Charge transport material with deep LUMO and organic electroluminescent device containing charge transport material

Abstract

Disclosed are a charge transport material having a deep LUMO and an organic electroluminescent device comprising the same. The charge transport material has a LUMO level of-2.9 eV or less, and has a specific structure represented by Formula 1. The charge transport material can be used for an electron transport layer in an organic electroluminescent device, the service life of the device can be greatly prolonged, and better device performance can be provided. The invention further discloses the electronic equipment.

Description

Technical Field

[0001] This invention relates to materials for use in organic electronic devices, such as organic light-emitting devices. More particularly, it relates to a deep LUMO charge-transport material and an organic electroluminescent device comprising the same. 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 electroluminescent 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] The applicant's previous patent application CN110003254A disclosed a general structure as follows: The compounds, which disclose specific compounds. The application focuses on the properties of its compounds that meet the requirements of candidate compounds for TADF materials, such as having a very narrow emission spectrum and achieving high-saturation deep blue emission. However, the application does not focus on the properties of its compounds as charge transport materials, nor does it disclose or teach how its compounds affect device performance as charge transport materials.

[0009] CN108409761A discloses a general structure as follows: The application focuses on the effect of the compound as a phosphorescent host material or hole injection material on device performance, but does not disclose or teach the effect of the compound as a charge transport material on device performance, especially TADF device performance.

[0010] Therefore, in order to meet the industry's ever-increasing demands for device performance, especially for TADF devices, such as higher device efficiency and longer lifetime, new charge transport materials and new devices still require further research and development. Summary of the Invention

[0011] This invention aims to provide a charge transport material with a deep LUMO energy level and a novel organic electroluminescent device incorporating said charge transport material to solve at least some of the aforementioned problems. The charge transport material has a LUMO energy level less than or equal to -2.9 eV and has a specific structure represented by Formula 1. The charge transport material can be used as an electron transport layer in an organic electroluminescent device, significantly improving device lifetime and providing better device performance.

[0012] According to one embodiment of the present invention, a charge transport material is disclosed, the charge transport material comprising a first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1:

[0013]

[0014] Among them, ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms;

[0015] Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR';

[0016] The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution;

[0017] And there exists at least one substituent R that is R a The R aSelected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof;

[0018] X1 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop;

[0019] R', R, 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0020] Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop;

[0021] And the first compound is not a fullerene-type compound.

[0022] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0023] anode,

[0024] cathode,

[0025] And an organic layer disposed between the anode and the cathode;

[0026] The organic layer comprises a first organic layer and a light-emitting layer;

[0027] The first organic layer is disposed between the cathode and the light-emitting layer;

[0028] The first organic layer comprises at least one charge transport material, the charge transport material comprising a first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1:

[0029]

[0030] Among them, ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms;

[0031] Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR';

[0032] The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution;

[0033] And there exists at least one substituent R that is R a The R a 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;

[0034] X1 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop;

[0035] R', R, 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 1-20 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0036] Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop;

[0037] And the first compound is not a fullerene-type compound.

[0038] The charge transport material disclosed in this invention has a LUMO energy level less than or equal to -2.9 eV and has a specific structure represented by Formula 1. The novel organic electroluminescent device disclosed in this invention comprises a first organic layer and a light-emitting layer, the first organic layer being disposed between a cathode and a light-emitting layer. The first organic layer at least comprises a first compound, the first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a specific structure represented by Formula 1. The first compound can be used as an electron transport material in the organic electroluminescent device. The organic electroluminescent device significantly improves device lifetime and provides better device performance. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of an organic light-emitting device that may contain the organic electroluminescent devices disclosed herein.

[0040] Figure 2 This is a schematic diagram of another organic light-emitting device that may contain the organic electroluminescent devices disclosed herein. Detailed Implementation

[0041] 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. The figures are not necessarily drawn to scale, and some layer structures may be omitted as needed. 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 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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. 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.

[0046] 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.

[0047] The materials and structures described in this article can also be used in other organic electronic devices listed above.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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).

[0052] 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.

[0053] 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).

[0054] In this document, all "LUMO levels" are represented by negative values; the smaller the value (i.e., the larger the absolute value), the deeper the energy level. The statement that an energy level is less than a certain number in this application means that the energy level is numerically smaller than that number, i.e., has a more negative value. For example, "the LUMO level of the first compound is less than -2.5 eV" in this application means that the LUMO level of the first compound is numerically more negative than -2.5 eV; for example, the LUMO level of the first compound is -2.96 eV.

[0055] Definition of the term "substituent group"

[0056] Halogens or halides—as used herein—include fluorine, chlorine, bromine, and iodine.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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:

[0079]

[0080] 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:

[0081]

[0082] 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:

[0083]

[0084] 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:

[0085]

[0086] According to one embodiment of the present invention, a charge transport material is disclosed, the charge transport material comprising a first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1:

[0087]

[0088] Among them, ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms;

[0089] Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR';

[0090] The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution;

[0091] And there exists at least one substituent R that is R a The R a 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;

[0092] X1 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop;

[0093] R', R, 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 1-20 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0094] Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop;

[0095] And the first compound is not a fullerene-type compound.

[0096] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0097] anode,

[0098] cathode,

[0099] And an organic layer disposed between the anode and the cathode;

[0100] The organic layer comprises a first organic layer and a light-emitting layer;

[0101] The first organic layer is disposed between the cathode and the light-emitting layer;

[0102] The first organic layer comprises at least one charge transport material, the charge transport material comprising a first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1:

[0103]

[0104] Among them, ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms;

[0105] Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR';

[0106] The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution;

[0107] And there exists at least one substituent R that is R a The R a 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;

[0108] X1 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop;

[0109] R', R, 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0110] Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop;

[0111] And the first compound is not a fullerene-type compound.

[0112] In this paper, "adjacent substituents R, R a R x "Optionally connected to form a ring" is intended to indicate that adjacent substituent groups therein, for example, between two substituents R, two substituents R a Between the two substituents R x Between, substituents R and R a Between, substituents R and R x Between, substituent R a and R x Between these adjacent substituent groups, any one or more can connect to form a ring. Obviously, these adjacent substituents may also not connect to form a ring.

[0113] Fullerenes are a class of carbon-based compounds with cage-like structures. These cage-like structures include spherical, ellipsoidal, tubular, onion-like, and clusters containing all four types. Typical members of the fullerene family include C646. 20 C 24 C 26 C 28 C 32 C 50 C 60 C 70 ...C 540 In this application, a fullerene-type compound refers to a compound containing carbon and partially substituted heteroatoms with a cage-like structure. Its structure is similar to that of a fullerene, including spherical cage-like, ellipsoidal cage-like, tubular, onion-like, and clusters containing the above four cage-like structures. The first compound disclosed in this application is not a fullerene-type compound; its key point is that the molecules of the first compound having the structure represented by Formula 1 do not constitute a spatially closed structure, such as spherical cage-like, ellipsoidal cage-like, tubular, onion-like, and clusters containing the above four cage-like structures.

[0114] According to one embodiment of the present invention, the first compound has a structure represented by Formula 1-1:

[0115]

[0116] Among them, ring A, ring B, ring C, ring D, and ring E are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms;

[0117] Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR';

[0118] X1 to X3, X8 to X12 Selected from CR x Or N, and X2 and X3, X6 and X9, X7 and X 10 At least one of the four groups consisting of X8 and X1 is selected from CR. x And the set of R x The connection forms a loop;

[0119] The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution;

[0120] And there exists at least one substituent R that is R a The R a 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;

[0121] R', 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0122] Adjacent substituents R, R a R x They can be arbitrarily connected to form a ring.

[0123] According to one embodiment of the present invention, ring A, ring B, ring C, and ring D are each independently selected from five-membered unsaturated carbon rings, aromatic rings having 6-30 carbon atoms, or heteroaromatic rings having 3-30 carbon atoms.

[0124] According to one embodiment of the present invention, ring A, ring B, ring C, and ring D are each independently selected from five-membered unsaturated carbon rings, aromatic rings having 6-18 carbon atoms, or heteroaromatic rings having 3-18 carbon atoms.

[0125] According to one embodiment of the present invention, ring A, ring B, ring C, and ring D are each independently selected from benzene ring, pyridine ring, naphthyl ring, phenanthrene ring, anthracene ring, indene ring, fluorene ring, indole ring, carbazole ring, benzofuran ring, dibenzofuran ring, benzothiophene ring, dibenzothiophene ring, benzothiophene ring, dibenzoselenophene ring, dibenzoselenophene ring, cyclopentadiene ring, furan ring, thiophene ring, and thiophene ring.

[0126] According to one embodiment of the present invention, Y is selected from B, P=O or P=S each time it appears.

[0127] According to one embodiment of the present invention, Y is B.

[0128] According to an embodiment of the present invention, in Formula 1, X2 and X3 are both selected from CR x And the two substituents R x The connection forms a loop.

[0129] According to an embodiment of the present invention, in Formula 1, X4 and X5 are both selected from CR x And the two substituents R x The connection forms a loop.

[0130] According to an embodiment of the present invention, in formula 1, both X6 and X7 are selected from CR. x And the two substituents R x The connection forms a loop.

[0131] According to an embodiment of the present invention, in Formula 1, both X8 and X1 are selected from CR x And the two substituents R x The connection forms a loop.

[0132] According to an embodiment of the present invention, in formula 1, X2 and X3, X6 and X7 are all selected from CR. x And the two sets of R x Connect them separately to form a loop.

[0133] According to one embodiment of the present invention, in Formula 1, at least one of the four groups consisting of X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is carbon and is connected by a C-C single bond.

[0134] According to an embodiment of the present invention, in formula 1-1, both X2 and X3 are selected from CR. x And the two substituents R x The connection forms a loop.

[0135] According to an embodiment of the present invention, in formula 1-1, both X6 and X9 are selected from CR. xAnd the two substituents R x The connection forms a loop.

[0136] According to an embodiment of the present invention, in formula 1-1, X2 and X3, X6 and X9 are all selected from CR. x And the two sets of R x Connect them separately to form a loop.

[0137] According to one embodiment of the present invention, in Formula 1, Y is B, and at least two of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 are selected from CR. x And the two sets of R x Connect them separately to form a loop.

[0138] According to one embodiment of the present invention, the first compound has a structure represented by formula 2-1 or formula 2-2:

[0139]

[0140] Among them, T1 to T 17 Each occurrence is either identical or different and is selected from CR or N;

[0141] 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 aroxy groups having 6-30 carbon atoms, and substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0142] And there exists at least one substituent R that is R a The R a 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;

[0143] Adjacent substituents R, R a They can be arbitrarily connected to form a ring.

[0144] In this paper, "adjacent substituents R, R a "Optionally connected to form a ring" is intended to indicate that adjacent substituent groups therein, for example, between two substituents R, two substituents R a Between, substituents R and R a Between these adjacent substituent groups, any one or more can connect to form a ring. Obviously, these adjacent substituents may also not connect to form a ring.

[0145] According to one embodiment of the present invention, the first compound has a structure represented by Formula 2-1.

[0146] According to one embodiment of the present invention, in Formula 2-1, T4 to T7 are selected from CR, and at least one substituent R is R. a The R a 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.

[0147] According to one embodiment of the present invention, in formula 2-1, T5 is selected from CR a ; and the R a 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.

[0148] According to an embodiment of the present invention, in formula 2-2, T 15 To T 17 Selected from CR, and having at least one substituent R as R a The R a 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.

[0149] According to an embodiment of the present invention, in formula 2-2, T 16 Selected from CR a ; and the R a 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.

[0150] According to one embodiment of the present invention, wherein the R a Choose a group consisting of the following structures:

[0151]

[0152]

[0153] According to one embodiment of the present invention, wherein the R a Selected from substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms.

[0154] According to one embodiment of the present invention, wherein the R a It has a structure represented by Equation 2-A:

[0155]

[0156] Wherein, "*" indicates the connection position between Equation 2-A and Equation 2-1 or Equation 2-2;

[0157] E1-E8 are selected from CR each time they appear, either identically or differently. e Or N;

[0158] L is selected from single bond, O, S, SO2, Se, NR", CR”R", SiR”R", GeR”R", BR", PR", P(O)R", substituted or unsubstituted alkylene with 2-20 carbon atoms, substituted or unsubstituted heteroalkylene with 1-20 carbon atoms, substituted or unsubstituted cycloalkylene with 3-20 cyclic carbon atoms, substituted or unsubstituted heterocyclic with 3-20 cyclic atoms, substituted or unsubstituted arylene with 6-30 carbon atoms, substituted or unsubstituted heteroarylene with 3-30 carbon atoms, or combinations thereof;

[0159] R eThe letter "R" is selected, in the same or different manner, 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 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 ring 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 alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted... Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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.

[0160] According to one embodiment of the present invention, in Formula 2-A, L is selected from single bonds.

[0161] According to one embodiment of the present invention, wherein the R', R, 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 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, cyano groups, and combinations thereof.

[0162] Adjacent substituents R, R x They can be arbitrarily connected to form a ring.

[0163] According to one embodiment of the present invention, wherein the R', R, 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 1-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, cyano groups, and combinations thereof.

[0164] According to one embodiment of the present invention, wherein the R e 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 aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, cyano groups, and combinations thereof.

[0165] Adjacent substituent R e They can be arbitrarily connected to form a ring.

[0166] According to one embodiment of the present invention, wherein the R e Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, and combinations thereof.

[0167] According to one embodiment of the present invention, the LUMO energy level of the first compound is less than or equal to -2.92 eV.

[0168] According to one embodiment of the present invention, the LUMO energy level of the first compound is less than or equal to -2.95 eV.

[0169] According to one embodiment of the present invention, the first compound is selected from the group consisting of compounds ET-1 to ET-203, and the specific structures of compounds ET-1 to ET-203 are given in claim 8.

[0170] According to one embodiment of the present invention, the light-emitting layer comprises at least one light-emitting material, wherein the light-emitting material is a fluorescent light-emitting material.

[0171] According to one embodiment of the present invention, the fluorescent luminescent material is a common fluorescent luminescent material or a delayed fluorescence material.

[0172] According to one embodiment of the present invention, the luminescent material has a structure represented by one of Formulas 3 to 8:

[0173]

[0174] In Equations 3 to 8, Y is selected from N or CR each time it appears, either the same or different. y;

[0175] R y Each time it appears, it is selected from the group consisting of the same or different elements: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 ring 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 alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted... Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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;

[0176] Adjacent substituent R y They can be arbitrarily connected to form a ring.

[0177] According to one embodiment of the present invention, R y At least one of them is selected from deuterium, substituted or unsubstituted alkyl groups having 1-20 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 amino groups having 0-20 carbon atoms, and combinations thereof.

[0178] According to one embodiment of the present invention, Y is selected from CR each time it occurs, either identically or differently. y .

[0179] According to one embodiment of the present invention, the luminescent material has a structure represented by Formula 7.

[0180] According to one embodiment of the present invention, in Formula 7, Y is selected from CR each time it appears, either the same or different. y And R y At least one of them is selected from deuterium, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, and combinations thereof.

[0181] According to one embodiment of the present invention, the luminescent material is selected from the group consisting of compounds BD1 to BD27, and the specific structures of compounds BD1 to BD27 are given in claim 9.

[0182] According to one embodiment of the present invention, the first compound is different from the luminescent material.

[0183] According to one embodiment of the present invention, when the luminescent material is a delayed fluorescence luminescent material, the band gap between the first excited singlet state and the first excited triplet state of the delayed fluorescence luminescent material is less than 0.3 eV.

[0184] According to one embodiment of the present invention, the first organic layer is an electron transport layer.

[0185] According to one embodiment of the present invention, the electron transport layer further comprises at least one metal complex.

[0186] According to one embodiment of the present invention, the metal complex comprises a ligand L represented by Formula 9. a :

[0187]

[0188] Q1 to Q6 are each independently selected from CR q Or N; R q 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 alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, substituted or unsubstituted silyl groups having 3-20 carbon atoms, cyano, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms.

[0189] Where W is selected from NR N , O, S or Se;

[0190] R NEach time it appears, it is selected from the group consisting of the following, either identically or differently: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 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... Alkenyl groups having 2-20 carbon atoms, 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), and amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms (substituted or unsubstituted).

[0191] According to one embodiment of the present invention, the metal complex is selected from 8-hydroxyquinoline-lithium, 8-hydroxyquinoline-sodium, 8-hydroxyquinoline-potassium, bis(8-hydroxyquinoline)-beryllium, bis(8-hydroxyquinoline)-magnesium, bis(8-hydroxyquinoline)-calcium, tris(8-hydroxyquinoline)-boron, tris(8-hydroxyquinoline)-aluminum, or tris(8-hydroxyquinoline)-gallium.

[0192] According to another embodiment of the present invention, an electronic device is also disclosed, which includes an organic electroluminescent device, wherein the specific structure of the organic electroluminescent device is as shown in any of the foregoing embodiments.

[0193] Combination with other materials

[0194] 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.

[0195] 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.

[0196] In the examples of material synthesis, unless otherwise stated, all reactions were carried out under nitrogen protection. All reaction solvents were anhydrous and used as is from commercial sources. The synthesized products were structurally confirmed and characterized using one or more instruments conventional in the art (including but not limited to Bruker's nuclear magnetic resonance spectrometer, Shimadzu's liquid chromatograph, liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, differential scanning calorimeter, Shanghai Lingguang Technology's fluorescence spectrophotometer, Wuhan Kesite's electrochemical workstation, Anhui Beiyike's sublimation apparatus, etc.) in methods well known to those skilled in the art. In the examples of devices, the characteristics of the devices were also tested using equipment conventional 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.) in 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 unaffected, the above-mentioned related content will not be elaborated further in this patent.

[0197] Material synthesis example:

[0198] The preparation method of the first compound of the present invention is not limited. Typically, but not limited, the following compound is used as an example, and its synthetic route and preparation method are as follows:

[0199] Synthesis Example 1: Synthesis of Compound ET-2

[0200] Step 1: Synthesis of Intermediate 1

[0201]

[0202] Under nitrogen protection, toluene / ethanol / water (8 / 1 / 1, v / v, 300.0 mL total) was added to a three-necked flask, followed by the sequential addition of 9-(3-bromo-2-chlorobenzene)-9-hydro-carbazole (24.0 g, 67.6 mmol), (3-(9-hydro-carbazole)phenyl)boronic acid (19.4 g, 67.6 mmol), tetrakis(triphenylphosphine)palladium (2.3 g, 2.0 mmol), and potassium carbonate (18.6 g, 135.1 mmol). The reaction was heated to 110 °C and stirred overnight. After cooling to room temperature, the aqueous phase was extracted with dichloromethane, and the organic phases were combined. The mixture was filtered through diatomaceous earth, concentrated under reduced pressure, and purified by column chromatography (PE / DCM = 10 / 1) to give intermediate 1 (23.0 g, 44.4 mmol, 66% yield).

[0203] Step 2: Synthesis of compound ET-2

[0204]

[0205] Under nitrogen protection, intermediate 1 (23.0 g, 44.4 mmol) was dissolved in tert-butylbenzene (300.0 mL) and added to a three-necked flask. The mixture was then cooled to -30 °C, and tert-butyllithium (75.0 mL, 97.7 mmol) was added dropwise. The mixture was then heated to 60 °C and reacted for 1 h. Pentane was removed under reduced pressure, and the mixture was cooled to -30 °C. Boron tribromide (9.0 mL, 97.7 mmol) was added dropwise. The mixture was then heated to room temperature and stirred for 30 min. The mixture was cooled to 0 °C, and N,N-diisopropylethylamine (19.0 mL, 115.4 mmol) was added dropwise. The mixture was then heated to 120 °C and reacted overnight. The reaction was monitored by TLC until complete. The reaction was quenched with potassium acetate solution, and the solid was collected by filtration. The crude product was recrystallized from toluene to give a yellow solid compound ET-2 (0.7 g, 1.4 mmol, yield 3%), which was identified as the target product with a molecular weight of 492.18.

[0206] Those skilled in the art should understand that the above preparation method is merely an exemplary example, and they can improve it to obtain other compound structures selected in this invention.

[0207] In this invention, the LUMO level (lowest unoccupied orbital) value was determined using an electrochemical cyclic voltammetry method. The test was conducted using a CorrTest CS120 electrochemical workstation manufactured by Wuhan CorrTest Instruments Co., Ltd., employing a three-electrode system: a platinum disk electrode as the working electrode, an Ag / AgNO3 electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode. Anhydrous DMF was used as the solvent, and 0.1 mol / L tetrabutylammonium hexafluorophosphate was used as the supporting electrolyte to prepare a 10... -3For the mol / L solution, nitrogen gas was bubbled into the solution for 10 min to remove oxygen before the test. Instrument parameters were set as follows: scan rate 100 mV / s, potential interval 0.5 mV, test window -1 V to -2.9 V.

[0208] As an example, the LUMO energy levels of the following compounds were determined using the above method, and the specific results are shown in Table 1:

[0209] Table 1. LUMO energy level data of the compounds.

[0210] Compound numbering LUMO(eV) Compound ET-2 -2.96 Compound A -2.66 Compound B -2.90 Compound C -2.71 Compound D -2.68 Compound BD7 >-2.0

[0211] As shown in Table 1, the LUMO energy levels of commonly used comparative compounds in the prior art are all greater than or equal to -2.9 eV, while the LUMO energy level of the compound selected in this invention is -2.96 eV, which has a very deep LUMO energy level and has the potential to become an excellent charge transport material, especially an electron transport material.

[0212] The fabrication methods for organic electroluminescent devices are not limited. The fabrication methods in the following embodiments are merely examples and should not be construed as limiting. Those skilled in the art can make reasonable improvements to the fabrication methods in the following embodiments based on existing technology.

[0213] Device Examples

[0214] Device Example 1

[0215] First, the glass substrate, which has an 80 nm thick indium tin oxide (ITO) anode, is cleaned and then treated with oxygen plasma and UV ozone. After treatment, the substrate is dried in a glove box to remove moisture. The substrate is then mounted on a substrate holder and placed in a vacuum chamber. The organic layer specified below is applied at a vacuum degree of approximately 10... -8 In the case of T, deposition is performed sequentially on the ITO anode via thermal vacuum evaporation at a rate of 0.2–2 Å / s. The compound HI is used as the hole injection layer (HIL). Compound HT is used as a hole transport layer (HTL). Compound EB is used as an electron blocking layer (EBL). Then, compound BD9 was doped into compound BH and co-deposited as an emissive layer (EML, with a weight ratio of compound BH to compound BD9 of 98:2). Compound HB was used as a hole-blocking layer (HBL). On the hole-blocking layer, compound ET-2 and 8-hydroxyquinoline-lithium (Liq) were co-deposited as an electron transport layer (ETL, with a weight ratio of ET-2 to Liq of 40:60). Finally, a 1 nm thick layer of 8-hydroxyquinoline-lithium (Liq) was deposited as the electron injection layer (EIL), and a 120 nm thick layer of aluminum was deposited as the cathode. The device was then transferred back to the glove box and encapsulated with a glass cover and desiccant to complete the device.

[0216] Device Comparison Example 1

[0217] The fabrication method of Comparative Example 1 is the same as that of Example 1, except that compound A is used instead of compound ET-2 in the electron transport layer.

[0218] Device Comparison Example 2

[0219] The device comparative example 2 was prepared in the same manner as device example 1, except that compound B was used instead of compound ET-2 in the electron transport layer.

[0220] Device Comparison Example 3

[0221] The device comparative example 3 was prepared in the same manner as the device example 1, except that compound C was used instead of compound ET-2 in the electron transport layer.

[0222] Device Comparison Example 4

[0223] The device comparative example 4 was prepared in the same manner as device example 1, except that compound D was used instead of compound ET-2 in the electron transport layer.

[0224] Device Comparison Example 5

[0225] The fabrication method of Comparative Example 5 is the same as that of Device Example 1, except that compound BD7 is used instead of compound ET-2 in the electron transport layer.

[0226] The partial device layer structures and thicknesses of Examples 1 and Comparative Examples 1-5 are shown in Table 2 below. The layers used are made of more than one material and are obtained by doping different compounds in the weight ratios described herein.

[0227] Table 2 Partial device structures of the embodiments and comparative examples

[0228]

[0229] The material structure used in the device is shown below:

[0230]

[0231]

[0232] At 10mA / cm 2 The CIE values ​​of Examples 1 and Comparative Examples 1-5 were measured at current density, and the maximum emission wavelength (λ) was determined. maxThe data includes the device's brightness and lifetime (LT97), which is the time it takes for the device's brightness to decay to 97% of its initial brightness. The data are shown in Table 3.

[0233] Table 3 Device data for Example 1 and Comparative Examples 1-5

[0234] Device Number CIE(x, y) <![CDATA[λ max (nm)]]> LT97(h) Example 1 (0.133，0.084) 461 2729 Comparative Example 1 (0.133，0.080) 461 873 Comparative Example 2 (0.135，0.076) 461 43 Comparative Example 3 (0.135，0.084) 460 330 Comparative Example 4 (0.135，0.082) 461 300 Comparative Example 5 (0.132，0.082) 462 0

[0235] discuss:

[0236] As can be seen from the data in Table 3, the maximum emission wavelength of Example 1 and Comparative Examples 1 to 5 are basically the same.

[0237] Example 1 uses a compound with a LUMO energy level less than or equal to -2.9 eV and a specific structure represented by Formula 1 as an electron transport material. Comparative Example 1 uses commercially available compound A as an electron transport material. Data shows that Comparative Example 1 already has a long device lifetime. Remarkably, compared to Comparative Example 1, the lifetime of Example 1 is further significantly improved by 213%. This demonstrates that using a deep LUMO compound with a specific structure as an electron transport material in this application can significantly improve device lifetime and provide superior device performance.

[0238] Comparative Example 2 uses compound B as an electron transport material. Although compound B also has a deep LUMO level of -2.9 eV and the same skeletal structure as compound ET-2 of the present invention, the only difference is that compound B does not have the specific aromatic substituent R in its structure. a However, the data shows that the lifetime of Example 1 was unexpectedly and significantly improved by 62 times compared to Comparative Example 2. This further demonstrates that the use of deep LUMO compounds with specific structures as electron transport materials in this application can significantly improve device lifetime and provide superior device performance.

[0239] Comparative Examples 3 and 4 used compounds C and D as electron transport materials, respectively. Both compounds C and D have shallow LUMO levels. Data shows that, compared to Comparative Examples 3 and 4, the lifetime of Example 1 was significantly improved by 7.3 times and 8.1 times, respectively. This further demonstrates that the present application, by using deep LUMO compounds with specific structures as electron transport materials, can significantly improve device lifetime.

[0240] Comparative Example 5 uses compound BD7 as an electron transport material. Compound BD7 has a shallow LUMO level and does not contain any specific aromatic substituents R. a The data shows that the lifetime of Comparative Example 5 was too short to be measured, which also demonstrates the unique advantage of using deep LUMO compounds with specific structures as electron transport materials in this application.

[0241] In summary, the first compound with a deep LUMO energy level and a specific structure represented by Formula 1 selected in this invention can serve as a charge transport material, especially an electron transport material. When applied to organic electroluminescent devices, especially TADF devices, it can significantly improve device lifetime and provide superior device performance, exhibiting unexpected unique advantages and broad application prospects.

[0242] 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. A charge transport material comprising a first compound having a LUMO level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1: in, Ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings having 5-30 carbon atoms or unsaturated heterocycles having 3-30 carbon atoms; Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR'; The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution; And there exists at least one substituent R that is R a The R a 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 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop; R', R, 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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; Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop; And the first compound is not a fullerene-type compound.

2. An organic electroluminescent device, comprising: anode, cathode, And an organic layer disposed between the anode and the cathode; The organic layer comprises a first organic layer and a light-emitting layer; The first organic layer is disposed between the cathode and the light-emitting layer; The first organic layer comprises at least one charge transport material, the charge transport material comprising a first compound having a LUMO energy level less than or equal to -2.9 eV, and the first compound having a structure represented by Formula 1: Among them, ring A, ring B, ring C, and ring D are each independently selected from unsaturated carbon rings with 5-30 carbon atoms or unsaturated heterocycles with 3-30 carbon atoms; Y is selected from B, P=O, P=S, As, As=O, As=S, SiR' or GeR'; The same or different occurrences of R each indicate monosubstitution, polysubstitution, or no substitution; And there exists at least one substituent R that is R a The R a 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 to X8 are selected from CR x Or N, and at least one of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 is selected from CR. x And the set of R x The connection forms a loop; R', R, 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 aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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; Adjacent substituents R, R a R x They can be arbitrarily connected to form a loop; And the first compound is not a fullerene-type compound.

3. The organic electroluminescent device as described in claim 2, wherein, Ring A, ring B, ring C, and ring D are each independently selected from five-membered unsaturated carbon rings, aromatic rings with 6-30 carbon atoms, or heteroaromatic rings with 3-30 carbon atoms; Preferably, ring A, ring B, ring C, and ring D are each independently selected from five-membered unsaturated carbon rings, aromatic rings having 6-18 carbon atoms, or heteroaromatic rings having 3-18 carbon atoms; More preferably, ring A, ring B, ring C, and ring D are each independently selected from benzene rings, pyridine rings, naphthyl rings, phenanthrene rings, anthracene rings, indene rings, fluorene rings, indole rings, carbazole rings, benzofuran rings, dibenzofuran rings, benzothiophene rings, dibenzothiophene rings, dibenzoselenene rings, cyclopentadiene rings, furan rings, thiophene rings, and thiophene rings.

4. The organic electroluminescent device as described in claim 3, wherein, Y is selected from B, P=O, or P=S; Preferably, Y is B.

5. The organic electroluminescent device as described in claim 4, wherein, In Equation 1, Y is B, and at least two of the four groups formed by X2 and X3, X4 and X5, X6 and X7, and X8 and X1 are selected from CR. x And the two sets of R x Connect them separately to form a loop; Preferably, the first compound has a structure represented by formula 2-1 or formula 2-2: Among them, T1 to T 17 Each occurrence is either identical or different and is selected from CR or N; 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 aroxy groups having 6-30 carbon atoms, and substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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; And there exists at least one substituent R that is R a The R a 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; Adjacent substituents R, R a They can be arbitrarily connected to form a ring.

6. The organic electroluminescent device as described in claim 2, wherein, R', R, 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 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, cyano groups, and combinations thereof. Adjacent substituents R, R x They can be arbitrarily connected to form a loop; Preferably, the R', R, 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 aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, cyano groups, and combinations thereof.

7. The organic electroluminescent device as described in claim 2, wherein, The LUMO level of the first compound is less than or equal to -2.92 eV; Preferably, the LUMO energy level of the first compound is less than or equal to -2.95 eV.

8. The organic electroluminescent device as described in claim 2, wherein, The first compound is selected from the group consisting of compounds ET-1 to ET-203: Where Cz represents the structure Optionally, the hydrogen in the structure of compounds ET-1 to ET-203 may be partially or completely replaced by deuterium.

9. The organic electroluminescent device as described in claim 2, wherein, The light-emitting layer comprises at least one light-emitting material, wherein the light-emitting material is a fluorescent light-emitting material; Preferably, the luminescent material has a structure represented by one of Formulas 3 to 8: In Equations 3 to 8, Y is selected from N or CR each time it appears, either the same or different. y ; R y Each time it appears, it is selected from the group consisting of the same or different elements: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 ring 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 alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted... Alkynyl 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 alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium 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; Adjacent substituent R y They can be arbitrarily connected to form a loop; More preferably, R y At least one of them is selected from deuterium, substituted or unsubstituted alkyl groups having 1-20 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 amino groups having 0-20 carbon atoms, and combinations thereof. Most preferably, the luminescent material is selected from the group consisting of compounds BD1 to BD27:

10. The organic electroluminescent device as described in claim 2, wherein, The first organic layer is an electron transport layer.

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