Host material, organic electroluminescent material containing double host and application

Abstract

The application belongs to the field of organic electroluminescent materials, and provides a host material, an organic electroluminescent material containing double hosts and application. The organic electroluminescent material containing double hosts comprises a first host material and a second host material, wherein the first host material is the host material, and the specific structure is shown in the specification. The organic electroluminescent material containing double hosts is applied to a specific light-emitting device, and has low driving voltage, high luminous efficiency and long service life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic electroluminescent materials, and particularly relates to a host material, an organic electroluminescent material containing a double host and an organic electroluminescent device. BACKGROUND

[0002] Organic Light Emitting Diode (OLED) technology is a type of electroluminescent technology that uses organic materials as the light-emitting layer. This technology has the advantages of low driving voltage, high brightness, high efficiency, and the ability to achieve large-area flat panel color display. The principle of organic electroluminescence is based on the injection of electrons and holes from the cathode and anode into the organic layer when a voltage is applied to the organic material. The electrons and holes recombine in the light-emitting layer to form excitons, which release energy during relaxation and produce photons, thereby achieving light emission. In recent years, significant progress has been made in the study of organic electroluminescent technology, including improving the efficiency, lifetime and brightness of devices, reducing costs and achieving a wider color gamut. These advances have made organic electroluminescent technology a promising technology for display and lighting applications.

[0003] Organic Light Emitting Diode (OLED) efficiency generally refers to the ability of a device to convert electrical energy into light energy, and is mainly divided into internal quantum efficiency and external quantum efficiency. Internal quantum efficiency refers to the efficiency of light emission from the recombination of excitons in the light-emitting layer, while external quantum efficiency refers to the ratio of the number of photons extracted from the device to the number of electrons injected into the device.

[0004] The current technical problems of organic electroluminescent devices mainly include the following aspects:

[0005] (1) Efficiency problem: the light-emitting efficiency of organic electroluminescent devices is relatively low and needs to be further improved. (2) Lifetime problem: the stability and durability of organic materials are poor, resulting in a short device lifetime. (3) Color stability problem: the color of organic materials is easily affected by environmental factors such as temperature and humidity, resulting in unstable color. (4) Manufacturing process problem: the manufacturing process of organic electroluminescent devices is relatively complex and needs to be further optimized. (5) Cost problem: the cost of organic materials and manufacturing processes is high, limiting the large-scale application of organic electroluminescent devices.

[0006] The efficiency of OLED is improved by the host-guest doping in the light-emitting layer, because the radiation transition of the triplet exciton of most organic molecules is forbidden, and the contribution to electroluminescence is small. By doping platinum, iridium, osmium and other organic metal complexes, the triplet exciton of the organic molecule can be transferred to the triplet state of the metal complex, thereby greatly improving the efficiency of the organic light-emitting device. However, the triplet-triplet annihilation (TTA) occurs in the transfer process of the triplet exciton, thereby causing energy loss and resulting in efficiency roll-off of the organic light-emitting device.

[0007] Therefore, how to develop a long-life, low driving voltage organic electroluminescent material containing double hosts, a preparation method and an organic electroluminescent device are technical problems that need to be solved by those skilled in the art. SUMMARY

[0008] Therefore, in view of the deficiencies of the prior art, the application provides a host material, an organic electroluminescent material containing double hosts and applications. The organic electroluminescent material containing double hosts is applied to a specific light-emitting device, and has low driving voltage, high luminous efficiency and long service life.

[0009] It should be noted that the organic electroluminescent device containing double hosts provided by the application can disperse the triplet exciton on two hosts by using the double host material, can reduce triplet-triplet annihilation (TTA), and can reduce the driving voltage of the organic electroluminescent device while improving the efficiency and service life of the device.

[0010] The triazine structure has strong electron accepting ability and can effectively transport electrons. The triazine structure can reduce the energy required for electron injection, so that the organic electroluminescent device can be driven at a lower voltage, thereby reducing the energy consumption of the device and prolonging the service life of the device. The triazine structure usually has high thermal stability and chemical stability, which can make the organic electroluminescent device maintain good performance stability in different working environments and reduce the performance degradation of the device caused by environmental factors. By chemically modifying the triazine structure or combining it with other functional groups, the light-emitting color of the organic electroluminescent device can be adjusted to a certain extent, and the light-emitting spectrum of the device can be finely controlled to meet the color display requirements of different application scenarios. The hole injection and transport ability of the carbazole compound is high, and by changing the bonding style of the carbazole ring and the type / number of substituents of the skeleton, the hole injection and transport ability can be controlled at a high level.

[0011] In order to achieve the above-mentioned purposes, the following technical solutions are adopted:

[0012] The first technical purpose of the application is to provide a host material, and the structure of the host material is shown in general formula one:

[0013] ;

[0014] wherein,

[0015] L1, L2, L3 are a bond, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (C3-C20)heteroaryl, the heteroatoms of which are selected from oxygen, nitrogen, sulfur and the like;

[0016] R1, R2, R3 are each independently selected from hydrogen, a substituted or unsubstituted C1-C10 alkyl, a substituted or unsubstituted phosphine oxide, a substituted or unsubstituted silyl, a substituted or unsubstituted C6-C42 aryl, a substituted or unsubstituted C3-C42 heteroaryl, the heteroatoms of which are selected from oxygen, nitrogen, sulfur and the like;

[0017] A is selected from benzene, naphthalene, anthracene, phenanthrene, dibenzofuran, dibenzothiophene, fluorene, indole or carbazole.

[0018] Further,

[0019] L1, L2 are a bond, a substituted or unsubstituted C6-C18 aryl, a substituted or unsubstituted C3-C12 heteroaryl, L3 is a bond, a substituted or unsubstituted C6-C12 aryl, a substituted or unsubstituted C3-C12 heteroaryl, the heteroatoms of which are selected from oxygen, nitrogen, sulfur and the like;

[0020] R1, R2 are each independently selected from a substituted or unsubstituted phosphine oxide, a substituted or unsubstituted silyl, a substituted or unsubstituted C6-C30 aryl, a substituted or unsubstituted C3-C30 heteroaryl, the heteroatoms of which are selected from oxygen, nitrogen, sulfur and the like; R3 is selected from hydrogen, a substituted or unsubstituted C6-C24 aryl, a substituted or unsubstituted C3-C24 heteroaryl, the heteroatoms of which are selected from oxygen, nitrogen, sulfur and the like.

[0021] Still further, R1, R2 are each independently selected from one or a combination of two or more of the following structures: .

[0022] In the above technical solution, "substituted or unsubstituted" means that the group can be unsubstituted or substituted with one or more substituents, "substituted" means that the hydrogen atom bonded to the carbon atom of the compound is changed into another substituent, and the position of substitution is not limited as long as it is the position of hydrogen atom to be substituted, i.e. the position that the substituent can substitute, and when two or more substituents are substituted, the two or more substituents can be the same or different from each other.

[0023] and the substituent group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, deuterium-substituted C3-C20 cycloalkyl, deuterium-substituted C3-C20 heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen, sulfur, etc.

[0024] In the technical solution of the present application, the general formula one has the following structure, but is not limited to the following structure: .

[0025] A second technical object of the present application is to provide a double-host-containing organic electroluminescent material, which comprises a first host material and a second host material, the first host material is the above-mentioned host material, and the second host material has the structure shown in general formula two:

[0026] ;

[0027] wherein,

[0028] Ar is selected from hydrogen, substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom thereof is selected from oxygen, nitrogen, sulfur, etc.;

[0029] L4 is selected from a connecting bond, substituted or unsubstituted C1-10 alkyl, substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom thereof is selected from oxygen, nitrogen, sulfur, etc.;

[0030] T1 and T2 are each independently selected from substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom thereof is selected from oxygen, nitrogen, sulfur, etc.

[0031] A1and A2are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted C1-10alkyl group, a substituted or unsubstituted phosphineoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted C6-C42aryl group, a substituted or unsubstituted C3-C42heteroaryl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like.

[0032] Further,

[0033] Ar is selected from the group consisting of hydrogen, a substituted or unsubstituted C6-C24aryl group, a substituted or unsubstituted C3-C24heteroaryl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like;

[0034] L4is selected from the group consisting of a bond, a substituted or unsubstituted C6-C18aryl group, a substituted or unsubstituted C3-C18heteroaryl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like;

[0035] T1and T2are each independently selected from the group consisting of a substituted or unsubstituted C6-C18aryl group, a substituted or unsubstituted C3-C18heteroaryl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like;

[0036] A1and A2are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted C1-10alkyl group, a substituted or unsubstituted phosphineoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted C6-C24aryl group, a substituted or unsubstituted C3-C24heteroaryl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like.

[0037] The "substituted or unsubstituted" described above means that the group can be unsubstituted, or substituted with one or more substituents, and the "substitution" means that a hydrogen atom bonded to a carbon atom of the compound is changed to another substituent, and the position of substitution is not limited as long as it is a position where a hydrogen atom is substituted, i.e., a position where a substituent can be substituted, and when two or more substituents are substituted, the two or more substituents can be the same as or different from each other;

[0038] and, the group substituted in the "substituted or unsubstituted" is selected from the group consisting of deuterium, fluorine, a C1-C10alkyl group, a deuterium-substituted C1-C10alkyl group, a C3-C20cycloalkyl group, a C3-C20heterocycloalkyl group, a deuterium-substituted C3-C20cycloalkyl group, a deuterium-substituted C3-C20heterocycloalkyl group whose hetero atom is selected from the group consisting of oxygen, nitrogen, sulfur and the like.

[0039] and, the hydrogen atoms in the group can all be unsubstituted, all be substituted with deuterium, or partially be substituted with deuterium.

[0040] The group substituted in the above "substituted or unsubstituted" is the same as in the first technical object of the present application, and will not be listed one by one.

[0041] According to one embodiment of the present application, the second host material has the following structure, but is not limited to the following structure: .

[0042] A third technical object of the present application is to provide a preparation method of the above-mentioned double-host-containing organic electroluminescent material, and the synthetic route is as follows:

[0043] 1. Preparation of general formula one: ;

[0044] (1) Under a nitrogen protection system, take reaction substance 1 (1 eq), reaction substance 2 (1 eq), potassium carbonate (2-3 eq) and put them into a reaction system, add tetrahydrofuran, water and catalyst tetra (triphenylphosphine) palladium (0.01-0.05 eq), react at 40°C for 24h under nitrogen protection, after the reaction is completed, cool to 25°C, and after treatment, the compound H-T-1 shown is obtained;

[0045] (2) Under a nitrogen protection system, take reaction substance 3 (1 eq), reaction substance 4 (1 eq), potassium carbonate (2-3 eq) and put them into a reaction system, add toluene, ethanol, water and catalyst tetra (triphenylphosphine) palladium (0.01-0.05 eq), reflux at 90°C for 24h under nitrogen protection, after the reaction is completed, cool to 25°C, and after treatment, the compound H-T-2 shown is obtained;

[0046] (3) Under a nitrogen protection system, take H-T-1 (1 eq), H-T-2 (1 eq), sodium tert-butoxide (2-3 eq) and put them into a reaction system, add dry toluene, catalyst tris (dibenzylideneacetone) palladium (0.02-0.04 eq) and 50% tri-tert-butyl phosphine (0.04-0.08 eq), reflux at 120°C for 24h under nitrogen protection, after the reaction is completed, cool to 25°C, and after treatment, the compound H-T-3 shown is obtained;

[0047] (4) Under a nitrogen protection system, take H-T-3 (1 eq), pinacol diboron (2 eq), potassium acetate (1.5-3.5 eq) and put them into a reaction system, add dioxane, catalyst tris (dibenzylideneacetone) palladium (0.02-0.06 eq) and X-phos (0.04-0.12 eq), reflux at 100°C for 24h under nitrogen protection, after the reaction is completed, cool to 25°C, and after treatment, the compound H-T-4 shown is obtained;

[0048] (5) Under the nitrogen protection system, take out the reactant 5 (1 eq), the reactant 6 (1 eq), potassium carbonate (2~3 eq) and put them into the reaction system, add toluene, ethanol, water and the catalyst tetrakis (triphenylphosphine) palladium (0.01~0.05 eq), under the nitrogen protection, react at 40 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated compound H-T-5 is obtained;

[0049] (6) Under the nitrogen protection system, take out H-T-5 (1 eq), the reactant 7 (1 eq), potassium carbonate (2~3 eq) and put them into the reaction system, add toluene, ethanol, water and the catalyst tetrakis (triphenylphosphine) palladium (0.01~0.05 eq), under the nitrogen protection, react at 60 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated compound H-T-6 is obtained;

[0050] (7) Under the nitrogen protection system, take out H-T-4 (1 eq), H-T-6 (1 eq), potassium carbonate (2~3 eq) and put them into the reaction system, add tetrahydrofuran, water and the catalyst tetrakis (triphenylphosphine) palladium (0.01~0.05 eq), under the nitrogen protection, reflux at 90 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated general formula one is obtained.

[0051] 2, Preparation of the general formula two: ;

[0052] (1) Under the nitrogen protection system, take out the reactant 1 (1 eq), the reactant 2 (1 eq), potassium carbonate (2~3 eq) and put them into the reaction system, add toluene, ethanol, water and the catalyst tetrakis (triphenylphosphine) palladium (0.01~0.05 eq), under the nitrogen protection, reflux at 90 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated compound G-T-1 is obtained;

[0053] (2) Under the nitrogen protection system, take out G-T-1 (1 eq), the reactant 3 (1 eq), potassium carbonate (2~3 eq) and put them into the reaction system, add toluene, ethanol, water and the catalyst tetrakis (triphenylphosphine) palladium (0.01~0.05 eq), under the nitrogen protection, reflux at 90 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated compound G-T-2 is obtained;

[0054] (3) Under the nitrogen protection system, take out G-T-2 (1 eq), the reactant 4 (1 eq), sodium tert-butoxide (2~3 eq) and put them into the reaction system, add dry toluene, the catalyst tris (dibenzylideneacetone) dipalladium (0.02~0.04 eq) and 50% tri-tert-butyl phosphine (0.04~0.08 eq), under the nitrogen protection, reflux at 120 ℃ for 24 h, after the reaction is completed, cool to 25 ℃, and after treatment, the indicated general formula two is obtained.

[0055] A fourth technical object of the present application is to provide a use of the double-host-containing organic electroluminescent material in the preparation of an organic electroluminescent device.

[0056] In particular, the organic electroluminescent device comprises a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; and the organic electroluminescent material layer comprises a light-emitting layer; the light-emitting layer comprises a dopant material and the double-host-containing organic electroluminescent material as described above.

[0057] In particular, the organic electroluminescent device comprises a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; and the organic electroluminescent material layer comprises a light-emitting layer; the light-emitting layer comprises a dopant material and the double-host-containing organic electroluminescent material as described above.

[0058] More specifically, the organic electroluminescent device comprises an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode. The light-emitting layer comprises the first host material represented by Formula I and the second host material represented by Formula II.

[0059] As an anode material, a material having a large work function is generally preferred to enable a smooth injection of holes into the organic material layer. The anode material that can be used for the first electrode of the organic electroluminescent device of the present application includes a metal such as vanadium, chromium, copper, zinc, and gold, or an alloy thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); a combination of a metal and an oxide such as ZnO:Al or SnO2:Sb; a conductive polymer such as poly(3-methylthiophene), poly[3,4-(ethylen-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but is not limited thereto.

[0060] As a cathode material, a material having a small work function is generally preferred to enable a smooth injection of electrons into the organic material layer. The cathode material that can be used for the second electrode of the organic electroluminescent device of the present application includes a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof; a multi-layered structure material such as LiF / Al or LiO2 / Al, etc., but is not limited thereto.

[0061] A hole injection layer material is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. The hole injection material includes metal porphyrin, oligothiophene, arylamine-based organic material, hexacyno-hexaazatriphenylene-based organic material, quinacridone-based organic material, perylene-based organic material, anthraquinone, and polyaniline-based and polythiophene-based conductive polymers, etc.

[0062] The hole transport layer material is a material capable of receiving holes from the anode or hole injection layer and transporting the holes to the light emitting layer, and having a high hole mobility, and includes an arylamine-based organic material, a conductive polymer, a block copolymer having a conjugated portion and a non-conjugated portion, etc., but is not limited thereto.

[0063] An electron blocking layer can be disposed between the hole transport layer and the light emitting layer. As the electron blocking layer, a material known in the art, for example, an arylamine-based organic material, can be used.

[0064] The host material of the light emitting layer is selected from the structure of the present application.

[0065] A hole blocking layer can be disposed between the electron transport layer and the light emitting layer, and a material known in the art, for example, a triazine-based compound, can be used.

[0066] The electron transport layer can function to facilitate electron transport, and the electron transport material is a material advantageously receiving electrons from the cathode and transporting the electrons to the light emitting layer, having a high electron mobility. This includes an 8-hydroxyquinoline-Al complex, a complex containing Alq3, an organic radical compound, a hydroxyflavone-metal complex, etc., but is not limited thereto. The thickness of the electron transport layer can be 1 nm to 50 nm, and the electron transport layer having a thickness of 1 nm or more has an advantage of preventing a decrease in electron transport characteristics, and the thickness of 50 nm or less has an advantage of preventing an increase in driving voltage caused by the electron transport layer being too thick.

[0067] The electron injection layer can function to facilitate electron injection, and the electron injection material preferably has the ability to transport electrons, has an effect of injecting electrons from the cathode, has an excellent electron injection effect on the light emitting layer or light emitting material, prevents excitons generated in the light emitting layer from migrating to the hole injection layer, and in addition thereto, has an excellent thin film forming ability. Specific examples thereof include fluorenone, anthraquinone dimethane, diphenylquinone, thiopyran dioxide, oxazole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthrone, and derivatives thereof, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but are not limited thereto.

[0068] The organic electroluminescent device described above can be a top emission type, a bottom emission type, or a dual side emission type, depending on the material used.

[0069] In addition, the organic electroluminescent device described in the present application can be used in an organic solar cell, electronic paper, an organic photoreceptor, or an organic thin film transistor.

[0070] According to the technical solution described above, compared with the prior art, the present application has the following beneficial effects:

[0071] 1) The organic electroluminescent material provided by the present application is a double-host organic compound. It contains triphenylphosphine oxide group, which has the following advantages:

[0072] 1. Improved electron mobility: Triphenylphosphine oxide has relatively strong electron-withdrawing ability and special conjugated structure, which can effectively improve the electron mobility.

[0073] 2. Improved triplet energy level: It helps to improve the triplet energy level of the compound, which can significantly improve the device efficiency and reduce the efficiency roll-off in green light emitting devices.

[0074] 3. Improved photoelectric performance: Phosphorus atom can change the electronic structure of the material through σ-π interaction between its d orbit and π conjugated system, and it also has good modifiability, such as oxidation, sulfuration or coordination with metal, etc., so as to effectively regulate the photoelectric performance of the material.

[0075] 2) The triazine structure has the following advantages:

[0076] 1. Improved stability and electron resistance: The triazine structure makes the compound have good stability and electron resistance, which ensures the stability of the material in the working environment and reduces the performance degradation caused by external factors and electron impact.

[0077] 2. Enhanced electron injection and transport ability: This structure has strong electron-withdrawing property, which can reduce the electron injection energy barrier, make it easier for electrons to inject into organic materials, and improve the electron migration speed and transport efficiency.

[0078] 3. Reduced driving voltage: The triazine structure material applied in organic electroluminescent devices can significantly reduce the driving voltage of the device, reduce energy consumption and improve energy utilization efficiency.

[0079] 4. Improved light emitting performance: Triazine compounds have good light emitting performance and can be used to prepare organic electroluminescent devices, which can improve the current efficiency of the device and enable the device to emit light with higher brightness at lower current.

[0080] 5. Prolonged device life: The material based on triazine structure can improve the stability and efficiency of the device, reduce the damage and aging of the device during operation, and effectively prolong the service life of the device.

[0081] 6. Improved thermal stability: The compound with triazine structure as the core and side chains formed by aryl groups has good thermal stability, which can ensure the stable operation of the device at different temperature environments.

[0082] 7. Improved film forming property: Some triazine compounds are designed to improve the planarity of the molecule, enhance the film forming property of the material, reduce the problems in the production process, and facilitate large-scale production and preparation of high-quality thin film devices.

[0083] 3) The carbazole structure has the following advantages:

[0084] 1. Improved stability and glass transition temperature: carbazole has a large π-conjugated rigid planar structure, introducing carbazole groups into the molecular structure can improve the stability and glass transition temperature of the compound, ensuring the stability of the material in different environments.

[0085] 2. Enhanced hole transport ability: carbazole molecules have excellent electron-donating ability, and their derivatives have good hole transport properties, which can make hole transport more efficient, balance electron and hole transport rates, and improve light-emitting efficiency.

[0086] 3. Good light-emitting performance: carbazole compounds have strong absorption in the ultraviolet range.

[0087] 4. Easy to modify structure: carbazole molecules are easy to modify at positions 3, 6, and 9, and various substituents or functional groups can be introduced to obtain derivatives with larger π-electron conjugated systems, thereby adjusting the optical and electrical properties of the target product.

[0088] 5. Lower driving voltage: organic electroluminescent devices prepared with carbazole-containing compounds as light-emitting layer or electron-blocking layer materials have lower driving voltage, which can reduce energy consumption.

[0089] 6. Improved current efficiency: devices made of carbazole-containing compounds can also improve current efficiency, allowing the device to emit light at higher brightness with lower current.

[0090] 7. Prolong the service life of the device: carbazole-based materials can improve the stability and efficiency of the device, reduce damage and aging during operation, and prolong the service life of the device.

[0091] 8. Improved thermal stability: carbazole has a large planar rigidity, making carbazole-containing compounds have good thermal stability, ensuring stable operation of the device in different temperature environments.

[0092] 9. Improved carrier mobility: introducing multiple specific groups to the carbazole nucleus can effectively extend the conjugated system of the molecule, avoid carrier migration localization, and improve carrier mobility.

[0093] Based on the above analysis, the double-host structure in the present application can reduce the driving voltage of the organic electroluminescent device while improving the efficiency and service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0094] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only represent a part of the embodiments of the present application, and all other drawings obtained by those skilled in the art without creative effort based on the provided drawings also belong to the protection scope of the present application.

[0095] Figure 1 NMR spectrum of hydrogen of compound H061 of the present application. DETAILED DESCRIPTION

[0096] The technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments only represent a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort also belong to the protection scope of the present application.

[0097] The embodiments of the present application disclose a host material, an organic electroluminescent material containing double hosts and an organic electroluminescent device.

[0098] In addition, it should be noted that the numerical values given in the following embodiments are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, rather than an absolutely accurate number.

[0099] Example 1: Preparation of compound H061 .

[0100] (1) Under a nitrogen protection system, the reactant 1 (1 eq) (cas: 2377074-27-4), the reactant 2 (1 eq) (cas: 1191934-06-1) and potassium carbonate (2.5 eq) were weighed into a reaction system, nitrogen was replaced, tetrahydrofuran, water and catalyst tetra (triphenylphosphine) palladium (0.02 eq) were added, nitrogen was replaced, and the reaction was carried out at 40°C for 24h under nitrogen protection. After the raw material was reacted, heating was stopped, and the temperature was cooled to 25°C. Water was added for extraction and separation, the organic phase was collected, anhydrous magnesium sulfate was added for drying, and the crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography with dichloromethane / hexane as eluent to obtain H061-1.

[0101] HPLC: 97.56%; molecular weight: 434.03; yield: 68.32%.

[0102] (2) Under the nitrogen protection system, compound H061-1 (1 eq), reactant 3 (1 eq) (cas: 86-74-8), sodium tert-butoxide (2.5 eq) were weighed into the reaction system, replaced with nitrogen, dry toluene, catalyst tris(dibenzylideneacetone)dipalladium (0.02 eq) and 50% tri-tert-butyl phosphine (0.044 eq) were added, replaced with nitrogen, and refluxed at 120°C for 24h under the protection of nitrogen. After the raw material was reacted, the heating was stopped, cooled to 25°C, water was added for extraction and separation, the organic phase was collected, anhydrous magnesium sulfate was added for drying, and the crude product was obtained by rotary evaporation under reduced pressure; the crude product was purified by silica gel column chromatography with dichloromethane / hexane as the eluent to obtain H061-2;

[0103] HPLC: 98.76%; molecular weight: 521.25; yield: 62.77%.

[0104] (3) Under the nitrogen protection system, H061-2 (1 eq), pinacol diborane (2 eq), potassium acetate (2 eq) were weighed into the reaction system, replaced with nitrogen, dioxane, catalyst tris(dibenzylideneacetone)dipalladium (0.04 eq) and X-phos (0.08 eq) were added, replaced with nitrogen, and refluxed at 100°C for 24h under the protection of nitrogen. After the raw material was reacted, the heating was stopped, cooled to 25°C, water was added for extraction and separation, the organic phase was collected, anhydrous magnesium sulfate was added for drying, and the crude product was obtained by rotary evaporation under reduced pressure; the crude product was purified by silica gel column chromatography with dichloromethane / hexane as the eluent to obtain H061-3;

[0105] HPLC: 98.60%; molecular weight: 569.58; yield: 72.5%.

[0106] (4) Under the nitrogen protection system, compound H061-3 (1 eq), reactant 4 (1 eq) (cas: 1883265-32-4), potassium carbonate (2.5 eq) were weighed into the reaction system, replaced with nitrogen, tetrahydrofuran, water and catalyst tetrakis(triphenylphosphine)palladium (0.02 eq) were added, replaced with nitrogen, and refluxed at 90°C for 24h under the protection of nitrogen. After the raw material was reacted, the heating was stopped, cooled to 25°C, water was added for extraction and separation, the organic phase was collected, anhydrous magnesium sulfate was added for drying, and the crude product was obtained by rotary evaporation under reduced pressure; the crude product was purified by silica gel column chromatography with dichloromethane / hexane as the eluent to obtain H061;

[0107] HPLC: 99.85%; molecular weight: 764.48; yield: 64.59%.

[0108] The nuclear magnetic resonance hydrogen spectrum is as shown in Figure 1 .

[0109] Example 2: Preparation of compound G004 .

[0110] Under the condition of nitrogen, 9H, 9'H-3, 3'-biscarbazole (1 eq), bromobenzene (2 eq), sodium tert-butoxide (3 eq) were weighed into the reaction vessel in turn, and toluene was added as the reaction solvent. Then, catalyst Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.04 eq) were added under the protection of nitrogen. The mixture was refluxed at 120°C for 24 hours under the protection of nitrogen, and then cooled to 25°C. Pure water was added to the mixture, and the mixture was stirred for 30 minutes and then allowed to stand to separate into two layers. The mixture was separated by column chromatography to obtain the final product G004.

[0111] HPLC: 99.92%; molecular weight: 484.36; yield: 76.32%.

[0112] In addition, it should be noted that other compounds of the present application can be obtained by referring to the preparation methods of the above-mentioned examples, and therefore will not be exemplified one by one.

[0113] Device example: preparation of an organic electroluminescent device

[0114] ITO anode: ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was washed in distilled water for 2 times, ultrasonic washing for 30 min, and then washed in distilled water for 2 times, ultrasonic washing for 10 min. After washing, the substrate was ultrasonic washed in methanol, acetone and isopropanol in turn (5 min for each washing), dried, and then transferred to a plasma cleaning machine for washing for 5 min to obtain the ITO anode.

[0115] HIL (hole injection layer): 4,4 ’ ,4 ’’ -tris (N-3-methylphenyl-N-phenylamino) triphenylamine (m-MTDATA) 200 angstroms were vacuum evaporated on the ITO anode in an evaporator to form a hole injection layer.

[0116] HTL (hole transport layer): NPB (i.e. N, N'-diphenyl-N, N'-(1-naphthyl)-1, 1'-biphenyl-4, 4'-diamine) 400 angstroms were vacuum evaporated on the hole injection layer to form a hole transport layer.

[0117] Light-emitting layer: The light-emitting layer comprises a first host material, a second host material and a guest dopant. After the formation of the hole injection layer and the hole transport layer, the light-emitting layer is formed on the HTL: the first host compound and the second host compound are introduced into two small chambers of a vacuum vapor deposition device as hosts, and the compound Z1 is introduced into another small chamber as a dopant; the two host materials are evaporated at a rate of 1:1, and the dopant material is evaporated at a different rate at the same time to deposit at a doping amount of 3wt% based on the total amount of the host and the dopant to form a light-emitting layer with a thickness of 40 nm on the hole transport layer.

[0118] HBL (hole blocking layer): 100Åm of bis(2-methyl-8-hydroxyquinoline-N1, O8)-(1,1'-biphenyl-4-hydroxy) aluminum (BAlq) is vacuum evaporated on the light-emitting layer to form a hole blocking layer.

[0119] ETL (electron transport layer): 400Å of aluminum 8-hydroxyquinoline (Alq3) is vacuum evaporated on the hole blocking layer to form an electron transport layer.

[0120] EIL (electron injection layer): 210Å of LiF is vacuum evaporated on the electron transport layer to form an electron injection layer.

[0121] Cathode: magnesium and silver are evaporated at a rate ratio of 1:9 to form a cathode, i.e. an organic electroluminescent device is obtained.

[0122] The preparation method of the organic electroluminescent device provided in the above device example is used to replace the first host compound and the second host compound with another 50 organic electroluminescent compounds to evaporate the host material, and the organic electroluminescent device of the corresponding compound is prepared.

[0123] Green light dopant material (Z1) .

[0124] Device examples 1-25, comparative examples 1-5 and parallel examples 1-4:

[0125] The device manufacturing processes of device examples 1-25, comparative examples 1-5 and parallel examples 1-4 are completely the same, and the same substrate material and electrode material are used, and the film thickness of the electrode material is also consistent. The difference is that the two host materials are not the same, and the corresponding first host compound and second host compound in Table 1 are selected respectively, and the specific parameters are shown in Table 1.

[0126] Table 1 is the parameters used in device examples 1-25, comparative examples 1-5 and parallel examples 1-4.

[0127] Table 1

[0128]

[0129] The comparative example structures are as follows:

[0130] Performance detection: the driving voltage, luminous efficiency and lifetime of the organic electroluminescent devices obtained from the above comparative examples 1-5, parallel examples 1-4 and device examples 1-25 were characterized at a brightness of 18000 (nits), and the test results are as shown in Table 2.

[0131] Table 2

[0132]

[0133] As can be seen from Table 2, the driving voltage of the organic electroluminescent device provided by device example 1-25 and parallel example 1-4 is 3.21V-3.85V, which is significantly smaller than the driving voltage of comparative example 1-5, and the luminous efficiency is higher than that of comparative example 1-5, and the lifetime is significantly improved compared with comparative example 1-5.

[0134] Therefore, the organic electroluminescent device prepared by using the organic electroluminescent compound provided by the present application as the light-emitting layer material has a significantly reduced driving voltage and significantly improved luminous efficiency and lifetime compared with the organic electroluminescent device prepared by using comparative compounds E-1, E-2 and F-1 as the double host material of the light-emitting layer.

[0135] This is because the triazine structure has good stability, which can increase the device lifetime, and the triazine structure has strong electron accepting ability, which can reduce the energy required for electron injection, thereby reducing the voltage required for device operation; the hole injection and transport energy of the carbazole compound is high, and by changing the bonding style of the carbazole ring and the type / number of substituents on the skeleton, the hole injection and transport property can be controlled at a high level.

[0136] Therefore, by using the compound formed by mixing the first host compound and the second host compound to form the double host material, the injection amount of two charges into the organic layer can be adjusted to the preferred range, thereby achieving better element properties. And applying the double host material compound to the light-emitting layer material of the organic electroluminescent device can not only reduce the driving voltage, but also improve the luminous efficiency of the organic electroluminescent device and prolong the service life of the device.

[0137] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A host material characterized in that, The host material has a structure as shown in Formula I: ； wherein, L1, L2 are a connecting bond, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C3-C12 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur, and L3 is a connecting bond, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C3-C12 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur; R1, R2 are each independently selected from substituted or unsubstituted phosphine oxide, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur, and R3 is selected from hydrogen, substituted or unsubstituted C6-C24 aryl, and substituted or unsubstituted C3-C24 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur; A is selected from benzene, naphthalene; The substituted group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, deuterium-substituted C3-C20 cycloalkyl, and deuterium-substituted C3-C20 heterocycloalkyl, and the heteroatom is selected from oxygen, nitrogen, and sulfur.

2. A host material characterized by, The host material has a structure as shown in Formula I: ； wherein, L1, L2 are a connecting bond, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C3-C12 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur, and L3 is a connecting bond, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C3-C12 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, sulfur; A is selected from benzene, naphthalene; The substituted group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, deuterium-substituted C3-C20 cycloalkyl, and deuterium-substituted C3-C20 heterocycloalkyl, and the heteroatom is selected from oxygen, nitrogen, and sulfur. R1, R2 are each independently selected from one of the following structures: 。 3. A host material characterized by, The host material has the following structure: 。 4. An organic electroluminescent material containing a double host, characterized by The organic electroluminescent material containing a double host includes a first host material and a second host material, the first host material is the host material as claimed in claim 1, and the second host material has a structure as shown in Formula II: ； wherein, Ar is selected from hydrogen, substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom is selected from nitrogen; L4 is selected from a connecting bond, substituted or unsubstituted C1-10 alkyl, substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom is selected from nitrogen; T1 and T2 are each independently selected from substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom is selected from oxygen, nitrogen, and sulfur; A1 and A2 are each independently selected from hydrogen, substituted or unsubstituted C1-10 alkyl, substituted or unsubstituted phosphine oxide, substituted or unsubstituted C6-C42 aryl, and substituted or unsubstituted C3-C42 heteroaryl, and the heteroatom is selected from nitrogen; The substituent group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, deuterium-substituted C3-C20 cycloalkyl, deuterium-substituted C3-C20 heterocycloalkyl, and a heteroatom selected from oxygen, nitrogen, and sulfur.

5. The double-host-containing organic electroluminescent material according to claim 4, wherein Ar is selected from hydrogen, substituted or unsubstituted C6-C24 aryl, and substituted or unsubstituted C3-C24 heteroaryl having a heteroatom selected from nitrogen; L4 is selected from a bond, substituted or unsubstituted C6-C18 aryl, and substituted or unsubstituted C3-C18 heteroaryl having a heteroatom selected from nitrogen; T1 and T2 are each independently selected from substituted or unsubstituted C6-C18 aryl and substituted or unsubstituted C3-C18 heteroaryl having a heteroatom selected from oxygen, nitrogen, and sulfur; A1 and A2 are each independently selected from hydrogen, substituted or unsubstituted C1-10 alkyl, substituted or unsubstituted phosphorus oxy radical, substituted or unsubstituted C6-C24 aryl, and substituted or unsubstituted C3-C24 heteroaryl having a heteroatom selected from nitrogen.

6. A double-host-containing organic electroluminescent material, characterized by comprising: The double-host-containing organic electroluminescent material comprises a first host material and a second host material, the first host material is the host material as claimed in claim 1, and the second host material is selected from any one of the following structures: 。 7. An organic electroluminescent device, characterized by comprising The organic electroluminescent device comprises the host material as claimed in any one of claim 1, claim 2, and claim 3, or the double-host-containing organic electroluminescent material as claimed in any one of claim 4 and claim 6.

Images