An organic light-emitting compound, an OLED having the compound, and an organic light-emitting device

Abstract

The present invention relates to the technical field of organic optoelectronic materials, in particular to an organic light-emitting compound, an OLED having the compound, and an organic light-emitting device. The organic light-emitting compound of the present invention is provided with a triazine structure as a core aromatic group for substitution on both sides, and a central structure is a group having a fused aromatic group or a fused heteroaromatic group combined with a cyano group, so that the compound has excellent luminous efficiency and good thermal stability; at the same time, the organic light-emitting compound provided by the present invention is used for devices, especially for electron transport layer materials, which can effectively make the organic light-emitting device have a lower driving voltage and maintain voltage stability, and the luminous efficiency is improved, and the working life is significantly extended, which has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of organic photoelectric materials, and in particular to an organic light-emitting compound, an OLED having the compound, and an organic light-emitting device. Background Art

[0002] Organic light-emitting diodes (OLEDs), also known as organic electroluminescent devices, are a technology that applies voltage to organic electroluminescent elements to inject holes from the anode and electrons from the cathode into the light-emitting layer respectively. The injected holes and electrons recombine to form excitons, resulting in luminescence. It can convert electrical energy into light energy through organic light-emitting materials.

[0003] In organic electroluminescent devices, since the carrier migration speed of holes in most materials does not match that of electrons, the two carriers are unlikely to recombine in the light-emitting layer, which will lead to a decrease in the photoelectric performance of the device, and an increase in leakage current, causing the device to heat up and reduce the device life. Existing materials are still insufficient in improving device performance. Even if different combinations of multiple materials are used, display technology still has problems such as high driving voltage and short display life, which seriously affects the further practical application of this technology.

[0004] Therefore, it is necessary to continue to work hard to develop organic light-emitting devices with low voltage drive, high brightness and long life, and to find suitable OLED optoelectronic functional materials for OLED devices to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an organic light-emitting compound, an OLED having the compound, and a display or lighting device. The provided compound has triazine structures as core aromatic groups on both sides for substitution, and the central structure is a group having fused aromatic groups or fused heteroaromatic groups combined with cyano groups for matching, so that the organic light-emitting compound is used in an organic electroluminescent device, so that the device can have both high efficiency and long service life.

[0006] The present invention provides an organic light-emitting compound, which is realized by the following technical solution:

[0007] An organic light-emitting compound, wherein the organic light-emitting compound has a structure as shown in the following formula I:

[0008] ;

[0009] In Formula I, R 1 , R 2 are each independently selected from hydrogen or cyano, and R 1 , R 2 One of them is cyano; Ar 1 ,Ar2 Each is independently selected from C6-C30 aryl; L 1 , L 2 are each independently selected from phenyl, naphthyl, dibenzofuranyl or dibenzothienyl, and L 1 , L 2 At least one of them is selected from naphthyl, dibenzofuranyl and dibenzothiophenyl; the hydrogen atoms in the structure shown in Formula I may be partially or completely deuterated.

[0010] Preferably, in the formula I, Ar 1 ,Ar 2 Each is independently selected from phenyl, biphenyl and naphthyl.

[0011] According to one or more embodiments, the present invention provides an organic light-emitting compound selected from any one of the chemical structures shown below, wherein D represents deuterium:

[0012]

[0013] The present invention also provides a use of the organic light-emitting compound as described above in an organic electroluminescent device.

[0014] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising:

[0015] substrate layer;

[0016] a first electrode, the first electrode being on the substrate;

[0017] An organic light-emitting functional layer, the organic light-emitting functional layer is on the first electrode;

[0018] A second electrode, the second electrode being on the organic light-emitting functional layer;

[0019] The organic light-emitting functional layer includes the organic light-emitting compound as described above.

[0020] Preferably, the organic light-emitting functional layer includes an electron transport layer, and the electron transport layer contains the organic light-emitting compound as described above.

[0021] The present invention also provides a composition, which comprises the organic light-emitting compound as described in Formula I.

[0022] The present invention also provides a preparation, which comprises an organic light-emitting compound having a structure as shown in the above formula I or a composition as described above and at least one solvent. The solvent is not particularly limited, and can be used, for example, unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexane, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, butyl chloride, butyl bromide, pentyl chloride, pentyl bromide, hexyl chloride, hexyl bromide, cyclohexyl chloride, cyclohexyl bromide, halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, ether solvents such as tetrahydrofuran, tetrahydropyran, and ester solvents such as alkyl benzoate.

[0023] The organic electroluminescent device of the present invention can be used in an OLED lighting or display device.

[0024] The present invention also provides a display or lighting device, which comprises one or more of the organic electroluminescent devices described above.

[0025] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0026] The central structure of the organic light-emitting compound provided by the present invention defines a cyano-substituted phenyl group and an adjacent substituted fused aromatic group as fixed matching groups, and the two sides are substituted with a triazine structure as the core aromatic group, so that the compound has excellent luminous efficiency and a good service life; at the same time, the organic light-emitting compound provided by the present invention is used in a device, especially as an electron transport layer material to prepare a device, which can effectively make the organic light-emitting device have a lower driving voltage and maintain voltage stability, and the luminous efficiency is improved, and the working life of the device can also be better. DETAILED DESCRIPTION

[0027] The following will be described clearly and completely in conjunction with the technical solutions of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] The aryl group of the present invention refers to a general term for a monovalent group after removing a hydrogen atom from the aromatic core carbon of an aromatic hydrocarbon molecule, which can be a monocyclic aryl group or a condensed ring aryl group. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples may include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthyl, anthracenyl, phenanthrenyl or pyrenyl, but are not limited thereto. Aryl or aromatic group-as used herein, non-condensed and condensed systems are considered. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of the aryl group include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthrene, phenanthrene, fluorene, pyrene, perylene and azulene, with preference given to phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. Examples of non-fused aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenyl, 4"-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl and m-quaterphenyl.

[0029] The heteroaryl group of the present invention refers to a general term for a group obtained by replacing one or more aromatic carbon atoms in an aromatic group with a heteroatom, wherein the heteroatom includes but is not limited to oxygen, sulfur, silicon or nitrogen atoms, and the heteroaryl group may be a monocyclic heteroaryl group or a condensed ring heteroaryl group, and may be a heteroaryl group having 6 to 30 carbon atoms, preferably a heteroaryl group having 6 to 20 carbon atoms. Examples may include pyridyl, pyrrolyl, pyridyl, thienyl, furanyl, indolyl, quinolyl, isoquinolyl, benzothienyl, benzofuranyl, dibenzofuranyl, dibenzothienyl, carbazolyl, etc., but are not limited thereto.

[0030] Throughout the specification, unless explicitly described to the contrary, "comprising" any component will be understood to imply the inclusion of other elements, rather than excluding any other elements. In addition, it should be understood that throughout the specification, when an element such as a layer, film, region or substrate is referred to as being "on" or "above" another element, it can be "directly on" another element, or there may be intervening elements. In addition, "on..." or "above..." means being located above the target portion, and does not necessarily mean being located above according to the direction of gravity.

[0031] An object of the present invention is to provide an organic electroluminescent device, which includes: a substrate layer; a first electrode, which is on the substrate; an organic light-emitting functional layer, which is on the first electrode; a second electrode, which is on the organic light-emitting functional layer; the organic light-emitting functional layer includes an electron transport layer. In one embodiment of the present invention, the electron transport layer in the organic electroluminescent (OLED) device contains one or more of the compounds shown in the above general formula I.

[0032] In a preferred embodiment of the present invention, an OLED is provided, which includes a substrate, an anode, a cathode, and an organic light-emitting functional layer, wherein the organic light-emitting functional layer may include a light-emitting layer, a light-emitting auxiliary layer, a hole transport layer, a hole injection layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc., or may only include a light-emitting layer and one or more other layers; wherein the electron transport layer may contain one or more of the compounds represented by the above general formula I. Optionally, there is a covering layer, a protective layer and / or an encapsulation layer on the organic light-emitting functional layer.

[0033] The substrate of the present invention can be any substrate used in a typical organic light-emitting device. It can be a glass or transparent plastic substrate, or a substrate of an opaque material such as silicon or stainless steel, or a flexible PI film. Different substrates have different mechanical strengths, thermal stability, transparency, surface smoothness, and waterproofness. Depending on the properties of the substrate, the use direction is different.

[0034] As materials for the hole injection layer, the hole transport layer, the electron injection layer, and the light emitting layer, any material can be selected from known related materials used for OLED devices.

[0035] The present invention is described in detail below in conjunction with specific examples. Synthesis Examples All raw materials and solvents are commercially available unless otherwise specified, and the solvents are used directly without further treatment.

[0036] Example

[0037] Example 1: Synthesis of Compound 3

[0038] Synthesis route:

[0039] ;

[0040] Synthesis method:

[0041] 1) 3-1 (10 mmoL), 3-2 (6 mmoL), Pd(dppf)Cl 2 (5×10 - 2 mmoL) 、K 2 CO 3 (9mmoL) was added to 10mL of dioxane: water (mass ratio 4:1), mixed, placed in a 50mL flask, and refluxed for 24 hours. Cooled to room temperature, and then saturated MgSO 4 The solution was extracted with aqueous solution and ethyl acetate three times, and then the organic layer was subjected to a rotary evaporator to remove the solvent, and then subjected to column chromatography to obtain compound 3;

[0042] The structure of the test target product compound 3: LC-MS (m / z) was obtained by liquid chromatography-mass spectrometry analysis: the theoretical value was 767.28, and the test value was 767.88.

[0043] Example 2: Synthesis of Compound 30

[0044] Referring to the synthesis steps and reaction conditions of Example 1, compound 30 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 783.38 and the test value was 783.96.

[0045] Example 3: Synthesis of Compound 42

[0046] Referring to the synthesis steps and reaction conditions of Example 1, compound 42 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 817.30 and the test value was 817.92.

[0047] Example 4: Synthesis of Compound 61

[0048] Referring to the synthesis steps and reaction conditions of Example 1, compound 61 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 817.30 and the test value was 817.88.

[0049] Example 5: Synthesis of Compound 68

[0050] Referring to the synthesis steps and reaction conditions of Example 1, compound 68 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 843.31 and the test value was 843.95.

[0051] Example 6: Synthesis of Compound 75

[0052] Referring to the synthesis steps and reaction conditions of Example 1, compound 75 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 843.31 and the test value was 843.93.

[0053] Example 7: Synthesis of Compound 88

[0054] Compound 88 was synthesized by referring to the synthesis steps and reaction conditions of Example 1. The LC-MS (m / z) was analyzed by liquid chromatography-mass spectrometry: the theoretical value was 807.27 and the test value was 807.91.

[0055] Example 8: Synthesis of Compound 116

[0056] Referring to the synthesis steps and reaction conditions of Example 1, compound 116 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 823.25 and the test value was 823.95.

[0057] Example 9: Synthesis of Compound 136

[0058] Referring to the synthesis steps and reaction conditions of Example 1, compound 136 was synthesized and analyzed by liquid chromatography-mass spectrometry to obtain LC-MS (m / z): the theoretical value was 857.29 and the test value was 857.93.

[0059] Several examples of the application of the organic light-emitting compound of the present invention in OLED devices are listed below to further illustrate the beneficial effects of the compound of the present invention. The materials used in the examples are purchased from commercial sources or synthesized by the user.

[0060] Fabrication of OLED devices:

[0061] As a reference preparation method for a device embodiment, the present invention evaporates 50-500nm ITO / Ag / ITO on an alkali-free glass substrate as an anode, evaporates a hole injection layer (5nm-20nm), a hole transport layer (50-150nm), a light-emitting auxiliary layer (5-120nm), a light-emitting layer (20-50nm), a hole blocking layer (5-20nm), an electron transport layer (20-80nm), and an electron injection layer (1-10nm) on the anode, and then co-evaporates Mg and Ag (weight ratio 1:9, 10-50nm) to make a semi-transparent cathode, and then evaporates a cover layer compound. Finally, the light-emitting device is encapsulated using an epoxy resin adhesive in a nitrogen atmosphere.

[0062] In a preferred embodiment, the structure of the OLED device provided by the present invention is as follows: first, an alkali-free glass substrate is washed with isopropanol using an ultrasonic cleaner for 15 minutes, and then a UV ozone cleaning treatment is performed in the air for 30 minutes. The treated substrate is vacuum-deposited with ITO / Ag / ITO 100nm as an anode, and then a hole injection layer (HT:PD, 10nm, 2%), a hole transport layer (HT, 130nm), a light-emitting auxiliary layer (BP, 5nm), a blue light-emitting layer (main material: doping material = BH:BD (weight ratio 98:2, 30nm)), a hole blocking layer (HBL, 5nm), an electron transport layer (compound 3:Liq=1:1, 30nm), and an electron injection layer (Yb, 1nm) are sequentially stacked and evaporated, and Mg and Ag (weight ratio 1:9, 14nm) are co-evaporated to make a semi-transparent cathode, and then a compound CPL (65nm) is evaporated as a covering layer. Finally, the light emitting device is encapsulated with epoxy resin adhesive in a nitrogen atmosphere, which is recorded as Application Example 1. The molecular structure formula of the relevant material is as follows (particularly preferably selected from the following structure, but it does not mean that the present invention is limited to the following structure):

[0064] The method provided in the above-mentioned application example 1 was used to prepare application examples 2 to 9 and comparative example 1, the only difference being that the compounds listed in Table 1 were used as hole blocking materials to replace compound 3 in application example 1. The structure of Ref-1 used in the comparative example is as follows: .

[0065] Performance evaluation of OLED devices:

[0066] The current of the OLED device at different voltages was tested using a Keithley 2365A digital nanovoltmeter, and the current was then divided by the luminous area to obtain the current density of the OLED device at different voltages. The brightness and radiant energy flux density of the OLED device at different voltages were tested using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED device at different voltages, the current density (10 mA / cm 2 ) working voltage Volt and current efficiency (cd / A), BI=E / CIEy, refers to the Blue Index in blue light, and is also a parameter for measuring the luminous efficiency of blue light. E refers to the current efficiency, and CIEy refers to the vertical coordinate color point obtained by bringing the wavelength of the device's luminous half-peak width into the CIE1930 software. The test data is shown in Table 1.

[0067] Table 1 Application examples of hole blocking materials and their electronic luminescence properties

[0068]

[0069] As can be seen from Table 1, compared with Comparative Example 1, Application Examples 1 to 9 have lower operating voltage, higher BI luminous efficiency and longer service life. The performance improvement of each application example is based on the fact that the organic light-emitting compound of the present invention has a dendritic molecule with a triazine structure as the core, and the nitrogen-containing heterocyclic ring has a strong electron-withdrawing ability and a large conjugated plane, so that the compound has good thermal stability and a high glass transition temperature, and the service life of the device is improved; at the same time, by limiting the relationship between the connection site of the cyano group on the phenyl group and the site of the connected fused aromatic group, the luminescent properties of the compound can be greatly affected, thereby improving the luminous efficiency of the device, and can better achieve the balance of electron and hole transmission and the exciton conversion rate, and reduce the power consumption of the device.

[0070] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An organic light-emitting compound, characterized in that: The organic light-emitting compound has a structure as shown in the following formula I: In Formula I, R1 and R2 are each independently selected from hydrogen or cyano, and one of R1 and R2 is cyano; Ar1 ​​and Ar2 are each independently selected from C6-C30 aryl; L1 and L2 are each independently selected from phenyl, naphthyl, dibenzofuranyl or dibenzothiophenyl, and at least one of L1 and L2 is selected from dibenzofuranyl and dibenzothiophenyl; the hydrogen atoms in the structure shown in Formula I may be partially or fully deuterated.

2. The organic light-emitting compound according to claim 1, characterized in that: In the formula I, Ar1 and Ar2 are each independently selected from phenyl, biphenyl and naphthyl.

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

4. A preparation, characterized in that The preparation comprises the organic light-emitting compound according to any one of claims 1 to 3 and at least one solvent.

5. A composition, characterized in that The composition comprises the organic light-emitting compound as described in any one of claims 1 to 3.

6. Use of the organic light-emitting compound according to any one of claims 1 to 3 in the preparation of an organic electroluminescent device.

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises: substrate layer; a first electrode, the first electrode being on the substrate; An organic light-emitting functional layer, the organic light-emitting functional layer is on the first electrode; A second electrode, the second electrode being on the organic light-emitting functional layer; The organic light-emitting functional layer comprises the organic light-emitting compound according to any one of claims 1 to 3.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic light-emitting functional layer includes an electron transport layer, and the electron transport layer contains the organic light-emitting compound according to any one of claims 1 to 3.

9. Use of the organic electroluminescent device according to claim 7 or 8 in a display or lighting device.

10. A display or lighting device, characterized in that: The device comprises the organic electroluminescent device as claimed in claim 7 or 8.

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