complete, heat the mixture to a slight reflux state and continue the reaction for 48 hours. Take samples for TLC analysis on a TLC plate. After intermediate B-1 has completely reacted, let the reaction solution cool naturally to room temperature. Subsequently, pour the reaction solution into a separatory funnel containing 200 ml of distilled water and extract it three times with 40 ml of ethyl acetate. The combined organic extracts are washed twice with 300 ml of distilled water, once with 200 ml of saturated sodium bicarbonate solution, and once with 150 ml of saturated sodium chloride solution, concentrated under reduced pressure, and recrystallized with a mixed solution of ethyl acetate:toluene = 1:3 to obtain intermediate C-1. LC-MS: Theoretical value: 688.00; Measured value: 689.11 ([M+H] + ).

[0091] Synthesis reference: https: / / doi.org / 10.1021 / jo00301a044.

[0092] Synthesis of intermediate E-1:

[0093]

[0094] 1), into a 200 ml three-necked flask equipped with a mechanical stirrer, reflux condenser and nitrogen protection device, 0.02 mol of raw material B-1, 0.022 mol of raw material C-1, 4*10 -4 mol of tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), 1.8*10 -3 mol of bicyclic triaminophosphine (P(i-BuNCH2CH2)3N) and 0.03 mol of sodium tert-butoxide were added successively. 100 ml of toluene was added, and nitrogen was introduced to displace for 15 minutes. Subsequently, under a nitrogen atmosphere, stirring was started, and the system was heated to 80 °C and reacted for 20 hours. Sampling was carried out for TLC analysis. After the raw material B-1 was completely reacted, the reaction solution was naturally cooled to room temperature. Filtration was carried out, and the filtrate was subjected to vacuum distillation. The obtained crude product was recrystallized with a mixed solution of petroleum ether:toluene = 4:1 to obtain intermediate D-1. LC-MS: Theoretical value: 426.08; Measured value: 427.19 ([M+H] + ).

[0095] Synthesis reference: https: / / doi.org / 10.1021 / acs.organomet.8b00453.

[0096] 2), into a 200 ml three-necked flask equipped with a mechanical stirrer, reflux condenser and nitrogen protection device, 0.02 mol of intermediate D-1, 0.03 mol of hydrazine hydrate, 50 mL of tetrahydrofuran and 50 mL of ethanol were added and stirred and mixed. Then 2×10 -5 mol of Raney nickel was added to the flask, and the mixture was stirred and heated to reflux for 16 hours. Sampling was carried out for TLC analysis. After the raw material D-1 was completely reacted, the reaction solution was naturally cooled to room temperature. Filtration was carried out at room temperature, and the filtrate was subjected to rotary evaporation under reduced pressure and passed through a neutral silica gel column chromatography to obtain intermediate E-1. LC-MS: Theoretical value: 396.11; Measured value: 397.04 ([M+H] + ).

[0097] Synthesis reference: https: / / doi.org / 10.1016 / j.bmcl.2006.10.002.

[0098] Synthesis of compound A03:

[0099]

[0100] Into a 250 mL round-bottom flask equipped with a mechanical stirrer, a reflux condenser, and a dropping funnel, 0.02 mol of intermediate C-1, 0.022 mol of intermediate E-1, and 100 mL of N,N-dimethylformamide (DMF) were successively added. The system was purged with nitrogen for 15 minutes. Subsequently, under stirring, the reaction system was heated to reflux and reacted for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, and 100 mL of distilled water was added to precipitate the product. The mixture was filtered, and the filter cake was washed twice with 100 mL of absolute ethanol. The obtained crude product was recrystallized with a mixed solution of dichloromethane:toluene = 1:4, and the obtained product was subjected to silica gel column chromatography to obtain compound A03. Elemental analysis: Theoretical values: C, 52.37; H, 2.09; N, 3.88; Test values: C, 52.42; H, 2.05; N, 3.91;. LC-MS: Theoretical value: 1444.19; Measured value: 1445.06 ([M+H] + )。

[0101] Synthesis reference: https: / / doi.org / 10.1021 / cm202650u.

[0102] The following intermediates A, B, and C were synthesized by repeating the process of preparing intermediate C-1 in Example 1; the reaction conditions were the same, except that raw material A listed in Table 1 below was used.

[0103] Table 1

[0104]

[0105] Mass spectrometry characterization of intermediate A-2: LC-MS: Theoretical value: 387.93; Measured value: 388.96 ([M+H] + )。

[0106] Mass spectrometry characterization of intermediate B-2: LC-MS: Theoretical value: 564.08; Measured value: 565.20 ([M+H] + )。

[0107] Mass spectrometry characterization of intermediate C-2: LC-MS: Theoretical value: 588.00; Measured value: 589.13 ([M+H] + )。

[0108] Mass spectrometry characterization of intermediate A-3: LC-MS: Theoretical value: 337.93; Measured value: 338.99 ([M+H] + )。

[0109] Mass Spectrometry Characterization of Intermediate B-3: LC-MS: Theoretical value: 514.08; Measured value: 515.16 ([M+H] + )。

[0110] Mass Spectrometry Characterization of Intermediate C-3: LC-MS: Theoretical value: 538.01; Measured value: 539.08 ([M+H] + )。

[0111] Mass Spectrometry Characterization of Intermediate A-4: LC-MS: Theoretical value: 487.92; Measured value: 488.85 ([M+H] + )。

[0112] Mass Spectrometry Characterization of Intermediate B-4: LC-MS: Theoretical value: 664.07; Measured value: 665.14 ([M+H] + )。

[0113] Mass Spectrometry Characterization of Intermediate C-4: LC-MS: Theoretical value: 688.00; Measured value: 689.07 ([M+H] + )。

[0114] Mass Spectrometry Characterization of Intermediate A-5: LC-MS: Theoretical value: 353.93; Measured value: 354.86 ([M+H] + )。

[0115] Mass Spectrometry Characterization of Intermediate B-5: LC-MS: Theoretical value: 530.08; Measured value: 531.19 ([M+H] + )。

[0116] Mass Spectrometry Characterization of Intermediate C-5: LC-MS: Theoretical value: 554.00; Measured value: 555.06 ([M+H] + )。

[0117] Mass Spectrometry Characterization of Intermediate A-6: LC-MS: Theoretical value: 365.93; Measured value: 366.90 ([M+H] + )。

[0118] Mass Spectrometry Characterization of Intermediate B-6: LC-MS: Theoretical value: 542.08; Measured value: 543.14 ([M+H] + )。

[0119] Mass Spectrometry Characterization of Intermediate C-6: LC-MS: Theoretical value: 566.00; Measured value: 567.04 ([M+H] + )。

[0120] Repeat the process in Example 1 to synthesize the following Intermediate D and Intermediate E; the reaction conditions are the same, except that starting materials B and C listed in Table 2 below are used.

[0121] Table 2

[0122]

[0123]

[0124]

[0125] Mass spectrometry characterization of Intermediate D-2: LC-MS: Theoretical value: 562.06; Measured value: 563.12 ([M+H] + ). Mass spectrometry characterization of Intermediate E-2: LC-MS: Theoretical value: 532.08; Measured value: 533.18 ([M+H] + ).

[0126] Mass spectrometry characterization of Intermediate D-3: LC-MS: Theoretical value: 562.06; Measured value: 563.20 ([M+H] + ). Mass spectrometry characterization of Intermediate E-3: LC-MS: Theoretical value: 532.08; Measured value: 533.22 ([M+H] + ).

[0127] Mass spectrometry characterization of Intermediate D-4: LC-MS: Theoretical value: 698.03; Measured value: 699.10 ([M+H] + ). Mass spectrometry characterization of Intermediate E-4: LC-MS: Theoretical value: 668.06; Measured value: 669.12 ([M+H] + ).

[0128] Mass spectrometry characterization of Intermediate D-5: LC-MS: Theoretical value: 494.07; Measured value: 495.02 ([M+H] + ). Mass spectrometry characterization of Intermediate E-5: LC-MS: Theoretical value: 464.09; Measured value: 465.03 ([M+H] + ).

[0129] Mass spectrometry characterization of Intermediate D-6: LC-MS: Theoretical value: 494.07; Measured value: 495.13 ([M+H] + ). Mass spectrometry characterization of Intermediate E-6: LC-MS: Theoretical value: 464.09; Measured value: 465.17 ([M+H] + ).

[0130] Mass spectrometry characterization of intermediate D-7: LC-MS: Theoretical value: 494.07; Measured value: 495.19 ([M+H] + ). Mass spectrometry characterization of intermediate E-7: LC-MS: Theoretical value: 464.09; Measured value: 465.02 ([M+H] + ).

[0131] Mass spectrometry characterization of intermediate D-8: LC-MS: Theoretical value: 630.04; Measured value: 631.11 ([M+H] + ). Mass spectrometry characterization of intermediate E-8: LC-MS: Theoretical value: 600.07; Measured value: 601.14 ([M+H] + ).

[0132] Mass spectrometry characterization of intermediate D-9: LC-MS: Theoretical value: 630.04; Measured value: 631.20 ([M+H] + ). Mass spectrometry characterization of intermediate E-9: LC-MS: Theoretical value: 600.07; Measured value: 601.03 ([M+H] + ).

[0133] Mass spectrometry characterization of intermediate D-10: LC-MS: Theoretical value: 630.04; Measured value: 631.01 ([M+H] + ). Mass spectrometry characterization of intermediate E-10: LC-MS: Theoretical value: 600.07; Measured value: 601.16 ([M+H] + ).

[0134] Mass spectrometry characterization of intermediate D-11: LC-MS: Theoretical value: 630.04; Measured value: 631.09 ([M+H] + ). Mass spectrometry characterization of intermediate E-11: LC-MS: Theoretical value: 600.07; Measured value: 601.00 ([M+H] + ).

[0135] Mass spectrometry characterization of intermediate D-12: LC-MS: Theoretical value: 766.02; Measured value: 767.06 ([M+H] + ). Mass spectrometry characterization of intermediate E-12: LC-MS: Theoretical value: 736.04; Measured value: 737.19 ([M+H] + ).

[0136] Mass spectrometry characterization of intermediate D-13: LC-MS: Theoretical value: 562.06; Measured value: 563.02 ([M+H] + ). Mass spectrometry characterization of intermediate E-13: LC-MS: Theoretical value: 532.08; Measured value: 533.13 ([M+H] +)。

[0137] Mass spectrometry characterization of intermediate D-14: LC-MS: Theoretical value: 698.03; Measured value: 699.13 ([M+H] + )。Mass spectrometry characterization of intermediate E-14: LC-MS: Theoretical value: 668.06; Measured value: 669.21 ([M+H] + )。

[0138] Mass spectrometry characterization of intermediate D-15: LC-MS: Theoretical value: 580.05; Measured value: 581.12 ([M+H] + )。Mass spectrometry characterization of intermediate E-15: LC-MS: Theoretical value: 550.07; Measured value: 551.04 ([M+H] + )。

[0139] Mass spectrometry characterization of intermediate D-16: LC-MS: Theoretical value: 494.07; Measured value: 495.04 ([M+H] + )。Mass spectrometry characterization of intermediate E-16: LC-MS: Theoretical value: 464.09; Measured value: 465.06 ([M+H] + )。

[0140] Repeat the process in Preparation Example 1 to synthesize the following target compounds; the reaction conditions are the same, except that the intermediate C and intermediate E listed in Table 3 below are used, and the mass spectrometry data analysis of the target compounds.

[0141] Table 3

[0142] Intermediate C Intermediate E Target Compound Mass Spectrometry Analysis Data Intermediate C-1 Intermediate E-2 A15 <![CDATA[LC-MS: Theoretical value: 1716.14; Measured value: 1717.08 ([M+H] + )。]]> Intermediate C-1 Intermediate E-3 A20 <![CDATA[LC-MS: Theoretical value: 1716.14; Measured value: 1717.20 ([M+H] + )。]]> Intermediate C-1 Intermediate E-4 A29 <![CDATA[LC-MS: Theoretical value: 1988.09; Measured value: 1989.16 ([M+H] + )。]]> Intermediate C-1 Intermediate E-5 A44 <![CDATA[LC-MS: Theoretical value: 1580.16; Measured value: 1581.06 ([M+H] + )。]]> Intermediate C-1 Intermediate E-6 A48 <![CDATA[LC-MS: Theoretical value: 1580.16; Measured value: 1581.22 ([M+H] + )。]]> Intermediate C-1 Intermediate E-7 A54 <![CDATA[LC-MS: Theoretical value: 1580.16; Measured value: 1581.24 ([M+H] + )。]]> Intermediate C-1 Intermediate E-8 A63 <![CDATA[LC-MS: Theoretical value: 1852.11; Measured value: 1853.23 ([M+H] + )。]]> Intermediate C-1 Intermediate E-9 A71 <![CDATA[LC-MS: Theoretical value: 1852.11; Measured value: 1853.04 ([M+H] + )。]]> Intermediate C-1 Intermediate E-10 A80 <![CDATA[LC-MS: Theoretical value: 1852.11; Measured value: 1853.19 ([M+H] + )。]]> Intermediate C-1 Intermediate E-11 A83 <![CDATA[LC-MS: Theoretical value: 1852.11; Measured value: 1853.15 ([M+H] + )。]]> Intermediate C-1 Intermediate E-12 A90 <![CDATA[LC-MS: Theoretical value: 2124.06; Measured value: 2125.13([M+H] + )。]]> Intermediate C-1 Intermediate E-13 A102 <![CDATA[LC-MS: Theoretical value: 1716.14; Measured value: 1717.24 ([M+H] + )。]]> Intermediate C-1 Intermediate E-14 A116 <![CDATA[LC-MS: Theoretical value: 1988.09; Measured value: 1989.18 ([M+H] + )。]]> Intermediate C-1 Intermediate E-15 A121 <![CDATA[LC-MS: Theoretical value: 1752.12; Measured value: 1753.06 ([M+H] + )。]]> Intermediate C-2 Intermediate E-16 A129 <![CDATA[LC-MS: Theoretical value: 1480.17; Measured value: 1481.12 ([M+H] + )。]]> Intermediate C-5 Intermediate E-16 A132 <![CDATA[LC-MS: Theoretical value: 1446.17; Measured value: 1447.10 ([M+H] + )。]]> Intermediate C-6 Intermediate E-16 A135 <![CDATA[LC-MS: Theoretical value: 1458.17; Measured value: 1459.29 ([M+H] + )。]]> Intermediate C-3 Intermediate E-16 A141 <![CDATA[LC-MS: Theoretical value: 1430.17; Measured value: 1431.03 ([M+H] + )。]]> Intermediate C-4 Intermediate E-16 A144 <![CDATA[LC-MS: Theoretical value: 1580.16; Measured value: 1581.18 ([M+H] + )。]]>

[0143] The refractive index test method of the compound is as follows: The compound is deposited on a transparent quartz substrate by vacuum evaporation, placed in a glove box, and nitrogen is introduced. The refractive index curve of the compound is tested using an American J.A.Woollam M-2000 ellipsometer, and the refractive index n@460nm is the refractive index corresponding to the wavelength of 460nm; The glass transition temperature (Tg) of the material is tested using a PerkinElmer STA6000 type device. The test result data is shown in Table 4 below.

[0144] Table 4

[0145] Compound Refractive Index n@460nm Tg (°C) Compound Refractive Index n@460nm Tg (°C) A03 1.531 105 A83 1.468 111 A15 1.510 120 A90 1.497 125 A20 1.496 116 A102 1.511 119 A29 1.506 123 A116 1.495 116 A44 1.513 118 A121 1.472 124 A48 1.508 121 A129 1.563 110 A54 1.490 114 A132 1.571 112 A63 1.486 128 A135 1.582 117 A71 1.477 122 A141 1.534 118 A80 1.482 115 A144 1.546 112

[0146] From the test data in Table 4 above, it can be seen that the refractive index of the compound of the present invention in the blue light region (@460nm) is less than 1.60; the refractive index of some compounds is less than 1.50. The Tg of the compound is higher than 100 °C, and the Tg of some compounds is higher than 110 °C, having good thermal stability.

[0147] Device Embodiment

[0148] The beneficial technical effects of the compound of the present invention as a light extraction layer applied to an OLED device are further illustrated by the following device embodiments. The materials, equipment and test methods used in the embodiments are commercially purchased or synthesized by referring to the literature in the prior art.

[0149] The molecular structural formulas of the related materials are shown as follows:

[0150]

[0151] Structure of Device Embodiment 1: Substrate layer 100 / First electrode (anode) layer 200 (Ag (100 nm)) / Hole injection layer 310 (HTL-1:DP-1 = 96:4 mass ratio, thickness 10 nm) / Hole transport layer 320 (HTL-1, thickness 110 nm) / Electron blocking layer 330 (EBL-1, thickness 10 nm) / Light emitting layer 340 (BHL-1:BD-1 = 98:2 mass ratio, thickness 25 nm) / Hole blocking layer 350 (HBL-1, thickness 5 nm) / Electron transport layer 360 (ETL-1:LiQ = 4:6 mass ratio, thickness 30 nm) / Electron injection layer 370 (Yb, thickness 1 nm) / Second electrode (cathode) layer 400 (Mg:Ag = 1:9 mass ratio, thickness 18 nm) / First light extraction layer 510 (Compound A03 of the present invention, thickness 20 nm) / Second light extraction layer 520 (HCP-1, thickness 60 nm).

[0152] Fabrication method of Device Example 1: The transparent substrate layer 100 is transparent glass, the first electrode (anode) layer 200 is Ag (100 nm), and the first electrode (anode) layer 200 is washed to remove organic residues on the surface. After that, on the anode layer 2, HTL-1 and DP-1 with a film thickness of 10 nm are evaporated as the hole injection layer 310, and the mass ratio of HTL-1 to DP-1 is 96:4. Then, HTL-1 with a thickness of 110 nm is evaporated as the hole transport layer 320. Subsequently, EBL-1 with a thickness of 10 nm is evaporated as the electron blocking layer 330. Then, the light-emitting layer 340 is evaporated. Its structure uses BHL-1 as the host material and BD-1 as the doping material, and the doping ratio of the doping material is 2% by weight, and the film thickness of the light-emitting layer is 25 nm. After the above light-emitting layer 340, HBL-1 is continuously evaporated with a film thickness of 5 nm as the hole blocking layer 350. On the above hole blocking layer 350, ETL-1 and LiQ are continuously evaporated, and the mass ratio of ET-1 to LiQ is 4:6. The vacuum evaporation film thickness of this layer of material is 30 nm, and this layer is the electron transport layer 360. On the electron transport layer 360, a Yb layer with a film thickness of 1 nm is fabricated through a vacuum evaporation device, and this layer is the electron injection layer 370. On the electron injection layer 370, an Mg:Ag electrode layer with a film thickness of 18 nm is fabricated through a vacuum evaporation device, and the mass ratio of Mg to Ag is 1:9, and this layer is the second electrode (cathode) layer 400. On the cathode layer, the light extraction layer 500 is then evaporated. Among them, the compound A03 of the present invention with a vacuum evaporation film thickness of 20 m is used as the first light extraction layer 510; then, on the first light extraction layer, HCP-1 with a vacuum evaporation film thickness of 60 nm is continuously evaporated as the second light extraction layer 520.

[0153] Device Comparative Example

[0154] The structure and fabrication method of Device Comparative Example 1 are similar to those of Device Example 1, except that the composite light extraction layer is not used, and only a single-layer light extraction layer is used; 80 nm of the compound HCP-1 is evaporated as the material of the second light extraction layer, and the first light extraction layer is not evaporated.

[0155] The structure and fabrication method of Device Comparative Example 2 are similar to those of Device Example 1, except that the composite light extraction layer is not used, and only a single-layer light extraction layer is used; 80 nm of the compound A03 is evaporated as the material of the first light extraction layer, and the second light extraction layer is not evaporated.

[0156] The structure and fabrication method of Device Comparative Examples 3 to 7 are similar to those of Device Example 1, except that the material of the first light extraction layer uses a comparative compound.

[0157] The test results of the device structure (the first light extraction layer and the second light extraction layer), device performance (Index), and device lifetime are shown in Table 5. The data of the device under the condition of 10 mA / cm 2 shall be used as the standard (that is, the test values corresponding to when the test current density reaches 10 mA / cm 2 .

[0158] Table 5

[0159]

[0160]

[0161] Note: Index is obtained by dividing the current efficiency (cd / A) by CIEy, which is a well-recognized evaluation index for the performance of blue light devices in the industry. The Index (percentage) in Table 5 is the relative efficiency percentage; the device lifetime is the time required for the device brightness to decay to 97% of the initial brightness at a current density of 10 mA / cm 2 , and the lifetime (percentage) is the relative lifetime percentage.

[0162] The data in Table 5 show that compared with Comparative Example 1 of the device with only a high refractive index light extraction layer, the device performance (Index) of the device using the compound of the present invention as the composite light extraction layer with a low refractive index first light extraction layer and a high refractive index second light extraction layer is improved by more than 15%, and the lifetime is improved by more than 15%.

[0163] Compared with Comparative Example 2 of the device with only a low refractive index light extraction layer, the device performance (Index) of the device using the compound of the present invention as the composite light extraction layer with a low refractive index first light extraction layer and a high refractive index second light extraction layer is improved by more than 40%, and the lifetime is improved by more than 20%.

[0164] Compared with Device Comparative Examples 3 to 7, compared with Comparative Compounds 1 to 5, the device performance (Index) of the compound of the present invention is improved by more than 5%, and the device lifetime is improved by more than 10%. It shows that by changing the parent nucleus group of the compound and introducing a trifluoromethyl-substituted arylamine group as a side chain, the thermal stability and glass transition temperature of the compound are improved, thereby effectively improving the device efficiency and lifetime.

[0165] In summary, when the compound of the present invention is used as the first light extraction layer material and combined with a high refractive index second light extraction layer to prepare a composite light extraction layer and applied to an OLED device, the device performance can be effectively improved. At the same time, by changing the parent nucleus group of the compound and introducing a trifluoromethyl-substituted arylamine group as a side chain, the refractive index of the compound can be effectively reduced, the thermal stability and glass transition temperature of the compound can be improved, thereby effectively improving the device efficiency and lifetime.

[0166] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An organic compound, characterized in that, The organic compound has a structure represented by the general formula (1): In the general formula (1), L independently represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, or a structure represented by any one of the general formulas (1-1) to (1-5); Each occurrence of X and Y is the same or different and each independently represents C-R5; R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a cyano group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group; m independently represents 1, 2, 3, 4, or 5; n independently represents 0, 1, 2, 3, 4, or 5; R1 and R2 independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a fluorine atom, or a trifluoromethyl group; R3 and R4 independently represent a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group.

2. The organic compound according to claim 1, wherein the compound has a structure represented by the general formulas (2-1) to (2-3): In the general formulas (2-1) to (2-3) Each occurrence of X and Y is the same or different and each independently represents C-R5; R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group; m independently represents 1, 2, 3, 4, or 5; n independently represents 0, 1, 2, 3, 4, or 5; R1 and R2 independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a fluorine atom, or a trifluoromethyl group.

3. The organic compound according to claim 1 or 2, wherein the compound has a structure represented by the general formulas (3-1) to (3-6): In the general formulas (3-1) to (3-6) Each occurrence of X and Y is the same or different and each independently represents C-R5; R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group; m independently represents 1, 2, 3, 4, or 5; n independently represents 0, 1, 2, 3, 4, or 5.

4. The organic compound according to claim 1 or 2, wherein the compound has a structure represented by the general formulas (4-1) to (4-2): In the general formulas (4-1) to (4-2) Each occurrence of X and Y is the same or different and each independently represents C-R5; R5 independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a tert-butyl group; m independently represents 1, 2, 3, 4, or 5; n independently represents 0, 1, 2, 3, 4, or 5.

5. The organic compound according to claim 1, wherein The specific structural formula of the organic compound is any one of the following structures:

6. An organic electroluminescent device, the organic electroluminescent device comprising: Substrate layer; First electrode, which is on the substrate layer; Organic functional layer, which is on the first electrode; Second electrode, which is on the organic functional layer; And a light extraction layer on the second electrode; It is characterized in that the light extraction layer contains one or more of the organic compounds described in any one of claims 1-5.

7. The organic electroluminescent device according to claim 6: The light extraction layer includes a first light extraction layer and a second light extraction layer, the first light extraction layer being above the second electrode; the second light extraction layer being above the first light extraction layer; It is characterized in that The first light extraction layer contains one or more of the organic compounds described in any one of claims 1-6.

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