Organic electroluminescent compound, organic electroluminescent material containing double-host material and luminescent device

Abstract

The invention discloses an organic electroluminescent compound, an organic electroluminescent material containing a double-host material and a luminescent device.A first host compound and a second host compound which have specific structures are compounded, the electron injection transmission energy of the first host compound (formula 1) is high, the first host compound is connected with other groups through triazine, a steric hindrance effect exists, and the second host compound is connected with other groups through triazine; the approaching of deuterated indolocarbazole molecules can be inhibited; and triazine is connected with other groups, so that the electron injection and transmission capability to the light-emitting layer can be controlled at a relatively high level. The hole injection transport energy of the second host carbazole compound (formula 2) is high, and the hole injection transport property can be controlled at a high level by changing the bonding pattern of the carbazole ring and the type / number of substituents to the skeleton. The double-host material is applied to the light-emitting layer of the organic light-emitting device, so that the driving voltage can be reduced, the light-emitting efficiency of the organic light-emitting device is improved, and the service life is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic materials. Specifically, it particularly relates to an organic electroluminescent compound, an organic electroluminescent material containing a double host material, and a light-emitting device. Background Art

[0002] An organic electroluminescent device is a self-luminous device. Due to its characteristics such as low driving voltage, high resolution, high brightness, fast response time, and flexibility, it has received extensive attention in the panel display device industry.

[0003] Currently, organic electroluminescent device (OLED) display technology has been applied in fields such as smartphones and tablet computers, and will also expand to large-size application fields such as televisions. However, compared with the actual product application requirements, the performance such as luminous efficiency and service life of OLEDs still needs to be further improved.

[0004] The light-emitting material of an organic electroluminescent device (OLED) is the most important factor determining the luminous efficiency of the device, and can be classified into a host material and a dopant material in terms of function. The light-emitting material can be used by mixing the host and dopant materials in order to improve color purity, luminous efficiency, and stability. Generally, a device with excellent electroluminescence (EL) characteristics has a light-emitting layer structure formed by doping a dopant material into a host material. When using such a dopant / host material system as the light-emitting material, since the host material greatly affects the efficiency and life of the light-emitting device, the selection of the host material is very crucial and important.

[0005] Therefore, considering the EL characteristics required for medium and large-sized OLED panels, developing highly excellent light-emitting materials for organic electroluminescent devices to have high efficiency and long life characteristics has become the current research focus. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the present invention provides an organic electroluminescent compound, an organic electroluminescent material containing a double host material, and a light-emitting device, which have high luminous efficiency and long life characteristics by using a specific combination of compounds as the host material.

[0007] In order to solve the above problems, the present invention provides the following technical solutions:

[0008] An organic electroluminescent compound having a chemical structure represented by the general formula (1):

[0009]

[0010] Wherein, R 1 -R 4 Each independently selected from substituted or unsubstituted C6 -C 30 aryl of, C 6 -C 30 heteroaryl; the heteroatoms in the heteroaryl are selected from O, N or S;

[0011] All hydrogen atoms in the general formula (1) may be all unsubstituted by deuterium, all substituted by deuterium or partially substituted by deuterium;

[0012] The substituents of the "substituted" group are selected from deuterium, fluorine, cyano, C 1 -C 10 alkyl, C 1 -C 10 alkoxy, C 3 -C 10 cycloalkyl or C 6 -C 12 a combination of one or at least two of aryl.

[0013] According to an embodiment of the present invention, the R 1 -R 4 are independently selected from substituted or unsubstituted C 6 -C 18 aryl, substituted or unsubstituted C 6 -C 15 heteroaryl, and the heteroatoms in the heteroaryl are selected from O, N or S.

[0014] According to an embodiment of the present invention, the R 1 -R 4 is selected from the following groups, capable of connecting at any substitutable site, and the following groups may be further substituted by deuterium:

[0015]

[0016] According to an embodiment of the present invention, the compound of the structure shown in the general formula (1) is selected from any one of G1-1 to G1-240:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] The above are some specific structural forms of the organic electroluminescent compounds, but not limited to these chemical structures listed. All compounds with simple transformations of groups within the defined ranges based on the general formula shown in Formula (1) should be included.

[0033] On the other hand, the present invention also provides an organic electroluminescent material containing a double host material, the organic electroluminescent material comprising a first host material and a second host material, the first host material being a compound having the structure shown in the above general formula (1); the second host material being a compound having the structure shown in general formula (2):

[0034]

[0035] Wherein, Ar is selected from hydrogen, substituted or unsubstituted (C 6 -C 30 ) aryl, substituted or unsubstituted (C6-C30) heteroaryl;

[0036] L is selected from a linking bond, unsubstituted C 6 -C 18 aryl, substituted or unsubstituted C 6 -C 18 heteroaryl;

[0037] T 1 to T 8 are each independently selected from hydrogen, deuterium, substituted or unsubstituted (C 6 -C 30 ) aryl, substituted or unsubstituted (C 6 -C 30 ) heteroaryl, substituted or unsubstituted (C 10 -C 30 ) fused ring group, adjacent T1 to T 8 may be connected to each other to form a substituted or unsubstituted benzene, a substituted or unsubstituted (C 6 -C 30 ) heteroaromatic ring;

[0038] The substituents of the "substituted" group are selected from the group consisting of deuterium, fluorine, cyano, C 1 -C 10 alkyl, C 1 -C 10 alkoxy, C 3 -C 10 cycloalkyl or C 6 -C 12 aryl, or a combination of one or at least two thereof;

[0039] All hydrogen atoms in the compound of the structure shown in the general formula (2) may be all unsubstituted by deuterium, all substituted by deuterium or partially substituted by deuterium;

[0040] The heteroaromatic group is a monocyclic aromatic group or a polycyclic aromatic system containing at least one heteroatom, and the heteroatoms include, but are not limited to, O, S, and N.

[0041] Furthermore, L is independently selected from a linking bond, a deuterated or non-deuterated group as follows: phenyl, biphenyl, terphenyl, pyridyl, phenylpyridyl, quaterphenyl;

[0042] Ar is independently selected from hydrogen or the following groups:

[0043]

[0044] T 1 -T 8 are each independently selected from hydrogen, deuterium or the following groups:

[0045]

[0046] wherein D represents deuterium, n is selected from 0, 1, 2, 3; m is selected from 0, 1, 2, 3, 4; p is selected from 0, 1, 2, 3, 4, 5;

[0047] represents the substitution position, and * represents the ring junction of adjacent T1-T8.

[0048] According to an embodiment of the present invention, the second host material is a compound having the following structure:

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] The above is the specific structural formula of the second host material. The present invention preferably adopts the above structure but is not limited thereto.

[0061] The present invention also provides a preparation method of an organic electroluminescent material containing a dual-host material, including synthesizing the first host material and the second host material. The specific steps are as follows:

[0062] (I) Synthesis of the first host material:

[0063] (1) Under nitrogen protection, 55% sodium hydride (1.25 eq) and anhydrous DMF are added to a reaction vessel and stirred. Then, at room temperature, 5,11-dihydroindolo[3,2-b]carbazole-1,2,3,4,6,7,8,9,10,12-d10 (1 eq, CAS: 3033098-24-4) is dissolved in anhydrous DMF and slowly added dropwise to the reaction vessel. After the addition is complete, stirring is continued for 1 hour. Then, reactant 1 (1 eq) is dissolved in anhydrous DMF and slowly added dropwise to the reaction vessel. After the addition is complete, stirring is continued for 3 hours. Then, water is added to the system to precipitate a solid, which is filtered by suction, and the crude product is purified by column chromatography to obtain intermediate 1-1.

[0064] (2) Under nitrogen protection, 55% sodium hydride (1.25 eq) and anhydrous DMF are added to a reaction vessel and stirred. Then, at room temperature, intermediate 1-1 (1 eq) is dissolved in anhydrous DMF and slowly added dropwise to the above reaction vessel. After the addition is complete, stirring is continued for 1 hour. Then, reactant 2 (1 eq) is dissolved in anhydrous DMF and slowly added dropwise to this reaction vessel. After the addition is complete, stirring is continued for 3 hours. Then, water is added to the system to precipitate a solid for suction filtration, and the crude product is purified by column chromatography to obtain the compound with the structure shown in Formula 1. Its synthetic route is as follows:

[0065]

[0066] (II) Synthesis of the second host material

[0067] Weigh reactant 3 (1 eq), reactant 4 (1 eq), and sodium tert-butoxide (3 eq) and add them to the reaction vessel in sequence. Then add toluene as the reaction solvent, and add the catalyst Pd under nitrogen protection 2 (dba) 3 (0.02 eq) and P(t-Bu) 3 (0.04 eq). Reflux at 120 °C for 24 hours under nitrogen protection, then cool to 25 °C, add pure water to it, stir for 30 minutes, then let it stand for liquid separation, separate the liquid, and perform column chromatography to obtain the compound with the structure shown in Formula 2.

[0068]

[0069] In one embodiment of the present invention, the organic electroluminescent material further includes a doping material.

[0070] In one embodiment of the present invention, the mass ratio of the dual host material to the doping material in the organic electroluminescent material is (5 - 199):1; preferably (5 - 100):1, more preferably (5 - 15):1.

[0071] The present invention also provides an organic electroluminescent device, which includes the dual host material or the organic electroluminescent material.

[0072] In one embodiment of the present invention, the organic electroluminescent device includes a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode arranged in sequence; the material of the light-emitting layer includes the dual host material or the organic electroluminescent material.

[0073] In one embodiment of the present invention, the preparation method of the light-emitting layer includes, but is not limited to, forming the light-emitting layer by solution coating method and vacuum deposition method with the organic electroluminescent material.

[0074] In one embodiment of the present invention, the solution coating method includes one or more of spin coating, dip coating, inkjet printing, screen printing, spraying method, but is not limited thereto.

[0075] In one embodiment of the present invention, the first electrode is an anode.

[0076] As the anode material, generally, in order to enable holes to be smoothly injected into the organic layer, a material with a large work function is preferred.

[0077] In one embodiment of the present invention, the anode material includes: metals, such as vanadium, chromium, copper, zinc and other metals or their alloys; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO) or indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO / Al or SnO 2 / Sb; conductive polymers, such as poly(3-methylthiophene), polypyrrole or polyaniline; but not limited thereto.

[0078] In certain embodiments of the present invention, the anode is an ITO anode.

[0079] In one embodiment of the present invention, the material of the hole injection layer is selected from one or more of metal porphyrins, oligothiophenes, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, polyaniline-based and polythiophene-based conductive polymers.

[0080] In one embodiment of the present invention, the material of the hole injection layer is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the material of the hole injection layer is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0081] In one embodiment of the present invention, the material of the hole transport layer is selected from one or more of arylamine-based organic materials, conductive polymers, and block copolymers having both a conjugated part and a non-conjugated part.

[0082] In one embodiment of the present invention, the material of the hole transport layer 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.

[0083] In one embodiment of the present invention, the electron transport layer is selected from one or more of Al complexes of 8-hydroxyquinoline and organic radical compounds, but not limited thereto.

[0084] In one embodiment of the present invention, the thickness of the electron transport layer is 1 nm to 50 nm.

[0085] For example, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm.

[0086] The electron transport layer can prevent the degradation of electron transport characteristics, prevent the increase of driving voltage caused by too thick electron transport layer, and play a role in promoting electron transport. The material of the electron transport layer is used to receive electrons from the cathode and transport the electrons to the light-emitting layer, and has a high electron mobility.

[0087] The electron injection layer can play a role in promoting electron injection, and the material of the electron injection layer preferably has the ability to transport electrons, has an electron injection effect 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.

[0088] In one embodiment of the present invention, the electron injection layer is selected from one or more of fluorenone, anthraquinodimethane, biphenylquinone, thiopyran dioxide, imidazole, perylene tetracarboxylic acid, fluoreneylidene methane, anthrone or its derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, but not limited thereto.

[0089] In one embodiment of the present invention, the second electrode is a cathode.

[0090] As the cathode material, generally in order to facilitate the injection of electrons into the organic layer, a material with a small work function is preferred.

[0091] In one embodiment of the present invention, specific examples of the cathode material include: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead and other metals or their alloys; multi-layer structure materials, such as LiF / Al or LiO 2 / Al; but not limited thereto.

[0092] In certain embodiments of the present invention, the material of the cathode can be Al.

[0093] In one embodiment of the present invention, the organic electroluminescent device can be a top emission type, a bottom emission type or a double-sided emission type.

[0094] The numerical ranges described in the present invention not only include the above-listed point values, but also include any point values between the above numerical ranges not listed. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0095] Compared with the prior art, the beneficial effects of the present invention are:

[0096] The present invention provides an organic electroluminescent material with a dual host material, which uses a first host compound with a specific structure and a second host compound with a specific structure in combination. Among them, the first host compound (Formula 1) with a specific structure has a high electron injection and transport ability. By connecting other groups through triazine, there is a steric effect, which can inhibit the approach of deuterated indolocarbazole molecules to each other. And, by connecting other groups through triazine, the electron injection and transport ability to the light-emitting layer can be controlled at a relatively high level.

[0097] The hole injection and transport ability of the second host carbazole compound (Formula 2) is high. By changing the bonding pattern of the carbazole ring and the type / quantity of the substituents on the skeleton, the hole injection and transport property can be controlled at a high level.

[0098] Therefore, by using a compound formed by mixing the first host compound and the second host compound as the double-host material, the injection amounts of the two charges into the organic layer can be adjusted to a preferred range, thereby achieving better device characteristics. Moreover, by applying the compound of the double-host material to the light-emitting layer material of an organic electroluminescent device, the driving voltage can be reduced, the light-emitting efficiency of the organic electroluminescent device can be improved, and the service life can be extended. Description of the Drawings

[0099] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of the compound G1-1 of the first host material prepared in the present invention. Detailed Embodiments

[0100] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only for exemplarily illustrating and explaining the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope intended to be protected by the present invention.

[0101] Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available products.

[0102] Preparation of the compound G1-1 of the first host material

[0103] Under nitrogen protection, 55% sodium hydride (50 mmol) and 70 mL of anhydrous DMF were added to a reaction vessel and stirred. Then, 5,11-dihydroindolo[3,2-b]carbazole-1,2,3,4,6,7,8,9,10,12-d10 (40 mmol) was dissolved in 150 mL of anhydrous DMF at room temperature and slowly added dropwise to the above reaction vessel. After the addition was complete, stirring was continued for 1 hour. Then, 2-chloro-4,6-diphenyl-1,3,5-triazine (80 mmol) was dissolved in 300 mL of anhydrous DMF and slowly added dropwise to the above reaction vessel. After the addition was complete, stirring was continued for 8 hours. Then, water was added to the system to precipitate a solid, which was filtered by suction, and the crude product was purified by column chromatography to obtain the final product G1-1 (12.54 g, yield 43%, HPLC > 99%, mass spectrometry test value 728.96).

[0104] The nuclear magnetic resonance hydrogen spectrum of the compound G1-1 of the first host material is shown in Figure 1 .

[0105]

[0106] Compound G1-5 for preparing the first host material

[0107] (1) Under nitrogen protection, 55% sodium hydride (50 mmol) and 70 mL of anhydrous DMF were added to a reaction vessel and stirred. Then, at room temperature, 5,11-dihydroindolo[3,2-b]carbazole-1,2,3,4,6,7,8,9,10,12-d10 (40 mmol) was dissolved in 150 mL of anhydrous DMF and slowly added dropwise to the reaction vessel. After the addition was complete, stirring was continued for 1 hour. Then, 2-chloro-4,6-bis(phenyl-d5)-1,3,5-triazine (40 mmol) was dissolved in 150 mL of anhydrous DMF and slowly added dropwise to the reaction vessel. After the addition was complete, stirring was continued for 3 hours. Then, water was added to the system to precipitate a solid, which was filtered by suction. The crude product was purified by column chromatography to obtain intermediate G1-5-1 (12.38 g, yield 61%, HPLC > 99%, mass spectrometry test value 507.91).

[0108] (2) Under nitrogen protection, 55% sodium hydride (30 mmol) and 42 mL of anhydrous DMF were added to a reaction vessel and stirred. Then, at room temperature, intermediate G1-5-1 (24 mmol) was dissolved in 90 mL of anhydrous DMF and slowly added dropwise to the above reaction vessel. After the addition was complete, stirring was continued for 1 hour. Then, 2-([1,1'-biphenyl]-4-yl-2',3',4',5',6'-d5)-4-chloro-6-phenyl-1,3,5-triazine (24 mmol) was dissolved in 90 mL of anhydrous DMF and slowly added dropwise to the above reaction vessel. After the addition was complete, stirring was continued for 3 hours. Then, water was added to the system to precipitate a solid, which was filtered by suction. The crude product was purified by column chromatography to obtain the final product G1-5 (10.63 g, yield 54%, HPLC > 99%, mass spectrometry test value 820.28).

[0109]

[0110] Compound G2-4 for preparing the second host material

[0111] 9H,9'H-3,3'-bicarbazole (30 mmol), bromobenzene (60 mmol), and sodium tert-butoxide (90 mmol) were successively added to a reaction vessel, and then 150 mL of toluene was added as the reaction solvent. Under nitrogen protection, the catalyst Pd 2 (dba) 3 (0.6 mmol) and P(t-Bu) 3(1.2 mmol), reflux at 120 °C for 24 hours under nitrogen protection, then cool to 25 °C, add pure water thereto, stir for 30 minutes, then let stand for liquid separation, separate the liquid, and perform column chromatography to obtain the final product G2-4 (11.04 g, yield 76%, HPLC > 99%, mass spectrometry test value 484.36).

[0112]

[0113] Preparation of the second host material compound G2-47

[0114] Weigh 5,11-dihydroindolo[3,2-b]carbazole (30 mmol), 4-bromo-1,1'-biphenyl (60 mmol), and sodium tert-butoxide (90 mmol) and add them to the reaction vessel in sequence. Then add 150 mL of toluene as the reaction solvent, and add the catalyst Pd 2 (dba) 3 (0.6 mmol) and P(t-Bu) 3 (1.2 mmol), reflux at 120 °C for 24 hours under nitrogen protection, then cool to 25 °C, add pure water thereto, stir for 30 minutes, then let stand for liquid separation, separate the liquid, and perform column chromatography to obtain the final product G2-47 (12.27 g, yield 73%, HPLC > 99%, mass spectrometry test value 560.38).

[0115]

[0116] Preparation of an organic electroluminescent device

[0117] The preparation method of the organic electroluminescent device is as follows:

[0118] (1) Wash the ITO (indium tin oxide) glass substrate with a thickness of 1500 Å twice in distilled water, ultrasonically wash for 30 minutes, then wash repeatedly with distilled water twice, and ultrasonically wash for 10 minutes. After the washing is completed, ultrasonically wash with methanol, acetone, and isopropanol in sequence (each washing for 5 minutes), dry, and then transfer to a plasma cleaner for washing for 5 minutes to obtain the ITO anode.

[0119] (2) In an evaporation coater, vacuum deposit HIL on the surface of the ITO anode obtained in step (1) with a thickness of 700 Å to obtain a hole injection layer. The HIL structure is as follows.

[0120] (3) Vacuum deposit HTL on the surface of the hole injection layer obtained in step (2). Deposit HTL1 with a thickness of 50 Å and HTL2 to a thickness of 700 Å to form a hole transport layer. The structures of HTL1 and HTL2 are as follows.

[0121] (4) Evaporate the light-emitting layer material on the surface of the hole transport layer, and perform linear gradient co-evaporation using the multi-source co-evaporation method with a thickness of 300 Å to obtain the light-emitting layer. The light-emitting layer material includes a double host material and a doping material. The mass ratio of the first host compound to the second host compound in the double host material is 60:40, and the mass ratio of the double host material to the doping material is 10:1. The double host materials are the host materials provided in Device Examples 1-42, Comparative Examples 1-18, and Parallel Comparative Examples 1-6 respectively; the structure of the doping material Dopant is as follows.

[0122] (5) Evaporate HBL on the surface of the light-emitting layer obtained in step (4) with a thickness of 100 Å to form a hole blocking layer. The structure of HBL is as follows.

[0123] (6) Vacuum evaporate ETL on the surface of the hole blocking layer obtained in step (5) with a thickness of 300 Å to obtain the electron transport layer. The structure of ETL is as follows.

[0124] (7) Vacuum evaporate Liq on the surface of the electron transport layer obtained in step (6) with a thickness of 15 Å; obtain the electron injection layer. The structure of EIL is as follows.

[0125] (8) Evaporate 1200 Å of Al on the surface of the electron injection layer obtained in step (7) to form the cathode, and then the organic electroluminescent device can be obtained.

[0126] Materials used in each functional layer of the device:

[0127]

[0128] Device Examples 1-42, Comparative Examples 1-18, Parallel Comparative Examples 1-6:

[0129] Device Examples 1-42 adopt the double host materials of the present invention. The combination of the double host materials is shown in Table 2. Among them, for the scheme where the double host material includes the compound of the first host material and the compound of the second host material, the mass ratio of the compound of the first host material to the compound of the second host material is 60:40.

[0130] Comparative Examples 1-18 adopt one or two compounds with the structures shown in Table 1 as the host materials.

[0131] In Parallel Comparative Examples 1-6, one host material compound with the structure shown in General Formula (1) or General Formula (2) of the present invention and one compound with the structure shown in Table 1 are respectively used for mutual matching.

[0132] In Table 2, "-" indicates that the compound is not in the host material; the structures of E and F are shown as follows respectively.

[0133] The comparative examples are shown in Table 1 below.

[0134] Table 1

[0135]

[0136]

[0137] The driving voltage and luminous efficiency of the test organic electroluminescent device at a brightness of 15,000 nits, and the time (lifetime; T95) taken for the brightness to decrease from 100% to 95% were tested. The test results are shown in Table 2 below.

[0138] Table 2

[0139]

[0140]

[0141]

[0142] It can be seen from Device Examples 1-42 that when the host materials of the light-emitting layer are compounded with the compound of the first host material and the compound of the second host material of the present invention, applying them to the device can significantly improve the luminous efficiency and service life.

[0143] By comparing Comparative Examples 1-14 with Comparative Examples 15-18, it can be known that if only any one of them is selected, it will cause a significant reduction in the luminous efficiency of the device, a significant shortening of the service life, and an increase in voltage.

[0144] From the comparison of the device performance prepared by Device Examples 1-42 and Parallel Comparative Examples 1-6, it can be known that the efficiency of the organic electroluminescent device prepared by Parallel Comparative Examples 1-6 is 34.7 - 36.1 cd / A, the driving voltage is 3.42 - 3.55 V, and the lifetime is 472 - 487 h; while the luminous efficiency of the organic electroluminescent device prepared by Device Examples 1-42 of the present invention using a dual host material is 41.1 - 44.9 cd / A, which is significantly higher than the luminous efficiency of the devices in Parallel Comparative Examples 1-6; the driving voltage of Device Examples 1-42 of the present invention is 3.09 - 3.27 V, which is significantly lower than the driving voltage of the devices in Parallel Comparative Examples 1-6; the lifetime of the devices in Device Examples 1-42 of the present invention is 571 - 610 h, which is much higher than the service life of the devices in Parallel Comparative Examples 1-6.

[0145] The reason is mainly that the present invention uses a compound of the first host material with a specific structure, which has a high electron injection and transport ability. By connecting other groups through triazine, there is a steric effect, which can inhibit the approach of deuterated indolocarbazole molecules to each other. And by connecting other groups through triazine, the electron injection and transport ability to the light-emitting layer can be controlled at a relatively high level.

[0146] On the other hand, the hole injection and transport energy of the second host carbazole compound used is high, and by changing the bonding pattern of the carbazole ring and the type / number of substituents for the skeleton, the hole injection and transport properties can be controlled at a high level.

[0147] Therefore, by using a mixture of the first host material and the second host material compounds of the present invention, the injection amounts of the two charges into the organic layer can be adjusted to an optimal range, thereby achieving better device characteristics. In the case of a phosphorescent EL device, there is no energy outflow from the light-emitting layer, the voltage is low, the efficiency is high, and long life can be achieved.

[0148] The specific embodiments described above have elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organic electroluminescent compound, characterized in that: The organic electroluminescent compound has a chemical structure shown in general formula (1): wherein R1-R4 are each independently selected from substituted or unsubstituted C6-C 30 Aryl, C6-C 30 wherein the heteroatom in the heteroaryl group is selected from O, N or S; All hydrogen atoms in the general formula (1) are not replaced by deuterium, are replaced by deuterium or are partially replaced by deuterium; The substituents of the "substituted" group are selected from deuterium, fluorine, cyano, C1-C 10 Alkyl, C1-C 10 Alkoxy, C3-C 10 Cycloalkyl or C6-C 12 One or a combination of at least two of the aromatic groups.

2. The organic electroluminescent compound according to claim 1, characterized in that The R1-R4 are independently selected from substituted or unsubstituted C6-C 18 aryl, substituted or unsubstituted C6-C 15 The heteroaryl group.

3. The organic electroluminescent compound according to claim 1, characterized in that The R1-R4 are selected from the following groups, which can be connected at any substitutable position, and the following groups can be further substituted by deuterium.

4. The organic electroluminescent compound according to claim 1, characterized in that The structural compound represented by the general formula (1) is selected from any one of G1-1 to G1-240:

5. An organic electroluminescent material containing a dual host material, characterized in that: The organic electroluminescent material comprises a first host material and a second host material, wherein the first host material has a compound having a structure represented by the general formula (1); and the second host material has a compound having a structure represented by the general formula (2): wherein Ar is selected from hydrogen, substituted or unsubstituted (C6-C 30 ) aryl, substituted or unsubstituted (C6-C 30 ) heteroaryl; L is selected from the group consisting of a linker, an unsubstituted C6-C 18 Aryl, substituted or unsubstituted C6-C 18 heteroaryl; T1 to T8 are each independently selected from hydrogen, deuterium, substituted or unsubstituted (C6-C 30 ) aryl, substituted or unsubstituted (C6-C 30 ) heteroaryl, substituted or unsubstituted (C 10 -C 30 ) fused ring group, adjacent T1 to T8 can be connected to each other to form substituted or unsubstituted benzene, substituted or unsubstituted (C6-C 30 ) heteroaromatic ring; The substituents of the "substituted" group are selected from deuterium, fluorine, cyano, C1-C 10 Alkyl, C1-C 10 Alkoxy, C3-C 10 Cycloalkyl or C6-C 12 One or a combination of at least two of the aromatic groups; All hydrogen atoms in the structural compound represented by the general formula (2) may be completely unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium; The heteroaryl group is a monocyclic aromatic group or a polycyclic aromatic system including at least one heteroatom, and the heteroatom includes but is not limited to O, S, and N.

6. The organic electroluminescent material according to claim 5, characterized in that: L is independently selected from the following groups, deuterated or undeuterated, including phenyl, biphenyl, terphenyl, pyridyl, phenylpyridyl, and quaterphenyl; Ar is independently selected from hydrogen or any of the following groups:

7. The organic electroluminescent material according to claim 5, characterized in that: T1-T8 are each independently selected from hydrogen, deuterium or any one of the following groups: Wherein, D represents deuterium, n is selected from 0, 1, 2, 3; m is selected from 0, 1, 2, 3, 4; p is selected from 0, 1, 2, 3, 4, 5; indicates the substitution position, and * indicates the adjacent T1-T8 ring connection.

8. The organic electroluminescent material according to claim 5 or 6, characterized in that: The second host material is a compound having the structure shown below:

9. The organic electroluminescent material according to claim 5, characterized in that: The organic electroluminescent material further contains a doping material, and the mass ratio of the dual host material to the doping material in the organic electroluminescent material is (5-199):

1.

10. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the organic electroluminescent material containing dual host materials according to any one of claims 5 to 9.

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