A host compound, an organic electroluminescent material containing a double host, and an organic electroluminescent device

Abstract

This invention discloses a host compound, an organic electroluminescent material containing two hosts, and an organic electroluminescent device, relating to the field of organic electroluminescent materials technology. The host compound has a chemical structure as shown in Formula 1. The host compound of this invention contains benzo[a]cyclohexane-9-siliconfluorene, whose unique electronic structure brings excellent electrical and optical properties: σ-π conjugation effect: the silicon atom in the siliconfluorene core has two out-of-ring σ orbitals that can undergo σ-π conjugation with adjacent π orbitals. This effect can effectively reduce the lowest unoccupied orbital (LUMO) energy level of the molecule, significantly enhancing the electron affinity and electron injection / transport capabilities of the material.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and more specifically to a host compound, an organic electroluminescent material containing two hosts, and an organic electroluminescent device. Background Technology

[0002] Organic Light Emitting Diode (OLED) technology is a revolutionary breakthrough in modern display and lighting technology. It uses organic materials as the light-emitting layer, and its core lies in utilizing thin films of organic materials with semiconductor properties to directly convert electrical energy into light energy under an electric field. The history of this technology can be traced back to laboratory discoveries in the 1960s, but the real turning point was the invention of a low-voltage, high-efficiency double-layer device structure by Dr. Ching W. Tang's team at Kodak in 1987, laying the foundation for industrialization.

[0003] The research background of organic electroluminescent materials (OLED) can be summarized in the following four points:

[0004] 1. Technological Development Needs: OLEDs, with their flexibility, thinness, low power consumption, and high brightness, have been widely used in smartphones, televisions, wearable devices, and other fields. However, efficient, stable, and mass-producible materials remain a technological bottleneck, requiring optimization of material performance through molecular design.

[0005] 2. Material Performance Challenges: Traditional OLED materials (such as aromatic compounds) suffer from low luminous efficiency and short lifetime. Organic materials containing metal complexes (such as iridium ions) have become a research hotspot due to their high quantum yield, long lifetime, and excellent optical properties, but the challenges of processing and stability need to be addressed.

[0006] 3. Molecular design strategies: By controlling the photoelectric structure of π-conjugated systems (such as energy level differences and conjugation lengths) and introducing electron / hole transport enhancement groups (such as pyrrolidine aldehydes and benzotriazines), luminescence efficiency and stability can be significantly improved. Nitrogen-containing five-membered heterocyclic iridium complexes, due to their unique electronic properties, have become key materials for improving performance.

[0007] 4. Expanding Application Areas: In addition to displays and lighting, OLEDs also have potential in fields such as biosensing and photochemical reactions. Researching new materials will help promote their application in more scenarios and meet the demand for efficient and environmentally friendly materials.

[0008] II. The development trends of organic electroluminescent materials (OLED materials) can be summarized in the following four aspects: 1. Market demand continues to grow: driven by terminal devices, expanding application areas, and a continuously expanding high-end market.

[0009] 2. Domestic substitution is accelerating: technological breakthroughs, capacity expansion, and industrial chain improvement.

[0010] 3. Technological innovation and material upgrading: research and development of new materials and optimization of production processes.

[0011] 4. Competitive Landscape and Market Opportunities: Increased international competition and the potential of blue ocean markets.

[0012] III. Currently, organic electroluminescent devices still face many technical challenges, mainly including the following aspects: 1. Efficiency issue: The luminous efficiency of organic electroluminescent devices is relatively low and needs to be further improved.

[0013] 2. Lifespan issue: Organic materials have poor stability and durability, resulting in a shorter lifespan for devices.

[0014] 3. Color stability issues: The color of organic materials is easily affected by environmental factors such as temperature and humidity, resulting in color instability.

[0015] 4. Manufacturing process issues: The manufacturing process of organic electroluminescent devices is relatively complex and requires further optimization.

[0016] 5. Cost issues: The high cost of organic materials and manufacturing processes limits the large-scale application of organic electroluminescent devices.

[0017] In summary, the OLED materials industry is showing a diversified development trend in terms of market demand, domestic substitution, technological innovation, and competitive landscape, and has broad prospects for the future.

[0018] Therefore, how to develop a long-life, low-driving-voltage organic electroluminescent material with dual host, its preparation method, and organic electroluminescent device are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0019] In view of this, the present invention discloses a host compound, an organic electroluminescent material containing two hosts, and an organic electroluminescent device. By applying the host compound or the organic electroluminescent material containing two hosts of the present invention to an organic electroluminescent device, the driving voltage is reduced, the luminous efficiency is improved, and the service life is extended.

[0020] To achieve the above objectives, the present invention adopts the following technical solution: One object of the present invention is to provide a host compound having the structure shown in general formula one:

[0021] Wherein: A1, A2, and A3 are each independently selected from benzene, naphthalene, anthracene, phenanthrene, dibenzofuran, dibenzothiophene, fluorene, and carbazole; X1 and X2 are each independently selected from O, S, NR5, CR6R7 and SiR8R9; L1, L2, and L0 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C3-C 20 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; R1 and R2 are each independently selected from substituted or unsubstituted C1-C. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C 42 aryl, substituted or unsubstituted C3-C 42 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium; R3, R4, R5, R6, R7, R8, and R9 are each independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted C1-C groups. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium; R 10 R 11 R 12 Each is independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted fluorene, and substituted or unsubstituted carbazole.

[0022] Preferably, Formula 1 specifically includes:

[0023] in, A1, A2, and A3 are each independently selected from benzene and naphthalene; L1, L2, and L0 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 18 aryl, substituted or unsubstituted C3-C 12 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; R1 and R2 are each independently selected from substituted or unsubstituted phosphooxy groups and substituted or unsubstituted C6-C groups. 36aryl, substituted or unsubstituted C3-C 36 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium; R3, R4, R5, R6, R7, R8, and R9 are each independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C3-C6 cycloalkyl, substituted or unsubstituted phosphooxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C 18 aryl, substituted or unsubstituted C3-C 18 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium.

[0024] Preferably, A2 is selected from benzene; R1 and R2 are each independently selected from the following structures, either substituted or unsubstituted: ; In the above structure, any point can be a connection point; R3, R4, R5, R6, R7, R8, and R9 are each independently selected from methyl, ethyl, cyano, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted fluorene, and substituted or unsubstituted carbazole.

[0025] In this invention, "substituted or unsubstituted" means that the group may not be substituted, or may be substituted by one or more substituents; "substituted" means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent, and there is no restriction on the position of substitution, as long as the position is where the hydrogen atom is substituted, that is, the position where the substituent can be substituted, and when two or more substituents are substituted, the two or more substituents may be the same as or different from each other.

[0026] The substituents in the "substituted or unsubstituted" group are selected from fluorine, C1-C... 10 Alkyl, C3-C 20 cycloalkyl, C3-C 20 Heterocyclic alkyl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur.

[0027] In all the groups mentioned above, the hydrogen atoms can be completely unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium.

[0028] Preferably, the host compound is selected from any one of the following compounds:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] .

[0041] A second objective of this invention is to provide an organic electroluminescent material comprising two main components, wherein the organic electroluminescent material comprises a first main component and a second main component, the first main component being the aforementioned main compound, and the second main component being a compound having the structure shown in general formula 2. ; Among them, L3, L4, and L5 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C3-C 20 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; T1, T2, and T3 are each independently selected from hydrogen, substituted, or unsubstituted C1-C. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted germanyl, substituted or unsubstituted C6-C 42 aryl, substituted or unsubstituted C3-C 42 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium.

[0042] Preferably, L3, L4, and L5 are each independently selected from substituted or unsubstituted C6-C. 18 aryl, substituted or unsubstituted C3-C 12Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; T1, T2, and T3 are each independently selected from substituted or unsubstituted C6-C. 36 aryl, substituted or unsubstituted C3-C 36 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium.

[0043] In Formula 2, “substituted or unsubstituted” means that the group may not be substituted or may be substituted by one or more substituents. “Substitution” means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent, and there is no restriction on the position of substitution, as long as the position is where the hydrogen atom is substituted, that is, the position where the substituent can be substituted. When two or more substituents are substituted, the two or more substituents may be the same as or different from each other.

[0044] The substituents in the "substituted or unsubstituted" group are selected from deuterium, fluorine, C1-C 10 Alkyl, deuterium-substituted C1-C 10 Alkyl, C3-C 20 cycloalkyl, C3-C 20 Heterocyclic alkyl, deuterated C3-C 20 Cycloalkyl, deuterium-substituted C3-C 20 Heterocyclic alkyl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur.

[0045] Preferably, the second host material is selected from any one of the following compounds:

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] Where D represents deuterium.

[0054] Preferably, the mass ratio of the first main material to the second main material is (1:99) to (99:1). More preferably, it is (25:75) to (75:25), and even more preferably, it is (30:70) to (70:30).

[0055] A third objective of this invention is to provide a method for preparing an organic electroluminescent material containing two main components, comprising the following steps: Preparation of Formula 1:

[0056] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1 eq), potassium carbonate (2-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (volume ratio 2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq) were added. The reaction was carried out at 40-50℃ for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, extracted with water, and the organic phase was collected. The organic phase was dried with anhydrous magnesium sulfate and evaporated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as eluent to obtain the compound HTA-1 shown. (2) Under nitrogen protection, weigh HTA-1 (1 eq) and add it to the reaction system. Add anhydrous dioxane and triethylamine (2-4 eq). Under nitrogen protection, add it to an ice-water bath and add (Boc)2O (2.2 eq) in batches at 0°C. Heat to room temperature and react for 16 h. After the reaction is completed, quench with water, extract with ethyl acetate, collect the organic phase, dry the organic phase with anhydrous magnesium sulfate, and evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound HTA-2 shown. (3) Under nitrogen protection, weigh HTA-2 (1 eq) and add it to the reaction system. Add dry THF and cool to -78°C under nitrogen protection. Add 2.5M n-butyllithium (2-5 eq) dropwise and react for 1 h. Then heat to 40°C and react for 1 h. Cool to -78°C again and add reactant 3 (2.4 eq) dropwise and react for 1 h. Heat to room temperature and react for 2 h. After the reaction is complete, add saturated ammonium chloride aqueous solution dropwise and extract with ethyl acetate. Collect the organic phase and dry it with anhydrous magnesium sulfate. Then evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound HTA-3 shown. (4) Under nitrogen protection, weigh HTA-3 (1 eq) and put it into the reaction system. Add anhydrous dichloromethane and add it into an ice-water bath under nitrogen protection. Keep the temperature at 0°C and slowly add trifluoroacetic acid (2 eq). Raise the temperature to room temperature and react for 4 hours. After the reaction is completed, rotary evaporation under reduced pressure is used to obtain crude ammonium salt. Wash the crude product with saturated sodium bicarbonate aqueous solution several times. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound HTA-4 shown. (5) Under nitrogen protection, weigh compound HTA-4 (1 eq), reactant 4 (1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction system. Add dry toluene, catalyst tris(dibenzylacetone) bispalladium (0.01-0.03 eq) and 50% tri-tert-butylphosphine (0.02-0.06 eq). Reflux at 40-50℃ for 24 h under nitrogen protection. Stop heating after the reactants have reacted completely. Cool to 25℃, add water to extract and separate the liquid. Collect the organic phase. Add anhydrous magnesium sulfate to the organic phase and dry it. Rotary evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain compound HTA-5 as shown. (6) Under nitrogen protection, weigh compound HTA-5 (1 eq), reactant 5 (1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction system. Add dry toluene, catalyst tris(dibenzylacetone) bispalladium (0.01-0.03 eq) and 50% tri-tert-butylphosphine (0.02-0.06 eq). Reflux at 40-50℃ for 24 h under nitrogen protection. Stop heating after the reactants have reacted completely. Cool to 25℃, add water to extract and separate the liquid. Collect the organic phase. Add anhydrous magnesium sulfate to the organic phase and dry it. Rotary evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound HTA shown. Similarly, the above method can also produce HTB, which will not be described in detail here; Preparation of Formula 2: ; (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1 eq), potassium carbonate (2-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (volume ratio 2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq) were added. The reaction was carried out at 40°C for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25°C, extracted with water, and the organic phase was collected. The organic phase was dried with anhydrous magnesium sulfate and evaporated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as eluent to obtain the compound H2-T-1 shown. (2) Under nitrogen protection, weigh H2-T-1 (1 eq), reactant 3 (1 eq), and potassium carbonate (2-3 eq) into the reaction system, add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq), react at 60°C for 24 h under nitrogen protection, after which cool to 25°C, extract with water and separate the liquid, collect the organic phase, dry the organic phase with anhydrous magnesium sulfate, and evaporate under reduced pressure to obtain crude product; use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain compound H2-T-2 as shown; (3) Under nitrogen protection, weigh H2-T-2 (1 eq), reactant 4 (1 eq), potassium carbonate (2-3 eq) and add them to the reaction system. Add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq). Reflux at 90°C for 24 h under nitrogen protection. After the reaction is completed, cool to 25°C, add water to extract and separate the liquid. Collect the organic phase, add anhydrous magnesium sulfate to dry the organic phase, and rotary evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound H2-T shown.

[0057] A fourth objective of the present invention is to provide an organic electroluminescent device comprising the aforementioned organic electroluminescent material having a dual host.

[0058] Specifically, the organic electroluminescent device includes 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 includes a light-emitting layer; the light-emitting layer includes the aforementioned organic electroluminescent material containing two main bodies.

[0059] Preferably, the light-emitting layer comprises a first host material, a second host material, and a dopant material; The mass ratio of the first main material, the second main material, and the doped material is (1~99):(1~99):(99~1), preferably (1~20):(1~20):(9~1), and more preferably 10:10:1.

[0060] The organic electroluminescent device includes an anode, a hole transport region, an emissive layer, an electron transport region, and a cathode. The emissive layer includes a first host material as shown in Formula 1 and a second host material as shown in Formula 2.

[0061] As an anode material, materials with a large work function are usually preferred to facilitate the injection of holes into the organic material layer.

[0062] The anode materials that can be used for the first electrode of the organic electroluminescent device of the present invention include: metals, such as vanadium, chromium, copper, zinc and gold, or alloys thereof; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO:Al or SnO2:Sb; conductive polymers, such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxo)thiophene] (PEDOT), polypyrrole and polyaniline, but are not limited thereto.

[0063] As a cathode material, materials with a small work function are generally preferred to facilitate electron injection into the organic material layer. The cathode materials that can be used for the second electrode of the organic electroluminescent device of the present invention include: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; multilayer materials, such as LiF / Al or LiO2 / Al; and so on, but are not limited thereto.

[0064] The hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer, and a hole blocking layer, with the light-emitting layer located between the electron blocking layer and the hole blocking layer.

[0065] The hole injection layer material is a material that receives holes from the anode at 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. Hole injection materials include metalloporphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazabenzophenanthrene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinones, and conductive polymers based on polyaniline and polythiophene, etc.

[0066] Hole transport layer materials are materials that can receive holes from the anode or hole injection layer and transport the holes to the light-emitting layer, and have high hole mobility; and hole transport layer materials include, but are not limited to, arylamine-based organic materials, conductive polymers, block copolymers that have both conjugated and non-conjugated parts.

[0067] An electron blocking layer can be disposed between the hole transport layer and the light-emitting layer. Materials known in the art, such as arylamine-based organic materials, can be used as the electron blocking layer.

[0068] The main material of the light-emitting layer is selected from the structure of this invention.

[0069] The hole blocking layer can be disposed between the electron transport layer and the light-emitting layer, and can be made of materials known in the art, such as triazine-based compounds.

[0070] The electron transport layer facilitates electron transport. Electron transport materials are those that advantageously receive electrons from the cathode and transport them to the light-emitting layer, exhibiting high electron mobility. These include, but are not limited to, Al complexes of 8-hydroxyquinoline; complexes containing Alq3; organic free radical compounds; hydroxyflavonoid-metal complexes, etc. The thickness of the electron transport layer can range from 1 nm to 50 nm. Electron transport layers with a thickness of 1 nm or greater have the advantage of preventing a decrease in electron transport properties, while thicknesses of 50 nm or less have the advantage of preventing an increase in driving voltage caused by an excessively thick electron transport layer.

[0071] The electron injection layer can promote electron injection, and the electron injection material preferably has the ability to transport electrons, exhibiting an electron injection effect from the cathode, and demonstrating excellent electron injection effect on the light-emitting layer or light-emitting material. It prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and also possesses excellent thin film forming ability. Specific examples include fluorenones, anthraquinone dimethane, biphenylquinone, thiamethane dioxide, azoles, diazoles, triazoles, imidazoles, perylenetetracarboxylic acid, fluorenemethane, anthrones, and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but are not limited to these.

[0072] Depending on the materials used, the above-mentioned organic electroluminescent devices can be top-emitting, bottom-emitting, or bilaterally emitting.

[0073] Furthermore, the organic electroluminescent device described in this invention can be used in organic solar cells, electronic paper, organic photoreceptors, or organic thin-film transistors.

[0074] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects: 1) The main compound of this invention contains a triarylamine structure, which has the following advantages: 1. Improve hole transport performance: Triarylamines have low ionization potential of amine units, good electron donation, and high hole mobility.

[0075] 2. Improve luminous efficiency: As a light-emitting layer material, it can effectively reduce the total reflection loss and waveguide loss of traditional OLED devices, thereby improving luminous efficiency.

[0076] 3. Extended service life: The triarylamine structure of the compound has good physical and thermal stability, making it difficult for molecules to crystallize and aggregate, thus effectively extending the service life.

[0077] 4. Energy level matching advantage: The introduction of triarylamine structure can adjust the HOMO / LUMO energy levels of the material, making it more compatible with the energy levels of other materials.

[0078] 5. Reduce driving voltage: This helps to improve and balance the transport of charge carriers in the device, thereby reducing the device voltage.

[0079] 2) The main compound of this invention contains benzo[a]hexacyclohexane-9-siliconfluorene, which has the following advantages in organic electroluminescent materials: 1. Unique electronic structure leads to excellent electrical and optical properties: σ-π conjugation effect: In the silicon atom of the fluorene core, the two outer σ orbitals can undergo σ-π conjugation with the adjacent π orbitals. This effect can effectively reduce the lowest unoccupied orbital (LUMO) energy level of the molecule, significantly enhancing the material's electron affinity and electron injection / transport capabilities.

[0080] 2. Rigid framework: The fused ring structure (benzohexacyclohexane) and the silicon fluorene core together form a highly rigid planar or twisted framework, which gives the material a high thermal decomposition temperature and glass transition temperature, making it less prone to decomposition or crystallization when the device generates heat during operation.

[0081] 3. Good film-forming properties: The steric hindrance brought by silicon atoms and their substituents can effectively suppress the close packing of molecules in the solid state, making it easier to form uniform, stable and smooth amorphous films during vacuum evaporation. This is the basis for preparing high-performance multilayer OLED devices.

[0082] 4. Excellent host material: Its wide bandgap and high triplet energy level characteristics make it very suitable as the host material for red, green and even blue phosphorescent devices, which can effectively confine excitons within the emitting layer and improve efficiency.

[0083] 5. Excellent electron transport / injection material: Its low LUMO energy level is conducive to receiving electrons from the cathode and transporting them efficiently.

[0084] 3) The second main material of the present invention contains a triazine structure, which has the following advantages: 1. Enhanced stability and electronic tolerance: The triazine structure gives the compound good stability and electronic tolerance, ensuring the material's performance is stable in the working environment and reducing performance degradation caused by external factors and electronic shocks.

[0085] 2. Enhanced electron injection and transport capabilities: This structure has strong electron-withdrawing properties, which can lower the electron injection energy barrier, making it easier for electrons to be injected into organic materials. At the same time, it increases the migration speed of electrons in the material and improves electron transport efficiency.

[0086] 3. Reduced driving voltage: Triazine structure materials applied to organic electroluminescent devices can significantly reduce the device driving voltage, reduce energy consumption, and improve energy utilization efficiency.

[0087] 4. Improved luminescence performance: Triazine compounds have good luminescence performance and can be used to prepare organic electroluminescent devices. They can improve the current efficiency of the devices, allowing the devices to achieve higher brightness with lower current.

[0088] 5. Extend device lifespan: Triazine-based materials can improve device stability and efficiency, reduce damage and aging during operation, and effectively extend device lifespan.

[0089] 6. Improved thermal stability: Compounds with triazine structure as the core and aryl and other groups forming side chains have good thermal stability, which can ensure that the device can work stably under different temperature environments.

[0090] 7. Improved film-forming properties: Some triazine compounds have improved molecular planarity through design, which enhances the film-forming properties of the material, reduces problems in the production process, and facilitates large-scale production and preparation of high-quality thin-film devices.

[0091] In summary, the organic electroluminescent material containing dual main bodies in this invention, when used in organic electroluminescent devices, can reduce the driving voltage of the organic electroluminescent devices while improving the device's efficiency and lifespan. Attached Figure Description

[0092] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0093] Figure 1 The above is the 1H NMR spectrum of compound H001 prepared in Example 1 of this invention. Detailed Implementation

[0094] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0095] Example 1: Preparation of compound H001

[0096] (1) Under nitrogen protection, reactant 1 (1 eq, CAS: 131167-08-3), reactant 2 (1 eq, CAS: 30418-59-8), and potassium carbonate (2.5 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.02 eq) were added. The reaction was carried out at 40°C for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25°C, extracted with water, and the organic phase was collected. The organic phase was dried with anhydrous magnesium sulfate and evaporated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as eluent to obtain compound H001-1 as shown. Yield: 68.26%. (2) Under nitrogen protection, weigh H001-1 (1 eq) and add it to the reaction system. Add anhydrous dioxane and triethylamine (2.5 eq). Under nitrogen protection, add it to an ice-water bath and add (Boc)2O (2.2 eq) in batches at 0°C. Raise the temperature to room temperature and react for 16 h. After the reaction is complete, quench with water, extract with ethyl acetate, collect the organic phase, dry the organic phase with anhydrous magnesium sulfate, and evaporate under reduced pressure to obtain the crude product. Use dichloromethane / hexane as eluent to purify the crude product by silica gel column chromatography to obtain the compound H001-2 shown. Yield: 73.20%. (3) Under nitrogen protection, weigh H001-2 (1 eq) and add it to the reaction system. Add dry tetrahydrofuran, cool down to -78°C under nitrogen protection, add 2.5M n-butyllithium (2.5 eq) dropwise, react for 1 h, heat up to 40°C and react for 1 h, cool down to -78°C again, add reactant 3 (2.4 eq, CAS: 75-78-5) dropwise and react for 1 h, heat up to room temperature and react for 2 h. After the reaction is completed, add saturated ammonium chloride aqueous solution dropwise, extract with ethyl acetate, collect the organic phase, dry the organic phase with anhydrous magnesium sulfate, and evaporate under reduced pressure to obtain crude product; use dichloromethane / hexane as eluent, purify the crude product by silica gel column chromatography to obtain compound H001-3 as shown; yield: 70.09%; (4) Under nitrogen protection, weigh H001-3 (1 eq) and add it to the reaction system. Add anhydrous dichloromethane and add it to an ice-water bath under nitrogen protection. Slowly add trifluoroacetic acid (2 eq) at 0°C. Heat to room temperature and react for 4 hours. After the reaction is completed, rotary evaporate under reduced pressure to obtain crude ammonium salt. Wash with saturated sodium bicarbonate aqueous solution several times to obtain crude product. Use dichloromethane / hexane as eluent to purify crude product by silica gel column chromatography to obtain compound H001-4 as shown. Yield: 65.23%. (5) Under nitrogen protection, compound H001-4 (1 eq), reactant 4 (1 eq, CAS: 2113-57-7), and sodium tert-butoxide (2 eq) were weighed and added to the reaction system. Dry toluene, catalyst tris(dibenzylacetone) bispalladium (0.02 eq), and 50% tri-tert-butylphosphine (0.04 eq) were added. The mixture was refluxed at 40°C for 24 h under nitrogen protection. Heating was stopped after the reactants had reacted completely. The mixture was cooled to 25°C, extracted with water, and the organic phase was collected. Anhydrous magnesium sulfate was added to the organic phase for drying. The crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as the eluent to obtain compound H001-5 as shown. Yield: 76.33%. (6) Under nitrogen protection, compound H001-5 (1 eq), reactant 5 (1 eq, CAS: 26608-06-0), sodium tert-butoxide (2 eq) were weighed and added to the reaction system. Dry toluene, catalyst tris(dibenzylacetone) bispalladium (0.02 eq) and 50% tri-tert-butylphosphine (0.04 eq) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection. Heating was stopped after the reactants had reacted completely. The mixture was cooled to 25 °C, extracted with water, and the organic phase was collected. Anhydrous magnesium sulfate was added to the organic phase for drying. The crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as the eluent to obtain compound H001 as shown. Yield: 73.89%.

[0097] Characterization: HPLC: 99.95%; Test value ((ESI, m / Z): [M+H]+): 649.39; Elemental analysis results: C: 81.08; H: 4.93; N: 2.25; O: 7.50; Si: 4.44; The proton NMR spectrum is as follows: Figure 1 As shown.

[0098] Example 2: Preparation of compound H2-1

[0099] Under nitrogen protection, reactant 1 (1 eq, CAS: 2681303-14-8), reactant 2 (1 eq, CAS: 1883265-32-4), and potassium carbonate (2.5 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetrakis(triphenylphosphine)palladium (0.02 eq) were added. The mixture was refluxed at 90 °C for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25 °C, extracted with water, and the organic phase was collected. The organic phase was dried with anhydrous magnesium sulfate and evaporated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using dichloromethane / hexane as the eluent to obtain compound H2-1 as shown; yield: 66.87%.

[0100] Characterization: HPLC: 99.90%; Test value ((ESI, m / Z): [M+H]+): 549.54; Elemental analysis results: C: 85.04; H: 4.33; N: 7.78; O: 3.03.

[0101] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the preparation methods of the examples listed above, so they will not be listed one by one here.

[0102] Device Example 1: Fabrication of Organic Electroluminescent Devices: ITO anode: An ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 Å was cleaned twice with distilled water and ultrasonically washed for 30 min. Then it was cleaned twice more with distilled water and ultrasonically washed for 10 min. After washing, it was ultrasonically washed sequentially with methanol, acetone and isopropanol (5 min each time), dried, and then transferred to a plasma cleaner for 5 min to obtain the ITO anode.

[0103] HIL (Hole Injection Layer): In a vapor deposition machine, 200 Å of 4,4',4''-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) is vacuum-deposited onto an ITO anode to form a hole injection layer.

[0104] HTL (Hole Transport Layer): A hole transport layer is formed by vacuum evaporating NPB (i.e., N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) at 400 Å onto the hole injection layer.

[0105] EML (Emitting Layer): The emitting layer comprises a first host material, a second host material, and a guest dopant. After forming a hole injection layer and a hole transport layer, the emitting layer is formed on the HTL: the first host compound (H001) and the second host compound (H2-1) are introduced as hosts into two chambers of a vacuum phase deposition apparatus, and compound Z1 is introduced as a dopant into another chamber; the two host materials are evaporated at a 1:1 ratio, and the dopant material is evaporated simultaneously at different rates, and a doping amount of 3wt% based on the total amount of host and dopant is deposited to form an emitting layer with a thickness of 40nm on the hole transport layer.

[0106] HBL (Hole Blocking Layer): A hole blocking layer is formed by vacuum evaporation of bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) at 100 Åm on the luminescent layer.

[0107] ETL (Electron Transport Layer): 400 Å of 8-hydroxyquinoline aluminum (Alq3) is vacuum-deposited onto the hole-blocking layer to form the electron transport layer.

[0108] EIL (Electron Injection Layer): LiF 210Å is vacuum-deposited on the electron transport layer to form the electron injection layer.

[0109] Cathode: Magnesium and silver are vacuum-deposited at a deposition rate of 1 Å / s on the electron injection layer for 13 nm, with a deposition rate ratio of 1:9, to form the cathode, thus obtaining an organic electroluminescent device.

[0110] Referring to the organic electroluminescent device and its preparation method provided in Device Example 1, other organic electroluminescent compounds were selected to replace the first host compound and the second host compound for the vapor deposition of the host material, and organic electroluminescent devices of the corresponding compounds were prepared.

[0111] The following are the materials used to manufacture the above-mentioned devices: , , , , .

[0112] Device Examples 1-50, Comparative Examples 1-7 and Parallel Examples 1-8 The device fabrication processes of Device Examples 1-50, Comparative Examples 1-7 and Parallel Examples 1-8 are exactly the same, and the same substrate material and electrode material are used. The film thickness of the electrode material is also consistent. The difference is that the two host materials are different. The corresponding first host compound and second host compound in Table 1 are selected respectively. The specific parameters are shown in Table 1.

[0113] Table 1 shows the parameters used in Device Examples 1-50, Comparative Examples 1-7, and Parallel Examples 1-8.

[0114] Table 1

[0115] The comparative example structure is shown below: .

[0116] Performance testing: The driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained in Comparative Examples 1-7, Parallel Examples 1-8, and Device Examples 1-50 were characterized at a brightness of 7000 nits. The test results are shown in Table 2 below.

[0117] Table 2

[0118] As can be seen from Table 2, the driving voltage of the organic electroluminescent devices provided by Device Examples 1-50 of the present invention is 2.76V~3.10V, which is significantly lower than that of Comparative Examples 1-7, and is reduced by 19.18%-29.87% respectively compared with the comparative examples. At the same time, the luminous efficiency is higher than that of Comparative Examples 1-7, which is increased by 24.32%-67.6% respectively compared with the comparative examples. Moreover, the lifetime is significantly improved compared with Comparative Examples 1-7, which is increased by 10.1%-14.67% respectively compared with the comparative examples.

[0119] Therefore, it can be seen that the organic electroluminescent device prepared using the host compound provided by the present invention as the light-emitting layer material has a significantly lower driving voltage and a significantly improved luminous efficiency and lifetime compared with the organic electroluminescent device prepared using comparative compounds E-1, E-2, E-3, E-4, E-5, E-6, E-7, and F-1 as the dual host materials for the light-emitting layer.

[0120] The main reason for this is that, in the main structure, replacing fluorene with silicon fluorene creates σ-π conjugation between the σ orbitals of silicon atoms and the π orbitals of fluorene, effectively lowering the LUMO energy level and making it more conducive to electron injection and transport. Simultaneously, silicon fluorene possesses a high bandgap and low LUMO energy, which can effectively modulate the photoelectric properties of the polymer. Due to the introduction of inorganic silicon and a rigid trapezoidal structure, the glass transition temperature (Tg) of silicon fluorene materials is significantly increased. Silicon fluorene also enhances the mobility of both electrons and holes. Silicon fluorene can achieve extremely high fluorescence quantum yield, which is beneficial for manufacturing high-efficiency devices. In summary, replacing the bridging atom of fluorene with silicon fundamentally optimizes the electronic structure of the material, resulting in more stable thermodynamic properties, more balanced carrier transport capabilities, and higher luminous efficiency, making it an important strategy for designing high-performance OLED materials. Furthermore, the triarylamine structure has good film-forming properties, which can improve the performance and stability of the device, and its strong electron-donating ability can improve electron transport efficiency.

[0121] Furthermore, the above embodiments illustrate the main material of the present invention, the organic electroluminescent material containing two main components, and its applications. However, the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented.

[0122] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0123] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A host compound characterized in that, The host compound has the structure shown in general formula 1: Wherein: A1, A2, and A3 are each independently selected from benzene, naphthalene, anthracene, phenanthrene, dibenzofuran, dibenzothiophene, fluorene, and carbazole; X1 and X2 are each independently selected from O, S, NR5, CR6R7 and SiR8R9; L1, L2, and L0 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C3-C 20 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; R1, R2are each independently selected from the group consisting of substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C 42 aryl, substituted or unsubstituted C3-C 42 heteroaryl, the heteroatoms of which are selected from one or more of oxygen, nitrogen, sulfur, silicon, selenium; R3, R4, R5, R6, R7, R8, R9are each independently selected from the group consisting of hydrogen, deuterium, cyano, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted phosphoalkoxy, substituted or unsubstituted silylalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 heteroaryl, the heteroatoms of which are selected from one or more of oxygen, nitrogen, sulfur, silicon, selenium; R 10 , R 11 , R 12 each independently is selected from the group consisting of hydrogen, deuterium, cyano, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted fluorene, and substituted or unsubstituted carbazole.

2. The host compound according to claim 1, wherein Formula 1 specifically includes: in, A1, A2, and A3 are each independently selected from benzene and naphthalene; L1, L2, and L0 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 18 aryl, substituted or unsubstituted C3-C 12 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; R1, R2are each independently selected from substituted or unsubstituted phosphinyl, substituted or unsubstituted C6-C 36 aryl, substituted or unsubstituted C3-C 36 heteroaryl, the heteroatoms of which are selected from one or more of oxygen, nitrogen, sulfur, silicon, selenium; R3, R4, R5, R6, R7, R8, and R9 are each independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C3-C6 cycloalkyl, substituted or unsubstituted phosphooxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C 18 aryl, substituted or unsubstituted C3-C 18 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium.

3. The host compound according to claim 2, wherein A2 is selected from benzene; R1 and R2 are each independently selected from the following structures, either substituted or unsubstituted: ； In the above structure, any point can be a connection point; R3, R4, R5, R6, R7, R8, and R9 are each independently selected from methyl, ethyl, cyano, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted fluorene, and substituted or unsubstituted carbazole.

4. The host compound according to claim 1, wherein The host compound is selected from any one of the following compounds: 。 5. An organic electroluminescent material containing two main components, characterized in that, The organic electroluminescent material containing two hosts comprises a first host material and a second host material, wherein the first host material is the host compound according to any one of claims 1-4, and the second host material is a compound having the structure shown in general formula II. ； Among them, L3, L4, and L5 are each independently selected from the linking bond, substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C3-C 20 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, and sulfur; T1, T2, T3are each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted phosphoalkyl, substituted or unsubstituted silylalkyl, substituted or unsubstituted germylalkyl, substituted or unsubstituted C6-C 42 aryl, substituted or unsubstituted C3-C 42 heteroaryl, the heteroatoms of which are selected from one or more of oxygen, nitrogen, sulfur, silicon, selenium.

6. The double-host-containing organic electroluminescent material according to claim 5, wherein L3, L4, L5are each independently selected from substituted or unsubstituted C6-C 18 aryl, substituted or unsubstituted C3-C 12 heteroaryl, whose heteroatoms are selected from one or more of oxygen, nitrogen, sulfur; T1, T2, and T3 are each independently selected from substituted or unsubstituted C6-C. 36 aryl, substituted or unsubstituted C3-C 36 Heteroaryl groups, wherein the heteroatoms are selected from one or more of oxygen, nitrogen, sulfur, silicon, and selenium.

7. The double-host-containing organic electroluminescent material according to claim 5, wherein The second host material is selected from any one of the following compounds: Where D represents deuterium.

8. The organic electroluminescent material containing two main bodies according to claim 5, characterized in that, The mass ratio of the first main material and the second main material is (1:99) to (99:1).

9. An organic electroluminescent device, characterized in that, It includes 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 includes a light-emitting layer; the light-emitting layer includes the organic electroluminescent material with dual host as described in claim 5.

10. An organic electroluminescent device according to claim 9, characterized in that, The light-emitting layer comprises a first host material, a second host material, and a doped material; The mass ratio of the first main material, the second main material and the doped material is (1~99):(1~99):(99~1).

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