CN111303187B - Organic luminescent material and organic electroluminescent device - Google Patents

Abstract

The application provides a novel organic luminescent material, which has a structure shown in a general formula (I) and can be used for organic electroluminescent devices and electron transport layer materials. The present application also provides an organic electroluminescent device comprising the novel organic luminescent material of the present application. The organic luminescent material disclosed by the application has a parent structure of indolocarbazole, has high bond energy among atoms, has good thermal stability, is favorable for solid accumulation among molecules, and can effectively prolong the service life of the material when being used as a luminescent layer material. Meanwhile, the preparation process of the derivative is simple and feasible, raw materials are easy to obtain, and the derivative is suitable for industrial production.

Description

Organic light-emitting material and organic electroluminescent device

Technical Field

The present application relates to a novel organic compound, in particular to an organic light-emitting material and an organic electroluminescent device using the organic light-emitting material.

Background Art

Electroluminescence (EL) refers to the phenomenon that luminescent materials emit light under the action of electric field and are stimulated by electric current and electric field. It is a luminescence process that directly converts electrical energy into light energy. Organic electroluminescent displays (hereinafter referred to as OLEDs) have a series of advantages such as autonomous luminescence, low-voltage DC drive, full curing, wide viewing angle, light weight, simple composition and process. Compared with liquid crystal displays, organic electroluminescent displays do not require backlight sources, have large viewing angles, low power consumption, and their response speed can reach 1000 times that of liquid crystal displays, but their manufacturing cost is lower than that of liquid crystal displays with the same resolution. Therefore, organic electroluminescent devices have a very broad application prospect.

With the continuous advancement of OLED technology in the two major fields of lighting and display, people are paying more attention to the research on high-efficiency organic materials that affect the performance of OLED devices. An organic electroluminescent device with high efficiency and long life is usually the result of an optimized combination of device structure and various organic materials. This provides great opportunities and challenges for chemists to design and develop functional materials of various structures.

Compared with inorganic light-emitting materials, organic electroluminescent materials have many advantages, such as good processing performance, can be formed on any substrate by evaporation or spin coating, can achieve flexible display and large-area display; can adjust the optical properties, electrical properties and stability of the material by changing the molecular structure, and there is a lot of room for material selection. In the most common OLED device structure, the following types of organic materials are usually included: hole injection materials, hole transport materials, electron transport materials, and various luminescent materials (dyes or doped guest materials) and corresponding host materials. The currently used phosphorescent host materials often have a single carrier transport capability, such as hole transport hosts and electron transport hosts. However, the single carrier transport capability will cause mismatch between electrons and holes in the light-emitting layer, resulting in serious efficiency roll-off and shortened life.

CN109824672A discloses a quinazoline triazole structure as an electron transport material, and the electron mobility of this type of material has room for improvement.

Summary of the invention

To this end, the object of the present application is to provide an organic light-emitting material and an organic electroluminescent device using the organic light-emitting material.

The first aspect of the present application provides an organic light-emitting material, characterized in that it has a structure shown in the following general formula (I):

L-Ar ²

(II)

in,

Ar ¹ is selected from C ₆ -C ₃₀ aromatic groups which are unsubstituted or substituted by Ra, and C ₃ -C ₃₀ heteroaryl groups which are unsubstituted or substituted by Ra;

R ¹ -R ⁴ are the same as or different from each other and are independently selected from hydrogen, deuterium, C ₁ -C ₁₀ alkyl, C ₆ -C ₃₀ aryl unsubstituted or substituted by Ra, C ₃ -C ₃₀ heteroaryl unsubstituted or substituted by Ra, and at least one of R ¹ is connected to the compound of formula (II), wherein adjacent R ¹ -R ⁴ can be connected to form a ring;

L is selected from a chemical bond, a C ₆ -C ₃₀ arylene group or a C ₃ -C ₃₀ heteroarylene group;

Ar ² is selected from C5-C20 nitrogen-containing heteroaryl groups;

X is selected from O, S, CR ⁵ R ⁶ , NR ⁷ ; R ⁵ and R ⁶ are independently selected from C ₁ -C ₁₀ alkyl, C ₁ -C ₆ cycloalkyl, C _{6 -C 30 aryl unsubstituted or substituted by Ra, C 3 -C 30 heteroaryl unsubstituted or substituted by Ra; R 7 is selected from C 6 -C 30 aryl} ^{unsubstituted} _{or substituted} by Ra, C ₃ -C ₃₀ heteroaryl unsubstituted or substituted by Ra;

The substituents Ra of the individual groups may be identical or different and are independently selected from hydrogen, halogen, nitro, cyano, C ₁ -C ₄ alkyl, phenyl, biphenyl, terphenyl or naphthyl.

Preferably, Ar ¹ is selected from the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, fluorenyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, cinnolinyl, naphthyridinyl, triazine, pyridopyrazinyl, furanyl, benzofuranyl, dibenzofuranyl, aza-dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, aza-dibenzothienyl, 9,9-dimethylfluorenyl, spirofluorenyl, arylamine, carbazolyl.

Preferably, R ¹ -R ⁴ are independently selected from hydrogen, deuterium, methyl, ethyl, the following groups which are unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, fluorenyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, cinnolinyl, naphthyridinyl, triazine, pyridopyrazinyl, furanyl, benzofuranyl, dibenzofuranyl, aza-dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, aza-dibenzothienyl, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amine, carbazole group.

Preferably, R ⁵ and R ⁶ are independently selected from methyl, ethyl, cyclopentyl, cyclohexyl, the following groups which are unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl, triphenylene, fluorenyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, cinnolinyl, naphthyridinyl, triazine, pyridopyrazinyl, furanyl, benzofuranyl, dibenzofuranyl, aza-dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, aza-dibenzothienyl, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amine, carbazole group.

Preferably, R ⁷ is selected from the following groups which are unsubstituted or substituted with Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl, triphenylene, fluorenyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, cinnolinyl, naphthyridinyl, triazine, pyridopyrazinyl, furanyl, benzofuranyl, dibenzofuranyl, aza-dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, aza-dibenzothienyl, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amine, carbazole group.

Preferably, Ar ² is independently selected from pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, cinnolinyl, naphthyridinyl, triazinyl, pyridopyrazinyl.

Preferably, L is selected from a chemical bond, or a subunit of the following compounds which are unsubstituted or substituted with Ra: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, 9,9-dimethylfluorene, spirofluorene, aromatic amine, carbazole.

More preferably, the organic light-emitting material is selected from the following compounds A1-A36:

The second aspect of the present application also provides an organic electroluminescent device, which comprises the organic light-emitting material of the present application.

The organic light-emitting material of the present application can be used as an electron transport material in an organic electroluminescent device.

The organic light-emitting material disclosed in the present application has a parent structure of indolecarbazole, high bond energy between atoms, good thermal stability, and is conducive to solid-state accumulation between molecules. Use as a light-emitting layer material can effectively increase the life of the material.

The aromatic amine-substituted indole heterocyclic derivatives described in the present application are used in the light-emitting layer, and have a suitable energy level between adjacent layers, which is conducive to the injection of holes and electrons, and can effectively reduce the turn-on voltage. At the same time, the high exciton migration rate can achieve good luminous efficiency in the device. The compounds of the present application have a large conjugated plane, which is conducive to molecular stacking, and show good thermodynamic stability, which is manifested as a long life in the device.

At the same time, the preparation process of the derivatives described in the present application is simple and easy, the raw materials are easily available, and it is suitable for industrial production.

DETAILED DESCRIPTION

The organic light-emitting material of the present application can be used as an electron transport material in an organic electroluminescent device.

In the present application, there is no particular restriction on the type and structure of the organic electroluminescent device, as long as the organic light-emitting material provided in the present application can be used. For the sake of convenience, the present application takes the organic light-emitting diode as an example for illustration, but this does not mean any limitation on the protection scope of the present application. It is understood that all organic electroluminescent devices that can use the organic light-emitting material of the present application are within the protection scope of the present application.

Generally, an organic light emitting diode includes a first electrode and a second electrode on a substrate, and an organic material layer between the electrodes, wherein the organic material layer may be a multilayer structure. For example, the organic material layer may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like.

In the present application, the substrate is not particularly limited, and conventional substrates used in organic electroluminescent devices in the prior art may be used, such as glass, polymer materials, and glass and polymer materials with TFT components.

In the present application, the anode material is not particularly limited and can be transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide ( _SnO2 ), zinc oxide (ZnO) known in the prior art, or metal materials such as silver and its alloys, aluminum and its alloys, or organic conductive materials such as PEDOT, as well as multilayer structures of the above materials, etc.

In the present application, the cathode material is not particularly limited, for example, it can be selected from but not limited to magnesium-silver mixture, LiF/Al, ITO and other metals, metal mixtures, oxides and other materials.

In the present application, the organic light-emitting diode (OLED) may also include a hole injection layer, a hole transport layer, etc. located between the light-emitting layer and the anode. These layers may use but are not limited to at least one of the HT1-HT31 listed below. These materials may be used alone or in combination of multiple types.

In the present application, the light-emitting layer of the device may include a host material and a light-emitting dye, wherein the host material includes but is not limited to a combination of one or more conventional materials shown in the following GPH1-GPH80.

In a preferred embodiment of the present application, the light-emitting layer adopts phosphorescent electroluminescence technology. The light-emitting layer is doped with a phosphorescent dopant, and the phosphorescent dopant can be selected from but not limited to one or more combinations of RPD-1 to RPD-28 listed below.

The electron transport material includes, but is not limited to, one or more combinations of the following ET1-ET57 materials. The electron transport material of the present application can be used in combination with one or more of these materials.

In addition, the OLED device may further include an electron injection layer located between the electron transport layer and the cathode. The material of the electron injection layer is not particularly limited. For example, it may include but is not limited to one or a combination of materials such as LiQ, LiF, NaCl, CsF, Li ₂ O, Cs ₂ CO ₃ , BaO, Na, Li, Ca, etc. in the prior art.

In the present application, the following materials are used to conduct comparative experiments with the organic light-emitting materials of the present application.

The synthesis method of the compound of the present application is not particularly limited, and any method known to those skilled in the art can be used for synthesis. The following examples illustrate the synthesis process of the compound of the present application.

Synthesis Example

Synthesis Example 1: Synthesis of Compound A2

100 mmol of 5-chlorobenzoxazole was dissolved in 300 ml of dichloromethane, and 100 mmol of bromine was added dropwise at 0°C. The reaction was allowed to proceed for 3 h. After the reaction was completed, water was added, and the organic phase was washed with water and concentrated to obtain intermediate M1.

Add M1 (1000mmol, 1.0eq) and dichloromethane (2000ml) to a 10L three-necked flask, and stir to dissolve. Control the temperature below 10°C, pour in 416mL of triethylamine (3000mmol, 3.0eq), control the temperature below 10°C, drop 93.75g of hydrazine hydrate (1500mmol, 1.5eq), then naturally warm to room temperature, react for 1 hour, and monitor the completion of the reaction by thin layer chromatography (TLC). Add 4000ml of pure water, stir for 30 minutes, and filter; add the obtained solid to a 4000ml beaker containing 2000ml of pure water, stir for 10 minutes, filter, and dry to obtain a white solid M2.

Benzaldehyde (175.8mmol, 1.1eq), intermediate M2 (159.8mmol, 1.0eq) and 1000ml ethanol were added to a single-mouth bottle, stirred until the solution was clear and then continued to stir for 30 minutes, and the raw material disappeared after TLC monitoring. 57g (175.8mmol, 1.1eq) iodophenyl diacetic acid was added in batches, and then stirred for 1 hour, and solids gradually precipitated. After the reaction was completed after TLC monitoring, it was filtered, and the filter cake was rinsed with ethanol until the filtrate was a colorless clear liquid to obtain a brown solid M3.

Add 100 mmol of M3, 100 mmol of M4, 40 g of potassium carbonate (300 mmol), 800 ml of DMF and 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh ₃ ) ₄ . React at 120°C for 12 hours. After the reaction is completed, stop the reaction, and cool the reactant to room temperature, add water, filter, and wash with water. The obtained solid is recrystallized and purified with toluene to obtain white powder A2. The amount of Pd(PPh ₃ ) ₄ added is 1 mol% of M3 and M4.

¹ H NMR (400MHz, Chloroform) δ8.50–8.34(m,6H),8.28(s,1H),7.79(d,J＝12.0Hz,4H),7.70(s,1H),7.59(d,J ＝13.2Hz,4H),7.50(m,6H).

Synthesis Example 2: Synthesis of Compound A5

100 mmol of 5-chlorobenzoxazole was dissolved in 300 ml of dichloromethane, and 100 mmol of bromine was added dropwise at 0°C. The reaction was allowed to proceed for 3 h. After the reaction was completed, water was added, and the organic phase was washed with water and concentrated to obtain intermediate M1.

Add M1 (1000mmol, 1.0eq) and dichloromethane (2000ml) to a 10L three-necked flask, and stir to dissolve. Control the temperature below 10°C, pour in 416mL of triethylamine (3000mmol, 3.0eq), control the temperature below 10°C, and drop 93.75g of hydrazine hydrate (1500mmol, 1.5eq). After the addition is complete, naturally warm to room temperature and react for 1 hour. The reaction is complete after TLC monitoring. Add 4000ml of pure water, stir for 30 minutes, and filter; add the obtained solid to a 4000ml beaker containing 2000ml of pure water, stir for 10 minutes, filter, and dry to obtain a white solid M2.

Add benzaldehyde (175.8mmol, 1.1eq), M2 (159.8mmol, 1.0eq) and 1000ml ethanol to a single-mouth bottle, stir until the solution is clear and continue stirring for 30 minutes. TLC monitoring shows that the raw material disappears. Add 57g (175.8mmol, 1.1eq) iodophenyl diacetic acid in batches. Stir for 1 hour after addition. Solids gradually precipitate. After TLC monitoring, filter and rinse the filter cake with ethanol until the filtrate is a colorless clear liquid to obtain brown solid M3.

Add 100mmol intermediate M3, 120mmol biboric acid pinacol ester, 300mmol potassium acetate, 800ml DMF into the reaction flask, then add 1mol% Pd(dppf)Cl ₂ , and react at 120°C for 12h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and purify the obtained solid by recrystallization with toluene to obtain white powder M4. The amount of Pd(dppf)Cl ₂ added is 1mol% of M3.

100 mmol of M4, 100 mmol of 2-chloro-4-phenylquinazoline, 40 g of potassium carbonate (300 mmol), 800 ml of DMF and 200 ml of water were added to a reaction flask, and then 1% of Pd(PPh ₃ ) ₄ was added, and the reaction was carried out at 120° C. for 12 hours. After the reaction was completed, the reaction was stopped, and the reactant was cooled to room temperature, added with water, filtered, washed with water, and the obtained solid was recrystallized and purified with toluene to obtain white powder A5. The amount of Pd(PPh ₃ ) ₄ added was 1 mol% of M4.

¹ H NMR (CDCl3, 400MHz) δ8.35 (s, 1H), 8.28 (s, 1H), 8.11 (d, J = 10.0Hz, 2H), 7.78 (d, J = 8.4Hz, 2H), 7.57 ( dd,J＝10.0,8.4Hz,4H),7.49(m,6H).

Synthesis Example 3: Synthesis of Compound A16

Add 2-bromo-5-chloro-3,3-dimethylindole (1000mmol, 1.0eq) and dichloromethane (2000ml) to a 10L three-necked flask and stir to dissolve. Control the temperature below 10°C, pour in 416mL of triethylamine (3000mmol, 3.0eq), control the temperature below 10°C, drop 93.75g of hydrazine hydrate (1500mmol, 1.5eq), add the solution after the addition, naturally warm to room temperature, react for 1 hour, and monitor the reaction by TLC. Add 4000ml of pure water, stir for 30 minutes, and filter; add the obtained solid to a 4000ml beaker containing 2000ml of pure water, stir for 10 minutes, filter, and dry to obtain a white solid M1.

Add benzaldehyde (175.8mmol, 1.1eq), M1 (159.8mmol, 1.0eq) and 1000ml ethanol to a single-mouth bottle, stir until the solution is clear and continue stirring for 30 minutes. TLC monitoring shows that the raw material disappears. Add 57g (175.8mmol, 1.1eq) iodophenyl diacetic acid in batches. Stir for 1 hour after addition. Solids gradually precipitate. After TLC monitoring shows that the reaction is complete, filter and rinse the filter cake with ethanol until the filtrate is a colorless clear liquid to obtain brown solid M2.

100 mmol of M2, 100 mmol of M3, 40 g (300 mmol) of potassium carbonate, 800 ml of DMF, 200 ml of water were added to a reaction flask, and then 1 mol% of Pd(PPh ₃ ) ₄ was added, and the reaction was carried out at 120°C for 12 hours. After the reaction was completed, the reaction was stopped, and the reactant was cooled to room temperature, added with water, filtered, washed with water, and the obtained solid was recrystallized and purified with toluene to obtain white powder A16. The amount of Pd(PPh ₃ ) ₄ added was 1 mol% of M2.

¹ H NMR (CDCl3, 400MHz) δ8.36 (m, 4H), 8.28 (s, 2H),, 7.50 (m, 10H), 7.24 (s, 2H), 1.74 (s, 6H).

Synthesis Example 4: Synthesis of Compound A25

Add raw material M (1000mmol, 1.0eq) and 2000ml dichloromethane to a 10L three-necked flask, and stir to dissolve. Control the temperature below 10℃, pour in 416mL of triethylamine (3000mmol, 3.0eq), control the temperature below 10℃, and drop 93.75g of hydrazine hydrate (1500mmol, 1.5eq). After the drop is complete, naturally warm up to room temperature, react for 1 hour, and monitor the reaction by TLC. Add 4000ml of pure water, stir for 30 minutes, and then filter; add the obtained solid to a 4000ml beaker containing 2000m of pure water, stir for 10 minutes, filter, and dry to obtain a white solid M1.

Benzaldehyde (175.8mmol, 1.1eq), M1 (159.8mmol, 1.0eq) and 1000ml ethanol were added to a single-mouth bottle, stirred until the solution was clear and then continued to stir for 30 minutes. The raw material disappeared after TLC monitoring. 57g (175.8mmol, 1.1eq) iodophenyl diacetic acid was added in batches. After the addition was completed, stirred for 1 hour. Solids gradually precipitated. After the reaction was completed after TLC monitoring, filtered, the filter cake was rinsed with ethanol until the filtrate was a colorless clear liquid to obtain brown solid M2.

In a reaction flask, add 100 mmol of M2, 100 mmol of M3, 40 g (300 mmol) of potassium carbonate, 800 ml of DMF, 200 ml of water, and then add 1% Pd(PPh ₃ ) ₄ , and react at 120°C for 12 hours. After the reaction is completed, stop the reaction, and the reactant is cooled to room temperature, added with water, filtered, washed with water, and the obtained solid is recrystallized and purified with toluene to obtain white powder A25. The amount of Pd(PPh ₃ ) ₄ added is 1 mol% of M2 and M3.

¹ H NMR (CDCl3, 400MHz) δ.8.40–8.33 (m, 6H), 8.28 (s, 2H), 8.18 (s, 1H), 8.07 (d, J = 12.0Hz, 2H), 7.78 (s, 1H) ),7.69(d,J=11.6Hz,2H),7.61(s,1H),7.50(m,9H),1.69(s,6H).

Other compounds of the present application can be synthesized by selecting suitable raw materials according to the ideas of the above Examples 1-4, or by selecting any other suitable method and raw materials for synthesis.

The second aspect of the present application also provides an organic electroluminescent device, which comprises the organic light-emitting material provided by the present application.

In the present application, there is no particular limitation on the method for preparing the OLED device, and the OLED device can be prepared using any method known in the art.

Example 1

The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, baked in a clean environment to completely remove the water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

The glass substrate with the anode is placed in a vacuum chamber, and the vacuum is evacuated to less than 10 ^-5 Torr. HT-11 is vacuum-deposited on the anode layer as a hole injection layer at a deposition rate of 0.1 nm/s and a deposition film thickness of 10 nm.

Vacuum evaporate HT-5 material on the hole injection layer as a hole transport layer, the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 80nm;

The light-emitting layer of the device is vacuum-deposited on the hole transport layer. The light-emitting layer includes a main material GHP-16 and a dye material RPD-1. The evaporation is performed by a multi-source co-evaporation method. The evaporation rate of the main material GHP-16 is adjusted to 0.1 nm/s, and the evaporation rate of the dye RPD-1 is adjusted to 3% of the evaporation rate of the main material. The total evaporation film thickness is 30 nm.

An electron transport layer is vacuum-deposited on the light-emitting layer. Material A2 is selected as the electron transport material. The evaporation rate is 0.1 nm/s and the total film thickness is 30 nm.

LiF with a thickness of 0.5 nm was vacuum evaporated on the electron transport layer (ETL) as an electron injection layer, and an Al layer with a thickness of 150 nm was used as the cathode of the device.

The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

At the same brightness, a digital source meter and a brightness meter were used to measure the driving voltage and current efficiency of the organic electroluminescent devices prepared in the embodiment and the comparative example, as well as the life of the devices. Specifically, the voltage was increased at a rate of 0.1 V per second, and the voltage when the brightness of the organic electroluminescent device reached 5000 cd/ ^m2 , i.e., the driving voltage, was measured, and the current density at this time was measured; the ratio of the brightness to the current density was the current efficiency; the life test of LT95 was as follows: a brightness meter was used to maintain a constant current at a brightness of 5000 cd/ ^m2 , and the time, in hours, for the brightness of the organic electroluminescent device to drop to 4750 cd/ ^m2 was measured.

Embodiment 2-6

The organic light-emitting materials A5, A13, A25, A27 and A35 of the present application are respectively used as electron transport materials, and the rest is the same as that of Example 1. The test results are shown in Table 1.

Comparative Example

R1 is used as the electron transport material, and the rest is the same as in Example 1. The test results are shown in Table 1.

Table 1 Performance results of organic electroluminescent devices

It can be seen from the data in the above table that the new organic material prepared in this application is used as an electron transport material for organic electroluminescent devices, which can effectively reduce the starting and ending voltage, improve the current efficiency, and extend the life of the device. It is an electron transport material with good performance.

Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims (3)

1. An organic light emitting material, wherein the organic light emitting material is selected from the group consisting of compounds shown below:

2. an organic electroluminescent device comprising the organic luminescent material according to claim 1.

3. The organic electroluminescent device according to claim 2, wherein the organic luminescent material is used as an electron transport material.