An organic electroluminescent device

Abstract

The application discloses an organic electroluminescent device. The organic electroluminescent device comprises an anode, a cathode, a light-emitting layer arranged between the cathode and the anode, an electron transport layer arranged between the cathode and the light-emitting layer, and an electron blocking layer arranged between the anode and the light-emitting layer; wherein the electron transport layer comprises a first compound, the electron blocking layer comprises a second compound, and the light-emitting layer comprises the first compound and the second compound, wherein the first compound has a structure represented by formula 1. The specific organic layer of the electroluminescent device can save material types, reduce the influence of interface generation, and comprehensively improve the voltage, current efficiency, power efficiency, external quantum efficiency and life performance of the device.

Description

Technical Field

[0001] This invention relates to an organic electroluminescent device. More particularly, it relates to an organic electroluminescent device comprising a first compound of formula 1 and having a specific device structure. Background Technology

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

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a bilayer organic electroluminescent device comprising an arylamine hole transport layer and a tri-8-hydroxyquinoline-aluminum layer as both an electron transport and luminescent layer (Applied Physics Letters, 1987, 51(12): 913-915). Once a bias voltage was applied to the device, green light was emitted. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). State-of-the-art OLEDs can include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more luminescent layers between the cathode and anode. Because OLEDs are self-emissive solid-state devices, they offer enormous potential for display and lighting applications. Furthermore, the inherent properties of organic materials, such as their flexibility, make them well-suited for specialized applications, such as in the fabrication of flexible substrates.

[0004] OLEDs can be categorized into three different types based on their light-emitting mechanism. The OLED invented by Tang and van Slyke is a fluorescent OLED. It uses only singlet state emission. The triplet state generated in the device is wasted through non-radiative decay channels. Therefore, the internal quantum efficiency (IQE) of fluorescent OLEDs is only 25%. This limitation hindered the commercialization of OLEDs. In 1997, Forrest and Thompson reported phosphorescent OLEDs, which use triplet emission from complexed heavy metals as the emitter. Therefore, both singlet and triplet states can be harvested, achieving 100% IQE. Due to its high efficiency, the discovery and development of phosphorescent OLEDs directly contributed to the commercialization of active-matrix OLEDs (AMOLEDs). More recently, Adachi achieved high efficiency through thermally activated delayed fluorescence (TADF) of organic compounds. These emitters have small singlet-triple state gaps, making it possible for excitons to return from the triplet state to the singlet state. In TADF devices, triplet excitons can generate singlet excitons through reverse intersystem crossing, resulting in high IQE.

[0005] OLEDs can also be classified into small-molecule OLEDs and polymer OLEDs based on the form of the materials used. Small molecules refer to any organic or organometallic material that is not a polymer. Small molecules can have large molecular weights, provided they have a precise structure. Dendritic polymers with well-defined structures are considered small molecules. Polymer OLEDs include conjugated polymers and non-conjugated polymers with side-chain luminescent groups. Small-molecule OLEDs can become polymer OLEDs if post-polymerization occurs during manufacturing.

[0006] Various OLED manufacturing methods exist. Small molecule OLEDs are typically manufactured via vacuum thermal evaporation. Polymer OLEDs are manufactured using solution methods, such as spin coating, inkjet printing, and nozzle printing. Small molecule OLEDs can also be manufactured using solution methods if the material can be dissolved or dispersed in a solvent.

[0007] The emission color of OLEDs can be achieved through the design of the luminescent material structure. OLEDs can include one or more luminescent layers to achieve the desired spectrum. Green, yellow, and red OLEDs using phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still suffer from issues such as blue unsaturation, short device lifetime, and high operating voltage. Commercial full-color OLED displays typically employ a hybrid strategy, using blue fluorescence and phosphorescent yellow, or red and green. Currently, the rapid decrease in efficiency of phosphorescent OLEDs at high brightness remains a problem. Furthermore, a more saturated emission spectrum, higher efficiency, and longer device lifetime are desired.

[0008] Organic light-emitting diodes (OLEDs) convert electrical energy into light by applying a voltage across their terminals. Typically, an OLED comprises an anode, a cathode, and an organic layer between the anode and cathode. This organic layer includes a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), and an emissive layer (EML, comprising a host material and doped materials), where the hole blocking layer is an optional functional layer. Depending on their function, the materials comprising the organic layer can be categorized as hole injection materials, hole transport materials, electron blocking materials, host materials, emissive materials, hole blocking materials, electron transport materials, and electron injection materials. When a bias voltage is applied to the device, holes are injected from the anode into the emissive layer, and electrons are injected from the cathode into the emissive layer. Holes and electrons meet in the emissive layer to form excitons, which recombine to emit light. In organic thin films, the electron mobility is generally much lower than the hole mobility. This leads to the accumulation of excessive holes in the light-emitting layer, which in turn causes the formation of non-luminescent positive ion compounds, resulting in reduced device brightness and lifetime. To achieve a better carrier balance, in addition to the electron transport material, another molecule is typically introduced into the electron transport layer to improve the electron transport characteristics of the device. These include, but are not limited to, LiQ, LiF, and CsF, or may include some n-type conductive doped materials, including but not limited to TTN and BEDT-TTF, or some highly active metals, including but not limited to Li, Cs, Mg, and Ca.

[0009] Electron blocking and electron transport layers are crucial functional layers affecting the performance of organic light-emitting diodes (OLEDs). The selection and combination of their materials significantly influence the driving voltage, efficiency, and lifetime of OLEDs. Commercially, obtaining OLEDs with low driving voltage, high efficiency, and long lifespan necessitates the development of novel electron blocking and electron transport materials, and the selection of appropriate material combinations is equally important for achieving these goals.

[0010] CN111527083A discloses an organic light-emitting device comprising a first host compound and a second host compound, wherein the structure of the first host compound is as follows: The structure of the second main compound is as follows: This application discloses the effects of triazine compounds and bicarbazole compounds on device performance when used only as a combination of dual host materials, but does not disclose or teach the effects of triazine compounds as both host materials and electron transport materials, or bicarbazole compounds as both host materials and electron blocking materials, on device performance.

[0011] US2020377489A1 discloses an organic light-emitting device comprising a first host compound and a second host compound, wherein the structure of the first host compound is as follows: The structure of the second main compound is as follows: This application discloses the effects of triazine compounds and bicarbazole compounds on device performance when used only as a combination of dual host materials, but does not disclose or teach the effects of triazine compounds as both host materials and electron transport materials, or bicarbazole compounds as both host materials and electron blocking materials, on device performance.

[0012] In an OLED device, interface issues such as energy levels and / or molecular alignment may exist between different organic layers, which can affect device performance. Our research found that when the EBL and ETL are made of one or more of the same materials as the EML, the impact of the interface can be reduced while simultaneously improving device performance. Furthermore, reducing the number of material types used can lower material costs and achieve greater economic benefits. However, currently commercially available structures typically use more than 12 types of organic materials, especially green light, which generally employs a dual-substrate structure. Therefore, in organic electroluminescent devices, device structures using fewer material types and with lower interface influence near the EML are particularly important. Summary of the Invention

[0013] The present invention aims to provide an organic electroluminescent device comprising a first compound of Formula 1 and having a specific device structure to solve at least some of the aforementioned problems. The organic electroluminescent device can save on material types, reduce the impact of interface formation, and provide better device performance, such as lower voltage and increased lifetime.

[0014] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0015] cathode,

[0016] anode,

[0017] A light-emitting layer disposed between the cathode and the anode, an electron transport layer disposed between the cathode and the light-emitting layer, and an electron blocking layer disposed between the anode and the light-emitting layer;

[0018] The electron transport layer comprises a first compound, the electron blocking layer comprises a second compound, and the light-emitting layer comprises the first compound and the second compound;

[0019] The first compound has the structure represented by Formula 1:

[0020]

[0021] Where Z is selected from O, S, or Se;

[0022] A1-A7 are selected from CR each time they appear, either identically or differently. x Or N;

[0023] R x Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0024] Ar, each time it appears, is selected from the same or different aryl groups with 6-30 carbon atoms (substituted or unsubstituted), heteroaryl groups with 3-30 carbon atoms (substituted or unsubstituted), or combinations thereof.

[0025] This invention discloses an organic electroluminescent device with a specific device structure. The light-emitting layer of the organic electroluminescent device contains two compounds, namely a first compound with a general structure of Formula 1 used in the electron transport layer and a second compound used in the hole transport layer. In particular, the first compound with a general structure of Formula 1 can be used as both a host material and an electron transport material. This specific combination can reduce the defects formed at the interface of different materials, thereby reducing the voltage and increasing the lifespan. At the same time, reducing the types of materials used can reduce material costs and obtain more economic benefits. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an organic light-emitting device that may contain the compounds and combinations of compounds disclosed herein.

[0027] Figure 2 This is a schematic diagram of another organic light-emitting device that may contain compounds and combinations of compounds disclosed herein. Detailed Implementation

[0028] OLEDs can be manufactured on various substrates, such as glass, plastic, and metal. Figure 1 An organic light-emitting device 100 is illustrated schematically and non-limitingly. 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, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode 190. Device 100 can be fabricated by sequentially depositing the described layers. The figures are not necessarily drawn to scale, and some layer structures may be omitted as needed, such as the hole blocking layer 160. The properties and functions of each layer, as well as exemplary materials, are described in more detail in columns 6-10 of U.S. Patent 7,279,704B2, the entire contents of which are incorporated herein by reference.

[0029] Each of these layers has numerous examples. For instance, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, 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 50:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. An example of a host material is disclosed in U.S. Patent No. 6,303,238 to Thompson et al., 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, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of cathodes are disclosed in U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entirety. These cathodes comprise composite cathodes having a thin metal layer, such as Mg:Ag, overlaid with a transparent, conductive, sputter-deposited ITO layer. The principles and use of barrier 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 also incorporated herein by reference in their entirety. Examples of implantation layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is also incorporated herein by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is also incorporated herein by reference in its entirety.

[0030] The layered structure described above is provided through non-limiting embodiments. The functionality of an OLED can be achieved by combining the various layers described above, or some layers can be omitted entirely. It may also 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 functional layer may include several sublayers. For example, a light-emitting layer may have two different light-emitting materials to achieve a desired emission spectrum.

[0031] The term "OLED device" includes an anode layer, a cathode layer, and one or more organic layers disposed between the anode layer and the cathode layer. An "OLED device" can be bottom-emitting, that is, emitting light from the substrate side, or top-emitting, that is, emitting light from the encapsulation layer side, or a transparent device, that is, emitting light from both the substrate and encapsulation sides.

[0032] The term "electron transport layer" refers to an organic layer containing materials with electron transport properties and materials used to enhance these properties. Materials enhancing electron transport properties include, but are not limited to, LiQ, LiF, and CsF, or may include n-type conductive doped materials, including but not limited to TTN and BEDT-TTF, and may also include highly active metals, including but not limited to Li, Cs, Mg, and Ca. The electron transport layer is typically located between the light-emitting layer and the cathode, and its thickness is generally 30-50 nm. Sometimes a hole-blocking layer, typically 5-10 nm thick and undoped, can be added between the electron transport layer and the light-emitting layer; similarly, an electron injection layer, typically less than 5 nm thick and undoped, can be added between the electron transport layer and the cathode.

[0033] In one embodiment, an OLED can be described as having an "organic layer" disposed between a cathode and an anode. This organic layer may include one or more layers.

[0034] OLEDs also require an encapsulation layer, such as Figure 2 An organic light-emitting device 200 is shown schematically and non-limitingly, which is related to... Figure 1 The difference lies in the fact that an encapsulation layer 102 may also be included above the cathode 190 to protect against harmful substances from the environment, such as moisture and oxygen. The "encapsulation layer" can be a thin-film encapsulation with a thickness of less than 100 micrometers, comprising one or more thin films directly deposited onto the device, or it can be a cover glass adhered to a substrate. Any material capable of providing encapsulation can be used as the encapsulation layer, such as glass or an organic-inorganic hybrid layer. The encapsulation layer should be placed directly or indirectly on the outside of the OLED device. Multilayer thin-film encapsulation is described in U.S. Patent 7,968,146B2, the entire contents of which are incorporated herein by reference.

[0035] Devices manufactured according to embodiments of the present invention can be incorporated into a variety of consumer products having one or more electronic component modules (or units). Some examples of such consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, head-up displays, fully or partially transparent displays, flexible displays, smartphones, tablet computers, phablets, wearable devices, smartwatches, laptop computers, digital cameras, portable camcorders, viewfinders, microdisplays, 3D displays, vehicle displays, and taillights.

[0036] The materials and structures described in this article can also be used in other organic electronic devices listed above.

[0037] As used herein, "top" means furthest from the substrate, and "bottom" means closest to the substrate. When the first layer is described as being "disposed" on the second layer, the first layer is positioned further from the substrate. Unless it is specified that the first layer "contacts" the second layer, other layers may exist between the first and second layers. For example, even if various organic layers exist between the cathode and anode, the cathode may still be described as being "disposed" on the anode.

[0038] As used herein, “solution-handleable” means capable of being dissolved, dispersed or transported in and / or deposited from a liquid medium in the form of a solution or suspension.

[0039] When a ligand is believed to directly contribute to the photosensitivity of the emitting material, the ligand can be called "photosensitive." When a ligand is believed not to contribute to the photosensitivity of the emitting material, the ligand can be called "auxiliary," but auxiliary ligands can alter the properties of photosensitivity ligands.

[0040] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistical limit through delayed fluorescence. Delayed fluorescence can generally be divided into two types: P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0041] On the other hand, E-type delayed fluorescence does not depend on the collision of two triplet states, but rather on the transition between triplet and singlet excited states. Compounds capable of producing E-type delayed fluorescence need to have a very small singlet-triple gap to facilitate the transition between energy states. Thermal energy can activate the transition from triplet to singlet. This type of delayed fluorescence is also called thermally activated delayed fluorescence (TADF). A significant characteristic of TADF is that the delayed component increases with increasing temperature. If the reverse system crossover (RISC) rate is fast enough to minimize the nonradiative decay from the triplet state, the fraction of singlet excited states that are refilled can reach 75%. The total singlet fraction can be 100%, far exceeding the 25% spin statistics of electrogenerated excitons.

[0042] E-type delayed fluorescence can be observed in excited complex systems or single compounds. Unbound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triple bandgap (ΔE). S-T Organic, nonmetallic donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized as donor-acceptor charge transfer (CT) emission. Spatial separation of the HOMO and LUMO in these donor-acceptor compounds usually produces small ΔE. S-T These states can include CT states. Typically, donor-acceptor luminescent materials are constructed by linking an electron donor moiety (e.g., an amino or carbazole derivative) with an electron acceptor moiety (e.g., an N-containing six-membered aromatic ring).

[0043] Definition of the term "substituent group"

[0044] Halogens or halides—as used herein—include fluorine, chlorine, bromine, and iodine.

[0045] Alkyl – as used herein, includes straight-chain and branched alkyl groups. An alkyl group can be an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group 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-pentadecanyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, and 3-methylpentyl. Among the above, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, and n-hexyl are preferred. Additionally, the alkyl group may optionally be substituted.

[0046] Cycloalkyl – as used herein, comprises cyclic alkyl groups. The cycloalkyl group can be a cycloalkyl group having 3 to 20 carbon atoms, preferably a cycloalkyl group having 4 to 10 carbon atoms. Examples of cycloalkyl groups include cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl, etc. Among the above, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, and 4,4-dimethylcyclohexyl are preferred. Furthermore, the cycloalkyl group may optionally be substituted.

[0047] Heteroalkyl – as used herein, a heteroalkyl group comprises one or more carbon atoms in an alkyl chain that are replaced by heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, selenium, phosphorus, silicon, germanium, and boron atoms. The heteroalkyl group can 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. Examples of heteroalkyl groups include methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermanylmethyl, trimethylgermanylethyl, trimethylgermanylisopropyl, dimethylethylgermanylmethyl, dimethylisopropylgermanylmethyl, tert-butyldimethylgermanylmethyl, triethylgermanylmethyl, triethylgermanylethyl, triisopropylgermanylmethyl, triisopropylgermanylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl, triisopropylsilylethyl. Additionally, heteroalkyl groups may optionally be substituted.

[0048] Alkenyl – as used herein, encompasses straight-chain, branched, and cyclic olefinic groups. An alkenyl group can be an alkenyl group containing 2 to 20 carbon atoms, preferably an alkenyl group having 2 to 10 carbon atoms. Examples of alkenyl groups include vinyl, propenyl, 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, cyclohepttrienyl, cyclooctenyl, cyclooctatetraenyl, and norbornyl. In addition, the alkenyl group can be optionally substituted.

[0049] Alkynyl – as used herein, encompasses straight-chain alkynyl groups. An alkynyl group can be one containing 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms. Examples of alkynyl groups include ethynyl, propynyl, propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3,3-dimethyl-1-butynyl, 3-ethyl-3-methyl-1-pentynyl, 3,3-diisopropyl-1-pentynyl, phenylethynyl, phenylpropynyl, etc. Among the above, ethynyl, propynyl, propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, and phenylethynyl are preferred. Furthermore, the alkynyl group may be optionally substituted.

[0050] Aryl or aromatic group – as used herein, both non-fused and fused systems are considered. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, fenene, fluorene, pyrene, etc. Perylene and azulene, 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-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methyldiphenyl, 4”-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesitylene, and m-tetraphenyl. Additionally, the aryl group may optionally be substituted.

[0051] Heterocyclic groups or heterocycles – as used herein, consider non-aromatic cyclic groups. Non-aromatic heterocyclic groups include saturated heterocyclic groups having 3-20 ring atoms and unsaturated non-aromatic heterocyclic groups having 3-20 ring atoms, wherein at least one ring atom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron atoms. Preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms, including at least one heteroatom such as nitrogen, oxygen, silicon, or sulfur. Examples of non-aromatic heterocyclic groups include ethylene oxide, oxetane, tetrahydrofuranyl, tetrahydropyranyl, dioxopentacyclic, dioxahexacyclic, acridineyl, dihydropyrroleyl, tetrahydropyrroleyl, piperidinyl, oxazolidinyl, morpholinyl, piperazineyl, oxetane-heptanetrienyl, thioheptanetrienyl, azirane-heptanetrienyl, and tetrahydrothiorroleyl. In addition, the heterocyclic group can be optionally substituted.

[0052] Heteroaryl – as used herein – can be a non-fused or fused heteroaryl group comprising 1 to 5 heteroatoms, wherein at least one heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron. Isoaryl also refers to heteroaryl. Heteroaryl can be a heteroaryl having 3 to 30 carbon atoms, preferably a heteroaryl having 3 to 20 carbon atoms, and more preferably a heteroaryl having 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolecarbazole, pyridineindole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxtriazole, dioxazole, thiadiazol, pyridine, pyrazine, pyrazine, triazine, oxazine, oxthiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzoisoxazole, benzothiazole, quinoline, isoquinoline Phosphine, cyclophosphine, quinazoline, quinoxaline, naphthidine, phthalazine, pteridine, xanthan, acridine, phenazine, phenothiazine, benzofuranopyridine, furanodipyridine, benzothiophenopyridine, thiophenodipyridine, benzoselenophenopyridine, selenobenzodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborane, 1,3-azaborane, 1,4-azaborane, boronazole and its aza analogues. Additionally, the heteroaryl group may optionally be substituted.

[0053] Alkoxy groups—as used herein—are represented by -O-alkyl, -O-cycloalkyl, -O-heteroalkyl, or -O-heterocyclic groups. Examples and preferred examples of alkyl, cycloalkyl, heteroalkyl, and heterocyclic groups are the same as described above. An alkoxy group can be an alkoxy group having 1 to 20 carbon atoms, preferably an alkoxy group having 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, cyclopropyloxy, cyclobutyloxy, cyclopentoxy, cyclohexyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy, and ethoxymethyloxy. Additionally, alkoxy groups may optionally be substituted.

[0054] Aryloxy group – as used herein, is represented by -O-aryl or -O-heteroaryl. Examples and preferred examples of aryl and heteroaryl groups are the same as described above. The aryloxy group can be an aryloxy group having 6 to 30 carbon atoms, preferably an aryloxy group having 6 to 20 carbon atoms. Examples of aryloxy groups include phenoxy and biphenyloxy groups. Additionally, the aryloxy group may optionally be substituted.

[0055] Arylalkyl – as used herein, encompasses aryl-substituted alkyl groups. An arylalkyl group can be an arylalkyl group having 7 to 30 carbon atoms, preferably an arylalkyl group having 7 to 20 carbon atoms, and more preferably an arylalkyl group having 7 to 13 carbon atoms. Examples of arylalkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl tert-butyl, α-naphthylmethyl, 1-α-naphthyl-ethyl, 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 The compounds include alkyl groups, such as o-methylbenzyl, p-chlorobenzyl, m-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 the above, benzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, and 2-phenylisopropyl are preferred. Additionally, the alkyl group may optionally be substituted.

[0056] Alkylsilyl – as used herein, encompasses alkyl-substituted silyl groups. The alkylsilyl group can be an alkylsilyl group having 3 to 20 carbon atoms, preferably an alkylsilyl group having 3 to 10 carbon atoms. Examples of alkylsilyl groups include trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tritert-butylsilyl, triisobutylsilyl, dimethyltert-butylsilyl, and methylditert-butylsilyl. Furthermore, the alkylsilyl group may optionally be substituted.

[0057] Arylsilane – as used herein, encompasses at least one aryl-substituted silane group. The arylsilane can be an arylsilane having 6 to 30 carbon atoms, preferably an arylsilane having 8 to 20 carbon atoms. Examples of arylsilanes include triphenylsilyl, phenyldiphenylsilyl, diphenylbiphenylsilyl, phenyldiethylsilyl, diphenylethylsilyl, phenyldimethylsilyl, diphenylmethylsilyl, phenyldiisopropylsilyl, diphenylisopropylsilyl, diphenylbutylsilyl, diphenylisobutylsilyl, and diphenyltert-butylsilyl. Additionally, the arylsilane may optionally be substituted.

[0058] Alkylgermanium group – as used herein, encompasses alkyl-substituted germanium groups. The alkylgermanium group can be an alkylgermanium group having 3 to 20 carbon atoms, preferably an alkylgermanium group having 3 to 10 carbon atoms. Examples of alkylgermanium groups include trimethylgermanium, triethylgermanium, methyldiethylgermanium, ethyldimethylgermanium, tripropylgermanium, tributylgermanium, triisopropylgermanium, methyldiisopropylgermanium, dimethylisopropylgermanium, tritert-butylgermanium, triisobutylgermanium, dimethyltert-butylgermanium, and methylditert-butylgermanium. Furthermore, the alkylgermanium group may optionally be substituted.

[0059] Arylgermanium – as used herein, encompasses a germanium group substituted with at least one aryl or heteroaryl group. The arylgermanium group can be an arylgermanium group having 6 to 30 carbon atoms, preferably an arylgermanium group having 8 to 20 carbon atoms. Examples of arylgermanium groups include triphenylgermanium, phenyldiphenylgermanium, diphenylbiphenylgermanium, phenyldiethylgermanium, diphenylethylgermanium, phenyldimethylgermanium, diphenylmethylgermanium, phenyldiisopropylgermanium, diphenylisopropylgermanium, diphenylbutylgermanium, diphenylisobutylgermanium, and diphenyltert-butylgermanium. Additionally, the arylgermanium group may optionally be substituted.

[0060] The term "aza" in azadibenzofuran, azadibenzothiophene, etc., refers to the substitution of one or more CH groups in the corresponding aromatic segment by a nitrogen atom. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline, and other analogs having two or more nitrogen atoms in the ring system. Other nitrogen analogs of the aforementioned aza derivatives will readily conceive of those skilled in the art, and all such analogs are identified as being included in the terminology used herein.

[0061] In this disclosure, unless otherwise defined, the term "substituted alkyl", "substituted cycloalkyl", "substituted heteroalkyl", "substituted heterocyclic", "substituted aralkyl", "substituted alkoxy", "substituted aryl", "substituted alkenyl", "substituted alkynyl", "substituted heteroaryl", "substituted alkylsilyl", "substituted arylsilyl", "substituted alkylgermanium", "substituted arylgermanium", "substituted amino", "substituted acyl", "substituted carbonyl", and "substituted carboxylic acid" are used interchangeably. The substituted ester group, substituted sulfinyl group, substituted sulfonyl group, substituted phosphinyl group refers to any one of the following groups: alkyl, cycloalkyl, heteroalkyl, heterocyclic, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermanium, arylgermanium, amino, acyl, carbonyl, carboxylic acid, ester, sulfinyl, sulfonyl, and phosphinyl groups. One or more groups can be selected from deuterium, halogen, unsubstituted alkyl groups having 1-20 carbon atoms. Cycloalkyl groups having 3-20 carbon atoms, unsubstituted heteroalkyl groups having 1-20 carbon atoms, unsubstituted heterocyclic groups having 3-20 carbon atoms, unsubstituted aralkyl groups having 7-30 carbon atoms, unsubstituted alkoxy groups having 1-20 carbon atoms, unsubstituted aryloxy groups having 6-30 carbon atoms, unsubstituted alkenyl groups having 2-20 carbon atoms, unsubstituted alkynyl groups having 2-20 carbon atoms, and unsubstituted alkyne groups having 6-30 carbon atoms. Aryl, unsubstituted heteroaryl with 3-30 carbon atoms, unsubstituted alkylsilyl with 3-20 carbon atoms, unsubstituted arylsilyl with 6-20 carbon atoms, unsubstituted alkylgermanium with 3-20 carbon atoms, unsubstituted arylgermanium with 6-20 carbon atoms, unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphine, and combinations thereof with 0-20 carbon atoms.

[0062] It should be understood that when a molecular segment is described as a substituent or otherwise attached to another part, its name may be written according to whether it is a segment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or attaching segments are considered equivalent.

[0063] In the compounds mentioned in this disclosure, hydrogen atoms can be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen can also be replaced by their other stable isotopes. Substitution with other stable isotopes in the compounds is likely preferred due to their ability to enhance device efficiency and stability.

[0064] In the compounds mentioned in this disclosure, multiple substitution refers to the range including disubstitution, up to the maximum number of available substitutions. When a substituent in a compound mentioned in this disclosure represents multiple substitution (including disubstitution, trisubstitution, tetrasubstitution, etc.), it means that the substituent can be present at multiple available substitution positions on its linkage structure. The substituent present at multiple available substitution positions can be the same structure or different structures.

[0065] In the compounds mentioned in this disclosure, unless explicitly specified, for example, that adjacent substituents can optionally connect to form a ring, adjacent substituents in the compounds cannot connect to form a ring. In the compounds mentioned in this disclosure, the optional connection of adjacent substituents to form a ring includes both cases where adjacent substituents can connect to form a ring and cases where adjacent substituents do not connect to form a ring. When adjacent substituents can optionally connect to form a ring, the formed ring can be a monocyclic or polycyclic ring (including spirocyclic, bridged, fused rings, etc.), as well as an alicyclic, heterocyclic, aromatic, or heteroaromatic ring. In this context, adjacent substituents can 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 away. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0066] The statement that adjacent substituents can optionally connect to form a ring is also intended to be understood as referring to two substituents bonded to the same carbon atom connecting to each other via chemical bonds to form a ring, as exemplified by the following formula:

[0067]

[0068] The statement that adjacent substituents can optionally link to form a ring is also intended to be understood as referring to two substituents bonded to carbon atoms directly bonded to each other forming a ring through chemical bonds, as exemplified by the following formula:

[0069]

[0070] The statement that adjacent substituents can optionally connect to form a ring is also intended to be understood as referring to two substituents bonded to a further distant carbon atom connecting to each other by chemical bonds to form a ring, which can be exemplified by the following formula:

[0071]

[0072] Furthermore, the statement that adjacent substituents can optionally connect to form a ring is also intended to mean that, in the case where one of the two adjacent substituents represents hydrogen, the second substituent bonds to the position where the hydrogen atom is bonded, thereby forming a ring. This is illustrated by the following example:

[0073]

[0074] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising at least:

[0075] cathode,

[0076] anode,

[0077] A light-emitting layer disposed between the cathode and the anode, an electron transport layer disposed between the cathode and the light-emitting layer, and an electron blocking layer disposed between the anode and the light-emitting layer;

[0078] The electron transport layer comprises a first compound, the electron blocking layer comprises a second compound, and the light-emitting layer comprises the first compound and the second compound;

[0079] The first compound has the structure represented by Formula 1:

[0080]

[0081] Where Z is selected from O, S, or Se;

[0082] A1-A7 are selected from CR each time they appear, either identically or differently. x Or N;

[0083] R x Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0084] Ar, each time it appears, is selected from the same or different aryl groups with 6-30 carbon atoms (substituted or unsubstituted), heteroaryl groups with 3-30 carbon atoms (substituted or unsubstituted), or combinations thereof.

[0085] In this embodiment, the "first compound" in the light-emitting layer refers to a compound having the same chemical structure as the first compound contained in the aforementioned electron transport layer, or a deuterated variant of the first compound contained in the aforementioned electron transport layer. Similarly, the "second compound" in the light-emitting layer refers to a compound having the same chemical structure as the second compound contained in the aforementioned electron blocking layer, or a deuterated variant of the second compound contained in the aforementioned electron blocking layer. The deuterated variant refers to a compound obtained by partially or completely replacing the hydrogen in the compound with deuterium.

[0086] In this embodiment, the first compound has the property of transporting electrons in the electron transport layer, and the second compound has the property of transporting holes in the electron blocking layer.

[0087] According to one embodiment of the present invention, A1-A7 are selected from CR each time they appear, either identically or differently. x ;where R x Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 cyclic 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.

[0088] According to one embodiment of the present invention, at least one of A1-A7 is selected from CR. x And the R x Choose from the following groups: substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, and combinations thereof.

[0089] According to one embodiment of the present invention, at least one of A1-A7 is selected from CR. x And the R x Choose from the following groups: phenyl, deuterated phenyl, naphthyl, biphenyl, phenanthrene, terphenyl, triphenylene, deuterated naphthyl, deuterated biphenyl, deuterated phenanthrene, deuterated terphenyl, deuterated triphenylene, and combinations thereof.

[0090] According to one embodiment of the present invention, the first compound has a structure represented by formula 1-a:

[0091]

[0092] in,

[0093] Z is selected from O, S, or Se;

[0094] A1-A6 are selected from CR each time they appear, either identically or differently.x Or N;

[0095] R y R z Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted.

[0096] R x R y and R z Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0097] R y and R z At least one of them is an aryl group with 6-30 carbon atoms, either substituted or unsubstituted;

[0098] Ar is selected, either identically or differently, from substituted or unsubstituted aryl groups having 10-30 carbon atoms.

[0099] According to one embodiment of the present invention, Z is selected from O or S.

[0100] According to one embodiment of the present invention, Z is O.

[0101] According to one embodiment of the present invention, wherein A1-A6 are selected from CR each time they appear, either identically or differently. x .

[0102] According to one embodiment of the present invention, at least one of A1-A6 is selected from N, for example, one or two are selected from N.

[0103] According to one embodiment of the present invention, wherein the R xEach time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 cyclic 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.

[0104] According to one embodiment of the present invention, wherein the R x Each time it appears, it is selected from the group consisting of the following, either the same or different: hydrogen, deuterium, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, and combinations thereof.

[0105] According to one embodiment of the present invention, wherein the R y and R z At least one of them is a substituted or unsubstituted aryl group having 6-20 carbon atoms; the remaining R y and R z Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted aryl groups having 6-20 carbon atoms, and combinations thereof.

[0106] According to one embodiment of the present invention, R y and R z At least one is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorene, and combinations thereof; the remaining R y and R z Each time it appears, it is selected from the same or different groups of the following: hydrogen, deuterium, substituted or unsubstituted aryl groups having 6-20 carbon atoms, and combinations thereof.

[0107] According to one embodiment of the invention, the Ar is selected, in the same or different ways, each time it appears, from a substituted or unsubstituted aryl group having 10-30 carbon atoms. When the Ar is selected from a substituted aryl group having 10-30 carbon atoms, the substitution is selected from the group consisting of: deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof.

[0108] According to one embodiment of the invention, the Ar is selected, in the same or different ways, each time it appears, from a substituted or unsubstituted aryl group having 10-20 carbon atoms. When the Ar is selected from a substituted aryl group having 10-20 carbon atoms, the substitution is selected from the group consisting of: deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 cyclic carbon atoms, substituted or unsubstituted aryl groups having 6-18 carbon atoms, and combinations thereof.

[0109] According to one embodiment of the present invention, wherein the Ar is selected from the group consisting of naphthyl, biphenyl, phenanthryl, terphenyl, triphenylene, deuterated naphthyl, deuterated biphenyl, deuterated phenanthryl, deuterated terphenyl, deuterated triphenylene, and combinations thereof, each time it appears.

[0110] According to one embodiment of the present invention, the first compound is selected from the group consisting of compounds A-1 to A-138, the specific structures of which are given in claim 6.

[0111] According to one embodiment of the present invention, the hydrogen in compounds A-1 to A-138 can be partially or completely replaced by deuterium.

[0112] According to one embodiment of the present invention, the second compound has a structure represented by Formula 2:

[0113]

[0114] in,

[0115] L x Each time it appears, it is selected from single bonds, substituted or unsubstituted alkylene groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkylene groups having 3-20 carbon atoms, substituted or unsubstituted arylene groups having 6-30 carbon atoms, substituted or unsubstituted heteroarylene groups having 3-30 carbon atoms, and combinations thereof.

[0116] Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof;

[0117] X1-X 16 Each occurrence may be selected from C, CR, or N, either identically or differently.

[0118] Among them, one of X5-X8 is selected from C and is related to L. x Connected, X9-X 12 One of them is selected from C and is related to L x Connected;

[0119] R, each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, hydroxyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0120] Adjacent substituents R can optionally connect to form a ring.

[0121] In this document, adjacent substituents R can optionally connect to form a ring, which is intended to indicate that any two adjacent substituents R can connect to form a ring. Obviously, any two adjacent R can also not connect to form a ring.

[0122] According to one embodiment of the present invention, wherein the X1-X 16 Each time it appears, it is selected from CR, either the same or different.

[0123] According to one embodiment of the present invention, wherein the X1-X 16 At least one of them is selected from N, for example, one or two are selected from N.

[0124] According to one embodiment of the present invention, the second compound has a structure represented by formula 2-a:

[0125]

[0126] in,

[0127] L x Each occurrence is the same or different of a single bond, a substituted or unsubstituted alkylene group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3-20 carbon atoms, a substituted or unsubstituted arylene group having 6-30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3-30 carbon atoms, and combinations thereof.

[0128] Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof;

[0129] X1-X5, X7-X 10 and X 12 -X 16 Each occurrence is either identical or different and is selected from CR or N;

[0130] R, each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, hydroxyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0131] Adjacent substituents R can optionally connect to form a ring.

[0132] According to one embodiment of the present invention, wherein X1-X5, X7-X 10 and X 12 -X 16 Each time it appears, it is selected from CR, either the same or different.

[0133] According to one embodiment of the present invention, wherein X1-X5, X7-X 10 and X 12 -X 16 At least one of them is selected from N, for example, one or two are selected from N.

[0134] According to one embodiment of the present invention, wherein the L x Each time it appears, it is selected from single bonds, substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, or combinations thereof.

[0135] According to one embodiment of the present invention, wherein the L xEach time it appears, it is selected from single bonds, substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, or combinations thereof, either identically or differently.

[0136] According to one embodiment of the present invention, wherein the L x It appears as a single key each time.

[0137] According to one embodiment of the present invention, wherein the Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, or combinations thereof.

[0138] According to one embodiment of the invention, wherein Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiopheneyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted quinolinyl, or combinations thereof.

[0139] According to one embodiment of the invention, wherein the R, each time it appears, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, cyano, isocyano, hydroxyl, mercapto, and combinations thereof.

[0140] According to one embodiment of the invention, wherein the R, each time it appears, is selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, and combinations thereof.

[0141] According to one embodiment of the invention, wherein R, each time it appears, is selected from the group consisting of: hydrogen, deuterium, fluorine, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, and combinations thereof.

[0142] According to one embodiment of the present invention, the second compound is selected from the group consisting of compounds X-1 to X-133, the specific structures of which are given in claim 12.

[0143] According to one embodiment of the present invention, the hydrogen in compounds X-1 to X-133 can be partially or completely replaced by deuterium.

[0144] According to one embodiment of the present invention, the light-emitting layer further comprises at least one phosphorescent material.

[0145] According to one embodiment of the present invention, the maximum emission wavelength of the phosphorescent material is greater than or equal to 400 nm and less than or equal to 800 nm.

[0146] According to one embodiment of the present invention, the maximum emission wavelength of the phosphorescent material is greater than or equal to 450 nm and less than or equal to 700 nm.

[0147] According to one embodiment of the present invention, the maximum emission wavelength of the phosphorescent material is greater than or equal to 500 nm and less than or equal to 600 nm.

[0148] According to one embodiment of the present invention, the phosphorescent material is a metal complex, and the metal complex has Ir(L) a ) m (L b ) n (L c ) q The general formula;

[0149] L a L b L c These are the first, second, and third ligands that coordinate with the metal Ir, respectively; L a L b L c They can be selectively linked to form multidentate ligands;

[0150] L a L b L c They can be the same or different; m is 1, 2, or 3; n is 0, 1, or 2; q is 0, 1, or 2; the sum of m, n, and q equals the oxidation state of metal Ir; when m is greater than or equal to 2, multiple L a They can be the same or different; when n is 2, the two Ls b They can be the same or different; when q is 2, the two Ls c They can be the same or different;

[0151] L aIt has the structure shown in Equation 3:

[0152]

[0153] When ring C1 and ring C2 appear, they are selected, either identically or differently, from substituted or unsubstituted aromatic rings having 5-30 ring atoms, substituted or unsubstituted heteroaromatic rings having 5-30 ring atoms, or combinations thereof;

[0154] Q1 and Q2 are selected from C or N each time they appear, either the same or different.

[0155] R 11 and R 12 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0156] R 11 and R 12 Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0157] Adjacent substituent R 11 R 12 They can be arbitrarily connected to form a loop;

[0158] L b and L c Each occurrence may be the same or different, selected from monoanionic bidentate ligands.

[0159] According to one embodiment of the present invention, wherein the L a It has a structure as shown in Equation 3-a:

[0160]

[0161] Y is selected from the group consisting of O, S, Se, NR1, CR1R1 and SiR1R1; when two R1s exist simultaneously, the two R1s are either the same or different.

[0162] Y1-Y4 are selected from CR2 or N each time they appear, either identically or differently;

[0163] Y5-Y 12 Each occurrence may be selected from C, CR2, or N, either identically or differently.

[0164] R2, each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms;

[0165] Adjacent substituents R2 can optionally connect to form a ring.

[0166] In this embodiment, "adjacent substituents R2 can optionally connect to form a ring" is intended to mean that any one or more groups of adjacent substituents R2 can connect to form a ring. Obviously, these substituents may also not connect to form a ring.

[0167] According to one embodiment of the present invention, wherein the L b L c Each occurrence may be selected from any of the following structures, either identically or differently:

[0168]

[0169] in,

[0170] R a R b and R c Each occurrence, whether identical or different, indicates single substitution, multiple substitution, or no substitution;

[0171] Xb Each time it appears, choose from the following groups, either the same or different: O, S, Se, NR N1 and CR C1 R C2 ;

[0172] X c and X d Each time it appears, choose from the following groups, either the same or different: O, S, Se, and NR. N2 ;

[0173] R a R b R c R N1 R N2 R C1 and R C2 Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0174] Adjacent substituent R a R b R c R N1 R N2 R C1 and R C2 They can be arbitrarily connected to form a ring.

[0175] In this embodiment, "adjacent substituent R" a R b R c R N1 R N2 R C1 and R C2 "Can be optionally linked to form a ring" is intended to indicate that adjacent substituent groups therein, for example, adjacent substituent Ra Between, adjacent substituents R b Between, adjacent substituents R c Between, adjacent substituents R a and R b Between, adjacent substituents R a and R c Between, adjacent substituents R b and R c Between, adjacent substituents R a and R N1 Between, adjacent substituents R b and R N1 Between, adjacent substituents R a and R C1 Between, adjacent substituents R a and R C2 Between, adjacent substituents R b and R C1 Between, adjacent substituents R b and R C2 Between, adjacent substituents R a and R N2 Between, and adjacent substituents R b and R N2 Between these substituents, any one or more of these substituent groups can connect to form a ring. Obviously, these substituents can also not connect to form a ring.

[0176] According to one embodiment of the present invention, the light-emitting layer is in direct contact with the electron transport layer.

[0177] According to one embodiment of the present invention, the light-emitting layer is in direct contact with the electron-blocking layer.

[0178] According to one embodiment of the present invention, the light-emitting layer is formed by vapor deposition after premixing a first compound and a second compound.

[0179] According to one embodiment of the present invention, the light-emitting layer is formed by pre-mixing a first compound and a second compound and then co-depositing with a phosphorescent material.

[0180] Currently, commercially available green OLED devices typically employ dual host materials: a p-type host (hole transporter) and an n-type host (electron transporter) to achieve superior device performance. The n-type host material with the structure of Formula 1 can transport electrons, and our research has shown that it can simultaneously function as an electron transporter. Similarly, the p-type host material can transport holes, thus serving as either a hole transporter or an electron blocking material. Therefore, we designed a device structure of p-type host material (as EBL) / p-type host material: n-type host material: GD (as EML) / n-type host material (as ETL). This structure offers advantages in two ways: firstly, it uses fewer material types, reducing costs; secondly, it reduces defects formed at the interfaces between different materials, further improving device performance. Furthermore, further research indicates that, preferably, when the p-type host material is a compound with the structure represented by Formula 2 in this application, it can be well-matched with the first compound with the structure of Formula 1 as a light-emitting layer and is also highly suitable for use in electron blocking layers. This approach effectively reduces the number of material types while maintaining excellent device performance, demonstrating promising commercial applications.

[0181] Combination with other materials

[0182] The materials described in this invention for specific layers in organic light-emitting devices can be used in combination with a variety of other materials present in the device. These combinations of materials are described in detail in paragraphs 0132-0161 of U.S. Patent Application US2016 / 0359122A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned herein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0183] Materials described herein for use in specific layers of organic light-emitting devices can be used in combination with a variety of other materials present in said devices. For example, the compounds disclosed herein can be used in combination with a variety of light-emitting dopants, substrates, transport layers, blocking layers, implantation layers, electrodes, and other possible layers. These combinations of materials are described in detail in paragraphs 0080-0101 of U.S. Patent Application US2015 / 0349273A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned herein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0184] This invention does not limit the preparation methods of the selected first and second compounds. Those skilled in the art can prepare them using conventional synthesis methods, and their preparation methods will not be described in detail here. The preparation methods for organic electroluminescent devices are not limited; the preparation methods of the device embodiments described below are merely examples and should not be construed as limitations. Those skilled in the art can reasonably improve the preparation methods of the device embodiments described below based on existing technology. For example, the proportions of various materials in the light-emitting layer are not particularly limited. Those skilled in the art can reasonably select them within a certain range based on existing technology. For instance, based on the total weight of the light-emitting layer materials, the main material can account for 70%-99%, and the light-emitting material can account for 1%-30%; or the main material can account for 90%-98%, and the light-emitting material can account for 2%-10%; or the main material can account for 87%-98%, and the light-emitting material can account for 2%-13%. Furthermore, the main material can consist of one or two materials, wherein the ratio of the two main materials to the main material can be 99:1 to 1:99; or, the ratio can be 80:20 to 20:80; or, the ratio can be 60:40 to 40:60. The characteristics of the light-emitting devices prepared in the examples were tested using conventional equipment in the art (including but not limited to evaporation machines manufactured by Angstrom Engineering, optical testing systems and lifetime testing systems manufactured by Suzhou Fushida, ellipsometers manufactured by Beijing Liangtuo, etc.) and methods well known to those skilled in the art. Since those skilled in the art are familiar with the use of the above-mentioned equipment, testing methods, and other related content, and can obtain the inherent data of the samples definitively and without being affected, the above-mentioned related content will not be elaborated further in this patent.

[0185] Device Examples

[0186] Example 1: Preparation of phosphorescent green organic electroluminescent devices.

[0187] First, a 0.7mm thick glass substrate is used, on which a pre-patterned design is applied. A thick indium tin oxide (ITO) substrate was used as the anode 110. After washing the substrate with deionized water and detergent, the ITO surface was treated with oxygen plasma and UV ozone. Subsequently, the substrate was dried in a glove box to remove moisture and then placed on a support and transferred to a vacuum chamber. The organic layer specified below was applied at a vacuum degree of approximately 10... -6 In the case of Torr, The rate was achieved by sequentially depositing compounds HT and PD on the anode layer via vacuum thermal evaporation: first, compounds HT and PD were simultaneously deposited as hole injection layers (HIL, 97:3). )120, vapor-deposited compound HT is used as a hole transport layer (HTL, )130, vapor-deposited compound X-127 is used as an electron blocking layer (EBL, )140, on which compounds X-127, A-53, and GD are simultaneously deposited as luminescent layers (EML, 263:113:24, )150, while simultaneously evaporating compounds A-53 and Liq as electron transport layers (ETL, 40:60, 170, vapor deposition A Liq layer of thickness 180 was used as the electron injection layer (EIL). Finally, aluminum was vapor-deposited as the cathode. 190. The device is then transferred back to the glove box and sealed with a glass cover to complete the device. Note that compounds X-127 and A-53 can also be premixed in a 7:3 weight ratio beforehand and then co-evaporated with compound GD to form the luminescent layer 150.

[0188] Example 2: The preparation method is the same as in Example 1, except that compound X-127 in the electron blocking layer and the light emitting layer is replaced with compound X-4.

[0189] Comparative Example 1: The preparation method was the same as in Example 1, except that compound X-127 in the electron blocking layer was replaced with compound X-4.

[0190] Comparative Example 2: The preparation method was the same as in Example 1, except that compound A-53 in the electron transport layer was replaced with compound ET.

[0191] Comparative Example 3: The preparation method was the same as in Example 1, except that compound X-127 in the electron blocking layer was replaced with compound X-4, and compound A-53 in the electron transport layer was replaced with compound ET.

[0192] The detailed layer structure and thickness of the device are shown in the table below. The device uses more than one material; it is obtained by doping different compounds in the stated weight ratios.

[0193] Table 1. Partial device structures of Examples 1-2 and Comparative Examples 1-3

[0194]

[0195] The structural formulas of the compounds HT, PD, X-127, X-4, A-53, GD, ET, and Liq used in the device are shown below:

[0196] Table 2 summarizes the device performance of Examples 1-2 and Comparative Examples 1-3. Among them, color coordinates and maximum emission wavelength λ are specified. max Voltage V, current efficiency CE, power efficiency PE, and external quantum efficiency EQE are all at a current density of 15 mA / cm². 2The device lifetime data for LT97 was measured at a current density of 15 mA / cm². 2 The calculated value is as follows: at 80 mA / cm 2 The measured lifetime of the device when the brightness decays to 97% of the initial brightness under driving is calculated with an acceleration factor of 1.8.

[0197] Table 2. Device performance in Examples 1-2 and Comparative Examples 1-3

[0198]

[0199]

[0200] discuss:

[0201] Table 2 shows the test results of electroluminescent devices with phosphorescent green light devices at a maximum emission wavelength of around 528 nm, including combinations of different electron blocking materials, electron transport materials, and host materials. As can be seen from the color coordinates and maximum emission wavelengths, the color coordinates of the examples and comparative examples are basically the same.

[0202] Example 1 used a specific combination of first compound A-53 and second compound X-127. Specifically, first compound A-53 and Liq were used in the electron transport layer, and second compound X-127 was used in the electron blocking layer. Simultaneously, first compound A-53 and second compound X-127 served as two host materials in the light-emitting layer, respectively. Comparative Example 1 was the same as Example 1, except that X-4 was used in the electron blocking layer, meaning one of the host materials in the light-emitting layer differed from the electron blocking material. Compared to Comparative Example 1, under the same voltage conditions, Example 1 showed a 2.0 cd / A increase in current efficiency, a 1.3 lm / W increase in power efficiency, and a 0.49% increase in external quantum efficiency; lifetime was also improved by 33 h, an improvement of nearly 14.5%. Comparative Example 2 was the same as Example 1, except that ET was used as the electron transport material. Compared with Comparative Example 2, Example 1 showed a significant reduction in voltage of 0.40V, an increase in current efficiency of 2.3cd / A, a significant increase in power efficiency of 11.3lm / W, and an increase in external quantum efficiency of 0.57%; lifetime was increased by 32 hours, an improvement of nearly 14%. In Comparative Example 3, the first compound A-53 was not used as the electron transport material, and the second compound X-127 was not used as the electron blocking material; compared with Comparative Example 3, Example 1 showed a significant reduction in voltage of 0.37V, an increase in current efficiency of 4.2cd / A, a significant increase in power efficiency of 12.2lm / W, a significant increase in external quantum efficiency of 1.11%, and an increase in lifetime of 55 hours, an improvement of nearly 26.7%.

[0203] Example 2 used a specific combination of the first compound A-53 and the second compound X-4. Specifically, the first compound A-53 and Liq were used in the electron transport layer, and the second compound X-4 was used in the electron blocking layer. The first compound A-53 and the second compound X-4 served as the two host materials in the light-emitting layer, respectively. As expected, compared to Comparative Examples 1-3, Example 2 showed significant improvements in device performance in terms of voltage, efficiency, and lifetime, particularly in lifetime, which increased by 1.15 times, 1.14 times, and 1.38 times, respectively, demonstrating excellent device performance. Furthermore, among the five organic layers shown in Table 2, Examples 1 and 2 used four organic materials, while Comparative Examples 1 and 2 used five organic materials, and Comparative Example 3 used six organic materials. These examples reduced the variety of materials used, potentially reducing material costs or the source of vapor deposition. It should be noted that although the luminescent layer in Examples 1 and 2 is in the form of ternary co-evaporation, compounds X-127 and A-53, and compounds X-4 and A-53 can also be premixed and placed in an evaporation source, and then co-evaporated with GD to form the luminescent layer.

[0204] As can be seen from the above, when the first compound A-53 with the structure represented by Formula 1 is used as an electron transport material in the electron transport layer and the second compound X-127 or X-4 with the structure represented by Formula 2 is used as a hole transport material in the electron blocking layer, and the same first and second compounds are used as the host materials in the light-emitting layer, the device achieves comprehensive improvement in voltage, current efficiency, power efficiency, external quantum efficiency and lifetime, and the overall performance of the device is significantly improved.

[0205] In summary, research has shown that the n-type host material with the structure of Formula 1 possesses excellent electron transport performance and is well-suited for use in the electron transport layer. Therefore, this invention proposes an organic electroluminescent device comprising the following specific structure: the light-emitting layer comprises an n-type host material (first compound) and a p-type host material (second compound) with the structure of Formula 1; wherein the first and second compounds are also used in the electron transport layer and hole blocking layer, respectively. This device structure can effectively reduce the types of materials used in device fabrication, simplify the fabrication process, reduce defects at the organic layer interface, enhance the charge (electron and hole) transport performance between interfaces, and effectively improve device performance. In particular, when the second compound has the structure represented by Formula 2, it can be well combined with the first compound with the structure of Formula 1 in the light-emitting layer of the device as a dual host, and can also be used in the electron blocking layer, significantly improving the overall performance of the device. The organic electroluminescent device with the first compound containing the structure of Formula 1 and the specific device structure disclosed in this invention has excellent device performance and unique advantages, providing possibilities and examples for further optimization of device structures, and has broad prospects in commercial applications.

[0206] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments 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 spirit of the invention. It should be understood that various theories regarding why the invention works are not intended to be limiting.

Claims

1. An organic electroluminescent device, comprising: cathode, anode, A light-emitting layer disposed between the cathode and the anode, an electron transport layer disposed between the cathode and the light-emitting layer, and an electron blocking layer disposed between the anode and the light-emitting layer; The light-emitting layer is in direct contact with the electron transport layer; The electron transport layer comprises a first compound, the electron blocking layer comprises a second compound, and the light-emitting layer comprises the first compound and the second compound; The first compound has the structure represented by Formula 1-a: ； Where Z is selected from O, S, or Se; A1-A6 are selected from CR each time they appear, either identically or differently. x Or N; R y R z Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted. R x R y and R z Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Ar is selected, in the same or different ways, from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof; The second compound has the structure represented by Formula 2: ； in, L x Each time it appears, it is selected from single bonds, substituted or unsubstituted alkylene groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkylene groups having 3-20 carbon atoms, substituted or unsubstituted arylene groups having 6-30 carbon atoms, substituted or unsubstituted heteroarylene groups having 3-30 carbon atoms, and combinations thereof. Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof; X1-X 16 Each occurrence may be selected from C, CR, or N, either identically or differently. Among them, one of X5-X8 is selected from C and is related to L. x Connected, X9-X 12 One of them is selected from C and is related to L x Connected; R, each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, hydroxyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Adjacent substituents R can optionally connect to form a ring.

2. The electroluminescent device as described in claim 1, wherein, R y and R z At least one of them is an aryl group with 6-30 carbon atoms, either substituted or unsubstituted; Ar is selected, either identically or differently, from substituted or unsubstituted aryl groups having 10-30 carbon atoms.

3. The organic electroluminescent device as claimed in claim 1, wherein Z is selected from O or S.

4. The organic electroluminescent device as claimed in claim 3, wherein Z is O.

5. The organic electroluminescent device according to any one of claims 1-3, wherein A1-A6 are selected from CR each time they appear, either identically or differently. x ;where R x Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 cyclic 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.

6. The organic electroluminescent device as claimed in claim 5, wherein R x Each time it appears, it is selected from the group consisting of the following, either the same or different: hydrogen, deuterium, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, and combinations thereof.

7. The organic electroluminescent device according to any one of claims 2-4, wherein Ar, each time it appears, is selected from substituted or unsubstituted aryl groups having 10-30 carbon atoms, and when Ar is selected from substituted aryl groups having 10-30 carbon atoms, the substitution is selected from the group consisting of: deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof.

8. The organic electroluminescent device of claim 7, wherein Ar, each time it appears, is selected from substituted or unsubstituted aryl groups having 10-20 carbon atoms, and when Ar is selected from substituted aryl groups having 10-20 carbon atoms, the substitution is selected from the group consisting of: deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 cyclic carbon atoms, substituted or unsubstituted aryl groups having 6-18 carbon atoms, and combinations thereof.

9. The organic electroluminescent device of claim 7, wherein Ar, each time it appears, is selected from the group consisting of: naphthyl, biphenyl, phenanthrene, terphenyl, triphenylene, deuterated naphthyl, deuterated biphenyl, deuterated phenanthrene, deuterated terphenyl, deuterated triphenylene, and combinations thereof.

10. The organic electroluminescent device of claim 1, wherein the first compound is selected from the group consisting of: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ， , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ； in, Optionally, the hydrogen in compounds A-1 to A-138 can be partially or completely replaced by deuterium.

11. The organic electroluminescent device of claim 1, wherein the second compound has a structure represented by formula 2-a: ； in, L x Each occurrence is the same or different of a single bond, a substituted or unsubstituted alkylene group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3-20 carbon atoms, a substituted or unsubstituted arylene group having 6-30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3-30 carbon atoms, and combinations thereof. Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof; X1-X5, X7-X 10 and X 12 -X 16 Each occurrence may be selected from C, CR, or N, either identically or differently. R, each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, hydroxyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Adjacent substituents R can optionally connect to form a ring.

12. The organic electroluminescent device as claimed in claim 1 or 11, wherein, L x Each time it appears, it is selected from single bonds, substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, or combinations thereof.

13. The organic electroluminescent device as described in claim 12, wherein, L x Each time it appears, it is selected from single bonds, substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, or combinations thereof, either identically or differently.

14. The organic electroluminescent device as claimed in claim 12, wherein, L x It appears as a single key each time.

15. The organic electroluminescent device as claimed in claim 1 or 11, wherein, Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, or combinations thereof.

16. The organic electroluminescent device as claimed in claim 15, wherein, Ar1 and Ar2, each time appearing, are selected from the same or different groups of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted quinolinyl, or combinations thereof.

17. The organic electroluminescent device as claimed in claim 1 or 11, wherein, X1-X 16 Each time it appears, it is selected from C or CR, either identically or differently; wherein each time R appears, it is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 cyclic carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, cyano, isocyano, hydroxyl, mercapto, and combinations thereof.

18. The organic electroluminescent device of claim 17, wherein, R, each time appearing, is selected from the group consisting of: hydrogen, deuterium, fluorine, substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, and combinations thereof.

19. The organic electroluminescent device as claimed in claim 17, wherein, R, each time appearing, is selected from the group consisting of, either identically or differently from, hydrogen, deuterium, fluorine, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, and combinations thereof.

20. The organic electroluminescent device of claim 1 or 11, wherein the second compound is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； in, Optionally, the hydrogen in compounds X-1 to X-133 can be partially or completely replaced by deuterium.

21. The organic electroluminescent device of claim 1, wherein the light-emitting layer further comprises at least one phosphorescent material.

22. The electroluminescent device of claim 21, wherein the maximum emission wavelength of the phosphorescent material is greater than or equal to 400 nm and less than or equal to 800 nm.

23. The electroluminescent device of claim 22, wherein the maximum emission wavelength of the phosphorescent material is greater than or equal to 450 nm and less than or equal to 700 nm.

24. The electroluminescent device of claim 22, wherein the maximum emission wavelength of the phosphorescent material is greater than or equal to 500 nm and less than or equal to 600 nm.

25. The organic electroluminescent device as claimed in claim 1, wherein the light-emitting layer is in direct contact with the electron blocking layer.

26. The organic electroluminescent device of claim 1, wherein the light-emitting layer is formed by vapor deposition after premixing the first compound and the second compound.

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