Organic light-emitting device, display device and organic light-emitting ink

Abstract

Disclosed are an organic electroluminescent device, a display device, and an organic light-emitting ink. The organic light-emitting device comprises an anode, a cathode, a light-emitting layer arranged between the anode and the cathode, and a first organic layer arranged between the anode and the light-emitting layer, the first organic layer comprises a polymer, and the light-emitting layer is prepared by a solution method and comprises a first host compound and a second host compound, the invention relates to a platinum metal complex and a thermally activated delayed fluorescent compound represented by a formula 1 structure. The organic electroluminescent device has the advantages of low cost, simple process and the like, and meanwhile, compared with a common TADF device without a platinum metal complex as a phosphorescence sensitizer, the organic electroluminescent device can keep narrower half-peak width, greatly improves the device efficiency, shows very excellent device performance and has a wide application prospect. The invention also discloses a display device comprising the organic light-emitting device, and organic light-emitting ink.

Description

Technical Field

[0001] The present invention relates to organic electronic devices, such as organic light-emitting devices. More particularly, it relates to an organic light-emitting device having a light-emitting layer prepared by a solution process, a display device including the organic light-emitting device, and an organic light-emitting ink. Background Art

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

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a bilayer organic light-emitting device that included an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as 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 from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). The most advanced 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 a cathode and an anode. Since OLEDs are a self-emitting solid-state device, they offer great potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, can make them very suitable for special applications, such as the fabrication on flexible substrates.

[0004] OLEDs can be classified into three different types according to their emission mechanisms. The OLED invented by Tang and van Slyke is a fluorescent OLED. It only uses singlet emission. The triplets generated in the device are wasted through non-radiative decay channels. Therefore, the internal quantum efficiency (IQE) of fluorescent OLEDs is only 25%. This limitation has hindered the commercialization of OLEDs. In 1997, Forrest and Thompson reported phosphorescent OLEDs, which use triplet emission from heavy metals in complexes as emitters. Therefore, it is able to harvest both singlet and triplet states, achieving 100% IQE. Due to its high efficiency, the discovery and development of phosphorescent OLEDs have 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-triplet energy gaps, making it possible for excitons to return from triplets to singlets. 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 and polymer OLEDs according to the form of the materials used. Small molecules refer to any organic or organometallic materials that are not polymers. As long as they have precise structures, the molecular weights of small molecules can be very large. Dendrimers with well-defined structures are considered small molecules. Polymer OLEDs include conjugated polymers and non-conjugated polymers with side-chain emitting groups. If post-polymerization occurs during the manufacturing process, small molecule OLEDs can turn into polymer OLEDs.

[0006] There are various methods for manufacturing OLEDs. Small molecule OLEDs are usually manufactured by vacuum thermal evaporation (evaporation method). Polymer OLEDs are manufactured by solution methods such as spin coating, inkjet printing, and nozzle printing. If the materials can be dissolved or dispersed in solvents, small molecule OLEDs can also be manufactured by solution methods.

[0007] The emission colors of OLEDs can be achieved through the structural design of the emitting materials. OLEDs can include one emitting layer or multiple emitting layers to achieve the desired spectrum. For green, yellow, and red OLEDs, phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still have problems such as blue color unsaturation, short device lifetime, and high operating voltage. Commercial full-color OLED displays usually adopt a hybrid strategy, using blue fluorescence and phosphorescent yellow, or red and green. Currently, the rapid reduction of the efficiency of phosphorescent OLEDs at high brightness is still a problem. In addition, more saturated emission spectra, higher efficiency, and longer device lifetimes are desired.

[0008] In the preparation of organic electroluminescent devices, when the organic functional layer contains multiple compounds in a multi-component system, multiple evaporation sources are required for vapor deposition (for example, if the light-emitting layer contains two host materials, a phosphorescent sensitizer, and a thermally activated delayed fluorescence material, four evaporation sources are needed), which greatly increases the industrial cost and the process is complex. At the same time, when preparing the organic functional layer by vapor deposition, the vapor deposition temperature of the compound to be vapor deposited cannot be too high, otherwise the energy consumption will increase significantly or the vapor deposition method cannot be used for preparation, which also limits the range of selectable compounds. While the solution method only requires dissolving or dispersing multiple compounds in a solvent to prepare a functional layer organic ink that can be spin-coated or printed, which has advantages such as low cost and simple process. Some prior arts disclose the use of the solution method to prepare organic functional layers in organic electroluminescent devices. For example, it can prepare a hole injection layer, a hole transport layer, and a light-emitting layer, etc. However, the materials disclosed in these prior arts all have certain specific structures in the organic functional layer.

[0009] CN116023402A discloses a boron nitride compound, and its general formula I is wherein R2 is selected from large steric hindrance linear groups with weak electron-donating or electron-withdrawing properties, and the specific R2 is and other substituents. It can be seen that what this application discloses is a boron nitride compound with a specific large steric hindrance linear group of R2, and does not disclose or teach other boron nitride compounds and their applications in organic electroluminescent devices. In addition, in the device examples, this application prepared the hole injection layer, hole transport layer, and light-emitting layer of the organic electroluminescent device by the solution method. Among them, a specific PEDOT / PSS combination was used for the hole injection layer, a specific Poly-HTL material was used for the hole transport layer, and the light-emitting layer contained a dual host material, a phosphorescent sensitizer, and the specific compound of formula I. However, this application does not disclose or teach a device in which a polymer is included in the hole injection layer or hole transport layer, and other boron nitride compounds are used as the light-emitting layer together with the dual host material and the phosphorescent sensitizer.

[0010] CN115440903A discloses an organic light-emitting material composition, which includes a host material, a phosphorescent material, and a thermally activated delayed fluorescence material, and specifically discloses that the phosphorescent material is Iridium metal complexes and the like. Further disclosed is an organic light-emitting ink comprising the organic light-emitting material composition, and an organic electroluminescent device fabricated through the organic light-emitting ink. In the device examples of this application, a hole injection layer, a hole transport layer, and a light-emitting layer of the organic electroluminescent device were prepared by a solution method. In the hole injection layer, a specific PEDOT / PSS combination was used; in the hole transport layer, a specific PVK material was used; and in the light-emitting layer, a dual host material, a thermally activated delayed fluorescence material, and an iridium metal complex were included as a phosphorescent sensitizer. However, this application does not disclose or teach a device in which a polymer is included in the hole injection layer or the hole transport layer, while using other phosphorescent sensitizers, a dual host material, and a thermally activated delayed fluorescence material in the light-emitting layer.

[0011] Currently, in sensitized delayed fluorescence devices prepared by a solution method, the combination of organic functional layers, such as the combination between the hole injection layer and / or the hole transport layer and the light-emitting layer, and the combination of organic materials used in the light-emitting layer need to be further researched and developed, and the performance of the device, such as device efficiency, still needs to be improved. Summary of the Invention

[0012] The present invention aims to provide a novel organic electroluminescent device to solve at least some of the above problems. This novel organic electroluminescent device includes an anode, a cathode, a light-emitting layer disposed between the anode and the cathode, and a first organic layer disposed between the anode and the light-emitting layer. The first organic layer contains a polymer. The light-emitting layer of the present invention is prepared by a solution method and includes a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound represented by the structure of Formula 1. Since the light-emitting layer of the organic electroluminescent device of the present invention is prepared by a solution method, the organic functional layer between the anode and the light-emitting layer, such as the first organic layer, needs to contain a polymer and cannot contain only small molecules, otherwise the interface / membrane layer of the organic functional layer between the anode and the light-emitting layer may be damaged during the process of fabricating the device by the solution method. The organic electroluminescent device of the present invention not only has the advantages of low cost and simple process brought by using the solution method, but also can maintain a relatively narrow full width at half maximum and significantly improve the device efficiency compared with ordinary TADF devices without a platinum metal complex as a phosphorescent sensitizer, showing very excellent device performance and having broad application prospects.

[0013] According to an embodiment of the present invention, an organic electroluminescent device is disclosed, which includes:

[0014] An anode,

[0015] A cathode,

[0016] A light-emitting layer disposed between the anode and the cathode, and a first organic layer disposed between the anode and the light-emitting layer;

[0017] Among them, the first organic layer contains a polymer;

[0018] The light-emitting layer is prepared by a solution method, and the light-emitting layer contains a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound;

[0019] Among them, the thermally activated delayed fluorescence compound has a structure represented by Formula 1:

[0020]

[0021] Among them,

[0022] Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from an unsaturated carbocyclic ring having 5 to 30 carbon atoms or an unsaturated heterocyclic ring having 3 to 30 carbon atoms;

[0023] Y1, E1, and E2 are each independently selected from B, N, P, P=O, P=S, As, As=O, As=S, SiR', or GeR';

[0024] T1 to T8 are each independently selected from C, CR z or N;

[0025] T9 and T 10 are each independently selected from C, CR z , CR t or N;

[0026] L1, L2, L3, L4 are the same or different each time they appear and are selected from a single bond, O, S, Se, BR v or NR v ;

[0027] a, b, c, d, e are each independently selected from 0 or 1;

[0028] When e is 1, b is 0, and c is 0, T9 and T 10 are each independently selected from CR t or N;

[0029] R z is the same or different each time it appears and represents monosubstituted, polysubstituted, or unsubstituted;

[0030] R t is the same or different each time it appears and is selected from small steric hindrance groups;

[0031] R v ,R zR and R’ are each independently selected, each time they appear, from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof;

[0032] R” is each independently selected, each time it appears, from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0033] Adjacent substituents R t ,R v ,R z ,R’, and R” may optionally be joined to form a ring.

[0034] According to another embodiment of the present invention, a display device is also disclosed, which includes the organic electroluminescent device as described above.

[0035] According to another embodiment of the present invention, an organic light-emitting ink is also disclosed, which includes a solvent, a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound;

[0036] Wherein the thermally activated delayed fluorescence compound has a structure represented by Formula 1:

[0037]

[0038] Wherein,

[0039] Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from an unsaturated carbocyclic ring having 5 - 30 carbon atoms or an unsaturated heterocyclic ring having 3 - 30 carbon atoms;

[0040] Y1, E1, and E2 are each independently selected from B, N, P, P=O, P=S, As, As=O, As=S, SiR', or GeR';

[0041] T1 to T8 are each independently selected from C, CR z or N;

[0042] T9 and T 10 are each independently selected from C, CR z , CR t or N;

[0043] L1, L2, L3, L4 are the same or different each time they appear and are selected from a single bond, O, S, Se, BR v or NR v ;

[0044] a, b, c, d, e are each independently selected from 0 or 1;

[0045] When e is 1, b is 0, and c is 0, T9 and T 10 are each independently selected from CR t or N;

[0046] R z is the same or different each time it appears and represents mono-substituted, multi-substituted, or unsubstituted;

[0047] R t is the same or different each time it appears and is selected from small steric hindrance groups;

[0048] R v ,R zR and R’ are each independently selected, each time they appear, from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof;

[0049] R” is each independently selected, each time it appears, from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0050] Adjacent substituents R t ,R v ,R z ,R’, and R” may optionally be joined to form a ring.

[0051] The present invention aims to provide a novel organic light-emitting device. This novel organic light-emitting device includes an anode, a cathode, a light-emitting layer disposed between the anode and the cathode, and a first organic layer disposed between the anode and the light-emitting layer. The first organic layer contains a polymer. The light-emitting layer is prepared by a solution method and contains a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound represented by the structure of Formula 1. Since the light-emitting layer of the organic light-emitting device of the present invention is prepared by a solution method, the organic functional layer between the anode and the light-emitting layer, such as the first organic layer, needs to contain a polymer and cannot contain only small molecules, otherwise the interface / membrane layer of the organic functional layer between the anode and the light-emitting layer may be damaged during the device preparation process using the solution method. The organic light-emitting device of the present invention not only has the advantages of low cost and simple process brought by using the solution method, but also can maintain a relatively narrow full width at half maximum and significantly improve the device efficiency compared with ordinary TADF devices without a platinum metal complex as a phosphorescent sensitizer, showing very excellent device performance and having broad application prospects. Description of the Drawings

[0052] Figure 1 It is a schematic diagram of an organic light-emitting device that can contain the organic light-emitting device disclosed herein.

[0053] Figure 2 It is another schematic diagram of an organic light-emitting device that can contain the organic light-emitting device disclosed herein. Detailed Description

[0054] OLEDs can be fabricated on various substrates such as glass, plastic, and metal. Figure 1 Schematically and non-limitingly shows an organic light-emitting device 100. The figures are not necessarily drawn to scale, and some layer structures in the figures can also be omitted as needed. The device 100 may include a substrate 101, an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode 190. The device 100 can be fabricated by sequentially depositing the described layers. The properties and functions of each layer and exemplary materials are described in more detail in columns 6-10 of US Patent US7,279,704B2, and the entire content of the above patent is incorporated herein by reference.

[0055] Each of these layers has more examples. For example, 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. Examples of host materials are disclosed in U.S. Patent No. 6,303,238, issued 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. U.S. Patents Nos. 5,703,436 and 5,707,745, incorporated herein by reference in their entireties, disclose examples of cathodes including a composite cathode having a thin layer of a metal such as Mg:Ag and an overlying transparent, conductive, sputter-deposited ITO layer. The principles and use of the barrier layer are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, incorporated herein by reference in their entireties. Examples of the injection layer are provided in U.S. Patent Application Publication No. 2004 / 0174116, incorporated herein by reference in its entirety. A description of the protective layer can be found in U.S. Patent Application Publication No. 2004 / 0174116, incorporated herein by reference in its entirety.

[0056] The above-described layered structure is provided by way of non-limiting examples. The function of the OLED can be achieved by combining the various layers described above, or some layers can be completely omitted. It can 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 can include several sub-layers. For example, the light-emitting layer can have two different light-emitting materials to achieve a desired emission spectrum.

[0057] In one embodiment, the OLED can be described as having an "organic layer" disposed between the cathode and the anode. The organic layer can include one or more layers.

[0058] The OLED also requires a encapsulation layer, as Figure 2 Schematically and non-limitingly shows an organic light-emitting device 200, which is associated with Figure 1In contrast, a encapsulation layer 102 may also be included over the cathode 190 to prevent harmful substances from the environment, such as moisture and oxygen. Any material capable of providing an encapsulation function 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 US7,968,146B2, the entire content of which is incorporated herein by reference.

[0059] 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) with the device. 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, smart phones, tablet computers, phablets, wearable devices, smart watches, laptop computers, digital cameras, portable video cameras, viewfinders, microdisplays, 3-D displays, vehicle displays, and taillights.

[0060] The materials and structures described herein can also be used in other organic electronic devices listed above.

[0061] As used herein, "top" means furthest from the substrate, and "bottom" means closest to the substrate. In the case where a first layer is described as "disposed" "on" a second layer, the first layer is disposed 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 though there are various organic layers between the cathode and the anode, the cathode can still be described as "disposed on" the anode.

[0062] As used herein, "solution processable" means capable of being dissolved, dispersed, or transported in a liquid medium in the form of a solution or suspension and / or deposited from a liquid medium.

[0063] When it is believed that a ligand directly contributes to the photosensitive properties of an emissive material, the ligand can be referred to as "photosensitive". When it is believed that a ligand does not contribute to the photosensitive properties of an emissive material, the ligand can be referred to as "auxiliary", but an auxiliary ligand can modify the properties of a photosensitive ligand.

[0064] It is believed that the internal quantum efficiency (IQE) of a fluorescent OLED can exceed the 25% spin statistics limit by delayed fluorescence. Delayed fluorescence can generally be divided into two types, namely P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0065] On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the conversion between the triplet state and the singlet excited state. Compounds capable of generating E-type delayed fluorescence need to have an extremely small singlet-triplet gap for the energy state conversion. Thermal energy can activate the transition from the triplet state back to the singlet state. This type of delayed fluorescence is also known as thermally activated delayed fluorescence (TADF). A remarkable feature of TADF is that the delayed component increases with increasing temperature. If the rate of reverse intersystem crossing (RISC) is fast enough to minimize the non-radiative decay from the triplet state, the fraction of the singlet excited state refilled can reach 75%. The total singlet fraction can be 100%, far exceeding the 25% of the spin statistics of electro-generated excitons.

[0066] The characteristics of E-type delayed fluorescence can be found in exciplex systems or single compounds. Without being bound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet energy gap (ΔE S-T ). Organic non-metal-containing donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is usually characterized as donor-acceptor charge transfer (CT) type emission. The spatial separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in these donor-acceptor type compounds usually results in a small ΔE S-T . These states can include CT states. Generally, donor-acceptor luminescent materials are constructed by connecting an electron donor moiety (such as an amino or carbazole derivative) to an electron acceptor moiety (such as an N-containing six-membered aromatic ring).

[0067] Definition of substituent terms

[0068] Halogen or halide - as used herein, includes fluorine, chlorine, bromine, and iodine.

[0069] Alkyl - as used herein, includes straight-chain and branched-chain alkyls. The alkyl can be an alkyl having 1 to 20 carbon atoms, preferably an alkyl having 1 to 12 carbon atoms, more preferably an alkyl having 1 to 6 carbon atoms. Examples of alkyls include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, 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 can be optionally substituted.

[0070] Cycloalkyl - As used herein, cycloalkyl includes cyclic alkyl groups. The cycloalkyl can be a cycloalkyl having 3 to 20 ring carbon atoms, preferably a cycloalkyl having 4 to 10 carbon atoms. Examples of cycloalkyl 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. Additionally, the cycloalkyl can be optionally substituted.

[0071] Heteroalkyl - As used herein, heteroalkyl is formed by replacing one or more carbons in an alkyl chain with a heteroatom selected from the group consisting of nitrogen atom, oxygen atom, sulfur atom, selenium atom, phosphorus atom, silicon atom, germanium atom, and boron atom. The heteroalkyl can be a heteroalkyl having 1 to 20 carbon atoms, preferably a heteroalkyl having 1 to 10 carbon atoms, more preferably a heteroalkyl having 1 to 6 carbon atoms. Examples of heteroalkyl include methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermylmethyl, trimethylgermylethyl, trimethylgermylisopropyl, dimethylethylgermylmethyl, dimethylisopropylgermylmethyl, tert - butyldimethylgermylmethyl, triethylgermylmethyl, triethylgermylethyl, triisopropylgermylmethyl, triisopropylgermylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl, triisopropylsilylethyl. Additionally, the heteroalkyl can be optionally substituted.

[0072] Alkenyl - As used herein, it encompasses straight - chain, branched - chain, and cyclic olefin groups. The alkenyl can be an alkenyl having 2 to 20 carbon atoms, preferably an alkenyl having 2 to 10 carbon atoms. Examples of alkenyl include vinyl, propenyl, 1 - butenyl, 2 - butenyl, 3 - butenyl, 1,3 - butadienyl, 1 - methylvinyl, styryl, 2,2 - diphenylethylene, 1,2 - diphenylethylene, 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, cycloheptatriene, cyclooctenyl, cyclooctatetraene, and norbornenyl. Additionally, the alkenyl can be optionally substituted.

[0073] Alkynyl - As used herein, it encompasses straight-chain alkynyl. The alkynyl can be an alkynyl having 2 to 20 carbon atoms, preferably an alkynyl having 2 to 10 carbon atoms. Examples of alkynyl include ethynyl, propynyl, propargyl, 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, phenylacetylenyl, phenylpropynyl, etc. Among the above, ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, and phenylacetylenyl are preferred. Additionally, the alkynyl can be optionally substituted.

[0074] Aryl or aromatic group - As used herein, non-fused and fused systems are considered. The aryl can be an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 20 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms. Examples of aryl include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, fluoranthene, phenanthrene, fluorene, pyrene, perylene, and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene, and naphthalene. Examples of non-fused aryl include phenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, 4-p-terphenyl, 3-p-terphenyl, 2-p-terphenyl, 4-m-terphenyl, 3-m-terphenyl, 2-m-terphenyl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenylyl, 4''-tert-butyl-4-p-terphenyl, o-cumyl, m-cumyl, p-cumyl, 2,3-dimethylphenyl, 3,4-dimethylphenyl, 2,5-dimethylphenyl, mesityl, and m-quaterphenyl. Additionally, the aryl can be optionally substituted.

[0075] Heterocyclic group - As used herein, non-aromatic cyclic groups are considered. The non-aromatic heterocyclic group includes 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 atom, oxygen atom, sulfur atom, selenium atom, silicon atom, phosphorus atom, germanium atom, and boron atom. Preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms, which include at least one heteroatom such as nitrogen, oxygen, silicon, or sulfur. Examples of non-aromatic heterocyclic groups include oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, aziridinyl, dihydropyrrolyl, tetrahydropyrrolyl, piperidinyl, oxazolidinyl, morpholinyl, piperazinyl, oxepinyl, thiepinyl, azepinyl, and tetrahydrothienyl. Additionally, the heterocyclic group can be optionally substituted.

[0076] Heteroaryl - As used herein, it can include non - fused and fused heteroaromatic groups having 1 to 5 heteroatoms, wherein at least one heteroatom is selected from the group consisting of nitrogen atom, oxygen atom, sulfur atom, selenium atom, silicon atom, phosphorus atom, germanium atom and boron atom. Isoaryl also refers to heteroaryl. The heteroaryl can be a heteroaryl having 3 to 30 carbon atoms, preferably a heteroaryl having 3 to 20 carbon atoms, more preferably a heteroaryl having 3 to 12 carbon atoms. Suitable heteroaryls include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridoindole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indenoazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, benzofuranopyridine, furanodipyridine, benzothiophenopyridine, thiophenodipyridine, benzoselenophenopyridine, selenophenodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2 - azaborolane, 1,3 - azaborolane, 1,4 - azaborolane, borazole and their nitrogen - containing analogues. Additionally, the heteroaryl can be optionally substituted.

[0077] Alkoxy - As used herein, it is represented by -O - alkyl, -O - cycloalkyl, -O - heteroalkyl or -O - heterocyclic group. Examples and preferred examples of alkyl, cycloalkyl, heteroalkyl and heterocyclic group are the same as those described above. The alkoxy can be an alkoxy having 1 to 20 carbon atoms, preferably an alkoxy having 1 to 6 carbon atoms. Examples of alkoxy include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, tetrahydrofuryloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy and ethoxymethyloxy. Additionally, the alkoxy can be optionally substituted.

[0078] Aryloxy - As used herein, it is represented by -O - aryl or -O - heteroaryl. Examples and preferred examples of aryl and heteroaryl are the same as those described above. The aryloxy can be an aryloxy having 6 to 30 carbon atoms, preferably an aryloxy having 6 - 20 carbon atoms. Examples of aryloxy include phenoxy and biphenyloxy. Additionally, the aryloxy can be optionally substituted.

[0079] Aralkyl - as used herein, encompasses aryl-substituted alkyl groups. The aralkyl group may be an aralkyl group having 7 to 30 carbon atoms, preferably an aralkyl group having 7 to 20 carbon atoms, and more preferably an aralkyl group having 7 to 13 carbon atoms. Examples of aralkyl 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, substituted alkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl,

[0080] Alkylsilyl - As used herein, encompasses alkyl-substituted silicon groups. The alkylsilyl group may 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, tri-tert-butylsilyl, triisobutylsilyl, dimethyl-tert-butylsilyl, and methyldi-tert-butylsilyl. Additionally, the alkylsilyl group may be optionally substituted.

[0081] Arylsilyl - As used herein, encompasses silicon groups substituted with at least one aryl group. The arylsilyl group may be one having 6 to 30 carbon atoms, preferably one having 8 to 20 carbon atoms. Examples of arylsilyl groups include triphenylsilyl, phenyldibiphenylsilyl, diphenylbiphenylsilyl, phenyldiethylsilyl, diphenylethylsilyl, phenyldimethylsilyl, diphenylmethylsilyl, phenyldiisopropylsilyl, diphenylisopropylsilyl, diphenylbutylsilyl, diphenylisobutylsilyl, and diphenyltert-butylsilyl. Additionally, the arylsilyl group may be optionally substituted.

[0082] Alkylgermyl – As used herein, encompasses alkyl-substituted germyl groups. The alkylgermyl group can be an alkylgermyl group having 3 to 20 carbon atoms, preferably an alkylgermyl group having 3 to 10 carbon atoms. Examples of alkylgermyl groups include trimethylgermyl, triethylgermyl, methyldiethylgermyl, ethyldimethylgermyl, tripropylgermyl, tributylgermyl, triisopropylgermyl, methyldiisopropylgermyl, dimethylisopropylgermyl, tritert-butylgermyl, triisobutylgermyl, dimethyltert-butylgermyl, methylditert-butylgermyl. Additionally, the alkylgermyl group can be optionally substituted.

[0083] Arylgermyl – As used herein, encompasses germyl groups substituted with at least one aryl or heteroaryl group. The arylgermyl group can be an arylgermyl group having 6 to 30 carbon atoms, preferably an arylgermyl group having 8 to 20 carbon atoms. Examples of arylgermyl groups include triphenylgermyl, phenyldibiphenylgermyl, diphenylbiphenylgermyl, phenyldiethylgermyl, diphenylethylgermyl, phenyldimethylgermyl, diphenylmethylgermyl, phenyldiisopropylgermyl, diphenylisopropylgermyl, diphenylbutylgermyl, diphenylisobutylgermyl, diphenyltert-butylgermyl. Additionally, the arylgermyl group can be optionally substituted.

[0084] The term "aza" in azadibenzofuran, azadibenzothiophene, etc. means that one or more C-H groups in the corresponding aromatic moiety are replaced by nitrogen atoms. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline, and other analogs having two or more nitrogens in the ring system. Other nitrogen analogs of the above-described aza derivatives can be readily envisioned by those of ordinary skill in the art, and all such analogs are determined to be included within the terms described herein.

[0085] In the present disclosure, unless otherwise defined, when any one of the terms consisting of the following groups is used: substituted alkyl, substituted cycloalkyl, substituted heteroalkyl, substituted heterocycloalkyl, substituted aralkyl, substituted alkoxy, substituted aryloxy, substituted alkenyl, substituted alkynyl, substituted aryl, substituted heteroaryl, substituted alkylsilyl, substituted arylsilyl, substituted alkylgermyl, substituted arylgermyl, substituted amino, substituted acyl, substituted carbonyl, substituted carboxy, substituted ester, substituted sulfinyl, substituted sulfonyl, substituted phosphino, it means that any one of the groups of alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermyl, arylgermyl, amino, acyl, carbonyl, carboxy, ester, sulfinyl, sulfonyl and phosphino may be substituted by one or more substituents selected from deuterium, halogen, unsubstituted alkyl having 1-20 carbon atoms, unsubstituted cycloalkyl having 3-20 ring carbon atoms, unsubstituted heteroalkyl having 1-20 carbon atoms, unsubstituted heterocycloalkyl having 3-20 ring atoms, unsubstituted aralkyl having 7-30 carbon atoms, unsubstituted alkoxy having 1-20 carbon atoms, unsubstituted aryloxy having 6-30 carbon atoms, unsubstituted alkenyl having 2-20 carbon atoms, unsubstituted alkynyl having 2-20 carbon atoms, unsubstituted aryl having 6-30 carbon atoms, unsubstituted heteroaryl having 3-30 carbon atoms, unsubstituted alkylsilyl having 3-20 carbon atoms, unsubstituted arylsilyl having 6-20 carbon atoms, unsubstituted alkylgermyl having 3-20 carbon atoms, unsubstituted arylgermyl having 6-20 carbon atoms, unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxy, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl, phosphino and combinations thereof.

[0086] It should be understood that when a molecular fragment is described as a substituent or otherwise attached to another moiety, its name may be written according to whether it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is the entire molecule (such as benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or linking fragments are considered equivalent.

[0087] In the compounds mentioned in the present disclosure, the hydrogen atoms may be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen may also be replaced by their other stable isotopes. Replacement of other stable isotopes in the compounds may be preferred due to their enhanced device efficiency and stability.

[0088] Among the compounds mentioned in the present disclosure, polysubstituted refers to the range including disubstituted up to the maximum available substitution. When a substituent in the compounds mentioned in the present disclosure indicates polysubstituted (including disubstituted, trisubstituted, tetrasubstituted, etc.), it means that the substituent can be present at multiple available substitution positions on its connecting structure, and the substituent present at multiple available substitution positions can be of the same structure or different structures.

[0089] Among the compounds mentioned in the present disclosure, unless explicitly defined, for example, adjacent substituents can optionally be connected to form a ring, otherwise adjacent substituents in the compound cannot be connected to form a ring. Among the compounds mentioned in the present disclosure, adjacent substituents can optionally be connected to form a ring, which includes both the case where adjacent substituents can be connected to form a ring and the case where adjacent substituents are not connected to form a ring. When adjacent substituents can optionally be connected to form a ring, the formed ring can be a monocyclic or polycyclic ring (including spiro ring, bridged ring, fused ring, etc.), and an alicyclic ring, heteroalicyclic ring, aromatic ring or heteroaromatic ring. In this expression, 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.

[0090] The expression that adjacent substituents can optionally be connected to form a ring is also intended to be considered as referring to two substituents bonded to the same carbon atom being connected to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0091]

[0092] The expression that adjacent substituents can optionally be connected to form a ring is also intended to be considered as referring to two substituents bonded to carbon atoms directly bonded to each other being connected to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0093]

[0094] The expression that adjacent substituents can optionally be connected to form a ring is also intended to be considered as referring to two substituents bonded to carbon atoms further away being connected to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0095]

[0096] In addition, the expression that adjacent substituents can optionally be connected to form a ring is also intended to be considered as referring to, in the case where one of the two adjacent substituents represents hydrogen, the second substituent being bonded to the position where the hydrogen atom is bonded, thereby forming a ring. This is exemplified by the following formula:

[0097]

[0098] According to an embodiment of the present invention, an organic electroluminescent device is disclosed, which comprises:

[0099] An anode,

[0100] A cathode,

[0101] A light-emitting layer disposed between the anode and the cathode, and a first organic layer disposed between the anode and the light-emitting layer;

[0102] Wherein, the first organic layer comprises a polymer;

[0103] The light-emitting layer is prepared by a solution method, and the light-emitting layer comprises a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound;

[0104] Wherein the thermally activated delayed fluorescence compound has a structure represented by Formula 1:

[0105]

[0106] Wherein,

[0107] Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from an unsaturated carbocyclic ring having 5 - 30 carbon atoms or an unsaturated heterocyclic ring having 3 - 30 carbon atoms;

[0108] Y1, E1, and E2 are each independently selected from B, N, P, P=O, P=S, As, As=O, As=S, SiR', or GeR';

[0109] T1 to T8 are each independently selected from C, CR z Or N;

[0110] T9 and T 10 Are each independently selected from C, CR z , CR t Or N;

[0111] L1, L2, L3, and L4 are the same or different each time they appear and are selected from a single bond, O, S, Se, BR v Or NR v ;

[0112] a, b, c, d, and e are each independently selected from 0 or 1;

[0113] When e is 1, b is 0, and c is 0, T9 and T 10 Are each independently selected from CR t Or N;

[0114] R zindependently represents, each occurrence, mono-substitution, multi-substitution or no substitution, either identically or differently;

[0115] R t is independently selected, each occurrence, from small steric hindrance groups;

[0116] R v , R z and R', each occurrence, are independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof;

[0117] R” is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0118] Adjacent substituents R t ,R v ,R z ,R', and R” can optionally be joined to form a ring.

[0119] In this embodiment, “a, b, c, d, e are each independently selected from 0 or 1” is intended to mean the presence or absence of L1, L2, L3, L4, Y1 corresponding to a, b, c, d, e. For example: when a is 1, at this time L1 is present, and T1 and T2 are connected by L1; when a is 0, at this time L1 is absent, and T1 and T2 are not connected; when b, c, d are each independently selected from 0 or 1, the situation is similar to that of a. When e is 1, at this time Y1 is present, and ring A is connected to T8 on ring B and T7 on ring C through Y1; when e is 0, at this time Y1 is absent, and rings A, B, and C are not connected.

[0120] In this article, “adjacent substituents R t ,R v ,R z ,R', and R” can optionally be joined to form a ring” is intended to mean the adjacent substituent groups among them. For example, between two substituents R z , between two substituents R”, between substituent R z and R v , between substituent R z and R', and between substituent R z and R tAmong them, any one or more of these adjacent substituent groups can be connected to form a ring. Obviously, none of these adjacent substituent groups may be connected to form a ring either.

[0121] As used herein, "unsaturated carbocyclic ring" includes aromatic unsaturated carbocyclic rings (aryl rings) and non-aromatic unsaturated carbocyclic rings, and "unsaturated heterocyclic ring" includes aromatic unsaturated heterocyclic rings (heteroaryl rings) and non-aromatic unsaturated heterocyclic rings.

[0122] As used herein, "small steric hindrance group" is intended to mean a substituent having 6 or fewer carbon atoms, and the "small steric hindrance group" is selected from the group consisting of: hydrogen, deuterium, halogen, unsubstituted alkyl having 1-6 carbon atoms, unsubstituted cycloalkyl having 3-6 ring carbon atoms, unsubstituted heteroalkyl having 1-6 carbon atoms, unsubstituted heterocyclic group having 3-6 ring atoms, unsubstituted alkoxy having 1-6 carbon atoms, unsubstituted alkenyl having 2-6 carbon atoms,

[0123] phenyl, pyridyl, pyrimidinyl, triazinyl, unsubstituted alkylsilyl having 3-6 carbon atoms, unsubstituted alkylgermyl having 3-6 carbon atoms, unsubstituted amino having 0-6 carbon atoms, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphino group.

[0124] According to one embodiment of the present invention, wherein the ring A, ring B, ring C, ring D and ring E are each independently selected from a five-membered unsaturated carbocyclic ring, an aryl ring having 6-30 carbon atoms or a heteroaryl ring having 3-30 carbon atoms.

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

[0126] According to one embodiment of the present invention, wherein the ring A, ring B, ring C, ring D and ring E are selected from benzene rings.

[0127] According to one embodiment of the present invention, in Formula 1, e is 1, each of Y1 is independently selected from B, P=O or P=S, and each of E1 and E2 is independently selected from N or P.

[0128] According to one embodiment of the present invention, in Formula 1, e is 1, Y1 is selected from B, and E1 and E2 are selected from N.

[0129] According to an embodiment of the present invention, in Formula 1, e is 1, a is 0, b is 0, c is 0, and d is 0.

[0130] According to an embodiment of the present invention, in Formula 1, e is 1, a is 1, b is 0, c is 0, and d is 1.

[0131] According to an embodiment of the present invention, in Formula 1, e is 1, a is 0, b is 1, c is 0, and d is 1.

[0132] According to an embodiment of the present invention, in Formula 1, e is 0, and E1 and E2 are each independently selected from B or N.

[0133] According to an embodiment of the present invention, in Formula 1, e is 0, and E1 and E2 are selected from B.

[0134] According to an embodiment of the present invention, in Formula 1, e is 0, a is 1, b is 1, c is 1, and d is 1.

[0135] According to an embodiment of the present invention, the thermally activated delayed fluorescence compound has a structure represented by Formula 1-1 or Formula 1-2:

[0136]

[0137] Wherein,

[0138] a, b, c, d are each independently selected from 0 or 1;

[0139] T9 and T 10 are each independently selected from C, CR z or CR t ;

[0140] When b is 0 and c is 0, T9 and T 10 are each independently selected from CR t ;

[0141] E1 and E2 are each independently selected from B or N;

[0142] L1, L2, L3, L4 are the same or different each time they appear and are selected from a single bond, O, S, BR v or NR v ;

[0143] R z is the same or different each time it appears and represents mono-substituted, multi-substituted or unsubstituted;

[0144] R t is the same or different each time it appears and is selected from small steric hindrance groups;

[0145] R v and Rz Each occurrence is the same as or different from each other and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof;

[0146] Each occurrence of R” is the same as or different from each other and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0147] Adjacent substituents R t ,R v ,R z and R” can optionally be linked to form a ring.

[0148] In this embodiment, "adjacent substituents R t , R v , R z and R" can optionally be joined to form a ring", which is intended to mean that two adjacent substituents R z on the same ring can be joined to form an unsaturated carbocyclic ring or an unsaturated heterocyclic ring containing one or more of O, S, Se, Si, Ge, P, two substituents R" can be joined to form a ring, substituents R z and R v can be joined to form a ring, and substituents R z and R t can be joined to form a ring. Obviously, two adjacent substituents R z on the same ring may not be joined to form a ring, two substituents R" may not be joined to form a ring, substituents R z and R v may not be joined to form a ring, and substituents R z and R t may not be joined to form a ring.

[0149] According to one embodiment of the present invention, in Formula 1-1, a is 0, b is 0, c is 0, and d is 0.

[0150] According to one embodiment of the present invention, in Formula 1-1, a + b + c + d is greater than or equal to 1.

[0151] According to one embodiment of the present invention, in Formula 1-1, a is 1, b is 0, c is 0, and d is 1.

[0152] According to one embodiment of the present invention, in Formula 1-1, a is 0, b is 1, c is 0, and d is 1.

[0153] According to one embodiment of the present invention, in Formula 1, Formula 1-1 and Formula 1-2, wherein each occurrence of L1, L2, L3, L4 is the same or different and is selected from a single bond, O, BR v or NR v , and each occurrence of the R v is the same or different and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms.

[0154] According to one embodiment of the present invention, in Formula 1-1, each occurrence of L1, L2, L3, and L4 is independently selected from a single bond, either the same or different each time.

[0155] According to one embodiment of the present invention, in Formula 1-2, each occurrence of L1, L2, L3, and L4 is independently selected from O or NR v , where said R v is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, each occurrence being either the same or different.

[0156] According to one embodiment of the present invention, in Formula 1-2, E1 and E2 are each independently selected from B.

[0157] According to one embodiment of the present invention, where said R z is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, and combinations thereof, each occurrence being either the same or different.

[0158] According to one embodiment of the present invention, where said R z is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, and combinations thereof, each occurrence being either the same or different.

[0159] According to one embodiment of the present invention, where there are multiple Rs in the thermally activated delayed fluorescence compound z , and said multiple Rs zAt least one of them (for example, one, two, three, or four) is selected from the group consisting of: a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3-20 ring carbon atoms, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, a substituted or unsubstituted amino group having 0-20 carbon atoms, and combinations thereof.

[0160] According to one embodiment of the present invention, wherein the substituent R on the ring A z is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3-20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1-20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3-20 ring atoms, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5-30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, a substituted or unsubstituted amino group having 0-20 carbon atoms, cyano, and combinations thereof.

[0161] According to one embodiment of the present invention, wherein the substituent R on the ring A z is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3-20 ring carbon atoms, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5-30 carbon atoms, a substituted or unsubstituted amino group having 0-20 carbon atoms, and combinations thereof.

[0162] According to one embodiment of the present invention, wherein the R t is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, an unsubstituted alkyl group having 1-6 carbon atoms, an unsubstituted cycloalkyl group having 3-6 ring carbon atoms, an unsubstituted heteroalkyl group having 1-6 carbon atoms, an unsubstituted heterocyclic group having 3-6 ring atoms, an unsubstituted alkylsilyl group having 3-6 carbon atoms, an unsubstituted amino group having 0-6 carbon atoms, phenyl, and combinations thereof.

[0163] According to one embodiment of the present invention, wherein the R t is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, an unsubstituted alkyl group having 1-6 carbon atoms, an unsubstituted cycloalkyl group having 3-6 ring carbon atoms, an unsubstituted amino group having 0-6 carbon atoms, and combinations thereof.

[0164] According to one embodiment of the present invention, wherein said R t is the same or different each time it appears and is selected from hydrogen, deuterium or a halogen.

[0165] According to one embodiment of the present invention, wherein the thermally activated delayed fluorescence compound is selected from the group consisting of Compound BD1 to Compound BD53, and the specific structures of Compound BD1 to Compound BD53 are shown in Claim 9.

[0166] According to one embodiment of the present invention, wherein the hydrogen in Compound BD1 to Compound BD53 can be partially or completely replaced by deuterium.

[0167] According to one embodiment of the present invention, wherein the maximum emission wavelength λ in the photoluminescence spectrum of the thermally activated delayed fluorescence compound max-PL is 450 nm to 500 nm.

[0168] According to one embodiment of the present invention, wherein the maximum emission wavelength λ in the photoluminescence spectrum of the thermally activated delayed fluorescence compound max-PL is 450 nm to 470 nm.

[0169] According to one embodiment of the present invention, wherein the maximum emission wavelength λ in the photoluminescence spectrum of the thermally activated delayed fluorescence compound max-PL is 455 nm to 470 nm.

[0170] According to one embodiment of the present invention, wherein the full width at half maximum FWHM- in the photoluminescence spectrum of the thermally activated delayed fluorescence compound PL is less than or equal to 45 nm.

[0171] According to one embodiment of the present invention, wherein the full width at half maximum FWHM- in the photoluminescence spectrum of the thermally activated delayed fluorescence compound PL is less than or equal to 35 nm.

[0172] According to one embodiment of the present invention, wherein the full width at half maximum FWHM- in the photoluminescence spectrum of the thermally activated delayed fluorescence compound PL is less than or equal to 25 nm.

[0173] According to one embodiment of the present invention, wherein the full width at half maximum FWHM- in the photoluminescence spectrum of the thermally activated delayed fluorescence compound PL is less than or equal to 20 nm.

[0174] In the present invention, the test methods for the maximum emission wavelength λ max-PL and the full width at half maximum FWHM- PL are as follows:

[0175] The photoluminescence spectrum (PL) data of the compound to be measured was determined using a fluorescence spectrophotometer model F98 produced by Shanghai Lengguang Technology Co., Ltd. The compound to be measured was dissolved in toluene solvent to prepare a solution with a concentration of 1×10 -6 mol / L. Nitrogen was passed through the prepared solution to remove oxygen for 5 minutes. The solution to be measured was loaded into a quartz sample tube and excited with light of 350 nm wavelength at room temperature (298 K) to measure its emission spectrum. The emission spectrum has a maximum emission wavelength λ max-PL and full width at half maximum FWHM- PL (that is, the peak width at half of the maximum emission peak height. A straight line parallel to the horizontal axis is drawn through the midpoint of the peak height, and the distance between the two intersection points of this straight line and the two sides of the peak).

[0176] As an example, the maximum emission wavelength λ max-PL and full width at half maximum FWHM- PL data of the photoluminescence spectrum of the following thermally activated delayed fluorescence compounds were determined by the above method. The specific results are shown in Table 1:

[0177] Table 1 Maximum emission wavelength and full width at half maximum of the photoluminescence spectrum of the compound

[0178] Compound number <![CDATA[λ max-PL (nm)]]> <![CDATA[FWHM- PL (nm)]]> BD2 459 25.3 BD44 466 18.7 .

[0179] According to an embodiment of the present invention, the platinum metal complex has a structure represented by Formula 2:

[0180]

[0181] In Formula 2,

[0182] Ring F, Ring G, Ring H and Ring I are each independently selected from an unsaturated carbocyclic ring having 5-30 carbon atoms, an unsaturated heterocyclic ring having 1-30 carbon atoms, or a combination thereof;

[0183] f is selected from 0 or 1;

[0184] A1 - A4 are the same or different each time they appear and are independently selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , (CR q R q ) y , a substituted or unsubstituted arylene having 6-30 carbon atoms, a substituted or unsubstituted heteroarylene having 3-30 carbon atoms, or a combination thereof; y is the same or different each time it appears and is independently selected from 1, 2, 3, 4 or 5;

[0185] X1 - X4 are each independently selected from C or N;

[0186] K1 - K4 are each independently selected from a single bond, O or S;

[0187] R n each occurrence, is the same as or different from the others and represents mono - substitution, poly - substitution or no substitution;

[0188] R q ,R n each occurrence, is the same as or different from the others and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 - 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 - 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 - 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 - 20 ring atoms, substituted or unsubstituted aralkyl having 7 - 30 carbon atoms, substituted or unsubstituted alkoxy having 1 - 20 carbon atoms, substituted or unsubstituted aryloxy having 6 - 30 carbon atoms, substituted or unsubstituted alkenyl having 2 - 20 carbon atoms, substituted or unsubstituted alkynyl having 2 - 20 carbon atoms, substituted or unsubstituted aryl having 6 - 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 - 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 - 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 - 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 - 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 - 20 carbon atoms, substituted or unsubstituted amino having 0 - 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0189] adjacent substituents R q ,R n the substituents can optionally be linked to form a ring.

[0190] In this embodiment, "adjacent substituents R q ,R n can optionally be linked to form a ring" is intended to mean that among adjacent substituent groups, for example, between two substituents R q ,between two substituents R n ,and between substituent R q and R n ,any one or more of these adjacent substituent groups can be linked to form a ring. Obviously, these adjacent substituent groups can also all not be linked to form a ring.

[0191] According to one embodiment of the present invention, the platinum metal complex has a structure represented by Formula 2 - 1:

[0192]

[0193] In Formula 2-1,

[0194] Ring F, Ring G, and Ring H are each independently selected from an unsaturated carbocyclic ring having 5 to 30 carbon atoms, an unsaturated heterocyclic ring having 3 to 30 carbon atoms, or a combination thereof; Ring I is selected from an unsaturated heterocyclic ring having 1 to 30 carbon atoms;

[0195] A3 and A4 are each independently selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , (CR q R q ) y , a substituted or unsubstituted arylene having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof; y is the same or different each time it appears and is selected from 1, 2, 3, 4, or 5;

[0196] K1-K4 are each independently selected from a single bond, O, or S;

[0197] X1-X3 are each independently selected from C or N;

[0198] R n is the same or different each time it appears and is represented as mono-substituted, multi-substituted, or unsubstituted;

[0199] R, R q , R nEach occurrence is the same or different and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0200] Adjacent substituents R, R q , R n can optionally be linked to form a ring.

[0201] In this embodiment, "adjacent substituents R, R q , R n can optionally be linked to form a ring" is intended to mean that among the adjacent substituent groups, for example, between two substituents R q , between two substituents R n , between substituent R q and R n , and between substituent R and R n , any one or more of these adjacent substituent groups can be linked to form a ring. Obviously, none of these adjacent substituent groups can also be linked to form a ring.

[0202] According to one embodiment of the present invention, wherein the platinum metal complex has a structure represented by the general formula Pt(L a )(L b ), wherein L a and L b are the first ligand and the second ligand coordinated with the metal Pt respectively, and the L a has a structure represented by formula A: wherein "#" in formula A represents the position connected to L b ; the L b has a structure represented by formula B: wherein in formula B represents the position connected to L a

[0203] According to an embodiment of the present invention, wherein the ring F, ring G, and ring H are each independently selected from a five-membered unsaturated carbon ring, an aromatic ring having 6 - 30 carbon atoms, or a heteroaromatic ring having 3 - 30 carbon atoms; each occurrence of ring I is the same or different and is selected from an unsaturated heterocyclic ring having 3 - 30 carbon atoms.

[0204] According to an embodiment of the present invention, wherein the ring F, ring G, and ring H are each independently selected from a five-membered unsaturated carbon ring, an aromatic ring having 6 - 18 carbon atoms, or a heteroaromatic ring having 3 - 18 carbon atoms; each occurrence of ring I is the same or different and is selected from an unsaturated heterocyclic ring having 3 - 18 carbon atoms.

[0205] According to an embodiment of the present invention, wherein the ring F, ring G, and ring H are each independently selected from a benzene ring, a pyridine ring, an indene ring, a fluorene ring, an indole ring, a carbazole ring, a benzofuran ring, a dibenzofuran ring, a benzosilole ring, a dibenzosilole ring, a benzothiophene ring, a dibenzothiophene ring, a dibenzoselenophene ring, a cyclopentadiene ring, a furan ring, a thiophene ring, or a silole ring; each occurrence of the ring I is the same or different and is selected from an imidazolium carbene ring or a benzimidazolium carbene ring.

[0206] According to an embodiment of the present invention, wherein the K1 - K4 are selected from single bonds.

[0207] According to an embodiment of the present invention, wherein the platinum metal complex has a structure represented by one of formulas 3 - 1 to 3 - 18:

[0208]

[0209]

[0210]

[0211] wherein,

[0212] each occurrence of A4 is the same or different and is selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , a substituted or unsubstituted arylene having 6 - 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 - 30 carbon atoms, or a combination thereof; each occurrence of y is the same or different and is selected from 1, 2, or 3;

[0213] U1 - U 20 each occurrence is the same or different and is selected from CR​n or N;

[0214] R u each occurrence is the same as or different from the others and is represented as mono-substituted, multi-substituted or unsubstituted;

[0215] R, R N , R q , R u and R n each occurrence is the same as or different from the others and is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 - 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 - 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 - 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 - 20 ring atoms, substituted or unsubstituted aralkyl having 7 - 30 carbon atoms, substituted or unsubstituted alkoxy having 1 - 20 carbon atoms, substituted or unsubstituted aryloxy having 6 - 30 carbon atoms, substituted or unsubstituted alkenyl having 2 - 20 carbon atoms, substituted or unsubstituted alkynyl having 2 - 20 carbon atoms, substituted or unsubstituted aryl having 6 - 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 - 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 - 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 - 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 - 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 - 20 carbon atoms, substituted or unsubstituted amino having 0 - 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0216] adjacent substituents R, R N , R q , R u and R n can optionally be linked to form a ring.

[0217] In this embodiment, "adjacent substituents R, R N , R q , R u and R n can optionally be linked to form a ring" is intended to mean that among adjacent substituent groups, for example, between two substituents R q s, between two substituents R u s, between two substituents R n s, between substituent R and R u s, between substituent R and R n s, between substituent R N and R n s, and between substituent R q and R nAmong them, any one or more of these adjacent substituent groups can be connected to form a ring. Obviously, these adjacent substituent groups may also not be connected to form a ring at all.

[0218] According to one embodiment of the present invention, the platinum metal complex has a structure represented by Formula 3-1 or Formula 3-2.

[0219] According to one embodiment of the present invention, A4 is selected from a single bond, O or S.

[0220] According to one embodiment of the present invention, A4 is selected from O.

[0221] According to one embodiment of the present invention, U1-U 20 are the same or different each time they appear and are selected from CR n ; and the R n are the same or different each time they appear and are selected from the group consisting of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, and combinations thereof.

[0222] According to one embodiment of the present invention, the R n are the same or different each time they appear and are selected from the group consisting of hydrogen, deuterium, fluorine, methyl, deuterated methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, phenyl, trimethylsilyl, carbazolyl, indolyl, benzofuranyl, dibenzofuranyl, benzosilolyl, dibenzosilolyl, benzothiophenyl, dibenzothiophenyl, dibenzoselenophenyl, and combinations thereof.

[0223] According to one embodiment of the present invention, the substituent R has a structure represented by Formula 4:

[0224]

[0225] In Formula 4,

[0226] ring M and ring W are the same or different each time they appear and are selected from unsaturated carbocycles having 5-30 carbon atoms, unsaturated heterocycles having 3-30 carbon atoms, or combinations thereof;

[0227] X5-X8 are the same or different each time they appear and are selected from C or N;

[0228] "*" represents the connection position of Formula 4;

[0229] R m ,R w is the same or different each time it appears and represents mono-substitution, multi-substitution or no substitution;

[0230] R m and R w are each the same or different each time they appear and are selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0231] Adjacent substituents R m ,R w can optionally be linked to form a ring.

[0232] In this embodiment, "adjacent substituents R m ,R w can optionally be linked to form a ring" is intended to mean that among the adjacent substituent groups, for example, between two substituents R m , between two substituents R w , and between substituent R m and R w , any one or more of these adjacent substituent groups can be linked to form a ring. Obviously, these adjacent substituent groups can also not be linked to form a ring.

[0233] According to one embodiment of the present invention, wherein the substituent R has a structure represented by Formula 4-1:

[0234]

[0235] In Formula 4-1,

[0236] M1 to M 10 are each independently selected from CR m or N;

[0237] W1 to W3 are each independently selected from CR w or N;

[0238] R m and R w each occurrence is the same as or different from and is selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0239] Adjacent substituents R m and R w can optionally be joined to form a ring.

[0240] According to one embodiment of the present invention, at least one R in the formula 4 or formula 4-1 wselected from the group consisting of: deuterium, halogen, substituted or unsubstituted alkyl having 1 - 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 - 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 - 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 - 20 ring atoms, substituted or unsubstituted aralkyl having 7 - 30 carbon atoms, substituted or unsubstituted alkoxy having 1 - 20 carbon atoms, substituted or unsubstituted aryloxy having 6 - 30 carbon atoms, substituted or unsubstituted alkenyl having 2 - 20 carbon atoms, substituted or unsubstituted alkynyl having 2 - 20 carbon atoms, substituted or unsubstituted aryl having 6 - 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 - 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 - 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 - 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 - 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 - 20 carbon atoms, substituted or unsubstituted amino having 0 - 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0241] According to one embodiment of the present invention, wherein said M1 to M 10 are each independently selected from CR m .

[0242] According to one embodiment of the present invention, wherein said W1 to W3 are each independently selected from CR w .

[0243] According to one embodiment of the present invention, wherein said R m and R w are each independently the same or different and are selected from the group consisting of: hydrogen, deuterium, halogen, cyano, hydroxyl, mercapto, substituted or unsubstituted alkyl having 1 - 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 - 20 ring carbon atoms, substituted or unsubstituted aryl having 6 - 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 - 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 - 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 - 20 carbon atoms, and combinations thereof.

[0244] According to one embodiment of the present invention, wherein said M1 to M 10 are selected from CH or CD.

[0245] According to one embodiment of the present invention, wherein said W2 is selected from CR w , said R wSelected from the group consisting of: deuterium, halogen, cyano, hydroxyl, mercapto, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, and combinations thereof.

[0246] According to one embodiment of the present invention, wherein the platinum metal complex has a structure represented by Pt(L a )(L b ), wherein L a and L b are respectively the first ligand and the second ligand coordinated with the metal Pt, and the L a is selected from the group consisting of L a 1-1 to L a 1-25 and L a 2-1 to L a 2-6, and the L b is selected from the group consisting of L b 1-1 to L b 1-8 and L b 2-1 to L b 2-22. The specific structures of the L a 1-1 to L a 1-25, L a 2-1 to L a 2-6, L b 1-1 to L b 1-8 and L b 2-1 to L b 2-22 are shown in claim 14.

[0247] According to one embodiment of the present invention, wherein the platinum metal complex is selected from the group consisting of Pt1 to Pt81, and the Pt1 to Pt81 have a structure represented by Pt(L a )(L b ). The specific structures of the Pt1 to Pt81 are shown in claim 14.

[0248] According to one embodiment of the present invention, wherein the first host compound has a structure represented by one of Formula 5 to Formula 7:

[0249]

[0250] In Formula 5, Z1 to Z3 are each independently selected from CR4 or N, and at least one of Z1 to Z3 is N;

[0251] L is the same or different each time it appears and is selected from the group consisting of: a single bond, a substituted or unsubstituted arylene having 6 - 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 - 30 carbon atoms, and combinations thereof;

[0252] In Formulas 6 and 7, Z4 is the same or different each time it appears and is selected from CR4 or N, and at least one Z4 is N;

[0253] Z is the same or different each time it appears and is selected from O or S;

[0254] R1 - R4 are the same or different each time they appear and are selected from the group consisting of: hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl having 1 - 20 carbon atoms, a substituted or unsubstituted cycloalkyl having 3 - 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl having 1 - 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 - 20 ring atoms, a substituted or unsubstituted aralkyl having 7 - 30 carbon atoms, a substituted or unsubstituted alkoxy having 1 - 20 carbon atoms, a substituted or unsubstituted aryloxy having 6 - 30 carbon atoms, a substituted or unsubstituted alkenyl having 2 - 20 carbon atoms, a substituted or unsubstituted alkynyl having 2 - 20 carbon atoms, a substituted or unsubstituted aryl having 6 - 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 - 30 carbon atoms, a substituted or unsubstituted alkylsilyl having 3 - 20 carbon atoms, a substituted or unsubstituted arylsilyl having 6 - 20 carbon atoms, a substituted or unsubstituted alkylgermyl having 3 - 20 carbon atoms, a substituted or unsubstituted arylgermyl having 6 - 20 carbon atoms, a substituted or unsubstituted amino having 0 - 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0255] Adjacent substituents R4 can optionally be joined to form a ring.

[0256] In this context, "adjacent substituents R4 can optionally be joined to form a ring" is intended to mean that a ring can be formed by joining two adjacent substituents R4. Obviously, two adjacent substituents R4 may also not be joined to form a ring.

[0257] According to one embodiment of the present invention, the first host compound has a structure represented by Formula 5 - 1 or Formula 6 - 1:

[0258]

[0259] In Formula 5 - 1,

[0260] R1 and R2 are each independently selected from substituted or unsubstituted heteroaryls having 3 - 30 carbon atoms;

[0261] L is selected from a single bond, a substituted or unsubstituted arylene having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof;

[0262] In Formula 6-1,

[0263] Z is selected from O or S;

[0264] Z 41 -Z 48 is the same or different each occurrence and is selected from CR4, CR4', or N, and Z 41 -Z 48 at least one of which is selected from N and at least one of which is selected from CR4';

[0265] R4' is the same or different each occurrence and is selected from a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, or a combination thereof;

[0266] R L , and R4 is the same or different each occurrence and is selected from the group consisting of hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, a substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0267] Adjacent substituents R4 can optionally be joined to form a ring.

[0268] According to one embodiment of the present invention, wherein said L is the same or different each occurrence and is selected from the group consisting of a single bond, a substituted or unsubstituted arylene having 6 to 18 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 18 carbon atoms, and combinations thereof.

[0269] According to one embodiment of the present invention, wherein each occurrence of L is the same or different and is selected from the group consisting of: a single bond, a phenylene group, a biphenylene group, a fluorenylene group, a tritylene group, a furylene group, a thiophene group, a dibenzofurylene group, a dibenzothiophene group, and combinations thereof.

[0270] According to one embodiment of the present invention, wherein said R L Each occurrence is the same or different and is selected from the group consisting of: a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and combinations thereof.

[0271] According to one embodiment of the present invention, wherein said R L Each occurrence is the same or different and is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0272] According to one embodiment of the present invention, wherein said R L Each occurrence is the same or different and is selected from the group consisting of: a phenyl group, a biphenyl group, a trityl group, an indenyl group, a fluorenyl group, an indolyl group, a carbazolyl group, a benzofuryl group, a dibenzofuryl group, a benzosilolyl group, a dibenzosilolyl group, a benzothiophenyl group, a dibenzothiophenyl group, a dibenzoselenophenyl group, and combinations thereof.

[0273] According to one embodiment of the present invention, wherein each occurrence of R1 to R4 is the same or different and is selected from the group consisting of: hydrogen, deuterium, a halogen, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and combinations thereof.

[0274] According to one embodiment of the present invention, wherein each occurrence of R1 to R4 is the same or different and is selected from the group consisting of: hydrogen, deuterium, a halogen, a cyano group, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 18 carbon atoms, and combinations thereof.

[0275] According to one embodiment of the present invention, wherein each occurrence of R1 to R4 is the same or different and is selected from the group consisting of: hydrogen, deuterium, fluorine, a cyano group, a phenyl group, a biphenyl group, a trityl group, an indenyl group, a fluorenyl group, an indolyl group, a carbazolyl group, a benzofuryl group, a dibenzofuryl group, a benzosilolyl group, a dibenzosilolyl group, a benzothiophenyl group, a dibenzothiophenyl group, a dibenzoselenophenyl group, a triazinyl group, and combinations thereof.

[0276] According to one embodiment of the present invention, in Formula 6-1, the Z 41 -Z 48 at least one is selected from N, and at least two are selected from CR4'.

[0277] According to one embodiment of the present invention, in Formula 6-1, the Z 41 -Z 48 only one is selected from N, and only two are selected from CR4'.

[0278] According to one embodiment of the present invention, in Formula 6-1, the Z 42 is selected from N, and the Z 41 and Z 46 are selected from CR4'.

[0279] According to one embodiment of the present invention, wherein the first host compound is selected from the group consisting of Compound N-1-1 to Compound N-1-60, Compound N-2-1 to Compound N-2-35, and Compound N-3-1 to Compound N-3-9. The specific structures of Compound N-1-1 to Compound N-1-60, Compound N-2-1 to Compound N-2-35, and Compound N-3-1 to Compound N-3-9 are shown in Claim 15.

[0280] According to one embodiment of the present invention, wherein the hydrogen in the structures of Compound N-1-1 to Compound N-1-53, Compound N-1-58, Compound N-2-1 to Compound N-2-32, and Compound N-3-1 to Compound N-3-7 can be partially or completely replaced by deuterium.

[0281] According to one embodiment of the present invention, wherein the second host compound has a structure represented by Formula 8:

[0282]

[0283] In Formula 8,

[0284] L 11 is selected from a single bond, a substituted or unsubstituted arylene having 6-30 carbon atoms, a substituted or unsubstituted heteroarylene having 3-30 carbon atoms, or a combination thereof;

[0285] Ar 11 is selected from a substituted or unsubstituted aryl having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl having 3-30 carbon atoms, a substituted or unsubstituted amino having 0-30 carbon atoms, or a combination thereof;

[0286] R6 is the same or different each time it appears and represents single substitution, multiple substitution, or no substitution;

[0287] R6, each occurrence of which is the same as or different from one another, is selected from the group consisting of: hydrogen, deuterium, a halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxyl group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0288] Adjacent substituents R6 can optionally be joined to form a ring.

[0289] As used herein, the phrase “adjacent substituents R6 can optionally be joined to form a ring” is intended to mean that two adjacent substituents R6 can be joined to form a ring. Obviously, two adjacent substituents R6 may also not be joined to form a ring.

[0290] According to one embodiment of the present invention, the second host compound has a structure represented by Formula 8-1 or Formula 8-2:

[0291]

[0292] L 11 ,L 12 is selected from a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms, or a combination thereof;

[0293] Ar 11 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted amino group having 0 to 30 carbon atoms, or a combination thereof;

[0294] R6, each occurrence of which is the same as or different from one another, represents mono-substitution, multi-substitution or no substitution;

[0295] Each occurrence of R6 is the same as or different from and is selected from the group consisting of hydrogen, deuterium, a halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxyl group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0296] Adjacent substituents R6 can optionally be joined to form a ring.

[0297] According to one embodiment of the present invention, the second host compound has a structure represented by Formula 8-3 or Formula 8-4:

[0298]

[0299] Ar 11 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted amino group having 0 to 30 carbon atoms, or combinations thereof;

[0300] L 11 is selected from a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms, or combinations thereof;

[0301] Each occurrence of R6 is the same as or different from and represents mono-substituted, multi-substituted or unsubstituted;

[0302] Each occurrence of R6 is the same as or different from one another and is independently selected from the group consisting of: hydrogen, deuterium, a halogen, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, a substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0303] Adjacent substituents R6 can optionally be joined to form a ring.

[0304] According to one embodiment of the present invention, each occurrence of R6 is the same as or different from one another and is independently selected from the group consisting of: hydrogen, deuterium, a halogen, cyano, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, and combinations thereof.

[0305] According to one embodiment of the present invention, each occurrence of R6 is the same as or different from one another and is independently selected from the group consisting of: hydrogen, deuterium, a halogen, cyano, a substituted or unsubstituted aryl having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 18 carbon atoms, and combinations thereof.

[0306] According to one embodiment of the present invention, each occurrence of R6 is the same as or different from one another and is independently selected from the group consisting of: hydrogen, deuterium, fluorine, cyano, phenyl, biphenyl, triphenylene, indenyl, fluorenyl, indolyl, carbazolyl, benzofuranyl, dibenzofuranyl, benzosilolyl, dibenzosilolyl, benzothiophenyl, dibenzothiophenyl, dibenzoselenophenyl, and combinations thereof.

[0307] According to an embodiment of the present invention, wherein the second host compound is selected from the group consisting of Compound P-1 to Compound P-39, and the specific structures of Compound P-1 to Compound P-39 are shown in Claim 16.

[0308] According to an embodiment of the present invention, wherein the hydrogen in the structures of Compound P-1 to Compound P-23 and Compound P-27 to Compound P-39 can be partially or completely replaced by deuterium.

[0309] According to an embodiment of the present invention, wherein the first host compound and the second host compound are host materials, the platinum metal complex is a phosphorescent sensitizer, and the thermally activated delayed fluorescence compound is a luminescent material.

[0310] According to an embodiment of the present invention, wherein the proportion of the first host compound and the second host compound in the total weight of the luminescent layer material is 65%-98.9%, the proportion of the platinum metal complex in the total weight of the luminescent layer material is 1%-30%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer material is 0.1%-5%.

[0311] According to an embodiment of the present invention, wherein the proportion of the first host compound and the second host compound in the total weight of the luminescent layer material is 82%-94.5%, the proportion of the platinum metal complex in the total weight of the luminescent layer material is 5%-15%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer material is 0.5%-3%.

[0312] According to an embodiment of the present invention, wherein the proportion of the first host compound and the second host compound in the total weight of the luminescent layer material is 86.5%-91.5%, the proportion of the platinum metal complex in the total weight of the luminescent layer material is 8%-12%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer material is 0.5%-1.5%.

[0313] According to an embodiment of the present invention, wherein the polymer contained in the first organic layer is itself a polymer before the manufacture of the organic electroluminescent device.

[0314] According to an embodiment of the present invention, wherein the polymer contained in the first organic layer is itself a polymerizable monomer before the manufacture of the organic electroluminescent device, and the polymerizable monomer undergoes a post-polymerization process during the manufacture of the organic electroluminescent device to form the polymer.

[0315] According to an embodiment of the present invention, wherein the polymer can also undergo an annealing crosslinking process during the manufacture of the organic electroluminescent device.

[0316] According to an embodiment of the present invention, the molecular weight of the polymer contained in the first organic layer is 10,000 - 200,000; preferably, the molecular weight is 50,000 - 150,000; more preferably, the molecular weight is 80,000 - 110,000.

[0317] According to an embodiment of the present invention, the first organic layer is a hole injection layer, the polymer is a polymer having hole transport / hole injection properties, and the hole injection layer can be formed of the polymer or may further contain a p-type dopant.

[0318] In this embodiment, the organic electroluminescent device may further include a second organic layer, the second organic layer is a hole transport layer, the second organic layer contains a second polymer, and the second polymer may be the same as or different from the polymer in the first organic layer.

[0319] According to an embodiment of the present invention, the first organic layer may also be a hole transport layer, the polymer is a polymer having hole transport properties, the organic electroluminescent device may further include a second organic layer, the second organic layer is a hole injection layer, the second organic layer contains a second polymer, and the second polymer is a polymer having hole transport / hole injection properties; preferably, the second organic layer further contains a p-type dopant. Preferably, the p-type dopant is an ionic dopant.

[0320] According to an embodiment of the present invention, the polymer contains a triarylamine structure, and the polymer may contain a crosslinking group. The crosslinking group is well-known in the art. Preferably, the crosslinking group is selected from the group consisting of: substituted or unsubstituted vinyl, substituted or unsubstituted styryl, substituted or unsubstituted acrylate, substituted or unsubstituted methacrylate, substituted or unsubstituted epoxide, substituted or unsubstituted oxetane, substituted or unsubstituted benzocyclobutene, substituted or unsubstituted siloxane, substituted or unsubstituted maleimide, and combinations thereof.

[0321] According to an embodiment of the present invention, the p-type dopant contains a fluorine atom.

[0322] According to an embodiment of the present invention, the p-type dopant has a structure represented by Formula 9:

[0323]

[0324] In Formula 9,

[0325] Ar aeach independently, when it appears, is selected from a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3-20 ring carbon atoms, a substituted or unsubstituted alkenyl group having 2-20 carbon atoms, a hydroxyl group, a mercapto group, a substituted or unsubstituted aryl group having 6-30 carbon atoms, or a combination thereof;

[0326] Ar b1 and Ar b2 each independently is selected from a substituted or unsubstituted aryl group having 6-30 carbon atoms;

[0327] g and k each independently are selected from integers from 0 to 5;

[0328] F4 means substituted with 4 fluorine atoms;

[0329] F 5-g means substituted with 5-g fluorine atoms;

[0330] k + g ≥ 1.

[0331] According to one embodiment of the present invention, wherein the p-type dopant is selected from the group consisting of Compound HI-1 to Compound HI-14:

[0332]

[0333]

[0334]

[0335]

[0336] According to one embodiment of the present invention, wherein the first organic layer is prepared by a solution method.

[0337] According to one embodiment of the present invention, wherein the organic electroluminescent device includes an anode, a cathode, a light-emitting layer disposed between the anode and the cathode, and a first organic layer and a second organic layer disposed between the anode and the light-emitting layer, and the light-emitting layer, the first organic layer, and the second organic layer are all prepared by a solution method.

[0338] According to one embodiment of the present invention, wherein the organic electroluminescent device emits blue light.

[0339] According to one embodiment of the present invention, a display device is disclosed, which includes the organic electroluminescent device according to any one of the above embodiments.

[0340] According to an embodiment of the present invention, an organic light-emitting ink is disclosed, which comprises a solvent, a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound, and the first host compound, the second host compound, the platinum metal complex, and the thermally activated delayed fluorescence compound are as shown in any of the above embodiments.

[0341] According to an embodiment of the present invention, in the organic light-emitting ink, the total content of the first host compound, the second host compound, the platinum metal complex, and the thermally activated delayed fluorescence compound ranges from 0.5 wt% to 7.5 wt%, and the content of the solvent ranges from 92.5 wt% to 99.5 wt%.

[0342] According to an embodiment of the present invention, the boiling point of the solvent is 100 °C to 350 °C.

[0343] According to an embodiment of the present invention, in the organic light-emitting ink, the solvent is selected from at least one solvent in the group consisting of ether solvents, ester solvents, and alkyl-substituted aromatic benzene solvents.

[0344] According to an embodiment of the present invention, in the organic light-emitting ink, the solvent is selected from two or more solvents in the group consisting of ether solvents, ester solvents, and alkyl-substituted aromatic benzene solvents.

[0345] According to an embodiment of the present invention, the ether solvents are selected from the group consisting of: anisole, phenetole, 3-phenoxytoluene, 2,5-dimethoxytoluene, 4-ethylphenetole, 1,3-dimethoxybenzene, dibenzyl ether, 1,2-dimethoxybenzene, 1-methoxynaphthalene, diphenyl ether, 2-phenoxymethyl ether.

[0346] According to an embodiment of the present invention, the ester solvent is a benzoate solvent.

[0347] According to an embodiment of the present invention, the benzoate solvents are selected from the group consisting of: methyl benzoate, ethyl benzoate, ethyl p-methylbenzoate, isobutyl benzoate, ethylhexyl benzoate.

[0348] According to an embodiment of the present invention, the alkyl-substituted aromatic benzene solvents are selected from the group consisting of: cyclohexylbenzene, 1-hexylbenzene, 1-heptylbenzene, 1-octylbenzene, 1-decylbenzene, 4,4'-diethylbiphenyl, 3,4'-diisopropylbiphenyl, 4,4'-diisopropylbiphenyl.

[0349] According to an embodiment of the present invention, in the organic electroluminescent device, the light-emitting layer is prepared by a solution method using the organic light-emitting ink.

[0350] Combined with other materials

[0351] The materials for specific layers in the organic light-emitting devices described in the present invention can be used in combination with various other materials present in the devices. The combinations of these materials are described in detail in paragraphs 0132-0161 of US Patent Application US2016 / 0359122A1, the entire content of which is incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0352] The materials described herein as being useful for specific layers in organic light-emitting devices can be used in combination with a variety of other materials present in the devices. For example, the compounds disclosed herein can be used in combination with a variety of hosts, transport layers, blocking layers, injection layers, electrodes, and other layers that may be present. The combinations of these materials are described in detail in paragraphs 0080-0101 of US Patent Application US2015 / 0349273A1, the entire content of which is incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0353] The first host compound, the second host compound, the platinum metal complex, and the thermally activated delayed fluorescence compound used in the present invention can be easily obtained by referring to the preparation methods in the prior art, and the preparation methods are not described herein again.

[0354] The preparation method of the organic electroluminescent device is not limited. The preparation method in the following examples is only an example and should not be construed as a limitation. Those skilled in the art can reasonably improve the preparation method of the following examples based on the prior art. Exemplarily, the ratio of various materials in the light-emitting layer is not particularly limited, and those skilled in the art can reasonably select within a certain range according to the prior art. For example, based on the total weight of the light-emitting layer materials, two host compounds can account for 65%-98.9%, the platinum metal complex can account for 1%-30%, and the thermally activated delayed fluorescence compound can account for 0.1%-5%; or two host compounds can account for 82%-94.5%, the platinum metal complex can account for 5%-15%, and the thermally activated delayed fluorescence compound can account for 0.5%-3%; or two host compounds can account for 86.5%-91.5%, the platinum metal complex can account for 8%-12%, and the thermally activated delayed fluorescence compound can account for 0.5%-1.5%. In addition, the ratio of the two host compounds can be 99:1 to 1:99; or, or the ratio can be 80:20 to 20:80; or the ratio can be 70:30 to 30:70. In the device examples, the characteristics of the device are also tested using conventional equipment in the art (including but not limited to the evaporation coater produced by Angstrom Engineering, the optical test system and life test system produced by Suzhou FushiDa, the ellipsometer produced by Beijing Liangtuo, etc.) by methods well-known to those skilled in the art.

[0355] Device Example

[0356] The first organic layer of the organic electroluminescent device of the present invention contains a polymer, so it cannot be prepared by evaporation coating and must be prepared by solution coating. The preparation method of the organic electroluminescent device of the present invention can refer to the common methods in the prior art. For example, it can refer to the prior art CN116023402A, CN115440903A and CN108884114A, and is completed by combining the solution coating process and the evaporation coating process: the hole injection layer, hole transport layer and light-emitting layer are prepared by the common solution coating method in the prior art, and the hole blocking layer, electron transport layer, electron injection layer and cathode are prepared by the common evaporation coating method in the prior art. The following provides an exemplary and non-limiting preparation method of the organic electroluminescent device of the present invention. Taking Device Example 1 as an example, it is specifically as follows:

[0357] (1) Substrate treatment: Clean the glass substrate with a thick indium tin oxide (ITO) anode, and then treat it with oxygen plasma and UV ozone. After treatment, dry the substrate in a glove box to remove moisture for standby.

[0358] (2) Preparation of the hole injection layer: Dissolve compound HT and compound HI-14 in butyl benzoate to obtain a prepared solution (the weight ratio of compound HT to compound HI-14 is 5:1). Spin-coat the solution on the above substrate and remove the solvent by heating to prepare a uniform thin film with a thickness of

[0359] (3) Preparation of the hole transport layer: Dissolve compound HT1 in cyclohexylbenzene to obtain a prepared solution. Spin-coat the solution on the above hole injection layer and remove the solvent by heating to prepare a uniform thin film with a thickness of

[0360] (4) Preparation of the light-emitting layer: Dissolve the first host compound N-1-15, the second host compound P-22, the platinum metal complex Pt27 as a phosphorescent sensitizer, and the thermally activated delayed fluorescence compound BD2 in methyl benzoate to obtain a prepared solution. The weight ratio of compound N-1-15: compound P-22: platinum metal complex Pt27: compound BD2 is 62.3:26.7:10:1. Spin-coat the solution on the above hole transport layer and remove the solvent by heating to prepare a uniform thin film with a thickness of

[0361] (5) Preparation of the hole blocking layer, electron transport layer, electron injection layer, and cathode: Evaporate compound N-3-2 as the hole blocking layer on the above light-emitting layer with a thickness of Co-evaporate compound ET and lithium 8-hydroxyquinoline (Liq) as the electron transport layer on the hole blocking layer. The weight ratio of compound ET to Liq is 40:60, and the thickness is Evaporate LiF with a thickness of as the electron injection layer on the electron transport layer, and continue to evaporate Aluminum with a thickness of as the cathode.

[0362] Finally, transfer the device back to the glove box and encapsulate it with a glass cover and a desiccant to complete the device.

[0363] Device Example 2

[0364] The preparation method of Device Example 2 is the same as that of Device Example 1, except that platinum metal complex Pt11 is used instead of platinum metal complex Pt27 in the light-emitting layer (EML).

[0365] Device Example 3

[0366] The preparation method of Device Example 3 is the same as that of Device Example 1, except that compound BD44 is used instead of compound BD2 in the light-emitting layer (EML).

[0367] Device Example 4

[0368] The preparation method of Device Example 4 is the same as that of Device Example 3, except that platinum metal complex Pt11 is used instead of platinum metal complex Pt27 in the emitting layer (EML).

[0369] Device Example 5

[0370] The preparation method of Device Example 5 is the same as that of Device Example 1, except that compound N-3-2 is used instead of compound N-1-15 in the emitting layer (EML).

[0371] Device Example 6

[0372] The preparation method of Device Example 6 is the same as that of Device Example 5, except that platinum metal complex Pt11 is used instead of platinum metal complex Pt27 in the emitting layer (EML).

[0373] Device Example 7

[0374] The preparation method of Device Example 7 is the same as that of Device Example 5, except that compound BD44 is used instead of compound BD2 in the emitting layer (EML).

[0375] Device Example 8

[0376] The preparation method of Device Example 8 is the same as that of Device Example 7, except that platinum metal complex Pt11 is used instead of platinum metal complex Pt27 in the emitting layer (EML).

[0377] Device Comparative Example 1

[0378] The preparation method of Device Comparative Example 1 is the same as that of Device Example 1, except that only the first host compound N-1-15, the second host compound P-22, and the thermally activated delayed fluorescence compound BD2 are used as the emitting layer (EML), and the weight ratio of compound N-1-15: compound P-22: compound BD2 is 69.3:29.7:1.

[0379] Device Comparative Example 2

[0380] The preparation method of Device Comparative Example 2 is the same as that of Device Comparative Example 1, except that compound BD44 is used instead of compound BD2 in the emitting layer (EML).

[0381] Device Comparative Example 3

[0382] The preparation method of Device Comparative Example 3 is the same as that of Device Comparative Example 1, except that compound N-3-2 is used instead of compound N-1-15 in the emitting layer (EML).

[0383] Device Comparative Example 4

[0384] The preparation method of Device Comparative Example 4 is the same as that of Device Comparative Example 3, except that Compound BD44 is used instead of Compound BD2 in the emitting layer (EML).

[0385] The material structures used in the above devices are as follows:

[0386]

[0387]

[0388] The CIEE values, maximum emission wavelength (λ 2 ), full width at half maximum (FWHM), and external quantum efficiency (EQE) of Examples 1-8 and Comparative Examples 1-4 were measured at 1000 cd / m max . To more intuitively show the comparison of the data, the external quantum efficiency of Comparative Example 1 was set to 1.00, and the external quantum efficiencies of Examples 1-8 and Comparative Examples 2-4 were converted relative to the corresponding data of Comparative Example 1. The relevant data are shown in Table 2.

[0389] Table 2 Device Data

[0390]

[0391]

[0392] In Examples 1-2 and Comparative Example 1, Compound BD2 was used as the emitting material in the emitting layer. The difference is only that Examples 1-2 used a platinum metal complex as the phosphorescent sensitizer, while Comparative Example 1 did not use a platinum metal complex. Compared with Comparative Example 1, the maximum emission wavelength of Examples 1-2 is basically the same as that of Comparative Example 1, the full width at half maximum is basically the same as that of Comparative Example 1 and both have a narrow full width at half maximum, but importantly, the external quantum efficiency (EQE) was increased by 1.41 and 1.37 times respectively. Similarly, in Examples 3-4 and Comparative Example 2, Compound BD44 was used as the emitting material in the emitting layer. The difference is only whether a platinum metal complex was used as the phosphorescent sensitizer. Compared with Comparative Example 2, the maximum emission wavelength of Examples 3-4 is the same as that of Comparative Example 2, the full width at half maximum is basically the same as that of Comparative Example 2 and both have a narrow full width at half maximum, but the EQE was increased by 53% in both cases. These data prove that for the organic electroluminescent device of the present invention which includes a polymer in the hole injection layer and the hole transport layer, and includes a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound represented by the structure of Formula 1 in the emitting layer, compared with a conventional TADF device without a platinum metal complex as the phosphorescent sensitizer, it can maintain a narrow full width at half maximum and significantly improve the device efficiency, showing very excellent device performance.

[0393] After replacing the first host compound, the device performance of the present invention has still been greatly improved compared to a general TADF device without a phosphorescent photosensitizer. Among them, compared with Comparative Example 3, the maximum emission wavelengths of Examples 5-6 are basically the same as that of Comparative Example 3, the full width at half maximum (FWHM) is basically equivalent to that of Comparative Example 3 and both have a narrow FWHM, but the EQE values are respectively increased by 1.77 times and 1.98 times. Compared with Comparative Example 4, the maximum emission wavelengths of Examples 7-8 are the same as that of Comparative Example 4, the FWHM is basically equivalent to that of Comparative Example 4 and both have a narrow FWHM, but the EQE values are respectively increased by 40.8% and 36.5%. These data further prove that for the organic electroluminescent device of the present invention which contains a polymer in the hole injection layer and the hole transport layer and contains a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound represented by the structure of Formula 1 in the light-emitting layer, compared with a general TADF device without a phosphorescent photosensitizer, it can maintain a narrow FWHM and greatly improve the device efficiency, showing very excellent device performance.

[0394] The light-emitting layer of the organic electroluminescent device of the present invention is prepared by a solution method. Therefore, the organic functional layer between the anode and the light-emitting layer, such as the first organic layer, needs to contain a polymer and cannot only contain small molecules, otherwise the interface / membrane layer of the organic functional layer between the anode and the light-emitting layer may be damaged during the process of preparing the device by the solution method. The organic electroluminescent device of the present invention not only has the advantages of low cost and simple process brought by the solution method, but also can maintain a narrow FWHM and greatly improve the device efficiency compared with a general TADF device without a platinum metal complex as a phosphorescent photosensitizer, showing very excellent device performance and having broad application prospects.

[0395] On the one hand, in the organic electroluminescent device of the present invention, the light-emitting layer containing the first host compound, the second host compound, the platinum metal complex and the thermally activated delayed fluorescence compound is prepared by a solution method, which solves the problem of requiring four evaporation sources when preparing the light-emitting layer by evaporation method, and has advantages such as low cost and simple process. Moreover, in the organic electroluminescent device of the present invention, the organic functional layer (such as the first organic layer) between the anode and the light-emitting layer contains a polymer, so the interface / membrane layer of the organic functional layer will not be damaged during the process of preparing the device by the solution method, fully demonstrating the advantages of using the solution method to prepare the organic electroluminescent device of the present invention. On the other hand, the light-emitting layer of the organic electroluminescent device of the present invention contains the first host compound, the second host compound, the platinum metal complex, and the thermally activated delayed fluorescence compound represented by the structure of Formula 1. By using the method of co-doping the platinum metal complex and the thermally activated delayed fluorescence compound in the host, 100% exciton utilization rate is achieved. Compared with ordinary TADF devices without phosphorescent sensitizers, it can maintain a relatively narrow full width at half maximum and greatly improve the device efficiency, showing very excellent device performance and having broad application prospects.

[0396] It should be understood that the various embodiments described herein are only examples and are not intended to limit the scope of the present invention. Thus, 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 may be replaced with other materials and structures without departing from the spirit of the present invention. It should be understood that the various theories as to why the present invention works are not intended to be limiting.

Claims

1. An organic electroluminescent device, comprising: an anode, a cathode, a light-emitting layer disposed between the anode and the cathode, and a first organic layer disposed between the anode and the light-emitting layer; Among them, the first organic layer contains a polymer; the light-emitting layer is prepared by a solution method, and the light-emitting layer contains a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound; wherein the thermally activated delayed fluorescence compound has a structure represented by Formula 1: wherein, Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from an unsaturated carbocyclic ring having 5-30 carbon atoms or an unsaturated heterocyclic ring having 3-30 carbon atoms; Y1, E1, and E2 are each independently selected from B, N, P, P=O, P=S, As, As=O, As=S, SiR', or GeR'; T1 to T8 are each independently selected from C, CR z or N; T9 and T 10 are each independently selected from C, CR z , CR t or N; L1, L2, L3, L4 are each independently selected from a single bond, O, S, Se, BR, or NR, each occurrence being the same or different. v v or NR v v ; a, b, c, d, and e are each independently selected from 0 or 1; When e is 1, b is 0, and c is 0, T9 and T 10 are each independently selected from CR t or N; R z each occurrence independently represents mono-substitution, multi-substitution or no substitution, which may be the same or different; R t each occurrence is the same or different and is selected from small steric hindrance groups; R v , R z and R' are each, independently upon each occurrence, selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof; R” is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3-20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1-20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3-20 ring atoms, a substituted or unsubstituted aralkyl group having 7-30 carbon atoms, a substituted or unsubstituted alkoxy group having 1-20 carbon atoms, a substituted or unsubstituted aryloxy group having 6-30 carbon atoms, a substituted or unsubstituted alkenyl group having 2-20 carbon atoms, a substituted or unsubstituted alkynyl group having 2-20 carbon atoms, a substituted or unsubstituted aryl group having 6-30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, a substituted or unsubstituted alkylgermyl group having 3-20 carbon atoms, a substituted or unsubstituted arylgermyl group having 6-20 carbon atoms, a substituted or unsubstituted amino group having 0-20 carbon atoms, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphino group, and combinations thereof; Adjacent substituents R t ,R v ,R z ,R', and R" may optionally be joined to form a ring.

2. The organic electroluminescent device according to claim 1, wherein Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from a five-membered unsaturated carbocyclic ring, an aromatic ring having 6-30 carbon atoms, or a heteroaromatic ring having 3-30 carbon atoms; Preferably, Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from a benzene ring, a pyridine ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, an indene ring, a fluorene ring, an indole ring, a carbazole ring, a benzofuran ring, a dibenzofuran ring, a benzosilole ring, a dibenzosilole ring, a benzothiophene ring, a dibenzothiophene ring, a dibenzoselenophene ring, a cyclopentadiene ring, a furan ring, a thiophene ring, or a silole ring; More preferably, Ring A, Ring B, Ring C, Ring D, and Ring E are selected from benzene rings.

3. The organic electroluminescent device according to claim 1, wherein the thermally activated delayed fluorescence compound has a structure represented by Formula 1-1 or Formula 1-2: wherein, a, b, c, and d are each independently selected from 0 or 1; T9 and T 10 are each independently selected from C, CR z or CR t ; When b is 0 and c is 0, T9 and T 10 are each independently selected from CR t ; E1 and E2 are each independently selected from B or N; L1, L2, L3, and L4 are each independently selected from a single bond, O, S, Br v or NR v ; R z Each occurrence independently represents unsubstituted, mono-substituted, or poly-substituted; R t independently and identically or differently selected from small steric hindrance groups each time it appears; R v , R z is the same as or different from each other each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl group, carbonyl group, carboxyl group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphino group, -BR”R”, and combinations thereof; R” is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, a halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; Adjacent substituents R t ,R v ,R z and R” may optionally be linked to form a ring.

4. The organic electroluminescent device according to claim 1 or 3, wherein a is 0, b is 0, c is 0, and d is 0; or a is 1, b is 0, c is 0, and d is 1; or a is 0, b is 1, c is 0, and d is 1.

5. The organic electroluminescent device according to claim 3, wherein each occurrence of L1, L2, L3, and L4 is the same as or different from one another and is independently selected from a single bond, O, BR v or NR v , and each occurrence of R v is the same as or different from one another and is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, and substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms; Preferably, in Formula 1-1, L1, L2, L3, and L4 are each independently selected from a single bond; in Formula 1-2, L1, L2, L3, and L4 are each independently selected from O or NR v , where said R v is each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, and substituted or unsubstituted heteroaryl having 3-30 carbon atoms.

6. The organic electroluminescent device according to claim 1 or 3, wherein said R z is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, and combinations thereof; Preferably, the R z is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, cyano, and combinations thereof.

7. The organic electroluminescent device according to claim 1 or 3, wherein a plurality of Rs are present in the thermally activated delayed fluorescence compound z , and at least one of the plurality of Rs z is selected from the group consisting of: a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, and combinations thereof.

8. The organic electroluminescent device according to claim 1 or 3, wherein said R t is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, unsubstituted alkyl having 1 to 6 carbon atoms, unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, unsubstituted heteroalkyl having 1 to 6 carbon atoms, unsubstituted heterocyclic group having 3 to 6 ring atoms, unsubstituted alkylsilyl having 3 to 6 carbon atoms, unsubstituted amino group having 0 to 6 carbon atoms, phenyl, and combinations thereof; Preferably, said R t is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, unsubstituted alkyl having 1 to 6 carbon atoms, unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, unsubstituted amino having 0 to 6 carbon atoms, and combinations thereof; More preferably, said R t is the same as or different from each other each time it appears and is selected from hydrogen, deuterium or a halogen.

9. The organic electroluminescent device according to claim 1, wherein the thermally activated delayed fluorescence compound is selected from the group consisting of Compound BD1 to Compound BD53: Among them, Optionally, the hydrogen in Compound BD1 to Compound BD53 can be partially or completely substituted by deuterium.

10. The organic electroluminescent device according to claim 1, wherein the platinum metal complex has a structure represented by Formula 2: In Formula 2, Ring F, Ring G, Ring H, and Ring I are each independently selected from an unsaturated carbocyclic ring having 5 to 30 carbon atoms, an unsaturated heterocyclic ring having 1 to 30 carbon atoms, or a combination thereof; f is selected from 0 or 1; A1 - A4 are each independently selected, each time they appear, from a single bond, O, S, Se, (SiR q R q ), y , PR q , NR q , (CR q R q ), y , a substituted or unsubstituted arylene having 6 - 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 - 30 carbon atoms, or a combination thereof; y is each independently selected, each time it appears, from 1, 2, 3, 4 or 5; X1 - X4 are each independently selected from C or N; K1 - K4 are each independently selected from a single bond, O, or S; R n Each occurrence independently represents mono-substitution, multi-substitution or no substitution, which may be the same or different; R q ,R n is the same or different each time it appears and is selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R q , R n may optionally be linked to form a ring; Preferably, the platinum metal complex has a structure represented by Formula 2-1: In Formula 2-1, Ring F, Ring G, and Ring H are each independently selected from an unsaturated carbocyclic ring having 5 to 30 carbon atoms, an unsaturated heterocyclic ring having 3 to 30 carbon atoms, or a combination thereof; Ring I is selected from an unsaturated heterocyclic ring having 1 to 30 carbon atoms; A3 and A4 are each independently selected from a single bond, O, S, Se, (SiR q R q ), y , PR q , NR q , (CR q R q ), y , a substituted or unsubstituted arylene having 6 - 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 - 30 carbon atoms, or a combination thereof; y is the same or different each time it appears and is selected from 1, 2, 3, 4, or 5; K1 - K4 are each independently selected from a single bond, O, or S; X1 - X3 are each independently selected from C or N; R n Each occurrence is the same or different and is represented as mono-substituted, multi-substituted or unsubstituted; R, R q , R n each occurrence of which is the same as or different from one another and is independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R, R q , R n can optionally be linked to form a ring.

11. The organic electroluminescent device according to claim 10, wherein Ring F, Ring G, and Ring H are each independently selected from a five-membered unsaturated carbocyclic ring, an aromatic ring having 6 to 30 carbon atoms, or a heteroaromatic ring having 3 to 30 carbon atoms; Ring I is selected from an unsaturated heterocyclic ring having 3 to 30 carbon atoms; Preferably, the ring F, ring G, and ring H are each independently selected from a five-membered unsaturated carbon ring, an aromatic ring having 6 to 18 carbon atoms, or a heteroaromatic ring having 3 to 18 carbon atoms; the ring I is selected from an unsaturated heterocyclic ring having 3 to 18 carbon atoms; More preferably, the ring F, ring G, and ring H are each independently selected from a benzene ring, a pyridine ring, an indene ring, a fluorene ring, an indole ring, a carbazole ring, a benzofuran ring, a dibenzofuran ring, a benzosilole ring, a dibenzosilole ring, a benzothiophene ring, a dibenzothiophene ring, a dibenzoselenophene ring, a cyclopentadiene ring, a furan ring, a thiophene ring, or a silole ring; the ring I is selected from an imidazolium carbene ring or a benzimidazolium carbene ring.

12. The organic electroluminescent device according to claim 10, wherein the platinum metal complex has a structure represented by one of Formulas 3-1 to 3-18: Wherein, A4 is the same as or different from each occurrence and is selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , a substituted or unsubstituted arylene having 6 - 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 - 30 carbon atoms, or a combination thereof; y is the same as or different from each occurrence and is selected from 1, 2 or 3; U1-U 20 each occurrence being the same as or different from each other and independently selected from CR n or N; R u Each occurrence is the same or different and is represented as mono-substituted, multi-substituted or unsubstituted; R, R N , R q , R u and R n each occurrence is independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R, R N , R q , R u and R n may optionally be linked to form a ring; Preferably, the platinum metal complex has a structure represented by Formula 3-1 or Formula 3-2.

13. The organic electroluminescent device according to claim 12, wherein the R has a structure represented by Formula 4: In Formula 4, The ring M and the ring W are each the same or different each time they appear and are selected from an unsaturated carbon ring having 5 to 30 carbon atoms, an unsaturated heterocyclic ring having 3 to 30 carbon atoms, or a combination thereof; X5 - X8 are each the same or different each time they appear and are selected from C or N; "*" represents the connection position of Formula 4; R m ,R w is the same or different each time it appears and represents mono-substituted, multi-substituted or unsubstituted; R m and R w each occurrence is the same or different and is selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R m , R w can optionally be linked to form a ring; Preferably, at least one R on the ring W in Formula 4 w is selected from the group consisting of: deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof.

14. The organic electroluminescent device according to claim 1, wherein the platinum metal complex has a structure represented by Pt(L a )(L b ), where L a and L b are a first ligand and a second ligand coordinated to the metal Pt, respectively, and the L a is selected from the group consisting of L a 1-1 to L a 1-25 and L a 2-1 to L a 2-6: The said L a 1-1 to L a 1-25 and L a 2-1 to L a In the 2-6 structure, "#" indicates the position connected to L b connection position; The said L b selected from the group consisting of L b 1-1 to L b 1-8 and L b 2-1 to L b 2-22: The said L b 1-1 to L b 1-8 and L b 2-1 to L b In the 2-22 structure Indicates the position connected to "#" in L a ; "t-Bu" in the structure represents tert-butyl, and "i-Pr" represents isopropyl; Preferably, the platinum metal complex is selected from the group consisting of Pt1 to Pt81, and Pt1 to Pt81 have the structure represented by Pt(L a )(L b ), where L a and L b are respectively selected from the structures shown in the following table:

15. The organic electroluminescent device according to claim 1, wherein the first host compound has a structure represented by one of Formulas 5 to 7: In Formula 5, Z1 to Z3 are each the same or different each time they appear and are selected from CR4 or N, and at least one of Z1 to Z3 is N; L is each the same or different each time it appears and is selected from the group consisting of: a single bond, a substituted or unsubstituted arylene having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, and combinations thereof; In Formulas 6 and 7, Z4 is each the same or different each time it appears and is selected from CR4 or N, and at least one Z4 is N; Z is each the same or different each time it appears and is selected from O or S; Each occurrence of R1-R4 is the same as or different from each other and is independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R4 can optionally be joined to form a ring; Preferably, the first host compound has a structure represented by Formula 5-1 or Formula 6-1: In Formula 5-1, R1 and R2 are each independently selected from substituted or unsubstituted heteroaryl having 3-30 carbon atoms; L is selected from a single bond, substituted or unsubstituted arylene having 6-30 carbon atoms, substituted or unsubstituted heteroarylene having 3-30 carbon atoms, or combinations thereof; In Formula 6-1, Z is selected from O or S; Z 41 -Z 48 is the same as or different from each other, each time it appears, selected from CR4, CR4' or N, and Z 41 -Z 48 at least one of which is selected from N and at least one of which is selected from CR4'; Each occurrence of R4’ is the same as or different from each other and is selected from substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, or combinations thereof; R L , each occurrence of R4 is the same as or different from and is independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R4 can optionally be joined to form a ring; More preferably, the first host compound is selected from the group consisting of Compound N-1-1 to Compound N-1-60, Compound N-2-1 to Compound N-2-35, and Compound N-3-1 to Compound N-3-9: Among them, Optionally, the hydrogen in the structures of Compound N-1-1 to Compound N-1-53, Compound N-1-58, Compound N-2-1 to Compound N-2-32, and Compound N-3-1 to Compound N-3-7 can be partially or completely replaced by deuterium.

16. The organic electroluminescent device according to claim 1, wherein the second host compound has a structure represented by Formula 8: In Formula 8, L 11 selected from a single bond, a substituted or unsubstituted arylene having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof; Ar 11 selected from a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, a substituted or unsubstituted amino having 0 to 30 carbon atoms, or a combination thereof; Each occurrence of R6 represents single substitution, multiple substitutions, or no substitution; Each occurrence of R6 is the same as or different from each other and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R6 can optionally be linked to form a ring; Preferably, the second host compound has a structure represented by Formula 8-1 or Formula 8-2: L 11 ,L 12 selected from a single bond, a substituted or unsubstituted arylene having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof; Ar 11 selected from a substituted or unsubstituted aryl having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, a substituted or unsubstituted amino having 0 to 30 carbon atoms, or a combination thereof; Each occurrence of R6 represents mono-substituted, multi-substituted or unsubstituted, the same as or different from each other; Each occurrence of R6 is the same as or different from each other and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R6 can optionally be linked to form a ring; More preferably, the second host compound is selected from the group consisting of Compound P-1 to Compound P-39: Among them, Optionally, the hydrogen in the structures of Compound P-1 to Compound P-23 and Compound P-27 to Compound P-39 can be partially or completely replaced by deuterium.

17. The organic electroluminescent device according to claim 1, wherein the first host compound and the second host compound are host materials, the platinum metal complex is a phosphorescent sensitizer, and the thermally activated delayed fluorescence compound is a luminescent material.

18. The organic electroluminescent device according to claim 1, wherein the proportion of the first host compound and the second host compound in the total weight of the luminescent layer materials is 65% - 98.9%, the proportion of the platinum metal complex in the total weight of the luminescent layer materials is 1% - 30%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer materials is 0.1% - 5%; Preferably, the proportion of the first host compound and the second host compound in the total weight of the luminescent layer materials is 82% - 94.5%, the proportion of the platinum metal complex in the total weight of the luminescent layer materials is 5% - 15%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer materials is 0.5% - 3%; More preferably, the proportion of the first host compound and the second host compound in the total weight of the luminescent layer materials is 86.5% - 91.5%, the proportion of the platinum metal complex in the total weight of the luminescent layer materials is 8% - 12%, and the proportion of the thermally activated delayed fluorescence compound in the total weight of the luminescent layer materials is 0.5% - 1.5%.

19. The organic electroluminescent device according to claim 1, wherein the first organic layer is a hole injection layer or the first organic layer is a hole transport layer.

20. The organic electroluminescent device according to claim 1, wherein the polymer is a polymer having hole transport properties; preferably, the polymer contains a triarylamine structure.

21. A display device comprising the organic electroluminescent device according to any one of claims 1 - 20.

22. An organic light - emitting ink comprising a solvent, a first host compound, a second host compound, a platinum metal complex, and a thermally activated delayed fluorescence compound; wherein the thermally activated delayed fluorescence compound has a structure represented by Formula 1: wherein, Ring A, Ring B, Ring C, Ring D, and Ring E are each independently selected from an unsaturated carbocyclic ring having 5 - 30 carbon atoms or an unsaturated heterocyclic ring having 3 - 30 carbon atoms; Y1, E1, and E2 are each independently selected from B, N, P, P=O, P=S, As, As=O, As=S, SiR', or GeR'; T1 to T8 are each independently selected from C, CR z or N; T9 and T 10 are each independently selected from C, CR z , CR t or N; L1, L2, L3, and L4 are each independently selected from a single bond, O, S, Se, Br v or NR v ; a, b, c, d, and e are each independently selected from 0 or 1; When e is 1, b is 0, and c is 0, T9 and T 10 are each independently selected from CR t or N; R z each occurrence independently represents unsubstituted, mono-substituted, or poly-substituted; R t each occurrence being the same or different and selected from small steric hindrance groups; R v ,R z and R' are each independently selected, each time they appear, from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl, phosphino, -BR”R”, and combinations thereof; R” is the same or different each time it appears and is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1-20 carbon atoms, substituted or unsubstituted heterocyclic group having 3-20 ring atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryloxy having 6-30 carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkynyl having 2-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, substituted or unsubstituted alkylgermyl having 3-20 carbon atoms, substituted or unsubstituted arylgermyl having 6-20 carbon atoms, substituted or unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxyl, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof; Adjacent substituents R t , R v , R z , R', and R" can optionally be joined to form a ring.

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