Organic electroluminescent material and light-emitting device

Abstract

The present invention relates to the technical field of organic electroluminescent display, and specifically discloses a novel organic electroluminescent material and an organic electroluminescent device prepared by using the luminescent material. The organic electroluminescent material provided by the present invention comprises a first compound and a second compound, wherein the first compound and the second compound are independently selected from the structure shown in general formula (I), and the first compound and the second compound are different. The present invention obtains a luminescent layer co-doped with a plurality of guest luminescent materials by combining two different metal complexes of the first compound and the second compound, so that the prepared organic electroluminescent device can obtain a lower voltage, a higher luminous efficiency and a longer life, and can significantly improve the performance of the device.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescent display, and specifically discloses a novel organic electroluminescent material and an organic electroluminescent device prepared by using the luminescent material. Background Art

[0002] Organic electronic devices include, but are not limited to, the following: organic light emitting diodes (OLEDs), organic field effect transistors (O-FETs), organic light emitting transistors (OLETs), organic photovoltaics (COPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field effect devices (OFQDs), light emitting electrochemical cells (LEGS), organic laser diodes, and organic plasmonic light emitting devices.

[0003] In 1987, Tang et al. of Eastman Kodak Company in the United States first reported a green electroluminescent device made of a double-layer organic film. The device used indium tin oxide (ITO) as the anode, and a 75nm thick amorphous pinhole-free aromatic diamine film was evaporated on the anode for hole transport. Then, a 60nm thick 8-hydroxyquinoline aluminum film was deposited on the aromatic diamine film as an electron transport layer and a light-emitting layer. A magnesium-silver alloy was used as the cathode. This double-layer film structure successfully reduced the turn-on voltage to 5.5V and achieved high radiant luminescence (>1000cd·m -2 ), with a wavelength of 550nm and an external quantum efficiency of 1.0%, which has great practical significance. In 1994, Kido et al. in Japan prepared the first organic electroluminescent device that emits white light. They doped blue, green and orange fluorescent dyes into poly (N-vinyl carbazole) (PVK) film as a hole transport layer and emission layer, 1,2,4-triazole derivatives (TAZ) as a hole blocking layer, and 8-hydroxyquinoline aluminum (Alq3) as an electron transport layer. The device composition is: glass substrate / ITO / PVK / TAZ / Alq3 / Mg:Ag multilayer structure. At a driving voltage of 14V, a wide range of visible light regions and a brightness of up to 3400cd·m -2 This high-brightness white emission is achieved by doping a polymer film with fluorescent compounds of various colors to form a single light-emitting layer. This discovery by Kido et al. has added a strong touch to the application of organic electroluminescence, opened the door to organic light-emitting devices in the field of lighting, and promoted the further development of organic light-emitting devices.

[0004] The light emitted by organic electroluminescent devices is divided into fluorescence and phosphorescence. The light emitted by the energy of singlet excitons is fluorescence, while the light emitted by the energy of both singlet and triplet excitons is phosphorescence. Since the number of singlet and triplet states formed by excitons has a fixed ratio of 1:3, theoretically, the internal quantum efficiency of a fluorescent device that only uses singlet excitons is only 25% at most, while the internal quantum efficiency of phosphorescence can reach 100%.

[0005] At present, organic metal complexes and organic electroluminescent devices with phosphorescent emission have been reported, but in many applications such as TV and lighting equipment, the life of OLED is insufficient, and more efficient OLED is still needed. Typically, the higher the brightness of the OLED, the shorter the life of the OLED. Therefore, for long-term use and high-resolution displays, OLEDs with high luminous efficiency and long life are needed.

[0006] A large number of phosphorescent materials are disclosed in the prior art. When these materials are used in organic electroluminescent devices, some have a long lifespan and some have a high external quantum efficiency. However, they often cannot have both lifespan and efficiency. In practical applications, trade-offs need to be made based on demand.

[0007] In view of the above problems, the present invention has conducted in-depth research in order to provide an organic electroluminescent device with improved comprehensive performance. Summary of the invention

[0008] The purpose of the present invention is to develop a new organic electroluminescent material. By using a first compound and a second compound as a combination of two different metal complexes, a light-emitting layer co-doped with multiple guest light-emitting materials is obtained, so that the prepared organic electroluminescent device can obtain a lower voltage, a higher luminous efficiency and a longer life, which can significantly improve the performance of the device.

[0009] Specifically, in a first aspect, the present invention provides an organic electroluminescent material, comprising a first compound and a second compound, wherein the first compound and the second compound are independently selected from the structure represented by general formula (I), and the first compound and the second compound are different;

[0010]

[0011] in:

[0012] R 1 ~R 11 are independently selected from hydrogen, deuterium, alkyl, deuterated alkyl, cyano, alkoxy, alkylamino, alkylthio, fluorine, trifluoromethyl, aromatic and heterocyclic aromatic groups, and / or R 1 ~R 11The adjacent substituents are bridged to form a ring structure;

[0013] L is a monovalent dicoordinate anion, wherein the bonding atoms X and Y are independently selected from oxygen atoms, nitrogen atoms, and carbon atoms;

[0014] n is 1, 2 or 3.

[0015] As an embodiment of the present invention, L is phenylpyridyl, substituted phenylpyridyl, acetylacetonyl or substituted acetylacetonyl;

[0016] Preferably, L is a group represented by formula L1 or formula L2:

[0017]

[0018] in:

[0019] In formula L1, R 12 ~R 19 are independently selected from hydrogen atoms, deuterium atoms, alkyl groups, deuterated alkyl groups, alkoxy groups, alkylamino groups, alkylthio groups, fluorine atoms, trifluoromethyl groups, aromatic groups and heterocyclic aromatic groups, and / or R 12 ~R 19 The adjacent substituents are bridged to form a ring structure;

[0020] In formula L2, R 20 ~R 26 are independently selected from hydrogen atoms, deuterium atoms, alkyl groups, deuterated alkyl groups, alkoxy groups, alkylamino groups, alkylthio groups, fluorine atoms, trifluoromethyl groups, aromatic groups and heterocyclic aromatic groups, and / or R 20 ~R 26 Adjacent substituents are bridged to form a ring structure.

[0021] More preferably, L is arbitrarily selected from the following groups:

[0022]

[0023] As a preferred embodiment of the present invention, the first compound and the second compound are independently selected from compounds represented by Formula I, Formula II or Formula III;

[0024] Preferably, the first compound and the second compound are both selected from the compounds represented by the general formula I, or are both selected from the compounds represented by the general formula II, or are both selected from the compounds represented by the general formula III, and the first compound and the second compound are different;

[0025]

[0026] Wherein, m is 1 or 2.

[0027] R in the general formula I 1 ~R 11 As defined above.

[0028] R in Formula II or Formula III 1 ~R 26 As defined above.

[0029] As a preferred embodiment of the present invention, in the above general formula (I) or general formula I or general formula II or general formula III, the R 1 ~R 11 are independently selected from hydrogen atoms, deuterium atoms, C 1 ~C 5 Alkyl, C 1 ~C 5 deuterated alkyl, cyano, alkoxy containing 1 to 5 C atoms, alkylamino containing 1 to 5 C atoms, alkylthio containing 1 to 5 C atoms, fluorine atom, trifluoromethyl, phenyl, substituted phenyl, heterocyclic aromatic group; and / or, R 1 ~R 11 The adjacent substituents are bridged to form a ring structure, wherein the ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle and a substituted or unsubstituted six-membered heterocycle, and the substituent used is C 1 ~C 5 The five-membered heterocyclic ring or the six-membered heterocyclic ring contains at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom, a sulfur atom, and a nitrogen atom.

[0030] In this application, C 1 ~C 5 The alkyl group may be a straight chain alkyl group or a branched alkyl group, such as methyl, ethyl, n-propane, isopropyl, sec-butyl, n-butyl, isobutyl, tert-butyl, pentyl, neopentyl, etc.

[0031] C 1 ~C 5 The deuterated alkyl group is a C 1 ~C 5 Similarly, C 1 ~C 5 The alkyl group may be a straight chain alkyl group or a branched chain alkyl group. 1 ~C 5 The deuterated alkyl group may be, for example, a deuterated methyl group, a deuterated isopropyl group, a deuterated pentyl group, a deuterated neopentyl group, or the like.

[0032] Alkoxy groups containing 1 to 5 carbon atoms are C n H 2n+1The group represented by O-, wherein n is 1 to 5. The alkoxy group containing 1 to 5 carbon atoms may be methoxy, ethoxy, or the like.

[0033] R 1 ~R 11 The adjacent substituents in the formula (a) can also form a parallel ring structure by bridging. When the parallel ring structure is formed, the parallel ring structure can be any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle, and a substituted or unsubstituted six-membered heterocycle. The five-membered heterocycle or the six-membered heterocycle contains at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom, a sulfur atom, and a nitrogen atom. For example, the parallel ring structure can be a benzo ring, a furan ring, a thienyl ring, a cyclopentene ring, etc. The parallel ring structure can be further substituted by a substituent, such as substituted by a benzo group, substituted by an alkyl group, etc.

[0034] As a preferred embodiment of the present invention, in the general formula II, the R 12 ~R 19 are independently selected from hydrogen atoms, deuterium atoms, C 1 ~C 5 Alkyl, fluorine atom, phenyl, substituted phenyl, C 1 ~C 5 deuterated alkyl, cyano, alkoxy containing 1 to 5 C atoms, alkylamino containing 1 to 5 C atoms, alkylthio containing 1 to 5 C atoms, trifluoromethyl, heterocyclic aromatic group; or, R 12 ~R 19 The adjacent substituents are bridged to form a ring structure, wherein the ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle and a substituted or unsubstituted six-membered heterocycle, and the substituent used is C 1 ~C 5 The alkyl group is phenyl, benzo, pyrido, alkyl-substituted pyrido, deuterated alkyl-substituted pyrido, and the five-membered heterocyclic ring or the six-membered heterocyclic ring contains at least one heteroatom, and the heteroatom is arbitrarily selected from oxygen atom, sulfur atom, and nitrogen atom.

[0035] As a preferred embodiment of the present invention, in the general formula III, the R 20 ~R 26 are independently selected from hydrogen atoms, deuterium atoms, C 1 ~C 5 Alkyl groups, fluorine atoms, C 1 ~C 5 deuterated alkyl, alkoxy containing 1 to 5 C atoms, alkylamino containing 1 to 5 C atoms, alkylthio containing 1 to 5 C atoms, and trifluoromethyl.

[0036] As a further preferred embodiment of the present invention, in the above general formula (I) or general formula I or general formula II or general formula III, wherein R 1 ~R 11 are independently selected from hydrogen atoms, C 1 ~C 5 Alkyl, C 1 ~C 5 deuterated alkyl, phenyl, fluorine atom, alkoxy group containing 1 to 5 carbon atoms, trifluoromethyl; or, R 1 ~R 11 The adjacent substituents are bridged to form a parallel ring structure, wherein the parallel ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted benzene ring, and a substituted or unsubstituted five-membered heterocycle, and the substituent used is C 1 ~C 5 The five-membered heterocyclic ring has at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom and a sulfur atom.

[0037] More preferably, wherein R 1 ~R 11 are independently selected from hydrogen, methyl, deuterated methyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, deuterated isopropyl, phenyl, pentyl, deuterated pentyl, fluorine, methoxy; or, R 1 ~R 11 The adjacent substituents are bridged to form a parallel ring structure, wherein the parallel ring structure is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, and a substituted or unsubstituted cyclopentene ring, and the substituents used are benzo and methyl.

[0038] As a further preferred embodiment of the present invention, in the general formula II, the R 12 ~R 19 are independently selected from hydrogen atoms, C 1 ~C 5 Alkyl, fluorine atom, phenyl, C 1 ~C 5 deuterated alkyl; or, R 12 ~R 19 The adjacent substituents are bridged to form a ring structure, wherein the ring structure is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted five-membered heterocycle, and the substituent used is C 1 ~C 5 The alkyl group may be phenyl, benzo, pyrido, pyrido substituted by an alkyl group having 1 to 5 C atoms, or pyrido substituted by a deuterated alkyl group having 1 to 5 C atoms, wherein the five-membered heterocyclic ring has at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom and a sulfur atom.

[0039] More preferably, wherein R 12 ~R 19 are independently selected from hydrogen, methyl, fluorine, phenyl, deuterated methyl, isopropyl, deuterated isopropyl; or, R 12 ~R 19 The adjacent substituents are bridged to form a parallel ring structure, which is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted furan ring, and a substituted or unsubstituted six-membered ring, and the substituent used is a deuterated methyl-substituted pyrido group, a methyl-substituted pyrido group or a benzo group.

[0040] As a further preferred embodiment of the present invention, in the above general formula III, the R 20 ~R 26 are independently selected from hydrogen atoms, deuterium atoms, C 1 ~C 5 of alkyl.

[0041] More preferably, wherein R 20 ~R 26 Each is independently selected from a hydrogen atom, a methyl group and an ethyl group.

[0042] As a preferred embodiment of the present invention, the organic electroluminescent material, wherein the first compound and the second compound are independently selected from the compounds represented by the following structural formulas, and the first compound and the second compound are different;

[0043]

[0044]

[0045]

[0046]

[0047]

[0048] Preferably, the first compound and the second compound are independently selected from the compounds shown in I-1 to I-30, and the first compound and the second compound are different;

[0049] Alternatively, the first compound and the second compound are independently selected from the compounds shown in II-1 to II-44, and the first compound and the second compound are different;

[0050] Alternatively, the first compound and the second compound are independently selected from the compounds shown in III-1 to III-20, and the first compound and the second compound are different.

[0051] As a preferred embodiment of the present invention, in the organic electroluminescent material, the mixing mass ratio of the first compound to the second compound is between 1:99 and 99:1.

[0052] Preferably, the mixing mass ratio of the first compound to the second compound is between 1:4 and 5:1, and further preferably, the mixing mass ratio of the first compound to the second compound is between 1:4 and 4:1.

[0053] In a second aspect, the present invention provides the use of the organic electroluminescent material in preparing an organic electroluminescent device.

[0054] Preferably, the organic electroluminescent material is used as a doping material for a light-emitting layer in an organic electroluminescent device.

[0055] Further preferably, in the light-emitting layer, the organic electroluminescent material accounts for 4% to 20% of the total mass of the light-emitting layer, and more preferably 4% to 10%.

[0056] In a third aspect, the present invention provides an organic electroluminescent device made of the organic electroluminescent material, comprising:

[0057] anode,

[0058] cathode,

[0059] And an organic layer arranged between the anode and the cathode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the organic electroluminescent material of the present invention.

[0060] Preferably, the light-emitting layer comprises a host material and a dye material, and the dye material comprises the organic electroluminescent material described in the present invention.

[0061] Further preferably, the doping concentration of the organic electroluminescent material of the present invention in the light-emitting layer is 4-20%, preferably 4-10%, and more preferably 5-9%.

[0062] As a preferred embodiment of the present invention, the main material of the organic electroluminescent device contains at least one chemical group selected from the following compositions: benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolecarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silylfluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

[0063] Preferably, the organic electroluminescent device emits green light or yellow light.

[0064] In a fourth aspect, the present invention provides a display assembly, comprising the organic electroluminescent device described in the present invention.

[0065] The present invention provides a novel organic electroluminescent device, wherein a light-emitting layer is co-doped with a plurality of guest light-emitting materials. By using a first compound and a second compound, two different metal complexes, in combination, the prepared organic electroluminescent device can obtain a lower voltage, a higher light-emitting efficiency and a longer life, and can significantly improve the performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 is the H NMR spectrum of compound III-1;

[0067] Figure 2 is the H NMR spectrum of compound III-2;

[0068] Figure 3 is the H NMR spectrum of compound III-3;

[0069] Figure 4 This is the H NMR spectrum of compound II-2. DETAILED DESCRIPTION

[0070] The technical solution of the present invention is described in detail below.

[0071] OLEDs can be manufactured on a variety of substrates, such as glass, plastic, and metal. OLEDs have multiple layers, including a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode. They can be manufactured by depositing the described layers in sequence. The properties and functions of each layer and exemplary materials are described in more detail in columns 6-10 of U.S. Patent No. 7,279,704 B2, the entire contents of which are incorporated herein by reference.

[0072] There are more examples of each of these layers. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is one doped with F at a molar ratio of 50:1. 4

[0013] An example of an n-doped electron transport layer is BPhen doped with Li at a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety.

[0013] An example of an n-doped electron transport layer is BPhen doped with Li at a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety.

[0013] U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes having a thin layer of a metal such as Mg:Ag and an overlying transparent, conductive, sputter-deposited ITO layer. The principles and use of barrier layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174H6, which is incorporated by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174H6, which is incorporated by reference in its entirety.

[0073] The above layered structure is provided by way of non-limiting example. The functions of an OLED can be achieved by combining the various layers described above, or some layers can be omitted entirely. It can also include other layers not explicitly described.

[0074] Devices manufactured according to embodiments of the present invention can be incorporated into various consumer products having one or more electronic component modules (or units) of the device. Some examples of these consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, smart phones, tablet computers, tablet phones, wearable devices, smart watches, laptop computers, digital cameras, camcorders, viewfinders, micro displays, 3-D displays, vehicle displays, and taillights.

[0075] The materials and structures described herein may also be used in other organic electronic devices listed above.

[0076] The specific materials used in the organic light-emitting devices described in the present invention can be used in combination with various other materials present in the device. The combination of these materials is described in detail in paragraphs 0132-0161 of U.S. Patent Application US2016 / 0359122A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0077] The materials described herein as specific layers that can be used in organic light-emitting devices can be used in combination with a variety of other materials present in the device. For example, the compounds disclosed herein can be used in combination with a variety of hosts, transport layers, barrier layers, injection layers, electrodes, and other layers that may be present. The combination of these materials is described in detail in paragraphs 0080-0101 of U.S. Patent Application US2015 / 0349273A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0078] In the embodiment of material synthesis, unless otherwise stated, all reactions are carried out under nitrogen protection. All reaction solvents are anhydrous and used as they are from commercial sources. The synthetic product uses one or more conventional equipment in the art (including but not limited to Agilent's liquid chromatograph, liquid chromatography-mass spectrometer, gas chromatography-mass spectrometer, differential scanning calorimeter, fluorescence spectrophotometer, electrochemical workstation, sublimator, etc.), and the structure is confirmed and the characteristics are tested by methods well known to those skilled in the art. In the embodiment of the device, the preparation and testing of the device also use conventional equipment in the art (including but not limited to the evaporation machine produced by Nanjing Institute of Micro-Science, the optical test system and life test system produced by Suzhou Fushida, the ellipsometer produced by Wuhan Yiguang Technology, etc.), and the method well known to those skilled in the art is tested. Since those skilled in the art are aware of the use of the above-mentioned equipment, the test method and other related contents, the inherent data of the sample can be obtained with certainty and without being affected, so the above-mentioned related contents will not be elaborated in this patent.

[0079] The technical scheme of the present invention is further described below by specific examples. The following examples are only used to illustrate the present invention, but are not used to limit the scope of the present invention. Any other equivalent changes or modifications that are completed without departing from the spirit disclosed by the present invention should be included in the scope of the claims.

[0080] The preparation methods of the first compound and the second compound used in the present invention are not limited. The following compounds are typically but not limitedly exemplified, and their synthesis routes and preparation methods are as follows.

[0081] Example 1 Synthesis of ligand P1

[0082]

[0083] The synthetic route is as follows:

[0084]

[0085] The specific experimental steps are:

[0086] (1) In a 2L three-necked flask equipped with a mechanical stirrer, 2-fluoronitrobenzene (14.1 g, 0.1 mol) and 2-bromoaniline (25.7 g, 0.15 mol) were added, stirred, protected by argon, heated to 180°C, and kept warm for more than 30 hours. During the reaction, the color gradually turned red and finally dark red. After the reaction, the organic phase was separated, extracted, dried, column chromatographed, and the solvent was dried to obtain 24.8 g of orange-red solid M1, with a yield of 85%.

[0087] (2) In a 1L three-necked flask equipped with a mechanical stirrer, add M1 (29.2 g, 0.1 mol), sodium sulfide nonahydrate (96 g, 0.4 mol), ethanol (200 mL), and water (100 mL), and heat to reflux under nitrogen protection. Reflux for 3 hours to terminate the reaction. Separate the organic phase, extract, dry, column chromatograph, and spin dry the solvent to obtain 22.8 g of white solid M2, with a yield of 87%.

[0088] (3) In a 1L three-necked flask equipped with a mechanical stirrer, add M2 (26.2 g, 0.1 mol) and 300 mL of acetone to completely dissolve, add a solution of KOH (11.2 g, 0.2 mol) dissolved in (50 mL) water, and then slowly drop o-bromobenzoyl chloride (22 g, 0.1 mol) into the reaction flask. Solid gradually precipitates in the reaction flask. After the dropwise addition is completed, react at room temperature for 2 hours to terminate the reaction. Adjust to neutral, separate the organic phase, extract, dry, column chromatograph, and spin dry the solvent to obtain 33.9 g of white solid M3, with a yield of 76%.

[0089] (4) M3 (44.6 g, 0.1 mol) was added to a 1 L three-necked flask, and 200 mL of ethylene glycol ether (DEG) was added. The mixture was gradually heated to reflux under nitrogen protection, and the solid gradually dissolved. The mixture was stirred magnetically and kept warm for 3 hours to terminate the reaction. The organic phase was separated, extracted, dried, column chromatographed, and the solvent was dried to obtain 34.7 g of light pink solid M4, with a yield of 81%.

[0090] (5) Under nitrogen protection, M4 (42.8 g, 0.1 mol) and anhydrous THF 800 mL were added to a 2L three-necked flask, cooled to -78°C, and 2.5 M n-butyl lithium n-hexane solution (100 mL, 0.25 mol) was slowly added dropwise under stirring for about 30 mins. After the addition was completed, the dropping funnel was rinsed with 50 mL of anhydrous THF, and the reaction solution of M5 was obtained after the addition was completed for 1.5 hours. In a low temperature system of -78°C, sulfur dichloride (16 mL, 0.25 mol) was slowly added dropwise, and then the dropping funnel was rinsed with a small amount of anhydrous THF. After the addition was completed, the reaction solution was kept for 1 hour, and then the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 4 hours, and the reaction was completed. The mixture was adjusted to neutral, the organic phase was separated, extracted, dried, column chromatographed, and the solvent was spin-dried to obtain 26.6 g of white solid P1, with a yield of 58%.

[0091] Product MS (m / e): 300.07; Elemental analysis (C 19 H 12 N 2 S): Theoretical value C: 75.97%, H: 4.03%, N: 9.33%; Measured value C: 76.08%, H: 4.11%, N: 9.16%.

[0092] 1 HNMR (500MHz, CDCl 3 )δ:8.16(dd,J=7.4,1.2Hz,1H),7.73(dd,J=6.4,1.6Hz,1H),7.75(dd,J=7.1,1.6Hz,1H),7.63–7.54(m,2H),7.47-7.25(m,7H).

[0093] Example 2 Synthesis of Compound III-1

[0094]

[0095] The reaction formula is as follows:

[0096]

[0097] The specific experimental steps are:

[0098] (1) In a 500 mL three-necked flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen protection device, add the following in sequence: ligand P1 (25 mmmol, 7.5 g), iridium trichloride hydrate (10 mmol, 3.35 g), ethylene glycol monoethyl ether 90 mL, and distilled water 30 mL. Evacuate the flask and fill it with nitrogen. 2, repeat 5 times to remove oxygen in the system. Heat to 110℃ and reflux for 24 hours. After natural cooling, add 10mL of distilled water, shake, filter, wash with water, and wash with ethanol. Vacuum dry to obtain 5.9g of crude dichloro-bridged intermediate M6 as a yellow solid.

[0099] (2) In a 250 ml three-necked flask equipped with a magnetic stirrer and a reflux condenser, the intermediate M6 (5 mmol, 8.3 g), acetylacetone (25 mmol, 2.5 g, 2.6 mL), anhydrous Na 2 CO 3 (22mmol, 2.35g) and 100mL of ethylene glycol monoethyl ether. Vacuum and fill with N 2 , repeat 5 times to remove oxygen from the system. 2 Heat under reflux at 120°C oil bath for 24 hours under protection. Cool naturally to room temperature, filter, wash with water, n-hexane, and ether in sequence, and dry to obtain a yellow crude product. 2 Cl 2 Dissolve and separate on column, eluent CH 2 Cl 2 , drain the solvent and obtain 7.4 grams of yellow powder.

[0100] Product MS (m / e): 890; Elemental analysis (C 43 H 29 Ir 4 O 2 S 2 ): Theoretical value C: 58.03%, H: 3.28%, N: 6.29%; Measured value C: 58.01%, H: 3.32%, N: 6.40%. The H NMR spectrum of the product compound III-1 is shown in Figure 1 .

[0101] Example 3 Synthesis of Compound III-2

[0102]

[0103] Using 3,7-diethylnonane-4,6-dione instead of acetylacetone, the other raw materials and steps are the same as those in Example 1 to synthesize compound III-2.

[0104] Product MS (m / e): 1002.55; Elemental analysis (C 51 H 45 Ir 4 O 2 S 2 ): Theoretical value C: 61.12%, H: 4.53%, N: 5.59%; Measured value C: 61.22%, H: 4.48%, N: 5.63%. The H NMR spectrum of the product compound III-2 is shown in Figure 2 .

[0105] Example 4 Synthesis of Compound III-3

[0106]

[0107] Using 2,2,6,6-tetramethylheptane-3,5-dione instead of acetylacetone, the other raw materials and steps are the same as those in Example 1 to synthesize compound III-3.

[0108] Product MS (m / e): 974.62; Elemental analysis (C 49 H 41 Ir 4 O 2 S 2 ): Theoretical value C: 60.41%, H: 4.24%, N: 5.75%; Measured value C: 60.52%, H: 4.16%, N: 5.69%. The H NMR spectrum of the product compound III-3 is shown in Figure 3 .

[0109] Example 5 Synthesis of Compound II-2

[0110]

[0111] The reaction formula is as follows:

[0112]

[0113] The specific experimental steps are:

[0114] (1) In a 100 mL three-necked flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen protection device, add phenylpyridine (15 mmol, 2.5 mL), iridium trichloride hydrate (6 mmol, 2.01 g), ethylene glycol monoethyl ether 45 mL and distilled water 15 mL in sequence. Evacuate the flask and fill it with N 2 , repeat five times to remove oxygen from the system. Heat to 110℃ and reflux for 24 hours. After natural cooling, add 10mL of distilled water, shake, filter, wash with water, and wash with ethanol. Vacuum dry to obtain 2.6g of crude dichloro-bridged intermediate M7 as a yellow solid.

[0115] (2) In a 500 mL three-necked flask equipped with a nitrogen protection device, add the dichloro bridged intermediate M7 (10.7 g, 10 mmol) and 150 ml of dichloromethane in sequence, stir well, then add a 200 ml methanol solution of silver trifluoromethanesulfonate (6.4 g, 25 mmol), stir for 24 hours under light-proof conditions, cool to room temperature, filter out the generated AgCl with diatomaceous earth, and spin dry the filtrate to obtain a yellowish brown solid powder. This solid is used directly in the next step without treatment.

[0116] (3) In a 250 ml three-necked flask, add the khaki solid (5.1 g, 6.9 mmol) obtained in step (2) above and ligand P1 (6 g, 21 mmol), then add 100 ml of ethanol, heat the mixture under reflux for 36 hours, cool the reactants to room temperature, filter the generated yellow solid, dissolve the solid in dichloromethane, and separate by column chromatography to obtain 10.2 g of a bright yellow solid.

[0117] Product MS (m / e): 800; Elemental analysis (C 41 H 27 Ir 4 S): Theoretical value C: 61.56%, H: 3.40%, N: 7.00%; Measured value C: 61.61%, H: 3.46%, N: 7.05%. The H NMR spectrum of the product compound II-2 is shown in Figure 4 .

[0118] Example 6 Synthesis of Compound I-1

[0119]

[0120] The reaction formula is as follows:

[0121]

[0122] The specific experimental steps are as follows: In a 250ml three-necked flask equipped with a magnetic stirrer and a reflux condenser, add Ir(acac) 3 (10mmol, 4.9g), ligand P1 (40mmol, 12g), 150mL glycerol. Vacuum and fill with N 2 , repeat 5 times to remove oxygen from the system. 2 Heat under reflux at 190℃ oil bath for 24 hours under protection. Cool naturally to room temperature, filter, wash with water, n-hexane and ether in sequence, and dry to obtain a yellow crude product. 2 Cl 2 Dissolve and separate on column, eluent CH 2 Cl 2 , the solvent was drained off to obtain 4.5 g of yellow powder with a yield of 41%.

[0123] Product MS (m / e): 1090; Elemental analysis (C 57 H 33 Ir 6 S 3 ): Theoretical value C: 62.79%, H: 3.05%, N: 7.71%; Measured value C: 62.85%, H: 3.11%, N: 7.64%.

[0124] Referring to the above synthesis method, compounds II-18, II-20 and compound I-6 were synthesized.

[0125] Other specific compounds in the present invention can be synthesized by referring to the preparation method disclosed in the patent application with publication number CN 112175016 A.

[0126] Those skilled in the art should be aware that the above preparation method is only an illustrative example, and those skilled in the art can obtain other compound structures of the present invention by improving it.

[0127] Device Examples 1-10

[0128] Several specific embodiments of the device are provided below. The present invention does not specifically limit the method for making the organic electroluminescent device. The preparation method of the following embodiment is only an example and should not be construed as limiting. Those skilled in the art can reasonably improve the preparation method of the following embodiment based on the prior art.

[0129] Device Example 1

[0130] This embodiment provides an organic electroluminescent device, and the preparation process is as follows:

[0131] First, the glass substrate with a 120nm thick indium tin oxide (ITO) anode was cleaned and treated with UV ozone and oxygen plasma. After treatment, the substrate was dried in a nitrogen-filled glove box to remove moisture, and then the substrate was mounted on a substrate holder and loaded into a vacuum chamber.

[0132] The organic layer is then evaporated, and the organic layer is specified below, at a vacuum of about 10 -8 Torr's case The rate of evaporation is carried out on the ITO anode in turn by thermal vacuum;

[0133] Compound HT and NDP-9 were sequentially deposited simultaneously as a hole injection layer (HIL) with a thickness of

[0134] Compound HT was used as a hole transport layer (HTL) with a thickness of

[0135] The compound TAPC is used as an electron blocking layer (EBL) with a thickness of

[0136] DIC-TRZ as the host compound, compound III-1 as the first dopant, and compound III-2 as the second dopant were co-evaporated to form an emitting layer (EML) with a thickness of The main compound DIC-TRZ accounts for 94% of the total weight of the light-emitting layer, the compound III-1 accounts for 3% of the total weight of the light-emitting layer, and the compound III-2 accounts for 3% of the total weight of the light-emitting layer; the difference in evaporation temperature between the compound III-1 and the compound III-2 during the device preparation process should be less than 15°C, preferably the difference in evaporation temperature is less than 5°C;

[0137] The compound TPBI was used as the hole blocking layer (HBL) with a thickness of

[0138] On the hole blocking layer, compound ET01 and 8-hydroxyquinoline-lithium (Liq) were co-evaporated as an electron transport layer (ETL) with a thickness of The compounds ET01 and Liq each account for 50% of the total weight of the electron transport layer;

[0139] Finally, evaporation LiF with a thickness of 1000 mm was used as an electron injection layer (EIL), and the of aluminum as cathode.

[0140] The device was then transferred back to the glove box and encapsulated with a glass lid to complete the device.

[0141] Device Example 2

[0142] Device Example 2 was prepared with reference to Device Example 1, except that in the light-emitting layer (EML), the weight of compound III-2 was changed from 3% to 6%, and the weight of the main compound DIC-TRZ was changed from 94% to 91%.

[0143] Device Example 3

[0144] Device Example 3 was prepared with reference to Device Example 1, with the only difference being that in the light-emitting layer (EML), the weight of compound III-1 was changed from 3% to 1%, the weight of compound III-2 was changed from 3% to 4%, and the weight of the main compound DIC-TRZ was changed from 94% to 95%.

[0145] Device Example 4

[0146] Device Example 4 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-2 was replaced by Compound III-3.

[0147] Device Example 5

[0148] Device Example 5 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-1 was replaced by Compound III-3.

[0149] Device Example 6

[0150] Device Example 6 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-2 was replaced by Compound II-2.

[0151] Device Example 7

[0152] Device Example 7 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-2 was replaced by Compound I-1.

[0153] Device Example 8

[0154] Device Example 8 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-1 was replaced by II-2, and Compound III-2 was replaced by II-18.

[0155] Device Example 9

[0156] Device Example 9 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-1 was replaced by II-2, and Compound III-2 was replaced by II-20.

[0157] Device Example 10

[0158] Device Example 10 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), Compound III-1 was replaced by I-1, and Compound III-2 was replaced by I-6.

[0159] Device Comparison Example 1

[0160] Device Comparative Example 1 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), the second dopant compound III-2 was replaced by III-1.

[0161] Device Comparison Example 2

[0162] Device Comparative Example 2 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), the first dopant compound III-1 and the second dopant compound III-2 were both replaced by II-2.

[0163] Device Comparison Example 3

[0164] Device Comparative Example 3 was prepared with reference to Device Example 1, except that in the light emitting layer (EML), the first dopant compound III-1 and the second dopant compound III-2 were both replaced by I-1.

[0165] The detailed device layer structures and thicknesses of the above device embodiments and comparative examples are shown in Table 1. Where more than one material is used, different compounds are doped in the weight ratios listed in Table 1.

[0166] Table 1 Device structures of device embodiments and comparative examples

[0167]

[0168]

[0169] The material structure used in the above devices is as follows:

[0170]

[0171] The performance of the device examples and comparative examples prepared above was tested. Table 2 lists the performance of the device examples and comparative examples prepared above at 20 mA / cm 2 Under the conditions, the voltage (Voltage, V), current efficiency (CE) and device life (LT) of device embodiments 1-9 and device comparative examples 1-3 were measured. 97 )Test results.

[0172] Table 2 Device performance test data

[0173]

[0174]

[0175] Through the detection data of the above devices, we can find that: compared with device comparison examples 1 to 3, device embodiments 1 to 10, that is, the light-emitting layer is co-doped with multiple guest light-emitting materials compared with the use of a single light-emitting material doping, whether it is voltage, current efficiency or life, the use of two metal complexes as dopants is significantly improved compared with the use of a single metal complex as a dopant. The prepared organic electroluminescent device can obtain lower voltage, higher luminous efficiency and longer life, which can significantly improve the performance of the device and bring unexpected effects to the device performance.

[0176] From the device data of Examples 1 to 3, it can be seen that the performance of the obtained device also changes significantly when the ratio of the two metal complex dopants in the light-emitting layer to the total weight of the light-emitting layer and the mass ratio of the two metal complex dopants are changed. When the mass ratio of the two metal complex dopants is 1:1 and the two metal complex dopants account for 6% of the total weight of the light-emitting layer, the device voltage is the smallest, the current efficiency is the largest, and the life is the longest.

[0177] By comparing the device test data of Examples 1, 4-5, 8-10 and Examples 6-7, it can be seen that the more similar the compound structures of the two metal complex dopants are, the better the performance of the device prepared by using them as the doping material for the light-emitting layer, especially Examples 8 and 9, whose current efficiency is significantly improved and the lifespan is unexpectedly improved.

[0178] In summary, the present invention combines the first metal complex and the second metal complex. Since the two compounds can be well matched with each other in energy, the device exhibits excellent comprehensive device performance, has a lower driving voltage, higher efficiency and an ultra-long device life.

[0179] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. An organic electroluminescent material, characterized in that: comprising a first compound and a second compound, Wherein, the first compound and the second compound are both selected from the compounds represented by the general formula I, or are both selected from the compounds represented by the general formula II, or are both selected from the compounds represented by the general formula III, and the first compound and the second compound are different; Where m is 1 or 2, The R 1 ~R 11 are independently selected from a hydrogen atom, a deuterium atom, a C1-C5 alkyl group, and a C1-C5 deuterated alkyl group, The R 12 ~R 19 are independently selected from a hydrogen atom, a deuterium atom, a C1-C5 alkyl group, and a C1-C5 deuterated alkyl group, The R 20 ~R 26 are independently selected from a hydrogen atom, a deuterium atom, a C1-C5 alkyl group, and a C1-C5 deuterated alkyl group; The mixing mass ratio of the first compound to the second compound is between 1:99 and 99:

1.

2. The luminescent material according to claim 1, characterized in that The R 1 ~R 11 are independently and arbitrarily selected from a hydrogen atom, a deuterium atom, a methyl group, a deuterated methyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a deuterated isopropyl group, a pentyl group, a deuterated pentyl group; and / or, The R 12 ~R 19 are independently selected from a hydrogen atom, a deuterium atom, a methyl group, a deuterated methyl group, an isopropyl group, and a deuterated isopropyl group; and / or, The R 20 ~R 26 Each is independently arbitrarily selected from a hydrogen atom, a deuterium atom, a methyl group and an ethyl group.

3. The luminescent material according to claim 1, characterized in that The first compound and the second compound are independently selected from the compounds represented by the following structural formulas, and the first compound and the second compound are different; 4. The luminescent material according to claim 3, characterized in that The first compound and the second compound are independently selected from the compounds shown in I-1 to I-7, I-12 to I-16, and I-26 to I-28, and the first compound and the second compound are different; Alternatively, the first compound and the second compound are independently selected from compounds shown in II-1 to II-5, II-7, II-10, II-18, II-20 to II-23, and II-25, and the first compound and the second compound are different; Alternatively, the first compound and the second compound are independently selected from the compounds shown in III-1 to III-6, and the first compound and the second compound are different.

5. The luminescent material according to any one of claims 1 to 4, characterized in that: The mixing mass ratio of the first compound to the second compound is between 1:4 and 5:

1.

6. The luminescent material according to any one of claims 1 to 4, characterized in that: The mixing mass ratio of the first compound to the second compound is between 1:4 and 4:

1.

7. Use of the luminescent material according to any one of claims 1 to 6 in the preparation of an organic electroluminescent device.

8. The use according to claim 7, characterized in that: The light-emitting material is used as a doping material for a light-emitting layer in an organic electroluminescent device.

9. The use according to claim 7 or 8, characterized in that: The luminescent material accounts for 4% to 20% of the total mass of the luminescent layer.

10. The use according to claim 9, characterized in that: The luminescent material accounts for 4% to 10% of the total mass of the luminescent layer.

11. An organic electroluminescent device comprising the luminescent material according to any one of claims 1 to 6, characterized in that: include: anode, cathode, and an organic layer disposed between an anode and a cathode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the light-emitting material according to any one of claims 1 to 6.

12. The organic electroluminescent device according to claim 11, characterized in that: The light-emitting layer comprises a host material and a dye material, and the dye material comprises the light-emitting material according to any one of claims 1 to 6.

13. The organic electroluminescent device according to claim 11 or 12, characterized in that: The doping concentration of the luminescent material according to any one of claims 1 to 6 in the luminescent layer is 4 to 20%.

14. The organic electroluminescent device according to claim 13, characterized in that: The doping concentration of the luminescent material in the luminescent layer is 4-10%.

15. The organic electroluminescent device according to claim 13, characterized in that: The doping concentration of the luminescent material in the luminescent layer is 5-9%.

16. The organic electroluminescent device according to claim 11, characterized in that: The host material comprises at least one chemical group selected from the group consisting of benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolecarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silylfluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

17. A display component, characterized in that: An organic electroluminescent device comprising any one of claims 11-16.

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