Organic luminescent material, application thereof and organic electroluminescent device

Abstract

The invention discloses an organic light-emitting material, application thereof and an organic electroluminescent device, and belongs to the technical field of organic light-emitting materials. The organic light-emitting material has a structure as shown in the following general formula (I): # imgabs0 #, wherein R1 and R2 are respectively selected from one of C6-C18 aryl, C6-C18 heteroaryl and a combination of the C6-C18 aryl, the C6-C18 heteroaryl and the combination of the C6-C18 heteroaryl and the C6-C18 heteroaryl. An organic matter layer in the organic light-emitting device comprises an electron transport layer and / or a hole blocking layer, and the electron transport layer and / or the hole blocking layer comprise the organic light-emitting material. According to the organic light-emitting material provided by the invention, by selecting specific aromatic hydrocarbon, heterocyclic aromatic hydrocarbon and a combination thereof, after the obtained organic light-emitting material is applied to a hole transport layer of an organic light-emitting device, the light-emitting efficiency of the device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of organic light-emitting materials, and in particular to an organic light-emitting material, application thereof and an organic electroluminescent device. Background Art

[0002] Organic electroluminescent devices (OLEDs) are devices that use organic materials to directly convert electrical energy into light energy. Organic electroluminescent devices are not only thin and light, have a wide viewing angle, fast response, a wide operating temperature range, low energy consumption, and high efficiency, but also have good color purity and high clarity, and can achieve flexible display. They have been widely used in electronic products such as mobile phones, computers, televisions, and wearable devices.

[0003] Organic electroluminescent devices generally consist of two opposing electrodes and at least one layer of organic light-emitting compound inserted between the two electrodes. Charges are injected into the organic layer formed between the anode and the cathode to form electron and hole pairs, causing the organic compound with fluorescent or phosphorescent properties to produce light emission.

[0004] With the development of organic electroluminescent devices, the luminous efficiency and service life of organic electroluminescent devices have become important issues that need to be solved at present. However, in order to further improve the luminous efficiency of organic electroluminescent devices and extend the service life of organic electroluminescent devices, it is necessary to obtain materials with balanced hole and electron transport, and control the holes and electrons in the light-emitting layer to effectively recombine them. The key lies in the mutual matching between the energy levels of each functional layer and the properties of the material itself. Only when the best combination is achieved between each organic layer can the performance of the organic electroluminescent device be truly improved. Therefore, it is necessary to develop hole transport region materials and electron transport region materials with good thermal stability and film forming properties, energy level matching and device charge balance, so as to improve the luminous efficiency of organic electroluminescent devices and extend the service life of organic electroluminescent devices. Summary of the invention

[0005] In view of the shortcomings of the prior art, an object of the present invention is to provide an organic light-emitting material, its application and an organic electroluminescent device.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] An organic light-emitting material having a structure shown in the following general formula (I):

[0008]

[0009] Where: R 1 and R 2 Selected from C 6 -C 18 Aryl, C6 -C 18 One of heteroaryl and combinations thereof.

[0010] The aromatic group is one of benzene, biphenyl, terphenyl, naphthalene and fluorene.

[0011] The heteroaryl group is one of dibenzothiophene and dibenzofuran.

[0012] The organic light-emitting material is selected from any one of the following structures:

[0013]

[0014]

[0015]

[0016]

[0017] An application of the organic light-emitting material in an organic electroluminescent device.

[0018] An organic electroluminescent device comprises a first electrode, a second electrode and at least one organic layer arranged between the first electrode and the second electrode, wherein the organic layer comprises the organic luminescent material.

[0019] An organic electroluminescent device, wherein the organic layer comprises an electron transport layer and / or a hole blocking layer, and the electron transport layer and / or the hole blocking layer contain the organic light-emitting material.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention include:

[0021] The organic light-emitting material provided by the present invention is obtained by selecting specific aromatic hydrocarbons, heterocyclic aromatic hydrocarbons and combinations thereof. After being used in the hole transport layer of an organic electroluminescent device, the light-emitting efficiency and service life of the device are improved. DETAILED DESCRIPTION

[0022] The invention will be further described below in conjunction with the embodiments, but the invention is not limited to these embodiments.

[0023] Example 1

[0024] An organic light-emitting material HT-08, i.e. a compound numbered HT-08, has the following specific synthesis steps:

[0025] (1) Preparation of compound HT-08-1

[0026]

[0027] Under nitrogen protection, compound naphtho[1,2-b]furan (CAS: 234-03-7) (500mmol), NBS (505mmol), and dichloromethane (300ml) were added to a 500ml three-necked reaction bottle in sequence and reacted at 0-5°C for 12 hours. After the reaction was completed by TLC monitoring, the reaction solution was filtered, the filtrate was concentrated to dryness and recrystallized with anhydrous ethanol (180ml), and the filter cake was vacuum dried to obtain compound HT-08-1 (97.57g, yield 79%). The test results of compound HT-08-1 are as follows:

[0028] HPLC purity: 99.4%;

[0029] Mass spectrum: calculated value is 245.97, tested value is 245.99;

[0030] Elemental analysis calculated values: C: 58.33%, H: 2.86%, Br: 32.33%, O: 6.48%;

[0031] Element analysis test values: C: 58.23%, H: 2.96%, Br: 32.32%, O: 6.49%.

[0032] (2) Preparation of compound HT-08-2

[0033]

[0034] Under nitrogen protection, compound HT-08-1 (300mmol), phenylboric acid (310mmol), tetrakistriphenylphosphine palladium (0.2mmol), potassium carbonate (600mmol), toluene (400ml), ethanol (250ml) and water (300ml) were added to a 1000ml three-necked reaction bottle in sequence, and the reaction was refluxed for 12 hours. After the reaction was completed by TLC monitoring, the reaction solution was cooled to room temperature, washed with water until neutral, dried with magnesium sulfate, the filtrate was concentrated to dryness and recrystallized with anhydrous ethanol (200ml), and the filter cake was vacuum dried to obtain compound HT-08-2 (59.36g, yield 81%). The test results of compound HT-08-2 are as follows:

[0035] HPLC purity: 99.2%;

[0036] Mass spectrum: calculated value is 244.09, measured value is 244.05;

[0037] Elemental analysis calculated values: C: 88.50%, H: 4.95%, O: 6.55%;

[0038] Element analysis test values: C: 88.49%, H: 4.95%, O: 6.56%.

[0039] 3) Preparation of compound HT-08-3

[0040]

[0041] Under nitrogen protection, compound HT-08-2 (250mmol) and THF (200ml) were added to a 1000ml three-necked reaction bottle in sequence, the reaction system was cooled to -50°C, kept below -50°C, n-butyl lithium (300mmol) was slowly added dropwise, and after the addition was completed, the reaction was kept warm for 2h, 50ml of dilute hydrochloric acid (concentration 3mol / L) was added dropwise to the system, the product precipitated, the product was washed with water until neutral, and the filter cake was vacuum dried to obtain compound HT-08-3 (59.30g, yield 78%). The test results of compound HT-08-3 are as follows:

[0042] HPLC purity: 99.6%;

[0043] Mass spectrum: calculated value is 304.13, measured value is 304.09;

[0044] Elemental analysis calculated values: C: 75.03%, H: 5.63%, B: 3.55, O: 15.79%;

[0045] Element analysis test values: C: 75.01%, H: 5.65%, B: 3.52, O: 15.82%.

[0046] (4) Preparation of Compound HT-08-4

[0047]

[0048] Under nitrogen protection, compound HT-08-3 (200mmol), 4-bromodeuterated chlorobenzene (260mmol), tetrakistriphenylphosphine palladium (0.2mmol), potassium carbonate (300mmol), toluene (500ml), ethanol (300ml) and water (300ml) were added to a 2000ml three-necked reaction bottle in sequence, and the reaction was refluxed for 12 hours. After the reaction was completed by TLC monitoring, the reaction solution was cooled to room temperature, washed with water until neutral, dried with magnesium sulfate, the filtrate was concentrated to dryness and recrystallized with anhydrous ethanol (250g), and the filter cake was vacuum dried to obtain compound HT-08-4 (50.24g, yield 70%). The test results of compound HT-08-4 are as follows:

[0049] HPLC purity: 99.5%;

[0050] Mass spectrum: calculated value is 358.11, measured value is 358.09;

[0051] Elemental analysis calculated values: C: 80.33%, H: 5.33%, CL: 9.88%, O: 4.46%;

[0052] Element analysis test values: C: 80.31%, H: 5.35%, CL: 9.89%, O: 4.45%.

[0053] (5) Preparation of Compound HT-08

[0054]

[0055] Under nitrogen protection, compound HT-08-4 (100mmol), N-biphenyl-3-benzidine (102mmol), palladium acetate (0.2mmol), sodium tert-butoxide (50mmol), tri-tert-butylphosphine (0.2mmol) and toluene (300ml) were added to a 1000ml three-necked reaction bottle in sequence, and refluxed for 24 hours, and solid precipitation was precipitated. After the reaction was completed by TLC monitoring, the reaction solution was cooled to room temperature and filtered under negative pressure. The precipitated solid product was washed with 20ml pure water, 20ml methanol, and 20ml petroleum ether in sequence, and the filter cake was vacuum dried to obtain compound HT-08 (45.06g, yield 70%). The test results of compound HT-08 are as follows:

[0056] HPLC purity: 99.8%;

[0057] Mass spectrum: calculated value is 643.28, tested value is 643.21;

[0058] Elemental analysis calculated values: C: 89.55%, H: 5.79%, N: 2.18%, O: 2.49%;

[0059] Element analysis test values: C: 91.10%, H: 5.08%, N: 1.80%, O: 2.10%.

[0060] Example 2

[0061] An organic light-emitting material HT-13, i.e. a compound numbered HT-13, has the following specific synthesis steps:

[0062]

[0063] Under nitrogen protection, compound HT-08-4 (100mmol), N-phenyl-dibenzofuran-2-amine (102mmol), palladium acetate (0.2mmol), sodium tert-butoxide (50mmol), tri-tert-butylphosphine (0.2mmol) and toluene (300ml) were added to a 1000ml three-necked reaction bottle in sequence, and refluxed for 24 hours, and solid precipitation was precipitated. After the reaction was completed by TLC monitoring, the reaction solution was cooled to room temperature and filtered under negative pressure. The precipitated solid product was washed with 20ml pure water, 20ml methanol, and 20ml petroleum ether in sequence, and the filter cake was vacuum dried to obtain compound HT-13 (40.65g, yield 68%). The test results of compound HT-13 are as follows:

[0064] HPLC purity: 99.7%;

[0065] Mass spectrum: calculated value is 597.26, measured value is 597.21;

[0066] Elemental analysis calculated values: C: 86.40%, H: 5.90%, N: 2.34%, O: 5.36%;

[0067] Element analysis test values: C: 86.39%, H: 5.91%, N: 2.32%, O: 5.38%.

[0068] Example 3

[0069] An organic light-emitting material HT-33, i.e. a compound numbered HT-33, has the following specific synthesis steps:

[0070]

[0071] Under nitrogen protection, compound HT-08-4 (100 mmol), N-(dibenzo[b, d]thiophene-3-yl)-dibenzo[b, d]furan-2-amine (HT-000, 102 mmol), palladium acetate (0.2 mmol), sodium tert-butoxide (50 mmol), tri-tert-butylphosphine (0.2 mmol) and toluene (300 ml) were added into a 1000 ml three-necked reaction bottle in sequence, and the reaction was refluxed for 24 hours, and solid precipitation was precipitated. After the reaction was completed by TLC monitoring, the reaction solution was cooled to room temperature and filtered under negative pressure. The precipitated solid product was washed with 20 ml of pure water, 20 ml of methanol, and 20 ml of petroleum ether in sequence, and the filter cake was vacuum dried to obtain compound HT-33 (45.75 g, yield 65%). The test results of compound HT-33 are as follows:

[0072] HPLC purity: 99.7%;

[0073] Mass spectrum: calculated value is 703.25, tested value is 703.21;

[0074] Elemental analysis calculated values: C: 83.60%, H: 5.30%, N: 1.99%, O: 4.55%, S: 4.56%;

[0075] Element analysis test values: C: 83.59%, H: 5.31%, N: 1.97%, O: 4.56%, S: 4.57%.

[0076] HT-08-4 is recorded as substrate A, and the compound of another reaction is recorded as substrate B. The synthesis methods of other numbered luminescent materials are the same as above, and all use substrate A and substrate B to react, which will not be repeated here. The mass spectra and molecular formulas of other synthetic examples are shown in the following table:

[0077] Table 1 Statistics of calculated and tested mass spectrometry values ​​of luminescent materials

[0078] Luminescent Materials Molecular formula Mass spectrometry calculated value Mass spectrometry test value HT-01 <![CDATA[C 36 H 21 D 4 NO]]> 491.22 491.19 HT-06 <![CDATA[C 48 H 29 D 4 NO]]> 643.28 643.29 HT-11 <![CDATA[C 60 H 37 D 4 NO]]> 795.34 795.31 HT-15 <![CDATA[C 48 H 27 D 4 NO 2 ]]> 657.26 567.22 HT-19 <![CDATA[C 51 H 33 D 4 NO]]> 683.31 683.30 HT-23 <![CDATA[C 48 H 27 D 4 NOS]]> 673.24 673.25 HT-28 <![CDATA[C 51 H 31 D 4 NO 2 ]]> 697.29 697.27 HT-32 <![CDATA[C 51 H 31 D 4 NOS]]> 713.27 713.29 HT-35 <![CDATA[C 48 H 25 D 4 NO 2 S]]> 687.22 687.20 HT-38 <![CDATA[C 54 H 31 D 4 NO 2 ]]> 733.29 733.24 HT-43 <![CDATA[C 54 H 31 D 4 NOS]]> 749.27 749.28 HT-46 <![CDATA[C 57 H 37 D 4 NO]]> 759.34 759.31

[0079] The present invention also provides an organic electroluminescent device, which is made of the organic light-emitting material, and more specifically, made of the organic light-emitting material shown in Formula 1.

[0080] Example 4

[0081] An organic electroluminescent device was prepared using the luminescent material HT-08 prepared in Example 1, and the preparation steps were as follows:

[0082] The coating thickness is The ITO glass substrate was washed twice in distilled water, ultrasonically washed for 30 minutes, and repeatedly washed twice with distilled water (100 ml each time), ultrasonically washed for 10 minutes. After the distilled water washing, it was ultrasonically washed in sequence with 100 ml isopropanol, 100 ml acetone, and 100 ml methanol solvents, dried, and transferred to a plasma cleaning machine. The above substrate was washed for 5 minutes and sent to a vapor deposition machine. First, the hole transport layer HT-08 was vapor-deposited on the ITO (anode). The main material luminescent material GH-01 and the dopant material luminescent material GD-01 are mixed in a weight ratio of 95:5 and then evaporated. Evaporated electron transport layer ET-01 Evaporated electron injection layer LiF Evaporated cathode Al The organic electroluminescent device was prepared in the form of a KEITHLEY 2400 source measurement unit and a CS-2000 spectroradiometer were used to test the performance of the device and evaluate the driving voltage, luminous brightness and luminous efficiency.

[0083] Referring to the above method, the luminescent material HT-08 was replaced with HT-01, HT-02, HT-12, HT-16, HT-20, HT-24, HT-28, HT-36, HT-48 and the materials of comparative example 1 to prepare organic electroluminescent devices containing corresponding luminescent materials.

[0084] The codes ET-01, GH-01, and GD-01 represent compounds of the following structures respectively, and the material of Comparative Example 1 has the following structural formula.

[0085]

[0086] The prepared organic electroluminescent device was subjected to the same data detection as in Example 4. The results are shown in Table 2.

[0087] Table 2 Test results of organic electroluminescent devices

[0088]

[0089]

[0090] It can be seen from Table 2 that the organic electroluminescent device prepared by using the organic light-emitting material provided by the present invention as the hole transport layer material has a significantly lower driving voltage, and a significantly improved current efficiency and lifespan, compared with the organic electroluminescent device prepared by using the comparative material Example 1 as the hole transport layer material.

[0091] The organic light-emitting material provided by the present invention is obtained by selecting specific aromatic hydrocarbons, heterocyclic aromatic hydrocarbons and combinations thereof. After being used in an organic electroluminescent device, the light-emitting efficiency of the device is improved, the service life is increased, and the driving voltage is reduced.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in the field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. An organic light-emitting material, characterized in that: It has the structure shown in the following general formula (I): Wherein: R1 and R2 are selected from C6-C 18 Aryl, C6-C 18 One of heteroaryl and combinations thereof.

2. An organic light-emitting material according to claim 1, characterized in that: The aromatic group is one of benzene, biphenyl, terphenyl, naphthalene and fluorene.

3. The organic light-emitting material according to claim 1, characterized in that: The heteroaryl group is one of dibenzothiophene and dibenzofuran.

4. The organic light-emitting material according to claim 1, characterized in that: The organic light-emitting material is selected from any one of the following structures:

5. Use of the organic light-emitting material according to any one of claims 1 to 4 in an organic electroluminescent device.

6. An organic electroluminescent device, comprising a first electrode, a second electrode and at least one organic layer disposed between the first electrode and the second electrode, characterized in that: The organic layer comprises the organic light-emitting material according to any one of claims 1 to 4.

7. An organic electroluminescent device according to claim 6, characterized in that: The organic layer includes an electron transport layer and / or a hole blocking layer, and the electron transport layer and / or the hole blocking layer contain the organic light-emitting material.

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