An organic light-emitting material and an organic electroluminescent device

Abstract

The application provides an organic light-emitting material and an organic electroluminescent device, and has a compound, wherein Ar1-Ar3 are each independently selected from hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. The technical scheme of the application can be used as an electron transport material, and the OLED device matched with the electron transport material has good performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic electroluminescent devices, in particular, to an organic light-emitting material and an organic electroluminescent device having the same. BACKGROUND

[0002] Organic electroluminescent display (hereinafter referred to as OLED) has a series of advantages such as self-luminescence, low-voltage direct current driving, full solidification, wide viewing angle, light weight, simple composition and process, etc. Compared with liquid crystal display, organic electroluminescent display does not need a backlight source, has a large viewing angle, and low power consumption. The response speed of organic electroluminescent display can reach 1000 times of that of liquid crystal display, and the manufacturing cost thereof is lower than that of liquid crystal display with the same resolution. Therefore, organic electroluminescent device has a broad application prospect.

[0003] With the continuous advancement of OLED technology in the fields of lighting and display, people pay more attention to the research on high-efficiency organic materials affecting the performance of OLED devices. An organic electroluminescent device with good efficiency and long service life is usually the result of optimization of device structure and various organic materials.

[0004] In the most common OLED device structure, the following kinds of organic materials are usually included: hole injection material, hole transport material, electron transport material, and various luminescent materials (dye or doped guest material) and corresponding host materials, etc. The performance of the known electron transport material is not ideal, and the industry still needs to develop new electron transport materials.

[0005] Therefore, the present application provides an organic light-emitting material with low voltage, high efficiency and the like, and an organic electroluminescent device having the same. SUMMARY

[0006] In view of the problems in the prior art, the purpose of the present application is to provide an organic light-emitting material and an organic electroluminescent device having the same, which not only has a low voltage, but also has a high efficiency and a long service life.

[0007] According to one aspect of the present application, an organic light-emitting material is provided, which has a structure shown in Formula I:

[0008]

[0009] wherein Ar1-Ar3 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.

[0010] Preferably, Ar1-Ar3 are each independently selected from hydrogen, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C2-C 10alkenyl, substituted or unsubstituted C6-C 30 aryl or substituted or unsubstituted C3-C 30 heteroaryl.

[0011] Preferably, Ar1-Ar3 are each independently selected from substituted or unsubstituted C6-C 30 aryl or substituted or unsubstituted C3-C 30 heteroaryl.

[0012] Preferably, Ar1 is selected from substituted or unsubstituted C6-C 12 aryl.

[0013] Preferably, Ar1 is phenyl or biphenyl.

[0014] Preferably, Ar2 is selected from substituted or unsubstituted C6-C 12 aryl.

[0015] Preferably, Ar3 is selected from C6-C 12 aryl.

[0016] Preferably, the structure of Formula I is:

[0017]

[0018]

[0019] According to another aspect of the present application, there is also provided an organic electroluminescent device doped with the organic light-emitting material described above.

[0020] Preferably, the organic electroluminescent device contains the organic light-emitting material in the electron transport layer or the light-emitting layer.

[0021] The organic light-emitting material of the present application contains an O / N heterocyclic compound, which can form a stable heterocyclic organic aromatic system. The compound has the characteristics of nitrogen heterobenzene as the core, difficulty in crystallization between molecules, good film-forming properties, rich photoelectric properties, reversible electrochemical reduction reaction, suitable HOMO and LUMO energy levels, high electron mobility, good film-forming properties, high Tg, etc., which can make the device have the characteristics of high life, low voltage, etc. DETAILED DESCRIPTION

[0022] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example implementations to those skilled in the art.

[0023] In the embodiments of the present application, an organic light-emitting material and an organic electroluminescent device having the same are provided, and the compound having the structure shown in Formula I:

[0024]

[0025] wherein Ar1-Ar3 are each independently selected from hydrogen, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C2-C 10 alkenyl, substituted or unsubstituted C6-C 30 aryl, or substituted or unsubstituted C3-C 30 heteroaryl.

[0026] The organic light-emitting material and the organic electroluminescent device having the same in the embodiments of the present application adopt the O / N heterocyclic compound, can form a stable heterocyclic organic aromatic system, and thus have good stability, better efficiency, and can be used as an electron transport material. The OLED device matched therewith has good service life.

[0027] In the embodiments of the present application, the compound having the structure shown in Formula I is preferably:

[0028]

[0029]

[0030] The method for synthesizing the compound having the structure shown in Formula I is as follows, and those skilled in the art should know that the above preparation method is only an exemplary example, and thus the preparation method is not specifically limited, and only the following representative synthesis path is exemplarily provided. The compounds for which the preparation method is not provided can also be purchased, and thus will not be described in detail, and those skilled in the art can synthesize them according to the general compound synthesis method provided in the present application and the prior art, and will not have any difficulty.

[0031] The specific steps are as follows:

[0032] Step 1: Synthesis of intermediate product 2

[0033]

[0034] A two-necked flask of 200 mL containing a mixture of starting material A (5.0 mmol), starting material B (Ar1-B(OH)2, 10.0 mmol), potassium carbonate (10.0 mmol), and tetrakis triphenylphosphine palladium (0.25 mmol) was charged with dry toluene (70 mL) and water (35 mL) under nitrogen. The mixture was refluxed at 100-120 °C for 12-24 hours. After cooling to room temperature, the mixture was extracted with DCM / water. The combined organic layers were dried over magnesium sulfate, filtered and evaporated. The residue was purified by silica gel column chromatography, followed by recrystallization from toluene to obtain a solid compound, and the intermediate product 1 was obtained by purification by silica gel column chromatography.

[0035] The intermediate product 1 was brominated with NBS to obtain the intermediate product 2 after purification.

[0036] Step 2: Synthesis of intermediate product 3

[0037]

[0038] The intermediate product 2 (5.0 mmol), starting material C (Ar2-B(OH)2, 5.0 mmol), sodium tert-butoxide, tris-dibenzylideneacetone palladium, and tri-tert-butylphosphine were dissolved in 60 mL of toluene, stirred at 90 °C for 3 hours under nitrogen. After the reaction was completed, it was cooled to room temperature, extracted twice with dichloromethane and water, and the organic phase was evaporated with anhydrous magnesium sulfate, followed by column chromatography to obtain the intermediate product 3.

[0039] Step 3: Synthesis of intermediate product 4

[0040]

[0041] The starting material D (5.0 mmol), starting material E (Ar3-Br, 5.0 mmol), sodium tert-butoxide, tris-dibenzylideneacetone palladium, and tri-tert-butylphosphine were dissolved in 60 mL of toluene, stirred at 90 °C for 3 hours under nitrogen. After the reaction was completed, it was cooled to room temperature, extracted twice with dichloromethane and water, and the organic phase was evaporated with anhydrous magnesium sulfate, followed by column chromatography to obtain the intermediate product 4.

[0042] Step 4: Synthesis of Formula I

[0043]

[0044] The intermediate product 4 (5.0 mmol) and the intermediate product 3 (5.0 mmol), sodium tert-butoxide, tris-dibenzylideneacetone palladium, and tri-tert-butylphosphine were dissolved in 60 mL of toluene, stirred at 90 °C for 3 hours under nitrogen. After the reaction was completed, it was cooled to room temperature, extracted twice with dichloromethane and water, and the organic phase was evaporated with anhydrous magnesium sulfate, followed by column chromatography to obtain the target structure Formula I.

[0045] The present application is described in detail in the following specific examples:

[0046] Compound 1

[0047] The synthetic method for preparing Compound 1 is as follows:

[0048] Step 1: Synthesis of intermediate 1

[0049]

[0050] To a mixture of Formula A1 (5.0 mmol), B1 (10.0 mmol), potassium carbonate (10.0 mmol), tetrakis(triphenylphosphine)palladium (0.25 mmol) in a 200 mL two-necked flask under nitrogen was added dry toluene (70 mL) and water (35 mL). The mixture was refluxed at 100-120 °C for 12-24 hours. After cooling to room temperature, the mixture was extracted with DCM / water. The combined organic layers were dried over magnesium sulfate, filtered and evaporated. The residue was purified by silica gel column chromatography, followed by recrystallization from toluene to give solid compound, which was purified by silica gel column chromatography to give the intermediate 1, yield 80%.

[0051] Step 2: Synthesis of intermediate 3

[0052]

[0053] The intermediate 1 was brominated by NBS, and after purification, the intermediate 2 was obtained.

[0054] The intermediate 2 (5.0 mmol), starting material C1 (5.0 mmol), sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were dissolved in 60 ml of toluene, protected by nitrogen, and stirred at 90 °C for 3 hours. After the reaction was completed, it was cooled to room temperature, extracted twice with dichloromethane and water, and the organic phase was evaporated with anhydrous magnesium sulfate, followed by column chromatography to obtain the intermediate 3, with a yield of 75%.

[0055] Step 3: Synthesis of Compound 1

[0056]

[0057] The intermediate 3 (5.0 mmol), starting material D1 (i.e. intermediate 4, 5.0 mmol), sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were dissolved in 60 ml of toluene, protected by nitrogen, and stirred at 90 °C for 3 hours. After the reaction was completed, it was cooled to room temperature, extracted twice with dichloromethane and water, and the organic phase was evaporated with anhydrous magnesium sulfate, followed by column chromatography to obtain Compound 1, with a yield of 75%.

[0058] In a similar manner, Compounds 1-5 can be prepared, as shown in Table 1 below.

[0059] Table 1: Compound synthesis table (since the starting material A is the same, it is omitted)

[0060]

[0061]

[0062] The compounds 1-5 all have high mobility and suitable energy level, and can be used as electron transport materials; the compound of the present application also has high thermal stability, which ensures the thermal stability of the material in the evaporation process.

[0063] Control test

[0064] Examples 1-5

[0065] The organic light emitting elements 1-5 are prepared by using the compounds 1-5 prepared by the present application respectively.

[0066] The ITO anode layer on the transparent substrate layer is cleaned, and is ultrasonically cleaned with deionized water, acetone and ethanol respectively for 15 minutes, and then is treated in a plasma cleaner for 2 minutes.

[0067] The following layer structure is evaporated by vacuum evaporation: a hole injection layer of 10 nm thick HAT-CN material;

[0068] A hole transport layer of 70 nm thick NPB material;

[0069] An emitting layer is evaporated on the hole transport layer, GH is used as the host material, and Ir(ppy)3 is used as the doping material with a mass ratio of 1:9, and the thickness is 30 nm;

[0070] The compounds 1-5 of the present application are evaporated as electron transport materials on the emitting layer respectively, and the thickness is 40 nm, and this layer of organic material is used as a hole blocking / electron transport layer;

[0071] An electron injection layer LiF is evaporated on the hole blocking layer / electron transport layer, and the thickness is 1 nm, and this layer is an electron injection; a cathode Al (100 nm) is vacuum evaporated on the electron injection layer.

[0072] Comparative example 1

[0073] An organic light emitting element 6 is prepared. The difference between the organic light emitting element 6 and the organic light emitting elements 1-5 prepared by using the compounds 1-5 is that the following formula TPBI is used instead of the compounds 1-5 as the electron transport material in the organic light emitting element 6, and the rest is the same.

[0074] The related molecular formula structure is shown as follows:

[0075]

[0076] Performance test

[0077] The organic light emitting devices 1-5 prepared in Examples 1-5 of the present application and the organic light emitting device 6 prepared in Comparative Example 1 were subjected to the following performance tests:

[0078] The OLEDs were characterized in a standard way. For this purpose, electroluminescence spectra, power efficiency (measured in cd / A) and voltage (in V) were determined from current-voltage-luminance characteristics (JUL characteristics). For selected tests, the lifetime was determined. The lifetime is defined as the time after which the luminance has dropped from a certain starting luminance to a certain fraction. The number T95 means that the specified lifetime is the time at which the luminance has dropped to 95% of the starting luminance, i.e. from 1000 cd / m2 to 950 cd / m2, for example. Depending on the emission color, different starting luminances were chosen. Lifetime values can be converted to values for other starting luminances by means of conversion formulas known to the person skilled in the art.

[0079] The results of the performance tests are shown in Table 2:

[0080] Table 2: Test results

[0081]

[0082] From the performance data in Table 2, it can be seen that the compounds provided by the present application, when used as electron transport materials for organic electroluminescent devices, provide devices with higher device efficiency, lower operating voltage and longer service life.

[0083] In summary, the organic light emitting material of the present application and the organic electroluminescent device having the same not only have a lower voltage, but also have a higher efficiency.

[0084] The above content is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For those of ordinary skill in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can also be made, which should be considered to fall within the protection scope of the present application.

Claims

1. An organic light-emitting material, characterized in that, It has the structure shown in Equation I: Formula I Ar1-Ar3 are each independently selected from C6-C 30 Aryl groups.

2. The organic light-emitting material according to claim 1, characterized in that: The Ar1 is selected from C6-C. 12 Aryl groups.

3. The organic light-emitting material according to claim 2, characterized in that: Ar1 is a phenyl or biphenyl.

4. The organic light-emitting material according to claim 1, characterized in that: The Ar2 is selected from C6-C. 12 Aryl groups.

5. The organic light-emitting material according to claim 1, characterized in that: The Ar3 is selected from C6-C. 12 Aryl groups.

6. An organic light-emitting material, characterized in that: It has the following structure: 、 , , , , or .

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device is doped with the organic light-emitting material according to any one of claims 1-6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic light-emitting material is contained in the electron transport layer of the organic electroluminescent device.

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