Organic compounds and organic layers and their applications, organic electroluminescent devices, display or lighting devices

Abstract

This application discloses an organic compound and an organic layer, their applications, an organic electroluminescent device, and a display or lighting device, wherein the organic compound has the structural formula shown in Formula I: In Formula I, L1 and L2 are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; Ar1, Ar2, and Ar3 are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups. X is selected from O, S, NR1, CR2R3, and SiR4R5, and R1 to R5 are independently selected from substituted or unsubstituted straight-chain or branched C1 to C30 alkyl groups, substituted or unsubstituted C3 to C30 cycloalkyl groups, substituted or unsubstituted C1 to C30 heteroalkyl groups, substituted or unsubstituted C1 to C30 heterocycloalkyl groups, substituted or unsubstituted C6 to C30 aryl groups, substituted or unsubstituted C3 to C30 heteroaryl groups, or formed into a ring with adjacent atoms. When this organic compound is applied to organic electroluminescent devices, it can significantly improve the current efficiency and lifetime of the device and reduce the operating voltage of the device.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescent materials technology, specifically to an organic compound and organic layer and their applications, organic electroluminescent devices, and display or lighting devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have attracted much attention due to their thin profile, high brightness emission at low driving voltages, and ability to emit multiple colors by selecting appropriate light-emitting materials. With the large-scale application of OLEDs, the demand for OLED functional materials is also increasing.

[0003] Many OLED functional materials have been developed, but when organic electroluminescent devices are fabricated using these materials, the device performance still needs to be improved. Therefore, further research and development of OLED functional materials is still required. Summary of the Invention

[0004] The purpose of this application is to provide an organic compound and organic layer and their applications, organic electroluminescent devices, display or lighting devices, which can significantly improve the current efficiency and lifespan of organic electroluminescent devices and reduce the operating voltage of the devices.

[0005] To achieve the above objectives, the present application provides an organic compound with the structural formula shown in Formula I: In Formula I, L1 and L2 are independently selected from substituted or unsubstituted C6-C30 arylene groups and substituted or unsubstituted C3-C30 heteroarylene groups; Ar1, Ar2 and Ar3 are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; X is selected from O, S, NR1, CR2R3, SiR4R5, and R1-R5 are independently selected from substituted or unsubstituted straight-chain or branched C1-C30 alkyl groups, substituted or unsubstituted C3-C30 cycloalkyl groups, substituted or unsubstituted C1-C30 heteroalkyl groups, substituted or unsubstituted C1-C30 heterocycloalkyl groups, substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, or cyclic groups formed with adjacent atoms.

[0006] In some embodiments of this application, L1 and L2 are independently selected from one or more of the following groups, whether substituted or unsubstituted: phenylene, biphenylene, naphthylene, phenanthrene, spirofluorene, dibenzofuranyl, dibenzothiophene, carbazoyl, triphenylene, 9,9-dimethylfluorene, and 9,9-diphenylfluorene.

[0007] In some embodiments of this application, Ar1, Ar2, and Ar3 are independently selected from the following groups, either substituted or unsubstituted: phenyl, biphenyl, naphthyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiophenyl, carbazoleyl, or formed into a ring with adjacent atoms.

[0008] In some embodiments of this application, R1 to R5 are independently selected from methyl, phenyl, phenoxy, carbazole, or formed into a ring with adjacent atoms.

[0009] In some embodiments of this application, the structural formula of the organic compound is selected from formula H1 to H160; wherein, L2 is independently selected from phenylene, biphenylene, naphthylene, and dibenzofuranylene; and Ar2 and Ar3 are independently selected from one or a combination of several of phenyl, naphthyl, dibenzofuranyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, and spirofluorenyl.

[0010] In some embodiments of this application, the organic compound is selected from compound 1 to compound 30.

[0011] This application also provides an organic layer comprising any of the organic compounds mentioned above.

[0012] This application also provides the use of any of the foregoing organic compounds and / or the foregoing organic layers in organic electroluminescent devices.

[0013] This application also provides an organic electroluminescent device, including a first electrode, a second electrode, and the aforementioned organic layer, wherein the organic layer is at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron injection layer, or an electron transport layer.

[0014] This application also provides a display or lighting device, including the aforementioned organic electroluminescent device.

[0015] Compared with the prior art, the organic compound of this application uses an aryl alkyl diamine system as the parent nucleus. There is an aryl group between the aryl alkyl structural fragment and the nitrogen atom of the diamine system, which makes the organic compound molecule have a strong conjugation effect, thereby making the material more stable and the migration of electrons and holes more balanced. Therefore, when this organic compound is used to prepare organic electroluminescent devices, the current efficiency and lifetime of the device can be greatly improved, while the operating voltage of the device can be reduced. Attached Figure Description

[0016] The following accompanying drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals denote similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting and exemplary, and the drawings are for illustrative purposes only and are not intended to limit the scope of this application. Other embodiments may similarly fulfill the inventive intent of this application. It should be understood that the drawings are not drawn to scale. Wherein:

[0017] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device of Embodiment 31 of this application. Detailed Implementation

[0018] The following description provides specific application scenarios and requirements for this application, intended to enable those skilled in the art to make and use the content of this application. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this application. Therefore, this application is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0019] During their research, the inventors discovered that while arylbenzoalkyl monoamine systems can improve device lifetime when used as the host nucleus, current efficiency needs further improvement. However, when a specific arylbenzoalkyl diamine system is used as the host nucleus, both current efficiency and lifetime are improved. Further research into this specific arylbenzoalkyl diamine system revealed that the presence of an aryl group between the arylbenzoalkyl group and the nitrogen atom in the diamine system increases the conjugation effect, making the material more stable and improving the balance of electron and hole migration, thereby significantly enhancing both current efficiency and lifetime. Furthermore, the alkyl group in the arylbenzoalkyl group of this application is specifically substituted with a dimethyl group, balancing current efficiency and thermal stability.

[0020] Examples of substituents appearing in this application are described below, but the substituents are not limited to these:

[0021] Substituted or unsubstituted: refers to substitution by one or more substituents selected from the following: deuterium, halogen group, nitrile group, nitro group, hydroxyl group, carbonyl group, ester group, imide group, amino group, phosphine oxide group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, silyl group, boron group, straight-chain or branched or cyclic alkyl group, alkenyl group, aryl group, aralkyl group, aryl-alkenyl group, alkylaryl group, alkylamine group, aralkylamine group, heteroarylamine group, arylamine group, arylphosphinyl group, heterocyclic group, or unsubstituted; or substitution by a substituent that connects two or more substituents from the examples above, or unsubstituted. For example, "substituent that connects two or more substituents" can include biphenyl, i.e., biphenyl can be aryl, or a substituent that connects two phenyl groups. The straight-chain, branched, or cyclic alkyl group is preferably a C1-C30 alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, methyl-substituted isobutyl, methyl-substituted tert-butyl, etc.

[0022] Aryl group: Not particularly limited; the aryl group can be monocyclic or polycyclic. In some embodiments, monocyclic aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, tetraphenyl, and pentaphenyl. Polycyclic aryl groups include, but are not limited to, naphthyl, anthracene, phenanthryl, pyrene, perylene, and fluorene. The fluorene group can be substituted, such as 9,9'-dimethylfluorenel or fluorenel. Furthermore, two of the substituents can combine with each other to form a spirocyclic structure, such as 9,9'-spirodifluorenel.

[0023] The above description of aryl can be applied to arylene, the difference being that arylene is divalent.

[0024] The above description of aryl groups can be applied to aryl groups in the following categories: aryloxy, arylthio, arylsulfonyl, arylphosphinyl, aralkyl, arylalkylamine, arylenyl, alkylaryl, arylamine, and arylheteroarylamine.

[0025] Heterocyclic groups: Containing one or more of B, N, O, P, S, Si, and Se as heteroatoms. Heterocyclic groups include, but are not limited to, pyridinyl, pyrrolyl, pyrimidinyl, pyridazinyl, furanyl, thiopheneyl, imidazolyl, pyrazolyl, azole, isozolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, dithiazolyl, tetrazolyl, pyranyl, thiaranyl, pyrazinyl, azinyl, thiazolyl, dioxazinyl, dioxazinyl, triazinyl, tetraazinyl, quinolinyl, isoquinolinyl, quinolinyl, quinazolinyl, quinoxalinyl, naphridinyl, acridineyl, xanthonyl, phenanthridineyl, diazanaphthyl, triazaindyl, indoleyl, dihydroindoleyl, nitric acid indole, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, etc. Pyrazinopyrazinyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, benzothiopheneyl, dibenzothiopheneyl, dibenzofuranyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indocarbazolyl, phenazinyl, imidazopyridyl, phenazinyl, phenanthrinyl, phenanthiazinyl, imidazopyridyl, imidazophenanthrinyl, benzimidazoquinazolinyl, benzimidazophenanthrinyl, spiro[fluorene-9,9'-oxazanthracene], phenylbinaphthyl, dinaphthofuranyl, naphthenofuranyl, dinaphthiopheneyl, naphthenopheneyl, triphenylphosphine oxide, triphenylborane, etc.

[0026] The above description of heterocyclic groups can be applied to heteroaryl groups, the difference being that heteroaryl groups are aromatic.

[0027] The above description of heterocyclic groups can be applied to heteroaryl, heteroarylamine, and heteroaryl-heteroarylamine groups.

[0028] The above description of heterocyclic groups can be applied to heteroaryl groups, the difference being that heteroaryl groups are divalent.

[0029] Alkyl groups can be straight-chain, branched, or cyclic, and there is no particular limitation on the number of carbon atoms. In some embodiments, alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 4-methylhexyl, 5-methylhexyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, etc.

[0030] The above description of alkyl groups can be applied to alkyl thio, alkyl sulfonyl, aralkyl, aralkylamine, alkylaryl, and alkylamine groups.

[0031] One aspect of this application provides an organic compound having the structural formula shown in Formula I: In Formula I, L1 and L2 are independently selected from substituted or unsubstituted C6-C30 arylene groups and substituted or unsubstituted C3-C30 heteroarylene groups. It should be noted that the diamine system... Substitution can occur at any substituted position on the connected benzene ring. Ar1, Ar2, and Ar3 are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups. X is selected from O, S, NR1, CR2R3, and SiR4R5, and R1-R5 are independently selected from substituted or unsubstituted straight-chain or branched C1-C30 alkyl groups, substituted or unsubstituted C3-C30 cycloalkyl groups, substituted or unsubstituted C1-C30 heteroalkyl groups, substituted or unsubstituted C1-C30 heterocycloalkyl groups, substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, or to form a ring with adjacent atomic bonds. In some embodiments, X is CR2R3, and R2 and R3 bonds form a ring. In some embodiments, X is SiR4R5, and R4 and R5 bonds form a ring.

[0032] In some embodiments, L1 and L2 are independently selected from one or more of the following groups, either substituted or unsubstituted: phenylene, biphenylene, naphthylene, phenanthrene, spirofluorene, dibenzofuranyl, dibenzothiophene, carbazoyl, triphenylene, 9,9-dimethylfluorene, and 9,9-diphenylfluorene.

[0033] In some embodiments, Ar1, Ar2, and Ar3 are independently selected from substituted or unsubstituted groups of the following: phenyl, biphenyl, naphthyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiopheneyl, carbazoyl, or bonded to adjacent atoms to form a ring, for example, any two groups of Ar1, Ar2, and Ar3 can bond to form a substituted or unsubstituted spirofluorenoxanthracene.

[0034] In some embodiments, R1 to R5 are independently selected from methyl, phenyl, phenoxy, carbazole, or formed into a ring with adjacent atoms.

[0035] In some preferred embodiments, X is selected from O, S, or the following structures: * indicates a connection site.

[0036] In some preferred embodiments, the structural formula of the organic compound is selected from the group consisting of:

[0037]

[0038]

[0039]

[0040]

[0041] In formulas H1 to H160 above, L2 is independently selected from phenylene, biphenylene, naphthylene, and dibenzofuranylene. Ar2 and Ar3 are independently selected from one or a combination of several of phenyl, naphthyl, dibenzofuranyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, and spirofluorenyl. As an example, at least one of Ar2 and Ar3 can be a combination of phenyl and 9,9-dimethylfluorenyl, for example...

[0042] In some preferred embodiments, the organic compound is selected from the group consisting of:

[0043]

[0044]

[0045] This application also provides an organic layer comprising any of the aforementioned organic compounds. The aforementioned organic compounds and the organic layer can be used in organic electroluminescent devices.

[0046] This application also provides an organic electroluminescent device, comprising a first electrode, a second electrode, and the aforementioned organic layer. As an example, the first electrode is an anode, and the second electrode is a cathode, wherein the cathode may be one or more layers. The organic layer is located between the first electrode and the second electrode. The organic layer may be a single-layer structure or a multilayer tandem structure with two or more organic layers laminated together. The organic layer is at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron injection layer, or an electron transport layer.

[0047] In some specific embodiments, the structure of the organic electroluminescent device may be selected from one of the following:

[0048] (1) An organic electroluminescent device includes an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode stacked in sequence, that is, anode / hole injection layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode. The device structure will be expressed in this simplified way below.

[0049] (2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode.

[0050] (3) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0051] (4) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode.

[0052] (5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode.

[0053] (6) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0054] (7) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0055] (8) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0056] (9) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0057] (10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode.

[0058] (11) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0059] (12) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / electron transport layer / cathode.

[0060] The organic electroluminescent device can emit light from either the anode side or the cathode side. In some specific embodiments, it emits light from the cathode side, which requires adding a capping layer on the cathode side, as shown in the following structure:

[0061] 1) Anode / hole injection layer / first hole transport layer / light emission layer / first electron transport layer / cathode / capping layer.

[0062] 2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode / capping layer.

[0063] 3) Anode / hole injection layer / second hole transport layer / first hole transport layer / light emission layer / first electron transport layer / second electron transport layer / cathode / capping layer.

[0064] 4) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode / capping layer.

[0065] 5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode / capping layer.

[0066] 6) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode / capping layer.

[0067] 7) Anode / Hole Injection Layer / First Hole Transport Layer / First Light Emitting Layer / Carrier Generation Layer / First Hole Transport Layer / Second Light Emitting Layer / First Electron Transport Layer / Second Electron Transport Layer / Cathode / Covering Layer.

[0068] 8) Anode / Hole Injection Layer / Second Hole Transport Layer / First Hole Transport Layer / First Light Emitting Layer / Carrier Generation Layer / First Hole Transport Layer / Second Light Emitting Layer / First Electron Transport Layer / Cathode / Covering Layer.

[0069] 9) Anode / Hole Injection Layer / Second Hole Transport Layer / First Hole Transport Layer / First Light Emitting Layer / Carrier Generation Layer / First Hole Transport Layer / Second Light Emitting Layer / First Electron Transport Layer / Second Electron Transport Layer / Cathode / Covering Layer.

[0070] 10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode / capping layer.

[0071] 11) Anode / Hole injection layer / First hole transport layer / Second hole transport layer / Light emission layer / Hole blocking layer / Electron transport layer / Cathode / Covering layer.

[0072] 12) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / cathode / capping layer.

[0073] The following describes some specific functional layers in the organic electroluminescent device.

[0074] Substrate:

[0075] The substrate is generally located below the anode. The substrate can be made of plastic or glass, and can be rigid or flexible. The substrate has a driving unit that can drive the corresponding pixel to emit light.

[0076] anode:

[0077] Organic EL (Organic Electro-Luminescence) devices typically require the anode to have good conductivity, a smooth surface, and be resistant to cracking. They also have certain requirements for work function, mainly to match the hole injection layer and achieve the hole injection effect.

[0078] When using a top-emitting method (cathode-side light emission), the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 200 nm, preferably 10 nm to 50 nm. A reflective electrode is placed below the anode (near the substrate end). The reflective electrode is generally made of metal or metal alloy, such as silver, copper, aluminum, gold, or alloys of these metals with other metals. The reflective electrode has high reflectivity, requiring a reflectivity of over 90%, and its thickness is typically between 100 nm and 500 nm, preferably in the range of 80 nm to 150 nm.

[0079] When bottom-emitting (light emission from the cathode side) is used, the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 1 μm, preferably 50 nm to 200 nm.

[0080] The anode can be made by forming a thin film from the electrode material using methods such as vapor deposition, sputtering, or coating.

[0081] Hole injection layer:

[0082] The thickness of the hole injection layer is typically 3 nm to 20 nm. The hole injection layer uses a mixture of P-type and hole transport materials. The purpose of using P-type materials is to accept holes from the anode and transfer them to the hole transport material. The weight percentage of P-type materials in the hole injection layer is typically 0.5% to 10%. When the weight percentage is 0.5% to 3%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.3 eV. When the weight percentage is 3% to 5%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.5 eV. When the weight percentage is 5% to 10%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 1 eV.

[0083] P-type materials can be metal oxides, such as molybdenum oxide, vanadium oxide, and tungsten oxide; they can also be organic compounds, such as 4,4',4”-((1E,1'E,1”E)-cyclopropane-1,2,3-trimethylenetris(cyanoformyl))tris(2,3,5,6-tetrafluorobenzyl) (PD1, CAS No.: 1224447-88-4), tetracyanoquinone dimethyl (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethyl (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), and are not limited to these. The hole transport material paired with the P-type material can be selected from the material of the second hole transport layer, and can be the same as or different from the material of the second hole transport layer.

[0084] Second hole transport layer:

[0085] The thickness of the second hole transport layer is typically 40 nm to 150 nm, and it often uses aryl amine compounds, such as monoaryl amines or polyaryl amines. Hole transport materials are required to have high hole mobility, reduce driving voltage, and have a glass transition temperature exceeding 100°C to avoid crystallization at high temperatures.

[0086] First hole transport layer:

[0087] The thickness of the first hole transport layer is typically 3nm to 220nm. When there is no second hole transport layer, the thickness of the first hole transport layer is typically 40nm to 150nm; when there is a second hole transport layer, the thickness of the first hole transport layer is typically 3nm to 120nm. Generally, red, green, blue, and yellow light require thickness adjustments based on the "microcavity effect," and the thickness selection varies accordingly.

[0088] Taking a top-emitting light-emitting device as an example, the formula for the microcavity is as follows:

[0089]

[0090] Where n i ,d i The refractive index coefficient and thickness of the i-th layer are respectively identified, m is an integer and is the modulus of the microcavity, which is more commonly 1 or 2; θ1 and θ2 represent the phase shifts generated by light at the anode and cathode interfaces, respectively.

[0091] Red, green, blue, and other colored light have different wavelengths, so each color has its optimal thickness. Taking a modulus of 2 as an example, for red light, without a second hole transport layer, the thickness of the first hole transport layer is typically 160nm–220nm; with a second hole transport layer, the thickness is typically 8nm–120nm. For green light, without a second hole transport layer, the thickness of the first hole transport layer is typically 100nm–180nm; with a second hole transport layer, the thickness is typically 30nm–70nm. For blue light, without a second hole transport layer, the thickness of the first hole transport layer is typically 80nm–130nm; with a second hole transport layer, the thickness is typically 3nm–30nm. Different colors will have different optimal "microcavity adjustment thicknesses."

[0092] Electron blocking layer:

[0093] The electron blocking layer can simultaneously possess both hole transport and electron blocking functions. Furthermore, the higher triplet excitation energy level of the electron blocking layer can confine excitons generated in the emissive layer within it, thereby improving the device's luminous efficiency.

[0094] Emissive layer:

[0095] The material of the light-emitting layer generally includes a host material and a guest dopant material, wherein the content of the host material is greater than that of the guest dopant material. Optionally, the mass percentage of the guest dopant material in the light-emitting layer is 1% to 20%.

[0096] Guest dopants used as luminescent materials can include phosphorescent or fluorescent materials or thermally activated delayed fluorescence materials. Red, green, and blue light can be selected from these three types of guest dopants. For example, the guest dopant material for the luminescent layer corresponding to a red luminescent unit and the luminescent layer corresponding to a green luminescent unit is a phosphorescent material, while the guest dopant material for the luminescent layer corresponding to a blue luminescent unit is a fluorescent material.

[0097] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a phosphorescent material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a phosphorescent material.

[0098] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a thermally activated delayed fluorescence material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a fluorescent material.

[0099] For example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a red emission color and the light-emitting layer corresponding to the light-emitting unit with a green emission color is a thermally activated delayed fluorescence material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with a blue emission color is a phosphorescent material.

[0100] To reduce the power consumption of organic light-emitting display panels in organic electroluminescent devices, guest doping materials with superior luminescent properties can be selected. Taking a top-emitting device as an example, optionally, the light-emitting unit with a red emission color has a luminous intensity of 1000 cd / m². 2 A green light-emitting unit with a current efficiency greater than 30 cd / A and a luminous intensity of 6000 cd / m² is used. 2 A light-emitting unit with a current efficiency greater than 100 cd / A and a fluorescent blue emission color has a luminous intensity of 1000 cd / m². 2 With a current efficiency greater than 5 cd / A as the standard, and by selecting suitable guest doping materials, a phosphorescent blue emitting unit is achieved with a luminous intensity of 1000 cd / m². 2 The standard is a current efficiency greater than 10 cd / A. Higher current efficiency can reduce power consumption.

[0101] It should be noted that one or two light-emitting materials can be selected as the main light-emitting material.

[0102] First electron transport layer:

[0103] The thickness of the first electron transport layer can typically be 3nm–40nm, 3nm–10nm, 10nm–20nm, 20nm–30nm, 30nm–40nm, or 20nm–40nm. When there is no second electron transport layer, the thickness of the first electron transport layer is typically 20nm–50nm; when there is a second electron transport layer, the thickness of the first electron transport layer is typically 40nm–20nm. The first electron transport layer is in direct contact with the emitting layer, and therefore, similar to the first hole transport layer, it also undergoes electronic changes during electron transport, leading to increased molecular vibration and deformation. Furthermore, the interaction between the excitons of the emitting layer and the polarons of the electron transport material can easily generate reactive free radicals, which can damage the electron transport material. The electron transport material can be a single compound or a mixture with other metals or metal compounds, such as Liq. It can include mixtures of organic electron transport materials and metal compounds, or mixtures of organic electron transport materials and metals.

[0104] When organic electron transport materials are mixed with metal compound materials, such as alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, they can be mixed with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and even more specifically, they can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When used in combination with metal compounds, the mass percentage of the organic electron transport material can be 20%–80%, 20%–40%, 40%–60%, or 60%–80%, etc.

[0105] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, and rare earth metals, or more specifically, with lithium metal, magnesium metal, calcium metal, ytterbium metal, and samarium metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0106] Second electron transport layer:

[0107] The thickness of the second electron transport layer is generally 10 nm to 40 nm. The material of the second electron transport layer may include a mixture of organic electron transport materials and metal compounds, or a mixture of organic electron transport materials and metals.

[0108] When organic electron transport materials are mixed with metal compound materials, such as alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, they can be mixed with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and even more specifically, they can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When used in combination with metal compounds, the mass percentage of the organic electron transport material can be 20%–80%, 20%–40%, 40%–60%, or 60%–80%, etc.

[0109] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, and rare earth metals, or more specifically, with lithium metal, magnesium metal, calcium metal, ytterbium metal, and samarium metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0110] Charge generation layer:

[0111] When a single-layer light-emitting device is used, holes and electrons are injected from the anode and cathode respectively, eliminating the need for a charge generation layer. When using double or multiple light-emitting layers, a charge generation layer is required between the light-emitting layers to achieve charge generation, injection, and transport. This charge generation layer is located between the two light-emitting layers and is typically composed of two P / N type materials. The P-type material is selected from the hole injection materials mentioned earlier, while the N-type material is a mixture of organic electron transport materials and metals. The organic electron transport layer material is selected from the second electron transport layer mentioned earlier, and the metal is selected from alkali metals, alkaline earth metals, and rare earth metals. More specifically, examples include lithium, magnesium, calcium, ytterbium, and samarium. When organic electron transport materials are mixed with metals, the mass percentage of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0112] cathode:

[0113] The cathode requires materials with good electrical conductivity and a smooth surface. To improve electron injection capability, materials with a low work function are typically chosen. Cathode materials can be single-layer, double-layer, or multi-layer cathodes, generally made of metals or metal alloys. For single-layer cathodes, silver, copper, aluminum, gold, or alloys of these metals with other metals, such as rare earth metals, alkali metals, and alkaline earth metals, can be used. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. If a double-layer metal cathode is used, the cathode layer closer to the light-emitting layer can be made of alkali metals, alkaline earth metals, or rare earth metals, such as lithium, calcium, magnesium, and ytterbium, to increase electron injection capability. The cathode layer farther from the light-emitting side is mainly used to improve conductivity, and generally uses silver, copper, aluminum, gold, or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals, or alkaline earth metals. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. The cathode can also be formed into a thin film using methods such as vapor deposition or sputtering.

[0114] When light comes out from the anode side, the cathode must be opaque, and a cathode with a thickness greater than 100 nm can be deposited. When light comes out from the cathode side, the cathode must be transparent, with a transmittance greater than 40% and a thickness of 10 nm to 20 nm.

[0115] Overlay:

[0116] The refractive index n and absorption coefficient of a single-layer capping layer must meet the following conditions:

[0117] The refractive index n(450~650nm) is >1.8 between wavelengths of 450~650nm, and the extinction coefficient between wavelengths of 450~650nm is less than 0.1; the extinction coefficient at 380nm is greater than 0.2; the difference between the refractive index at 450nm and the refractive index at 530nm is n(450nm)-n(530nm)<0.5, more preferably n(450nm)-n(530nm)<0.3; the difference between the refractive index at 510nm and the refractive index at 620nm is n(510nm)-n(620nm)<0.4, more preferably the difference between the refractive index at 510nm and the refractive index at 620nm is n(510nm)-n(620nm)<0.2.

[0118] Materials that can meet the requirements of the covering layer for refractive index n can further achieve high luminous efficiency of the device, while the luminous efficiency and viewing angle of red, green and blue light are more balanced.

[0119] In some specific embodiments, the thickness of the cover layer is 50nm to 90nm, for example, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0120] The cover layer is formed after the semi-transparent cathode of the OLED display panel is away from the substrate, and the stack formed by the cover layer and the semi-transparent cathode can achieve a light transmittance of ≥65% for light between 450nm and 650nm, such as 68%, 69%, 73%, 77%, 79%, 83%, 88%, 93%, etc.

[0121] When using two capping layers, the refractive index n and absorption coefficient need to satisfy the following conditions:

[0122] The refractive index n450-650nm<1.8 in the 450-650nm wavelength range of the capping layer (first capping layer) near the cathode side, and the extinction coefficient in the 450-650nm wavelength range is less than 0.1; the maximum coefficient in any wavelength range of 250nm-350nm is greater than 0.3, and the optimal value is greater than 0.6.

[0123] The refractive index n450-650nm > 1.8 in the 450-650nm wavelength range of the cover layer (second cover layer) away from the cathode side, and the extinction coefficient in the 450-650nm wavelength range is below 0.1; the extinction coefficient at 380nm is greater than 0.1, and more preferably greater than 0.2.

[0124] The difference between the refractive index of 450nm and the refractive index of 530nm, n(450nm)-n(530nm)<0.5, is more preferably n(450nm)-n(530nm)<0.3.

[0125] The difference between the refractive index of 510nm and 620nm, n(510nm)-n(620nm)<0.4, is even better than the difference between the refractive index of 450nm and 530nm, n(450nm)-n(530nm)<0.2.

[0126] The total thickness of the double-layer capping layer is 50nm to 90nm, for example: 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0127] The thickness of the capping layer (first capping layer) near the cathode side is 5nm to 40nm, for example: 5nm, 7nm, 10nm, 12nm, 15nm, 18nm, 20nm, 22nm, 25nm, 27nm, 30nm, 32nm, 34nm, 36nm, 38nm, 40nm, etc.

[0128] The thickness of the capping layer (second capping layer) away from the cathode side is 35nm to 85nm, for example: 35nm, 40nm, 43nm, 45nm, 48nm, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, etc.

[0129] This application also provides a display or lighting device, including the aforementioned organic electroluminescent device.

[0130] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional methods and conditions, or conditions recommended by the manufacturer, or the product instructions shall be followed. Unless otherwise stated, all parts are parts by weight, and all percentages are weight percentages.

[0131] The synthesis of the organic compounds described in this application can be carried out using known methods. For example, cross-coupling reactions of transition metals such as nickel and palladium can be used, as well as CC-CN coupling reactions of transition metals such as magnesium or zinc. Considering the mild reaction conditions and excellent selectivity of various functional groups, the Suzuki-Buchwald reaction is preferred. The initial raw materials and solvents in the following examples were purchased from Jiangsu Sanyue Optoelectronics Co., Ltd., and some commonly used OLED intermediates were purchased from domestic OLED intermediate manufacturers; various palladium catalysts and ligands were purchased from Sigma-Aldrich. HPLC data were determined using a Shimadzu LC 20AD high-performance liquid chromatograph, and LC-MS (liquid chromatography-mass spectrometry) was performed on a Waters Corporation H-class+SQD2 instrument.

[0132] Example 1

[0133] Synthesis of Compound 1

[0134]

[0135] 1) Synthesis of intermediate 1-1

[0136] Under an argon atmosphere, 19.1 g (100 mmol) of compound 1-A, 37.0 g (100 mmol) of compound 1-B, 23.4 g (240 mmol) of sodium tert-butoxide, 575 mg (1 mmol%) of palladium dibenzylacetone, 348 mg (1.2 mmol%) of tritert-butylphosphine tetrafluoroborate, and 1000 mL of xylene were added to a reaction vessel. The mixture was heated and stirred at 140 °C for 15 hours. The reaction mixture was cooled to room temperature, 1000 mL of water was added, and the mixture was filtered. The filter cake was washed with copious amounts of water, dried under vacuum, and the crude product was purified by silica gel column chromatography (eluent: ethyl acetate / hexane) to give 38.9 g of intermediate 1-1, with an HPLC purity of 99.6% and a yield of 81%. LCMS: M / Z 479.20 (M+).

[0137] 2) Synthesis of intermediates 1-2

[0138] Except for replacing the reactants with intermediate 1-1 and compound 1-C, the synthesis was identical to that of intermediate 1-1, with a yield of 76% and an HPLC purity of 99.7%. LC MS: M / Z 555.23 (M+).

[0139] 3) Synthesis of intermediates 1-3

[0140] Except for replacing the reactants with intermediates 1-2, compound 1-D, and the ligand with XPhos, the synthesis was identical to that of intermediate 1-1, with a yield of 74% and an HPLC purity of 99.7%. LC MS: M / Z 612.31 (M+).

[0141] 4) Synthesis of Compound 1

[0142] Except for replacing the reactants with intermediates 1-3 and compound 1-E, the synthesis was identical to that of intermediate 1-1, with a yield of 70% and HPLC purity of 99.9%. LC MS: M / Z 778.36 (M+).

[0143] Examples 2 to 30

[0144] The product compounds shown in the table below were prepared according to the synthesis method of Example 1.

[0145] Table 1. Product compounds, their synthetic raw materials, and yields.

[0146]

[0147]

[0148]

[0149]

[0150] Example 31

[0151] refer to Figure 1 The method for preparing the organic electroluminescent device in this embodiment includes:

[0152] (1) A 150 nm thick transparent anode ITO film is formed on a glass substrate 101 by magnetron sputtering to obtain the first electrode as the anode 102.

[0153] (2) A mixture of compound D-1 and compound D-2 is deposited on the surface of anode 102 as hole injection layer 103 with a mixing ratio of 3:97 (mass ratio) and a thickness of 10 nm.

[0154] (3) Compound D-2 of 100 nm and Compound 1 prepared in Example 1 of 40 nm were sequentially deposited on the hole injection layer 103 to obtain the first hole transport layer 104 and the second hole transport layer 105, respectively.

[0155] (4) On the second hole transport layer 105, compounds D-3, D-4 and D-5 are co-deposited in a mass ratio of 45:45:10 to form an organic light-emitting layer 106 with a thickness of 40 nm.

[0156] (5) A hole blocking layer 107 of 10 nm is formed by vapor deposition of compound D-6 on organic light-emitting layer 106.

[0157] (6) A 30 nm electron transport layer 108 is formed by vapor deposition of compound D-7 and LiQ in a mass ratio of 4:6 on hole blocking layer 107.

[0158] (6) Magnesium (Mg) and silver (Ag) are mixed and deposited on the electron transport layer 108 at a vapor deposition rate of 1:9 to form a 10 nm second electrode 109 as a cathode, thus completing the fabrication of the organic electroluminescent device.

[0159] Examples 32 to 60

[0160] Except that, when forming the second hole transport layer, compounds 2 to 30 prepared in Examples 2 to 30 were used to replace compound 1, the organic electroluminescent device was prepared using the same method as in Example 31.

[0161] Comparative Examples 1 to 4

[0162] Except that when forming the second hole transport layer, compound 1 was replaced with compounds HT-A, HT-B, HT-C and HT-D respectively, the organic electroluminescent device was prepared using the same method as in Example 31.

[0163] The compounds involved in the preparation of organic electroluminescent devices in Examples 31 to 60 and Comparative Examples 1 to 4 are as follows:

[0164] Table 2. Structural formulas of compounds

[0165]

[0166]

[0167] The organic electroluminescent devices prepared above were tested using a computer-controlled Keithley 2400 testing system, and the operating voltage and current efficiency were calculated. The device lifetime under dark conditions was obtained using a Fostar lifetime measurement system equipped with a power supply and photodiodes as detection units.

[0168] The devices of the above embodiments and comparative examples were produced and tested in the same batch. The ratios of the corresponding indicators of embodiments 31-60, comparative examples 1-4 and comparative example 1 were calculated to obtain the relative operating voltage, relative current efficiency and relative lifetime as shown in Table 3.

[0169] Table 3 Test results of Examples 31-60 and Comparative Examples 1-4

[0170]

[0171]

[0172] As shown in the table above, compared with Comparative Examples 1-4, the organic electroluminescent devices prepared using the compounds of this application exhibit significantly lower operating voltage and greatly improved current efficiency and lifetime. This is because the compounds of this application introduce aryl groups between the nitrogen atoms in the aryl alkyl and diamine systems, enhancing the overall conjugation of the molecules. This results in a more balanced electron and hole transport in the material molecules, thereby improving current efficiency. Simultaneously, the larger conjugated system enhances molecular stability, further improving device lifetime.

[0173] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. An organic compound, characterized in that, Its structural formula is shown in Formula I: ； In Equation I: L1 is selected from phenylene, biphenylene, naphthylene, and dibenzofuranylene; L2 is a phenylene or biphenylene; Ar1 is selected from phenyl, biphenyl, naphthyl, 9,9-dimethylfluorenyl or dibenzofuranyl; Ar2 is selected from phenyl, naphthyl, 9,9-dimethylfluorenyl, spirofluorenyl, dibenzofuranyl, or... Group; Ar3 is selected from phenyl, biphenyl, 9,9-dimethylfluorenyl or dibenzofuranyl; X is selected from O, S, or the following structures: ,in This is the connection site.

2. The organic compound according to claim 1, characterized in that, The structural formula of the organic compound is selected from the following group: ； Wherein, L2 is a phenylene or a biphenylene; The Ar2 is selected from phenyl, naphthyl, dibenzofuranyl, 9,9-dimethylfluorenyl, spirofluorenyl, or... Group; The Ar3 is selected from phenyl, biphenyl, 9,9-dimethylfluorenyl, or dibenzofuranyl.

3. The organic compound according to claim 2, characterized in that, The organic compounds are selected from the following group: 。 4. An organic layer, characterized in that, The organic layer is a hole transport layer, and the hole transport layer includes the organic compound according to any one of claims 1 to 3.

5. The use of the organic compound according to any one of claims 1 to 3 in the hole transport layer of an organic electroluminescent device.

6. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and the organic layer as described in claim 4.

7. A display or lighting device, characterized in that, Including the organic electroluminescent device as described in claim 6.

Images