Organic electroluminescent material containing double hosts, preparation method and organic electroluminescent device

Abstract

The invention belongs to the field of organic electroluminescent materials, and discloses an organic electroluminescent material containing double hosts, a preparation method and an organic electroluminescent device. The double-host-containing organic electroluminescent material comprises a first host material and a second host material, the first host material is a compound having a structure represented by a general formula (1), and the second host material is a compound having a structure represented by a general formula (2). According to the organic electroluminescent device, triplet excitons are dispersed on two main bodies by using a double-main-body material, triplet-triplet annihilation is reduced, the driving voltage of the organic electroluminescent device is reduced, the luminous efficiency of the device can be improved, and the service life of the device can be prolonged.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescent materials, and in particular relates to an organic electroluminescent material containing double hosts, a preparation method and an organic electroluminescent device. Background Art

[0002] Organic light-emitting diodes (OLEDs) can be used to manufacture new display products as well as new lighting products. The market application prospects are very broad. Currently, OLED display technology has been applied to smart phones, tablet computers and other fields. However, compared with the actual product application requirements, the performance of OLED, such as luminous efficiency and service life, needs to be further improved.

[0003] The OLED structure includes an electrode film layer and an organic functional material sandwiched between different electrode film layers. As a current device, when a voltage is applied to the electrodes at both ends of the OLED, the positive and negative charges in the organic layer functional material film layer are separated by the electric field, and the positive and negative charges are further recombined in the light-emitting layer, that is, OLED electroluminescence is generated. Since the radiative transition of triplet excitons of most organic molecules is forbidden and contributes little to electroluminescence, the triplet excitons of organic molecules can be transferred to the triplet state of the metal complex by doping with organic metal complexes such as platinum, iridium, and osmium, thereby improving the efficiency of organic light-emitting devices. Therefore, the efficiency of OLEDs can be improved by doping with host and guest in the light-emitting layer. However, triplet excitons will produce triplet-triplet annihilation (TTA) during the transfer process, resulting in energy loss, causing the efficiency of organic light-emitting devices to roll off.

[0004] At present, the poor performance of organic electroluminescent devices is still a technical problem that needs to be urgently solved during their use. For example, there are problems such as excessively high driving voltage, low luminous efficiency or short life, which all affect the application areas of organic electroluminescent devices.

[0005] Therefore, how to provide an organic electroluminescent material containing a dual host with a long life and a low driving voltage and a preparation method thereof and an organic electroluminescent device is a technical problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In view of this, the present invention discloses an organic electroluminescent material containing a double host, a preparation method and an organic electroluminescent device. By using a double host material to disperse triplet excitons on two hosts, triplet-triplet annihilation (TTA) is reduced, and the driving voltage of the organic electroluminescent device is reduced while the luminous efficiency and service life of the device are improved.

[0007] It should be noted that the present invention provides an organic electroluminescent device with a dual-host structure. By using the dual-host material, triplet excitons can be dispersed on two hosts, which can reduce triplet-triplet annihilation (TTA). When the two are used as the hosts of the light-emitting layer, the driving voltage of the organic electroluminescent device can be reduced while improving the efficiency and life of the device.

[0008] In order to achieve the above purpose, the following technical solutions are adopted: An organic electroluminescent material containing two hosts, the organic electroluminescent material containing two hosts comprising a first host material and a second host material, wherein the mass ratio of the first host material to the second host material is 1:99-99:1; the first host material has a structure shown in general formula 1, and the second host material has a structure shown in general formula 2: ; in, R 1 , R 2 , R 3 , D1, D2, and D3 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, or substituted or unsubstituted C6-C18 deuterated aryl, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur; L 1 is selected from substituted or unsubstituted C6-C18 aryl; L 2 , L 3 Each is independently selected from a connecting bond, a substituted or unsubstituted C6-C18 aryl group.

[0009] Further, D1 and D2 are each independently selected from substituted or unsubstituted C6-C18 aryl groups; D3 is selected from substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C6-C36 deuterated aryl, substituted or unsubstituted C3-C30 heteroaryl; R 1 , R 2 , R 3 Each is independently selected from the following structures and any combination thereof: .

[0010] Furthermore, D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl; D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, triphenylene; D3 is selected from substituted or unsubstituted (C6-C30)aryl, substituted or unsubstituted (C3-C30)heteroaryl; L2 is the connecting key, L 3 It is a connecting bond or a phenyl group or a naphthyl group.

[0011] In the above technical scheme, the "substituted or unsubstituted" means that the group may not be substituted, or may be substituted by one or more substituents, and the "substituted" means that the hydrogen atom bonded to the carbon atom of the compound is changed into another substituent, and the position of the substitution is not limited, as long as the position is the position 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.

[0012] Furthermore, the heteroaryl group includes monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom, and the heteroatoms include but are not limited to O, S, and N.

[0013] Further, the substituted group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, 3-membered to 10-membered heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen or sulfur; or the substituted group in the "substituted or unsubstituted" is selected from the following structures: .

[0014] Furthermore, the general formula 1 specifically has the following structure, but is not limited thereto: .

[0015] Furthermore, the general formula 2 is selected from any one of the following compounds:

[0016] .

[0017] The present invention also provides a method for preparing an organic electroluminescent material containing two hosts, which specifically includes a method for preparing the first host material and the second host material, as follows: 1. The preparation method of the general formula 1 specifically comprises the following steps: (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), and potassium carbonate (2-3 eq) were weighed and placed in a reaction system, and THF, water, and catalyst tetrakis(triphenylphosphine)palladium (0.02-0.03 eq) were added. The mixture was refluxed at 70-80°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R-1 shown; (2) Under nitrogen protection, weigh R-1 (1 eq), add dichloromethane, FeCl 3 (5eq), stirred at room temperature for 0.5h, methanol was added to separate the organic layer, dried by spin drying, and column chromatography to obtain the compound R-2 shown; (3) Under nitrogen protection, compound R-2 (1 eq), reactant 3 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and put into the reaction system, and toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120°C for 24 h under nitrogen protection, and then cooled to 25°C. Purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R-3 shown; (4) Under nitrogen protection, compound R-3 (1 eq), reactant 4 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and put into the reaction system, and toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120°C for 24 h under nitrogen protection, and then cooled to 25°C. Purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R-4 shown; (5) Under nitrogen protection, compound R-4 (1 eq), reactant 5 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and put into the reaction system, and toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120°C for 24 h under nitrogen protection, and then cooled to 25°C. Purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound represented by formula 1; The specific synthetic route is as follows: .

[0018] 2. The preparation method of the general formula 2 specifically comprises the following steps: (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), and potassium carbonate (3-4 eq) were weighed and placed in a reaction system, and toluene, ethanol, water, and catalyst tetrakis(triphenylphosphine)palladium (0.05-0.08 eq) were added. The mixture was refluxed at 90°C for 24 h under nitrogen protection, then cooled to 25°C, filtered, and subjected to solid column chromatography to obtain the compound H-1 shown; (2) Under nitrogen protection, weigh H-1 (1 eq), reactant 2-1 (1-1.2 eq), and potassium carbonate (3-4 eq) into the reaction system, add toluene, ethanol, water, and catalyst tetrakis(triphenylphosphine)palladium (0.05-0.08 eq), reflux at 90-100°C for 24 h under nitrogen protection, then cool to 25°C, filter, and perform solid column chromatography to obtain the compound H-2 shown; (3) Under nitrogen protection, weigh H-2 (1 eq), reactant 2-2 (1-1.2 eq), and potassium carbonate (3-4 eq) into the reaction system, add toluene, ethanol, water, and catalyst tetrakis(triphenylphosphine)palladium (0.05-0.08 eq), reflux at 90-100°C for 24 h under nitrogen protection, then cool to 25°C, filter, and perform solid column chromatography to obtain the compound H (Formula 2). The specific synthetic route is as follows: .

[0019] Furthermore, the present invention also seeks to protect the use of the above-mentioned organic electroluminescent material containing a double host in the preparation of an organic electroluminescent device.

[0020] Specifically, the organic electroluminescent device comprises a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; and the organic electroluminescent material layer comprises a light-emitting layer; the light-emitting layer comprises a doping material and the organic electroluminescent material containing a double host; Wherein, the mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1~99):(99~1).

[0021] More specifically, the organic electroluminescent device comprises an anode, a hole transport region, a light emitting layer, an electron transport region and a cathode. The light emitting layer comprises a first host material of Formula 1 and a second host material of Formula 2.

[0022] As the anode material, a material with a large work function is generally preferred so that holes can be smoothly injected 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 SnO 2 :Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole and polyaniline, but not limited thereto.

[0023] As the cathode material, a material with a small work function is generally preferred so that electrons can be smoothly injected 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 structure materials, such as LiF / Al or LiO 2 / Al; and so on, but not limited to.

[0024] The hole injection layer material is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. The hole injection material includes metal porphyrins, oligothiophenes, organic materials based on arylamines, organic materials based on hexanitrile hexaazatriphenylene, organic materials based on quinacridone, organic materials based on perylene, anthraquinone, and conductive polymers based on polyaniline and polythiophene, etc.

[0025] The hole transport layer material is a material that can receive holes from the anode or the hole injection layer and transport the holes to the light-emitting layer and has a high hole mobility; and the hole transport layer material includes organic materials based on aromatic amines, conductive polymers, block copolymers having both conjugated parts and non-conjugated parts, etc., but is not limited thereto.

[0026] The electron blocking layer may be provided between the hole transport layer and the light emitting layer. As the electron blocking layer, a material known in the art, for example, an arylamine-based organic material may be used.

[0027] The host material of the light-emitting layer is selected from the structure of the present invention.

[0028] The hole blocking layer may be disposed between the electron transport layer and the light emitting layer, and a material known in the art, such as a triazine-based compound, may be used.

[0029] The electron transport layer can promote electron transport. The electron transport material is a material that is advantageous in receiving electrons from the cathode and transporting the electrons to the light-emitting layer and has a high electron mobility. It includes: Al complexes of 8-hydroxyquinoline; Alq 3 The thickness of the electron transport layer may be 1 nm to 50 nm, and an electron transport layer having a thickness of 1 nm or more has the advantage of preventing the electron transport characteristics from being reduced, and a thickness of 50 nm or less has the advantage of preventing the increase in driving voltage caused by the electron transport layer being too thick.

[0030] The electron injection layer can promote electron injection, and the electron injection material preferably has the ability to transport electrons, has an effect of injecting electrons from the cathode, has an excellent electron injection effect on the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer, and in addition, has excellent film forming ability. Specific examples thereof include fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, azole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but are not limited thereto.

[0031] According to the materials used, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0032] Furthermore, the organic electroluminescent device of the present invention can be used in organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0033] It can be seen from the above technical solution that the present invention has the following beneficial effects: 1) When the first host material changes the fusion position of phenanthrene and furan, its molecular structure changes and has a high T1 energy level, which prevents the energy backtransfer from the guest to the host, so that it can have high device efficiency and long life host characteristics under the condition of increased driving temperature.

[0034] 2) While reducing the driving voltage of organic electroluminescent devices, it can also improve the efficiency and life of the devices, and has good application effects and industrial prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound R010 provided in the examples of the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the related drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The invention specifically discloses an organic electroluminescent material containing double hosts, a preparation method and an organic electroluminescent device.

[0039] It should be noted that the numerical values ​​given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0040] Example 1: Preparation of Compound R010

[0041]

[0042] Under nitrogen protection, reactant 1 (CAS No.: 2361279-68-5) (141 mmol), reactant 2 (CAS No.: 4688-76-0) (141 mmol), and potassium carbonate (423 mmol) were weighed and put into the reaction system. 1000 ml of tetrahydrofuran, 500 ml of purified water, and catalyst tetrakis(triphenylphosphine)palladium (2.82 mmol) were added. The mixture was refluxed at 70°C for 24 h under nitrogen protection, then cooled to 25°C, 500 ml of purified water was added, and the mixture was allowed to stand for 30 min to separate the layers. The mixture was separated and subjected to column chromatography to obtain the compound R010-1 (test value: 354.88, 36.8 g, yield: 73.7%).

[0043]

[0044] Under nitrogen protection system, weigh R010-1 (23mmol), add dichloromethane (920ml), FeCl 3(115 mmol), stirred at room temperature for 0.5 h, methanol (460 ml) was added, the organic layer was separated, dried by spin drying, and column chromatography was performed to obtain the compound R010-2 (test value: 353.01, 7.16 g, yield: 88.2%).

[0045]

[0046] Under nitrogen protection, compound R010-2 (18.8 mmol), reactant 3 (18.8 mmol), sodium tert-butoxide (37.6 mmol) were weighed and put into the reaction system, and toluene (100 ml), catalyst tris(dibenzylideneacetone) palladium (0.376 mmol) and tri-tert-butylphosphine (0.752 mmol) were added. The mixture was refluxed at 120 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C. Pure water (100 ml) was added. After stirring for 30 min, the mixture was allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R010-3 shown (test value: 409.6, 5.6 g, yield: 75.3%).

[0047]

[0048] Under nitrogen protection, compound R010-3 (17.8 mmol), reactant 4 (17.8 mmol), sodium tert-butoxide (35.6 mmol) were weighed and put into the reaction system, and toluene (100 ml), catalyst tris(dibenzylideneacetone) palladium (0.356 mmol) and tri-tert-butylphosphine (0.712 mmol) were added. The mixture was refluxed at 120 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C. Pure water (100 ml) was added. After stirring for 30 min, the mixture was allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R010-4 shown (test value: 564.51, 7.75 g, yield: 77.2%).

[0049]

[0050] Under nitrogen protection, compound R010-4 (13.3 mmol), reactant 5 (13.3 mmol), sodium tert-butoxide (26.6 mmol) were weighed and put into the reaction system, and toluene (80 ml), catalyst tris(dibenzylideneacetone) palladium (0.266 mmol) and tri-tert-butylphosphine (0.532 mmol) were added. The mixture was refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C. Pure water (80 ml) was added. After stirring for 30 min, the mixture was allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R010 shown (test value: 652.80, 6.57 g, yield: 75.77%), and its HPLC purity was greater than 99%.

[0051] Example 2: Preparation of Compound H004 ; Under nitrogen protection, reactant 1 (cas: 108-77-0) (271.14 mmol), reactant 2 (cas: 98-80-6) (271.14 mmol), and potassium carbonate (813.43 mol) were weighed and put into the reaction system. 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol) were added. The mixture was refluxed at 90 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C, filtered, and solid column chromatography was performed to obtain the compound H004-1 shown (test value: 225.49, 39.4 g, yield 64.7).

[0052] ; Under nitrogen protection, H004-1 (132.71 mmol), reactant 2-1 (cas: 98-80-6) (132.71 mmol), potassium carbonate (398.12 mol) were weighed and put into the reaction system, 500 ml of toluene, 250 ml of ethanol, 250 ml of water, catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol) were added, refluxed at 90 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, filtered, and solid column chromatography was performed to obtain the compound H004-2 shown (test value: 267.56, 23 g, yield 64.5%).

[0053]

[0054] Under nitrogen protection, H004-2 (74.71 mmol), reactant 2-2 (cas: 374538-04-2) (74.71 mmol), potassium carbonate (224.12 mol) were weighed and put into the reaction system, and 200 ml of toluene, 100 ml of ethanol, 100 ml of water, and catalyst tetrakis(triphenylphosphine)palladium (3.74 mmol) were added. The mixture was refluxed at 90 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C, filtered, and solid column chromatography was performed to obtain the compound H004 shown (test value: 391.52, 16 g, yield 52.3%).

[0055] It should be noted that other compounds of the present invention can be obtained by referring to the preparation methods of Examples 1 and 2 listed above, so they will not be described in detail here.

[0056] An organic electroluminescent device was prepared using the compound R010 prepared in Example 1 and the compound H004 prepared in Example 2. Specifically, the preparation method of the organic electroluminescent device is as follows: ITO anode: The ITO (indium tin oxide) glass substrate with a coating thickness of 1500Å was cleaned twice in distilled water, ultrasonically washed for 30 minutes, and then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed with methanol, acetone, and isopropanol in sequence (5 minutes each time), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0057] HIL (hole injection layer): vacuum evaporation on the ITO anode in an evaporator 4,4 , , 4 , , 4-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) 200Å, forming a hole injection layer.

[0058] HTL (hole transport layer): NPB (i.e., N, N'-diphenyl-N, N'-(1-naphthyl)-1, 1'-biphenyl-4, 4'-diamine) was vacuum evaporated on the hole injection layer to form a hole transport layer.

[0059] Light-emitting layer: The light-emitting layer includes a first host material, a second host material and a guest dopant. After forming a hole injection layer and a hole transport layer, a light-emitting layer is formed on the HTL: the first host compound and the second host compound are introduced as hosts into two chambers of a vacuum vapor deposition device, respectively, and compound Z1 is introduced as a dopant into another chamber. The two host materials are evaporated at a rate of 1:1, and the dopant material is evaporated at different rates at the same time, and deposited with a doping amount of 3wt% based on the total amount of the host and the dopant to form a light-emitting layer with a thickness of 40nm on the second hole transport layer.

[0060] HBL (hole blocking layer): 100Åm of bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) was vacuum-deposited on the light-emitting layer to form a hole blocking layer.

[0061] ETL (electron transport layer): 8-hydroxyquinoline aluminum (Alq 3 ) 400Å, forming an electron transport layer.

[0062] EIL (Electron Injection Layer): LiF is vacuum evaporated on the electron transport layer 2 10Å, forming an electron injection layer.

[0063] Cathode: 1500Å of Al is evaporated on the electron injection layer to form a cathode, and an organic electroluminescent device can be obtained.

[0064] Referring to the organic electroluminescent devices and preparation methods thereof provided in Examples 1 and 2, another 52 organic electroluminescent compounds were selected to replace Examples 1 and 2 for evaporation of the main materials to prepare organic electroluminescent devices of the corresponding compounds.

[0065] The structure of the red light doping material (Z1) is as follows; .

[0066] The device manufacturing processes of device examples 1-30, comparative examples 1-7 and parallel examples 1-6 are exactly the same, and the same substrate materials and electrode materials are used. The film thickness of the electrode materials is also consistent. The difference is that the two main materials are different. The specific parameters are shown in Table 1.

[0067] Table 1 shows the parameters used in device examples 1-30, comparative examples 1-7, and parallel examples 1-6

[0068] The comparative example structure is as follows:

[0069] Performance testing: The driving voltage, luminous efficiency and life of the organic electroluminescent devices obtained in the above-mentioned comparative examples 1-7, parallel examples 1-6 and device examples 1-30 were characterized at a brightness of 6000 (nits). The test results are shown in Table 2 below.

[0070] Table 2

[0071] It can be seen from Table 2 that the driving voltage of the organic electroluminescent device provided by device example 1-30 of the present invention and parallel example 1-6 is 3.33~4.7V, which is significantly lower than the driving voltage of comparative example 1-7. At the same time, the luminous efficiency is higher than that of comparative example 1-7, and the lifespan is significantly improved compared with that of comparative example 1-7.

[0072] It can be seen that the organic electroluminescent device prepared using the organic electroluminescent compound provided by the present invention as the light-emitting layer material has a significantly lower driving voltage, and the luminous efficiency and life are significantly improved compared with the organic electroluminescent device prepared using the comparison compounds E-1, E-2, E-3, F-1, F-2, and F-3 as the light-emitting layer dual-host material.

[0073] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material containing a double host, characterized in that: The organic electroluminescent material containing two main bodies comprises a first main body material and a second main body material, and the mass ratio of the first main body material to the second main body material is 1:99-99:1; the first main body material has a structure shown in general formula 1, and the second main body material has a structure shown in general formula 2: ； in, R1, R2, R3, D1, D2, D3 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C6-C18 deuterated aryl, wherein the heteroatom is selected from oxygen, nitrogen or sulfur; L1 is selected from substituted or unsubstituted C6-C18 aryl; L2 and L3 are each independently selected from a connecting bond, a substituted or unsubstituted C6-C18 aryl group.

2. The organic electroluminescent material containing a double host according to claim 1, characterized in that: D1 and D2 are each independently selected from substituted or unsubstituted C6-C18 aryl groups; D3 is selected from substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C6-C36 deuterated aryl, substituted or unsubstituted C3-C30 heteroaryl; R1, R2, and R3 are each independently selected from the following structures and any combination thereof: 。 3. The organic electroluminescent material containing a double host according to claim 1 or 2, characterized in that: D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl; D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, triphenylene; D3 is selected from substituted or unsubstituted (C6-C30)aryl, substituted or unsubstituted (C3-C30)heteroaryl; L2 is a connecting bond, and L3 is a connecting bond or a phenyl group or a naphthyl group.

4. The organic electroluminescent material containing a double host according to claim 3, characterized in that: The heteroaryl group includes monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom, wherein the heteroatom includes but is not limited to O, S, and N; The substituted group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, 3-membered to 10-membered heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen or sulfur; or the substituted group in the "substituted or unsubstituted" is selected from the following structures: 。 5. The organic electroluminescent material containing a double host according to claim 1, characterized in that: The structure of the general formula 1 includes but is not limited to any one of the following compounds: 。 6. The organic electroluminescent material containing a double host according to claim 1, characterized in that: The structure of the general formula 2 includes but is not limited to any one of the following compounds: 。 7. A method for preparing an organic electroluminescent material containing a double host as claimed in claim 1, characterized in that: The preparation method of the general formula 1 specifically comprises the following steps: (1) Under nitrogen protection, weigh 1eq of reactant 1, 1-1.2eq of reactant 2, and 2-3eq of potassium carbonate into the reaction system, add THF, water, and 0.02-0.03eq of catalyst tetrakis(triphenylphosphine)palladium, reflux at 70-80°C for 24h under nitrogen protection, then cool to 25°C, add purified water, stir for 30min, stand for stratification, separate the layers, and perform column chromatography to obtain the compound R-1 shown; (2) Under nitrogen protection, weigh 1 eq R-1, add dichloromethane and 5 eq FeCl3, stir and react at room temperature for 0.5 h, then add methanol to separate the organic layer, spin dry, and perform column chromatography to obtain the compound R-2 shown; (3) Under nitrogen protection, weigh 1 eq of compound R-2, 1-1.2 eq of reactant 3, 2-3 eq of sodium tert-butoxide, add toluene, 0.02-0.03 eq of catalyst tris(dibenzylideneacetone)palladium and 0.04-0.06 eq of tri-tert-butylphosphine, reflux at 90-120°C for 24 h under nitrogen protection, then cool to 25°C, add purified water, stir for 30 min, stand for stratification, separate the layers, and perform column chromatography to obtain the compound R-3 shown; (4) Under nitrogen protection, weigh 1 eq of compound R-3, 1-1.2 eq of reactant 4, 2-3 eq of sodium tert-butoxide, add toluene, 0.02-0.03 eq of catalyst tris(dibenzylideneacetone)palladium and 0.04-0.06 eq of tri-tert-butylphosphine, reflux at 90-120°C for 24 h under nitrogen protection, then cool to 25°C, add purified water, stir for 30 min, let stand for stratification, separate the layers, and perform column chromatography to obtain the compound R-4 shown; (5) Under nitrogen protection, weigh 1 eq of compound R-4, 1-1.2 eq of reactant 5, and 2-3 eq of sodium tert-butoxide into the reaction system, add toluene, 0.02-0.03 eq of catalyst tris(dibenzylideneacetone)palladium and 0.04-0.06 eq of tri-tert-butylphosphine, reflux at 90-120°C for 24 h under nitrogen protection, then cool to 25°C, add purified water, stir for 30 min, let stand for stratification, separate the layers, and perform column chromatography to obtain the compound represented by formula 1; The specific synthetic route is as follows: ； The preparation method of the general formula 2 specifically comprises the following steps: (1) Under nitrogen protection, weigh 1eq of reactant 1, 1-1.2eq of reactant 2, and 3-4eq of potassium carbonate into the reaction system, add toluene, ethanol, water and 0.05-0.08eq of catalyst tetrakis(triphenylphosphine)palladium, reflux at 90°C for 24h under nitrogen protection, then cool to 25°C, filter, and perform solid column chromatography to obtain the compound H-1 shown; (2) Under nitrogen protection, weigh 1eq H-1, 1-1.2eq reactant 2-1, 3-4eq potassium carbonate into the reaction system, add toluene, ethanol, water and 0.05-0.08eq catalyst tetrakis(triphenylphosphine)palladium, reflux at 90-100°C for 24h under nitrogen protection, then cool to 25°C, filter, and perform solid column chromatography to obtain the compound H-2 shown; (3) Under nitrogen protection, weigh 1 eq H-2, 1-1.2 eq reactant 2-2, and 3-4 eq potassium carbonate into the reaction system, add toluene, ethanol, water and 0.05-0.08 eq catalyst tetrakis(triphenylphosphine)palladium, reflux at 90-100°C for 24 h under nitrogen protection, then cool to 25°C, filter, and perform solid column chromatography to obtain compound H as shown in general formula 2; The specific synthetic route is as follows: 。 8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the organic electroluminescent material containing a double host as claimed in claim 1.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; and the organic electroluminescent material layer comprises a light-emitting layer; the light-emitting layer comprises a doping material and the organic electroluminescent material containing a double host.

10. The organic electroluminescent device according to claim 9, characterized in that: The mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1-99):(99-1).

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