Organic Electroluminescent Material Containing Dual Hosts, Preparation Method Thereof, and Organic Electroluminescent Device

Abstract

The present invention belongs to the field of organic electroluminescent materials, and discloses an organic electroluminescent material containing a dual host, a preparation method thereof, and an organic electroluminescent device. The organic electroluminescent material containing a dual host includes a first host material and a second host material. The first host material is a compound having a structure represented by general formula (1), and the second host material is a compound having a structure represented by general formula (2). By using the dual host material, triplet excitons are dispersed on two hosts, reducing triplet-triplet annihilation. While reducing the driving voltage of the organic electroluminescent device, the luminous efficiency and service life of the device can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of organic electroluminescent materials, and particularly relates to an organic electroluminescent material containing a dual host, a preparation method, and an organic electroluminescent device. Background Art

[0002] Organic electroluminescent devices (OLEDs) can be used to manufacture new display products and new lighting products. The market application prospect is very broad. Currently, OLED display technology has been applied in fields such as smart phones and tablet computers. However, compared with the actual product application requirements, the performance of OLEDs, such as luminous efficiency and service life, still needs to be further improved.

[0003] The OLED structure includes electrode film layers and organic functional materials sandwiched between different electrode film layers. As a current device, when a voltage is applied to the two electrodes of the OLED, positive and negative charges in the organic layer functional material film layer are separated by the action of an 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 the contribution to electroluminescence is very small, by doping organic metal complexes such as platinum, iridium, and osmium, the triplet excitons of organic molecules can be transferred to the triplet state of the metal complex, thereby improving the efficiency of the organic light-emitting device. Therefore, the efficiency of OLEDs can be improved by doping the host and guest in the light-emitting layer. However, triplet-triplet annihilation (TTA) occurs during the transfer process of triplet excitons, resulting in energy loss and causing efficiency roll-off of the organic light-emitting device.

[0004] Currently, 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 too high driving voltage, too low luminous efficiency, or short service life, which all affect the application fields of organic electroluminescent devices.

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

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

[0007] It should be noted that the present invention provides an organic electroluminescent device with a dual-host structure. By using this 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, while reducing the driving voltage of the organic electroluminescent device, the efficiency and lifespan of the device can be improved.

[0008] To achieve the above object, the following technical solutions are adopted:

[0009] An organic electroluminescent material containing a dual host, the organic electroluminescent material containing a dual host includes a first host material and a second host material, and 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:

[0010] ;

[0011] Wherein,

[0012] R1, R2, R3, D1, D2, D3 are each independently selected from a substituted or unsubstituted C6 - C42 aryl group, a substituted or unsubstituted C6 - C30 heteroaryl group, a substituted or unsubstituted C6 - C18 deuterated aryl group, wherein the heteroatom is selected from oxygen, nitrogen or sulfur;

[0013] L1 is selected from a substituted or unsubstituted C6 - C18 aryl group;

[0014] L2 and L3 are each independently selected from a linking bond, a substituted or unsubstituted C6 - C18 aryl group.

[0015] Furthermore, D1 and D2 are each independently selected from a substituted or unsubstituted C6 - C18 aryl group;

[0016] D3 is selected from a substituted or unsubstituted C6 - C36 aryl group, a substituted or unsubstituted C6 - C36 deuterated aryl group, a substituted or unsubstituted C3 - C30 heteroaryl group;

[0017] R1, R2, R3 are each independently selected from the following structures and any combination thereof:

[0018] 。

[0019] Even further, D1 is selected from a substituted or unsubstituted phenyl group, biphenyl group, terphenyl group;

[0020] D2 is selected from a substituted or unsubstituted phenyl group, naphthyl group, biphenyl group, terphenyl group, benzophenanthryl group;

[0021] D3 is selected from substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (C3-C30) heteroaryl;

[0022] L2 is a linking bond, and L3 is a linking bond, phenyl or naphthyl.

[0023] In the above technical solution, the "substituted or unsubstituted" means that the group may not be substituted or may be substituted by one or more substituents. The "substitution" means that a hydrogen atom bonded to a carbon atom of the compound becomes another substituent, and there is no restriction on the substitution position 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 or different from each other.

[0024] Moreover, the heteroaryl includes a monocyclic aromatic group and a polycyclic aromatic ring system containing at least one heteroatom, and the heteroatom includes but is not limited to O, S, N.

[0025] 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- 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:

[0026] .

[0027] Further, the general formula 1 specifically has the following structure, but is not limited thereto: 。

[0028] Furthermore, the general formula 2 is selected from any one of the following compounds:

[0029] 。

[0030] The present invention also provides a preparation method of an organic electroluminescent material containing a dual host, specifically including the preparation methods of the first host material and the second host material, as follows:

[0031] 1. The preparation method of the general formula 1 specifically includes the following steps:

[0032] (1) Under a nitrogen protection system, weigh reactant 1 (1 eq), reactant 2 (1 - 1.2 eq), and potassium carbonate (2 - 3 eq) and put them into the reaction system. Add THF, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.02 - 0.03 eq). Reflux at 70 - 80 °C for 24 h under nitrogen protection, then cool to 25 °C, add pure water, stir for 30 min, then let it stand for liquid separation, separate the liquid, and perform column chromatography to obtain the compound R-1 shown;

[0033] (2) Under a nitrogen protection system, weigh R-1 (1 eq), add dichloromethane and FeCl3 (5 eq), 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;

[0034] (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;

[0035] (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;

[0036] (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;

[0037] The specific synthetic route is as follows:

[0038] .

[0039] 2. The preparation method of the general formula 2 specifically comprises the following steps:

[0040] (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;

[0041] (2) Under a nitrogen protection system, weigh H-1 (1 eq), reactant 2-1 (1 - 1.2 eq), and potassium carbonate (3 - 4 eq) and place them into the reaction system. Add toluene, ethanol, water, and the 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 by suction, and perform solid column chromatography to obtain the shown compound H-2;

[0042] (3) Under a nitrogen protection system, weigh H-2 (1 eq), reactant 2-2 (1 - 1.2 eq), and potassium carbonate (3 - 4 eq) and place them into the reaction system. Add toluene, ethanol, water, and the 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 by suction, and perform solid column chromatography to obtain the shown compound H (general formula 2);

[0043] The specific synthesis route is as follows:

[0044] .

[0045] Moreover, the present invention also claims the application of the above-mentioned organic electroluminescent material containing a dual host in the preparation of an organic electroluminescent device.

[0046] 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 a doping material and the above-mentioned organic electroluminescent material containing a dual host;

[0047] Wherein, the mass ratio of the organic electroluminescent material containing a dual host to the doping material is (1~99):(99~1).

[0048] More specifically, the organic electroluminescent device includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode. The light-emitting layer includes a first host material of general formula 1 and a second host material shown by general formula 2.

[0049] As the anode material, materials with a large work function are usually preferably used to enable smooth 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 their alloys; 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-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but not limited thereto.

[0050] As a cathode material, a material with a small work function is usually preferably used to enable electrons to 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 LiO2 / Al; and so on, but not limited thereto.

[0051] 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 materials include metal porphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, and conductive polymers based on polyaniline and polythiophene, etc.

[0052] 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 materials include arylamine-based organic materials, conductive polymers, block copolymers having both a conjugated part and a non-conjugated part, etc., but not limited thereto.

[0053] An electron blocking layer can be provided between the hole transport layer and the light-emitting layer. As the electron blocking layer, materials known in the art can be used, such as arylamine-based organic materials.

[0054] The host material of the light-emitting layer is selected from the structure of the present invention.

[0055] A hole blocking layer can be provided between the electron transport layer and the light-emitting layer, and materials known in the art can be used, such as triazine-based compounds.

[0056] The electron transport layer can play a role in promoting electron transport. The electron transport material is advantageously a material that receives electrons from the cathode and transports the electrons to the light-emitting layer and has a high electron mobility. It includes: Al complexes of 8-hydroxyquinoline; complexes containing Alq3; organic radical compounds; hydroxyflavone-metal complexes, etc., but not limited thereto. The thickness of the electron transport layer can be 1 nm to 50 nm. The electron transport layer with a thickness of 1 nm or more has the advantage of preventing the decline of electron transport characteristics, and the thickness of 50 nm or less has the advantage of preventing the increase of the driving voltage caused by the too thick electron transport layer.

[0057] The electron injection layer can play a role in promoting electron injection, and the electron injection material preferably has the ability to transport electrons, has the effect of injecting electrons from the cathode, has an excellent electron injection effect on the light-emitting layer or the light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and in addition, has excellent thin film forming ability. Specific examples thereof include fluorenone, anthraquinodimethane, biphenylquinone, thiopyran dioxide, oxazole, dioxazole, triazole, imidazole, perylene tetracarboxylic acid, fluoreneylidene methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but are not limited thereto.

[0058] According to the materials used, the above-mentioned organic electroluminescent device can be a top-emitting type, a bottom-emitting type or a double-sided emitting type.

[0059] In addition, the organic electroluminescent device described in the present invention can be used in organic solar cells, electronic papers, organic photoreceptors or organic thin film transistors.

[0060] From the above technical solutions, the present invention has the following beneficial effects:

[0061] 1) When the fusion position of phenanthrene and furan in the first host material is changed, its molecular structure changes, having a high T1 energy level, preventing the energy back transfer from the guest to the host, so that it can have high device efficiency and long-life host characteristics under the condition of increasing the driving temperature.

[0062] 2) While reducing the driving voltage of the organic electroluminescent device, it can improve the efficiency and life of the device, having good application effects and industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0064] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum diagram of compound R010 provided in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0065] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention and the relevant drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0066] The invention specifically discloses an organic electroluminescent material containing double hosts, a preparation method and an organic electroluminescent device.

[0067] 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.

[0068] Example 1: Preparation of Compound R010

[0069]

[0070] 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%).

[0071]

[0072] Under nitrogen protection, R010-1 (23 mmol) was weighed, dichloromethane (920 ml) and FeCl3 (115 mmol) were added, and the reaction was stirred at room temperature for 0.5 h, and then methanol (460 ml) was added to separate the organic layer, spin-dried, and column chromatography was performed to obtain the compound R010-2 (test value: 353.01, 7.16 g, yield: 88.2%).

[0073]

[0074] 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%).

[0075]

[0076] 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%).

[0077]

[0078] 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%.

[0079] Example 2: Preparation of Compound H004

[0080] ;

[0081] 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).

[0082] ;

[0083] Under a nitrogen protection system, weigh H004-1 (132.71 mmol), reactant 2-1 (cas: 98-80-6) (132.71 mmol), and potassium carbonate (398.12 mol) and place them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, perform suction filtration, and conduct solid column chromatography to obtain the shown compound H004-2 (test value: 267.56, 23 g, yield 64.5%).

[0084]

[0085] Under a nitrogen protection system, weigh H004-2 (74.71 mmol), reactant 2-2 (cas: 374538-04-2) (74.71 mmol), and potassium carbonate (224.12 mol) and place them into the reaction system. Add 200 ml of toluene, 100 ml of ethanol, 100 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (3.74 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, perform suction filtration, and conduct solid column chromatography to obtain the shown compound H004 (test value: 391.52, 16 g, yield 52.3%).

[0086] It should be noted that other compounds of the present invention can be obtained by referring to the preparation methods of Example 1 and Example 2 listed above, so they will not be elaborated here.

[0087] Use the compound R010 prepared in Example 1 and the compound H004 prepared in Example 2 to prepare an organic electroluminescent device. Specifically, the preparation method of this organic electroluminescent device is as follows:

[0088] ITO anode: Wash an ITO (indium tin oxide) glass substrate with a coating thickness of 1500 Å twice in distilled water, ultrasonically wash for 30 min, then wash repeatedly twice with distilled water and ultrasonically wash for 10 min. After the washing is completed, ultrasonically wash with methanol, acetone, and isopropanol in sequence (each washing for 5 min), dry, and then transfer it into a plasma cleaner for washing for 5 min to obtain the ITO anode.

[0089] HIL (hole injection layer): In an evaporation machine, vacuum evaporate 4,4 , ,4 , ,4-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine (m-MTDATA) with a thickness of 200 Å on the ITO anode to form a hole injection layer.

[0090] HTL (Hole Transport Layer): On the hole injection layer, NPB (i.e., N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) is vacuum-evaporated at 400 Å to form the hole transport layer.

[0091] Emitting layer: The emitting layer includes a first host material, a second host material, and a guest dopant. After forming the hole injection layer and the hole transport layer, the 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 apparatus respectively, and the 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 simultaneously at different rates for deposition at a doping amount of 3 wt% based on the total amount of the host and the dopant, so as to form an emitting layer with a thickness of 40 nm on the second hole transport layer.

[0092] HBL (Hole Blocking Layer): On the emitting layer, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (BAlq) is vacuum-evaporated at 100 Åm to form the hole blocking layer.

[0093] ETL (Electron Transport Layer): On the hole blocking layer, aluminum tris(8-hydroxyquinoline) (Alq3) is vacuum-evaporated at 400 Å to form the electron transport layer.

[0094] EIL (Electron Injection Layer): On the electron transport layer, LiF is vacuum-evaporated at 210 Å to form the electron injection layer.

[0095] Cathode: On the electron injection layer, Al is evaporated at 1500 Å to form the cathode, and thus an organic electroluminescent device can be obtained.

[0096] Referring to the organic electroluminescent devices and their preparation methods provided in Example 1 and Example 2, another 52 organic electroluminescent compounds are respectively selected to replace those in Example 1 and Example 2 for the evaporation of the host materials, and organic electroluminescent devices corresponding to the compounds are prepared.

[0097] The structure of the red light dopant material (Z1) is as follows;

[0098] 。

[0099] The device fabrication 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, and the film thicknesses of the electrode materials are also kept consistent. The differences are as follows: The two host materials are different, and the specific parameters are shown in Table 1.

[0100] Table 1 shows the parameters used in Device Examples 1-30, Comparative Examples 1-7, and Parallel Examples 1-6

[0101]

[0102] The comparative example structure is as follows:

[0103]

[0104] Performance detection: At a brightness of 6000 (nits), the driving voltage, luminous efficiency, and lifespan of the organic electroluminescent devices obtained from the above Comparative Examples 1-7, Parallel Examples 1-6, and Device Examples 1-30 were characterized, and the test results are shown in Table 2 below.

[0105] Table 2

[0106]

[0107] As can be seen from Table 2, the driving voltages of the organic electroluminescent devices provided by Device Examples 1-30 of the present invention and Parallel Examples 1-6 are 3.33 - 4.7V, which are significantly lower than those of Comparative Examples 1-7. At the same time, the luminous efficiency is higher than that of Comparative Examples 1-7, and the lifespan is significantly improved compared to Comparative Examples 1-7.

[0108] It can be seen from this that compared with the organic electroluminescent devices prepared using comparative compounds E-1, E-2, E-3, F-1, F-2, and F-3 as the double host materials of the light-emitting layer, the organic electroluminescent devices prepared using the organic electroluminescent compounds provided by the present invention as the light-emitting layer materials have a significantly reduced driving voltage, and the luminous efficiency and lifespan are significantly improved.

[0109] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can 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 dual 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, and R3 are each independently selected from the following structures and any combination thereof: ； 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; 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; 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: 。 2. The organic electroluminescent material containing a dual host according to claim 1, characterized in that, L2 is a connecting bond, and L3 is a connecting bond or a phenyl group or a naphthyl group.

3. The organic electroluminescent material containing a dual host according to claim 2, characterized in that, The heteroaryl group includes a monocyclic aromatic group and a polycyclic aromatic ring system having at least one heteroatom, wherein the heteroatom is selected from O, S, and N.

4. The organic electroluminescent material containing a dual host according to claim 1, wherein, The structure of the general formula 1 is selected from any one of the following compounds: 。 5. The organic electroluminescent material containing a dual host according to claim 1, characterized in that, The structure of the general formula 2 is selected from any one of the following compounds: 0 。 6. 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: 。 7. 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.

8. The organic electroluminescent device according to claim 7, wherein 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.

9. The organic electroluminescent device according to claim 8, characterized in that, The mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1-99):(99-1).

Images