An organic electroluminescent device

Abstract

The invention discloses an organic electroluminescent device, belonging to the technical field of optoelectronic devices, comprising a substrate, a first electrode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic electroluminescent layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode which are arranged in sequence; the organic electroluminescent layer comprises a main material and a luminescent material, and the doping material in the luminescent material has a compound with a structure shown in the following formula RD: the luminescent layer of the organic electroluminescent device of the invention adopts a structure composed of a specific doping material and a specific main material, and cooperates with other layer materials to enable the obtained organic electroluminescent device to effectively reduce the starting and falling voltage, improve the current efficiency, and improve the problem of low lifespan.

Description

Technical Field

[0001] The invention relates to the technical field of optoelectronic devices, in particular to an organic electroluminescent device. Background Art

[0002] As a new generation of display technology, organic electroluminescent materials (OLEDs) have the advantages of ultra-thinness, self-luminescence, wide viewing angle, fast response, high luminous efficiency, good temperature adaptability, simple production process, low driving voltage and low energy consumption. They have been widely used in industries such as flat panel displays, flexible displays, solid-state lighting and automotive displays.

[0003] Since the first report of high-efficiency organic light-emitting diodes, the industry has been committed to studying how to improve the efficiency and stability of devices. Phosphorescent materials have strong spin-orbit coupling and can use singlet and triplet excitons at the same time, so that the quantum efficiency of phosphorescent electroluminescent devices can reach 100% in theory. However, the excited state lifetime of phosphorescent materials is long. When the concentration of triplet excitons is high, triplet-triplet annihilation and triplet-polaron annihilation are easily formed, which seriously reduces the efficiency. Therefore, phosphorescent materials are often doped into host materials as guests to reduce the self-concentration quenching process.

[0004] At present, OLED display and lighting have been widely used in commercial applications, and the photoelectric requirements of OLED screens by customer terminals are constantly increasing. In order to meet such demands, in addition to the continuous improvement of OLED panel manufacturing technology, the development of OLED materials that can meet higher device indicators is particularly important. Therefore, the development of stable and efficient luminescent materials, thereby reducing the driving voltage and improving the luminous efficiency and life of the device, will have very important practical application value. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide an organic electroluminescent device. The organic electroluminescent device provided by the present invention adopts a doping material and a host material of a specific structure, so that after the obtained organic compound is used in the organic electroluminescent device, the starting voltage of the device is reduced and the luminous efficiency and life of the device are improved.

[0006] To achieve the aforementioned object of the present invention, the present invention provides an organic electroluminescent device, comprising a substrate, a first electrode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic electroluminescent layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode arranged in sequence.

[0007] The organic electroluminescent layer includes luminescent dyes (i.e., dopants) that can emit different wavelength spectra, and can also include a host material (Host); the luminescent layer can be a monochromatic luminescent layer that emits a single color such as red, green, and blue. Multiple monochromatic luminescent layers of different colors can be arranged in a plane according to a pixel pattern, or they can be stacked together to form a color luminescent layer; when luminescent layers of different colors are stacked together, they can be separated from each other or connected to each other. The luminescent layer can also be a single color luminescent layer that can simultaneously emit different colors such as red and green.

[0008] Depending on different technologies, the light-emitting layer material can be made of different materials such as phosphorescent electroluminescent materials and thermally activated delayed fluorescent materials; in an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used; these different light-emitting materials classified by technology can emit light of the same color or different colors.

[0009] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology; preferably, the doping material in the organic electroluminescent layer has any one of the compounds with the structure shown in the following formula RD:

[0010]

[0011] in,

[0012] A is selected from one of the following structures A-1 to A-22:

[0013]

[0014]

[0015] in,

[0016] q is an integer between 1 and 10;

[0017] * is the connection key;

[0018] X is selected from one of C and Si;

[0019] Y is selected from one of O and S;

[0020] R1 and R2 are each independently selected from one of D, -CH3, -CD3, and -CH2CH3;

[0021] R4-R7 and Ar1 are each independently selected from any one of -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, substituted or unsubstituted C2-C6 alkyl, substituted or unsubstituted C6-C10 aryl and substituted or unsubstituted 4-8 membered aromatic heterocyclic group, and two adjacent substituents of R4-R7 form a C4-C12 aromatic ring or aromatic heterocyclic ring.

[0022] As a further technical solution of the present invention: the alkyl groups in R4-R7 and Ar1 are independently selected from any one of substituted or unsubstituted straight-chain alkyl groups, substituted or unsubstituted branched-chain alkyl groups and substituted or unsubstituted cycloalkyl groups.

[0023] As a further technical solution of the present invention: the heteroatoms in the heteroaryl groups in R4-R7 and Ar1 are each independently selected from at least one of N, S and O.

[0024] As a further technical solution of the present invention: a benzene ring is formed between two adjacent substituents of R4-R7.

[0025] As a further technical solution of the present invention: the doping material is selected from one of the following structures:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] As a further technical solution of the present invention: the synthesis route of the compound of the structure shown in formula RD is as follows:

[0033]

[0034] The definitions in the above formula are consistent with those mentioned above and will not be repeated here.

[0035] As a further technical solution of the present invention: the main material has a compound having a structure shown in the following formula RH:

[0036]

[0037] in,

[0038] The L is selected from a connecting bond, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 6-30 membered aromatic heterocyclic group;

[0039] The Ar2 has the following structure:

[0040]

[0041] in,

[0042] Said is the connection location;

[0043] The R7 and R8 are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 6-30 membered aromatic heterocyclic group, substituted or unsubstituted C10-C30 fused ring group, substituted or unsubstituted C5-C30 spiro ring.

[0044] As a further technical solution of the present invention: the main material is selected from one of the following structural compounds:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] As a further technical solution of the present invention: the synthesis route of the compound of the structure represented by the formula RH is as follows:

[0051]

[0052] Wherein, P represents halogen, specifically F, Cl, Br and I. The remaining definitions in the above formula are consistent with the above and will not be repeated here.

[0053] Generally speaking, an organic electroluminescent device includes a first electrode, a second electrode, and an organic material layer between the electrodes; the organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0054] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0055] The first electrode can be formed by sputtering or depositing a material used as the first electrode on a substrate. When the first electrode is used as an anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. In addition, the anode material can also be selected from materials and combinations thereof that facilitate hole injection other than the listed anode materials, including materials known to be suitable for anodes. When the first electrode is used as a cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used. In addition to the cathode materials listed above, the cathode material can also be a material and a combination thereof that facilitates electron injection, including materials known to be suitable for cathodes.

[0056] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing and the like. The compound used as the organic material layer can be an organic small molecule, an organic macromolecule and a polymer, and a combination thereof. The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a hole transport layer (HTL) of a single-layer structure, including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0057] The material of the hole transport layer can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene vinylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-34 below, or any combination thereof:

[0058]

[0059] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-34 mentioned above, or one or more compounds of HI1-HI3 below; or one or more compounds of HT-1 to HT-34 can be doped with one or more compounds of HI1-HI3 below:

[0060]

[0061] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0062] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-57 listed below:

[0063]

[0064]

[0065] The device may also include an electron injection layer located between the electron transport layer and the cathode. The electron injection layer material includes but is not limited to one or more combinations of the following: LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0066] Compared with the prior art, the beneficial effects of the present invention are as follows: the light-emitting layer of the organic electroluminescent device of the present invention adopts a structure composed of a specific doping material and a specific main material, and in combination with other layer materials, the obtained organic electroluminescent device can effectively reduce the starting and dropping voltage, improve the current efficiency, and improve the problem of low life. DETAILED DESCRIPTION

[0067] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0068] Synthesis example 1

[0069] An organometallic compound RD002, i.e. a compound numbered RD002, has a synthesis route as follows:

[0070]

[0071] The specific synthesis steps are as follows:

[0072] Under nitrogen protection system, weigh ligand RDⅠ-002 (13.8 g, 50 mmol), IrC 133H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 390 ml of ethylene glycol ethyl ether and 130 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-002 with a mass of 8.9 g and a yield of 52%;

[0073] Weigh the bridging ligand RDⅡ-002 (8.54 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 170 ml of ethylene glycol ethyl ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (4.43 g, 16.5 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD002, with a mass of 4.0 g and a yield of 36%.

[0074] The organometallic compound L002 was subjected to the following analytical tests:

[0075] HPLC purity: greater than 99.5%;

[0076] Mass spectrum: calculated value is 1009.43; tested value is 1009.40;

[0077] PL test value: 626.8nm.

[0078] Synthesis example 2

[0079] This synthesis example provides an organometallic compound RD021, that is, a compound numbered RD021, and the synthesis route is as follows:

[0080]

[0081] The specific synthesis steps are as follows:

[0082] Under nitrogen protection system, weigh the ligand 2-phenylpyrrolidone (7.45 g, 48 mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 450 ml of ethylene glycol ethyl ether and 150 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-021 with a mass of 6.13 g and a yield of 52%;

[0083] Weigh the bridging ligand RDⅡ-021 (5.90 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 170 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (4.43 g, 16.5 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD021, with a mass of 2.37 g and a yield of 28%.

[0084] The organometallic compound RD021 was subjected to the following analytical tests:

[0085] HPLC purity: greater than 99.5%;

[0086] Mass spectrum: calculated value is 769.04; tested value is 769.10;

[0087] PL test value: 526.4nm.

[0088] Synthesis example 3

[0089] This synthesis example provides an organometallic compound RD049, that is, a compound numbered RD049, and the synthesis route is as follows:

[0090]

[0091] The specific synthesis steps are as follows:

[0092] Under nitrogen protection system, weigh ligand RDⅠ-049 (15.67 g, 52 mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 480 ml of ethylene glycol ethyl ether and 160 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-049 with a mass of 10.57 g and a yield of 58%;

[0093] Weigh the bridging ligand RDⅡ-049 (9.1 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (5.37 g, 20 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD049, with a mass of 3.97 g and a yield of 34%.

[0094] The organometallic compound RD049 was subjected to the following analytical tests:

[0095] HPLC purity: greater than 99.5%;

[0096] Mass spectrum: calculated value is 1061.37; tested value is 1061.40;

[0097] PL test value: 614.0nm.

[0098] Synthesis example 4

[0099] This synthesis example provides an organometallic compound RD052, that is, a compound numbered RD052, and the synthesis route is as follows:

[0100]

[0101] The specific synthesis steps are as follows:

[0102] Under nitrogen protection system, RDⅠ-052 (15.37 g, 50 mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 450 ml of ethylene glycol ethyl ether and 150 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-052 with a mass of 11.65 g and a yield of 63%;

[0103] Weigh the bridging ligand RDⅡ-052 (9.25 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (5.37 g, 20 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD052, with a mass of 2.48 g and a yield of 21%.

[0104] The following analytical tests were performed on organometallic compounds RD052:

[0105] HPLC purity: greater than 99.5%;

[0106] Mass spectrum: calculated value is 1073.44; tested value is 1073.50;

[0107] PL test value: 615.2nm.

[0108] Synthesis example 5

[0109] This synthesis example provides an organometallic compound RD074, that is, a compound numbered RD074, and the synthesis route is as follows:

[0110]

[0111] The specific synthesis steps are as follows:

[0112] Under nitrogen protection system, weigh ligand RDⅠ-074 (17.22 g, 49 mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 510 ml of ethylene glycol ethyl ether and 170 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-074 with a mass of 10.84 g and a yield of 53%;

[0113] Weigh the bridging ligand RDⅡ-074 (10.22 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (4.43 g, 16.5 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD074, with a mass of 3.96 g and a yield of 31%.

[0114] The organometallic compound RD074 was subjected to the following analytical tests:

[0115] HPLC purity: greater than 99.5%;

[0116] Mass spectrum: calculated value is 1161.39; tested value is 1161.40;

[0117] PL test value: 620.7nm.

[0118] Synthesis example 6

[0119] This synthesis example provides an organometallic compound RD081, that is, a compound numbered RD081, and the synthesis route is as follows:

[0120]

[0121] The specific synthesis steps are as follows:

[0122] Under nitrogen protection system, weigh ligand RDⅠ-081 (14.47 g, 48 mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 450 ml of ethylene glycol ethyl ether and 150 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-081 with a mass of 9.84 g and a yield of 54%;

[0123] Weigh the bridging ligand RDⅡ-081 (9.1 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ethyl ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (5.37 g, 20 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD081, with a mass of 4.44 g and a yield of 38%.

[0124] The organometallic compound RD081 was subjected to the following analytical tests:

[0125] HPLC purity: greater than 99.5%;

[0126] Mass spectrum: calculated value is 1061.37; tested value is 1061.40;

[0127] PL test value: 617.8nm.

[0128] Synthesis Example 7

[0129] This synthesis example provides an organometallic compound RD095, that is, a compound numbered RD095, and the synthesis route is as follows:

[0130]

[0131] The specific synthesis steps are as follows:

[0132] Under nitrogen protection system, weigh the ligand RDⅠ-095 [4-(3,5-dimethylphenyl)-9-fluorobenzo[f]isoquinoline (16.57 g, 55 mmol)], IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 480 ml of ethylene glycol ethyl ether and 160 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-095 with a mass of 10.57 g and a yield of 58%;

[0133] Weigh the bridging ligand RDⅡ-095 (9.1 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (5.91 g, 22 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD095, with a mass of 4.09 g and a yield of 35%.

[0134] The organometallic compound RD095 was subjected to the following analytical tests:

[0135] HPLC purity: greater than 99.5%;

[0136] Mass spectrum: calculated value is 1061.37; tested value is 1061.40;

[0137] PL test value: 620.4nm.

[0138] Synthesis example 8

[0139] This synthesis example provides an organometallic compound RD142, that is, a compound numbered RD142, and the synthesis route is as follows:

[0140]

[0141] The specific synthesis steps are as follows:

[0142] Under nitrogen protection, weigh the ligand RDⅠ-142{1-(3,5-dimethylphenyl)-7-fluorobenzo[h]isoquinoline}(16.57g, 55mmol), IrC 13 3H20 (7.76 g, 22 mmol) was placed in the reaction system, and a mixed solution of 480 ml of ethylene glycol ethyl ether and 160 ml of pure water was added. The mixture was refluxed for 26 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand RDⅡ-142 with a mass of 10.93 g and a yield of 60%;

[0143] Weigh the bridging ligand RDⅡ-142 (9.1 g, 5.5 mmol), add anhydrous potassium carbonate (7.59 g, 55 mmol), then add 180 ml of ethylene glycol ether to the system, replace nitrogen three times, add 4,8-diethyl-2,10-dimethylundecane-5,7-dione (5.37 g, 20 mmol) under nitrogen, reflux for 22 hours under nitrogen protection, cool, filter, wash with alcohol, and dry; use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material shown in RD142, with a mass of 3.50 g and a yield of 30%.

[0144] The organometallic compound RD142 was subjected to the following analytical tests:

[0145] HPLC purity: greater than 99.5%;

[0146] Mass spectrum: calculated value is 1061.37; tested value is 1061.40;

[0147] PL test value: 628.1nm.

[0148] Synthesis example 9

[0149] This synthesis example provides an organometallic compound RH-1, that is, a compound numbered RH-1, and the synthesis route is as follows:

[0150]

[0151] The specific synthesis steps are as follows:

[0152] Under nitrogen protection, RHⅠ-1 (20mmol, 7.77g), RHⅡ-1 (28mmol, 9.25g), sodium tert-butoxide (56mmol, 5.38g) were weighed and put into the reaction system, 150ml of toluene was added, catalyst Pd2(dba)3 (0.6mmol, 0.55g) and P(t-Bu)3 (1.2mmol, 0.24g) were added under nitrogen protection, refluxed at 110℃ for 24h, and then cooled to 25 ℃, the organic phase was passed through a silica gel funnel containing 200g silica gel, the organic phase filtrate was vortexed until no liquid flowed out, 100ml of dichloromethane was added to dissolve, the solution was column chromatographed (200-300 mesh, 400g) with a developing agent of DCM:PE=3:1, the receiving liquid was vortexed until no liquid flowed out, petroleum ether was added and stirred for 20min, filtered, the filter cake was rinsed with petroleum ether, and the filter cake was vacuum dried to obtain the compound formula RH-1 (8.29g, yield 65%), and its HPLC purity was greater than 99.5%.

[0153] Mass spectrum: calculated value: 637.75; tested value: 637.22.

[0154] Elemental Analysis:

[0155] Calculated values ​​C: 84.75; H: 4.27; N: 10.98;

[0156] The test values ​​are C: 84.78; H: 4.25; N: 10.97.

[0157] Synthesis example 10

[0158] This synthesis example provides an organometallic compound RH-21, that is, a compound numbered RH-21, and the synthesis route is as follows:

[0159]

[0160] The specific synthesis steps are as follows:

[0161] Under nitrogen protection, RHⅠ-21 (20mmol, 8.88g), RHⅡ-21 (30mmol, 9.91g), sodium tert-butoxide (60mmol, 5.77g) were weighed and put into the reaction system, 190ml toluene was added, catalyst Pd2(dba)3 (0.8mmol, 0.73g) and P(t-Bu)3 (1.6mmol, 0.32g) were added under nitrogen protection, refluxed at 110℃ for 24h, and then cooled to 25 ℃, the organic phase was passed through a silica gel funnel containing 200g of silica gel, the organic phase filtrate was vortexed until no liquid flowed out, 100ml of dichloromethane was added to dissolve, the solution was subjected to column chromatography (200-300 mesh, 400g) with a developing agent of DCM:PE=3:1, the receiving solution was vortexed until no liquid flowed out, petroleum ether was added and stirred for 20min, filtered, the filter cake was rinsed with petroleum ether, and the filter cake was vacuum dried to obtain the compound RH-21 (10.63g, yield 72%), with an HPLC purity of greater than 99.5%.

[0162] Mass spectrum: calculated value: 737.87; tested value: 737.61.

[0163] Elemental Analysis:

[0164] Calculated value C: 86.27; H: 4.23; N: 9.49;

[0165] The test values ​​are C: 86.25; H: 4.25; N: 9.49.

[0166] Synthesis example 11

[0167] This synthesis example provides an organometallic compound RH-31, that is, a compound numbered RH-31, and the synthesis route is as follows:

[0168]

[0169] The specific synthesis steps are as follows:

[0170] Under nitrogen protection, RHⅠ-31 (20mmol, 12.33g), RHⅡ-31 (24mmol, 7.93g), sodium tert-butoxide (60mmol, 5.77g) were weighed and put into the reaction system, 250ml of toluene, catalyst Pd2(dba)3 (0.6mmol, 0.55g) and P(t-Bu)3 (1.2mmol, 0.24g) were added under nitrogen protection, refluxed at 110℃ for 24h, and then cooled to 25 ℃, the organic phase was passed through a silica gel funnel containing 200g of silica gel, the organic phase filtrate was vortexed until no liquid flowed out, 100ml of dichloromethane was added to dissolve, the solution was column chromatographed (200-300 mesh, 400g) with a developing agent of DCM:PE=3:1, the receiving liquid was vortexed until no liquid flowed out, petroleum ether was added and stirred for 20min, filtered, the filter cake was rinsed with petroleum ether, and the filter cake was vacuum dried to obtain the compound RH-31 (13.16g, yield 76%), with an HPLC purity of more than 99.5%.

[0171] Mass spectrum: calculated value 866.04: tested value 866.27.

[0172] Elemental analysis: calculated value C: 87.37; H: 4.54; N: 8.09;

[0173] The test values ​​are C: 87.38; H: 4.56; N: 8.06.

[0174] Synthesis example 12

[0175] This synthesis example provides an organometallic compound RH-86, that is, a compound numbered RH-86, and the synthesis route is as follows:

[0176]

[0177] The specific synthesis steps are as follows:

[0178] Under nitrogen protection, RHⅠ-86 (20mmol, 10.81g), RHⅡ-86 (22mmol, 7.27g), sodium tert-butoxide (60mmol, 5.77g) were weighed and put into the reaction system, 210ml toluene was added, catalyst Pd2(dba)3 (0.4mmol, 0.37g) and P(t-Bu)3 (0.8mmol, 0.16g) were added under nitrogen protection, refluxed at 110℃ for 24h, and then cooled to 25 ℃, pass the organic phase through a silica gel funnel containing 200g silica gel, vortex the organic phase filtrate until no liquid flows out, add 100ml of dichloromethane to dissolve, and perform column chromatography (200-300 mesh, 400g) with a developing agent of DCM:PE=3:1. Vortex the receiving solution until no liquid flows out, add petroleum ether and stir for 20min, filter with suction, rinse the filter cake with petroleum ether, and vacuum dry the filter cake to obtain the compound RH-86 (10.11g, yield 64%) with an HPLC purity of more than 99.5%.

[0179] Mass spectrum: calculated value: 789.94; tested value: 789.80.

[0180] Elemental Analysis:

[0181] Calculated values ​​C: 86.67; H: 4.47; N: 8.87;

[0182] The test values ​​are C: 86.68; H: 4.45; N: 8.88.

[0183] Synthesis example 13

[0184] This synthesis example provides an organometallic compound RH-110, that is, a compound numbered RH-110, and the synthesis route is as follows:

[0185]

[0186] The specific synthesis steps are as follows:

[0187] Under nitrogen protection, RHⅠ-110 (20mmol, 12.41g), RHⅡ-110 (26mmol, 8.59g), sodium tert-butoxide (60mmol, 5.77g) were weighed and put into the reaction system, 250ml of toluene, catalyst Pd2(dba)3 (0.6mmol, 0.55g) and P(t-Bu)3 (1.2mmol, 0.24g) were added under nitrogen protection, refluxed at 110℃ for 24h, and then cooled to 2 5°C, pass the organic phase through a silica gel funnel containing 200 g of silica gel, vortex the organic phase filtrate until no liquid flows out, add 100 ml of dichloromethane to dissolve, and perform column chromatography (200-300 mesh, 400 g) with a developing agent of DCM:PE=3:1. Vortex the receiving solution until no liquid flows out, add petroleum ether and stir for 20 min, filter with suction, rinse the filter cake with petroleum ether, and vacuum dry the filter cake to obtain the compound RH-110 (14.10 g, yield 81%) with an HPLC purity greater than 99.5%.

[0188] Mass spectrum: calculated value: 870.07; tested value: 870.22.

[0189] Elemental analysis: calculated value C: 86.97; H: 4.98; N: 8.05;

[0190] The test values ​​are C: 86.99; H: 4.94; N: 8.07.

[0191] The synthesis methods of other compounds are the same as above and will not be described in detail here.

[0192] The present invention also provides an organic electroluminescent device, which is made of the organic luminescent material, more specifically, made of an organic luminescent material of a chemical formula RD structure compound and a chemical formula RH structure compound. In order to further describe the present invention, more specific embodiments are listed below.

[0193] Example 1

[0194] The ITO glass substrate with a coating thickness of 150nm was cleaned twice in distilled water and ultrasonically washed for 30 minutes, and then repeatedly cleaned twice with distilled water and ultrasonically washed for 10 minutes. After the distilled water cleaning, ultrasonically washed with isopropyl alcohol, acetone, methanol and other solvents in sequence, and then dried and transferred to a plasma cleaning machine. The above substrate was washed for 5 minutes and sent to a vapor deposition machine. First, compound HT-12 is vacuum evaporated on ITO (anode) to form a hole injection layer with a thickness of 55 nm; compound HT-7 material is vacuum evaporated on the hole injection layer to form a hole transport layer with a thickness of 35 nm, and the evaporation rate is 0.1 nm / s; an electroluminescent layer is formed on the above-mentioned hole transport layer, and the specific operation is as follows: the main material formula RH-1 of the compound of the present invention as the light-emitting layer is placed in a small chamber of a vacuum vapor deposition device, and RD002 as a dopant is placed in another chamber of the vacuum vapor deposition device, and the two materials are evaporated at different rates at the same time, the concentration of RD002 is 6%, and the total evaporated film thickness is 40 nm; ET-5 is vacuum evaporated on the light-emitting layer to form an electron transport layer with a thickness of 20 nm, and the evaporation rate is 0.1 nm / s; LiF with a thickness of 0.5 nm is vacuum evaporated on the electron transport layer (ETL) as an electron injection layer, and on the electron injection layer, an Al layer with a thickness of 150 nm is vacuum evaporated as the cathode of the device.

[0195] Example 2

[0196] The method of the above-mentioned embodiment 1 is referred to, except that the main material RH-1 is replaced by RH-21.

[0197] Example 3

[0198] The method of the above embodiment 1 is referred to, the only difference being that the doping material RD002 is replaced by RD021.

[0199] Example 4

[0200] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD049.

[0201] Example 5

[0202] The method of the above embodiment 1 is referred to, the only difference being that the doping material RD002 is replaced by RD052.

[0203] Example 6

[0204] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD074.

[0205] Example 7

[0206] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD081.

[0207] Example 8

[0208] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD095.

[0209] Example 9

[0210] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD142.

[0211] Example 10

[0212] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD081, and the main material RH-1 is replaced by RH-31.

[0213] Embodiment 11

[0214] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD095, and the main material RH-1 is replaced by RH-86.

[0215] Example 12

[0216] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD142, and the main material RH-1 is replaced by RH-110.

[0217] Example 13

[0218] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD074, and the main material RH-1 is replaced by RH-110.

[0219] Embodiment 14

[0220] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD052, and the main material RH-1 is replaced by RH-86.

[0221] Embodiment 15

[0222] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD049, and the main material RH-1 is replaced by RH-31.

[0223] Example 16

[0224] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD081, and the main material RH-1 is replaced by RH-86.

[0225] Embodiment 17

[0226] The method of the above-mentioned embodiment 1 is referred to, except that the main material RH-1 is replaced by PRH-01.

[0227] Embodiment 18

[0228] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD049, and the main material RH-1 is replaced by PRH-02.

[0229] Embodiment 19

[0230] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD052, and the main material RH-1 is replaced by PRH-03.

[0231] Embodiment 20

[0232] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD074, and the main material RH-1 is replaced by PRH-04.

[0233] Embodiment 21

[0234] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD081, and the main material RH-1 is replaced by PRH-05.

[0235] Embodiment 22

[0236] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD095, and the main material RH-1 is replaced by PRH-06.

[0237] Embodiment 23

[0238] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by RD142, and the main material RH-1 is replaced by PRH-07.

[0239] Embodiment 24

[0240] The method of the above embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-01.

[0241] Embodiment 25

[0242] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-02, and the main material RH-1 is replaced by RH-21.

[0243] Embodiment 26

[0244] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-03, and the main material RH-1 is replaced by RH-31.

[0245] Embodiment 27

[0246] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-04, and the main material RH-1 is replaced by RH-86.

[0247] Embodiment 28

[0248] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-05, and the main material RH-1 is replaced by RH-104.

[0249] Embodiment 29

[0250] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-06, and the main material RH-1 is replaced by RH-110.

[0251] Embodiment 30

[0252] The method of the above-mentioned embodiment 1 is referred to, except that the doping material RD002 is replaced by PRD-07, and the main material RH-1 is replaced by RH-120.

[0253] Comparative Example 1

[0254] An organic electroluminescent device was prepared in the same manner as in Example 1, except that PRH-01 was used instead of the host compound RH-1 in Example 1.

[0255] Comparative Example 2

[0256] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by PRD-09.

[0257] Comparative Example 3

[0258] An organic electroluminescent device was prepared in the same manner as in Example 1, except that PRD-10 was used instead of the doping compound RD002 in Example 1, and PRH-01 was used instead of the main compound RH-1 in Example 1.

[0259] Comparative Example 4

[0260] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-01.

[0261] Comparative Example 5

[0262] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by mCP.

[0263] Comparative Example 6

[0264] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-02.

[0265] Comparative Example 7

[0266] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-03.

[0267] Comparative Example 8

[0268] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-04.

[0269] Comparative Example 9

[0270] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-05.

[0271] Comparative Example 10

[0272] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-06.

[0273] Comparative Example 11

[0274] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-07.

[0275] Comparative Example 12

[0276] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the doping compound RD002 in Example 1 was replaced by the compound of the following formula PRD-08.

[0277] Comparative Example 13

[0278] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-02.

[0279] Comparative Example 14

[0280] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by a compound of the following formula PRH-03.

[0281] Comparative Example 15

[0282] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-04.

[0283] Comparative Example 16

[0284] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-05.

[0285] Comparative Example 17

[0286] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by a compound of the following formula PRH-06.

[0287] Comparative Example 18

[0288] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-07.

[0289] Comparative Example 19

[0290] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-08.

[0291] Comparative Example 20

[0292] An organic electroluminescent device was prepared in the same manner as in Example 1, except that the host compound RH-1 in Example 1 was replaced by the compound of the following formula PRH-09.

[0293] The structures used in the above comparative examples 1-20 are as follows:

[0294]

[0295] The driving voltage, luminous efficiency and life of the organic electroluminescent devices obtained from the above device embodiments 1-30 and device comparative examples 1-20 were characterized at a brightness of 2000 (nits). The test results are shown in the following table:

[0296]

[0297]

[0298]

[0299] As can be seen from Table 1, the organic electroluminescent device prepared by using the compound provided by the present invention as both the doping material and the main material of the light-emitting layer has a significantly lower driving voltage, and the luminous efficiency, power efficiency and life are significantly improved compared with the organic electroluminescent device prepared by using the doping material or the main material alone and the organic electroluminescent device prepared in the comparative example.

[0300] The above embodiments only list the effect data of devices made of a part of the structural formulas. This is a representative sampling test. According to the experimental data, the overall data is not much different and can represent the effects of other unlisted structures.

[0301] It will be apparent to those skilled in the art that many modifications and variations of the present invention are possible without departing from the spirit and scope of the present invention. It is therefore contemplated that the present invention covers modifications and variations of the present invention provided within the scope of the appended claims and their equivalents.

[0302] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent device, characterized in that: The invention comprises a substrate, a first electrode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic electroluminescent layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode which are arranged in sequence; The organic electroluminescent layer includes a main material and a luminescent material, and the doping material in the luminescent material has a compound having a structure shown in the following formula RD: in, A is selected from one of the following structures A-1 to A-22: in, q is an integer between 1 and 10; * is the connection key; X is selected from one of C and Si; Y is selected from one of O and S; R1 and R2 are each independently selected from one of D, -CH3, -CD3, and -CH2CH3; R4-R7 and Ar1 are each independently selected from any one of -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, substituted or unsubstituted C2-C6 alkyl, substituted or unsubstituted C6-C10 aryl and substituted or unsubstituted 4-8 membered aromatic heterocyclic group, and two adjacent substituents of R4-R7 form a C4-C12 aromatic ring or aromatic heterocyclic ring.

2. The organic electroluminescent device according to claim 1, characterized in that: The alkyl groups in R4-R7 and Ar1 are each independently selected from any one of substituted or unsubstituted straight-chain alkyl groups, substituted or unsubstituted branched-chain alkyl groups and substituted or unsubstituted cycloalkyl groups.

3. The organic electroluminescent device according to claim 1, characterized in that: The heteroatoms in the heteroaryl groups in R4-R7 and Ar1 are each independently selected from at least one of N, S and O.

4. The organic electroluminescent device according to claim 1, characterized in that: Two adjacent substituents of R4-R7 form a benzene ring.

5. The organic electroluminescent device according to claim 1, characterized in that: The doping material is selected from one of the following structures:

6. The organic electroluminescent device according to claim 1, characterized in that: The main material has a compound having a structure shown in the following formula RH: in, The L is selected from a connecting bond, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 6-30 membered aromatic heterocyclic group; The Ar2 has the following structure: in, Said is the connection location; The R7 and R8 are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 6-30 membered aromatic heterocyclic group, substituted or unsubstituted C10-C30 fused ring group, substituted or unsubstituted C5-C30 spiro ring.

7. The organic electroluminescent device according to claim 6, characterized in that: The main material is selected from one of the following structural compounds:

8. The organic electroluminescent device according to claim 1, characterized in that: The organic electroluminescent layer includes multiple monochromatic light-emitting layers, and the multiple monochromatic light-emitting layers emit one of the single colors of red, green, and blue. The multiple monochromatic light-emitting layers can be arranged in a planar manner according to a pixel pattern, or can be stacked together to form a color light-emitting layer. When monochromatic light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other.

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