A compound, an organic electroluminescence device including the compound, a lighting or display device

Abstract

The present application relates to the technical field of organic photoelectric material preparation, and particularly relates to a compound, an organic electroluminescent device containing the compound, and an illumination or display device. The compound of the present application is used as a light-emitting auxiliary layer material, is obtained by using a dibenzofuran containing a limited aryl combination as a key group, is convenient for the evaporation process of a device, can effectively improve the light-emitting efficiency of an organic light-emitting device, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic optoelectronic material preparation, in particular to a compound, an organic electroluminescent device containing the compound, and a lighting or display device. BACKGROUND

[0002] An organic electroluminescent diode (OLED) is also known as an organic electroluminescent device. It is a technology that can convert electrical energy into light energy through organic light-emitting materials by applying a voltage to an organic electroluminescent element to inject holes from an anode and electrons from a cathode into a light-emitting layer, and then recombine the injected holes and electrons to form excitons to cause light emission.

[0003] At present, there are some defects in the light-emitting auxiliary layer materials applied in organic light-emitting devices, such as weak carrier transport capacity, low light-emitting efficiency, poor stability, and other problems. Some materials have complex preparation processes and high costs, and some materials have the phenomenon of easy aggregation quenching. The prior art uses the introduction of a dibenzofuran group in the material structure to improve the thermal stability of the material. However, the rigidity of the dibenzofuran molecular structure will have a certain impact on the film-forming property of the material and the compatibility with other functional layers.

[0004] Therefore, it is necessary to develop a vapor-deposable organic optoelectronic material with good evaporation stability and excellent film quality, and to find a suitable OLED optoelectronic functional material for OLED devices to solve the above problems. SUMMARY

[0005] To solve the above technical problems, the present application provides a compound, an organic electroluminescent device containing the compound, and a lighting or display device. The provided compound can maintain high stability and compatibility in the evaporation preparation process, and at the same time enable the device to have high efficiency.

[0006] The present application provides a compound, which is realized by the following technical scheme:

[0007] A compound has the structure of formula 1:

[0008] ;

[0009] Formula 1

[0010] L1 is independently selected from a single bond or C6-C30 arylene; Ar1 is independently selected from C6-C30 aryl or C5-C36 heteroaryl; the structure of formula 1 can be partially or completely deuterated.

[0011] Preferably, L1 is independently selected from a single bond, phenylene, naphthylene, and phenanthrylene.

[0012] Preferably, Ar1 is independently selected from the group consisting of dibenzofuranyl, dibenzothiophenyl, phenyl, biphenyl, naphthyl, phenanthryl, triphenylenyl.

[0013] According to one or more embodiments, the present application provides a compound selected from any one of the following chemical structures, wherein "D" represents:

[0014] .

[0015] The present application also provides a use of the compound as described above in the preparation of an organic electroluminescent device.

[0016] The present application also provides an organic electroluminescent device, comprising:

[0017] a substrate layer;

[0018] a first electrode on the substrate;

[0019] an organic light-emitting functional layer on the first electrode;

[0020] a second electrode on the organic light-emitting functional layer;

[0021] a cover layer on the second electrode;

[0022] the organic light-emitting functional layer comprises a light-emitting auxiliary layer, and the light-emitting auxiliary layer has the compound as described above.

[0023] Preferably, the organic light-emitting functional layer further comprises an electron transport layer, and the electron transport layer contains a triazine compound.

[0024] Preferably, the electron transport layer has the structure shown in formula II:

[0025] ;

[0026] In formula II, R1, R2 are each independently selected from hydrogen, cyano-substituted or unsubstituted C6-C30 aryl; L, L2, L3 are each independently selected from a single bond, cyano-substituted or unsubstituted C6-C30 aryl, and Ar is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C36 heteroaryl, when Ar is substituted, the substitution is selected from cyano, C6-C30 aryl.

[0027] Preferably, R1, R2 are each independently selected from hydrogen, cyano-substituted or unsubstituted phenyl, naphthyl.

[0028] Preferably, L, L2, L3 are each independently selected from a single bond, cyano-substituted or unsubstituted phenyl, biphenyl, terphenyl, naphthyl.

[0029] Preferably, Ar is independently selected from cyano-substituted phenyl, cyano-substituted naphthyl, phenyl-substituted pyridyl, phenyl-substituted triazinyl, spirofluorene-9,9-xanthene.

[0030] More preferably, the electron transport layer is selected from any one of the following structures:

[0031] .

[0032] The present application also provides a formulation comprising an organic compound having the structure of formula (I) as described above or the composition as described above and at least one solvent. The solvent is not particularly limited, and any of the solvents well known to those skilled in the art, such as unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, decalin, bicyclohexane, n-butylbenzene, sec-butylbenzene, t-butylbenzene, halogenated saturated hydrocarbon solvents such as carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, ether solvents such as tetrahydrofuran, tetrahydropyran, ester solvents such as benzoic acid alkyl ester, and the like can be used.

[0033] The organic electroluminescent device of the present application can be used in an OLED lighting or display device. The present application also provides a display or lighting device comprising one or more of the organic electroluminescent devices as described above.

[0034] In summary, compared with the prior art, the present application has the following beneficial effects:

[0035] The present application uses a compound containing a dibenzofuran with a defined aryl combination as a key group, so that the compound has excellent light-emitting efficiency and better evaporation stability; meanwhile, the compound provided by the present application is used in the light-emitting auxiliary layer of a device, facilitating the smooth progress of the evaporation process of the device, and effectively improving the light-emitting efficiency of the organic light-emitting device. DETAILED DESCRIPTION

[0036] The technical solutions of the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application.

[0037] The aryl group in the present application can comprise a monocyclic, fused ring or polycyclic structure, and can have a substituent group. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms, and more preferably 6 to 12 carbon atoms. The aryl group or aromatic group, as used herein, considers both non-fused and fused systems. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthyl, anthracenyl, pyrenyl, phenanthrenyl, fluorenyl, pyrenyl, perylenyl and azulenyl, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorenyl and naphthyl. 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.

[0038] The heteroaryl group in the present application refers to a group obtained by replacing one or more aromatic carbon atoms in an aryl group with a heteroatom, including but not limited to oxygen, sulfur, silicon or nitrogen atoms. The heteroaryl group can be a monocyclic heteroaryl group or a fused ring heteroaryl group, and can be a heteroaryl group having 4 to 36 carbon atoms, preferably 4 to 20 carbon atoms. Examples can include pyridyl, pyrrolyl, pyridyl, thienyl, furanyl, indolyl, quinolinyl, isoquinolinyl, benzothienyl, benzofuranyl, dibenzofuranyl, dibenzothienyl, carbazolyl, etc., but are not limited thereto.

[0039] Throughout this specification, unless expressly stated to the contrary, "comprising" means "comprehending, including, or encompassing, but not limited to, or in the nature of a 'including all equivalents'. Furthermore, it is to be understood that the terminology "on a", "on", or "over" with respect to positioning an element on or over another element, unless expressly stated to the contrary, means that the element can be "directly on" the other element, or intervening elements can also be present. In addition, "on" or "over" means positioned above the target portion, without necessarily being above in terms of gravitational direction.

[0040] It is an object of the present application to provide an organic electroluminescent device comprising: a substrate layer; a first electrode over the substrate; an organic light-emitting functional layer over the first electrode; a second electrode over the organic light-emitting functional layer; a cover layer over the second electrode; the organic light-emitting functional layer comprising a fixed combination of a defined material containing a dibenzofuran fragment as described herein.

[0041] In one embodiment of the present application, the light-emitting auxiliary layer in an organic electroluminescent (OLED) device comprises one or more components of the compounds as described above in general formula 1 as a light-emitting auxiliary layer material.

[0042] In one preferred embodiment of the present application, an OLED is provided, comprising a substrate, an anode, an organic light-emitting functional layer, a cathode, a cover layer, wherein the organic light-emitting functional layer can comprise a light-emitting layer, a light-emitting auxiliary layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, etc., and can also comprise only a light-emitting layer and one or more other layers; wherein the light-emitting auxiliary layer comprises one or more components of the compounds as described above in general formula (I). The cover layer is on the side of the cathode facing away from the organic light-emitting functional layer. Optionally, there is also a protective layer and / or an encapsulation layer on the cover layer.

[0043] In one preferred embodiment of the present application, the electron transport layer of the OLED contains a triazine compound. Further, the triazine compound has the structure of formula II. The electron transport layer can be selected from known or unknown materials, and in particular from the above-mentioned ET1-ET12 materials (commercially available), but does not mean that the present application is limited to the following structures.

[0044] The substrate of the present application can be any substrate used in typical organic light-emitting devices. It can be a glass or transparent plastic substrate, or a non-transparent material such as silicon or stainless steel substrate, or a flexible PI film. Different substrates have different mechanical strength, thermal stability, transparency, surface smoothness, water resistance, and the use direction is different according to the properties of the substrate.

[0045] As a material of the hole injection layer, the hole transport layer, the electron injection layer, and the light emitting layer, any material can be used from known related materials for an OLED device.

[0046] The present application will be described in detail below with reference to specific examples. All raw materials and solvents used in the synthesis examples were commercially available and used directly without further treatment, unless otherwise specified. Example

[0047] Example 1: Synthesis of Compound 1

[0048] Synthetic route:

[0049] ;

[0050] Synthetic method:

[0051] (1) Add S0 (10 mmoL), S1 (10 mmoL) to a reaction bottle, mix in a solution of dioxane: water (volume ratio 4:1) 10 mL, put into a 50 mL flask, reflux for 24 hours. Cool to room temperature, then slowly add saturated MgSO4 aqueous solution to the solution and extract with ethyl acetate three times, then remove the solvent from the organic layer by rotary evaporator, and obtain the product 1-1 by column chromatography;

[0052] (2) Add 1-1 (10 mmoL), 1-2 (12 mmoL), sodium tert-butoxide (12 mmoL) to a reaction bottle, 200 mL of toluene, replace with nitrogen, then add pd2(dba)3 (5×10 -2 mmoL), Sphos (5×10 -2 mmoL), heat to 100°C, reflux for 6 hours, stop the reaction. Cool to 30-40°C, add 200 mL of water, separate the layers. After washing with water twice, add n-heptane 100 mL after concentrating toluene, and beat the pulp. The intermediate product S2 is obtained;

[0053] (3) Add S2 (10 mmoL), 1-3 (12 mmoL), sodium tert-butoxide (12 mmoL) to a reaction bottle, 200 mL of toluene, replace with nitrogen, then add pd2(dba)3 (5×10 -2 mmoL), Sphos (5×10 -2 mmoL), heat to 100°C, reflux for 6 hours, stop the reaction. Cool to 30-40°C, add 200 mL of water, separate the layers. After washing with water twice, add n-heptane 100 mL after concentrating toluene, and beat the pulp. The target product 1 is obtained;

[0054] LC-MS (m / z): 653.56 (theoretical value: 653.24) was obtained by liquid chromatography-mass spectrometry analysis.

[0055] Example 2: Synthesis of compound 3

[0056] Referring to the synthesis steps and reaction conditions of Example 1, compound 3 was synthesized, and the difference from Example 1 was that the reactant 1-3 was changed to LC-MS (m / z): 703.76 (theoretical value: 703.25) was obtained by liquid chromatography-mass spectrometry analysis of the product.

[0057] Example 3: Synthesis of compound 8

[0058] Referring to the synthesis steps and reaction conditions of Example 1, compound 8 was synthesized, and the difference from Example 1 was that the reactant 1-3 was changed to LC-MS (m / z): 779.82 (theoretical value: 779.28) was obtained by liquid chromatography-mass spectrometry analysis of the product.

[0059] Example 4: Synthesis of compound 10

[0060] Referring to the synthesis steps and reaction conditions of Example 1, compound 10 was synthesized, and the difference from Example 1 was that the reactant 1-3 was changed to LC-MS (m / z): 779.80 (theoretical value: 779.28) was obtained by liquid chromatography-mass spectrometry analysis of the product.

[0061] Example 5: Synthesis of compound 12

[0062] Referring to the synthesis steps and reaction conditions of Example 1, compound 12 was synthesized, and the difference from Example 1 was that the reactant 1-3 was changed to LC-MS (m / z): 743.77 (theoretical value: 743.25) was obtained by liquid chromatography-mass spectrometry analysis of the product.

[0063] Example 6: Synthesis of compound 17

[0064] Referring to the synthesis steps and reaction conditions of Example 1, compound 17 was synthesized, and the difference from Example 1 was that the reactant 1-3 was changed to LC-MS (m / z): 759.84 (theoretical value: 759.22) was obtained by liquid chromatography-mass spectrometry analysis of the product.

[0065] Example 7: Synthesis of compound 20

[0066] Reference to the synthetic procedure and reaction conditions of Example 1, compound 20 was synthesized, with the difference that the reactant 1-3 was changed to The product was analyzed by LC-MS (m / z): the theoretical value was 803.28, and the tested value was 803.82.

[0067] Example 8: Synthesis of compound 21

[0068] Reference to the synthetic procedure and reaction conditions of Example 1, compound 21 was synthesized, with the difference that the reactant 1-3 was changed to The product was analyzed by LC-MS (m / z): the theoretical value was 829.30, and the tested value was 829.88.

[0069] Example 9: Synthesis of compound 25

[0070] Reference to the synthetic procedure and reaction conditions of Example 1, compound 25 was synthesized, with the difference that the synthetic route was changed to

[0071] ;

[0072] The product was analyzed by LC-MS (m / z): the theoretical value was 791.36, and the tested value was 791.90.

[0073] Example 10: Synthesis of compound 29

[0074] Reference to the synthetic procedure and reaction conditions of Example 1, compound 29 was synthesized, with the difference that the synthetic route was changed to

[0075] ;

[0076] The product was analyzed by LC-MS (m / z): the theoretical value was 790.35, and the tested value was 790.89.

[0077] The following are several application examples of the compound for light-emitting auxiliary layer according to the present application applied in OLED devices, to further illustrate the beneficial effects of the compound according to the present application. The materials used in the examples were purchased commercially or synthesized by the inventors.

[0078] Manufacture of OLED device:

[0079] As a reference preparation method of a device embodiment, the present application evaporates 50-500 nm of ITO / Ag / ITO (ITO:Ag:ITO weight ratio = 1: (10-20): 1) on an alkali-free glass substrate as an anode, evaporates a hole injection layer (5 nm-20 nm), a hole transport layer (50-150 nm), a light-emitting auxiliary layer (5-120 nm), a light-emitting layer (20-50 nm), a hole blocking layer (5-20 nm), an electron transport layer (20-80 nm), and an electron injection layer (1-10 nm) on the anode, co-evaporates Mg and Ag (weight ratio 1:9, 10-15 nm) to form a semi-transparent cathode, and then evaporates a cover layer compound (30 nm-90 nm). Finally, the light-emitting device is encapsulated with an epoxy resin adhesive in a nitrogen atmosphere.

[0080] In a preferred embodiment, the structure of the OLED device provided by the present application is as follows: first, the alkali-free glass substrate is washed with isopropyl alcohol for 15 minutes using an ultrasonic cleaner, and then subjected to UV ozone washing treatment in air for 30 minutes. The treated substrate is evaporated by vacuum evaporation method to evaporate ITO / Ag / ITO (ITO:Ag:ITO weight ratio = 1:10:1, 120 nm) as an anode, and then evaporate a hole injection layer (HT:PD, 10 nm, 2%), a hole transport layer (HT, 130 nm), a light-emitting auxiliary layer (compound 1, 5 nm), a blue light-emitting layer (host material: dopant material = BH:BD (weight ratio 98:2, 30 nm)), a hole blocking layer (HBL, 5 nm), an electron transport layer (ET6:Liq = 1:1, 30 nm), and an electron injection layer (Yb, 1 nm) on the anode in sequence. Co-evaporate Mg and Ag (weight ratio 1:9, 13 nm) to form a semi-transparent cathode, and then evaporate CPL (65 nm) as a cover layer. Finally, the light-emitting device is encapsulated with an epoxy resin adhesive in a nitrogen atmosphere, which is referred to as Application Example 1. The molecular structure of the related materials is shown below (particularly preferably selected from the following structures, but not limited to the following structures):

[0081]

[0082] Application Examples 2-10 and Comparative Example 1 are prepared by the method provided in Application Example 1 described above, with the only difference being that the compounds listed in Table 1 are used as light-emitting auxiliary materials instead of compound 1 in Application Example 1. The structures of Ref-1 and Ref-3 used are as follows: .

[0083] Performance evaluation of OLED devices:

[0084] Performance testing and device light-emitting performance characterization

[0085] The OLED device was tested for current at different voltages using a Keithley 2365A digital nanovoltmeter, and then the current was divided by the light-emitting area to obtain the current density of the OLED device at different voltages; the luminance and radiant energy flux density of the OLED device at different voltages were tested using a Konicaminolta CS-2000 spectroradiometric luminance meter; according to the current density and luminance of the OLED device at different voltages, the operating voltage Volt and current efficiency (cd / A) at the same current density (10 mA / cm 2 ) were obtained, and the Blue Index BI = E / CIEy refers to the blue light, and is also a parameter for measuring the blue light emission efficiency, E refers to the current efficiency, and CIEy refers to the ordinate color point obtained by inputting the half-peak width wavelength of the light emitted by the device into the CIE1930 software. The test data are shown in Table 1.

[0086] As can be seen from Table 1, the application examples 1 to 10 have higher blue light BI emission efficiency compared with the application comparative example 1. The performance improvement of each application example is based on the longer conjugated length of the arylamine upper side chain used in the present application, the system is extended through arylene buffering, and the electron supply ability is improved by increasing the dibenzofuran, thereby reducing the voltage and improving the light emission efficiency. It has better film forming stability, which can improve the light emission efficiency of the device and reduce the power consumption of the device.

[0087] It can be seen that the similar material of the application comparative example 2 has different sites, and the voltage, efficiency and lifetime performance are all reduced, and the reduction amplitude of the lifetime reaches 15%, which is very obvious in the field. The selection of this site is not a conventional adjustment, and the preferred compound obtained by the structure of the present application under this fixed site and fixed group segment can have excellent technical effects in device application.

[0088] The technical solution of the present application limits the compound general formula , and specifically limits L1 and Ar1. The connection site and connecting group of the two furans are specifically selected by fixing the segment containing dibenzofuran on both sides. The technical point is that the long chain dibenzofuran on one side can maintain the low voltage property of the compound; the dibenzofuran group on the other side is connected with the benzene ring at the ortho position, has larger steric hindrance, has good structure stereoisomerism, good film forming property, improves the lifetime, and has stronger power supply ability, and the ortho connection mode has better effect on the light emission efficiency of the material. The patent application of the applicant on the light emission auxiliary material is a result of continuous iteration of technology, belongs to a selection invention, and is based on continuous optimization and limitation to obtain the preferred compound of the present application, which can play an excellent role in device application.

[0089] Further, in order to verify the excellent performance of the combination compound provided by the present application, application examples 11-20 and comparative examples 3-6 were prepared according to the method provided in application example 1 described above; the only difference is that the compounds listed in Table 2 were used to replace ET7 or compound 1 in the device of application example 1, respectively. The structure of Ref-2 involved is as follows:

[0090] As can be seen from Table 2, the light-emitting auxiliary material in the present application is used in combination with the electron transport material, which can better achieve the balance of electron and hole transport and the exciton conversion rate, reduce the power consumption of the device, and improve the service life and light-emitting efficiency of the device.

[0091] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A compound, characterized in that, The compound is selected from any one of the following chemical structures, "D" represents deuterium:

2. Use of the compound of claim 1 in the preparation of an organic electroluminescent device.

3. An organic electroluminescent device, characterized by Comprising: a substrate layer; a first electrode over the substrate; an organic light-emitting functional layer over the first electrode; a second electrode over the organic light-emitting functional layer; a cover layer over the second electrode; the organic light-emitting functional layer comprises a light-emitting auxiliary layer, the light-emitting auxiliary layer has the compound of claim 1.

4. The organic electroluminescent device according to claim 3, characterized in that The organic light-emitting functional layer further comprises an electron transport layer, the electron transport layer has the structure shown in formula II: In formula II, R1, R2 are each independently selected from hydrogen, cyano-substituted or unsubstituted C6-C30 aryl; L, L2, L3 are each independently selected from a single bond, cyano-substituted or unsubstituted C6-C30 aryl, Ar is independently selected from cyano-substituted phenyl, cyano-substituted naphthyl, phenyl-substituted pyridyl, phenyl-substituted triazinyl, spirofluorene-9,9-xanthene.

5. The organic electroluminescent device according to claim 4, characterized in that The R1, R2 are each independently selected from hydrogen, cyano-substituted or unsubstituted phenyl, naphthyl.

6. The organic electroluminescent device according to claim 4, wherein The L, L2, L3 are each independently selected from a single bond, cyano-substituted or unsubstituted phenyl, biphenyl, terphenyl, naphthyl.

7. The organic electroluminescent device according to claim 4, wherein The electron transport layer is selected from any one of the following structures:

8. A formulation characterized in that, The preparation comprises the compound of claim 1 and at least one solvent.

9. A display or illumination device, characterized in that The device comprises the organic electroluminescent device of any one of claims 3-7.

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