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

Abstract

This invention provides a host material, an organic electroluminescent material containing two hosts, and an organic electroluminescent device. The structure of the host material is shown in Formula I. The organic electroluminescent material containing two hosts includes a first host material and a second host material. The first host material is the host material shown in Formula I, and the second host material has the structure shown in Formula II. The first host compound of this invention has faster electron mobility, lower operating voltage, higher quantum efficiency, and longer lifespan. By using the two host materials, triplet excitons can be dispersed on two hosts, which can reduce triplet-triplet annihilation. When the two are used as the hosts of the light-emitting layer, the driving voltage of the organic electroluminescent device is reduced, while the efficiency and lifespan of the device are improved.

Description

Technical Field

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

[0002] OLED (Organic Light Emitting Display) refers to the phenomenon where organic semiconductor materials and light-emitting materials emit light through carrier injection and recombination under an electric field. The principle involves using an ITO transparent electrode and a metal electrode as the anode and cathode, respectively. Under a certain voltage, electrons and holes are injected from the cathode and anode into the electron and hole transport layers, respectively. They then migrate through the transport layers to the light-emitting layer, where they meet, forming excitons and exciting the light-emitting molecules. These molecules then emit visible light through radiative relaxation. However, the organic light-emitting materials at the core of OLEDs are susceptible to oxidation and humidity, resulting in a significantly shorter lifespan compared to inorganic materials. Furthermore, the materials at each pixel also face challenges related to light decay. Therefore, further research is needed on OLEDs in terms of luminous efficiency and lifespan.

[0003] OLED devices mainly consist of the following components: an anode, a cathode, an organic semiconductor layer, and a charge transport layer. When a voltage is applied to an OLED device, electrons are injected from the cathode into the organic semiconductor layer, while holes are injected from the anode. These electrons and holes meet in the organic semiconductor layer and combine to form electron-hole pairs, or excitons. These excitons migrate within the organic semiconductor layer, and when they encounter luminescent centers, they release photons, thus generating visible light. Since the radiative transitions of triplet excitons in most organic molecules are forbidden, their contribution to electroluminescence is small. However, by doping with organometallic complexes such as platinum, iridium, and osmium, triplet excitons from organic molecules can be transferred to the triplet state of the metal complex, thereby improving the efficiency of organic light-emitting devices. However, the most critical issues for the large-scale industrialization of organic electroluminescent devices are high device performance and long lifespan. Therefore, how to provide a long-lifespan, low-driving-voltage organic electroluminescent material and device with dual host structures is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a host material, an organic electroluminescent material containing two hosts, and an organic electroluminescent device. The first host compound of the present invention exhibits faster electron mobility, lower operating voltage, higher quantum efficiency, and longer lifespan. By using a dual-host material, triplet excitons can be dispersed on two hosts, reducing triplet-triplet annihilation (TTA). When both hosts are used as the hosts of the light-emitting layer, the driving voltage of the organic electroluminescent device is reduced while simultaneously improving the device's efficiency and lifespan.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a main material, the structure of which is shown in Formula I: in, L1 and L2 are any one of the following: a linking bond, a substituted or unsubstituted C6-C30 arylene, a substituted or unsubstituted C6-C30 heteroarylene, or a substituted or unsubstituted C10-C30 fused ring group; Ar is selected from the following structures: Where * represents a connection site; A is selected from substituted or unsubstituted benzene or naphthalene; R1 is selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted phosphoroxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C3-C42 heteroaryl, wherein the heteroatom is selected from one or a combination of at least two of oxygen, nitrogen, sulfur, silicon, and selenium. R2 is selected from the following groups: Its connection sites are any connectable sites; In Formula I, the hydrogen atom is either substituted with deuterium or not substituted with deuterium.

[0006] Furthermore, L1 and L2 are connecting bonds, substituted or unsubstituted C6-C18 aromatic amino groups, substituted or unsubstituted C3-C18 heteroaromatic amino groups, substituted or unsubstituted C6-C18 aryl groups, and substituted or unsubstituted C3-C18 heteroaromatic groups, wherein the heteroatoms are selected from one or a combination of at least two of oxygen, nitrogen, and sulfur. R1 is selected from substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C3-C36 heteroaryl, and its heteroatom is selected from one or a combination of two of oxygen, nitrogen, sulfur, silicon, and selenium.

[0007] Furthermore, L1 and L2 are selected from the following structures: Its connection point can be any connectable location; R1 is selected from the following structures, whether substituted or unsubstituted: Its connection point can be any connectable location.

[0008] In the above technical solution, "substituted or unsubstituted" means that the group can be unsubstituted or substituted by one or more substituents. "Substitution" means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent. 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 can be the same as or different from each other.

[0009] Furthermore, in the "substituted or unsubstituted" designation, the substituents are selected from deuterium, fluorine, cyano, C1-C10 alkyl, deuterated C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocyclic alkyl, deuterated C3-C20 cycloalkyl, and deuterated C3-C20 heterocyclic alkyl, and the heteroatoms are selected from one or a combination of at least two of oxygen, nitrogen, and sulfur.

[0010] The main material is any one of the following compounds, but is not limited to: .

[0011] The above are some specific structural forms of the main materials, but are not limited to the chemical structures listed. All compounds based on structural formula I, with simple transformations of groups within the defined range, should be included.

[0012] In a second aspect, the present invention provides an organic electroluminescent material containing two main bodies, the organic electroluminescent material containing two main bodies comprising a first main body material and a second main body material, wherein the first main body material is the main body material described in the first aspect, and the second main body material has the structure shown in Formula II: R3, R4, and R5 are each independently selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C10-C30 fused cyclic group, substituted or unsubstituted phosphoxy group, and substituted or unsubstituted silyl group. L3, L4, and L5 are selected from any one of the following: linking bonds, substituted or unsubstituted C6-C30 arylene groups, substituted or unsubstituted C6-C30 heteroarylene groups, and substituted or unsubstituted C10-C30 fused ring groups; The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, wherein the heteroatom is O, S, N, P, B or Si.

[0013] The substituents include deuterium, fluorine, cyano, or C1-C6 straight-chain or branched alkyl groups and phenyl groups.

[0014] Furthermore, L3, L4, and L5 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene.

[0015] R3 and R4 are independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, furanyl, phenyl-furanyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, tri-benzofuranyl, pyrene-furanyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-thiophene, fluorenyl, diphenyl-fluorenyl, dibenzocarbazoyl, naphthiobenzocarbazoyl, phenanthiobenzocarbazoyl, phenylbenzoxazole, and benzene, respectively. The following are all of the following: phenylnaphthooxazole, phenylphenanthreneoxazole, phenylcarbazooxazole, phenylnaphthooxazole, phenyldibenzofuranoxazole, phenyldibenzofluorenoxazole, phenyltriphenylbenzooxazole, phenylbenzothiazole, phenylnaphthothiazole, phenylphenanthrenethiazole, fluoranyl, phenyl, pyrene, naphthobenzofluorenyl, peryl, naphthothianyl, triphenyl, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, and benzonaphthoselenophenolyl.

[0016] R5 is independently selected from any one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, phenanthryl, fluorenyl, and hydroxyl.

[0017] The second host material is selected from any one of the following compounds: .

[0018] Preferably, the mass ratio of the first main material to the second main material is 1:99-99:1, such as 1:99, 1:95, 1:90, 1:85, 1:83, 1:80, 1:75, 2:98, 5:95, 8:92, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 38:62, 40:60, 45:55, 50:50, 55:45, 58:42, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 88:12, 90:10, 95:5, 98:2, or 99:1, etc.

[0019] The present invention also provides a method for preparing the above-mentioned dual-host organic electroluminescent material.

[0020] The reaction route for compound I-1 is as follows: The specific preparation method of compound formula I-1 includes the following steps: Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), and potassium carbonate (2-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (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 separated by stirring. After standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain the intermediate compound Ar-a shown. Under nitrogen protection, intermediate compound Ar-a (1 eq), pinacol diborate (1-1.2 eq), potassium acetate (2.5-3 eq), tris(dibenzylacetone)palladium (0.01-0.03 eq), X-phos (0.08-0.24 eq), and 1,4-dioxane were added to a three-necked flask. The mixture was heated to 90-110 °C and refluxed for 20-24 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-1-a shown. Under nitrogen protection, reactant 4 (1 eq), reactant 5 (1-1.2 eq), and potassium carbonate (2-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq) were added. The reaction was carried out at 90-110℃ for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, extracted with water, and separated by stirring. After standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-1-b shown. Under nitrogen protection, compound I-1-b (1 eq), reactant 6 (1-1.2 eq), and potassium carbonate (3-4 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq) were added. The mixture was refluxed at 90-110℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-1-c shown. Under nitrogen protection, compound I-1-c (1 eq), compound I-1-a (1-1.2 eq), and potassium carbonate (3-4 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.05-0.08 eq) were added. The mixture was refluxed at 90-110℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-4 shown. Under nitrogen protection, intermediate compound I-1 (1 eq), intermediate compound I-4 (1-1.2 eq), and potassium carbonate (3-4 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.01-0.05 eq) were added. The mixture was refluxed at 90-110℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain compound I-1 as shown. The reaction route for compound I-2 is as follows: .

[0021] Furthermore, the preparation method of Formula II specifically includes the following steps: The specific synthesis route is as follows: Specific preparation method of Formula II: Weigh reactant 1 (1 eq), reactant 2 (1-1.2 eq), and sodium tert-butoxide (2-3 eq) and add them sequentially to a reaction vessel. Then add toluene as a reaction solvent. Under nitrogen protection, add catalysts Pd2(dba)3 (0.01-0.03 eq) and P(t-Bu)3 (0.02-0.06 eq). Reflux at 100-120℃ for 20-24 hours under nitrogen protection, then cool to 25℃, add purified water, stir for 30 minutes, allow to stand for separation, separate the layers, and perform column chromatography to obtain intermediate formula II-1.

[0022] Weigh intermediate formula II-1 (1 eq), reactant 3 (1-1.2 eq), and sodium tert-butoxide (2-3 eq) and add them sequentially to a reaction vessel. Then add toluene as a reaction solvent. Under nitrogen protection, add catalysts Pd2(dba)3 (0.01-0.03 eq) and P(t-Bu)3 (0.02-0.06 eq). Reflux at 100-120℃ for 20-24 hours under nitrogen protection, then cool to 25℃, add purified water, stir for 30 minutes, allow to stand for separation, separate the layers, and perform column chromatography to obtain formula II.

[0023] Thirdly, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; the organic electroluminescent material layer comprising a light-emitting layer; the light-emitting layer comprising a doped material and a dual-host organic electroluminescent material as described above.

[0024] The mass ratio of the dual-host organic electroluminescent material to the doped material is (1~99):(99~1), for example, 1:99, 1:95, 1:90, 1:85, 1:83, 1:80, 1:75, 2:98, 5:95, 8:92, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 38:62, 40:60, 45:55, 50:50, 55:45, 58:42, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 88:12, 90:10, 95:5, 98:2, or 99:1, etc.

[0025] More specifically, 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 of Formula I and a second host material of Formula II.

[0026] As an anode material, a material with a high work function is generally preferred to facilitate hole injection into the organic material layer. 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] The main material of the light-emitting layer is selected from the structure of this invention.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Depending on the materials used, the above-mentioned organic electroluminescent devices can be top-emitting, bottom-emitting, or bilaterally emitting.

[0036] 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.

[0037] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a combination of a first host compound with a specific structure and a second host compound with a specific structure. The first host material uses a molecule with a triazine backbone, which is beneficial for electron injection and output. The benzofuran-phenanthrene moiety is beneficial for hole injection and transport. The bipolar combination promotes a more balanced injection and transport of electrons and holes, resulting in a wider composite region that is more centrally located in the light-emitting layer. This helps to improve exciton formation efficiency, reduce driving voltage, and improve device efficiency and stability. Furthermore, the rigid polycyclic structure endows the molecule with extremely high glass transition temperature and thermal decomposition temperature, giving the device a long operating life. Combined with a second host compound with a triarylamine backbone, the prepared organic electroluminescent device exhibits a lower driving voltage and more stable materials. Attached Figure Description

[0038] Figure 1 This is the 1H NMR spectrum of compound R011. Detailed Implementation

[0039] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0040] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible; however, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0041] Example 1: Preparation of compound R011 Under nitrogen protection, reactant 1 (CAS: 13922-41-3) (1 eq), reactant 2 (CAS: 73183-34-3) (1.2 eq), potassium carbonate (3 eq), toluene, ethanol, water (2:1:1), and catalyst tetra(triphenylphosphine)palladium (0.05 eq) were added to a three-necked flask. The reaction was carried out at 50°C for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25°C, extracted with water, and separated by stirring. After standing and separating the layers, the mixture was purified by column chromatography to obtain the intermediate compound R011-1 (yield 74.9%). Under nitrogen protection, intermediate R011-1 (1 eq), pinacol diborate (CAS: 73183-34-3) (1.2 eq), potassium acetate (3 eq), tris(dibenzylacetone)dipalladium (0.02 eq), X-phos (0.08 eq), and 1,4-dioxane were added to a three-necked flask. The mixture was heated to 100 °C and refluxed for 24 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate R011-2 (yield 69.7%). Under nitrogen protection, reactant 4 (CAS: 13922-41-3 1 eq), reactant 5 (CAS: 73183-34-3 1.2 eq), and potassium carbonate (3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetrakis(triphenylphosphine)palladium (0.05 eq) were added. The reaction was carried out at 110℃ for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, extracted with water, and separated by stirring. After standing, the mixture was allowed to separate into layers. After separation, the intermediate compound R011-3 was purified by column chromatography to obtain the intermediate compound R011-3 (yield 75.7%). Under nitrogen protection, intermediate compound R011-3 (1 eq), reactant 6 (CAS: 1101866-01-61.2 eq), and potassium carbonate (3 eq) were weighed and added to the reaction system. Toluene, ethanol, water (2:1:1) and catalyst tetra(triphenylphosphine)palladium (0.05 eq) were added. The reaction was carried out at 110 °C for 24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25 °C, extracted with water, and separated by stirring. After standing and separating the layers, the mixture was purified by column chromatography to obtain intermediate compound R011-4 (yield 71.3%). Under nitrogen protection, intermediates R011-4 (1 eq), R011-2 (1.2 eq), potassium carbonate (3 eq), tetra(triphenylphosphine)palladium (0.03 eq), tetrahydrofuran, and water were added to a three-necked flask. The mixture was heated to 90°C and refluxed for 24 hours. After the reaction was complete, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate R011 (yield 78.3%; measured value: 769.38; HPLC>99.9%; elemental analysis: C, 78.72; H, 4.16; N, 5.57; O, 2.18; Se, 10.37). The 1H NMR spectrum of compound R011 is shown below. Figure 1 As shown.

[0042] Example 2: Preparation of compound H028 Weigh N-([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-3-amine (1 eq), 10-chloro-2-phenylphenanthrene[3,4-d]oxazole (1 eq), and sodium tert-butoxide (2 eq) into a reaction flask. Add toluene, and under nitrogen protection, add catalysts Pd2(dba)3 (0.01 eq) and P(t-Bu)3 (0.02 eq). Reflux at 120 °C for 24 hours under nitrogen protection, then cool to 25 °C. Add 200 mL of purified water, stir for 30 minutes, allow to stand for separation, separate the layers, and perform column chromatography to obtain product H028 (test value: 614.56; yield: 77.0%; HPLC > 99%; elemental analysis: C, 87.62; H, 5.11; N, 4.65; O, 2.72).

[0043] It should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of Examples 1 and 2 listed above, so they will not be described in detail here.

[0044] Organic electroluminescent devices were prepared using compound R011 prepared in Example 1 and compound H028 prepared in Example 2. Specifically, the preparation method of the organic electroluminescent devices is as follows: (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 Å was washed twice with distilled water and ultrasonically washed for 30 min. Then it was washed twice 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.

[0045] (2) In the vapor deposition machine, HIL is vacuum vapor deposited on the ITO anode surface obtained in step (1) with a thickness of 200 Å to obtain a hole injection layer.

[0046] (3) A hole transport layer is obtained by vacuum evaporation of HTL on the surface of the hole injection layer obtained in step (2) with a thickness of 400 Å.

[0047] (4) A light-emitting layer material is deposited on the surface of the hole transport layer by evaporation. A linear gradient co-evaporation method is used to obtain a thickness of 300 Å to obtain a light-emitting layer. The material of the light-emitting layer includes a dual host material and a dopant material. The mass ratio of the first host compound and the second host compound is 60:40, and the mass ratio of the dual host material and the dopant material is 10:1. The dual host materials are the host materials provided in Comparative Examples 1-18 and Device Examples 1-30, respectively.

[0048] (5) A hole blocking layer is formed by vapor deposition of BAlq on the surface of the light-emitting layer obtained in step (4) with a thickness of 100 Å.

[0049] (6) Vacuum vapor deposition of ETL on the surface of the hole blocking layer obtained in step (5) with a thickness of 400 Å is obtained to obtain the electron transport layer.

[0050] (7) Vacuum vapor deposition of EIL with a thickness of 15 Å is performed on the surface of the electron transport layer obtained in step (6); an electron injection layer is obtained.

[0051] (8) 1500 Å of Al is deposited on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0052] The structure of the material used in the above preparation method is as follows: Performance testing: The driving voltage, luminous efficiency and lifetime of the organic electroluminescent devices obtained in Comparative Examples 1-24 and Device Examples 1-30 were characterized at a brightness of 5000 nits. The test results are shown in Table 1 below.

[0053] The comparative example structure is as follows: Table 1 As can be seen from Table 1, the driving voltage of the organic electroluminescent devices provided by Device Examples 3-30 and Comparative Examples 17-24 of the present invention is 3.71-4.83V, which is significantly lower than the driving voltage of Comparative Examples 1-16. At the same time, the luminous efficiency is higher than that of Comparative Examples 1-16, and the lifetime is significantly improved compared with Comparative Examples 1-16.

[0054] Because the organic electroluminescent compound provided in this invention optimizes the hole injection barrier, it effectively reduces the operating voltage of the device, improves the luminous efficiency, increases the glass transition temperature, and extends the material's lifespan.

[0055] In summary, compared with organic electroluminescent devices prepared using comparative compounds E-1, E-2, E-3, E-4, E-5, E-6, E-7, and E-8 as dual host materials for the light-emitting layer, the organic electroluminescent device prepared by the present invention has a lower band gap, which reduces the driving voltage; it also suppresses structural accumulation and improves the service life.

[0056] The applicant declares that the present invention is illustrated through the above embodiments to describe the main material, the organic electroluminescent material containing two main components, and the organic electroluminescent device of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A main material, characterized in that, The structure of the main material is shown in Formula I: ； in, L1 and L2 are any one of the following: a linking bond, a substituted or unsubstituted C6~C30 arylene, a substituted or unsubstituted C6~C30 heteroarylene, or a substituted or unsubstituted C10~C30 fused ring group; Ar is selected from the following structures: ； Where * represents a connection site; A is selected from substituted or unsubstituted benzene or naphthalene; R1 is selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted phosphoroxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C3-C42 heteroaryl, wherein the heteroatom is selected from one or a combination of at least two of oxygen, nitrogen, sulfur, silicon, and selenium. R2 is selected from the following groups: ； Its connection sites are any connectable sites; In Formula I, the hydrogen atom is either substituted with deuterium or not substituted with deuterium.

2. The main material according to claim 1, characterized in that, L1 and L2 are connecting bonds, substituted or unsubstituted C6-C18 aromatic amino groups, substituted or unsubstituted C3-C18 heteroaromatic amino groups, substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C3-C18 heteroaromatic groups, and their heteroatoms are selected from one or a combination of at least two of oxygen, nitrogen, and sulfur. R1 is selected from substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C3-C36 heteroaryl, and its heteroatom is selected from one or a combination of two of oxygen, nitrogen, sulfur, silicon, and selenium.

3. The main material according to claim 1, characterized in that, L1 and L2 are selected from the following structures: ； Its connection sites are any connectable sites. R1 is selected from the following structures, whether substituted or unsubstituted: ； Its connection point can be any connectable location.

4. The main material according to claim 1, characterized in that, The substituents in the "substituted or unsubstituted" group are selected from deuterium, fluorine, cyano, C1-C10 alkyl, deuterated C1-C10 alkyl, C3-C20 cycloalkyl, C3-C20 heterocyclic alkyl, deuterated C3-C20 cycloalkyl, and deuterated C3-C20 heterocyclic alkyl, and the heteroatoms are selected from one or a combination of at least two of oxygen, nitrogen, and sulfur.

5. The main material according to claim 1, characterized in that, The main material is any one of the following compounds: 。 6. An organic electroluminescent material containing two main components, characterized in that, The dual-host organic electroluminescent material comprises a first host material and a second host material, wherein the first host material is the host material according to any one of claims 1-5, and the second host material has the structure shown in Formula II: ； R3, R4, and R5 are each independently selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C10-C30 fused cyclic group, substituted or unsubstituted phosphoxy group, and substituted or unsubstituted silyl group. L3, L4, and L5 are selected from any one of the following: linking bonds, substituted or unsubstituted C6-C30 arylene groups, substituted or unsubstituted C6-C30 heteroarylene groups, and substituted or unsubstituted C10-C30 fused ring groups; The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, wherein the heteroatom is O, S, N, P, B or Si; The substituents include deuterium, fluorine, cyano, or C1-C6 straight-chain or branched alkyl groups and phenyl groups.

7. The organic electroluminescent material containing two main bodies according to claim 6, characterized in that, L3, L4, and L5 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene; R3 and R4 are independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, furanyl, phenyl-furanyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, tri-benzofuranyl, pyrene-furanyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-thiophene, fluorenyl, diphenyl-fluorenyl, dibenzocarbazoyl, naphthiobenzocarbazoyl, phenanthiobenzocarbazoyl, phenylbenzoxazole, and benzene, respectively. The following are all of the following: phenylnaphthooxazole, phenylphenanthreneoxazole, phenylcarbazooxazole, phenylnaphthooxazole, phenyldibenzofuranoxazole, phenyldibenzofluorenzooxazole, phenyltriphenylbenzooxazole, phenylbenzothiazole, phenylnaphthothiazole, phenylphenanthrenethiazole, fluoranyl, phenyl, pyrene, naphthobenzofluorenyl, peryl, naphthothianyl, triphenylene, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, and benzonaphthoselenophenolyl. R5 is independently selected from any one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, phenanthryl, fluorenyl, and hydroxyl.

8. The organic electroluminescent material containing two main bodies according to claim 6, characterized in that, The second host material is selected from any one of the following compounds: 。 9. The organic electroluminescent material containing two main bodies according to claim 6, characterized in that, The mass ratio of the first main material to the second main material is 1:99-99:

1.

10. An organic electroluminescent device, characterized in that, 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; the organic electroluminescent material layer includes a light-emitting layer; the light-emitting layer includes a doped material and a dual-host organic electroluminescent material as described in any one of claims 6-9.

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