An organic electroluminescent device

Abstract

Disclosed is an organic electroluminescent device. The organic electroluminescent device is a top-emitting device comprising a first organic layer and a second organic layer disposed between a first electrode having high reflectivity and a semi-transparent or transparent second electrode, the first organic layer being disposed between the first electrode and the second organic layer and being in direct contact with the second organic layer, the first organic layer having a thickness less than 50 nm and comprising a first organic material, the second organic layer being a light-emitting layer and comprising at least one host material, the host material having a structure represented by Formula 1. The novel top-emitting device exhibits higher device efficiency and longer lifetime, with better device performance. In addition, a display assembly is also disclosed.

Description

Technical Field

[0001] This invention relates to organic electronic devices, such as organic electroluminescent devices. More particularly, it relates to a top-emitting organic electroluminescent device comprising a first organic layer and a second organic layer. Background Technology

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

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a bilayer organic electroluminescent device comprising an arylamine hole transport layer and a tri-8-hydroxyquinoline-aluminum layer as both an electron transport layer and a light-emitting 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 light-emitting 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 fabrication on flexible substrates.

[0004] OLEDs can be classified 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). 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 transition from triplet to singlet states. 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] OLED device structures typically include a cathode, an anode, and a series of organic functional layers disposed between the anode and cathode. These mainly include: a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). The HTL is usually composed of a hole transport material (HTM) with a shallow HOMO level. The emissive layer generally consists of at least one host material and at least one luminescent material. Typically, the HOMO level of the host material in the emissive layer is deeper than that of the HTM, resulting in a higher potential barrier during hole transport from the HTL to the EML, which significantly affects device performance. To address this issue, a common practice is to place a second hole transport layer (HTL2, also known as a prime layer or electron blocking layer EBL) between the HTL and EML, using an organic material in HTL2 with a HOMO level between the HTM and the host material.

[0009] In the top-emitting (TE) device structure most commonly used in display applications, the microcavity effect needs to be adjusted to achieve higher efficiency. This typically involves using a relatively thick first hole transport layer (HTL1) and a second hole transport layer (HTL2). For example, the total thickness of HTL1 and HTL2 in a red top-emitting device is generally around 200 nm. Since the HOMO energy level of the hole transport material in HTL1 is lower, the thickness of HTL1 is usually larger, for example, around 120 nm. Thus, the thickness of HTL2 is generally around 60-80 nm. On the other hand, a significant potential barrier may still exist between HTL2 and the EML. However, if a material with a deeper HOMO energy level is chosen to form HTL2, such as a material with a HOMO energy level close to that of the host material, the hole barrier from HTL1 to HTL2 will increase, making carrier transitions more difficult. Furthermore, materials with deeper energy levels typically have lower hole mobility, and the thickness of HTL2 remains relatively large. These factors can lead to increased device voltage and even reduced device efficiency and shorter lifetime. Therefore, further research is needed on optimizing the structure of top-emitting devices. Summary of the Invention

[0010] This invention aims to provide a novel top-emitting device to solve at least some of the aforementioned problems. The top-emitting device includes a first organic layer and a second organic layer disposed between a first electrode and a second electrode. The first organic layer is disposed between the first electrode and the second organic layer and is in direct contact with the second organic layer. The thickness of the first organic layer is less than 50 nm and contains a first organic material. The second organic layer is a light-emitting layer and contains at least one host material, the at least one host material having a structure represented by Formula 1. Research has shown that introducing a thin first organic layer (buffer layer) containing the first organic material between the first electrode and the light-emitting layer containing a specific host material facilitates the transport of holes from a second hole transport layer to the buffer layer and then to the light-emitting layer. Furthermore, due to the small thickness of the buffer layer, even a low mobility in a deep-level buffer layer does not significantly affect the voltage. Simultaneously, it was found that using a host material with a relatively shallow energy level for the host material of the light-emitting layer better matches the buffer layer, resulting in better device performance. The novel top-emitting device exhibits higher device efficiency and longer lifetime, demonstrating superior device performance.

[0011] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0012] substrate;

[0013] A first electrode disposed on a substrate;

[0014] A second electrode is disposed above the first electrode;

[0015] An organic layer disposed between the first electrode and the second electrode;

[0016] The first electrode has high reflectivity, and the second electrode is translucent or transparent;

[0017] The organic layer includes a first organic layer and a second organic layer. The first organic layer is disposed between the first electrode and the second organic layer and is in direct contact with the second organic layer, while the first organic layer is not in direct contact with the first electrode.

[0018] The first organic layer comprises a first organic material, and the thickness of the first organic layer is less than 50 nm;

[0019] The first organic material comprises one or more chemical structural units selected from the group consisting of: triarylamines, carbazole, fluorene, dibenzofuran, dibenzothiophene, and combinations thereof;

[0020] The second organic layer is a light-emitting layer and contains at least one host material;

[0021] The at least one main material has a structure represented by Equation 1:

[0022]

[0023] In Formula 1, A1, A2 and A3 are selected from N or CR each time they appear, and rings A, B and C are selected from carbon rings with 5-18 carbon atoms or heterocycles with 3-18 carbon atoms each time they appear.

[0024] R x Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted.

[0025] E has a structure represented by Equation 2:

[0026] ,

[0027] In Formula 2, Ar is selected, either identically or differently, from substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms.

[0028] Z1 to Z3 are each independently selected from N or CR z And at least one of Z1 to Z3 is N;

[0029] L has a structure represented by Equation 3:

[0030]

[0031] In Equation 3, ring D is selected from carbon rings having 5-18 carbon atoms or heterocycles having 3-18 carbon atoms each time it appears;

[0032] R n Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted.

[0033] L1 is selected from a single bond, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, or a combination thereof; and when L1 is selected from a substituted aryl group having 6-30 carbon atoms or a substituted heteroaryl group having 3-30 carbon atoms, L1 has a substituent R. m ;R m The same or different occurrences each time indicate single or multiple substitution;

[0034] R, R x R z R n R mEach time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0035] Adjacent substituents R, R x They can be arbitrarily connected to form a loop;

[0036] Adjacent substituent R n R m They can be arbitrarily connected to form a ring.

[0037] According to another embodiment of the present invention, a display component is also disclosed, which includes an organic electroluminescent device as shown in the above embodiments.

[0038] The novel top-emitting device disclosed in this invention includes a first organic layer and a second organic layer disposed between a first electrode and a second electrode. The first organic layer is in direct contact with the second organic layer and contains a first organic material. The second organic layer is a light-emitting layer and contains at least one host material, the host material having a structure represented by Formula 1. The novel top-emitting device exhibits higher device efficiency and longer lifetime, resulting in better device performance. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a typical bottom-emitting OLED device.

[0040] Figure 2 This is a schematic diagram of another typical bottom-emission OLED device.

[0041] Figure 3 This is a schematic diagram of a typical top-emitting OLED device.

[0042] Figure 4 This is a schematic diagram of the structure of a top-emitting OLED device having the first organic layer disclosed herein. Detailed Implementation

[0043] OLEDs can be manufactured on various substrates, such as glass, plastic, and metal. Figure 1 A typical bottom-emission OLED 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.

[0044] Each of these layers has numerous examples. For instance, U.S. Patent No. 5,844,363, incorporated herein by reference in its entirety, discloses a flexible and transparent substrate-anode combination. 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, 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., 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, incorporated herein by reference in its entirety. Examples of cathodes are disclosed in U.S. Patents Nos. 5,703,436 and 5,707,745, incorporated herein by reference in their entirety. 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, both incorporated herein by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, 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, also incorporated herein by reference in its entirety.

[0045] 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.

[0046] 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.

[0047] OLEDs also require an encapsulation layer, such as Figure 2 This schematic, non-limiting illustration shows another typical bottom-emission OLED device 200, which, along with... 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.

[0048] 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.

[0049] The materials and structures described in this article can also be used in other organic electronic devices listed above.

[0050] 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.

[0051] 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.

[0052] As used in this article, "average transmittance in the visible light region" refers to the sum of transmittance in the wavelength range of 380 nm to 780 nm divided by the number of test points. For example, if one point is taken for every 1 nm, then the number of test points is 401; if one point is taken for every 2 nm, then the number of test points is 200.

[0053] 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.

[0054] 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).

[0055] 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.

[0056] 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).

[0057] In this paper, the HOMO (highest occupied orbital) and LUMO (lowest unoccupied orbital) energy levels were determined using electrochemical cyclic voltammetry. The electrochemical cyclic voltammetry was performed 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 DCM was used as the solvent, and 0.1 mol / L tetrabutylammonium hexafluorophosphate was used as the supporting electrolyte to prepare a 10...-3 The solution was prepared at mol / L, and nitrogen gas was introduced 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, and test window -1 V to 1 V.

[0058] In this paper, all "HOMO levels" and "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 HOMO level in the buffer layer is less than -5.2 eV" means that the HOMO level in the buffer layer is numerically more negative than -5.2 eV; for example, the HOMO level of the buffer layer is -5.26 eV.

[0059] Definition of the term "substituent group"

[0060] Halogens or halides – as used herein, include fluorine, chlorine, bromine, and iodine.

[0061] 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.

[0062] Cycloalkyl – As used herein, it 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.

[0063] 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.

[0064] 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.

[0065] Alkynyl – As used herein, this term 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.

[0066] 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, phenanthrene, fluorene, pyrene, phenylene oxide, perylene oxide, and azurite, with phenyl, biphenyl, terphenyl, triphenylene, fluorene, and naphthalene being preferred. 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'-methylbiphenyl, 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.

[0067] Heterocyclic groups or heterocycles – as used herein, non-aromatic cyclic groups are considered. 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] Arylalkyl – As used herein, this 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.

[0072] Alkylsilyl – As used herein, this 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. Additionally, the alkylsilyl group may optionally be substituted.

[0073] 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.

[0074] Alkylgermanium group – As used herein, this 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. Additionally, the alkylgermanium group may optionally be substituted.

[0075] Arylgermanium – As used herein, this 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.

[0076] 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.

[0077] In this disclosure, unless otherwise defined, the term "substituted alkyl," "substituted cycloalkyl," "substituted heteroalkyl," "substituted heterocyclic," "substituted aralkyl," "substituted alkoxy," "substituted aryloxy," "substituted alkenyl," "substituted alkynyl," "substituted aryl," "substituted heteroaryl," "substituted alkylsilyl," "substituted arylsilyl," "substituted alkylgermanium," "substituted arylgermanium," "substituted amino," "substituted acyl," "substituted carbonyl," and "substituted carboxylic acid" are used interchangeably. 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 group, sulfinyl, sulfonyl, and phosphinyl. One or more groups can be selected from deuterium, halogen, unsubstituted alkyl groups having 1-20 carbon atoms, and unsubstituted alkyl groups having... Cycloalkyl groups with 3-20 carbon atoms, unsubstituted heteroalkyl groups with 1-20 carbon atoms, unsubstituted heterocyclic groups with 3-20 carbon atoms, unsubstituted aralkyl groups with 7-30 carbon atoms, unsubstituted alkoxy groups with 1-20 carbon atoms, unsubstituted aryloxy groups with 6-30 carbon atoms, unsubstituted alkenyl groups with 2-20 carbon atoms, unsubstituted alkynyl groups with 2-20 carbon atoms, and unsubstituted aryl groups with 6-30 carbon atoms. Unsubstituted heteroaryl groups having 3-30 carbon atoms, unsubstituted alkylsilyl groups having 3-20 carbon atoms, unsubstituted arylsilyl groups having 6-20 carbon atoms, unsubstituted alkylgermanium groups having 3-20 carbon atoms, unsubstituted arylgermanium groups having 6-20 carbon atoms, and unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphine, and combinations thereof having 0-20 carbon atoms.

[0078] It should be understood that when a molecular fragment is described as a substituent or otherwise attached to another part, its name may be written according to whether it is a fragment (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 fragments are considered equivalent.

[0079] 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.

[0080] In the compounds mentioned in this disclosure, polysubstituted means including disubstituted, up to the maximum range of available substitutions. When a substituent in a compound mentioned in this disclosure represents polysubstituted (including disubstituted, trisubstituted, tetrasubstituted, 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.

[0081] 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.

[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 the same carbon atom connecting to each other via chemical bonds to form a ring, as exemplified by the following formula:

[0083] .

[0084] 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:

[0085] .

[0086] 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:

[0087] .

[0088] 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:

[0089] .

[0090] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0091] substrate;

[0092] A first electrode disposed on a substrate;

[0093] A second electrode is disposed above the first electrode;

[0094] An organic layer disposed between the first electrode and the second electrode;

[0095] The first electrode has high reflectivity, and the second electrode is translucent or transparent;

[0096] The organic layer includes a first organic layer and a second organic layer. The first organic layer is disposed between the first electrode and the second organic layer and is in direct contact with the second organic layer, while the first organic layer is not in direct contact with the first electrode.

[0097] The first organic layer comprises a first organic material, and the thickness of the first organic layer is less than 50 nm;

[0098] The first organic material comprises one or more chemical structural units selected from the group consisting of: triarylamines, carbazole, fluorene, dibenzofuran, dibenzothiophene, and combinations thereof;

[0099] The second organic layer is a light-emitting layer and contains at least one host material;

[0100] The at least one main material has a structure represented by Equation 1:

[0101]

[0102] In Formula 1, A1, A2 and A3 are selected from N or CR each time they appear, and rings A, B and C are selected from carbon rings with 5-18 carbon atoms or heterocycles with 3-18 carbon atoms each time they appear.

[0103] R x Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted.

[0104] E has a structure represented by Equation 2:

[0105] ,

[0106] In Formula 2, Ar is selected, either identically or differently, from substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms.

[0107] Z1 to Z3 are each independently selected from N or CR z And at least one of Z1 to Z3 is N;

[0108] L has a structure represented by Equation 3:

[0109]

[0110] In Equation 3, ring D is selected from carbon rings having 5-18 carbon atoms or heterocycles having 3-18 carbon atoms each time it appears;

[0111] R n Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted.

[0112] L1 is selected from a single bond, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, or a combination thereof; and when L1 is selected from a substituted aryl group having 6-30 carbon atoms or a substituted heteroaryl group having 3-30 carbon atoms, L1 has a substituent R. m ;R m The same or different occurrences each time indicate single or multiple substitution;

[0113] R, R x R z R n R m Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0114] Adjacent substituents R, R x They can be arbitrarily connected to form a loop;

[0115] Adjacent substituent R n R m They can be arbitrarily connected to form a ring.

[0116] In this embodiment, adjacent substituents R, R x The ability to optionally connect to form a ring is intended to indicate that adjacent substituents R can optionally connect to form a ring, and also to indicate that when there are multiple R on ring A. x When, the adjacent substituent R x It can be arbitrarily connected to form a loop, and is also intended to indicate that when there are multiple R on the loop B. x When, the adjacent substituent R x The ability to arbitrarily connect to form a loop is also intended to indicate the presence of multiple Rs on the loop C. x When, the adjacent substituent R x The elements can be optionally linked to form a ring, and are also intended to represent adjacent substituents R and R'. x They can be optionally linked to form a ring; obviously, to those skilled in the art, adjacent substituents R, R x Alternatively, they may not connect to form a ring. In this case, adjacent substituents R do not connect to form a ring, and / or adjacent substituents R x It also does not connect to form a ring, and / or adjacent substituents R and R x They also do not connect to form a loop.

[0117] In this paper, adjacent substituents R n R m The ability to optionally connect to form a ring is intended to indicate the presence of a substituent R. n R m When, adjacent substituent groups, such as adjacent substituent R n Between, adjacent substituents R m Between, substituent R n With R m Between these substituent groups, any one or more can connect to form a ring. It is obvious that when substituent R is present... n R m In this case, adjacent substituent groups may not be connected to form a ring.

[0118] According to one embodiment of the present invention, in Formula 1, rings A, B and C are selected from five-membered carbon rings, aromatic rings having 6-18 carbon atoms, or heteroaromatic rings having 3-18 carbon atoms each time they appear.

[0119] According to one embodiment of the present invention, in Formula 1, rings A, B, and C are selected from 5-membered carbon rings, benzene rings, 5-membered heteroaromatic rings, or 6-membered heteroaromatic rings each time they appear.

[0120] According to one embodiment of the present invention, the main material has a structure represented by formula 1-a:

[0121]

[0122] A1 to A3 are selected from N or CR each time they appear, either identically or differently, and X1 to X... 10 Each occurrence is either identically or differently selected from N or CR x ;

[0123] 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 groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0124] Adjacent substituents R, R x They can be arbitrarily connected to form a ring.

[0125] In this paper, adjacent substituents R, R x The ability to optionally connect to form a ring is intended to indicate that adjacent substituents R can optionally connect to form a ring, and also to indicate that adjacent substituents R in X1 to X3... x The elements can be optionally linked to form a ring, and are also intended to represent adjacent substituents R in X4 to X6. x They can be optionally connected to form a loop, and are also intended to represent X7 to X. 10 adjacent substituents R x The elements can be optionally linked to form a ring, and are also intended to represent adjacent substituents R and R'. x They can be optionally connected to form a loop, for example, between A1 and X3, and / or between A3 and X. 10 Either X6 and X7 can be optionally linked to form a ring; obviously, to those skilled in the art, adjacent substituents R, R xAlternatively, they may not connect to form a ring. In this case, adjacent substituents R do not connect to form a ring, and / or adjacent substituents R x It also does not connect to form a ring, and / or adjacent substituents R and R x They also do not connect to form a loop.

[0126] According to one embodiment of the present invention, wherein E has the structure shown in Formula 2:

[0127]

[0128] Among them, Z1 to Z3 are each independently selected from N or CR. z And at least two of Z1 to Z3 are N;

[0129] Among them, R z Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alksilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, cyano, isocyano, hydroxyl, mercapto groups having 0-20 carbon atoms, and combinations thereof.

[0130] Ar is selected, in the same or different ways, from substituted or unsubstituted aryl groups having 6-18 carbon atoms, or from substituted or unsubstituted heteroaryl groups having 3-18 carbon atoms.

[0131] According to one embodiment of the present invention, Z1 to Z3 are all N.

[0132] According to one embodiment of the invention, Ar is selected from the group consisting of phenyl, deuterated phenyl, methyl phenyl, fluorophenyl, tert-butylphenyl, trideuterated methylphenyl, biphenyl, naphthyl, deuterated naphthyl, dibenzofuranyl, dibenzothiopheneyl, 9,9-dimethylfluorenyl, carbazolyl, pyridyl, pyrimidinyl, 4-cyanophenyl, 3-cyanophenyl, triphenylene, and combinations thereof, each time Ar appears.

[0133] According to one embodiment of the present invention, E is selected from the group consisting of E-1 to E-54. The specific structures of E-1 to E-54 are as follows:

[0134] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0135] According to one embodiment of the present invention, wherein the L has the structure shown in Formula 3:

[0136]

[0137] In this context, ring D, each time it appears, is selected from an aromatic ring having 6-18 carbon atoms, or a heteroaromatic ring having 3-18 carbon atoms; R n R mEach time it appears, it is selected from the group consisting of, either identically or differently, hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted aryloxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alksilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, cyano, isocyano, hydroxyl, mercapto groups having 0-20 carbon atoms, and combinations thereof; adjacent substituent R n R m They can be arbitrarily connected to form a ring.

[0138] According to one embodiment of the present invention, wherein the ring D, each time it appears, is selected from the same or different groups of benzene ring, naphthalene ring, phenanthrene ring, fluorene ring, triphenylene ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, pyridine ring, and combinations thereof;

[0139] The L1 is selected from single bonds, substituted or unsubstituted phenylene, or substituted or unsubstituted naphthylene;

[0140] R n R m 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 aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted amino, cyano, hydroxyl, mercapto groups having 0-20 carbon atoms, and combinations thereof.

[0141] According to one embodiment of the present invention, L1 is selected from single bonds.

[0142] According to one embodiment of the present invention, L is selected from the group consisting of L-1 to L-20. The specific structures of L-1 to L-20 are as follows:

[0143] , , , , , , , , , , , , , , , , , , , ;

[0144] In the structures L-1 to L-20, "*" indicates the position where the structure is connected to the N atom in Formula 1. "" indicates the position where the structure is connected to the E structure.

[0145] According to one embodiment of the present invention, the hydrogen in the structures of L-1 to L-20 is partially or completely replaced by deuterium.

[0146] According to one embodiment of the present invention, the host material is selected from the group consisting of compounds 1 to 41. The specific structures of compounds 1 to 41 are as follows:

[0147] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0148] According to one embodiment of the present invention, the hydrogen in compounds 1 to 41 can be partially or completely replaced by deuterium.

[0149] According to one embodiment of the present invention, the energy level difference between the HOMO energy level of the first organic material and the HOMO energy level of the host material is less than 0.25 eV.

[0150] According to one embodiment of the present invention, the energy level difference between the HOMO energy level of the first organic material and the HOMO energy level of the host material is less than 0.2 eV.

[0151] According to one embodiment of the present invention, the energy level difference between the HOMO energy level of the first organic material and the HOMO energy level of the host material is less than 0.15 eV.

[0152] According to one embodiment of the present invention, the HOMO energy level of the first organic material is less than -5.2 eV.

[0153] According to one embodiment of the present invention, the HOMO energy level of the first organic material is less than -5.25 eV.

[0154] According to one embodiment of the present invention, the first organic material has a structure represented by Formula 4:

[0155]

[0156] In Equation 4,

[0157] Each time Y1 to Y8 appears, it is selected from CR1 or N in the same or different ways;

[0158] L2, each time it appears, is selected from the same or different substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof;

[0159] Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, either in the same or different manner.

[0160] R1, each time appearing, is selected from the group consisting of, either identically or differently from, hydrogen, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryl group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms;

[0161] Adjacent substituents R1 can optionally connect to form a ring.

[0162] In this document, adjacent substituents R1 can optionally connect to form a ring, which is intended to indicate that any two adjacent substituents R1 can connect to form a ring. Obviously, any two adjacent substituents R1 can also not connect to form a ring.

[0163] According to one embodiment of the present invention, the L2 is selected from substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, or combinations thereof.

[0164] According to one embodiment of the present invention, wherein the L2 is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted fluorene, substituted or unsubstituted silylfluorene, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dibenzoselenophenyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted terphenylene, substituted or unsubstituted pyridyl, substituted or unsubstituted spirodifluorene, substituted or unsubstituted anthracene, substituted or unsubstituted pyrene, or combinations thereof.

[0165] According to one embodiment of the present invention, wherein the L2 is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted fluorene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiopheneyl, substituted or unsubstituted phenanthylene, substituted or unsubstituted anthraceneylene, and substituted or unsubstituted pyreneylene.

[0166] According to one embodiment of the present invention, the L2 is selected from phenylene, biphenylene, terphenylene, naphthylene, phenanthrene, dibenzofuranylene, dimethylfluorene, diphenylfluorene or spirofluorene.

[0167] According to one embodiment of the invention, wherein R1 is selected from the group consisting of the same or different each time it appears: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl group having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3-20 cyclic carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, and substituted or unsubstituted heteroaryl group having 3-30 carbon atoms.

[0168] According to one embodiment of the invention, wherein R1 is selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, and combinations thereof, each time it appears.

[0169] According to one embodiment of the present invention, wherein Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-20 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms.

[0170] According to one embodiment of the present invention, wherein Ar1 and Ar2, each time they appear, are selected from phenyl, 4-tert-butylphenyl, 4-diphenylaminophenyl, phenylnaphthyl, biphenyl, terphenyl, naphthyl, phenanthryl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9,9-spirodifluorenyl, pyridyl or pyrimidinyl.

[0171] According to one embodiment of the present invention, the first organic material is selected from the group consisting of compounds C1 to C57. The specific structures of compounds C1 to C57 are as follows:

[0172] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0173] According to one embodiment of the present invention, the thickness of the first organic layer is less than 30 nm.

[0174] According to one embodiment of the present invention, the thickness of the first organic layer is less than 20 nm.

[0175] According to one embodiment of the present invention, the thickness of the first organic layer is less than 10 nm.

[0176] According to one embodiment of the present invention, the first electrode has an average reflectivity greater than 70% in the visible light region.

[0177] According to one embodiment of the present invention, the first electrode has an average reflectivity greater than 80% in the visible light region.

[0178] According to one embodiment of the present invention, the first electrode has an average reflectivity greater than 85% in the visible light region.

[0179] According to one embodiment of the present invention, the average transmittance of the second electrode in the visible light region is greater than 15%.

[0180] According to one embodiment of the present invention, the average transmittance of the second electrode in the visible light region is greater than 20%.

[0181] According to one embodiment of the present invention, the average transmittance of the second electrode in the visible light region is greater than 25%.

[0182] According to one embodiment of the present invention, the first electrode is selected from the group consisting of Ag, Al, Ti, Cr, Pt, Ni, TiN, and combinations of the above materials with ITO and / or MoOx (molybdenum oxide);

[0183] The second electrode is selected from the group consisting of the following materials: MgAg alloy, MoOx, Yb, Ca, ITO, IZO, or a combination thereof.

[0184] According to one embodiment of the present invention, the system further includes a third organic layer and a fourth organic layer, wherein the third organic layer comprises a third organic material and the fourth organic layer comprises a fourth organic material. In this embodiment, the third organic material and the fourth organic material may be the same or different.

[0185] According to one embodiment of the present invention, the sum of the thicknesses of the third organic layer and the fourth organic layer is greater than or equal to 100 nm.

[0186] According to one embodiment of the present invention, the sum of the thicknesses of the third organic layer and the fourth organic layer is greater than or equal to 120 nm.

[0187] According to one embodiment of the present invention, the sum of the thicknesses of the third organic layer and the fourth organic layer is greater than or equal to 150 nm.

[0188] According to one embodiment of the present invention, the sum of the thicknesses of the third organic layer and the fourth organic layer is greater than or equal to 180 nm.

[0189] According to one embodiment of the present invention, the HOMO energy levels of the third organic material and the fourth organic material are both greater than the HOMO energy level of the first organic material.

[0190] According to one embodiment of the present invention, the third organic layer and the fourth organic layer are disposed between the first electrode and the first organic layer, and the third organic layer and the fourth organic layer are in direct contact, and the fourth organic layer is in direct contact with the first organic layer.

[0191] According to one embodiment of the present invention, in the electroluminescent device, the second organic layer further comprises at least one phosphorescent material.

[0192] According to one embodiment of the present invention, in the electroluminescent device, the phosphorescent material is a metal complex, and the metal complex has M(L) a ) m (L b ) n (L c ) q The general formula;

[0193] M is selected from metals with a relative atomic mass greater than 40;

[0194] L a L b L c These are the first, second, and third ligands that coordinate with M, respectively; L a L b L c They can be optionally linked to form polydentate ligands; for example, L a L b and L c Any two of them can be connected to form a tetradentate ligand; for example, L a L b and L c They can connect to form hexadecantal ligands; or, for example, L a L b L c They are not connected and therefore do not form multidentate ligands;

[0195] L a L b L c They can be the same or different; m is 1, 2 or 3; n is 0, 1 or 2; q is 0 or 1; the sum of m, n, and q equals the oxidation state of M; when m is greater than or equal to 2, multiple L a They can be the same or different; when n is 2, the two Ls b They can be the same or different;

[0196] L a It has the structure shown in Equation 5:

[0197] ;

[0198] in,

[0199] Ring E is selected from a 5-membered heteroaryl ring or a 6-membered heteroaryl ring;

[0200] Ring F is selected from a 5-membered unsaturated carbon ring, a benzene ring, a 5-membered heteroaromatic ring, or a 6-membered heteroaromatic ring;

[0201] Rings E and F are connected via Y a and Y b Condensation;

[0202] Y a and Y b Each occurrence is either identical or different and is selected from C or N;

[0203] R d1 R e1 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0204] U1-U4 are selected from CR each time they appear, either in the same or different ways. xx Or N;

[0205] R d1 R e1 R xx Each time it appears, it is selected from the group consisting of, 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 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0206] Adjacent substituent R d1 R e1 R xx They can be arbitrarily connected to form a ring;

[0207] L b L c Each can be independently selected from any of the following structures:

[0208] , , , , , , , , , , , ,

[0209] in,

[0210] R a R b and R c Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0211] X b Each time it appears, choose from the following groups, either the same or different: O, S, Se, NR N1 and CR C1 R C2 ;

[0212] X c and X d Each time it appears, choose from the following groups, either the same or different: O, S, Se, and NR. N2 ;

[0213] R a R b R c R N1 R N2 R C1 and R C2 Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 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, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms;

[0214] The ligand L b L c In the structure, adjacent substituents R a R b R c R N1 R N2 R C1 and R C2 They can be arbitrarily connected to form a ring.

[0215] In this paper, adjacent substituents R d1 R e1 R xx The ability to optionally link into rings is intended to indicate the presence of substituent R. d1 Substituent R e1 Substituent R xx When, adjacent substituent groups, such as adjacent substituent R d1 Substituents R between and adjacent e1 Substituents R between and adjacent xx Substituents R between and adjacent d1 With R e1 Substituents R between and adjacent d1 With R xx Between and adjacent substituents R e1 With R xx Between these adjacent substituent groups, any one or more can connect to form a ring. It is obvious that when substituent R is present... d1 Substituent R e1 Substituent R xx At the same time, these substituent groups may not be connected to form a ring.

[0216] In this embodiment, adjacent substituents R a R b R c R N1 R N2 R C1 and R C2 They can be optionally linked to form a ring, intended to represent adjacent substituent groups, for example, two substituents R a Between the two substituents R b Between the two substituents R c Between, substituent R a and R b Between, substituent R a and R c Between, substituent R b and R c Between, substituent R a and RN1 Between, substituent R b and R N1 Between, substituent R a and R C1 Between, substituent R a and R C2 Between, substituent R b and R C1 Between, substituent R b and R C2 Between, substituent R a and R N2 Between, substituent R b and R N2 Between, and R C1 and R C2 Between these substituents, any one or more of these substituent groups can connect to form a ring. Obviously, these substituents can also not connect to form a ring.

[0217] According to another embodiment of the present invention, a display component 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.

[0218] Combination with other materials

[0219] 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.

[0220] Materials described herein for use in specific layers in 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, barrier layers, injection 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. For example, in the organic electroluminescent devices disclosed herein, the light-emitting layer can typically, but not limitedly, comprise phosphorescent materials such as:

[0221] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0222] In the embodiments of the device, the characteristics of the device are also tested using conventional equipment in the art (including but not limited to vapor deposition machines manufactured by Angstrom Engineering, optical testing systems and lifetime testing systems manufactured by Suzhou Fushida, ellipsometers manufactured by Beijing Liangtuo, etc.) and methods well known to those skilled in the art. Since those skilled in the art are familiar with the use of the above-mentioned equipment, testing methods, and other related content, and can obtain the inherent data of the sample reliably and unaffected, the above-mentioned related content will not be elaborated in this patent.

[0223] A typical top-emitting OLED device structure is as follows: Figure 3As shown in the diagram. The OLED device 300 includes: an anode layer 301, a hole injection layer (HIL) 302, a first hole transport layer (HTL1) 303, a second hole transport layer (HTL2) 304 (also called a prime layer), an emissive layer (EML) 305, a hole blocking layer (HBL) 306 (the hole blocking layer 306 is optional), an electron transport layer (ETL) 307, an electron injection layer (EIL) 308, a cathode layer 309, and a capping layer 310. The anode layer 101 is a material or combination of materials with high reflectivity, including but not limited to Ag, Al, Ti, Cr, Pt, Ni, TiN, and combinations of the above materials with ITO and / or MoOx (molybdenum oxide). Typically, the anode's reflectivity is greater than 50%; preferably, it is greater than 70%; more preferably, it is greater than 80%. The cathode layer 109 should be a translucent or transparent conductive material, including but not limited to MgAg alloy, MoOx, Yb, Ca, ITO, IZO, or combinations thereof, with an average transmittance of greater than 15% for light in the visible region; preferably, it is greater than 20%; more preferably, it is greater than 25%. The hole injection layer 102 can be a single material layer, such as the commonly used HATCN; the hole injection layer 102 can also be a hole transport material doped with a certain proportion of p-type conductive dopant, typically not exceeding 5%, and commonly between 1% and 3%. The second hole transport layer (HTL2) is optional, but a dual-hole transport layer device structure is typically used for better energy level matching with the host material. The HOMO level of HTL2 is generally slightly deeper than that of HTL1; for example, the HOMO level of HTL1 is commonly -5.09 eV, while that of HTL2 is -5.10 eV. The total thickness of the hole transport layers is typically between 100 nm and 200 nm. Due to the microcavity effect in top-emitting devices, the microcavity is usually adjusted by controlling the thickness of the first or second hole transport layer. For example, to optimize the microcavity effect of a top-emitting OLED device, i.e., to maximize current efficiency, the common practice is to fix the thickness of either HTL1 or HTL2 and adjust the thickness of the other layer to control the microcavity. A preferred approach is to fix the thickness of HTL1 and then adjust the thickness of HTL2 to control the microcavity. Those skilled in the art will readily understand that for two top-emitting devices, if their only difference is the material used in one of the organic layers of the device, for example, using a different organic material only in HTL2 (while the other functional layers are the same), then the optimal microcavity length of the two top-emitting devices may have a slight difference because the refractive index of the different organic materials in HTL2 may be slightly different.

[0224] In this invention, we propose inserting a first organic layer (buffer layer, BFL) between the hole transport layer (HTL) and the light-emitting layer (EML) of a top-emitting device (TE) to optimize device performance. Such a top-emitting device structure can be implemented as follows: Figure 4 As shown in the diagram. The OLED device 400 includes: an anode layer 401, a hole injection layer (HIL) 402, a first hole transport layer (HTL1) 403, a second hole transport layer (HTL4) 404 (the second hole transport layer (HTL4) is optional), a buffer layer (BFL) 405, an emissive layer (EML) 406, a hole blocking layer (HBL) 407 (the hole blocking layer 407 is optional), an electron transport layer (ETL) 408, an electron injection layer (EIL) 409, a cathode layer 410, and a capping layer 411. The thickness of the buffer layer is less than 50 nm; preferably, the thickness of the buffer layer is less than 30 nm; more preferably, the thickness of the buffer layer is less than 20 nm; and even more preferably, the thickness of the buffer layer is less than 10 nm. Such a thin buffer layer (BFL) ensures that the voltage does not rise due to low hole mobility. Simultaneously, the HOMO energy level of the first organic material in the buffer layer should be between the HTL and EML, particularly, the difference between the HOMO energy level of the first organic material and the HOMO energy level of at least one host material in the EML is less than 0.25 eV; preferably, less than 0.2 eV; more preferably, less than 0.15 eV. The HOMO energy level of the buffer layer material is less than -5.2 eV, which is greater than the HOMO energy level of at least one host material in the EML. Furthermore, to further ensure good energy level matching, at least one host material in the luminescent layer preferably has a host compound with a suitable HOMO energy level.

[0225] The HOMO levels of some hole transport materials, buffer layer materials, and host materials were tested using electrochemical cyclic voltammetry. The tests were conducted using a CorrTest CS120 electrochemical workstation (manufactured by Wuhan CorrTest Instruments Co., Ltd.) with 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 DCM was used as the solvent, and 0.1 mol / L tetrabutylammonium hexafluorophosphate was used as the supporting electrolyte to prepare 10... -3 The solution was prepared at mol / L, and 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, and test window -1 V to 1 V. Relevant data are shown in Table 1.

[0226] Table 1. HOMO levels of some hole transport materials, buffer layer materials, and red light host materials.

[0227]

[0228] Device Examples

[0229] The present invention will be described in more detail below with reference to the following embodiments. The compounds used in the following embodiments are readily available to those skilled in the art, and their synthesis methods are not described in detail here. It will be apparent to those skilled in the art that the following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Based on the following embodiments, those skilled in the art can obtain other embodiments of the invention through modifications.

[0230] Example 1:

[0231] First, a 0.7 mm thick glass substrate was used, on which a pre-patterned indium tin oxide (ITO) 75 Å / Ag 1500 Å / ITO 150 Å layer was deposited as the anode. The 150 Å ITO deposited on the Ag layer here serves as a hole injection layer. The substrate was then dried in a glove box to remove moisture and placed on a support before being transferred to the vacuum chamber. The organic layer specified below was applied at a vacuum level of approximately 10... -6 Under Torr conditions, compounds were sequentially deposited on the anode via vacuum thermal evaporation at rates of 0.01–10 Å / s. First, compounds HT-1 and HT-2 were simultaneously deposited as hole injection layers (HIL, HT-1:HT-2 weight ratio 98:2, 100 Å). Compound HT-1 was then deposited on the HIL as the first hole transport layer (HTL1, 1200 Å). Next, compound HT-3 was deposited on the first hole transport layer as the second hole transport layer (HTL2, 600 Å). HTL2 also served as a microcavity conditioning layer, achieving the optimal microcavity length at a thickness of 600 Å. Subsequently, compound C38 was deposited as a buffer layer (BFL, 50 Å). Following this, compounds 1 and RD were deposited as light-emitting layers (EML, compound 1:RD weight ratio 98:2, 400 Å), and compound HB was deposited as a hole blocking layer (HBL, 50 Å). The device was first deposited with compound ET-1 and LiQ (8-hydroxyquinoline-lithium) as an electron transport layer (ETL, ET-1 to LiQ weight ratio 40:60, 350 Å), then 10 Å of metallic Yb was deposited as an electron injection layer (EIL), followed by simultaneous deposition of metallic silver (Ag) and magnesium (Mg) as a cathode (Cathode, silver to magnesium weight ratio 9:1, 140 Å), and finally, compound CPL54 was deposited as a cathode capping layer (CPL, 650 Å). Compound CPL54 was purchased from Jiangsu Sanyue Technology Co., Ltd. The device was then returned to the glove box and sealed with a glass cover to complete the device.

[0232] Example 2: The device implementation method of Example 2 is the same as that of Example 1, except that compound HT-4 is used instead of compound HT-3 in the second hole transport layer. The second hole transport layer also acts as a microcavity conditioning layer with a thickness of 600 Å, and the buffer layer material is C57 with a thickness of 50 Å.

[0233] Comparative Example 1: The device implementation of Comparative Example 1 is the same as that of Example 1, except that there is no buffer layer and the thickness of the second hole transport layer is adjusted to 650 Å to obtain the optimal microcavity.

[0234] Comparative Example 2: The device implementation method of Comparative Example 2 is the same as that of Example 1, except that the main material in the light-emitting layer is replaced with RH-2.

[0235] Comparative Example 3: The device implementation of Comparative Example 3 is the same as that of Comparative Example 1, except that the main material in the light-emitting layer is replaced with RH-2.

[0236] Comparative Example 4: The device implementation of Comparative Example 4 is the same as that of Example 2, except that there is no buffer layer and the thickness of the second hole transport layer is adjusted to 650 Å to obtain the optimal microcavity.

[0237] The detailed structure and thickness of some device layers are shown in the table below. The layers use more than one material; they are obtained by doping different compounds in the stated weight ratios.

[0238] Table 2. Partial device structures of the embodiments and comparative examples

[0239]

[0240] The structure of the compound used in the device is shown below:

[0241] , , , , , , , , , , .

[0242] Table 3 shows the device data for Examples 1, 2, and Comparative Examples 1-4. The color coordinates (CIE), voltage, and current efficiency (CE) are calculated at a current density of 10 mA / cm². 2 The measured device lifetime (LT97) is the time from the initial luminance of 5000 cd / m². 2 The time it takes for the decay to drop to 97% of its original value.

[0243] Table 3 Device Data

[0244]

[0245] In the device of Example 1, the HOMO energy level difference between the host material compound 1 and the buffer layer material is only 0.13 eV, while in Comparative Example 1, without a buffer layer, the energy level difference between HT-3 and the host material is 0.29 eV. The voltage of Example 1 is 3.8 V, consistent with Comparative Example 1; the CE of Example 1 is 78 cd / A, an improvement of 10% compared to Comparative Example 1; the lifetime of Example 1 is 5600 h, an improvement of 3.7% compared to Comparative Example 1. The addition of the buffer layer did not change the CIEx and CIEy of the device. Therefore, the addition of the buffer layer can effectively improve the efficiency and lifetime of the device. The host material used in Comparative Example 3 is RH-2, with a HOMO energy level of -5.09 eV and a HOMO energy level difference of 0.41 eV with the second hole transport layer. Due to the large energy level difference, the device performance is not as good as that of Example 1. The voltage of Example 1 is 0.6 V lower than that of Comparative Example 2, the CE is 16% higher, and the lifetime improvement is as high as 65%. This fully demonstrates the excellent performance of the organic electroluminescent device of the present invention.

[0246] In the device of Example 2, the energy level difference between the host material compound 1 and compound C57 in the buffer layer is only 0.12 eV, while in Comparative Example 4, which lacks a buffer layer, the HOMO energy level difference between compound 1 and the second hole transport layer is 0.25 eV, which is significantly larger. Therefore, the voltage of Example 2 is 0.1 V lower than that of Comparative Example 4. Furthermore, the efficiency of Example 2 is significantly improved compared to Comparative Example 4, increasing from 70 cd / A to 80 cd / A, an improvement of 14%. More importantly, the device lifetime of Example 2 is significantly improved by 22% on top of the already very long lifetime of Comparative Example 4. This further demonstrates the excellent performance of the organic electroluminescent device of the present invention.

[0247] In the devices of Comparative Examples 2 and 3, the host material was RH-2 with a HOMO level of -5.51 eV. The HOMO level of the host material is relatively deep, resulting in a large hole barrier between the BFL or HTL2 and the EML. Although Comparative Example 2 used compound C38 as the BFL, which lowered the barrier to some extent, the device performance of Comparative Example 2 did not achieve the expected improvement; the efficiency only increased slightly by 3%, but the voltage increased by 0.1 V, and the lifetime was significantly shortened by 38%. A comparison between Example 1 and Comparative Example 2 shows that Example 1 achieved a significant performance improvement because the HOMO levels of compound C38 in the BFL and compound 1 in the EML are more matched. From the above comparison, it can be seen that in the organic electroluminescent device of the present invention, because the first organic material as the BFL is more matched with the host material having the structure of Formula 1 in terms of energy level, it has superior performance.

[0248] In summary, the organic electroluminescent device of the present invention, by using a specific host material in the light-emitting layer and adding a first organic layer (buffer layer) composed of a specific material between the light-emitting layer and the hole transport layer, can effectively improve the efficiency and lifespan of the device.

[0249] To compare the effect of buffer layer thickness on device performance, we prepared Example 3 and Comparative Example 5. The implementation methods and data comparisons are as follows.

[0250] Example 3: The implementation method of Example 3 is the same as that of Example 1, except that Example 3 does not have a second hole transport layer, and the thickness of the first hole transport layer is adjusted to 180 nm to achieve the optimal microcavity length.

[0251] Comparative Example 5: The implementation method of Comparative Example 5 is the same as that of Example 3, except that the thickness of the BFL is adjusted to 700 Å and the thickness of the first hole transport layer is adjusted to 1150 Å to achieve the optimal microcavity length.

[0252] Table 4. Partial device structures of Example 3 and Comparative Example 5

[0253]

[0254] Table 5 shows the device data for Example 3 and Comparative Example 5. The color coordinates (CIE), voltage, and current efficiency (CE) are calculated at a current density of 10 mA / cm². 2 The following measurements were taken.

[0255] Table 5 Device Data

[0256]

[0257] As shown in Table 5, the device voltage in Example 3 is 3.9 V, while the device voltage in Comparative Example 5 increases to 6.3 V, representing a 62% increase; however, their device efficiencies are essentially the same. This demonstrates that device performance is highly sensitive to the thickness of the deep-level buffer layer; an excessively thick buffer layer will cause a dramatic increase in voltage, severely increasing the device's power consumption.

[0258] In summary, in the organic electroluminescent device of the present invention, a thin first organic layer containing a specific first organic material is introduced between the hole transport layer and the light-emitting layer containing the host material of the structure of Form 1. Since the host material in the light-emitting layer and the first organic material are more matched in energy level, superior device performance is achieved, especially the improvement in efficiency and lifetime, demonstrating the broad application prospects of the present invention.

[0259] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments and preferred embodiments described herein. Many of the materials and structures described herein can be substituted with other materials and structures without departing from the spirit of the invention. It should be understood that various theories regarding why the invention works are not intended to be limiting.

Claims

1. An organic electroluminescent device, comprising: substrate; A first electrode disposed on a substrate; A second electrode is disposed above the first electrode; An organic layer disposed between the first electrode and the second electrode; The first electrode has high reflectivity, and the second electrode is translucent or transparent; The organic layer includes a first organic layer and a second organic layer. The first organic layer is disposed between the first electrode and the second organic layer and is in direct contact with the second organic layer, while the first organic layer is not in direct contact with the first electrode. The first organic layer comprises a first organic material, and the thickness of the first organic layer is less than 30 nm; The first organic material comprises one or more chemical structural units selected from the group consisting of: triarylamines, carbazole, fluorene, spirofluorene, dibenzofuran, dibenzothiophene, and combinations thereof; The second organic layer is a light-emitting layer and contains at least one host material; The at least one main material has a structure represented by Formula 1-a: In Equation 1, A1, A2, and A3 are selected from N or CR each time they appear, either identically or differently, from X1 to X. 10 Each occurrence is either identically or differently selected from N or CR x ; R x Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted. E has a structure represented by Equation 2: ， In Formula 2, Ar is selected, either identically or differently, from substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms. Z1 to Z3 are all N; L has a structure represented by Equation 3: In Equation 3, ring D is selected from carbon rings having 5-18 carbon atoms or heterocycles having 3-18 carbon atoms each time it appears; R n Each occurrence, whether identical or different, indicates monosubstituted, polysubstituted, or unsubstituted. L1 is selected from a single bond, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, or a combination thereof; and when L1 is selected from a substituted aryl group having 6-30 carbon atoms or a substituted heteroaryl group having 3-30 carbon atoms, L1 has a substituent R. m ;R m The same or different occurrences each time indicate single or multiple substitution; R, R x R n R m Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted groups having 6-30 carbon atoms. Aryloxy groups, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Adjacent substituents R, R x They can be arbitrarily connected to form a loop; Adjacent substituent R n R m They can be arbitrarily connected to form a loop; The organic electroluminescent device is a top-emitting device; The HOMO energy level of the first organic material is less than -5.2 eV; The energy level difference between the HOMO energy level of the first organic material and the HOMO energy level of the host material is less than 0.25 eV; A hole transport layer is included between the first electrode and the light-emitting layer; The first organic layer is located between the hole transport layer and the light-emitting layer.

2. The organic electroluminescent device of claim 1, wherein E has the structure shown in Formula 2: in, Z1 to Z3 are all N; Ar is selected, in the same or different ways, from substituted or unsubstituted aryl groups having 6-18 carbon atoms, or from substituted or unsubstituted heteroaryl groups having 3-18 carbon atoms.

3. In the organic electroluminescent device of claim 2, Ar is selected from the group consisting of phenyl, deuterated phenyl, methyl phenyl, fluorophenyl, tert-butylphenyl, trideuterated methylphenyl, biphenyl, naphthyl, deuterated naphthyl, dibenzofuranyl, dibenzothiopheneyl, 9,9-dimethylfluorenyl, carbazoleyl, pyridyl, pyrimidinyl, 4-cyanophenyl, 3-cyanophenyl, triphenylene, and combinations thereof, each time Ar appears.

4. The organic electroluminescent device of claim 3, wherein E is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， 。 5. The organic electroluminescent device of claim 1, wherein the L has the structure shown in Formula 3: in, Ring D, each time it appears, is selected from an aromatic ring having 6-18 carbon atoms, or a heteroaromatic ring having 3-18 carbon atoms; R n R m Each time it appears, it is selected from the group consisting of, either identically or differently, hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted aryloxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alksilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, cyano, isocyano, hydroxyl, mercapto groups having 0-20 carbon atoms, and combinations thereof; adjacent substituent R n R m They can be arbitrarily connected to form a ring.

6. The organic electroluminescent device as described in claim 5, wherein the ring D, each time it appears, is selected from benzene ring, naphthalene ring, phenanthrene ring, fluorene ring, triphenylene ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, pyridine ring, and combinations thereof; The L1 is selected from single bonds, substituted or unsubstituted phenylene, or substituted or unsubstituted naphthylene; R n R m 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 aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted amino, cyano, hydroxyl, mercapto groups having 0-20 carbon atoms, and combinations thereof.

7. The organic electroluminescent device of claim 6, wherein L1 is selected from single bonds.

8. The organic electroluminescent device of claim 1, wherein L is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； in, In the structures L-1 to L-20, "*" indicates the position where the structure is connected to the N atom in Formula 1. " indicates the position where the structure is connected to the E structure; Optionally, the hydrogen in the structures of L-1 to L-20 may be partially or completely replaced by deuterium.

9. The organic electroluminescent device of claim 1, wherein the host material is selected from the group consisting of compounds 1 to 41: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； in, Optionally, the hydrogen in compounds 1 to 41 can be partially or completely replaced by deuterium.

10. The organic electroluminescent device as claimed in claim 1, wherein, The energy level difference between the HOMO level of the first organic material and the HOMO level of the host material is less than 0.2 eV.

11. The organic electroluminescent device as claimed in claim 10, wherein, The energy level difference between the HOMO level of the first organic material and the HOMO level of the host material is less than 0.15 eV.

12. The organic electroluminescent device as claimed in claim 1, wherein, The HOMO energy level of the first organic material is less than -5.25 eV.

13. The organic electroluminescent device as claimed in claim 1, wherein the first organic material has the structure represented by Formula 4: in, In Equation 4, Each time Y1 to Y8 appears, it is selected from CR1 or N in the same or different ways; L2, each time it appears, is selected from the same or different substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof; Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, either in the same or different manner. R1, each time appearing, is selected from the group consisting of, either identically or differently from, hydrogen, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryl group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms; Adjacent substituents R1 can optionally connect to form a ring.

14. The organic electroluminescent device as claimed in claim 13, wherein, The L2 is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted fluorene, substituted or unsubstituted silylfluorene, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dibenzoselenophenyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted terphenylene, substituted or unsubstituted pyridyl, substituted or unsubstituted spirodifluorene, substituted or unsubstituted anthracene, substituted or unsubstituted pyrene, or combinations thereof.

15. The organic electroluminescent device as claimed in claim 14, wherein, The L2 is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted fluorene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted dibenzothiopheneylene, substituted or unsubstituted phenanthylene, substituted or unsubstituted anthraceneylene, and substituted or unsubstituted pyreneylene.

16. The organic electroluminescent device as claimed in claim 15, wherein, The L2 is phenylene, biphenylene, terphenylene, naphthylene, phenanthrene, dibenzofuranylene, dimethylfluorene, diphenylfluorene, or spirofluorene.

17. The organic electroluminescent device as claimed in claim 13, wherein, Ar1 and Ar2, each time they appear, are selected from substituted or unsubstituted aryl groups having 6-20 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms.

18. The organic electroluminescent device of claim 17, wherein, The Ar1 and Ar2, each time appearing, are selected from phenyl, 4-tert-butylphenyl, 4-diphenylaminophenyl, phenylnaphthyl, biphenyl, terphenyl, naphthyl, phenanthryl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9,9-spirodifluorenyl, pyridyl, or pyrimidinyl.

19. The organic electroluminescent device of claim 1, wherein the first organic material is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， 。 20. The organic electroluminescent device as claimed in claim 1, wherein, The thickness of the first organic layer is less than 20 nm.

21. The organic electroluminescent device as claimed in claim 20, wherein, The thickness of the first organic layer is less than 10 nm.

22. The organic electroluminescent device as claimed in claim 1, wherein, The first electrode has an average reflectivity greater than 50% in the visible light region.

23. The organic electroluminescent device as described in claim 22, wherein, The first electrode has an average reflectivity greater than 70% in the visible light region.

24. The organic electroluminescent device as claimed in claim 23, wherein, The first electrode has an average reflectivity greater than 80% in the visible light region.

25. The organic electroluminescent device as claimed in claim 1, wherein, The average transmittance of the second electrode in the visible light region is greater than 15%.

26. The organic electroluminescent device as claimed in claim 25, wherein, The average transmittance of the second electrode in the visible light region is greater than 20%.

27. The organic electroluminescent device as claimed in claim 26, wherein, The average transmittance of the second electrode in the visible light region is greater than 25%.

28. The organic electroluminescent device as claimed in claim 1, wherein, The first electrode is formed of a material selected from the group consisting of Ag, Al, Ti, Cr, Pt, Ni, TiN, and combinations of the above materials with ITO and / or MoOx (molybdenum oxide); The second electrode is formed of a material selected from the group consisting of MgAg alloy, MoOx, Yb, Ca, ITO, IZO, and combinations thereof.

29. The organic electroluminescent device as claimed in claim 1, wherein, It further includes a third organic layer and a fourth organic layer, wherein the third organic layer contains a third organic material and the fourth organic layer contains a fourth organic material.

30. The organic electroluminescent device as claimed in claim 29, wherein, The HOMO energy levels of the third and fourth organic materials are both greater than the HOMO energy level of the first organic material.

31. The organic electroluminescent device as described in claim 29, wherein, The third organic layer and the fourth organic layer are disposed between the first electrode and the first organic layer, and the third organic layer and the fourth organic layer are in direct contact, and the fourth organic layer is in direct contact with the first organic layer.

32. A display component comprising an organic electroluminescent device as claimed in any one of claims 1-31.

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