Organic electroluminescence element

Abstract

To provide an organic electroluminescent device that can significantly improve the overall performance of the device, particularly the service life of the device.SOLUTION: An organic electroluminescent device includes an anode, a cathode, and an organic layer which is disposed between the anode and the cathode and includes a first organic layer and a second organic layer. The first organic layer contains a first organic material and a first p-type dopant, and the second organic layer contains a second organic material and a second p-type dopant. The first organic layer comes into contact with the second organic layer. The p-type dopant has a structure represented by Formula 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to an organic electroluminescent device. More specifically, the present application relates to an organic electroluminescent device having a specific organic layer containing a specific p-type dopant, with at least two layers in contact. The present application further relates to an electronic assembly including the organic electroluminescent device. [Background technology]

[0002] Organic electronic devices include, but are not limited to, organic light emitting diodes (OLEDs), organic field effect transistors (O-FETs), organic light emitting transistors (OLETs), organic photovoltaic cells (OPVs), dye-sensitized solar cells (DSSCs), organic photodetectors, organic photosensitive devices, organic field effect devices (OFQDs), light emitting electrochemical cells (LECs), organic laser diodes, and organic plasma light emitting devices.

[0003] Organic electroluminescent devices (OLEDs) are stacked with a cathode, an anode, and a series of organic layers between the cathode and the anode. By applying a voltage across the cathode and the anode of the device, electrical energy is converted into light, and the device has the advantages of a wide viewing angle, high contrast, and faster response time. In 1987, Tang and Van Slyke of Eastman Kodak reported an organic light-emitting device with an arylamine hole-transporting layer and a tris-8-hydroxyquinoline-aluminum layer as an electron-transporting layer and a light-emitting layer (Applied Physics Letters, 1987, 51(12):913-915). When a voltage is applied across the device, green light is emitted from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). OLEDs are self-luminous solid-state devices, offering enormous potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, make them suitable for special applications, such as manufacturing flexible displays or lighting on flexible substrates. OLEDs have the advantages of low cost, low power consumption, high brightness, wide viewing angle, thin thickness, etc., and have been widely applied in the fields of display and lighting after decades of development.

[0004] OLED devices are generally made up of multiple organic functional layers, including an emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and other functional layers. In the hole injection layer and the electron injection layer, holes and electrons are injected into the device from the anode terminal and the cathode terminal, respectively, and the two carriers then transfer to the emitting layer through the transport layer, where they combine to form excitons, which emit light as they fall from the excited state to the ground state. Among them, the electron blocking layer and the hole blocking layer are generally selectable layers.

[0005] Effective combination of electrons and holes is an important factor that affects the luminescence quantum efficiency of the device. Currently, there are three main ways to improve the carrier balance of OLED devices. One is to balance the carrier concentration by using suitable electron and hole injection materials. The second is to achieve the balance by changing the transport ability of the carrier transport material by using suitable electron and hole transport materials. The third is to achieve the carrier balance by adjusting the transport performance of the host material and / or the light-emitting material in the light-emitting layer. Most of the hole transport materials (HTM) in existing OLED devices are arylamine-based compounds, which have strong electron supplying ability and can achieve good hole conduction. Assuming that the concentrations of electrons and holes injected from the cathode and anode are the same, due to the difference in the performance of the organic materials themselves, the hole mobility in the OLED structure may be higher than the electron mobility, i.e., the hole concentration transported to the light-emitting layer is much larger than the electron concentration, resulting in an unbalanced carrier concentration and forming a hole-rich device. The imbalance of carriers is likely to cause carriers to accumulate at the film layer boundary and generate heat, which not only accelerates the aging of the device and reduces its service life, but also reduces the exciton complex probability and reduces the efficiency of the device. However, the carriers can be balanced by improving the electron injection and transport performance, but the types of organic materials that can be selected are relatively small.

[0006] In order to balance electrons and holes in OLED, the conventional method is usually to increase the thickness of the hole transport layer, so that the electrons and holes can be effectively combined in the light emitting layer within the same time, and do not cause hole accumulation.However, the increase in the thickness of the hole transport layer may bring about negative effects such as increased voltage, decreased efficiency, and even shortened service life.

[0007] Patent CN100373656C discloses an organic light-emitting display device with a combination of a hole injection layer and a first hole transport layer. The hole injection layer uses a fluorocarbon compound, and the first hole transport layer uses a p-type dopant. The hole injection layer promotes hole injection, and the first hole transport layer containing a p-type dopant promotes hole transport and conduction, thereby improving the service life of the device and stabilizing the voltage of the device. The patent introduces a p-type doped first hole transport layer to reduce the voltage. However, the patent discloses a device containing only one p-type doped organic layer, but not multiple p-type doped organic layers.

[0008] Patent CN109216565B discloses an organic electroluminescence device. Its hole injection layer is composed of a first doping layer and a second doping layer. The first doping layer is composed of a p-type dopant, and the material is selected from NPD-2 or NPD-9, and is used to inject a large amount of holes. The second doping layer contains a p-type dopant and a hole transport material, and adjusts the doping concentration to adjust the amount of hole injection, thereby adjusting the balance between electrons and holes to achieve the purpose of improving the service life of the device. The first doping layer in the application adopts an organic layer containing only a p-type dopant. That is, the patent discloses a device containing only one p-type doped organic layer, but does not disclose a device containing multiple p-type doped organic layers. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] CN100373656C [Patent Document 2] CN109216565B [Non-patent literature]

[0010] [Non-Patent Document 1] Applied Physics Letters, 1987, 51(12):913~915 Summary of the Invention [Problem to be solved by the invention]

[0011] In view of the above-mentioned problems, the present invention aims to provide a novel organic electroluminescent device, which comprises an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer comprises a first organic layer and a second organic layer in direct contact with each other, the second organic layer being located on the first organic layer, the first organic layer containing a first organic material and a first p-type dopant, the second organic layer containing a second organic material and a second p-type dopant, and the p-type dopant having a structure represented by Formula 1. The organic electroluminescent device containing a p-type dopant with a specific structure and having a specific device structure can significantly improve the overall performance of the device, especially the service life of the device. [Means for solving the problem]

[0012] According to one embodiment of the present invention, there is provided an organic electroluminescent device, comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer includes a first organic layer and a second organic layer; the first organic layer comprises a first organic material and a first p-type dopant; the second organic layer comprises a second organic material and a second p-type dopant; the first organic layer is in contact with a second organic layer, the second organic layer overlying the first organic layer; An organic electroluminescent device is disclosed, wherein the first p-type dopant and the second p-type dopant each independently have a structure represented by Formula 1: [ka] (n is an integer selected from 1 to 5, Ring A is the same or different at each occurrence and is selected from conjugated rings having 4 to 30 ring atoms; R3 represents mono-, poly- or no substitution; R1, R2 and R3 are the same or different at each occurrence and are selected from hydrogen, deuterium or a substituent; At least one R3 is selected from hydrogen, deuterium, or a substituent containing at least two atoms; Adjacent substituents R1, R2, and R3 may be bonded to form a ring.

[0013] According to an embodiment of the present invention, there is further disclosed an electronic assembly including the organic electroluminescent device according to the above-mentioned embodiments.

[0014] The present invention provides a novel organic electroluminescent device, comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer comprises a first organic layer and a second organic layer in direct contact with each other, the second organic layer being located on the first organic layer, the first organic layer containing a first organic material and a first p-type dopant, the second organic layer containing a second organic material and a second p-type dopant, and the p-type dopant having a structure represented by Formula 1. The organic electroluminescent device containing a p-type dopant with a specific structure and having a specific device structure can significantly improve the overall performance of the device, especially the service life of the device. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of an organic light-emitting device 100. FIG. [Diagram 2] 2 is a schematic diagram of an organic light-emitting device 200. FIG. [Diagram 3] 1 is a schematic diagram of an organic electroluminescence element 300. FIG. [Figure 4] FIG. 4 is a schematic diagram of a laminated organic electroluminescence element 400. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] OLEDs can be fabricated on various substrates, such as glass, plastic, and metal. FIG. 1 shows an organic light-emitting device 100 by way of example and without limitation. The drawings are not necessarily drawn to scale, and some layer structures may be omitted in the drawings as necessary. The device 100 may include a substrate 101, an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140 (optional layer), an emissive layer 150, a hole blocking layer 160 (optional layer), an electron transport layer 170, an electron injection layer 180, and a cathode 190. The device 100 may be fabricated by depositing the layers described in order. In some applications, the hole injection layer 120 and the hole transport layer 130 are collectively referred to as a hole transport layer, or a first hole transport layer, a second hole transport layer, but the two have a major difference in that the hole injection layer is usually in direct contact with the anode and has a smaller thickness than the hole transport layer. The properties, functions and exemplary materials of each layer are described in more detail in columns 6-10 of US Pat. No. 7,279,704 B2, the contents of which are incorporated herein in their entirety by reference.

[0017] There are many examples of each of these layers. Illustratively, in U.S. Patent Application Publication No. 5,844,363, which is incorporated herein by reference in its entirety, a flexible and transparent substrate-anode combination is disclosed. For example, in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety, an example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 1:50. An example of a host material is disclosed in U.S. Patent Application Publication No. 6,303,238 by Thompson et al., which is incorporated herein by reference in its entirety. For example, in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety, an example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1. Examples of cathodes are disclosed in U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, including composite cathodes having a thin metal layer, such as Mg:Ag, and a sputter-deposited transparent conductive ITO layer coated thereon. The principles and uses of blocking layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety. Protective layers are described in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety.

[0018] The above-mentioned split-layer structures are provided by way of non-limiting examples. The functions of the OLED can be realized by combining the various layers described above, or some layers can be omitted entirely. For example, the hole blocking layer is not a necessary layer and can be omitted in some structures. It may include other layers not explicitly described. Within each layer, a single material or a mixture of multiple materials can be used to achieve optimal performance. Any of the functional layers may include multiple sub-layers, for example, an emitting layer may have two layers of different emitting materials to achieve a desired emission spectrum.

[0019] In one embodiment, an OLED may be described as having an "organic layer" disposed between a cathode and an anode. The organic layer may include one or more layers.

[0020] An OLED also requires an encapsulation layer, and as shown in FIG. 2, an organic light-emitting device 200 is shown by way of example and not by way of limitation. The difference from FIG. 1 is that it may include an encapsulation layer 102 on the cathode 190 to prevent harmful substances from the outside, such as moisture and oxygen. Any material that can provide an encapsulation function, such as glass or an organic-inorganic mixed layer, may be used as the encapsulation layer. The encapsulation layer should be disposed directly or indirectly on the outside of the OLED element. A multi-layer thin-film encapsulation is described in U.S. Pat. No. US7968146B2, the entire contents of which are incorporated herein by reference.

[0021] Devices manufactured according to embodiments of the invention may be incorporated into a variety of consumer products having one or more electronic modules (or units) of the device, including, for example, flat panel displays, monitors, medical monitors, televisions, billboards, indoor or outdoor lighting and / or signaling lamps, heads-up displays, fully or partially transparent displays, flexible displays, smart phones, flat panel computers, flat panel mobile phones, wearable devices, smart watches, laptop computers, digital cameras, handheld video cameras, viewfinders, microdisplays, 3-D displays, in-vehicle displays, and tail lights.

[0022] The materials and structures described herein may also be used in the other organic electronic devices listed above.

[0023] Various OLED manufacturing methods are known. Small molecule OLEDs are generally manufactured by vacuum thermal evaporation. Polymer OLEDs are manufactured by solution processes, such as spin coating, inkjet printing, and nozzle printing. If the material can be dissolved or dispersed in a solvent, small molecule OLEDs can also be manufactured by solution processes. Each organic layer in the organic electroluminescent device according to the present application can be manufactured by deposition or solution processes. For example, the first organic layer and the second organic layer in the present application can be manufactured by deposition or solution processes as necessary.

[0024] In this specification, the energy levels of a compound (LUMO energy level: lowest unoccupied molecular orbital, HOMO energy level: highest occupied molecular orbital) are measured by cyclic voltammetry. For example, the compound HATCN measured by the test method of the present application [ka] The LUMO energy level of is -4.33 eV. In this specification, all "LUMO energy levels" and "HOMO energy levels" are expressed as negative values, and the smaller the numerical value (i.e., the larger the absolute value), the deeper the energy level. In this specification, a statement that an energy level is smaller than a certain value indicates that the energy level is numerically smaller than this value, i.e., has a more negative value. For example, the LUMO energy level of an organic material is -4.2 eV or less indicates that the LUMO energy level of the organic material is numerically -4.2 eV or more negative than -4.2 eV, i.e., the LUMO energy level of the organic material is deeper than 4.2 eV.

[0025] The term "doping ratio" refers to the percentage of one material of an organic layer to the total mass of the organic layer. For example, the doping ratio of the first p-type dopant in the first organic layer referred to in this application refers to the percentage of the first p-type dopant to the total mass of the first organic layer. When the first organic layer is composed of the first organic material and the first p-type dopant, the total mass of the first organic layer is the sum of the mass of the first organic material and the first p-type dopant.

[0026] In this application, the term "same" or "different" materials refers to, for example, "a first p-type dopant and a second p-type dopant are different" and "a first organic material and a second organic material are the same or different." In this context, "same" refers to two or more materials having the same chemical structure, or the difference between the two or more materials is only that some or all of the hydrogens in the chemical structure are replaced with deuterium. Conversely, "different" refers to the chemical structure of the organic materials used being different (i.e., the difference between the chemical structure formulas is not only that some or all of the hydrogens in the molecular formula are replaced with deuterium).

[0027] In the present application, the organic layers being "different" means that if the organic layers are layers containing only a single material, the organic layers contain different materials. If the organic layers are composite materials / layers containing at least two materials, at least one of the materials contained in the organic layers is different, or the composite materials / layers formed by the organic layers are different (the materials in the composite materials / layers are different and / or the doping rates are different). The organic layers being "same" means that the materials in the organic layers are the same and the doping rates are also the same.

[0028] As used herein, the term "p-type dopant" refers to a dopant that has oxidizing ability, has strong electron-withdrawing ability, and is an electron acceptor. In this specification, it refers to a molecular type p-type dopant.

[0029] As used herein, the "molecular p-type dopant" refers to an organic compound consisting of 6 or more atoms in a dopant molecule. Preferably, the number of atoms forming the dopant molecule is greater than 10. More preferably, the number of atoms forming the dopant molecule is greater than 20. Preferably, the molar mass of the "molecular p-type organic dopant" is 200 g / mol to 2000 g / mol. Preferably, it is 300 g / mol to 1800 g / mol. More preferably, it is 400 g / mol to 1500 g / mol.

[0030] As used herein, "top" means furthest from the anode and "bottom" means closest to the anode. When a second layer is described as being "on" a first layer, the first layer is relatively close to the anode. Conversely, when a second layer is described as being "on" a first layer, the second layer is relatively close to the anode. Other layers may be present between the first layer and the second layer, unless it is specified that the first layer is "in contact with" the second layer. Illustratively, the cathode may still be described as being "on" the anode, even if there are various organic layers between the cathode and the anode.

[0031] As used herein, an "emitting unit" is an organic material layer that emits light by applying a voltage or current. One "emitting unit" includes at least one emitting layer. The emitting layer further contains a host material and a light-emitting material. The "emitting unit" further includes at least one pair of hole and electron injection / transport layers, such as a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer and an electron injection layer.

[0032] As used herein, a "charge generation layer (CGL)" is a layer for providing electrons and holes between two light-emitting units, and is composed of an n-type charge generation layer and a p-type charge generation layer. The n-type charge generation layer contacts the electron transport layer or electron injection layer of one light-emitting unit, and the p-type charge generation layer usually contacts the hole injection layer or hole transport layer of the adjacent light-emitting unit and provides holes to the latter. The p-type charge generation layer may be composed of a single material p-type dopant, or may be a composite layer in which a hole transport material is doped with a p-type dopant.

[0033] Definitions of Substituent Terminology

[0034] Halogen or halide, as used herein, includes fluorine, chlorine, bromine and iodine.

[0035] As used herein, alkyl groups include straight and branched chain alkyl groups. The alkyl groups may be alkyl groups having 1 to 20 carbon atoms, preferably alkyl groups having 1 to 12 carbon atoms, and more preferably alkyl groups having 1 to 6 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, and 3-methylpentyl. Of these, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl and n-hexane are preferred. The alkyl group may be optionally substituted.

[0036] As used herein, the cycloalkyl group includes cyclic alkyl groups. The cycloalkyl group may be a cycloalkyl group having 3 to 20 ring carbon atoms, and is preferably a cycloalkyl group having 4 to 10 carbon atoms. Examples of the cycloalkyl group include cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl group, and 2-norbornyl group. Of these, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, and 4,4-dimethylcyclohexyl are preferred. The cycloalkyl group may be substituted.

[0037] As used herein, a heteroalkyl group is one in which one or more carbons in an alkyl chain are replaced with a heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, a phosphorus atom, a silicon atom, a germanium atom, and a boron atom. The heteroalkyl group may be a heteroalkyl group having 1 to 20 carbon atoms, preferably a heteroalkyl group having 1 to 10 carbon atoms, and more preferably a heteroalkyl group having 1 to 6 carbon atoms. Illustrative examples of heteroalkyl groups are methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermaniummethyl, trimethylgermaniumethyl, trimethylgermaniumisopropyl, dimethylethylgermaniummethyl, dimethylisopropylgermaniummethyl, tert-butyldimethylgermaniummethyl, triethylgermaniummethyl, triethylgermaniumethyl, triisopropylgermaniummethyl, triisopropylgermaniumethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, trimethylsilylisopropyl, triisopropylsilylmethyl, and triisopropyloylsilylethyl. Heteroalkyl groups may also be substituted.

[0038] As used herein, alkenyl groups include linear, branched and cyclic olefin groups. The linear alkenyl group may be an alkenyl group having 2 to 20 carbon atoms, and is preferably an alkenyl group having 2 to 10 carbon atoms. Examples of alkenyl groups include vinyl, propylene, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, styryl, 2,2-diphenylvinyl, 1,2-diphenylvinyl, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1-phenylallyl, 2-phenylallyl, 3-phenylallyl, 3,3-diphenylallyl, 1,2-dimethylallyl, 1-phenyl-1-butenyl, 3-phenyl-1-butenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl, cycloheptatrienyl, cyclooctenyl, cyclooctatetraenyl and norbornylalkenyl groups. The alkenyl group may be substituted.

[0039] As used herein, the term "alkynyl group" includes linear alkynyl groups. The alkynyl group may be an alkynyl group having 2 to 20 carbon atoms, and is preferably an alkynyl group having 2 to 10 carbon atoms. Examples of the alkynyl group include an ethynyl group, a propynyl group, a propargyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-pentynyl group, a 2-pentynyl group, a 3,3-dimethyl-1-butynyl group, a 3-ethyl-3-methyl-1-pentynyl group, a 3,3-diisopropyl-1-pentynyl group, a phenylethynyl group, and a phenylpropynyl group. Among these, an ethynyl group, a propynyl group, a propargyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-pentynyl group, and a phenylethynyl group are preferred. The alkynyl group may be substituted.

[0040] As used herein, aryl or aromatic groups contemplate non-condensed and condensed systems. The aryl group may be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene, and are preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene, and naphthalene. Examples of non-fused aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-tribiphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenyl, 4''-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-dimethylphenyl, mesitylene and m-tetraphenyl. The aryl group may also be substituted.

[0041] Heterocyclic group or heterocycle, as used herein, refers to a non-aromatic cyclic group. Non-aromatic heterocyclic groups include saturated heterocyclic groups having 3 to 20 ring atoms and unsaturated non-aromatic heterocyclic groups having 3 to 20 ring atoms, at least one ring atom of which is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium and boron atoms, and non-aromatic heterocyclic groups preferably have 3 to 7 ring atoms and contain at least one heteroatom such as nitrogen, oxygen, silicon or sulfur. Examples of non-aromatic heterocyclic groups include oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxopentyl, dioxanyl, aziridinyl, dihydropyrrole, tetrahydropyrrolyl, piperidinyl, oxazolidinyl, morpholinyl, piperazinyl, oxacycloheptatrienyl, thiacycloheptatrienyl, azacycloheptatrienyl, and tetrahydrosilole. Heterocyclic groups may also be substituted.

[0042] Heteroaryl groups, as used herein, may include non-fused and fused heteroaromatic groups having 1 to 5 heteroatoms, at least one of which is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron. Isoaryl groups also refer to heteroaryl groups. Heteroaryl groups may be heteroaryl groups having 3 to 30 carbon atoms, preferably heteroaryl groups having 3 to 20 carbon atoms, and more preferably heteroaryl groups having 3 to 12 carbon atoms. Suitable heteroaryl groups are dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridoindole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indenoazine, benzoxazole, benzisoxazole, Heteroaryl groups include benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, benzofuranpyridine, frangipyridine, benzothienopyridine, thienobipyridine, benzoselenopyridine, and selenobenzopyridine, and preferably include dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborane, 1,3-azaborane, 1,4-azaborane, borazole, and their aza analogues. Heteroaryl groups may also be substituted.

[0043] As used herein, the alkoxy group is represented by -O-alkyl group, -O-cycloalkyl group, -O-heteroalkyl group, or -O-heterocyclic group. Examples and preferred examples of the alkyl group, cycloalkyl group, heteroalkyl group, and heterocyclic group are the same as those mentioned above. The alkoxy group may be an alkoxy group having 1 to 20 carbon atoms, and is preferably an alkoxy group having 1 to 6 carbon atoms. Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy, and ethoxymethyloxy. The alkoxy group may be substituted.

[0044] As used herein, the aryloxy group is represented by -O-aryl group or -O-heteroaryl group. Examples and preferred examples of the aryl group and the heteroaryl group are the same as those mentioned above. The aryloxy group may be an aryloxy group having 6 to 30 carbon atoms, and is preferably an aryloxy group having 6 to 20 carbon atoms. Examples of the aryloxy group include phenoxy and biphenoxy. The aryloxy group may be substituted.

[0045] As used herein, the term "aralkyl group" includes an alkyl group substituted with an aryl group. The aralkyl group may be an aralkyl group having 7 to 30 carbon atoms, preferably an aralkyl group having 7 to 20 carbon atoms, and more preferably an aralkyl group having 7 to 13 carbon atoms. Examples of the aralkyl group include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl-tert-butyl, α-naphthylmethyl, 1-α-naphthylethyl, 2-α-naphthylethyl, 1-α-naphthylisopropyl, 2-α-naphthylisopropyl, β-naphthylmethyl, 1-β-naphthyl-ethyl, 2-β-naphthyl-ethyl, 1-β-naphthylisopropyl, 2-β-naphthylisopropyl, p-methylbenzyl, m-methylbenzyl, o-methylbenzyl, p-chlorobenzyl, m-chlorobenzyl, o ... Aralkyl groups include chlorobenzyl, o-chlorobenzyl, p-bromobenzyl, m-bromobenzyl, o-bromobenzyl, p-iodobenzyl, m-iodobenzyl, o-iodobenzyl, p-hydroxybenzyl, m-hydroxybenzyl, o-hydroxybenzyl, p-aminobenzyl, m-aminobenzyl, o-aminobenzyl, p-nitrobenzyl, m-nitrobenzyl, o-nitrobenzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-hydroxy-2-phenylisopropyl and 1-chloro-2-phenylisopropyl. Among them, benzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl and 2-phenylisopropyl are preferred. The aralkyl group may also be substituted.

[0046] As used herein, the term "alkylsilyl group" includes silyl groups substituted with an alkyl group. The alkylsilyl group may be an alkylsilyl group having 3 to 20 carbon atoms, and is preferably an alkylsilyl group having 3 to 10 carbon atoms. Examples of the alkylsilyl group include trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tri-tert-butylsilyl, triisobutylsilyl, dimethyl-tert-butylsilyl, and methyldi-tert-butylsilyl. The alkylsilyl group may also be substituted.

[0047] As used herein, the term "arylsilyl group" includes a silyl group substituted with at least one aryl group. The arylsilyl group may be an arylsilyl group having 6 to 30 carbon atoms, and is preferably an arylsilyl group having 8 to 20 carbon atoms. Examples of the arylsilyl group include triphenylsilyl, phenyl dibiphenylsilyl, diphenyl biphenylsilyl, phenyl diethylsilyl, diphenyl ethylsilyl, phenyl dimethylsilyl, diphenyl methylsilyl, phenyl diisopropylsilyl, diphenyl isopropylsilyl, diphenyl butylsilyl, diphenyl isobutylsilyl, and diphenyl-tert-butylsilyl. The arylsilyl group may be substituted.

[0048] As used herein, the term "alkyl germanium group" includes a germanium group substituted with an alkyl group. The alkyl germanium group may be an alkyl germanium group having 3 to 20 carbon atoms, and is preferably an alkyl germanium group having 3 to 10 carbon atoms. Examples of the alkyl germanium group include a trimethyl germanium group, a triethyl germanium group, a methyldiethyl germanium group, an ethyldimethyl germanium group, a tripropyl germanium group, a tributyl germanium group, a triisopropyl germanium group, a methyldiisopropyl germanium group, a dimethylisopropyl germanium group, a tri-tert-butyl germanium group, a triisobutyl germanium group, a dimethyl-tert-butyl germanium group, and a methyldi-tert-butyl germanium group. The alkyl germanium group may be substituted.

[0049] As used herein, the term "arylgermanium group" includes a germanium group substituted with at least one aryl group or heteroaryl group. The arylgermanium group may be an aryl group germanium group having 6 to 30 carbon atoms, and is preferably an arylgermanium group having 8 to 20 carbon atoms. Examples of the arylgermanium group include a triphenylgermanium group, a phenyldibiphenylgermanium group, a diphenylbiphenylgermanium group, a phenyldiethylgermanium group, a diphenylethylgermanium group, a phenyldimethylgermanium group, a diphenylmethylgermanium group, a phenyldiisopropylgermanium group, a diphenylisopropylgermanium group, a diphenylbutylgermanium group, a diphenylisobutylgermanium group, and a diphenyl-tert-butylgermanium group. The arylgermanium group may also be substituted.

[0050] The "aza" in azadibenzofuran, azadibenzothiophene, etc. refers to the replacement of one or more CH groups in the corresponding aromatic fragment with a nitrogen atom. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline, and other analogs having two or more nitrogens in the ring system. Those skilled in the art can easily imagine other nitrogen analogs of the above-mentioned aza derivatives, and all of these analogs are defined as being included in the terminology described herein.

[0051] In the present invention, unless otherwise specified, the following groups are included: a substituted alkyl group, a substituted cycloalkyl group, a substituted heteroalkyl group, a substituted heterocyclic group, a substituted aralkyl group, a substituted alkoxy group, a substituted aryloxy group, a substituted alkenyl group, a substituted alkynyl group, a substituted aryl group, a substituted heteroaryl group, a substituted alkylsilyl group, a substituted arylsilyl group, a substituted alkylgermanium group, a substituted arylgermanium group, a substituted amino group, a substituted acyl group, a substituted carbonyl group, a substituted carboxyl group, a substituted ester group, a substituted sulfur group, a substituted aryl ... When any of the terms from the group consisting of alkyl, cycloalkyl, heteroalkyl, heterocyclyl, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermanium, arylgermanium, amino, acyl, carbonyl, carboxyl, ester, sulfinyl, sulfonyl, and phosphino groups is used, any one of the following groups is included: alkyl, cycloalkyl, heteroalkyl, heterocyclyl, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermanium, arylgermanium, amino, acyl, carbonyl, carboxyl, ester, sulfinyl, sulfonyl, and phosphino. The group is selected from the group consisting of deuterium, halogen, an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, an unsubstituted heteroalkyl group having 1 to 20 carbon atoms, an unsubstituted heterocyclic group having 3 to 20 ring atoms, an unsubstituted aralkyl group having 7 to 30 carbon atoms, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an unsubstituted aryloxy group having 6 to 30 carbon atoms, an unsubstituted alkenyl group having 2 to 20 carbon atoms, an unsubstituted alkynyl group having 2 to 20 carbon atoms, an unsubstituted aryl group having 6 to 30 carbon atoms, an unsubstituted heptyl group having 3 to 30 carbon atoms, an unsubstituted aryl ... It means that the aryl group may be substituted with one or more selected from a heteroaryl group, an unsubstituted alkylsilyl group having 3 to 20 carbon atoms, an unsubstituted arylsilyl group having 6 to 20 carbon atoms, an unsubstituted alkylgermanium group having 3 to 20 carbon atoms, an unsubstituted arylgermanium group having 6 to 20 carbon atoms, an unsubstituted amino group, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphino group, and combinations thereof.

[0052] When describing a molecular fragment as being attached to another moiety by a substituent or otherwise, it should be understood that the designation can be defined as to whether it is a fragment (e.g., a phenyl group, a phenylene group, a naphthyl group, a dibenzofuranyl group) or an entire molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, the designations of the substituents or different modes of attachment of the fragment are recognized as equivalents.

[0053] In the compounds mentioned herein, hydrogen atoms may be partially or completely replaced by deuterium.Other atoms, such as carbon and nitrogen, may also be replaced by their other stable isotopes.In order to improve the efficiency and stability of the device, the replacement of other stable isotopes in the compounds may be preferred.

[0054] In the compounds referred to herein, multiple substitution refers to the range up to the most available substitution, including double substitution.When a substituent in a compound referred to herein means multiple substitution (including double substitution, triple substitution, quadruple substitution, etc.), it means that the substituent can be present at multiple available substitution positions on the bond structure, and the substituents present at multiple available substitution positions can be the same structure or different structures.

[0055] Unless otherwise specifically limited, adjacent substituents in the compounds mentioned herein may be bonded to form a ring, adjacent substituents in the compounds may not be bonded to form a ring. In the compounds mentioned herein, adjacent substituents may be bonded to form a ring, including not only the situation where adjacent substituents may be bonded to form a ring, but also the situation where adjacent substituents do not bond to form a ring. When adjacent substituents may be bonded to form a ring, the ring formed may be a monocyclic or polycyclic ring, and an alicyclic ring, a heteroalicyclic ring, an aryl ring, or a heteroaryl ring. In such a description, adjacent substituents may refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to carbon atoms further apart. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0056] The statement that adjacent substituents may be bonded to form a ring is also understood to mean that two substituents bonded to the same carbon atom are bonded to each other by a chemical bond to form a ring, which can be exemplified by the following formula: [ka]

[0057] The statement that adjacent substituents may be bonded to form a ring is also understood to mean that two substituents bonded to carbon atoms that are directly bonded to each other are bonded to each other by a chemical bond to form a ring, which can be exemplified by the following formula: [ka]

[0058] The statement that adjacent substituents may be bonded to form a ring is also understood to mean that two substituents bonded to carbon atoms further apart are bonded to each other by a chemical bond to form a ring, which can be exemplified by the following formula: [ka]

[0059] In addition, the statement that adjacent substituents may be bonded to form a ring is also recognized as meaning that when one of two substituents bonded to carbon atoms directly bonded to each other represents hydrogen, the second substituent is bonded to the position to which the hydrogen atom is bonded to form a ring. The following formula is an example. [ka]

[0060] According to one embodiment of the present invention, there is provided an organic electroluminescent device, comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer includes a first organic layer and a second organic layer; the first organic layer comprises a first organic material and a first p-type dopant; the second organic layer comprises a second organic material and a second p-type dopant; the first organic layer is in contact with a second organic layer, the second organic layer overlying the first organic layer; An organic electroluminescent device is disclosed, wherein the first p-type dopant and the second p-type dopant each independently have a structure represented by Formula 1: [ka] (n is an integer selected from 1 to 5, Ring A is the same or different at each occurrence and is selected from conjugated rings having 4 to 30 ring atoms; R3 represents mono-, poly- or no substitution; R1, R2 and R3 are the same or different at each occurrence and are selected from hydrogen, deuterium or a substituent; At least one R3 is selected from hydrogen, deuterium, or a substituent containing at least two atoms; Adjacent substituents R1, R2, and R3 may be bonded to form a ring.

[0061] In the present specification, "ring A is a conjugated ring having 4 to 30 ring atoms" means that ring A is a cyclic structure having 4 to 30 ring atoms, and ring A has a conjugated structural feature. Exemplarily, ring A includes, but is not limited to, structures represented by formulas 2 to 13 in the present application. The ring A may be a monocyclic structure or a polycyclic structure. Among them, the polycyclic ring may be a bonded ring structure or a condensed ring structure, or may be a totally conjugated structure formed by bonding two conjugated rings with a double bond, for example, a structure represented by formula 13 in the present application. The ring A may be a carbon ring or a hetero ring.

[0062] In this specification, "adjacent substituents R1, R2, and R3 may be bonded to form a ring" means that any one or more of adjacent substituent groups, such as the substituents R3, the substituents R1 and R2, the substituents R1 and R3, and the substituents R2 and R3, may be bonded to form a ring. Obviously, none of these substituents may be bonded to form a ring.

[0063] According to one embodiment of the present invention, n is selected from 1, 2 or 3.

[0064] According to one embodiment of the present invention, n is selected from 1 or 2.

[0065] According to one embodiment of the present invention, ring A is identical or different at each occurrence and is selected from conjugated rings having 4 to 20 ring atoms.

[0066] According to one embodiment of the present invention, ring A is identical or different at each occurrence and is selected from conjugated rings having 4 to 15 ring atoms.

[0067] According to one embodiment of the present invention, ring A is selected from the group consisting of formulae 2 to 13, each occurrence being the same or different: [ka] X is, at each occurrence, identically or differently selected from the group consisting of N and CR3; W at each occurrence is identically or differently selected from the group consisting of O, S, Se, and NR3; At least one R3 is selected from hydrogen, deuterium, or a substituent containing at least two atoms; Adjacent substituents R1, R2, and R3 may be bonded to form a ring; [ka] represents the bonding site of the double bond in formulae 2 to 13 and 1.

[0068] According to one embodiment of the present invention, the p-type dopant has a structure represented by any one of the following formulas 14 to 17. [ka] (X1, X2, X3 and X4 are identically or differently selected from the group consisting of N and CR3 at each occurrence; W at each occurrence is identically or differently selected from the group consisting of O, S, Se, and NR3; R1, R2 and R3 are the same or different at each occurrence and are selected from hydrogen, deuterium or a substituent; At least one R3 is selected from hydrogen, deuterium, or a substituent containing at least two atoms; Adjacent substituents R1, R2, and R3 may be bonded to form a ring.

[0069] According to one embodiment of the present invention, W, at each occurrence, is identical or different and is selected from O, S or Se.

[0070] According to one embodiment of the invention, W is selected from O or S, identically or differently at each occurrence.

[0071] According to one embodiment of the present invention, W is selected from O.

[0072] According to one embodiment of the present invention, W is selected from NR3, and R3 is selected from the group consisting of substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl groups having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, and combinations thereof.

[0073] According to one embodiment of the present invention, W at each occurrence is the same or different and is selected from NR3, and R3 at each occurrence is the same or different and is selected from the group consisting of substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, and combinations thereof.

[0074] According to one embodiment of the present invention, the substituent is selected from the group consisting of halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 3 ... The alkyl group is selected from the group consisting of an aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanium group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxy group, sulfanyl group, sulfinyl group, sulfonyl group, phosphino group, and combinations thereof.

[0075] According to one embodiment of the present invention, at least one R3 is selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted carbon The group consisting of an aryl group having 6 to 30 atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanium group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxy group, sulfanyl group, sulfinyl group, sulfonyl group, phosphino group, and combinations thereof, each of which is selected from the group consisting of an aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxy group, sulfanyl group, sulfinyl group, sulfonyl group, phosphino group, and combinations thereof.

[0076] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is less than or equal to 100 nm.

[0077] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is less than or equal to 50 nm.

[0078] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is less than or equal to 30 nm.

[0079] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is less than or equal to 20 nm.

[0080] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is equal to or greater than 5 nm.

[0081] According to one embodiment of the present invention, the sum of the thicknesses of the first organic layer and the second organic layer is equal to or greater than 10 nm.

[0082] According to one embodiment of the present invention, the first organic material and the second organic material are the same.

[0083] According to one embodiment of the present invention, the first organic material and the second organic material are different.

[0084] According to one embodiment of the present invention, the first p-type dopant and the second p-type dopant are the same.

[0085] According to one embodiment of the present invention, the first p-type dopant and the second p-type dopant are different.

[0086] According to one embodiment of the present invention, the doping rate of the first p-type dopant in the first organic layer is less than the doping rate of the second p-type dopant in the second organic layer.

[0087] A lightly doped p-type dopant in the first organic layer (i.e., the bottom layer closer to the anode) can be used to control the number of hole injections, while a heavy p-type dopant in the second organic layer (i.e., the top layer closer to the cathode) can be used to balance the number of hole injections.

[0088] According to one embodiment of the present invention, the doping rate of the first p-type dopant in the first organic layer is equal to or greater than the doping rate of the second p-type dopant in the second organic layer.

[0089] According to one embodiment of the present invention, the LUMO of the first p-type dopant is greater than or equal to −5.2 eV.

[0090] According to one embodiment of the present invention, the LUMO of the first p-type dopant is greater than or equal to −5.0 eV.

[0091] According to one embodiment of the present invention, the LUMO of the first p-type dopant is greater than or equal to −4.9 eV.

[0092] According to one embodiment of the present invention, the LUMO of the second p-type dopant is greater than or equal to −5.2 eV.

[0093] According to one embodiment of the present invention, the LUMO of the second p-type dopant is greater than or equal to −5.0 eV.

[0094] According to one embodiment of the present invention, the LUMO of the second p-type dopant is greater than or equal to −4.9 eV.

[0095] According to an embodiment of the present invention, the LUMO of the first p-type dopant and / or the second p-type dopant is less than or equal to -4.2 eV.

[0096] According to an embodiment of the present invention, the LUMO of the first p-type dopant and / or the second p-type dopant is less than or equal to -4.3 eV.

[0097] According to an embodiment of the present invention, the LUMO of the first p-type dopant and / or the second p-type dopant is less than or equal to -4.5 eV.

[0098] According to one embodiment of the present invention, the LUMO of the first p-type dopant is lower than or equal to the LUMO of the second p-type dopant.

[0099] According to one embodiment of the present invention, the LUMO of the first p-type dopant is greater than the LUMO of the second p-type dopant.

[0100] According to one embodiment of the present invention, the HOMO energy level of the first organic material and / or the second organic material is less than or equal to −4.5 eV.

[0101] According to one embodiment of the present invention, the HOMO energy level of the first organic material and / or the second organic material is less than or equal to −4.8 eV.

[0102] According to one embodiment of the present invention, the first organic material and / or the second organic material is selected from the group consisting of compounds having triarylamine units, spirobifluorene-based compounds, pentacene-based compounds, oligothiophene-based compounds, oligophenyl compounds, oligophenyleneethylene compounds, oligofluorene-based compounds, porphyrin complexes, and metal phthalocyanine complexes.

[0103] According to an embodiment of the present invention, the doping rate of the first p-type dopant in the first organic layer is ≧0.01% and ≦99.9%.

[0104] According to an embodiment of the present invention, the doping rate of the first p-type dopant in the first organic layer is ≧0.1% and ≦99.9%.

[0105] According to an embodiment of the present invention, the doping rate of the first p-type dopant in the first organic layer is ≧0.5% and ≦50%.

[0106] According to an embodiment of the present invention, the doping rate of the second p-type dopant in the second organic layer is ≧0.01% and ≦99.9%.

[0107] According to an embodiment of the present invention, the doping rate of the second p-type dopant in the second organic layer is ≧0.1% and ≦99.9%.

[0108] According to an embodiment of the present invention, the doping rate of the second p-type dopant in the second organic layer is ≧0.5% and ≦50%.

[0109] According to an embodiment of the present invention, the semiconductor device further includes a third organic layer on the second organic layer, the third organic layer including a third organic material and a third p-type dopant.

[0110] According to an embodiment of the present invention, the third organic material and the first organic material and / or the second organic material may be the same or different.

[0111] According to an embodiment of the present invention, the third p-type dopant and the first p-type dopant and / or the second p-type dopant are the same or different.

[0112] According to one embodiment of the present invention, the definition of the third organic material is the same as the first organic material and / or the second organic material described above.

[0113] According to an embodiment of the present invention, the definition of the third p-type dopant is the same as the first p-type dopant and / or the second p-type dopant described above.

[0114] According to an embodiment of the present invention, the organic electroluminescent device has two or more organic layers containing p-type dopant, for example, three, four or five organic layers containing p-type dopant. When the organic electroluminescent device has two or more organic layers containing p-type dopant, for example, a third organic layer is further included on the second organic layer. The third organic layer contains a third organic material and a third p-type dopant. The doping rate of the p-type dopant in the two or more organic layers may increase with a gradient along the direction from the anode to the cathode, may decrease with a gradient along the direction from the anode to the cathode, or may change parabolically (i.e., the doping rate increases and then decreases, or decreases and then increases). If necessary, the doping rates may be consistent.

[0115] According to one embodiment of the present invention, the first organic material, the second organic material and the third organic material are all hole transport materials.

[0116] According to one embodiment of the present invention, R1 and / or R2 are substituents comprising at least one electron-withdrawing group.

[0117] According to one embodiment of the present invention, the Hammett constant of the electron-withdrawing group is 0.05 or more, preferably 0.3 or more, more preferably 0.5 or more.

[0118] The electron-withdrawing group in the present invention has a Hammett substituent constant value of 0.05 or more, for example, 0.1 or more or 0.2 or more, preferably 0.3 or more, and more preferably 0.5 or more. Since the electron-withdrawing ability is strong, the LUMO energy level of the compound can be significantly lowered and the effect of improving the charge mobility can be achieved.

[0119] The Hammett substituent constant value includes a Hammett substituent para-position constant and / or a Hammett substituent meta-position constant. If both the para-position constant and the meta-position constant are greater than 0, and one of them is 0.05 or greater, the group can be selected in the present invention.

[0120] According to one embodiment of the present invention, the electron-withdrawing group is a C1-C20 substituted with one or more of halogen, nitroso, nitro, acyl, carbonyl, carboxyl, ester, cyano, isocyano, SCN, OCN, SF5, boranyl, sulfinyl, sulfonyl, phosphonoxy, or aza aromatic ring group, or a C1-C20 substituted with one or more of halogen, nitroso, nitro, acyl, carbonyl, carboxyl, ester, cyano, isocyano, SCN, OCN, SF5, boranyl, sulfinyl, sulfonyl, phosphonoxy, or aza aromatic ring group. the alkyl group having from 3 to 20 ring atoms, the cycloalkyl group having from 3 to 20 ring atoms, the heteroalkyl group having from 1 to 20 carbon atoms, the heterocyclic group having from 3 to 20 ring atoms, the aralkyl group having from 7 to 30 carbon atoms, the alkoxy group having from 1 to 20 carbon atoms, the aryloxy group having from 6 to 30 carbon atoms, the alkenyl group having from 2 to 20 carbon atoms, the alkynyl group having from 2 to 20 carbon atoms, the aryl group having from 6 to 30 carbon atoms, the heteroaryl group having from 3 to 30 carbon atoms, the alkylsilyl group having from 3 to 20 carbon atoms, and the arylsilyl group having from 6 to 20 carbon atoms, as well as any one of these groups and combinations thereof.

[0121] According to one embodiment of the present invention, the electron-withdrawing group is a halogen, a nitroso group, a nitro group, an acyl group, a carbonyl group, a carboxyl group, an ester group, SF5, a boranyl group, a sulfinyl group, a sulfonyl group, a phosphonoxy group, an aza aromatic ring group, or an aryl group having 1 to 20 carbon atoms substituted with one or more of a halogen, a nitroso group, a nitro group, an acyl group, a carbonyl group, a carboxyl group, an ester group, a cyano group, an isocyano group, SCN, OCN, SF5, a boranyl group, a sulfinyl group, a sulfonyl group, a phosphonoxy group, an aza aromatic ring group. and combinations thereof.

[0122] According to one embodiment of the present invention, the electron-withdrawing group is selected from the group consisting of fluorine, an acyl group, a carbonyl group, an ester group, SF5, a boranyl group, an azaaromatic ring group, and any one of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 ring carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 3 to 30 carbon atoms, an alkylsilyl group having 3 to 20 carbon atoms, and an arylsilyl group having 6 to 20 carbon atoms, each of which is substituted with one or more of fluorine, cyano, isocyano, SCN, OCN, SF5, CF3, OCF3, SCF3, and an azaaromatic ring group, and combinations thereof.

[0123] According to one embodiment of the present invention, the p-type dopant is selected from the group consisting of, but not limited to, the following structures: [ka] [ka] [ka] [ka] [ka]

[0124] According to one embodiment of the present invention, the first organic layer is in contact with the anode.

[0125] According to an embodiment of the present invention, the organic electroluminescent device further includes at least one light-emitting layer, the light-emitting layer being disposed between the second organic layer and the cathode.

[0126] According to an embodiment of the present invention, the light-emitting layer contains a light-emitting material, and the light-emitting material is a phosphorescent, fluorescent or delayed fluorescent light-emitting material.

[0127] According to one embodiment of the present invention, the organic electroluminescent element further includes a fourth organic layer containing the first organic material or the second organic material, disposed between the second organic layer and the light-emitting layer.

[0128] According to an embodiment of the present invention, the organic electroluminescent device further includes a charge generating layer, which includes a p-type charge generating layer, disposed between the light emitting layer and the cathode.

[0129] According to one embodiment of the present invention, the p-type charge generating layer of the charge generating layer contains a first p-type dopant or a second p-type dopant.

[0130] According to an embodiment of the present invention, in the charge generating layer, the doping rate of the first p-type dopant or the second p-type dopant in the p-type charge generating layer is 0.01% or more and 100% or less.

[0131] According to one embodiment of the present invention, the p-type charge generating layer of the charge generating layer contains the p-type dopant.

[0132] According to one embodiment of the present invention, the p-type charge generating layer of the charge generating layer may be the first organic layer.

[0133] According to one embodiment of the present invention, the first organic layer or the second organic layer contacts the p-type charge generating layer of the charge generating layer.

[0134] According to one embodiment of the present invention, the organic electroluminescence device has a structure of a single layer device of anode / first organic layer / second organic layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode. Among them, the electron blocking layer and the hole blocking layer are optional layers and can be selected according to need. Among them, the layer structure is not limited to a single layer structure, for example, the light emitting layer therein may be a two-layer structure, that is, it may include two light emitting layers. Between the second organic layer and the hole transport layer, the third organic layer of the present invention is further included.

[0135] According to one embodiment of the present invention, the organic electroluminescent device has a laminated element structure of anode / first light-emitting unit / charge generation layer / second light-emitting unit / cathode. Wherein, the first light-emitting unit and the second light-emitting unit may be the same or different, and each independently has an organic layer structure between the anode and the cathode in the above single-layer device structure. Between the second light-emitting unit and the cathode, a first charge generation layer and a third light-emitting unit, that is, an element structure of anode / first light-emitting unit / charge generation layer / second light-emitting unit / first charge generation layer / third light-emitting unit / cathode may be further included. Wherein, the third light-emitting unit and the first light-emitting unit may be the same or different, and the third light-emitting unit and the second light-emitting unit may also be the same or different.

[0136] According to one embodiment of the present invention, the first organic material and / or the second organic material includes one or more chemical structural units selected from the group consisting of triarylamine, carbazole, fluorene, spirobifluorene, thiophene, furan, phenyl, oligophenyleneethylene, oligofluorene, and combinations thereof.

[0137] According to one embodiment of the present invention, the first organic material and / or the second organic material comprises monotriarylamine structural units or bistriarylamine structural units.

[0138] According to one embodiment of the present invention, the first organic material and / or the second organic material includes one or more chemical structural units selected from the group consisting of a monotriarylamine-carbazole structural unit, a monotriarylamine-thiophene structural unit, a monotriarylamine-furan structural unit, a monotriarylamine-fluorene structural unit, a bistriarylamine-carbazole structural unit, a bistriarylamine-thiophene structural unit, a bistriarylamine-furan structural unit, and a bistriarylamine-fluorene structural unit.

[0139] According to an embodiment of the present invention, the first organic material and / or the second organic material is a monotriarylamine compound or a bistriarylamine compound.

[0140] According to an embodiment of the present invention, the first organic material and / or the second organic material is selected from monotriarylamine-carbazole compounds, monotriarylamine-thiophene compounds, monotriarylamine-furan compounds, monotriarylamine-fluorene compounds, bistriarylamine-carbazole compounds, bistriarylamine-thiophene compounds, bistriarylamine-furan compounds, and bistriarylamine-fluorene compounds.

[0141] According to one embodiment of the present invention, the first organic material and / or the second organic material containing the monotriarylamine structural unit has a structure represented by Formula 18 or Formula 19. [ka] (Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6 each occurrence may be the same or different and each occurrence may be selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and the structures of Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6 do not include carbazole, L1, L2, L3 and L4 each appearing are the same or different and are selected from a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms, or a combination thereof, and the structures of L1, L2, L3 and L4 do not include carbazole; R, when present, is the same or different and represents mono-, multi- or no substitution; R each occurrence may be the same or different and is hydrogen, deuterium, a halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanium group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxyl group, an ester group, a cyano group, an isocyano group, a hydroxy group, a sulfanyl group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; Adjacent substituents may be bonded to form a ring.

[0142] According to one embodiment of the present invention, Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6, each occurrence being the same or different, are selected from substituted or unsubstituted phenyl group, substituted or unsubstituted biphenyl group, substituted or unsubstituted terphenyl group, substituted or unsubstituted naphthalene group, substituted or unsubstituted dibenzofuran group, substituted or unsubstituted dibenzothiophene group, substituted or unsubstituted dibenzoselenophene group, substituted or unsubstituted phenanthrene group, substituted or unsubstituted triphenylene group, substituted or unsubstituted pyridine group, substituted or unsubstituted anthracene group, substituted or unsubstituted pyrene group, substituted or unsubstituted fluorene group, or combinations thereof.

[0143] According to one embodiment of the present invention, L1, L2, L3 and L4, each occurrence being the same or different, are selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted dibenzofuranylene group, a substituted or unsubstituted dibenzothienylene group, a substituted or unsubstituted dibenzoselenophene group, a substituted or unsubstituted phenanthrylene group, a substituted or unsubstituted triphenylenylene group, a substituted or unsubstituted pyridinylene group, a substituted or unsubstituted anthracenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted fluorenylene group, or a combination thereof.

[0144] According to one embodiment of the present invention, the first organic material and / or the second organic material containing a bistriarylamine structural unit has a structure represented by Formula 20: [ka] (Ar7, Ar8, Ar9 and Ar 10 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; L5 is selected from a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms; Adjacent substituents may be bonded to form a ring.

[0145] According to one embodiment of the present invention, Ar7, Ar8, Ar9 and Ar 10are the same or different at each occurrence and are selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthalene group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, a substituted or unsubstituted dibenzoselenophene group, a substituted or unsubstituted phenanthrene group, a substituted or unsubstituted triphenylene group, a substituted or unsubstituted pyridine group, a substituted or unsubstituted anthracene group, a substituted or unsubstituted pyrene group, a substituted or unsubstituted fluorene group, or combinations thereof.

[0146] According to one embodiment of the present invention, L5 is selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted carbazolylene group, a substituted or unsubstituted dibenzofuranylene group, a substituted or unsubstituted dibenzothienylene group, a substituted or unsubstituted dibenzoselenophene group, a substituted or unsubstituted phenanthrylene group, a substituted or unsubstituted triphenylenylene group, a substituted or unsubstituted pyridinylene group, a substituted or unsubstituted anthracenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted fluorenylene group, or a combination thereof.

[0147] According to one embodiment of the present invention, the first organic material and / or the second organic material is selected from the group consisting of, but not limited to, the following structures: [ka] [ka] [ka] [ka]

[0148] According to one embodiment of the present invention, there is disclosed an electronic assembly including an organic electroluminescent device according to any one of the above embodiments.

[0149] In terms of the device structure, OLEDs can be divided into a normal single-layer structure and a tandem structure (also called a stacked structure). A normal single-layer OLED contains only one light-emitting unit between a cathode and an anode, while a tandem OLED is composed of a plurality of light-emitting units stacked together. A light-emitting unit generally contains at least one light-emitting layer, one hole transport layer and one electron transport layer. The light-emitting unit may further contain a hole injection layer, an electron injection layer, a hole blocking layer and an electron blocking layer. It should be noted that a normal single-layer OLED contains only one light-emitting unit, but the light-emitting unit may contain multiple light-emitting layers, for example, the light-emitting unit may contain one yellow light-emitting layer and one blue light-emitting layer. However, each light-emitting unit can only contain one pair of hole transport layers and electron transport layers. A tandem OLED contains at least two or more light-emitting units, that is, it contains at least two pairs and more than two pairs of hole transport layers and electron transport layers. Here, the light-emitting units are arranged in a physical form of vertical stacking, thereby realizing the feature of series connection on a circuit, so it may be called a series-connected OLED (from circuit connection) or a stacked OLED (from physical form). At the same brightness, the current density required for the tandem OLED is smaller than that of a normal single-layer OLED, so the effect of improving the service life can be achieved. Conversely, at a constant current density, the brightness of the tandem OLED may be higher than that of a normal single-layer OLED, and the voltage may be improved accordingly. In the tandem OLED, adjacent light-emitting units are connected by a charge generation layer, and the quality of the charge generation layer directly affects the parameters such as the voltage, service life and efficiency of the tandem OLED. Therefore, the charge generation layer region needs to effectively generate holes and electrons and smoothly inject them into the corresponding light-emitting units, and the larger the transmittance in the visible light range, the more stable the performance and easy to manufacture.

[0150] Currently, commercial OLED structures usually contain only one hole injection layer (HIL), i.e., one p-type dopant (PD) is used to dope a hole transporting host material (HTM) in a certain ratio to form the HIL, or a single material is used to form the HIL, e.g., the compound HATCN. [ka] However, such a single layer structure is easy to reduce the service life of the device after operating for a long time. In order to balance the carriers in the device, some prior art discloses a HIL including multiple layers, which usually includes only one p-type doped organic layer and another layer using a pure p-type material to promote hole injection. However, the pure p-type material has a limited ability to adjust and control hole injection because the hole injection ability can not be controlled and can be adjusted and controlled only by changing the doping concentration of one of the p-type materials. In order to balance the number of electrons and holes in the OLED and solve the above-mentioned problems, the present application provides at least two organic layers containing p-type dopants, and such a structure achieves a significant effect in improving the overall performance of the device.

[0151] In this specification, the LUMO energy level (lowest unoccupied molecular orbital) and HOMO energy level (highest occupied molecular orbital) of a compound are measured by cyclic voltammetry. A specific method is to use an electrochemical station, model number CorrTestCS120, manufactured by Wuhan Science Instrument Co., Ltd., and a three-electrode working system is used, with a platinum disk electrode as the working electrode, an Ag / AgNO3 electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode. Anhydrous DCM is used as the solvent and 0.1 mol / L tetrabutylammonium hexafluorophosphate is used as the supporting electrolyte, and the target compound is dissolved in 10 -3A solution of 1.2 mol / L was prepared, and before the test, nitrogen gas was introduced into the solution for 10 min to remove oxygen. The instrument parameters were set as follows: scan rate 100 mV / s, potential interval 0.5 mV, test window 1 V to -0.5 V. The LUMO energy levels of some p-type dopants and HOMO energy levels of organic materials were measured according to the above test method, and the data are listed in Table 1 below.

[0152] [Table 1]

[0153] It is stated herein that the materials of specific layers used in the organic light-emitting device can be used in combination with many other materials present in the device. Illustratively, the compounds disclosed herein can be used in combination with multiple light-emitting dopants, hosts, transport layers, blocking layers, injection layers, electrodes, and other possible layers. These combinations of materials are described in detail in paragraphs 0080-0101 of US Patent Application US2015 / 0349273A1, the contents of which are incorporated herein by reference in their entirety. The materials described or mentioned are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily refer to the literature to identify other materials that can be used in combination.

[0154] In the device examples, the characteristics of the devices were also tested using equipment common in the art (including but not limited to an evaporation machine manufactured by Angstrom Engineering, an optical test system and a service life test system manufactured by Suzhou Fusida, an ellipsometer manufactured by Beijing Liangtuo, etc.) in a manner familiar to those skilled in the art. Those skilled in the art are familiar with the use of the above-mentioned equipment, the test methods, and other related content, and can reliably and unaffectedly obtain the specific data of the samples, so the above-mentioned related content will not be repeated in this specification. EXAMPLES

[0155] The following will be described in detail with some examples to illustrate the working principle of the organic electroluminescence device. Obviously, the following examples are only for illustrative purposes, and are not intended to limit the scope of the present invention. Based on the following examples, those skilled in the art can obtain other embodiments of the present invention through modification.

[0156] Example 1-1

[0157] An organic electroluminescence device 300 including the first and second organic layers according to the present invention shown in FIG. 3 was manufactured. (While the hole blocking layer 160 is omitted in this embodiment, those skilled in the art can add a hole blocking layer as necessary). The specific method is as follows. First, a glass substrate 101 having an indium tin oxide (ITO) anode 110 with a thickness of 1200 Å was cleaned and then treated with UV ozone and oxygen plasma. After treatment, the substrate was dried in a glove box filled with nitrogen gas to remove water. Then, the substrate was mounted on a substrate holder and placed in a vacuum chamber. The vacuum level was about 10. -8In the case of Torr, deposition was performed on the ITO anode in sequence by hot vacuum deposition at a rate of 0.01 to 10 Å / s. First, HT-18 and compound 3-1 were co-deposited and used as the first organic layer 120a. Among them, the doping rate of compound 3-1 was 2%, and the thickness of the first organic layer 120a was 20 Å. Then, HT-18 and compound 1-2 were co-deposited in the first organic layer 120a and used as the second organic layer 120b. Among them, the doping rate of compound 1-2 was 16%, and the thickness of the second organic layer 120b was 80 Å. Both the first organic layer 120a and the second organic layer 120b were used as the hole injection layer 120, and the total thickness was 100 Å. Then, compound HT-18 is evaporated to be used as hole transport layer (HTL) 130, and the thickness of the hole transport layer (HTL) 130 is 400 Å. Compound EB is evaporated to be used as electron blocking layer (EBL) 140, and the thickness of the electron blocking layer (EBL) 140 is 50 Å. Next, red light emitting dopant compound D-1 is doped into host compound RH to form red light emitting layer (EML) 150. Among them, the doping rate of compound D-1 is 3%, and the thickness of the red light emitting layer (EML) 150 is 400 Å. Then, compounds ET and LiQ are co-evaporated to be used as electron transport layer (ETL) 170, and the thickness of the electron transport layer (ETL) 170 is 350 Å, and the doping rate of LiQ is 60%. On the ETL, 10 Å of LiQ is evaporated to be used as electron injection layer (EIL) 180. Finally, 1200 Å of Al was evaporated to serve as the cathode 190. The evaporated device was transferred to a glove box and encapsulated with a glass cover 102 to complete the device.

[0158] Example 1-2

[0159] The preparation process of Example 1-2 is similar to that of Example 1-1, except that the doping rate of compound 3-1 in the first organic layer 120a is 3%.

[0160] Examples 1-3

[0161] The preparation process of Example 1-3 is similar to that of Example 1-1, except that the first organic layer 120a is composed of the compound HT-18 and the compound 3-1, the doping rate of the compound 3-1 is 0.5%, and the thickness of the first organic layer 120a is 80 Å, the second organic layer 120b is also composed of the compound HT-18 and the compound 3-1, the doping rate of the compound 3-1 is 3%, and the thickness of the second organic layer 120b is 20 Å.

[0162] Examples 1-4

[0163] The preparation process of Example 1-4 is similar to that of Example 1-1, except that the first organic layer 120a is composed of the compound HT-18 and the compound 1-2, the doping rate of the compound 1-2 is 16%, and the thickness of the first organic layer 120a is 80 Å, the second organic layer 120b is also composed of the compound HT-18 and the compound 1-2, the doping rate of the compound 1-2 is 30%, and the thickness of the second organic layer 120b is 20 Å.

[0164] Examples 1-5

[0165] The preparation process of Example 1-5 is similar to that of Example 1-1, except that the first organic layer 120a is composed of compound HT-18 and compound 4-5, the doping rate of compound 4-5 is 3%, the thickness of the first organic layer 120a is 80 Å, the second organic layer 120b is composed of compound HT-18 and compound 1-2, the doping rate of compound 1-2 is 12%, and the thickness of the second organic layer 120b is 20 Å.

[0166] Examples 1-6

[0167] The preparation process of Example 1-6 is similar to that of Example 1-1, except that the first organic layer 120a is composed of the compound HT-18 and the compound 1-2, the doping rate of the compound 1-2 is 30%, and the thickness of the first organic layer 120a is 50 Å; the second organic layer 120b is composed of the compound HT-18 and the compound 1-2, the doping rate of the compound 1-2 is 16%, and the thickness of the second organic layer 120b is 50 Å.

[0168] Comparative Example 1-1

[0169] The preparation process of Comparative Example 1-1 is the same as that of Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 3-1, the doping rate of compound 3-1 is 0.5%, and the thickness of the hole injection layer 120 is 100 Å.

[0170] Comparative Example 1-2

[0171] The preparation process of Comparative Example 1-2 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 3-1, the doping rate of compound 3-1 is 2%, and the thickness of the hole injection layer 120 is 100 Å.

[0172] Comparative Example 1-3

[0173] The preparation process of Comparative Example 1-3 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 3-1, the doping rate of compound 3-1 is 3%, and the thickness of the hole injection layer 120 is 100 Å.

[0174] Comparative Example 1-4

[0175] The preparation process of Comparative Example 1-4 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 1-2, the doping rate of compound 1-2 is 12%, and the thickness of the hole injection layer 120 is 100 Å.

[0176] Comparative Examples 1-5

[0177] The preparation process of Comparative Example 1-5 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 1-2, the doping rate of compound 1-2 is 16%, and the thickness of the hole injection layer 120 is 100 Å.

[0178] Comparative Examples 1-6

[0179] The preparation process of Comparative Example 1-6 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and compound 4-5, the doping rate of compound 4-5 is 3%, and the thickness of the hole injection layer 120 is 100 Å.

[0180] Comparative Example 1-7

[0181] The preparation process of Comparative Example 1-7 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and the compound PD1, the doping rate of the compound PD1 is 16%, and the thickness of the hole injection layer 120 is 100 Å.

[0182] Comparative Example 1-8

[0183] The preparation process of Comparative Example 1-8 is the same as that of Comparative Example 1-1, except that the hole injection layer 120 is co-deposited with HT-18 and the compound PD1, the doping rate of the compound PD1 is 30%, and the thickness of the hole injection layer 120 is 100 Å.

[0184] Comparative Example 1-9

[0185] The preparation process of Comparative Example 1-9 is similar to that of Example 1-1, except that the first organic layer 120a is made of the compound HT-18 and the compound PD1, the doping rate of the compound PD1 is 30%, and the thickness of the first organic layer 120a is 50 Å, the second organic layer 120b is made of the compound HT-18 and the compound PD1, the thickness of the second organic layer 120b is 50 Å, and the doping rate of the compound PD1 is 16%.

[0186] Comparative Example 1-10

[0187] The preparation process of Comparative Example 1-10 is similar to that of Example 1-1, except that the first organic layer 120a is made of compound 3-1, the thickness of the first organic layer 120a is 80 Å, the second organic layer 120b is made of compound HT-18 and compound 3-1, the doping rate of compound 3-1 is 3%, and the thickness of the second organic layer 120b is 20 Å.

[0188] Comparative Example 1-11

[0189] The preparation process of Comparative Example 1-11 is similar to that of Example 1-1, except that the first organic layer 120a is composed of the compound HT-18 and the compound 3-1, the doping rate of the compound 3-1 is 3%, and the thickness of the first organic layer 120a is 20 Å, the second organic layer 120b is composed of the compound 3-1, and the thickness of the second organic layer 120b is 80 Å.

[0190] Details of the first organic layer and the second organic layer in the devices of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-11 are shown in Table 2. Layers using more than one material are obtained by doping different compounds in the weight ratios described above.

[0191] [Table 2]

[0192] The structure of the compound used in the device is shown below. [ka]

[0193] The performance of the elements in Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-11 was measured. Among them, the color coordinate (CIE), voltage and external quantum efficiency (EQE) were measured at a current density of 10 mA / cm 2 The device's service life (LT97) is measured under conditions of 80mA / cm 2 This is the actual measured time for the luminance to decay to 97% of the initial luminance under driving at a constant current density of 100 Hz. These data are shown in Table 3.

[0194] [Table 3]

[0195] As can be seen from the device data in Table 3, the color coordinates for the examples and comparative examples shown were nearly identical.

[0196] An OLED with high EQE, low voltage and long service life is a good device that is desired, but when both cannot be achieved at the same time, the overall performance of the device needs to be considered. In Example 1-1, the first organic layer and the second organic layer are in contact with each other, the first organic layer is composed of the first p-type dopant compound 3-1 and HT-18, and the doping rate is 2%, and the second organic layer is composed of the second p-type dopant compound 1-2 and HT-18, and the doping rate is 16%. In Example 1-1, a high EQE of 27.8%, an ultra-long service life of 283h, and a driving voltage of 3.1V are obtained. The results of comparing Example 1-1, Comparative Example 1-2 and Comparative Example 1-5 are as follows: (1) Comparative Example 1-2 contains only one p-type doping layer, and the doping layer is the same as the first organic layer in Example 1-1 (the materials used and the doping rate are both the same). Example 1-1 has a slightly improved EQE of 2% and a significantly improved service life of 31% compared to Comparative Example 1-2. (2) Comparative Example 1-5 includes only one p-type doping layer, which is the same as the second organic layer in Example 1-1 (the materials and doping ratios used are both the same). Example 1-1 has a lower voltage than Comparative Example 1-5, with a voltage drop of 0.9V, and more surprisingly, its service life is significantly improved, increasing by 466%. Although Example 1-1 has a lower EQE than Comparative Example 1-5, it achieves a high EQE of 27.8%, which has already become a high efficiency level in the industry. Since Comparative Example 1-5 has a high voltage and a very short service life, Example 1-1 is a device with better overall performance.

[0197] In Example 1-2, the first organic layer and the second organic layer are in contact with each other, the first organic layer is composed of the first p-type dopant compound 3-1 and HT-18, and the doping rate is 3%, and the second organic layer is composed of the second p-type dopant compound 1-2 and HT-18, and the doping rate is 16%. In Example 1-2, a high EQE of 27.4%, a low driving voltage of 3.1V, and an extremely long service life of 298h are obtained. The results of comparing Example 1-2, Comparative Example 1-3, and Comparative Example 1-5 are as follows: (1) Comparative Example 1-3 includes only one p-type doping layer, and the doping layer is the same as the first organic layer in Example 1-2 (the materials used and the doping rate are both the same). In Example 1-2, the EQE is improved by about 5% and the service life is improved by 43% compared to Comparative Example 1-3, and the driving voltages of both are equivalent. (2) Comparative Example 1-5 includes only one p-type doped layer, which is the same as the second organic layer in Example 1-2 (the materials and doping rates are the same). Example 1-2 has a 23% lower driving voltage and a 496% longer service life than Comparative Example 1-5. Although Example 1-2 has a lower EQE than Comparative Example 1-5, it achieves a high EQE of 27.4%, which is already a high efficiency level in the industry. Compared to Comparative Example 1-5, which has a high voltage and a very short service life, Example 1-2 is a device with better overall performance.

[0198] In Example 1-3, the first organic layer and the second organic layer are in contact with each other, the first organic layer is composed of the first p-type dopant compound 3-1 and HT-18, and the doping rate is 0.5%, and the second organic layer is composed of the second p-type dopant compound 3-1 and HT-18, and the doping rate is 3%. In Example 1-3, a low driving voltage of 3.2V, a high efficiency of 28.4% and a long service life of 250h are obtained. The results of comparing Example 1-3, Comparative Example 1-1 and Comparative Example 1-3 are as follows: (1) Comparative Example 1-1 contains only one p-type doping layer, and the doping layer is the same as the first organic layer in Example 1-3 (the materials used and the doping rate are both the same). In Example 1-3, the driving voltage is 0.4V lower than in Comparative Example 1-1, the service life is 79% longer, and the efficiency is lower than that of Comparative Example 1-1, but Example 1-3 achieves a high EQE level of 28.4%, and has advantages in overall performance such as low voltage and long service life. (2) Comparative Example 1-3 includes only one p-type doping layer, which is the same as the second organic layer in Example 1-3 (the materials and doping rates used are both the same). In Example 1-3, the EQE is improved by 8%, the service life is improved by 20%, and the driving voltage is equivalent, and the overall performance of Example 1-3 is greatly improved.

[0199] Similarly, compared to Comparative Example 1-5 having only the first organic layer, Examples 1-4 had a 1.1 V lower drive voltage, a 6-fold increase in service life, and a slightly lower EQE, but Examples 1-4 achieved a 27% higher EQE, which is already a high efficiency level in the industry, and the overall performance was greatly improved.

[0200] The service life of Examples 1-5 is improved by 53% and 7.3 times, respectively, compared to Comparative Examples 1-6 having only the first organic layer and Comparative Examples 1-4 having only the second organic layer. The driving voltage is lowered by 1.0V compared to Comparative Examples 1-4, and the EQE of Examples 1-5 is slightly lower, but Examples 1-5 achieve a higher EQE of 26.2%, which is already a high efficiency level in the industry, and the overall performance is greatly improved. The driving voltage is comparable to Comparative Examples 1-6, and the EQE is slightly improved.

[0201] In Examples 1-6, the service life was improved by 3.64 times compared to Comparative Example 1-5 having only the second organic layer, the driving voltage was reduced by 0.8 V, and the EQE of Examples 1-6 was slightly reduced. However, a high EQE of 28.5% was achieved, which is already a high efficiency level in the industry, and the overall performance was greatly improved.

[0202] From the above comparison, it has been found that an OLED having excellent overall performance can be obtained by using the first organic layer and the second organic layer having the specific conditions according to the present invention.

[0203] In Comparative Examples 1-7 to 1-9, a p-type dopant other than that of the present invention was used in the device, and in Comparative Example 1-9, a first organic layer and a second organic layer containing a p-type dopant other than that of the present invention were used, and in Comparative Examples 1-7 and 1-8, the second organic layer and the first organic layer in Comparative Example 1-9 were used, respectively. As can be seen from the data in Table 3, since the performance of the devices in Comparative Examples 1-7 to 1-9 is almost equivalent, it shows that the device in which a p-type dopant other than that of the present invention is applied to an organic layer containing a p-type dopant of multiple layers is not improved in performance compared to the device containing a single layer of p-type dopant. At the same time, when comparing Example 1-6 and Comparative Example 1-9, both contain a first organic layer and a second organic layer, but the p-type dopant used is different, and in Example 1-6, a p-type dopant compound 1-2 in the present invention was used, and in Comparative Example 1-9, PD1 other than that of the present invention was used as a p-type dopant. Examples 1-6 have better overall device performance, with a 78% increase in device life, a 10% increase in EQE, and a slight increase in drive voltage of 0.2 V. Therefore, Examples 1-6 show that the devices containing the specific p-type dopant and having the specific structure according to the present invention have better device performance.

[0204] Comparing Example 1-3 with Comparative Examples 1-10 and 1-11, the first organic layer or the second organic layer in Comparative Examples 1-10 and 1-11 is an organic layer containing only the p-type dopant compound 3-1 according to the present application, and is not an organic layer in which the p-type dopant according to the present application is doped into other organic materials. Example 1-3 has an improved EQE of 20% or more and an improved service life compared to Comparative Examples 1-10 and 1-11, but the driving voltage is slightly improved. As can be seen from this, Example 1-3 has better device performance.

[0205] As can be seen from the comparison and study of the above-mentioned Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-11, the device containing the specific p-type dopant according to the present invention and having the specific structure had superior device performance.

[0206] Example 2-1: A stacked organic electroluminescence device 400 according to the present invention shown in FIG. 4 was manufactured. (While the hole blocking layers 160a and 160b are omitted in this example, those skilled in the art can add hole blocking layers as necessary). The specific method is as follows. First, a glass substrate 101 having a pre-patterned indium tin oxide (ITO) anode 110 with a thickness of 1200 Å was washed with ultrapure water, and the ITO surface was treated with UV ozone and oxygen plasma. Then, the substrate was dried in a glove box filled with nitrogen gas to remove water, and then mounted on a holder and placed in a deposition chamber. Hereinafter, for the specified organic layer, a vacuum degree of about 1*10 -6In the case of 3000 Å, deposition was performed on the ITO anode in sequence by hot vacuum deposition at a rate of 0.01 to 10 Å / s. First, deposition was performed on the first light-emitting unit 1101. First, HT-18 and compound 3-1 were co-deposited to form the first organic layer 121a, in which the doping rate of compound 3-1 was 3%, and the thickness of the first organic layer 121a was 20 Å. Then, HT-18 and compound 1-2 were co-deposited on the first organic layer 121a to form the second organic layer 122a. In which the doping rate of compound 1-2 was 16%, and the thickness of the second organic layer 122a was 80 Å. Both the first organic layer 121a and the second organic layer 122a were used as the hole injection layer 220a of the first light-emitting unit 1101, and the total thickness was 100 Å. Then, the compound HT-18 is evaporated to be used as the hole transport layer (HTL) 130a, and the thickness of the hole transport layer (HTL) 130a is 400 Å. The compound EB is evaporated to be used as the electron blocking layer (EBL) 140a, and the thickness of the electron blocking layer (EBL) 140a is 50 Å. Next, the red light emitting dopant compound D-1 is doped into the host compound RH to form the red light emitting layer (EML) 150a. Among them, the doping rate of the compound D-1 is 3%, and the thickness of the red light emitting layer (EML) 150a is 400 Å. Then, the compounds ET and LiQ are evaporated to be used as the electron transport layer (ETL) 170a, and the thickness of the electron transport layer (ETL) 170a is 350 Å, and the doping rate of LiQ is 60%. Then, the charge generation layer 1102 was evaporated, and 15 Å of Yb metal was evaporated on the ETL to be used as the n-type charge generation layer 210, and then 30 Å of compound 1-2 was evaporated to be used as the p-type charge generation layer 310. Then, the second light-emitting unit 1103 was evaporated. HT-18 and compound 3-1 were co-evaporated to be used as the first organic layer 121b. Among them, the doping rate of compound 3-1 was 3%, and the thickness of the first organic layer 121b was 20 Å. Then, HT-18 and compound 1-2 were co-evaporated on the first organic layer 121b to be used as the second organic layer 122b. Among them, the doping rate of compound 1-2 was 16%, and the thickness of the second organic layer 122b was 80 Å.The first organic layer 121b and the second organic layer 122b are used together as the hole injection layer 220b of the second light-emitting unit 1103, and have a total thickness of 100 Å. Then, the compound HT-18 is evaporated to be used as the HTL 130b, and the thickness of the HTL 130b is 400 Å. The compound EB is evaporated to be used as the electron blocking layer (EBL) 140b, and the thickness of the EBL 140b is 50 Å. Then, the red light-emitting dopant compound D-1 is doped into the host compound RH to form the red light-emitting layer (EML) 150b, where the doping rate of the compound D-1 is 3%, and the thickness of the red light-emitting layer (EML) 150b is 400 Å. Then, the compound ET and LiQ were co-evaporated to form the electron transport layer (ETL) 170b, which had a thickness of 350 Å and a doping rate of LiQ of 60%. Finally, the compound EIL was evaporated to a thickness of 10 Å to form the electron injection layer (EIL) 180, and aluminum was evaporated to a thickness of 1200 Å to form the cathode 190.

[0207] It should be noted that the structure of the stacked element is merely exemplary and is not limited to that described in the present invention. For example, the hole injection layer 220a in the first light-emitting unit 1101 may have a different structure than that in the second light-emitting unit 1103. Furthermore, for example, the second light-emitting unit 1103 may have a different color host compound, light-emitting material, and a corresponding set of transport materials and element structures.

[0208] Comparative Example 2-1

[0209] The manufacturing process of Comparative Example 2-1 is the same as that of Example 2-1, except that the hole injection layer 220a of the first light-emitting unit and the hole injection layer 220b of the second light-emitting unit both contain only a first organic layer, both of which are composed of HT-18 and compound 3-1, the doping rate of compound 3-1 is 3%, and the thickness of the first organic layer is 100 Å.

[0210] Comparative Example 2-2

[0211] The manufacturing process of Comparative Example 2-2 is the same as that of Example 2-1, except that the hole injection layer 220a of the first light-emitting unit and the hole injection layer 220b of the second light-emitting unit both contain only the second organic layer, both of which are composed of HT-18 and compound 1-2, the doping rate of compound 1-2 is 16%, and the thickness of the second organic layer is 100 Å.

[0212] The details of the structures of some of the elements of Example 2-1 and Comparative Examples 2-1 to 2-2 are shown in Table 4. Layers using more than one material are obtained by doping different compounds in the weight ratios mentioned above.

[0213] [Table 4]

[0214] The performance of the elements in Example 2-1 and Comparative Examples 2-1 and 2-2 was measured. Among them, the color coordinate (CIE), voltage and external quantum efficiency (EQE) were 2 The device's service life was measured under the conditions of 80mA / cm 2 The time it takes for the light to decay to 97% of its initial brightness under these conditions is shown in Table 5.

[0215] [Table 5]

[0216] Example 2-1 is a stacked OLED in which two light-emitting units are connected by a charge generation layer. The first light-emitting unit and the second light-emitting unit each include a first organic layer and a second organic layer. The first organic layer is composed of HT-18 and compound 3-1, and the doping rate of compound 3-1 is 3%. The second organic layer is composed of HT-18 and compound 1-2, and the doping rate of compound 1-2 is 16%. Example 2-1 has a luminance of 2000 cd / m 2Under low voltage, it achieves a high EQE of 56.1%, a low voltage of 5.7V and an ultra-long service life of 250h. In Comparative Examples 2-1 and 2-2, the first light-emitting unit and the second light-emitting unit both only include the first organic layer or the second organic layer in Example 2-1 (the material and doping rate are the same). Example 2-1 has a service life improved by 14.6% and 58.2% compared to Comparative Examples 2-1 and 2-2, and the driving voltage is equivalent, and the EQE is improved by 10.8% compared to Comparative Example 2-1, and the efficiency is slightly lower by 4% compared to Comparative Example 2-2, but the improvement in service life is more significant.

[0217] As can be seen, the first organic layer and the second organic layer having a specific structure according to the present invention can similarly improve the overall performance of the laminated element.

[0218] Example 3-1

[0219] The organic electroluminescence device 300 shown in FIG. 3 was manufactured by the following specific method. First, a glass substrate 101 having an indium tin oxide (ITO) anode 110 with a thickness of 800 Å was cleaned and then treated with UV ozone and oxygen plasma. The substrate was then dried in a glove box filled with nitrogen gas to remove water. The substrate was then attached onto a substrate holder and placed in a vacuum chamber. The vacuum level was about 10. -8In the case of Torr, deposition was performed on the ITO anode in sequence by hot vacuum deposition at a rate of 0.01 to 10 Å / s. First, HT-18 and compound 3-1 were co-deposited and used as the first organic layer 120a. Among them, the doping rate of compound 3-1 was 3%, and the thickness of the first organic layer 120a was 20 Å. Then, HT-18 and compound 1-2 were co-deposited in the first organic layer 120a and used as the second organic layer 120b. Among them, the doping rate of compound 1-2 was 16%, and the thickness of the second organic layer 120b was 80 Å. Both the first organic layer 120a and the second organic layer 120b were used as the hole injection layer 120, and the total thickness was 100 Å. Then, compound HT-18 was deposited and used as the hole transport layer (HTL), and the thickness of the hole transport layer (HTL) was 250 Å. Compound HT-1 was used as an electron blocking layer (EBL), and the thickness of the electron blocking layer (EBL) was 50 Å. Then, blue light dopant compound D-2 was doped into blue light host compound BH, and co-deposited to be used as a blue light emitting layer (EML). Among them, the doping rate of compound D-2 was 4%, and the total thickness was 250 Å. Then, compound HB was deposited to be used as a hole blocking layer (HBL), and the thickness of the hole blocking layer (HBL) was 50 Å. On the HBL, compound ET1 and LiQ were co-deposited to be used as an electron transport layer (ETL), and the thickness of the electron transport layer (ETL) was 300 Å, and LiQ was 60% of the total weight of the ETL layer. On the ETL, 10 Å of LiQ was deposited to be used as an electron injection layer (EIL). Finally, 1200 Å of Al was deposited to be used as a cathode. The deposited device was transferred to a glove box and encapsulated with a glass cover to complete the device.

[0220] Comparative Example 3-1

[0221] The preparation method of Comparative Example 3-1 is consistent with Example 3-1, except that the hole injection layer 120 contains only the first organic layer, which is composed of HT-18 and compound 3-1, the compound 3-1 is 3% based on the total weight of the HIL, and the thickness of the hole injection layer 120 is 100 Å.

[0222] The structural details of some elements in Example 3-1 and Comparative Example 3-1 are shown in Table 6. Layers using more than one material are obtained by doping different compounds in the weight ratios mentioned above.

[0223] [Table 6]

[0224] The structure of the compound newly used in the device is shown below. [ka]

[0225] The performance of the elements in Example 3-1 and Comparative Example 3-1 was measured. Among them, the color coordinate (CIE), voltage and external quantum efficiency (EQE) were measured at a current density of 10 mA / cm 2 The device's service life (LT97) was measured under the conditions of 80mA / cm 2 This is the actual measured time for the luminance to decay to 97% of the initial luminance under driving at a constant current density of 1000 Hz. These data are shown in Table 7.

[0226] [Table 7]

[0227] Example 3-1 and Comparative Example 3-1 are blue fluorescent devices. The color coordinates of Example 3-1 and Comparative Example 3-1 shown in Table 7 are almost the same. Example 3-1 is a device using a structure including a first organic layer and a second organic layer in the present application. As can be seen from the comparison of the device data, the device driving voltage and EQE of Example 3-1 and Comparative Example 3-1 are almost equivalent, but the service life of Example 3-1 is significantly improved by 43%. It is shown that the organic electroluminescence device including the specific organic layer structure in the present application can improve the service life of the device and significantly improve the overall performance of the device.

[0228] As can be seen from the above data, the novel organic electroluminescent device comprising the specific p-type dopant and organic layer structure according to the present application can significantly improve the overall performance of the device, whether it is a single-layer device or a multilayer device.

[0229] It should be understood that the various embodiments described herein are merely illustrative and are not intended to limit the scope of the present invention. Thus, it will be apparent to those skilled in the art that the invention sought to be protected includes variations of the specific and preferred embodiments described herein. Many of the materials and structures described herein can be substituted with other materials and structures without departing from the concept of the present invention. It should be understood that the various theories as to why the present invention works are not limiting.

Claims

1. An organic electroluminescent element comprising an anode, a cathode, and an organic layer provided between the anode and the cathode, the organic layer includes a first organic layer and a second organic layer; the first organic layer comprises a first organic material and a first p-type dopant; the second organic layer comprises a second organic material and a second p-type dopant; the first organic layer contacts a second organic layer, and the second organic layer overlies the first organic layer; The organic electroluminescence element, wherein the first p-type dopant and the second p-type dopant have a structure represented by any one of the following formulas 14, 16, and 17: 【Chemistry 1】 (W is selected from O, X 1 , X 2 , X 3 and X 4 are each identically or differently selected from the group consisting of CR 3 ; R １ , R ２ is selected from a cyano group, R ３ are each identically or differently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a cyano group, or a combination thereof; At least one R ３ is selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a cyano group, and combinations thereof.

2. 2. The organic electroluminescence device according to claim 1, wherein the sum of the thicknesses of the first organic layer and the second organic layer is 100 nm or less.

3. 3. The organic electroluminescence device according to claim 2, wherein the sum of the thicknesses of the first organic layer and the second organic layer is 50 nm or less.

4. 3. The organic electroluminescence device according to claim 2, wherein the sum of the thicknesses of the first organic layer and the second organic layer is 20 nm or less.

5. The first organic material and the second organic material may be the same or different; 2. The organic electroluminescent device of claim 1, wherein the first p-type dopant and the second p-type dopant are the same.

6. 2. The organic electroluminescent device of claim 1, wherein the first organic material and the second organic material are the same or different, and the first p-type dopant and the second p-type dopant are different.

7. 2. The organic electroluminescence device according to claim 1, wherein the first p-type dopant and / or the second p-type dopant has a LUMO of −5.2 eV or more.

8. 8. The organic electroluminescence device according to claim 7, wherein the first p-type dopant and / or the second p-type dopant has a LUMO of −5.0 eV or more.

9. 8. The organic electroluminescence device according to claim 7, wherein the first p-type dopant and / or the second p-type dopant has a LUMO of −4.9 eV or more.

10. 2. The organic electroluminescent device of claim 1, wherein the LUMO energy level of the first p-type dopant is lower than or equal to the LUMO energy level of the second p-type dopant.

11. 2. The organic electroluminescent device of claim 1, wherein the LUMO energy level of the first p-type dopant is equal to or higher than the LUMO energy level of the second p-type dopant.

12. 2. The organic electroluminescence device according to claim 1, wherein the first organic material and / or the second organic material has a HOMO energy level of −4.5 eV or less.

13. 13. The organic electroluminescence device according to claim 12, wherein the first organic material and / or the second organic material has a HOMO energy level of −4.8 eV or less.

14. The organic electroluminescence device according to claim 1 , wherein the first organic material and / or the second organic material contains a monotriarylamine structural unit or a bistriarylamine structural unit.

15. The organic electroluminescence device according to claim 14, wherein the first organic material and / or the second organic material includes one or more chemical structural units selected from the group consisting of a monotriarylamine-carbazole structural unit, a monotriarylamine-thiophene structural unit, a monotriarylamine-furan structural unit, a monotriarylamine-fluorene structural unit, a bistriarylamine-carbazole structural unit, a bistriarylamine-thiophene structural unit, a bistriarylamine-furan structural unit, and a bistriarylamine-fluorene structural unit.

16. The organic electroluminescent device of claim 1 , wherein the first organic layer is in contact with an anode.

17. a third organic layer over the second organic layer, the third organic layer comprising a third organic material and a third p-type dopant; the third organic material and the first organic material and / or the second organic material are the same or different; 17. The organic electroluminescent device according to claim 1 or 16, wherein the third p-type dopant and the first p-type dopant and / or the second p-type dopant are the same or different.

18. 2. The organic electroluminescent device according to claim 1, further comprising at least one light-emitting layer provided between the second organic layer and the cathode.

19. The organic electroluminescence device according to claim 18 , wherein the light-emitting layer contains a light-emitting material which is a phosphorescent, fluorescent or delayed fluorescent material.

20. further comprising a fourth organic layer disposed between the second organic layer and the light-emitting layer; The organic electroluminescence device according to claim 18 , wherein the fourth organic layer contains a fourth organic material.

21. The organic electroluminescence device according to claim 20 , wherein the fourth organic material is the same as or different from the first organic material or the second organic material.

22. 2. The organic electroluminescence device according to claim 1, further comprising a charge generating layer including a p-type charge generating layer provided between the light emitting layer and the cathode.

23. 23. The organic electroluminescence device according to claim 22, wherein the p-charge generating layer of the charge generating layer contains a first p-type dopant or a second p-type dopant.

24. 23. The organic electroluminescent device of claim 22, wherein the first organic layer or the second organic layer is in contact with a p-charge generating layer of the charge generating layer.

25. An electronic assembly comprising the organic electroluminescent device according to claim 1 .

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