Amine compound and organic electroluminescent device containing same

Abstract

The invention provides an amine compound containing an organic light-emitting device thereof, and the amine compound has a structure as shown in formula I. The amine compound provided by the invention can be used as a hole transport layer material of an OLED light-emitting device, so that the OLED light-emitting device has relatively low driving voltage, relatively high current efficiency and relatively long service life.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescence, and relates to an amine compound and an organic electroluminescence device containing the amine compound. Background Art

[0002] Organic electroluminescent (OLED) display technology is a new generation of display technology based on electroluminescence after CRT and LCD. As a new generation of display technology, it has the advantages of good display effect, low power consumption, high flexibility and ultra-thinness, and is widely used in mobile phones, cars, smart wearable devices and other product screens.

[0003] The basic device structure of OLED includes cathode, electron injection layer, electron transport layer, organic light-emitting layer, hole transport layer, hole injection layer, anode and substrate. The color of OLED light depends on the type of organic molecules in the light-emitting layer. Placing several organic films on the same OLED will form a color display. The brightness or intensity of light depends on the performance of the light-emitting material and the size of the applied current. For the same OLED, the greater the current, the higher the brightness of the light.

[0004] At present, various new organic electroluminescent materials with excellent performance have been developed one after another, but with the rapid development of information technology, people have also put forward new goals and requirements for the performance of information display systems, especially in terms of efficiency, life, voltage, etc. Therefore, how to design a new organic electroluminescent material to meet the needs of its use in high-performance OLED devices is a key research topic for researchers in this field. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an amine compound and an organic electroluminescent device containing the same. The present invention designs the compound structure and uses the compound as the main material of the hole transport layer of the OLED device, so that the OLED device has a lower driving voltage, higher current efficiency and longer life.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides an amine compound having a structure as shown in the following formula I:

[0008]

[0009] R1-R3 independently represent substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; X is selected from O or S.

[0010] Preferably, R1-R3 are phenyl, tolyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracenyl, peryl, fluoranthene, pyrenyl, phenylnaphthyl, naphthylphenyl, diphenylphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, benzyl, 9,9-spirobifluorenyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, dibenzofuranophenyl, dibenzothienophenyl, benzophenanthryl, spiro[fluorene-9,9'-xanthene], pyridyl, benzylphenyl, pyridylphenyl, indolyl, carbazole indolyl, fluorene carbazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, azadibenzofuranyl or azadibenzothienyl.

[0011] Preferably, the aryl or heteroaryl group is further an aryl or heteroaryl group substituted by a C1-C18 alkyl group.

[0012] Preferably, the amine compound includes but is not limited to any one of the following compounds:

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019] X is selected from O or S.

[0020] Preferably, the amine compound is selected from any one of compounds 1 to 12:

[0021]

[0022] In a second aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode; the material of the organic thin film layer comprises the amine compound as described in the first aspect.

[0023] As a preferred technical solution of the present invention, the organic thin film layer includes a hole transport layer; the material of the hole transport layer includes the amine compound as described in the first aspect.

[0024] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device described in the second aspect.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention obtains an amine compound with a specific structure by designing the structure of the amine compound. The amine compound provided by the present invention can be used as a main material of a hole transport layer of an OLED light-emitting device, so that the OLED light-emitting device has a lower driving voltage, a higher current efficiency and a longer life. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0028] Example 1

[0029] Synthesis of compound 1

[0030]

[0031] (1) Synthesis of Intermediate I

[0032] 0.1 mol of 1-bromo-7-chlorodibenzo[b,d]furan, 0.12 mol of o-nitrobenzene borate, 0.15 mol of potassium carbonate, 0.002 mol of tetrakis(triphenylphosphine)palladium, 300 mL of tetrahydrofuran, and 100 ml of water were added to a reaction flask, and heated to reflux for 6 h under nitrogen protection. After the reaction was completed, the reaction liquid was rotary evaporated to 100 ml, 200 ml of water was added, stirred for 30 min, filtered, the filter cake was washed with water once, washed with ethanol once, and then recrystallized with ethanol and toluene to obtain intermediate I.

[0033] The mass spectrum data of intermediate I was tested, and the mass spectrum m / z was measured to be 323.03.

[0034] (2) Synthesis of Intermediate II

[0035] 0.1 mol of intermediate I, 0.2 mol of triphenylphosphine and 300 mL of o-dichlorobenzene were added to a reaction flask, heated to reflux under nitrogen protection, and reacted for 12 h. When the reaction was complete, o-dichlorobenzene was directly distilled off under reduced pressure. 500 ml of toluene was added to the product in the reaction flask, heated to dissolve and passed through a silica gel column. The column liquid was concentrated to 100 ml, 200 ml of ethanol was added, and the mixture was stirred for 30 min and filtered to obtain intermediate II.

[0036] The mass spectrum data of intermediate II was tested, and the mass spectrum m / z was measured to be 291.05.

[0037] (3) Synthesis of Intermediate III

[0038] 0.1 mol of intermediate II, 0.13 mol of bromobenzene, 0.15 mol of potassium carbonate, 0.05 mol of cuprous bromide, 0.02 mol of o-phenanthroline, 0.03 mol of 18-crown ether-6, and 800 mL of dimethyl sulfoxide were added to the reaction bottle, and the reaction was carried out under nitrogen protection and temperature control at 140° C. for 12 h.

[0039] The reaction solution was cooled to below 50°C, poured into 800 mL of pure water, and 800 mL of toluene was added thereto. The reaction system was quenched with a 10% hydrochloric acid solution until it was neutral, stirred for 30 minutes, and allowed to stand for stratification. The lower aqueous phase was extracted twice with toluene, and the organic phases were combined and washed with water until neutral. The organic phase was concentrated until no solvent flowed out. 500 mL of ethanol was added and stirred for 1 hour, and the intermediate III was obtained by suction filtration.

[0040] The mass spectrometry detection of intermediate III showed m / z of 367.08.

[0041] (4) Synthesis of Compound 1

[0042] 0.1 mol of intermediate III, 0.11 mol of diphenylamine and 200 ml of xylene were added to a reaction flask, and nitrogen was evacuated 3 times. 20 ml of 10% tri-tert-butylphosphine solution (toluene solution) and 0.001 mol of Pd2(dba)3 were quickly dropped into the reaction flask, and then 0.12 mol of sodium tert-butoxide was quickly added. The reaction was heated to reflux for 12 h. After the reaction was completed, 400 ml of n-heptane was added to the reaction flask, stirred for 30 min, filtered, and the filter cake was washed twice with water and once with ethanol, and then recrystallized from toluene and ethanol to obtain compound 1.

[0043] The mass spectrometry of compound 1 showed an m / z of 500.19.

[0044] Example 2

[0045] Synthesis of compound 2

[0046]

[0047] The synthesis of compound 2 is similar to that of compound 1, except that diphenylamine is replaced with N-phenyl-[1,1'-biphenyl]-4-amine.

[0048] The mass spectrometry of compound 2 showed an m / z of 576.22.

[0049] Example 3

[0050] Synthesis of compound 3

[0051]

[0052] Synthesis of Intermediate IV

[0053] Similar to the synthesis of intermediate I in Example 1, except that 1-bromo-7-chlorodibenzo[b,d]furan was replaced with 1-bromo-7-chlorodibenzo[b,d]thiophene, intermediate IV was obtained.

[0054] The mass spectrometry detection of intermediate IV showed m / z of 339.01.

[0055] Synthesis of Intermediate V

[0056] The synthesis of intermediate II is similar to that of Example 1, except that intermediate I is replaced by intermediate IV to obtain intermediate V.

[0057] The mass spectrometry detection of intermediate V showed m / z of 307.02.

[0058] Synthesis of Intermediate VI

[0059] Similar to the synthesis of intermediate III in Example 1, except that intermediate II was replaced by intermediate V, intermediate VI was obtained.

[0060] The mass spectrometry detection of intermediate VI showed m / z of 383.05.

[0061] Synthesis of compound 3

[0062] The synthesis of compound 1 is similar to that of Example 1, except that intermediate III is replaced by intermediate VI and diphenylamine is replaced by N-phenylnaphthalene-2-amine to obtain compound 3.

[0063] The mass spectrometry of compound 3 showed an m / z of 566.18.

[0064] Example 4

[0065] Synthesis of compound 4

[0066]

[0067] The synthesis is similar to that of compound 1, except that diphenylamine is replaced with N-phenyldibenzo[b,d]furan-2-amine to obtain compound 4.

[0068] The mass spectrometry of compound 4 showed an m / z of 590.20.

[0069] Example 5

[0070] Synthesis of compound 5

[0071]

[0072] Synthesis of intermediate VII

[0073] The synthesis of intermediate III was similar, except that bromobenzene was replaced by 4-bromo-1,1'-biphenyl to give intermediate VII.

[0074] The mass spectrometry detection of intermediate VII showed m / z of 443.11.

[0075] Synthesis of compound 5

[0076] The synthesis of compound 5 is similar to that of compound 1, except that intermediate IV is replaced by intermediate VII and diphenylamine is replaced by di([1,1'-biphenyl]-4-yl)amine.

[0077] The mass spectrometry of compound 5 showed an m / z of 728.28.

[0078] As shown in Table 1, the preparation raw materials and mass spectrometry detection data of Compound 6-Compound 12 are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] Other compounds whose specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above embodiments.

[0083] The specific structures of the compounds used in the following device examples and device comparative examples are shown below:

[0084]

[0085] Device Example 1

[0086] This device embodiment provides an organic electroluminescent device, using the compound A provided in Synthesis Example 1 as a hole transport material in the organic electroluminescent device;

[0087] The structure of the organic electroluminescent device provided in the present device embodiment is: ITO / hole transport material (40nm) / EM1: BD-2 3% (30nm) / Alq3 (30nm) / LiF (0.5nm) / Al (150nm);

[0088] The organic electroluminescent device preparation process is as follows:

[0089] (1) a glass substrate coated with an ITO transparent conductive layer (as an anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, and then baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the properties of the surface and enhance the bonding ability with the hole layer;

[0090] (2) Place the glass substrate in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 ~1×10 -6 Pa, vacuum evaporation of part of the compound provided in the synthesis example of the present invention (see Table 2 for details) on the anode as an organic electroluminescent device as a hole transport layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 40nm;

[0091] (3) Vacuum evaporation of EM1 and BD-2 on the hole transport layer as the organic light-emitting layer of the device, the main material of the light-emitting layer: BD-2 3% (30nm) means that in the device, the main material of the light-emitting layer and BD-2 are co-evaporated in a volume ratio of 97:3 to form a light-emitting layer, and the thickness of the light-emitting layer is 30nm;

[0092] (4) vacuum evaporating Alq3 on the organic light-emitting layer as an electron transport layer of the organic electroluminescent device; the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm;

[0093] (5) 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer to serve as the electron injection layer and cathode.

[0094] Device Examples 2-12

[0095] Device Examples 2-12 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the hole transport material is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0096] Device Comparison Examples 1-3

[0097] Device Comparative Examples 1-3 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the hole transport material is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0098] Performance Test:

[0099] The brightness, driving voltage, current efficiency and life test LT90 of the organic electroluminescent device provided above are tested, wherein the life test LT90 refers to the current density at room temperature (25-27°C) at the initial brightness (1000 cd / m 2), the time required for the brightness to decrease to 90% of the initial brightness. In the following table, the driving voltage, current efficiency, and LT90 life are all relative values ​​(based on the test data of device comparative example 1). The test results are detailed in Table 2 below.

[0100] Table 2

[0101] Device Examples Hole transport materials Required brightness Driving voltage Current efficiency LT90 Device Comparison Example 1 E1 1000 1 1 1 Device Comparison Example 2 E2 1000 0.94 0.92 0.97 Device Comparison Example 3 E3 1000 1.01 1.06 0.91 Device Example 1 Compound 1 1000 0.82 1.58 2.13 Device Example 2 Compound 2 1000 0.9 1.53 2.09 Device Example 3 Compound 3 1000 0.89 1.68 2.01 Device Example 4 Compound 4 1000 0.56 1.55 1.19 Device Example 5 Compound 5 1000 0.76 1.58 4.1 Device Example 6 Compound 6 1000 0.74 1.65 2.3 Device Example 7 Compound 7 1000 0.77 1.63 3.21 Device Example 8 Compound 8 1000 0.74 1.79 3.28 Device Example 9 Compound 9 1000 0.81 1.65 2.23 Device Example 10 Compound 10 1000 0.78 1.68 2.25 Device Example 11 Compound 11 1000 0.84 1.64 4.21 Device Example 12 Compound 12 1000 0.92 1.59 2.17

[0102] It can be seen from the content of Table 2 that the present invention obtains an amine compound through molecular design. The amine compound provided by the present invention can be used as a hole transport material for an OLED light-emitting device, so that the OLED light-emitting device has a lower driving voltage, higher current efficiency and longer life.

[0103] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the amine compounds and the organic electroluminescent devices containing the same, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An amine compound, characterized in that The amine compound has a structure shown in the following formula I: R1-R3 independently represent substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; X is selected from O or S.

2. The amine compound according to claim 1, characterized in that R1-R3 are phenyl, tolyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracenyl, peryl, fluoranthene, pyrenyl, phenylnaphthyl, naphthylphenyl, diphenylphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, benzyl, 9,9-spirobifluorenyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, dibenzofuranophenyl, dibenzothienophenyl, triphenylene, spiro[fluorene-9,9'-xanthene], pyridyl, benzylphenyl, pyridylphenyl, indolyl, carbazole indolyl, fluorene carbazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, azadibenzofuranyl or azadibenzothienyl.

3. The amine compound according to claim 1, characterized in that The aryl or heteroaryl group is an aryl or heteroaryl group substituted by a C1-C18 alkyl group.

4. The amine compound according to any one of claims 1 to 3, characterized in that The amine compound is any one of the following compounds: Wherein, X is selected from O or S.

5. The amine compound according to any one of claims 1 to 4, characterized in that The amine compound is selected from any one of compounds 1 to 12:

6. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer disposed between the anode and the cathode; the material of the organic thin film layer comprises the amine compound according to any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, characterized in that: The organic thin film layer comprises a hole transport layer; the material of the hole transport layer comprises the amine compound as described in any one of claims 1-5.

8. A display device, characterized in that: The display device comprises the organic electroluminescent device according to claim 6 or 7.

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