Organic electroluminescent material and application thereof

Abstract

The invention discloses an organic compound containing a trifluoromethyl group and application of the organic compound in an organic electroluminescent device. The compound provided by the invention is an organic compound containing a trifluoromethyl group, has a relatively low visible light refractive index in the visible light field, and particularly has a refractive index lower than 1.50 in a blue light region (at a wavelength of 460 nm), which is significantly lower than that of an existing light extraction layer material. Meanwhile, the compound disclosed by the invention has relatively high glass transition temperature (Tg is greater than 90 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 of the device and prolong the service life of the device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular, to an organic compound containing 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 the characteristics of high brightness, wide material selection range, low driving voltage, and full-curing active light emission. At the same time, it has the advantages of high definition, wide viewing angle, and high-speed response for smooth display of animations. 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 OLED. 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 the 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 increase the refractive index of the light extraction layer by introducing a mother 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 improvement 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@460nm, 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 some achievements have been made. By forming a stacked film structure of high / low refractive index through light extraction layers with different refractive indices, a second resonant cavity is generated, enabling microcavity interference of the light emitted from within the device through the high / low refractive index film layers, thereby emitting light of a specific wavelength from the light emitted within the device, 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 luminous efficiency of the device while ensuring the lifespan of the device has very 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 method, and the solution preparation method will damage the OLED device, significantly reducing the 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 spatial 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 thermal effects, 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 of 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 thermal effects, 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 enhancing the 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 existing in the prior art, the present application provides an organic compound containing a trifluoromethyl group. By introducing a new parent nucleus structure, the compound of the present invention has a low refractive index, a high glass transition temperature (Tg>90 °C) and thermal stability at the same time. It can be used as the first light extraction layer to form a composite light extraction layer structure with the second light extraction layer having a high refractive index, thereby effectively improving the light extraction efficiency and device life of the device.

[0010] The technical solution provided by the present invention is as follows: An organic compound, the organic compound has 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 shown in 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] n independently represents 0, 1 or 2;

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

[0018] m independently represents 0, 1, 2, 3, 4 or 5;

[0019] When n represents 0, at least one of X represents a trifluoromethyl-substituted carbon atom (which can be represented by C-CF3);

[0020] 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;

[0021] 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;

[0022] In a preferred embodiment, the organic compound has a structure shown in the general formulas (2-1) to (2-2)

[0023]

[0024]

[0025] In General Formula (2-1) and General Formula (2-2), L independently represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, or a structure represented by any one of General Formulas (1-1) to (1-5);

[0026]

[0027] Each occurrence of X and Y, which are the same or different, independently represents C-R5;

[0028] 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;

[0029] In General Formula (2-1), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3);

[0030] In General Formula (2-2), n independently represents 1 or 2;

[0031] p independently represents 1, 2, 3, 4, or 5;

[0032] m independently represents 0, 1, 2, 3, 4, or 5;

[0033] 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;

[0034] 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.

[0035] In a preferred embodiment, the organic compound is characterized in that: R1 and R2 independently represent a fluorine atom or a trifluoromethyl group; R5 independently represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

[0036] In a preferred embodiment, the compound has a structure represented by General Formulas (3-1) to (3-6):

[0037]

[0038]

[0039] In General Formulas (3-1) to (3-6)

[0040] Each occurrence of X and Y, which are the same or different, independently represents C-R5;

[0041] 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;

[0042] In General Formulas (3-1) to (3-3), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3); in General Formulas (3-4) to (3-6), n independently represents 1 or 2;

[0043] p independently represents 1, 2, 3, 4, or 5;

[0044] m independently represents 0, 1, 2, 3, 4, or 5;

[0045] 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;

[0046] In a preferred embodiment, the compound has a structure shown in General Formulas (4-1) to (4-10):

[0047]

[0048]

[0049] In General Formulas (4-1) to (4-10)

[0050] Each occurrence of X and Y, which may be the same or different, independently represents C-R5;

[0051] 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;

[0052] In General Formulas (4-1) to (4-5), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3); in General Formulas (4-6) to (4-10), n independently represents 1 or 2;

[0053] p independently represents 1, 2, 3, 4, or 5;

[0054] m independently represents 0, 1, 2, 3, 4, or 5;

[0055] In a preferred embodiment, the compound has a structure shown in General Formulas (5-1) to (5-3):

[0056]

[0057] In General Formulas (5-1) to (5-3)

[0058] Each occurrence of X and Y, which may be the same or different, independently represents C-R5;

[0059] 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;

[0060] In general formula (5-1), at least one of the X represents a carbon atom substituted with a trifluoromethyl group (which can be represented by C-CF3);

[0061] p independently represents 1, 2, 3, 4, or 5;

[0062] m independently represents 0, 1, 2, 3, 4, or 5;

[0063] In a preferred embodiment, the specific structural formula of the organic compound is any one of the following structures:

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] The present invention also provides an organic electroluminescent device, which includes:

[0082] A substrate layer;:

[0083] A first electrode, which is on the substrate layer;

[0084] An organic functional layer, which is above the first electrode;

[0085] A second electrode, which is above the organic functional layer;

[0086] And a light extraction layer is above the second electrode;

[0087] The light extraction layer contains one or more of the organic compounds containing a trifluoromethyl group.

[0088] Preferably, the light extraction layer includes a first light extraction layer and a second light extraction layer, and the first light extraction layer is above the second electrode;

[0089] The second light extraction layer is above the first light extraction layer;

[0090] The first light extraction layer contains one or more of the organic compounds containing a trifluoromethyl group.

[0091] Technical effects of the present invention:

[0092] The compound of the present invention has a refractive index lower than 1.50 in the blue light region (referring to 460 nm in wavelength). By introducing a new parent nucleus structure, 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. It can be used as the first light extraction layer to form a composite light extraction layer with a second light extraction layer having a high refractive index and applied to OLED devices, which can improve the light extraction efficiency and lifespan of the devices. Description of the drawings

[0093] Figure 1 It is a schematic cross-sectional structure diagram of an application device structure of the compound of the present invention: wherein, 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 first light extraction layer with a low refractive index, and 520 is a second light extraction layer with a high refractive index.

[0094] Figure 2 is Figure 1 A schematic cross-sectional structure diagram of the organic functional layer 300 in : wherein, 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.

[0095] Figure 3 It is an attached drawing of the refractive indices of the synthetic example compounds A09 and B50 at different wavelengths. Detailed implementation manners

[0096] In this specification, unless explicitly described to the contrary, "including" any component shall be understood as implicitly including other elements, rather than excluding any other elements. In addition, it should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "above" another element, it can be "directly on" the other element, or there can 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.

[0097] In this specification, the "n@460nm" used refers to the refractive index data of the material at a wavelength of 460 nm with respect to vacuum.

[0098] 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 organic compounds containing a trifluoromethyl group represented by the above general formula (1), general formula (2-1), general formula (2-2), general formula (3-1) to general formula (3-6), general formula (4-1) to general formula (4-10), or general formula (5-1) to general formula (5-3).

[0099] As Figure 1 shown, for the substrate 100, any substrate used in a typical organic light-emitting device 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 water resistances, and are used in different directions according to the properties of the substrates.

[0100] 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 can be an electrode formed by combining a reflective film and a transparent or semi-transparent electrode, for example, a transparent or semi-transparent electrode layer having a high work function and 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 formed by combining a metal and an oxide, for example, formed of ITO / Ag / ITO, IGO / Al / IGO, or AZO / Ag / AZO.

[0101] AsFigure 2 As shown, the organic functional layer 300 may include a light-emitting layer 340 (EML). If the first electrode 200 is an anode, a hole transport region may be formed between the EML and the first electrode 200, and an electron transport region may be formed between the EML and the second electrode layer 400; if the first electrode 200 is a cathode, an electron transport region may be formed between the EML and the first electrode 200, and a hole transport region may be formed between the EML and the second electrode layer 400. The hole transport region may include at least one of a hole injection layer 310 (HIL), a hole transport layer 320 (HTL), and an electron blocking layer 330 (EBL). The electron transport region may include at least one of a hole blocking layer 350 (HBL), an electron transport layer 360 (ETL), and an electron injection layer 370 (EIL). Therefore, the organic functional layer 300 includes a light-emitting layer and a combination of at least two layers among a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer. The thickness of the organic functional layer 300 is 50 nm - 1000 nm.

[0102] As materials for the hole injection layer, the hole transport layer, and the electron blocking layer (HIL 310, HTL 320, EBL 330), any material can be selected from known related materials for OLED devices for use. At least one of HIL 310 and 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 such as: 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-trimethylenetri(cyanomethylene))tris(2,3,5,6-tetrafluorobenzyl); or metal oxides such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0103] 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.

[0104] 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.

[0105] 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 stilbenylarylene 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.

[0106] The materials constituting the hole blocking layer 350 and the electron transport layer 360 of the OLED device can be any materials selected from materials used for OLEDs that have electron transport properties. Examples of such materials include oxadiazole derivatives such as 1,3-bis[5'-(p-tert-butylphenyl)-1,3,4-oxadiazole-2'-yl]benzene, 2-(4-biphenyl)-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 quinone derivatives, thiopyran dioxide derivatives, anthraquinone dimethane derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthyl perylene, carbodiimides, quinone derivatives, anthraquinone dimethane derivatives, anthrone derivatives, distyrylpyrazine derivatives, silpentadiene derivatives, phenanthroline derivatives or imidazopyridine derivatives.

[0107] 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 made of lithium, calcium, lithium fluoride / calcium, lithium fluoride / aluminum, aluminum, silver, magnesium or an alloy thereof. Further, the second electrode layer 400 can be made of an alloy including silver and at least one metal, wherein the at least one metal includes aluminum, platinum, ytterbium, chromium or magnesium. Moreover, the weight ratio of Ag in the alloy can be the same as that of other metals or greater than or less than the weight of other metals. For example: the second electrode layer 400 can be formed of an Ag-Mg alloy, wherein the mass ratio of Ag to Mg can be 90:10 to 10:90. Alternatively, 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 thickness of the film. Therefore, the light generated by the organic functional layer 300 can be emitted through the second electrode layer 400. Also, the second electrode layer 400 may have a thickness of 5-20 nm.

[0108] The light extraction layer 500 is formed on the second electrode layer 400 , and the light extraction layer includes a first light extraction layer 510 and a second light extraction layer 520 .

[0109] The material used for the first light extraction layer is an organic compound containing a trifluoromethyl group represented by the above-mentioned general formula (1) or general formula (2-1) or general formula (2-2) or general formula (3-1) to general formula (3-6) or general formula (4-1) to general formula (4-10) or general formula (5-1) to general formula (5-3).

[0110] 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.

[0111] 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 can be the same or different.

[0112] Preparation of the compound of the present invention

[0113] Preparation Example 1 Compound A09

[0114]

[0115] Into a 200 ml round-bottom flask equipped with a magnetic stir bar, a constant-pressure dropping funnel, and a hydrogen bromide gas trap, add 33.2 grams of raw material A-1, 1.4 grams of iron powder (Fe), and 50 ml of carbon tetrachloride (CCl4). While 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 has completely reacted, 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] + )

[0116] A 250 mL round-bottom flask was equipped with a magnetic stir bar, a reflux condenser, a 250 mL pressure-equalizing dropping funnel and a rubber stopper to ensure that the system was airtight and gas-tight. 3.5 g of magnesium powder (Mg) was added to the flask. Subsequently, the system was flame-dried under nitrogen purge; after cooling, a mixed solution of 150 ml of anhydrous diethyl ether (Et2O) containing 24.4 g of intermediate A-1 was added to the flask through the pressure-equalizing dropping funnel. Under nitrogen protection, about 15 mL of the diethyl ether solution of intermediate A-1 was first added dropwise to the magnesium strip. After the reaction was initiated, the remaining diethyl ether solution of intermediate A-1 was continuously added dropwise slowly, and the reaction system was maintained in a slightly reflux state. After 3 hours, a small amount of the reaction solution was quenched and analyzed by gas chromatography to determine that intermediate A-1 had completely reacted. After intermediate A-1 had completely reacted, the reaction solution was cooled to -78 °C. Subsequently, dry HFA (hexafluoroacetone) was added to the continuously stirred solution through a syringe until the solution turned light yellow. A small amount of the reaction solution was quenched with dilute hydrochloric acid, extracted with ethyl acetate, and analyzed by gas chromatography. When the gas detection result showed that the content of intermediate B-1 reached more than 80%, the reaction was stopped. Subsequently, the reaction system was restored to atmospheric pressure at room temperature and allowed to stand for 2 hours. The reaction solution was poured into a separating funnel containing saturated ammonium bromide, and dilute hydrochloric acid solution was added. After thorough shaking, the organic layer was separated and washed twice with 150 ml of saturated sodium bicarbonate solution and 150 ml of saturated sodium chloride solution in sequence. The organic phase was concentrated by distillation under reduced pressure and dried under high vacuum for 24 hours to obtain intermediate B-1. LC-MS: theoretical value: 664.07; measured value: 665.18 ([M+H] + ).

[0117] To a 250 mL round-bottom flask equipped with a mechanical stirrer, a reflux condenser and a dropping funnel, 6.64 g of intermediate B-1, 29.0 g of sodium chromate (Na2CrO4) and 50 ml of distilled water were added successively. Under stirring conditions, 40 ml of concentrated sulfuric acid was slowly added dropwise through the dropping funnel. After the addition was complete, the mixture was heated to a slightly reflux state and the reaction was continued for 48 hours. Sampling was carried out for TLC analysis. After intermediate B-1 had completely reacted, the reaction solution was naturally cooled to room temperature. Subsequently, the reaction solution was poured into a separating funnel containing 200 ml of distilled water and extracted three times with 40 ml of ethyl acetate. The combined organic extracts were 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] + ).

[0118] Into a 250 mL round-bottom flask equipped with a mechanical stirrer, a reflux condenser, and a dropping funnel, 13.8 g (0.02 mol) of intermediate C-1, 5.04 g (0.022 mol) of raw material B-1, and 100 mL of N,N-dimethylformamide (DMF) were added successively. 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 rinsed 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 chromatography on a silica gel column to obtain compound A09. Elemental analysis: Theoretical values: C, 42.18; H, 1.09; N, 2.52; Measured values: C, 42.35; H, 1.12; N, 2.48. LC-MS: Theoretical value: 1110.04; Measured value: 1111.10 ([M+H] + )。

[0119] Synthesis reference: https: / / doi.org / 10.1021 / jo00301a044; https: / / doi.org / 10.1021 / cm202650u.

[0120] Preparation Example 2 Compound A20

[0121]

[0122] Into a 250 mL round-bottom flask equipped with a mechanical stirrer, a reflux condenser, and a dropping funnel, 13.8 g (0.02 mol) of intermediate C-1, 5.43 g (0.022 mol) of raw material B-14, and 100 mL of N,N-dimethylformamide (DMF) were added successively. 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 the product was precipitated by adding 100 mL of distilled water. The mixture was filtered, and the filter cake was rinsed 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 chromatography on a silica gel column to obtain compound A20. Elemental analysis: Theoretical values: C, 40.86; H, 0.88; N, 2.44;; Measured values: C, 40.95; H, 0.91; N, 2.39. LC-MS: Theoretical value: 1146.02; Measured value: 1147.11 ([M+H] + )。

[0123] Preparation Example 3 Compound B06

[0124]

[0125] In a dry 100 mL round-bottom flask, add 1.78 g of raw material C-1, 5.53 g of potassium carbonate, and 0.06 g of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4). Dissolve the mixture in 30 mL of toluene, 20 mL of distilled water, and 10 mL of ethanol. Subsequently, add 2.92 g of raw material B-2, heat the mixture to reflux, and stir the reaction for 18 hours. Take a sample for TLC analysis. After the raw material B-2 has completely reacted, cool the mixture to room temperature. Quench the two-phase solution by adding 100 mL of saturated ammonium chloride solution and 100 mL of dichloromethane. After liquid separation, extract the aqueous phase twice with 100 mL of dichloromethane. Combine the organic phases and wash them successively with 100 mL of distilled water and 100 mL of saturated sodium bicarbonate solution. Dry the organic phase over sodium sulfate, filter, and distill the filtrate under reduced pressure to obtain a brown oil. Purify it by silica gel column chromatography on a chromatographic column to obtain intermediate D-1. LC-MS: Theoretical value: 305.06; Measured value: 306.11 ([M+H] + )。

[0126] Into a 250 mL round-bottom flask equipped with a mechanical stirrer, a reflux condenser, and a dropping funnel, successively add 13.8 g (0.02 mol) of intermediate C-1, 6.71 g (0.022 mol) of intermediate D-1, and 100 mL of N,N-dimethylformamide (DMF). Purge with nitrogen for 15 minutes. Subsequently, while stirring, heat the reaction system to reflux and react for 24 hours. After the reaction is completed, cool the mixture to room temperature and precipitate the product by adding 100 mL of distilled water. Filter, wash the filter cake twice with 100 mL of absolute ethanol, recrystallize the obtained crude product with a mixture of dichloromethane:toluene = 1:4, and subject the obtained product to silica gel column chromatography on a chromatographic column to obtain compound B06. Elemental analysis: Theoretical value: C, 48.51; H, 1.60; N, 2.22; Test value: C, 48.49; H, 1.57; N, 2.25. LC-MS: Theoretical value: 1262.10; Measured value: 1263.08 ([M+H] + )。

[0127] Synthesis references: https: / / doi.org / 10.1021 / jo9002536; https: / / doi.org / 10.1021 / cm202650u.

[0128] Repeat the processes in Preparation Examples 1 to 3 to synthesize the following intermediates A, B, and C; the reaction conditions are the same, except that the raw material A listed in Table 1 below is used.

[0129] Table 1

[0130]

[0131]

[0132] Mass spectrometry characterization of intermediate A-2: LC-MS: Theoretical value: 387.93; Measured value: 388.96 ([M+H] + )。

[0133] Mass spectrometry characterization of intermediate B-2: LC-MS: Theoretical value: 564.08; Measured value: 565.20 ([M+H] + )。

[0134] Mass spectrometry characterization of intermediate C-2: LC-MS: Theoretical value: 588.00; Measured value: 589.13 ([M+H] + )。

[0135] Mass spectrometry characterization of intermediate A-3: LC-MS: Theoretical value: 337.93; Measured value: 338.99 ([M+H] + )。

[0136] Mass spectrometry characterization of intermediate B-3: LC-MS: Theoretical value: 514.08; Measured value: 515.16 ([M+H] + )。

[0137] Mass spectrometry characterization of intermediate C-3: LC-MS: Theoretical value: 538.01; Measured value: 539.08 ([M+H] + )。

[0138] Mass spectrometry characterization of intermediate A-4: LC-MS: Theoretical value: 787.90; Measured value: 788.85 ([M+H] + )。

[0139] Mass spectrometry characterization of intermediate B-4: LC-MS: Theoretical value: 964.05; Measured value: 965.01 ([M+H] + )。

[0140] Mass spectrometry characterization of intermediate C-4: LC-MS: Theoretical value: 987.98; Measured value: 988.87 ([M+H] + )。

[0141] Mass spectrometry characterization of intermediate A-5: LC-MS: Theoretical value: 353.93; Measured value: 354.86 ([M+H] + )。

[0142] Mass spectrometry characterization of intermediate B-5: LC-MS: Theoretical value: 530.08; Measured value: 531.19 ([M+H] + )。

[0143] Mass spectrometry characterization of intermediate C-5: LC-MS: Theoretical value: 554.00; Measured value: 555.06 ([M+H] + ).

[0144] Mass spectrometry characterization of intermediate A-6: LC-MS: Theoretical value: 365.93; Measured value: 366.90 ([M+H] + ).

[0145] Mass spectrometry characterization of intermediate B-6: LC-MS: Theoretical value: 542.08; Measured value: 543.14 ([M+H] + ).

[0146] Mass spectrometry characterization of intermediate C-6: LC-MS: Theoretical value: 566.00; Measured value: 567.04 ([M+H] + ).

[0147] Repeat the processes in Preparation Examples 1 to 3 to synthesize the following intermediate D; the reaction conditions are the same, except that raw materials B and C listed in Table 2 below are used.

[0148] Table 2

[0149]

[0150]

[0151] Mass spectrometry characterization of intermediate D-2: LC-MS: Theoretical value: 373.05; Measured value: 374.12 ([M+H] + ).

[0152] Mass spectrometry characterization of intermediate D-3: LC-MS: Theoretical value: 373.05; Measured value: 374.09 ([M+H] + ).

[0153] Mass spectrometry characterization of intermediate D-4: LC-MS: Theoretical value: 373.05; Measured value: 374.20 ([M+H] + ).

[0154] Mass spectrometry characterization of intermediate D-5: LC-MS: Theoretical value: 373.05; Measured value: 374.02 ([M+H] + ).

[0155] Mass spectrometry characterization of intermediate D-6: LC-MS: Theoretical value: 373.05; Measured value: 374.11 ([M+H] + ).

[0156] Mass spectrometry characterization of intermediate D-7: LC-MS: Theoretical value: 373.05; Measured value: 374.17 ([M+H] + )

[0157] Mass spectrometry characterization of intermediate D-8: LC-MS: Theoretical value: 373.05; Measured value: 374.03 ([M+H] + )

[0158] Mass spectrometry characterization of intermediate D-9: LC-MS: Theoretical value: 373.05; Measured value: 374.22 ([M+H] + )

[0159] Mass spectrometry characterization of intermediate D-10: LC-MS: Theoretical value: 373.05; Measured value: 374.15 ([M+H] + )

[0160] Mass spectrometry characterization of intermediate D-11: LC-MS: Theoretical value: 441.04; Measured value: 442.11 ([M+H] + )

[0161] Mass spectrometry characterization of intermediate D-12: LC-MS: Theoretical value: 441.04; Measured value: 442.09 ([M+H] + )

[0162] Mass spectrometry characterization of intermediate D-13: LC-MS: Theoretical value: 441.04; Measured value: 442.18 ([M+H] + )

[0163] Mass spectrometry characterization of intermediate D-14: LC-MS: Theoretical value: 441.04; Measured value: 442.01 ([M+H] + )

[0164] Mass spectrometry characterization of intermediate D-15: LC-MS: Theoretical value: 381.10; Measured value: 382.05 ([M+H] + )

[0165] Mass spectrometry characterization of intermediate D-16: LC-MS: Theoretical value: 517.07; Measured value: 518.03 ([M+H] + )

[0166] Mass spectrometry characterization of intermediate D-17: LC-MS: Theoretical value: 517.07; Measured value: 518.21 ([M+H] + )

[0167] Mass spectrometry characterization of intermediate D-18: LC-MS: Theoretical value: 387.07; Measured value: 388.15 ([M+H]+ )。

[0168] Mass spectrometry characterization of intermediate D-19: LC-MS: Theoretical value: 373.05; Measured value: 374.16 ([M+H] + )。

[0169] Repeat the processes in Preparation Examples 1 to 3 to synthesize the following target compounds; the reaction conditions are the same, except that the intermediates C and D or raw materials listed in Table 3 below are used, and the mass spectrometry data analysis of the target compounds is performed.

[0170] Table 3

[0171]

[0172]

[0173] The refractive index test method of the compound is as follows: The compound is vacuum-evaporated onto a transparent quartz substrate, 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 are shown in Table 4 below.

[0174] Table 4

[0175] Compound Refractive index n@460nm Tg (°C) Compound Refractive index n@460nm Tg (°C) Compound A09 1.435 96 Compound B89 1.460 113 Compound A20 1.424 98 Compound B97 1.475 112 Compound B06 1.418 105 Compound B100 1.429 115 Compound B17 1.430 110 Compound B134 1.457 116 Compound B33 1.448 109 Compound C03 1.470 121 Compound B50 1.450 106 Compound C12 1.439 125 Compound B54 1.461 103 Compound C25 1.464 123 Compound B57 1.453 102 Compound D01 1.502 95 Compound B62 1.419 104 Compound D05 1.513 99 Compound B69 1.420 107 Compound D23 1.496 106 Compound B72 1.438 108 Compound D31 1.510 114 Compound B80 1.444 111 Compound D32 1.509 118 Compound E12 1.459 108 - - -

[0176] It can be seen from the test data in Table 4 above that the refractive index of the compound of the present invention in the blue light region (@460nm) is lower than 1.55; some compounds are lower than 1.50; the Tg of the compound is higher than 95°C, and the Tg of some compounds is higher than 105°C, having good thermal stability.

[0177] Device Example

[0178] The following device examples are used to further illustrate the beneficial technical effects of the compound of the present invention as a light extraction layer applied in OLED devices. The materials, equipment and test methods used in the examples are commercially purchased or synthesized by referring to the literature in the prior art.

[0179] The molecular structural formulas of the related materials are shown as follows:

[0180]

[0181]

[0182] Structure of Device Example 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 A09 of the present invention, thickness 20 nm) / Second light extraction layer 520 (HCP-1, thickness 60 nm).

[0183] Fabrication method of Device Example 1: The transparent substrate layer 100 is transparent glass, and the first electrode (anode) layer 200 is Ag (100 nm). The first electrode (anode) layer 200 is washed to remove organic residues on the surface. Then, HTL-1 and DP-1 with a thickness of 10 nm are evaporated on the anode layer 2 as the hole injection layer 310, and the mass ratio of HTL-1 and 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 and 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 by a vacuum evaporation device, and this layer is the electron injection layer 370. On the electron injection layer 370, a Mg:Ag electrode layer with a film thickness of 18 nm is fabricated by a vacuum evaporation device, and the mass ratio of Mg and 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, Compound A09 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.

[0184] Device Comparative Example

[0185] The structure and manufacturing method of Device Comparative Example 1 are similar to those of Device Example 1, except that instead of using a composite light extraction layer, only a single-layer light extraction layer is used; 80 nm of Compound HCP-1 is vapor-deposited as the second light extraction layer material, and the first light extraction layer is not vapor-deposited.

[0186] The structure and manufacturing method of Device Comparative Example 2 are similar to those of Device Example 1, except that instead of using a composite light extraction layer, only a single-layer light extraction layer is used; 80 nm of Compound A09 is vapor-deposited as the first light extraction layer material, and the second light extraction layer is not vapor-deposited.

[0187] The structures and manufacturing methods of Device Comparative Examples 3 to 9 are similar to those of Device Example 1, except that the material of the first light extraction layer uses a comparative compound.

[0188] 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 (i.e., the test value corresponding to when the test current density reaches 10 mA / cm 2 .

[0189] Table 5

[0190] Device code First light extraction layer / nm Second light extraction layer / nm Index (percentage) Lifetime (percentage) Device Example 1 Compound A09 / 20nm HCP-1 / 60nm 104.4％ 99.2％ Device Example 2 Compound A20 / 20nm HCP-1 / 60nm 102.7％ 102.1％ Device Example 3 Compound B06 / 20nm HCP-1 / 60nm 105.5％ 108.3％ Device Example 4 Compound B17 / 20nm HCP-1 / 60nm 109.1％ 112.1％ Device Example 5 Compound B33 / 20nm HCP-1 / 60nm 107.4％ 110.4％ Device Example 6 Compound B50 / 20nm HCP-1 / 60nm 106.9％ 105.9％ Device Example 7 Compound B54 / 20nm HCP-1 / 60nm 104.5％ 106.2％ Device Example 8 Compound B57 / 20nm HCP-1 / 60nm 107.1％ 105.6％ Device Example 9 Compound B62 / 20nm HCP-1 / 60nm 110.4％ 107.1％ Device Example 10 Compound B69 / 20nm HCP-1 / 60nm 105.3％ 111.4％ Device Example 11 Compound B72 / 20nm HCP-1 / 60nm 107.8％ 112.5％ Device Example 12 Compound B80 / 20nm HCP-1 / 60nm 105.8％ 116.3％ Device Example 13 Compound B89 / 20nm HCP-1 / 60nm 106.2％ 117.5％ Device Example 14 Compound B97 / 20nm HCP-1 / 60nm 105.3％ 114.3％ Device Example 15 Compound B100 / 20nm HCP-1 / 60nm 102.9％ 109.6％ Device Example 16 Compound B134 / 20nm HCP-1 / 60nm 110.2％ 116.3％ Device Example 17 Compound C03 / 20nm HCP-1 / 60nm 106.5％ 115.9％ Device Example 18 Compound C12 / 20nm HCP-1 / 60nm 103.4％ 120.4％ Device Example 19 Compound C25 / 20nm HCP-1 / 60nm 108.2％ 112.9％ Device Example 20 Compound D01 / 20nm HCP-1 / 60nm 104.1％ 98.6％ Device Example 21 Compound D05 / 20nm HCP-1 / 60nm 101.2％ 101.9％ Device Example 22 Compound D23 / 20nm HCP-1 / 60nm 98.5％ 107.3％ Device Example 23 Compound D31 / 20nm HCP-1 / 60nm 102.4％ 112.8％ Device Example 24 Compound D32 / 20nm HCP-1 / 60nm 99.1％ 119.4％ Device Example 25 Compound E12 / 20nm HCP-1 / 60nm 99.4％ 108.5％ Device Comparative Example 1 / HCP-1 / 80nm 85.6％ 91.5％ Device Comparative Example 2 Compound A09 / 80nm / 63.5％ 85.4％ Device Comparative Example 3 Comparative Compound 1 / 20nm HCP-1 / 60nm 93.80％ 90.6％ Device Comparative Example 4 Comparative Compound 2 / 20 nm HCP-1 / 60 nm 100.0％ 100.0％ Device Comparative Example 5 Comparative Compound 3 / 20 nm HCP-1 / 60 nm 100.5％ 102.4％ Device Comparative Example 6 Comparative Compound 4 / 20 nm HCP-1 / 60 nm 101.6％ 105.Z％ Device Comparative Example 7 Comparative Compound 5 / 20 nm HCP-1 / 60 nm 98.10％ 97.1％ Device Comparative Example 8 Comparative Compound 6 / 20 nm HCP-1 / 60 nm 96.90％ 95.4％ Device Comparative Example 9 Comparative Compound 7 / 20 nm HCP-1 / 60 nm 95.40％ 93.6％

[0191] Note: Index is obtained by dividing the current efficiency (cd / A) by CIEy, which is a widely 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.

[0192] The data in Table 5 show that compared with Device Comparative Example 1 having only a high refractive index light extraction layer, the device performance (Index) of the device using the composite light extraction layer with the compound of the present invention as the low refractive index first light extraction layer and the high refractive index second light extraction layer is improved by more than 15%, and the lifetime is improved by more than 10%.

[0193] Compared with Device Comparative Example 2 having only a low refractive index light extraction layer, the device performance (Index) of the device using the composite light extraction layer with the compound of the present invention as the low refractive index first light extraction layer and the high refractive index second light extraction layer is improved by more than 40%, and the lifetime is improved by more than 15%.

[0194] Compared with Device Comparative Examples 3 to 9, compared with Comparative Compounds 1 to 7, the device performance (Index) of the compounds of the present invention has increased by 5% to 10%, and the device lifetime has increased by 5% to 10%. It shows that by introducing a new core group, the refractive index of the compound can be effectively reduced, and the thermal stability and glass transition temperature of the compound can be improved, thereby effectively improving the device efficiency and lifetime.

[0195] In summary, when the compound of the present invention is used as the first light extraction layer material and combined with a second light extraction layer with a high refractive index to prepare a composite light extraction layer for application in an OLED device, the device efficiency can be effectively improved. At the same time, by changing the core group of the compound, the refractive index of the compound can be effectively reduced, and the thermal stability and glass transition temperature of the compound can be improved, thereby effectively improving the device efficiency and lifetime.

[0196] In conclusion, 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 in 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, which are the same or different, 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; n independently represents 0, 1, or 2; p independently represents 1, 2, 3, 4, or 5; m independently represents 0, 1, 2, 3, 4, or 5; When n represents 0, at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3); 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, characterized in that The organic compound has a structure represented by the general formulas (2-1) to (2-2): In the general formulas (2-1) and (2-2), 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, which are the same or different, 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; In the general formula (2-1), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3); In the general formula (2-2), n independently represents 1 or 2; p independently represents 1, 2, 3, 4, or 5; m 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.

3. The organic compound according to claim 1 or 2, characterized in that: R1 and R2 independently represent a fluorine atom or a trifluoromethyl group; R5 independently represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

4. 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, which are the same or different, 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; In the general formulas (3-1) to (3-3), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented as C-CF3); In the general formulas (3-4) to (3-6), n independently represents 1 or 2; p independently represents 1, 2, 3, 4, or 5; m 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.

5. The organic compound according to claim 1 or 2, wherein the compound has a structure represented by General Formula (4-1) to General Formula (4-10): In General Formula (4-1) to General Formula (4-10) 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; In General Formula (4-1) to General Formula (4-5), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented by C-CF3); In General Formula (4-6) to General Formula (4-10), n independently represents 1 or 2; p independently represents 1, 2, 3, 4 or 5; m independently represents 0, 1, 2, 3, 4 or 5.

6. The organic compound according to claim 1 or 2, wherein the compound has a structure represented by General Formula (5-1) to General Formula (5-3): In General Formula (5-1) to General Formula (5-3) 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; In General Formula (5-1), at least one of X represents a carbon atom substituted with a trifluoromethyl group (which can be represented by C-CF3); p independently represents 1, 2, 3, 4 or 5; m independently represents 0, 1, 2, 3, 4 or 5.

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

8. An organic electroluminescent device, which comprises: A substrate layer; A first electrode, which is on the substrate layer; An organic functional layer, which is on the first electrode; A second electrode, which is on the organic functional layer; And a light extraction layer on the second electrode; Characterized in that the light extraction layer contains one or more of the organic compounds described in any one of claims 1-7.

9. The organic electroluminescent device according to claim 8: The light extraction layer includes a first light extraction layer and a second light extraction layer. The first light extraction layer is on the second electrode; the second light extraction layer is on 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 1-7.

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