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

Abstract

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

Description

Technical Field

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

[0002] Organic light-emitting devices (OLEDs) can be used to manufacture new display products and new lighting products, and are gradually replacing existing liquid crystal displays and fluorescent lighting, with a very broad market application prospect. The structure of an OLED is like a sandwich, which includes electrode material layers and organic functional materials sandwiched between different electrode layers. Depending on the application, these functional materials are stacked together to form an OLED.

[0003] Currently, OLED display technology has been applied in fields such as smartphones and tablets. Expanding into large-size applications such as televisions is the next goal. However, compared with the requirements of actual product applications, the performance of OLED, such as luminous efficiency and lifespan, still needs to be further improved.

[0004] Improving the efficiency of OLEDs is achieved through host-guest doping in the emissive layer. This is because the radiative transitions of triplet excitons in most organic molecules are forbidden, contributing little to electroluminescence. 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, thus significantly improving the efficiency of organic light-emitting devices. However, triplet-triplet annihilation (TTA) occurs during the transfer process, resulting in energy loss and causing an efficiency roll-off in organic light-emitting devices.

[0005] Currently, the poor performance of organic electroluminescent devices remains a critical technical problem that urgently needs to be solved in their use. For example, there are issues such as excessively high driving voltage, low luminous efficiency, or short lifespan, all of which affect the application areas of organic electroluminescent devices.

[0006] Therefore, how to develop a long-life, low-driving-voltage dual-host organic electroluminescent material and organic electroluminescent device is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a host material, a dual-host organic electroluminescent material containing the host material, and an organic electroluminescent device. When the dual-host organic electroluminescent material of the present invention is applied to a specific light-emitting device, it has low driving voltage, high luminous efficiency, and long service life.

[0008] It should be noted that the organic electroluminescent device with a dual-host structure provided by the present invention can disperse triplet excitons on two hosts by using the dual host material, which can reduce triplet-triplet annihilation (TTA). When the two hosts 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 lifespan of the device.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The first technical objective of this invention is to provide a main material having the structure shown in general formulas 1-1 and 1-2:

[0011]

[0012] in:

[0013] R1, R2, and R3 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.

[0014] L1 is selected from substituted or unsubstituted aryl groups of C6-C24.

[0015] Furthermore,

[0016] L1 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, and terphenyl;

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

[0018]

[0019] In the technical solution of this invention, the main material specifically has the following structure, but is not limited to the following structure:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] The second technical objective of this invention is to provide a dual-host organic electroluminescent material, 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 is the host material described above, having the structure shown in general formulas 1-1 and 1-2; the second host material has the structure shown in general formula 2.

[0040]

[0041] in:

[0042] D1 and D2 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.

[0043] D3 is selected from substituted or unsubstituted (C6-C36) aryl, substituted or unsubstituted (C6-C36) deuterated aryl, substituted or unsubstituted (C3-C30) heteroaryl, wherein the heteroatom is selected from oxygen, nitrogen or sulfur;

[0044] L2 and L3 are selected from aryl groups that are linked by a linker, (C6-C18) substituted or unsubstituted.

[0045] Furthermore,

[0046] D1 and D2 are each independently selected from (C6-C18) substituted or unsubstituted aryl groups.

[0047] Furthermore,

[0048] D1 is selected from substituted or unsubstituted phenyl, biphenyl, and terphenyl;

[0049] D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, and benzophenanthryl;

[0050] D3 is selected from substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (C3-C30) heteroaryl;

[0051] L2 is a linking bond, and L3 is a linking bond or a phenyl or naphthyl group.

[0052] 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.

[0053] Optionally, the heteroaryl group includes a monocyclic aromatic group and a polycyclic aromatic ring system with at least one heteroatom, and the heteroatom includes, but is not limited to, O, S, and N.

[0054] Furthermore, the substituted group in the term "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterated C1-C10 alkyl, C3-C20 cycloalkyl, and 3-20 membered heterocyclic alkyl, wherein the heteroatom is selected from oxygen, nitrogen, and sulfur; the substituted group in the term "substituted or unsubstituted" includes, but is not limited to, the following structures:

[0055]

[0056] In the technical solution of this invention, the second main material is selected from any one of the following compounds:

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] The third technical objective of this invention is to provide a method for preparing the aforementioned dual-host organic electroluminescent material.

[0077] The preparation method of general formula 1-1 specifically includes the following steps:

[0078] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), potassium carbonate (2-3 eq) were weighed and placed into the reaction system. THF, water, and catalyst tetra(triphenylphosphine)palladium (0.02-0.03 eq) were added. The mixture was refluxed at 70°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-1.

[0079] (2) Under nitrogen protection, weigh R-1 (1 eq), add dichloromethane and FeCl3 (5 eq), stir for 0.5 h, then add methanol to separate the organic layer, evaporate to dryness, and column chromatography to obtain compound R-2.

[0080] (3) Under nitrogen protection, compound R-2 (1 eq), reactant 3 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-3.

[0081] (4) Under nitrogen protection, compound R-3 (1 eq), reactant 4 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-4.

[0082] (5) Under nitrogen protection, compound R-4 (1 eq), reactant 5 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain general formula 1-1.

[0083] The specific synthesis route is as follows:

[0084]

[0085]

[0086] Furthermore, the preparation method of general formula 1-2 specifically includes the following steps:

[0087] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), potassium carbonate (2-3 eq) were weighed and placed into the reaction system. THF, water, and catalyst tetra(triphenylphosphine)palladium (0.02-0.03 eq) were added. The mixture was refluxed at 70°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-1.

[0088] (2) Under nitrogen protection, weigh R-1 (1 eq), add dichloromethane and FeCl3 (5 eq), stir for 0.5 h, then add methanol to separate the organic layer, evaporate to dryness, and column chromatography to obtain compound R-2.

[0089] (3) Under nitrogen protection, compound R-2 (1 eq), reactant 3 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-3.

[0090] (4) Under nitrogen protection, compound R-3 (1 eq), reactant 4 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R-4.

[0091] (5) Under nitrogen protection, compound R-4 (1 eq), reactant 5 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and added to the reaction system. Toluene, catalyst tris(dibenzylacetone) bispalladium (0.02-0.03 eq) and tritert-butylphosphine (0.04-0.06 eq) were added. The mixture was refluxed at 90-120℃ for 24 h under nitrogen protection, then cooled to 25℃, purified water was added, and the mixture was stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain general formula 1-2.

[0092] The specific synthesis route is as follows:

[0093]

[0094]

[0095] Furthermore, the preparation method of general formula 2 specifically includes the following steps:

[0096] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), 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 °C for 24 h under nitrogen protection, then cooled to 25 °C, filtered, and subjected to solid column chromatography to obtain compound H-1.

[0097] (2) Under nitrogen protection, weigh H-1 (1 eq), reactant 2-1 (1-1.2 eq), potassium carbonate (3-4 eq) and add them to the reaction system. Add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.05-0.08 eq). Reflux at 90-100℃ for 24 h under nitrogen protection, then cool to 25℃, filter, and perform solid column chromatography to obtain compound H-2.

[0098] (3) Under nitrogen protection, weigh H-2 (1 eq), reactant 2-2 (1-1.2 eq), potassium carbonate (3-4 eq) and add them to the reaction system. Add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.05-0.08 eq). Reflux at 90-100℃ for 24 h under nitrogen protection, then cool to 25℃, filter, and perform solid column chromatography to obtain compound H (general formula 2).

[0099] The specific synthesis route is as follows:

[0100]

[0101] The fourth technical objective of this invention is to provide an application of a dual-host organic electroluminescent material in the fabrication of organic electroluminescent devices.

[0102] 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 doped material and a dual-host organic electroluminescent material as described above;

[0103] The mass ratio of the dual-host organic electroluminescent material to the doped material is (1-99):(99-1).

[0104] 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 as shown in Formula 1-1 and Formula 1-2, and a second host material as shown in Formula 2.

[0105] 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.

[0106] 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.

[0107] Hole injection layer materials are materials that receive 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.

[0108] 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.

[0109] 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.

[0110] The main material of the light-emitting layer is selected from the structure of this invention.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] Depending on the materials used, the above-mentioned organic electroluminescent devices can be top-emitting, bottom-emitting, or bilaterally emitting.

[0115] 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.

[0116] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0117] The organic electroluminescent material provided by this invention is a dual-host organic compound. When used in organic electroluminescent devices, it can reduce triplet-triplet annihilation (TTA), thereby reducing the driving voltage of the organic electroluminescent device while improving the device's efficiency and lifespan. Attached Figure Description

[0118] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0119] Figure 1 This is the R002 nuclear magnetic resonance hydrogen spectrum of the present invention. Detailed Implementation

[0120] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0121] This invention discloses a host material and a method for preparing a dual-host organic electroluminescent material containing the host material.

[0122] 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.

[0123] Example 1: Preparation of compound R002

[0124]

[0125] Under nitrogen protection, reactant 1 (CAS No.: 2138490-84-1) (140.91 mmol), reactant 2 (CAS No.: 4688-76-0) (140.91 mmol), and potassium carbonate (422.73 mmol) were weighed and added to the reaction system. 1000 mL of tetrahydrofuran, 500 mL of purified water, and tetra(triphenylphosphine)palladium catalyst (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 stirred for 30 min. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain compound R002-1 (test value: 355.76 g, 36.6 g, yield: 73.2%).

[0126]

[0127] Under nitrogen protection, 21.5 mmol of R002-1 was weighed, and 860 mL of dichloromethane and 107.5 mmol of FeCl3 were added. The mixture was stirred for 0.5 h, and then 430 mL of methanol was added to separate the organic layer. The mixture was evaporated to dryness and subjected to column chromatography to obtain compound R002-2 (test value: 353.91 g, 6.52 g, yield: 86%).

[0128]

[0129] Under nitrogen protection, compound R002-2 (18.4 mmol), reactant 3 (18.4 mmol), and sodium tert-butoxide (36.8 mmol) were weighed and added to the reaction system. Toluene (100 mL), catalyst tris(dibenzylacetone) bispalladium (0.368 mmol) and tri-tert-butylphosphine (0.736 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, and purified water (100 mL) was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by column chromatography to obtain compound R002-3 (test value: 410.2 g, 5.6 g, yield: 74.3%).

[0130]

[0131] Under nitrogen protection, compound R002-3 (17.6 mmol), reactant 4 (17.6 mmol), and sodium tert-butoxide (35.2 mmol) were weighed and added to the reaction system. Toluene (100 mL), catalyst tris(dibenzylacetone) bispalladium (0.352 mmol) and tri-tert-butylphosphine (0.704 mmol) were added. The mixture was refluxed at 100 °C for 24 h under nitrogen protection, then cooled to 25 °C, and purified water (100 mL) was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by column chromatography to obtain compound R002-4 (test value: 565.51 g, 7.57 g, yield: 76.2%).

[0132]

[0133] Under nitrogen protection, compound R002-4 (13.3 mmol), reactant 5 (13.3 mmol), and sodium tert-butoxide (26.6 mmol) were weighed and added to the reaction system. Toluene (80 mL), catalyst tris(dibenzylacetone) bispalladium (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, then cooled to 25 °C, and purified water (80 mL) was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated and subjected to column chromatography to obtain compound R002 (test value: 652.80, 6.57 g, yield: 75.77%) with an HPLC purity greater than 99%.

[0134] The proton NMR spectrum of R002 is shown below. Figure 1 .

[0135] Example 2: Preparation of compound H004

[0136]

[0137] Under nitrogen protection, reactant 1 (CAS No.: 108-77-0) (271.14 mmol), reactant 2 (CAS No.: 98-80-6) (271.14 mmol), and potassium carbonate (813.43 mol) were weighed and added to the reaction system. 500 mL of toluene, 250 mL of ethanol, 250 mL of water, and tetrakis(triphenylphosphine)palladium catalyst (13.56 mmol) 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 compound H001-1 (measured value: 225.49 g, 39.4 g, yield 64.7%).

[0138]

[0139] Under nitrogen protection, H001-1 (132.71 mmol), reactant 2-1 (CAS No.: 98-80-6) (132.71 mmol), and potassium carbonate (398.12 mol) were weighed and added to the reaction system. 500 mL of toluene, 250 mL of ethanol, 250 mL of water, and tetrakis(triphenylphosphine)palladium catalyst (13.56 mmol) 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 compound H001-2 (test value: 267.56, 23 g, yield 64.5%).

[0140]

[0141] Under nitrogen protection, H001-2 (74.71 mmol), reactant 2-2 (CAS No.: 374538-04-2) (74.71 mmol), and potassium carbonate (224.12 mol) were weighed and added to the reaction system. 200 mL of toluene, 100 mL of ethanol, 100 mL of water, and tetrakis(triphenylphosphine)palladium catalyst (3.74 mmol) 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 compound H004 (test value: 391.50, 15.3 g, yield 52.3%).

[0142] Test data for other embodiments are shown in Table 1.

[0143] Table 1

[0144]

[0145]

[0146] Example 1: Fabrication of an organic electroluminescent device:

[0147] Organic electroluminescent devices were prepared using compound R002 prepared in Example 1 and compound H004 prepared in Example 2. Specifically, the preparation method of the organic electroluminescent device is as follows:

[0148] ITO anode: The coating thickness is... The ITO (indium tin oxide) glass substrate was cleaned twice with distilled water, ultrasonically washed for 30 minutes, then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed sequentially with methanol, acetone, and isopropanol (5 minutes each time), dried, and then transferred to a plasma cleaner for 5 minutes to obtain the ITO anode.

[0149] HIL (Hole Injection Layer): A 4,4-layer HIL is vacuum-deposited onto an ITO anode in a vapor deposition machine. ， 4 ， 4-Tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) A cavity injection layer is formed.

[0150] HTL (Hole Transport Layer): NPB (i.e., N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) is vacuum-deposited onto the hole injection layer. A hole transport layer is formed.

[0151] Emitting layer: The emitting layer comprises a first host material, a second host material, and a guest dopant. After forming a hole injection layer and a hole transport layer, the emitting layer is formed on the HTL: the first host compound and the second host compound are introduced as hosts into two chambers of a vacuum vapor deposition apparatus, and compound Z1 is introduced as a dopant into another chamber; the two host materials are evaporated at a 1:1 ratio, and the dopant material is evaporated simultaneously at different rates, and a doping amount of 3 wt% based on the total amount of host and dopant is deposited to form an emitting layer with a thickness of 40 nm.

[0152] HBL (Hole Blocking Layer): Vacuum-deposited onto the light-emitting layer. A thick layer of bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) forms a hole-blocking layer.

[0153] ETL (Electron Transport Layer): Vacuum-deposited onto a hole-blocking layer. A thick layer of 8-hydroxyquinoline aluminum (Alq3) forms an electron transport layer.

[0154] EIL (Electron Injection Layer): Vacuum evaporation on the electron transport layer A thick layer of LiF2 is used to form an electron injection layer.

[0155] Cathode: deposited on the electron injection layer By forming a cathode with a thickness of Al, an organic electroluminescent device can be obtained.

[0156] Device Examples 2-30:

[0157] Referring to the organic electroluminescent device and its preparation method provided in Device Example 1, organic electroluminescent compounds from Table 2 were selected to replace the first host compound and the second host compound for vapor deposition of the host material, respectively, to prepare organic electroluminescent devices of the corresponding compounds.

[0158] The structure of the red-light-doped material (Z1) is as follows:

[0159]

[0160] Device Example 1-31, Comparative Example 1-7 and Parallel Example 1-6

[0161] The device fabrication processes of Device Examples 1-31, Comparative Examples 1-7 and Parallel Examples 1-6 are exactly the same, and the same substrate material and electrode material are used. The film thickness of the electrode material is also consistent. The difference is that the two main materials are different. The corresponding first main compound and second main compound in Table 2 are selected respectively. The specific parameters are shown in the table below.

[0162] Table 2 shows the parameters used in Device Examples 1-31, Comparative Examples 1-7, and Parallel Examples 1-6.

[0163]

[0164]

[0165] The comparative example structure is as follows:

[0166]

[0167] Performance testing: The driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained in Comparative Examples 1-7, Parallel Examples 1-6, and Device Examples 1-31 were characterized at a brightness of 5000 nits. The test results are shown in Table 3 below.

[0168] Table 3

[0169]

[0170] As can be seen from Table 3, the driving voltage of the organic electroluminescent device provided by Device Examples 1-31 of the present invention is 2.89V to 3.28V, which is significantly lower than the driving voltage of Comparative Examples 1-7 and Parallel Examples 1-6. At the same time, the luminous efficiency is higher than that of Comparative Examples 1-7, and the lifetime is significantly improved compared with Comparative Examples 1-7.

[0171] Therefore, it can be seen that, compared with organic electroluminescent devices prepared using the organic electroluminescent compounds provided in this invention as the light-emitting layer material, the driving voltage of the organic electroluminescent device prepared using the comparative compounds E-1, E-2, E-3, F-1, F-2, and F-3 as the dual host materials of the light-emitting layer is significantly reduced, and the luminous efficiency and lifetime are significantly improved.

[0172] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A main material, characterized in that, The main material specifically has one of the following structures: 。 2. A dual-host organic electroluminescent material, characterized in that, The dual-host organic electroluminescent material comprises 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 is the host material as described in claim 1, and the second host material has the structure shown in general formula 2: ； in: D1 and D2 are each independently selected from substituted or unsubstituted C6-C42 aryl and substituted or unsubstituted C6-C30 heteroaryl groups; D3 is selected from substituted or unsubstituted C6-C36 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups, wherein the heteroatom is selected from oxygen, nitrogen or sulfur; L2 and L3 are selected from the linking bond, substituted or unsubstituted C6-C18 aryl groups; The term "substituted or unsubstituted" means that the group is not substituted, or is substituted by one or more substituents; the term "substituted" means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent, and there is no restriction on the position of substitution, as long as the position is where the hydrogen atom is substituted, that is, the position where the substituent is substituted, and when two or more substituents are substituted, the two or more substituents are the same as or different from each other. The substituted group in "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterated C1-C10 alkyl, C3-C20 cycloalkyl, 3-20 heterocyclic alkyl, and its heteroatom is selected from oxygen, nitrogen, and sulfur.

3. The dual-host organic electroluminescent material according to claim 2, characterized in that, D1 and D2 are each independently selected from substituted or unsubstituted C6-C18 aryl groups.

4. The dual-host organic electroluminescent material according to claim 2, characterized in that, D1 is selected from substituted or unsubstituted phenyl, biphenyl, and terphenyl; D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, and benzophenanthryl; D3 is selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; L2 is a linking bond, and L3 is a linking bond or a phenyl or naphthyl group.

5. A dual-host organic electroluminescent material, characterized in that, The dual-host organic electroluminescent material comprises 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 is as described in claim 1, and the second host material is selected from any one of the following structures: 。 6. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises the dual-host organic electroluminescent material as described in claim 2.

7. The organic electroluminescent device according to claim 6, 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, which includes a doped material and the dual-host organic electroluminescent material. The mass ratio of the dual-host organic electroluminescent material to the doped material is (1~99):(99~1).

Images