Organic compound, and blue light emitting layer, organic light emitting device and device comprising same

Abstract

The invention relates to the technical field of organic electroluminescent doping materials, in particular to an organic compound, a blue light-emitting layer containing the organic compound, an organic light-emitting device and a device. The compound has a structure as shown in a formula I, wherein Ar1 and Ar2 in the formula I are respectively and independently selected from substituted or unsubstituted arylene of C6-C30 and substituted or unsubstituted heteroarylene of C5-C30, and are in ring combination with adjacent atoms; ar3, Ar4 and Ar5 are respectively and independently selected from a substituted or unsubstituted arylene group of C6 to C30, a substituted or unsubstituted heteroarylene group of C5 to C30, a substituted or unsubstituted aryl group of C6 to C30, and a substituted or unsubstituted heteroaryl group of C10 to C30; and at least one of Ar1-Ar5 contains a structural formula II. The organic compound provided by the invention can reduce the working voltage of the organic light-emitting device, improve the light-emitting efficiency of the device and prolong the relative life of the device.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent doped materials, specifically to an organic compound and a blue light-emitting layer containing it, organic light-emitting devices and apparatuses. Background Technology

[0002] In the OLED industry chain, organic light-emitting materials are the key technologies that determine display performance. In common organic electroluminescent devices, the light-emitting layer material is usually composed of a blend of light-emitting host material and doped guest material. The optimization of traditional blue light materials often faces a triangular contradiction between efficiency, voltage and lifetime. When improving efficiency, lifetime must be sacrificed, and when reducing voltage, stability will decrease.

[0003] Therefore, providing an organic light-emitting device that can reduce the operating voltage while improving the luminous efficiency and relative lifetime is the main technical problem that needs to be solved. Summary of the Invention

[0004] This invention provides an organic compound that aims to reduce the operating voltage of organic light-emitting devices while improving the luminous efficiency and relative lifespan of the devices.

[0005] This application provides an organic compound having the structure shown in Formula I: Equation I In Formula I, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C30 arylene groups and substituted or unsubstituted C5-C30 heteroarylene groups, and are cyclic with adjacent atoms; Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C5-C30 heteroaryl groups, substituted or unsubstituted C6-C30 aryl groups, and substituted or unsubstituted C10-C30 heteroaryl groups. Furthermore, at least one of Ar1-Ar5 contains structural formula II: Formula II.

[0006] The present invention provides a blue luminescent layer comprising the aforementioned organic compound.

[0007] The present invention provides an organic electroluminescent device, wherein the organic electroluminescent device includes the aforementioned blue light-emitting layer.

[0008] The present invention provides a display or lighting device comprising the aforementioned organic electroluminescent device.

[0009] Compared with the prior art, the technical solution of this application has the following beneficial effects: In this application, the inventors unexpectedly discovered during experiments that organic compounds containing heterofluorenoxy groups and boron-nitrogen (B-N) heterocyclic structures can reduce the operating voltage of organic light-emitting devices while improving their luminous efficiency and relative lifetime. This may reduce energy loss in electron transport, improve electron-hole recombination efficiency, and thus increase relative luminous efficiency. Furthermore, after the heterofluorenoxy groups and boron-nitrogen (B-N) heterocyclic structures are combined, the sterically hindered substituents can maintain appropriate intermolecular distances, ensuring unobstructed electron transport channels and improving device stability and lifetime. Moreover, during device operation, the stability of electron transport and luminescence processes is maintained, thereby improving relative lifetime and luminous efficiency. Detailed Implementation

[0010] The following describes in detail the embodiments of the organic compounds and preparation methods, blue light-emitting layers, and organic light-emitting devices and apparatuses provided by the present invention. The following description is intended to explain the present invention and is not intended to limit the scope of the invention in any way.

[0011] This invention provides an organic compound that aims to reduce the operating voltage of organic light-emitting devices while improving the luminous efficiency and relative lifespan of the devices.

[0012] The following is an explanation of some terms used in this application: Alkyl: Unless otherwise specified, alkyl groups can be straight-chain or branched, including but 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. The above description of alkyl groups can also be used for alkyl groups in aralkyl, alkylgermanium, aralkylamine, alkylaryl, and alkylamine groups.

[0013] Aryl: Unless otherwise specified, aryl can be monocyclic or polycyclic. In some embodiments, aryl can be monocyclic or polycyclic, including but not limited to phenyl, tert-butylphenyl, biphenyl, terphenyl, anthracene, naphthyl, phenanthrene, spirofluorene, triphenylene, and fluorene; the fluorene group can be substituted, such as 9,9-dimethylfluorene or 9,9-diphenylfluorene. The above description of aryl can also be applied to arylene groups, the difference being that arylene groups are divalent.

[0014] Heteroaryl: Unless otherwise specified, heteroaryl can refer to a group containing one or more of B, N, O, P, S, Si, and Se as a heteroatom; said heteroaryl includes, but is not limited to, pyrrole, pyridinyl, pyridazinyl, pyrimidinyl, thiophene, furanyl, imidazolyl, azole, pyrazolyl, isozolyl, thiazolyl, dibenzofuranyl, dibenzothiophene, naphthobenzothiophene, triphenylphosphine oxide, triphenylborane, oxafluorenyl, etc. The above description of heteroaryl can also be applied to heteroaryl derivatives, the difference being that heteroaryl derivatives are divalent.

[0015] Amine group: Unless otherwise specified, amine group may refer to any one of substituted or unsubstituted primary amine, substituted or unsubstituted secondary amine, or substituted or unsubstituted tertiary amine, including but not limited to substituted or unsubstituted diarylamine, substituted or unsubstituted diheteroarylamine, or substituted or unsubstituted arylheteroarylamine.

[0016] The term "substituted or unsubstituted" refers to the substitution of a hydrogen atom in a functional group by another atom or functional group (i.e., a substituent), for example, by one or more of the following substituents: deuterium, amino, alkoxy, alkylthio, aryloxyboronyl, straight-chain or branched alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkylaryl, alkylamine, aralkylamine, heteroarylamine, arylamine, heterocyclic; or by two or more combinations of substituents from the examples above, such as biphenyl or terphenyl.

[0017] A first aspect of the present invention provides an organic compound having a structure as shown in Formula I: Equation I In Formula I, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C30 arylene groups and substituted or unsubstituted C5-C30 heteroarylene groups, and are cyclic with adjacent atoms; Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C5-C30 heteroaryl groups, substituted or unsubstituted C6-C30 aryl groups, and substituted or unsubstituted C10-C30 heteroaryl groups. Furthermore, at least one of Ar1-Ar5 contains structural formula II: Formula II.

[0018] In this application, the inventors unexpectedly discovered during experiments that organic compounds containing heterofluorenoxy groups and boron nitrogen (BN) heterocyclic structures can reduce the operating voltage of organic light-emitting devices while improving the luminous efficiency and relative lifetime. A possible reason is that the BN bond has certain electron-deficient characteristics, which can regulate the molecular electron cloud density distribution. After combining with the heterofluorenoxy group, it expands the molecular conjugated system, increasing the degree of electron delocalization. A high degree of electron delocalization helps reduce the resistance to electron transport between molecules, thereby reducing the relative voltage of the device. In organic electroluminescent devices, reduced energy loss during electron transport improves electron-hole recombination efficiency, thus increasing the relative luminous efficiency. Furthermore, the combination of the heterofluorenoxy group and the boron nitrogen (BN) heterocyclic structure allows the sterically hindered substituents to maintain appropriate intermolecular distances, ensuring unobstructed electron transport channels and improving device stability and lifetime. Moreover, during device operation, it maintains the stability of electron transport and luminescence processes, thereby improving relative lifetime and luminous efficiency.

[0019] In some embodiments, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C29 arylene groups or substituted or unsubstituted C6-C29 heteroarylene groups, and are cyclically fused with adjacent atoms; further, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C8-C24 arylene groups or substituted or unsubstituted C8-C24 heteroarylene groups, and are cyclically fused with adjacent atoms; further, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C10-C18 arylene groups or substituted or unsubstituted C10-C18 heteroarylene groups, and are cyclically fused with adjacent atoms.

[0020] In some embodiments, Ar1 and Ar2 are each independently selected from any one or a combination of substituted or unsubstituted phenylene, biphenylene, naphthylene, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, dibenzofuranyl, triphenylene, 9,9-dimethylfluorenel, 9,9-diphenylfluorenel, and 9,9-dimethylhexyfluoroxy.

[0021] In some embodiments, Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C6-C29 arylene, substituted or unsubstituted C5-C29 heteroarylene, substituted or unsubstituted C6-C29 aryl, and substituted or unsubstituted C10-C29 heteroarylene; Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C8-C24 arylene, substituted or unsubstituted C8-C24 aryl, and substituted or unsubstituted C8-C24 heteroarylene; Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C10-C20 arylene, substituted or unsubstituted C10-C20 heteroarylene, substituted or unsubstituted C10-C20 aryl, and substituted or unsubstituted C10-C20 heteroarylene.

[0022] In some embodiments, Ar3, Ar4, and Ar5 are each independently selected from any one or a combination of substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthrene, fluorenyl, spirofluorenyl, carbazolyl, diphenylthiophene, dibenzofuranyl, triphenylene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, and 9,9-dimethylhexylfluorenoxy.

[0023] In some embodiments, the substituents in the substituted or unsubstituted group are selected from C1-C10 straight-chain or branched alkyl or cycloalkyl groups, C3-C30 aryl groups, C6-C30 heteroaryl groups, and C6-C30 amino groups; optionally, any hydrogen atom in the aforementioned substituents can be substituted with deuterium; further, the alkyl group is selected from any one of n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, and sec-butyl; further, the aryl group... The group is selected from any one of phenyl, tert-butylphenyl, biphenyl, terphenyl, anthracene, naphthyl, phenanthrene, spirofluorenyl, triphenylene, and fluorenyl; further, the heteroaryl group is selected from any one of pyrroleyl, pyridinyl, pyridinyl, pyrimidinyl, thiopheneyl, furanyl, imidazolyl, dibenzofuranyl, dibenzothiopheneyl, naphthobenzothiopheneyl, and oxafluorenyl; the amino group is selected from any one or a combination of diarylamino, diheteroarylamino, or arylheteroarylamino.

[0024] In some embodiments, the substituents in the substituted or unsubstituted form are selected from any one or a combination of the following structures: , , , , , , , , .

[0025] In some embodiments, the organic compound is selected from the group consisting of:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035] ; Ar1 and Ar2 are each independently selected from any one or more combinations of phenylene, substituted phenylene, biphenylene, naphthylene, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, substituted diphenylthiophene, dibenzofuranyl, trimyne, 9,9-dimethylfluorene, and 9,9-diphenylfluorene; Ar5 is selected from any one or more combinations of phenyl, tert-butylphenyl, biphenyl, naphthyl, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, dibenzofuranyl, trimyne, 9,9-dimethylfluorene, 9,9-diphenylfluorene, and 9,9-dimethylhexafluorenoxy; and the organic compound contains structural formula II; Preferably, Ar1 is selected from any one or a combination of the following groups:

[0036] Preferably, Ar2 is selected from any one or a combination of the following groups:

[0037] Preferably, A5 is selected from any one or a combination of tert-butylphenyl, 9,9-dimethylhexyloxy, and phenyl.

[0038] In some preferred embodiments of the present invention, the organic compound is selected from any of the following chemical structures:

[0039]

[0040]

[0041]

[0042] This application also provides a blue luminescent layer comprising the aforementioned organic compound.

[0043] This application also provides an organic electroluminescent device, which includes the blue light-emitting layer.

[0044] This application also provides a display or lighting device that includes the aforementioned organic electroluminescent device.

[0045] In some specific embodiments, the organic electroluminescent device includes a first electrode, a second electrode, and an organic layer. As an example, the first electrode is an anode, and the second electrode is a cathode, which 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 includes a blue emitting layer and at least one of a hole injection layer, a hole transport layer, an electron blocking layer, and an electron transport layer.

[0046] In some specific embodiments, the structure of the organic electroluminescent device may be selected from one of the following: (1) An organic electroluminescent device includes an anode, a hole injection layer, a first hole transport layer, an electron blocking layer, a blue light-emitting layer, a first electron transport layer, a first electron injection layer, and a cathode stacked in sequence, that is, anode / hole injection layer / first hole transport layer / blue light-emitting layer / first electron transport layer / cathode. The device structure will be expressed in this simplified way below.

[0047] (2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode.

[0048] (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.

[0049] (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.

[0050] (5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light emission layer / first electron transport layer / second electron transport layer / multilayer cathode.

[0051] (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.

[0052] (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.

[0053] (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.

[0054] (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.

[0055] (10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode.

[0056] (11) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0057] (12) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / cathode.

[0058] (13) Anode / hole injection layer / first hole transport layer / electron blocking layer / blue light emitting layer / first electron transport layer / first electron injection layer / cathode.

[0059] 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 an organic coating layer on the cathode side, as shown in the following structure: 1) Anode / hole injection layer / first hole transport layer / blue light-emitting layer / first electron transport layer / cathode / organic capping layer.

[0060] 2) Anode / hole injection layer / second hole transport layer / first hole transport layer / blue light-emitting layer / first electron transport layer / cathode / organic capping layer.

[0061] 3) Anode / hole injection layer / second hole transport layer / first hole transport layer / blue light-emitting layer / first electron transport layer / second electron transport layer / cathode / organic capping layer.

[0062] 4) Anode / hole injection layer / second hole transport layer / first hole transport layer / blue light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode / organic capping layer.

[0063] 5) Anode / hole injection layer / second hole transport layer / first hole transport layer / blue light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode / organic capping layer.

[0064] 6) Anode / hole injection layer / first hole transport layer / first blue light-emitting layer / carrier generation layer / first hole transport layer / second blue light-emitting layer / first electron transport layer / cathode / organic capping layer.

[0065] 7) Anode / hole injection layer / first hole transport layer / first blue light-emitting layer / carrier generation layer / first hole transport layer / second blue light-emitting layer / first electron transport layer / second electron transport layer / cathode / organic capping layer.

[0066] 8) Anode / hole injection layer / second hole transport layer / first hole transport layer / first blue light-emitting layer / carrier generation layer / first hole transport layer / second blue light-emitting layer / first electron transport layer / cathode / organic capping layer.

[0067] 9) Anode / Hole Injection Layer / Second Hole Transport Layer / First Hole Transport Layer / First Blue Emissive Layer / Carrier Generation Layer / First Hole Transport Layer / Second Blue Emissive Layer / First Electron Transport Layer / Second Electron Transport Layer / Cathode / Organic Covering Layer.

[0068] 10) Anode / Hole Injection Layer / Hole Transport Layer / Electron Blocking Layer / Blue Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode / Organic Capping Layer. (Device Structure of Embodiments in this Application) 11) Anode / hole injection layer / first hole transport layer / second hole transport layer / blue light-emitting layer / hole blocking layer / electron transport layer / cathode / organic capping layer.

[0069] 12) Anode / hole injection layer / hole transport layer / electron blocking layer / blue light emitting layer / electron transport layer / cathode / organic capping layer.

[0070] 13) Anode / hole injection layer / hole transport layer / electron blocking layer / blue light emitting layer / hole blocking layer / electron transport layer / cathode / organic capping layer.

[0071] The following describes some specific functional layers in the organic electroluminescent device.

[0072] Substrate: 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.

[0073] anode: Organic electroluminescent devices typically require the anode to have good conductivity, a smooth surface, and be resistant to cracking. They also have certain requirements for the work function, mainly to match the hole injection layer and achieve the hole injection effect.

[0074] 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 100 nm to 180 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.

[0075] When using a bottom-emitting method (light emission from the cathode side), 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.

[0076] The anode can be made by forming a thin film from the electrode material using methods such as vapor deposition, sputtering, or coating.

[0077] Hole injection layer: 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.

[0078] P-type materials can be metal oxides, such as molybdenum oxide, vanadium oxide, tungsten oxide, etc.; they can also be organic compounds, such as 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4-TCNQ, CAS No. 29261-33-4), 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 dimethane (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 used in conjunction with the P-type material can be selected from the material of the first hole transport layer, and can be the same as or different from the material of the first hole transport layer.

[0079] First hole transport layer: The thickness of the first 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.

[0080] Second hole transport layer: The thickness of the second hole transport layer is typically 3nm to 220nm. When there is no first hole transport layer, the thickness of the second hole transport layer is typically 40nm to 150nm; when there is a first hole transport layer, the thickness of the second 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. Taking a top-emitting device as an example, the formula for the microcavity is as follows:

[0081] 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.

[0082] 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 first hole transport layer, the thickness of the second hole transport layer is generally 160nm~220nm; with a first hole transport layer, the thickness is generally 8nm~120nm. For green light, without a first hole transport layer, the thickness of the second hole transport layer is generally 100nm~180nm; with a first hole transport layer, the thickness is generally 30nm~70nm. For blue light, without a first hole transport layer, the thickness of the second hole transport layer is generally 80nm~130nm; with a first hole transport layer, the thickness is generally 3nm~30nm. Different colors will have different optimal "microcavity adjustment thicknesses".

[0083] Electron blocking layer: 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, thereby improving the luminous efficiency of the device. It commonly employs aryl amine compounds, such as monoaryl amines or polyaryl amines.

[0084] Blue glowing layer: The material of the blue 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 emitting layer is 1% to 20%, and the thickness of the blue emitting layer is 3-30 nm. The guest dopant material is the aforementioned organic compound, and the film thickness ratio formed by the host material and the organic compound is (45-49.5):1.

[0085] 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 phosphorescent blue emission color has 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. As the main light-emitting material, one or two main light-emitting materials can be selected. Polycyclic aromatic hydrocarbons containing furan rings are often used as the main light-emitting materials.

[0086] Cavity blocking layer: To enhance the balance between hole and electron concentrations, a hole blocking layer is inserted to balance carrier concentration and prevent exciton quenching. Typically, the hole blocking layer is located between the emitting layer and the electron transport layer. The hole blocking layer material must meet conditions such as high stability, good film-forming properties, and a sufficiently high highest molecular occupied orbital (HOO). Polycyclic aromatic hydrocarbons containing furan rings are commonly used.

[0087] First electron transport layer: 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 of other metals or metal compounds. It can include mixtures of organic electron transport materials and metal compounds, or mixtures of organic electron transport materials and metals.

[0088] When organic electron transport materials are mixed with metal compound materials, for example, with alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and more specifically, with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc., the mass ratio of the organic electron transport material can be 20%~80%, 20%~40%, 40%~60%, or 60%~80%, etc. The organic electron transport materials commonly used are polyaryl amine compounds.

[0089] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, rare earth metals, or more specifically, lithium metals, magnesium metals, calcium metals, ytterbium metals, samarium metals, etc., the mass ratio of organic electron transport materials can be 80%~99%, 80%~89%, 89%~99%, 80%~85%, 85%~90%, 90%~95%, or 95%~99%, etc.

[0090] Second electron transport layer: The thickness of the second electron transport layer is generally 10nm~40nm. The material of the second electron transport layer can include a mixture of organic electron transport materials and metal compounds, or a mixture of organic electron transport materials and metals.

[0091] 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.

[0092] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, rare earth metals, or more specifically, lithium metals, magnesium metals, calcium metals, ytterbium metals, samarium metals, etc., the mass ratio of organic electron transport materials can be 80%~99%, 80%~89%, 89%~99%, 80%~85%, 85%~90%, 90%~95%, or 95%~99%, etc.

[0093] Electron injection layer: The material of the electron injection layer can be selected from alkali metals, alkaline earth metals, rare earth metals, or their inorganic or coordination compounds.

[0094] cathode: 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.

[0095] 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.

[0096] Organic coating: The refractive index n and absorption coefficient of a single-layer organic coating must meet the following conditions: The refractive index n(450~650nm) is greater than 1.8 in the wavelength range of 450~650nm, and the extinction coefficient in the wavelength range 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.

[0097] Materials that can meet the requirements of the organic coating layer for refractive index n can further achieve high luminous efficiency of the device, while the light output efficiency and viewing angle of red, green and blue light are more balanced.

[0098] In some specific embodiments, the thickness of the organic coating layer is 50nm~90nm, for example, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 65nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0099] The organic capping layer is formed after the semi-transparent cathode of the OLED display panel is away from the substrate, and the stack formed by the capping layer and the semi-transparent cathode has a light transmittance of ≥65% for light between 450nm and 650nm, such as 68%, 69%, 73%, 77%, 79%, 83%, 88%, 93%, etc.

[0100] When using two capping layers, the refractive index n and absorption coefficient need to satisfy the following conditions: The organic capping layer (first capping layer) near the cathode has a refractive index n450~650nm<1.8 between wavelengths of 450~650nm, and an extinction coefficient between wavelengths of 450~650nm is less than 0.1; the maximum coefficient between wavelengths of 250nm~350nm is greater than 0.3, and the optimal value is greater than 0.6.

[0101] The organic capping layer (second capping layer) away from the cathode has a refractive index n450~650nm>1.8 between wavelengths of 450~650nm, and an extinction coefficient between wavelengths of 450~650nm below 0.1; and an extinction coefficient greater than 0.1 at 380nm, preferably greater than 0.2.

[0102] 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. 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.

[0103] The total thickness of the double-layer capping layer is 50nm~90nm, for example: 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, 88nm, 90nm, etc.

[0104] The thickness of the organic capping layer (first capping layer) near the cathode side is 5nm~40nm, for example: 5nm, 7nm, 10nm, 12nm, 15nm, 18nm, 20nm, 22nm, 25nm, 27nm, 30nm, 32nm, 34nm, 36nm, 38nm, 40nm, etc.

[0105] The thickness of the organic capping layer (second capping layer) away from the cathode side is 35nm~85nm, for example: 35nm, 40nm, 43nm, 45nm, 48nm, 50nm, 55nm, 57nm, 59nm, 62nm, 64nm, 67nm, 68nm, 70nm, 75nm, 77nm, 79nm, 80nm, 82nm, 85nm, etc.

[0106] This application also provides a display or lighting device that includes the above-described organic electroluminescent device.

[0107] Synthesis Example: The specific preparation methods of the above-mentioned organic compounds of this application will be described in detail below using multiple synthetic examples. However, the preparation methods of this invention are not limited to these multiple synthetic examples. Those skilled in the art can make any modifications, equivalent substitutions, improvements, etc. on the basis of these examples without departing from the principles of this invention, and extend the method to the scope of the technical solutions claimed in the claims of this invention.

[0108] 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.

[0109] Measurement instruments and methods Mass spectrometry and nuclear magnetic resonance In this application, mass spectrometry was performed using a Waters Corporation single quadrupole mass spectrometer, and nuclear magnetic resonance was performed using a 400MHz nuclear magnetic resonance spectrometer (manufactured by Bruker GmbH, Germany).

[0110] [Performance Measurement] The operating voltage and luminous efficiency of the organic electroluminescent device were calculated using a computer-controlled Keithley 2400 testing system. The lifetime of the organic electroluminescent device under dark conditions was obtained using a Fostar lifetime measurement system equipped with a power supply and photodiodes as detection units.

[0111] [Raw Materials and Reagents] The initial raw materials XA, XB, potassium phosphate, and tetrahydrofuran were purchased from Shanghai Titan Technology Co., Ltd., and the XPhos Pd G3 catalyst was purchased from Shaanxi Ruike New Materials Co., Ltd. 1H NMR data were determined using a 400MHz nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany); HPLC data were determined using a Waters Corporation UPLC (ultra-high performance liquid chromatography). LC-MS (liquid chromatography-mass spectrometry) was performed on a Waters Corporation UPLC+SQD2 instrument.

[0112] Example 1 The synthesis of organic compound 1 follows the reaction process shown below:

[0113] The preparation method of organic compound 1 includes the following steps: Under an argon atmosphere, 1-A (101 g, 101 mmol), reactant 1-B (21.3 g, 100 mmol), XPhos Pd G3 (787 mg), 1.5 M potassium phosphate (50 mL, 300 mmol), and tetrahydrofuran (1000 mL) were added sequentially to the reaction vessel. The mixture was refluxed and stirred for 12 hours. After cooling to room temperature, water (800 mL) was added, resulting in the precipitation of a large amount of solid. The solid was filtered, and the filter cake was washed three times with water and dried under vacuum to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluting with a mixture of ethyl acetate and hexane) to give organic compound 1 (75.8 g, yield 58%, LC-MS: M / Z 1131.63 (M+)).

[0114] Following the preparation method of organic compound 1, the organic compounds listed in Table 1 were synthesized. For each organic compound X, the main raw materials 1-A and 1-B involved in the above preparation method are represented as XA and XB, respectively. The main raw materials used, yields, and mass spectrometry characterization data are shown in Table 1.

[0115] Table 1

[0116] The NMR data of organic compounds 1-10 involved in the synthesis examples are shown in Table 2: Device Examples: The compounds involved in this invention can be used as blue light-emitting layer materials for organic electroluminescent devices. The specific device fabrication method and test results are given below.

[0117] Fabrication of organic electroluminescent devices Device Example 1 An organic electroluminescent device was fabricated using a structure consisting of anode / hole injection layer / hole transport layer / electron blocking layer / blue emitting layer / electron transport layer / electron injection layer / cathode / organic capping layer, with the following fabrication steps: S1. A transparent ITO film (150 nm thick) is formed on a glass substrate by magnetron sputtering to obtain the first electrode as the anode; S2. Deposit compound F4 onto the surface of the anode. TCNQ forms a hole injection layer (10nm thick). S3. Vacuum evaporation of compound NPB onto the hole injection layer to form a hole transport layer (thickness of 110 nm). S3. Evaporate compound EB-01 on the hole transport layer to form an electron blocking layer (10 nm thick). S4. Using compound BH as the main body on the electron blocking layer, organic compound 1 provided in Example 1 is simultaneously doped with the film thickness ratio of 98:2 to form a blue light-emitting layer (thickness of 10 nm). S5. Apply the polyarylamine compound ET onto the blue luminescent layer. An electron transport layer (30 nm thick) is formed by vapor deposition of 01 and LiQ at a film thickness ratio of 1:1. S6. Yb is deposited on the electron transport layer to form an electron injection layer (15 angstroms thick). S7. Magnesium and silver are vacuum-deposited onto the electron injection layer at a film thickness ratio of 1:9 to form a cathode (thickness of 11 nm). S8. Depositing compound CP on the cathode 1. Form an organic capping layer (65 nm thick) to obtain an organic electroluminescent device.

[0118] The compound F4 TCNQ, NPB, EB-01, BH, ET 01. LiQ and CP The chemical structure of 1 is shown in Table 3.

[0119] Table 3

[0120] Device Example 2 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 2 provided in embodiment 2 is doped in S4.

[0121] Device Example 3 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 3 provided in embodiment 3 is doped in S4.

[0122] Device Example 4 This embodiment provides an organic electroluminescent device, which is prepared by the same method as in device embodiment 1, except that S4 is doped with the organic compound 4 provided in embodiment 4.

[0123] Device Example 5 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 5 provided in embodiment 5 is doped in S4.

[0124] Device Example 6 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 6 provided in embodiment 6 is doped in S4.

[0125] Device Example 7 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 7 provided in embodiment 7 is doped in S4.

[0126] Device Example 8 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 8 provided in embodiment 8 is doped in S4.

[0127] Device Example 9 This embodiment provides an organic electroluminescent device, which is prepared in the same way as in device embodiment 1, except that organic compound 9 provided in embodiment 9 is doped in S4.

[0128] Device Example 10 This embodiment provides an organic electroluminescent device, which is prepared by the same method as in device embodiment 1, except that organic compound 10 provided in embodiment 10 is doped in S4.

[0129] Device Comparison Example 1 This comparative example provides an organic electroluminescent device, which is prepared in the same way as in device example 1, except that compound BD-1 is doped in S4. The chemical structure of compound BD-1 is shown in Table 4.

[0130] Device Comparison Example 2 This comparative example provides an organic electroluminescent device, which is prepared using the same method as in Device Example 1, except that compound BD-2 is doped in S4. The chemical structure of compound BD-2 is shown in Table 4. Table 4

[0131] The organic electroluminescent devices provided in Device Examples 1-10 and the organic electroluminescent devices provided in Device Comparative Examples 1-2 were produced and tested in the same batch. The operating voltage, luminous efficiency and lifetime of the organic electroluminescent device provided in Device Comparative Example 1 were all recorded as 1. The ratios of the corresponding indicators of the organic electroluminescent devices provided in Device Examples 1-10, the organic electroluminescent devices provided in Device Comparative Example 2 and Device Comparative Example 1 were calculated respectively. The test results are shown in Table 5.

[0132] Table 5

[0133] As can be seen from the test results in Table 5, the organic electroluminescent devices provided in Device Examples 1-10 have lower operating voltage, higher luminous efficiency, and longer lifespan than the organic electroluminescent devices provided in Device Comparative Examples 1 and 2. The organic compounds 1-10 provided in Examples 1-10, as guest doping materials for the blue luminescent layer, can reduce the operating voltage of the organic luminescent device while improving the luminous efficiency and relative lifespan of the device.

[0134] The organic compounds 1-10 provided in Examples 1-10 contain heterocyclic structures of fluorenoxy and boron nitrogen (B-N), and the organic electroluminescent devices of Examples 1-10 have a relative voltage of less than 1, a relative luminous efficiency of more than 1.3, and a relative lifetime of more than 1.35.

[0135] Comparative Example 1 used compound BD-1, while Examples 1-10 used the organic compounds provided in Examples 1-10. Compared with organic compounds 1-10, compound BD-1 contains heterofluorenoxy groups, but compound BD-1 does not contain boron-nitrogen (BN) heterocyclic structures. The organic electroluminescent device obtained in Comparative Example 1 has a high voltage, but its relative luminous efficiency and relative lifetime are lower than those of the organic electroluminescent devices provided in Examples 1-10. The possible reason is that the overall conjugated system of compound BD-1 is relatively regular, mainly connecting different aromatic rings through nitrogen atoms. The electron cloud distribution is relatively concentrated in the aromatic ring system, the spatial structure is relatively compact, and the intramolecular interaction is strong, but it is not conducive to electron-hole recombination, resulting in lower luminous efficiency.

[0136] Comparative Example 2 used compound BD-2, while Examples 1-10 used the organic compounds provided in Examples 1-10. Compared with organic compounds 1-10, compound BD-2 contains a boron nitrogen (BN) structure, but compound BD-2 does not contain a heterofluorenyl group. The relative voltage of the organic electroluminescent device obtained in Comparative Example 2 is higher than that of the organic electroluminescent devices provided in Examples 1-10, and the relative luminous efficiency and relative lifetime are lower than those of the organic electroluminescent devices provided in Examples 1-10. The possible reason is that the B-N structure in compound BD-2 has certain electron-deficient characteristics. The sulfur heterocycle changes the electron cloud distribution and molecular polarity, which expands the conjugated system and makes the electron cloud distribution more dispersed, increases the intermolecular distance, and reduces the intermolecular π-π stacking, which is beneficial to electron transport, but affects the intermolecular interaction and the luminous efficiency of the device.

Claims

1. An organic compound, characterized in that, The compound has the structure shown in Formula I: Equation I In Formula I, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C30 arylene groups and substituted or unsubstituted C5-C30 heteroarylene groups, and are cyclic with adjacent atoms; Ar3, Ar4, and Ar5 are each independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C5-C30 heteroaryl groups, substituted or unsubstituted C6-C30 aryl groups, and substituted or unsubstituted C10-C30 heteroaryl groups. Furthermore, at least one of Ar1-Ar5 contains structural formula II: Formula II.

2. The organic compound according to claim 1, characterized in that, Ar1 and Ar2 are each independently selected from any one or a combination of substituted or unsubstituted phenylene, biphenylene, naphthylene, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, dibenzofuranyl, triphenylene, 9,9-dimethylfluorenel, 9,9-diphenylfluorenel, and 9,9-dimethylhexylfluoreneoxy.

3. The organic compound according to claim 1, characterized in that, Ar3, Ar4, and Ar5 are each independently selected from any one or a combination of substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthryl, fluorenyl, spirofluorenyl, carbazolyl, diphenylthiophene, dibenzofuranyl, triphenylene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, and 9,9-dimethylhexylfluorenoxy.

4. The organic compound according to any one of claims 1 to 3, characterized in that, The substituents in the substituted or unsubstituted group are selected from C1-C10 straight-chain or branched alkyl or cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, and C6-C30 amino groups; optionally, any hydrogen atom in the aforementioned substituents may be substituted with deuterium.

5. The organic compound according to claim 4, characterized in that, The substituents in the substituted or unsubstituted form are selected from any one or a combination of the following structures: 、 、 、 、 、 、 、 。 6. The organic compound according to claim 1, characterized in that, The organic compounds are selected from the following group: ； Wherein, Ar1 and Ar2 are each independently selected from any one or more combinations of phenylene, substituted phenylene, biphenylene, naphthylene, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, substituted diphenylthiophene, dibenzofuranyl, trimyne, 9,9-dimethylfluorene, and 9,9-diphenylfluorene; Ar5 is selected from any one or more combinations of phenyl, tert-butylphenyl, biphenyl, naphthyl, phenanthrene, fluorene, spirofluorene, carbazolyl, diphenylthiophene, dibenzofuranyl, trimyne, 9,9-dimethylfluorene, 9,9-diphenylfluorene, and 9,9-dimethylhexafluoreneoxy; and the organic compound contains structural formula II; preferably, Ar1 is selected from any one or a combination of the following groups: ； Preferably, Ar2 is selected from any one or a combination of the following groups: ； Preferably, A5 is selected from any one or a combination of tert-butylphenyl, 9,9-dimethylhexyloxy, and phenyl.

7. The organic compound according to claim 1, characterized in that, The organic compound includes any one of the following structural formulas: 。 8. A blue luminescent layer, characterized in that, The blue luminescent layer comprises an organic compound as described in any one of claims 1-7.

9. An organic electroluminescent device, characterized in that, Includes the blue luminescent layer as described in claim 8.

10. A display or lighting device, characterized in that, Including the organic electroluminescent device as described in claim 9.

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