White-light organic light-emitting device and electronic equipment thereof

Abstract

A white organic electroluminescent device is disclosed. The white organic light-emitting device comprises a first electrode, a second electrode and an organic layer arranged between the first electrode and the second electrode. At least one of the first light-emitting layer, the second light-emitting layer and the third light-emitting layer contains a phosphorescent compound and a delayed fluorescent compound, the phosphorescent material is a sensitizing material, and the delayed fluorescent compound is a light-emitting material with the photoluminescence spectrum peak wavelength smaller than 600 nm; and no charge generation layer is arranged between any two adjacent light-emitting layers. The obtained white light organic light-emitting device can significantly improve the energy transfer efficiency and the exciton utilization efficiency, so that the overall light-emitting efficiency and the current efficiency of the device are improved. The invention also discloses an electronic device comprising the white light organic light-emitting device.

Description

Technical Field

[0001] This invention relates to white organic light-emitting devices. In particular, it relates to a white organic light-emitting device in which a phosphorescent photosensitizer is contained in the light-emitting layer, and an electronic device comprising the same. Background Technology

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

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

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

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

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

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

[0008] OLEDs are self-emissive devices. When a voltage is applied to the device, charges are injected into the organic film from the cathode and holes from the anode. Electrons and holes recombine and then annihilate, producing light. Compared to other flat-panel display technologies such as LCDs, organic light-emitting diodes (OLEDs) have significant advantages, such as high brightness, high luminous efficiency, adjustable color, high color gamut, high saturation, wide viewing angle, low energy consumption, and flexible display. These advantages have extremely broad prospects in the field of full-color displays, making it one of the most influential choices among next-generation display technologies. Currently, the scientific and industrial communities are actively participating in and continuously exploring the field of organic light-emitting diode technology, and have achieved considerable research results in improving the performance of organic light-emitting devices. Among them, white organic light-emitting diodes have become a current research hotspot due to their application potential in full-color displays and high-end lighting.

[0009] The fabrication of high-efficiency white organic light-emitting diodes (OLEDs) has always been a key research focus in this field. Domestic and international research teams have increasingly favored the study of all-fluorescent white organic light-emitting diodes. For example, in 2009, Ma Dongge et al. from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, published a research paper in *Organic Electronics* (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. "Chinese Academy of Sciences Prepares Highly Efficient and Stable All-Fluorescent White OLED." *Rare Earth Information* 11 (2009): 1.), demonstrating how to obtain all-fluorescent white light-emitting devices by doping red, green, and blue organic fluorescent materials into different emitting layers. However, white organic light-emitting diodes fabricated based on ordinary fluorescent materials cannot meet the current application requirements for high efficiency and high performance.

[0010] Therefore, how to obtain white organic electroluminescent devices with better performance, such as higher efficiency, lower voltage and longer lifespan, remains an urgent problem to be solved. Summary of the Invention

[0011] This invention aims to provide a novel white-light organic electroluminescent device to solve at least some of the aforementioned problems. The novel white-light organic electroluminescent device comprises at least three emitting layers, at least one of which contains a phosphorescent compound and a delayed fluorescence compound. The phosphorescent material is a sensitizing material. No charge-generating layer is present between any two adjacent emitting layers. By employing a phosphorescent compound-sensitized delayed fluorescence material technique, the resulting white-light organic electroluminescent device can effectively improve the efficiency of composite white-light devices, thereby achieving superior device performance.

[0012] According to an embodiment of the present invention, a white light organic electroluminescent device is disclosed, comprising: an anode, a cathode, and a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer disposed between the anode and the cathode; wherein at least one of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer contains at least one phosphorescent compound and at least one delayed fluorescence compound, wherein the phosphorescent compound is a sensitizing material, and the delayed fluorescence compound is a light-emitting material with a photoluminescence spectrum peak wavelength of less than 600 nm; no charge generation layer is contained between any two adjacent light-emitting layers of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer.

[0013] According to one embodiment of the present invention, an electronic device is also disclosed, which includes the white organic electroluminescent device described in the foregoing embodiments.

[0014] The novel white organic light-emitting device provided by this invention employs at least three emitting layers, with no charge-generating layer between any two adjacent emitting layers. At least one of the three emitting layers contains a phosphorescent compound as a sensitizing material. By using a phosphorescent compound to sensitize the delayed fluorescence material, the device efficiency of the white organic light-emitting device can be significantly improved, resulting in superior device performance and unexpected unique advantages and broad application prospects. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a typical organic light-emitting device.

[0016] Figure 2 This is a schematic diagram of another typical organic light-emitting device.

[0017] Figure 3 This is a cross-sectional schematic diagram of the analog device 300 involved in an embodiment of the present invention.

[0018] Figures 4-8 These are the EL spectra of single-layer devices D-1, D-2, D-3, D-4, and D-5, respectively. Detailed Implementation

[0019] OLEDs can be manufactured on various substrates, such as glass, plastic, and metal. Figure 1An organic light-emitting device 100 is illustrated schematically and non-limitingly. The figures are not necessarily drawn to scale, and some layer structures may be omitted as needed. Device 100 may include a substrate 101, an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode 190. Device 100 can be fabricated by sequentially depositing the described layers. The properties and functions of each layer, as well as exemplary materials, are described in more detail in columns 6-10 of U.S. Patent 7,279,704B2, the entire contents of which are incorporated herein by reference.

[0020] Each of these layers has numerous examples. For instance, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated herein by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. An example of a host compound is disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated herein by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of cathodes are disclosed in U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entirety. These cathodes comprise composite cathodes having a thin metal layer, such as Mg:Ag, overlaid with a transparent, conductive, sputter-deposited ITO layer. The principles and use of barrier layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are also incorporated herein by reference in their entirety. Examples of implantation layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is also incorporated herein by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is also incorporated herein by reference in its entirety.

[0021] The layered structure described above is provided through non-limiting embodiments. The functionality of an OLED can be achieved by combining the various layers described above, or some layers can be omitted entirely. It may also include other layers not explicitly described. Within each layer, a single material or a mixture of multiple materials can be used to achieve optimal performance. Any functional layer may include several sublayers. For example, a light-emitting layer may have two different light-emitting materials to achieve a desired emission spectrum.

[0022] In one embodiment, an OLED can be described as having an "organic layer" disposed between a cathode and an anode. This organic layer may include one or more layers.

[0023] OLEDs also require an encapsulation layer, such as Figure 2 An organic light-emitting device 200 is shown schematically and non-limitingly, which is related to... Figure 1 The difference lies in the fact that an encapsulation layer 102 may also be included above the cathode 190 to protect against harmful substances from the environment, such as moisture and oxygen. Any material capable of providing encapsulation can be used as the encapsulation layer, such as glass or an organic-inorganic hybrid layer. The encapsulation layer should be placed directly or indirectly on the outside of the OLED device. Multilayer thin-film encapsulation is described in U.S. Patent 7,968,146B2, the entire contents of which are incorporated herein by reference.

[0024] Devices manufactured according to embodiments of the present invention can be incorporated into a variety of consumer products having one or more electronic component modules (or units). Some examples of such consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, head-up displays, fully or partially transparent displays, flexible displays, smartphones, tablet computers, phablets, wearable devices, smartwatches, laptop computers, digital cameras, portable camcorders, viewfinders, microdisplays, 3D displays, vehicle displays, and taillights.

[0025] The materials and structures described in this article can also be used in other organic electronic devices listed above.

[0026] As used herein, "top" means furthest from the substrate, and "bottom" means closest to the substrate. When the first layer is described as being "disposed" on the second layer, the first layer is positioned further from the substrate. Unless it is specified that the first layer "contacts" the second layer, other layers may exist between the first and second layers. For example, even if various organic layers exist between the cathode and anode, the cathode may still be described as being "disposed" on the anode.

[0027] As used herein, “solution-handleable” means capable of being dissolved, dispersed or transported in and / or deposited from a liquid medium in the form of a solution or suspension.

[0028] When a ligand is believed to directly contribute to the photosensitivity of the emitting material, the ligand can be called "photosensitive." When a ligand is believed not to contribute to the photosensitivity of the emitting material, the ligand can be called "auxiliary," but auxiliary ligands can alter the properties of photosensitivity ligands.

[0029] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistical limit through delayed fluorescence. Delayed fluorescence can generally be divided into two types: P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0030] On the other hand, E-type delayed fluorescence does not depend on the collision of two triplet states, but rather on the transition between triplet and singlet excited states. Compounds capable of producing E-type delayed fluorescence need to have a very small singlet-triple gap to facilitate the transition between energy states. Thermal energy can activate the transition from triplet to singlet. This type of delayed fluorescence is also called thermally activated delayed fluorescence (TADF). A significant characteristic of TADF is that the delayed component increases with increasing temperature. If the reverse system crossover (RISC) rate is fast enough to minimize the nonradiative decay from the triplet state, the fraction of singlet excited states that are refilled can reach 75%. The total singlet fraction can be 100%, far exceeding the 25% spin statistics of electrogenerated excitons.

[0031] E-type delayed fluorescence can be observed in excited complex systems or single compounds. Unbound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triple bandgap (ΔE). S-T Organic, nonmetallic donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized as donor-acceptor charge transfer (CT) emission. Spatial separation of the HOMO and LUMO in these donor-acceptor compounds usually produces small ΔE. S-T These states can include CT states. Typically, donor-acceptor luminescent materials are constructed by linking an electron donor moiety (e.g., an amino or carbazole derivative) with an electron acceptor moiety (e.g., an N-containing six-membered aromatic ring).

[0032] The charge generation layer (CGL), also known as the charge generation layer or carrier generation layer, is a functional interface between different light-emitting units in a tandem device (or stacked device) where multiple light-emitting units are stacked between two electrodes. The CGL typically contacts the hole transport region (including but not limited to hole injection layer, hole transport layer, and electron blocking layer) or electron transport region (including but not limited to electron injection layer, electron transport layer, and hole blocking layer) of adjacent light-emitting units. Obviously, the CGL does not directly contact the light-emitting layer. In this paper, in the white organic electroluminescent device of the present invention, there is no CGL between any two of the first, second, and third light-emitting layers.

[0033] The luminescent layer comprises a host material, a sensitizing material, and an acceptor luminescent material. The host material possesses excellent hole or electron mobility, ensuring the effective migration and recombination of holes and electrons within the luminescent layer. Alternatively, the Dexter energy transfer mechanism can be used to transfer absorbed energy to the sensitizer and / or acceptor luminescent material. The sensitizer acts as a bridge for energy transfer, efficiently transferring the energy absorbed by the host material to the acceptor luminescent material. The acceptor luminescent material receives energy from the host or sensitizer and transitions to an excited state, then returns to the ground state through radiative transition (luminescence). The triplet energy is transferred to the TADF acceptor through the phosphorescent sensitizer, and the triplet exciton is converted into a singlet exciton for luminescence through reverse intersystem crossing (RISC). This allows the TADF material to utilize both singlet and triplet excitons simultaneously, achieving an internal quantum efficiency (IQE) close to 100%. Phosphorescent sensitized TADF, through the synergistic mechanism of "efficient triplet energy transfer by the sensitizer and RISC utilization by the TADF material," breaks through the bottlenecks of traditional fluorescent and phosphorescent OLEDs, combining advantages such as high brightness, high efficiency, and low cost, and has become an important direction for next-generation display technology.

[0034] In traditional luminescent material systems, excitons are prone to quenching due to inefficient energy transfer, resulting in low exciton utilization. By optimizing the cascaded energy transfer from the host to the sensitizer to the luminescent acceptor material, energy is transferred in the direction of host => sensitizer => acceptor. This cascaded energy transfer constructs a clear energy transfer path. The percentage of spectral overlap is obtained by integrating the overlap area of ​​the normalized emission spectrum of the sensitizer and the normalized absorption spectrum of the acceptor material, and dividing it by the integrated area of ​​the normalized emission spectrum of the sensitizer. This percentage is used to evaluate... The resonant energy transfer (FRET) efficiency is a key parameter. The greater the overlap between the sensitizer emission spectrum and the acceptor absorption spectrum, the higher the FRET efficiency. An efficient FRET process can significantly shorten the residence time of excitons on the donor material and suppress nonradiative recombination, thereby improving the external quantum efficiency of the device.

[0035] Definition of the term "substituent group"

[0036] Halogens or halides—as used herein—include fluorine, chlorine, bromine, and iodine.

[0037] Alkyl – as used herein, includes straight-chain and branched alkyl groups. An alkyl group can be an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecanyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, and 3-methylpentyl. Among the above, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, and n-hexyl are preferred. Additionally, the alkyl group may optionally be substituted.

[0038] Cycloalkyl – as used herein, comprises cyclic alkyl groups. The cycloalkyl group can be a cycloalkyl group having 3 to 20 carbon atoms, preferably a cycloalkyl group having 4 to 10 carbon atoms. Examples of cycloalkyl groups include cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl, etc. Among the above, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, and 4,4-dimethylcyclohexyl are preferred. Furthermore, the cycloalkyl group may optionally be substituted.

[0039] Heteroalkyl – as used herein, a heteroalkyl group comprises one or more carbon atoms in an alkyl chain that are replaced by heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, selenium, phosphorus, silicon, germanium, and boron atoms. The heteroalkyl group can be a heteroalkyl group having 1 to 20 carbon atoms, preferably a heteroalkyl group having 1 to 10 carbon atoms, and more preferably a heteroalkyl group having 1 to 6 carbon atoms. Examples of heteroalkyl groups include methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermanylmethyl, trimethylgermanylethyl, trimethylgermanylisopropyl, dimethylethylgermanylmethyl, dimethylisopropylgermanylmethyl, tert-butyldimethylgermanylmethyl, triethylgermanylmethyl, triethylgermanylethyl, triisopropylgermanylmethyl, triisopropylgermanylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl, triisopropylsilylethyl. Additionally, heteroalkyl groups may optionally be substituted.

[0040] Alkenyl – as used herein, encompasses straight-chain, branched, and cyclic olefin groups. An alkenyl group can be an alkenyl group containing 2 to 20 carbon atoms, preferably an alkenyl group having 2 to 10 carbon atoms. Examples of alkenyl groups include vinyl, propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, styryl, 2,2-diphenylvinyl, 1,2-diphenylvinyl, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1-phenylallyl, 2-phenylallyl, 3-phenylallyl, 3,3-diphenylallyl, 1,2-dimethylallyl, 1-phenyl-1-butenyl, 3-phenyl-1-butenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl, cycloheptanetrienyl, cyclooctenyl, cyclooctatetraenyl, and norbornyl. In addition, the alkenyl group can be optionally substituted.

[0041] Alkynyl – as used herein, encompasses straight-chain alkynyl groups. An alkynyl group can be one containing 2 to 20 carbon atoms, preferably one having 2 to 10 carbon atoms. Examples of alkynyl groups include ethynyl, propynyl, propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3,3-dimethyl-1-butynyl, 3-ethyl-3-methyl-1-pentynyl, 3,3-diisopropyl-1-pentynyl, phenylethynyl, phenylpropynyl, etc. Among the above, ethynyl, propynyl, propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, and phenylethynyl are preferred. Furthermore, the alkynyl group may be optionally substituted.

[0042] Aryl or aromatic group – as used herein, both non-fused and fused systems are considered. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, fenene, fluorene, pyrene, etc. Perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene, and naphthalene. Examples of non-fused aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methyldiphenyl, 4”-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesitylene, and m-tetraphenyl. Additionally, the aryl group may optionally be substituted.

[0043] Heterocyclic groups or heterocycles – as used herein, consider non-aromatic cyclic groups. Non-aromatic heterocyclic groups include saturated heterocyclic groups having 3-20 ring atoms and unsaturated non-aromatic heterocyclic groups having 3-20 ring atoms, wherein at least one ring atom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron atoms. Preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms, including at least one heteroatom such as nitrogen, oxygen, silicon, or sulfur. Examples of non-aromatic heterocyclic groups include ethylene oxide, oxetane, tetrahydrofuranyl, tetrahydropyranyl, dioxopentacyclic, dioxahexacyclic, acridineyl, dihydropyrroleyl, tetrahydropyrroleyl, piperidinyl, oxazolidinyl, morpholinyl, piperazineyl, oxetane-heptanetrienyl, thioheptanetrienyl, azirane-heptanetrienyl, and tetrahydrothiorroleyl. In addition, the heterocyclic group can be optionally substituted.

[0044] Heteroaryl – as used herein – can be a non-fused or fused heteroaryl group comprising 1 to 5 heteroatoms, wherein at least one heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron. Isoaryl also refers to heteroaryl. Heteroaryl can be a heteroaryl having 3 to 30 carbon atoms, preferably a heteroaryl having 3 to 20 carbon atoms, and more preferably a heteroaryl having 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolecarbazole, pyridineindole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxtriazole, dioxazole, thiadiazol, pyridine, pyrazine, pyrazine, triazine, oxazine, oxthiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzoisoxazole, benzothiazole, quinoline, isoquinoline Phosphine, cyclophosphine, quinazoline, quinoxaline, naphthidine, phthalazine, pteridine, xanthan, acridine, phenazine, phenothiazine, benzofuranopyridine, furanodipyridine, benzothiophenopyridine, thiophenodipyridine, benzoselenophenopyridine, selenobenzodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborane, 1,3-azaborane, 1,4-azaborane, boronazole and its aza analogues. Additionally, the heteroaryl group may optionally be substituted.

[0045] Alkoxy groups—as used herein—are represented by -O-alkyl, -O-cycloalkyl, -O-heteroalkyl, or -O-heterocyclic groups. Examples and preferred examples of alkyl, cycloalkyl, heteroalkyl, and heterocyclic groups are the same as described above. An alkoxy group can be an alkoxy group having 1 to 20 carbon atoms, preferably an alkoxy group having 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, cyclopropyloxy, cyclobutyloxy, cyclopentoxy, cyclohexyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy, and ethoxymethyloxy. Additionally, alkoxy groups may optionally be substituted.

[0046] Aryloxy group – as used herein, is represented by -O-aryl or -O-heteroaryl. Examples and preferred examples of aryl and heteroaryl groups are the same as described above. The aryloxy group can be an aryloxy group having 6 to 30 carbon atoms, preferably an aryloxy group having 6 to 20 carbon atoms. Examples of aryloxy groups include phenoxy and biphenyloxy groups. Additionally, the aryloxy group may optionally be substituted.

[0047] Arylalkyl – as used herein, encompasses aryl-substituted alkyl groups. An arylalkyl group can be an arylalkyl group having 7 to 30 carbon atoms, preferably an arylalkyl group having 7 to 20 carbon atoms, and more preferably an arylalkyl group having 7 to 13 carbon atoms. Examples of arylalkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl tert-butyl, α-naphthylmethyl, 1-α-naphthyl-ethyl, 2-α-naphthylethyl, 1-α-naphthylisopropyl, 2-α-naphthylisopropyl, β-naphthylmethyl, 1-β-naphthyl-ethyl, 2-β-naphthyl-ethyl, 1-β-naphthylisopropyl, 2-β-naphthylisopropyl, p-methylbenzyl, m-methylbenzyl The compounds include alkyl groups, such as o-methylbenzyl, p-chlorobenzyl, m-chlorobenzyl, o-chlorobenzyl, p-bromobenzyl, m-bromobenzyl, o-bromobenzyl, p-iodobenzyl, m-iodobenzyl, o-iodobenzyl, p-hydroxybenzyl, m-hydroxybenzyl, o-hydroxybenzyl, p-aminobenzyl, m-aminobenzyl, o-aminobenzyl, p-nitrobenzyl, m-nitrobenzyl, o-nitrobenzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-hydroxy-2-phenylisopropyl, and 1-chloro-2-phenylisopropyl. Among the above, benzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, and 2-phenylisopropyl are preferred. Additionally, the alkyl group may optionally be substituted.

[0048] Alkylsilyl – as used herein, encompasses alkyl-substituted silyl groups. The alkylsilyl group can be an alkylsilyl group having 3 to 20 carbon atoms, preferably an alkylsilyl group having 3 to 10 carbon atoms. Examples of alkylsilyl groups include trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tritert-butylsilyl, triisobutylsilyl, dimethyltert-butylsilyl, and methylditert-butylsilyl. Furthermore, the alkylsilyl group may optionally be substituted.

[0049] Arylsilane – as used herein, encompasses at least one aryl-substituted silane group. The arylsilane can be an arylsilane having 6 to 30 carbon atoms, preferably an arylsilane having 8 to 20 carbon atoms. Examples of arylsilanes include triphenylsilyl, phenyldiphenylsilyl, diphenylbiphenylsilyl, phenyldiethylsilyl, diphenylethylsilyl, phenyldimethylsilyl, diphenylmethylsilyl, phenyldiisopropylsilyl, diphenylisopropylsilyl, diphenylbutylsilyl, diphenylisobutylsilyl, and diphenyltert-butylsilyl. Additionally, the arylsilane may optionally be substituted.

[0050] Alkylgermanium group – as used herein, encompasses alkyl-substituted germanium groups. The alkylgermanium group can be an alkylgermanium group having 3 to 20 carbon atoms, preferably an alkylgermanium group having 3 to 10 carbon atoms. Examples of alkylgermanium groups include trimethylgermanium, triethylgermanium, methyldiethylgermanium, ethyldimethylgermanium, tripropylgermanium, tributylgermanium, triisopropylgermanium, methyldiisopropylgermanium, dimethylisopropylgermanium, tritert-butylgermanium, triisobutylgermanium, dimethyltert-butylgermanium, and methylditert-butylgermanium. Furthermore, the alkylgermanium group may optionally be substituted.

[0051] Arylgermanium – as used herein, encompasses a germanium group substituted with at least one aryl or heteroaryl group. The arylgermanium group can be an arylgermanium group having 6 to 30 carbon atoms, preferably an arylgermanium group having 8 to 20 carbon atoms. Examples of arylgermanium groups include triphenylgermanium, phenyldiphenylgermanium, diphenylbiphenylgermanium, phenyldiethylgermanium, diphenylethylgermanium, phenyldimethylgermanium, diphenylmethylgermanium, phenyldiisopropylgermanium, diphenylisopropylgermanium, diphenylbutylgermanium, diphenylisobutylgermanium, and diphenyltert-butylgermanium. Additionally, the arylgermanium group may optionally be substituted.

[0052] The term "aza" in azadibenzofuran, azadibenzothiophene, etc., refers to the substitution of one or more CH groups in the corresponding aromatic segment by a nitrogen atom. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline, and other analogs having two or more nitrogen atoms in the ring system. Other nitrogen analogs of the aforementioned aza derivatives will readily conceive of those skilled in the art, and all such analogs are identified as being included in the terminology used herein.

[0053] In this disclosure, unless otherwise defined, the term "substituted alkyl," "substituted cycloalkyl," "substituted heteroalkyl," "substituted heterocyclic," "substituted aralkyl," "substituted alkoxy," "substituted aryloxy," "substituted alkenyl," "substituted alkynyl," "substituted aryl," "substituted heteroaryl," "substituted alkylsilyl," "substituted arylsilyl," "substituted alkylgermanium," "substituted arylgermanium," "substituted amino," "substituted acyl," "substituted carbonyl," and "substituted carboxylic acid" are used interchangeably. Substituted ester group, substituted sulfinyl group, substituted sulfonyl group, substituted phosphinyl group, refers to any one of the following groups: alkyl, cycloalkyl, heteroalkyl, heterocyclic, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermanium, arylgermanium, amino, acyl, carbonyl, carboxylic acid, ester group, sulfinyl, sulfonyl, and phosphinyl. One or more groups can be selected from deuterium, halogen, unsubstituted alkyl groups having 1-20 carbon atoms, and unsubstituted alkyl groups having... Cycloalkyl groups with 3-20 carbon atoms, unsubstituted heteroalkyl groups with 1-20 carbon atoms, unsubstituted heterocyclic groups with 3-20 carbon atoms, unsubstituted aralkyl groups with 7-30 carbon atoms, unsubstituted alkoxy groups with 1-20 carbon atoms, unsubstituted aryloxy groups with 6-30 carbon atoms, unsubstituted alkenyl groups with 2-20 carbon atoms, unsubstituted alkynyl groups with 2-20 carbon atoms, and unsubstituted aryl groups with 6-30 carbon atoms. Unsubstituted heteroaryl groups having 3-30 carbon atoms, unsubstituted alkylsilyl groups having 3-20 carbon atoms, unsubstituted arylsilyl groups having 6-20 carbon atoms, unsubstituted alkylgermanium groups having 3-20 carbon atoms, unsubstituted arylgermanium groups having 6-20 carbon atoms, and unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphine, and combinations thereof having 0-20 carbon atoms.

[0054] It should be understood that when a molecular segment is described as a substituent or otherwise attached to another part, its name may be written according to whether it is a segment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or attaching segments are considered equivalent.

[0055] In the compounds mentioned in this disclosure, hydrogen atoms can be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen can also be replaced by their other stable isotopes. Substitution with other stable isotopes in the compounds is likely preferred due to their ability to enhance device efficiency and stability.

[0056] In the compounds mentioned in this disclosure, polysubstituted means including disubstituted, up to the maximum range of available substitutions. When a substituent in a compound mentioned in this disclosure represents polysubstituted (including disubstituted, trisubstituted, tetrasubstituted, etc.), it means that the substituent can be present at multiple available substitution positions on its linkage structure. The substituent present at multiple available substitution positions can be the same structure or different structures.

[0057] In the compounds mentioned in this disclosure, unless explicitly specified, for example, that adjacent substituents can optionally connect to form a ring, adjacent substituents in the compounds cannot connect to form a ring. In the compounds mentioned in this disclosure, the optional connection of adjacent substituents to form a ring includes both cases where adjacent substituents can connect to form a ring and cases where adjacent substituents do not connect to form a ring. When adjacent substituents can optionally connect to form a ring, the formed ring can be a monocyclic or polycyclic ring (including spirocyclic, bridged, fused rings, etc.), as well as an alicyclic, heterocyclic, aromatic, or heteroaromatic ring. In this context, adjacent substituents can refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to carbon atoms further away. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0058] The statement that adjacent substituents can optionally connect to form a ring is also intended to be understood as referring to two substituents bonded to the same carbon atom connecting to each other via chemical bonds to form a ring, as exemplified by the following formula:

[0059]

[0060] The statement that adjacent substituents can optionally link to form a ring is also intended to be understood as referring to two substituents bonded to carbon atoms directly bonded to each other forming a ring through chemical bonds, as exemplified by the following formula:

[0061]

[0062] The statement that adjacent substituents can optionally connect to form a ring is also intended to be understood as referring to two substituents bonded to a further distant carbon atom connecting to each other by chemical bonds to form a ring, which can be exemplified by the following formula:

[0063]

[0064] Furthermore, the statement that adjacent substituents can optionally connect to form a ring is also intended to mean that, in the case where one of the two adjacent substituents represents hydrogen, the second substituent bonds to the position where the hydrogen atom is bonded, thereby forming a ring. This is illustrated by the following example:

[0065]

[0066] According to an embodiment of the present invention, a white light organic electroluminescent device is disclosed, comprising: an anode, a cathode, and a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer disposed between the anode and the cathode; wherein at least one of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer comprises at least one phosphorescent compound and at least one delayed fluorescence compound, wherein the phosphorescent material is a sensitizing material, and the delayed fluorescence compound is a light-emitting material with a photoluminescence spectrum peak wavelength of less than 600 nm; no charge generation layer is contained between any two adjacent light-emitting layers of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer.

[0067] According to an embodiment of the present invention, in the white light organic electroluminescent device, at least one of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer contains at least one phosphorescent compound and at least one delayed fluorescence compound, wherein the phosphorescent material is a sensitizing material, and the delayed fluorescence compound is a light-emitting material with a photoluminescence spectrum peak wavelength of less than 500 nm.

[0068] According to one embodiment of the present invention, in the white organic electroluminescent device, the phosphorescent material is a sensitizing material and can transfer energy to the delayed fluorescence compound.

[0069] According to one embodiment of the present invention, the delayed fluorescence compound is a TADF compound.

[0070] According to one embodiment of the present invention, the white organic electroluminescent device includes only one hole transport region and one electron transport region.

[0071] According to one embodiment of the present invention, the first light-emitting layer comprises a sensitizing material S1 and a light-emitting material A1.

[0072] According to one embodiment of the present invention, the peak wavelength of the luminescent material A1 in the photoluminescence spectrum is 400-500 nm, the sensitizing material S1 is a phosphorescent material, and the luminescent material A1 is a TADF compound.

[0073] According to one embodiment of the present invention, the first light-emitting layer further comprises a host compound H1.

[0074] According to one embodiment of the present invention, the second light-emitting layer comprises a light-emitting material A2 and a host compound H2.

[0075] According to one embodiment of the present invention, the peak wavelength of the luminescent material A2 in the photoluminescence spectrum is 500-600 nm.

[0076] According to one embodiment of the present invention, the luminescent material A2 is selected from fluorescent compounds or phosphorescent compounds, wherein the fluorescent compound is a TADF compound.

[0077] According to one embodiment of the present invention, the third light-emitting layer comprises light-emitting material A3 and host compound H3.

[0078] According to one embodiment of the present invention, the peak wavelength of the luminescent material A3 in the photoluminescence spectrum is 600-700 nm.

[0079] According to one embodiment of the present invention, the luminescent material A3 is selected from fluorescent compounds or phosphorescent compounds, wherein the fluorescent compound is a TADF compound.

[0080] According to one embodiment of the present invention, the second light-emitting layer comprises a sensitizing material S4 and a light-emitting material A4.

[0081] According to one embodiment of the present invention, the peak wavelength of the luminescent material A4 in the photoluminescence spectrum is 500-600 nm.

[0082] According to one embodiment of the present invention, the sensitized material S4 is a phosphorescent compound, and the luminescent material A4 is a TADF compound.

[0083] According to one embodiment of the present invention, the second light-emitting layer further comprises the host compound H4.

[0084] According to one embodiment of the present invention, the third light-emitting layer comprises a sensitizing material S5 and a light-emitting material A5, wherein the sensitizing material S5 is a phosphorescent compound and the light-emitting material A5 is a TADF compound.

[0085] According to one embodiment of the present invention, the third light-emitting layer further comprises the host compound H5.

[0086] According to one embodiment of the present invention, the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer between the anode and the cathode can be arbitrarily stacked between the anode and the cathode.

[0087] According to one embodiment of the present invention, a second light-emitting layer, a first light-emitting layer, and a third light-emitting layer are arranged sequentially from the anode to the cathode. In this embodiment, adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0088] According to one embodiment of the present invention, a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer are arranged sequentially from the anode to the cathode. In this embodiment, adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0089] According to one embodiment of the present invention, a third light-emitting layer, a first light-emitting layer, and a second light-emitting layer are arranged sequentially from the anode to the cathode. In this embodiment, adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0090] According to one embodiment of the present invention, a second light-emitting layer, a first light-emitting layer, a third light-emitting layer, and a first light-emitting layer are arranged sequentially from the anode to the cathode, wherein the two first light-emitting layers are the same or different. In this embodiment, two adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0091] According to one embodiment of the present invention, a first light-emitting layer, a third light-emitting layer, a first light-emitting layer, and a second light-emitting layer are arranged sequentially from the anode to the cathode, wherein the two first light-emitting layers may be the same or different. In this embodiment, two adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0092] According to one embodiment of the present invention, a third light-emitting layer, a first light-emitting layer, a second light-emitting layer, and another first light-emitting layer are arranged sequentially from the anode to the cathode, wherein the two first light-emitting layers are the same or different. In this embodiment, two adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0093] According to one embodiment of the present invention, a second light-emitting layer, a third light-emitting layer, another second light-emitting layer, and a first light-emitting layer are arranged sequentially from the anode to the cathode, wherein the two second light-emitting layers may be the same or different. In this embodiment, adjacent light-emitting layers are in direct contact or separated by at least one organic layer.

[0094] According to one embodiment of the present invention, the triplet energy level of the sensitizing material S1 is T1(S1), the triplet energy level of the luminescent material A1 is T1(A1), and the triplet energy level of the host compound H1 is T1(H1), where T1(H1) > T1(S1) > T1(A1).

[0095] According to one embodiment of the present invention, the triplet energy level of the sensitizing material S4 is T1(S4), the triplet energy level of the luminescent material A4 is T1(A4), and the triplet energy level of the host compound H4 is T1(H4), where T1(H4) > T1(S4) > T1(A4).

[0096] According to one embodiment of the present invention, the triplet energy level of the sensitizing material S5 is T1(S5), the triplet energy level of the luminescent material A5 is T1(A5), and the triplet energy level of the host compound H5 is T1(H5), where T1(H5) > T1(S5) > T1(A5).

[0097] According to one embodiment of the present invention, the singlet energy level of the luminescent material A1 is S1(A1), the singlet energy level of the luminescent material A4 is S1(A4), and the singlet energy level of the luminescent material A5 is S1(A5).

[0098] According to one embodiment of the present invention, the S1(A1)-T1(A1) of the luminescent material A1 is ≤300meV.

[0099] According to one embodiment of the present invention, the S1(A1)-T1(A1) of the luminescent material A1 is ≤200meV.

[0100] According to one embodiment of the present invention, the S1(A1)-T1(A1) of the luminescent material A1 is ≤100meV.

[0101] According to one embodiment of the present invention, the S1(A4)-T1(A4) of the luminescent material A4 is ≤300meV.

[0102] According to one embodiment of the present invention, the S1(A4)-T1(A4) of the luminescent material A4 is ≤200meV.

[0103] According to one embodiment of the present invention, the S1(A4)-T1(A4) of the luminescent material A4 is ≤100meV.

[0104] According to one embodiment of the present invention, the S1(A5)-T1(A5) of the luminescent material A5 is ≤300meV.

[0105] According to one embodiment of the present invention, the S1(A5)-T1(A5) of the luminescent material A5 is ≤200meV.

[0106] According to one embodiment of the present invention, the S1(A5)-T1(A5) of the luminescent material A5 is ≤100meV.

[0107] According to one embodiment of the present invention, the highest occupied orbital energy level of the sensitizing material S1 is HOMO(S1), the highest molecular occupied orbital energy level of the luminescent material A1 is HOMO(A1), and HOMO(S1) > HOMO(A1).

[0108] According to one embodiment of the present invention, the highest occupied orbital energy level of the sensitizing material S4 is HOMO(S4), the highest molecular occupied orbital energy level of the luminescent material A4 is HOMO(A4), and HOMO(S4) > HOMO(A4).

[0109] According to one embodiment of the present invention, the highest occupied orbital energy level of the sensitizing material S5 is HOMO(S5), the highest molecular occupied orbital energy level of the luminescent material A5 is HOMO(A5), and HOMO(S5) > HOMO(A5).

[0110] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S1 and the normalized absorption spectrum of the luminescent material A1 is greater than or equal to 3% of the integral area of ​​the normalized photoluminescence spectrum of compound S1.

[0111] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S1 and the normalized absorption spectrum of the luminescent material A1 is greater than or equal to 10% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S1.

[0112] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S1 and the normalized absorption spectrum of the luminescent material A1 is greater than or equal to 20% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S1.

[0113] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S1 and the normalized absorption spectrum of the luminescent material A1 is greater than or equal to 30% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S1.

[0114] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S4 and the normalized absorption spectrum of the luminescent material A4 is greater than or equal to 3% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S4.

[0115] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S4 and the normalized absorption spectrum of the luminescent material A4 is greater than or equal to 10% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S4.

[0116] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S4 and the normalized absorption spectrum of the luminescent material A4 is greater than or equal to 20% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S4.

[0117] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S4 and the normalized absorption spectrum of the luminescent material A4 is greater than or equal to 30% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S4.

[0118] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S5 and the normalized absorption spectrum of the luminescent material A5 is greater than or equal to 3% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S5.

[0119] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S5 and the normalized absorption spectrum of the luminescent material A5 is greater than or equal to 10% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S5.

[0120] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S5 and the normalized absorption spectrum of the luminescent material A5 is greater than or equal to 20% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S5.

[0121] According to one embodiment of the present invention, the overlap area of ​​the normalized photoluminescence spectrum of the sensitizing material S5 and the normalized absorption spectrum of the luminescent material A5 is greater than or equal to 30% of the integral area of ​​the normalized photoluminescence spectrum of the sensitizing material S5.

[0122] According to one embodiment of the present invention, the luminescent material A1 has a doping concentration of X1 in the first luminescent layer, the luminescent material A4 has a doping concentration of X4 in the second luminescent layer, and the luminescent material A5 has a doping concentration of X5 in the third luminescent layer, wherein X1, X4 and X5 satisfy the following: 0% < X1 ≤ 6%, 0% < X4 ≤ 6%, and 0% < X5 ≤ 6%.

[0123] According to one embodiment of the present invention, X1, X4 and X5 satisfy the following: 0.5% ≤ X1 ≤ 1.5%, 0.5% ≤ X4 ≤ 1.5%, and 0.5% ≤ X5 ≤ 1.5%.

[0124] According to one embodiment of the present invention, the first light-emitting layer further comprises the host compound H6.

[0125] According to one embodiment of the present invention, one host compound in the first luminescent layer is a P-type host compound, and the other host compound is an N-type host compound, wherein host compound H1 and host compound H6 form an excitocomplex.

[0126] According to one embodiment of the present invention, the second light-emitting layer further comprises the host compound H7.

[0127] According to one embodiment of the present invention, one host compound in the second luminescent layer is a P-type host compound and the other host compound is an N-type host compound, and host compound H2 and host compound H7 form an excitocomplex.

[0128] According to one embodiment of the present invention, in the second luminescent layer, one host compound is a P-type host compound and the other host compound is an N-type host compound, and host compound H4 and host compound H7 form an excitocomplex.

[0129] According to one embodiment of the present invention, the third light-emitting layer further comprises the host compound H8.

[0130] According to one embodiment of the present invention, one host compound in the third luminescent layer is a P-type host compound and the other host compound is an N-type host compound, and host compound H3 and host compound H8 form an excitocomplex.

[0131] According to one embodiment of the present invention, one host compound in the third luminescent layer is a P-type host compound and the other host compound is an N-type host compound, and host compound H5 and host compound H8 form an excitocomplex.

[0132] According to one embodiment of the present invention, the first light-emitting layer is in direct contact with the second light-emitting layer.

[0133] According to one embodiment of the present invention, the first light-emitting layer and the second light-emitting layer are separated by an organic layer 1, wherein the two sides of the organic layer 1 are in direct contact with the first light-emitting layer and the second light-emitting layer, respectively.

[0134] According to one embodiment of the present invention, the HOMO energy level of the compound in the organic layer 1 is between the HOMO energy level of the host compound in the first luminescent layer and the HOMO energy level of the host compound in the second luminescent layer.

[0135] According to one embodiment of the present invention, the second light-emitting layer is in direct contact with the third light-emitting layer.

[0136] According to one embodiment of the present invention, the second light-emitting layer and the third light-emitting layer are separated by an organic layer 2, wherein the two sides of the organic layer 2 are in direct contact with the second light-emitting layer and the third light-emitting layer, respectively.

[0137] According to one embodiment of the present invention, the HOMO energy level of the compound in the organic layer 2 is between the HOMO energy level of the host compound in the second luminescent layer and the HOMO energy level of the host compound in the third luminescent layer.

[0138] According to one embodiment of the present invention, the first light-emitting layer is in direct contact with the third light-emitting layer.

[0139] According to one embodiment of the present invention, the first light-emitting layer and the third light-emitting layer are separated by an organic layer 3, wherein the organic layer 3 is in direct contact with the first light-emitting layer and the third light-emitting layer on both sides.

[0140] According to one embodiment of the present invention, the HOMO energy level of the compound in the organic layer 3 is between the HOMO energy level of the host compound in the first luminescent layer and the HOMO energy level of the host compound in the third luminescent layer.

[0141] According to one embodiment of the present invention, the compounds contained in organic layer 1, organic layer 2 or organic layer 3 are P-type host compounds and / or N-type host compounds.

[0142] According to one embodiment of the present invention, the compound contained in organic layer 1, organic layer 2 or organic layer 3 is any compound in the electron blocking layer.

[0143] According to one embodiment of the present invention, the compound contained in the organic layer 1, organic layer 2 or organic layer 3 is any compound in the hole blocking layer.

[0144] According to one embodiment of the present invention, the phosphorescent compound is a metal complex having M(L) a ) m (L b ) n (L c ) q The general formula;

[0145] M is selected from metals with a relative atomic mass greater than 40;

[0146] ligand L a L b and L c The first ligand, second ligand, and third ligand, respectively, are coordinated with the metal M, and ligand L is... a L b and L c They can be the same or different;

[0147] ligand L a L b and L c They can be selectively linked to form multidentate ligands;

[0148] m is 1, 2, or 3; n is 0, 1, or 2; q is 0, 1, or 2; the sum of m, n, and q equals the oxidation state of metal M; when m is greater than or equal to 2, multiple L a They can be the same or different; when n is 2, the two Lsb They can be the same or different; when q is 2, the two Ls c They can be the same or different;

[0149] ligand L a It has the structure shown in Equation 1:

[0150]

[0151] When ring F and ring G appear, they are selected, either in the same or different, from unsaturated carbon rings having 5-30 carbon atoms, unsaturated heterocycles having 1-30 carbon atoms, or combinations thereof.

[0152] X1 and X2 are selected from C or N each time they appear, either in the same or different ways.

[0153] K1 and K2 are each independently selected from a single bond, O or S;

[0154] A1 is selected from single bond, O, S, Se, (SiRqRq)y, PRq, NRq, (CRqRq)y, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, or combinations thereof; y is selected from 1, 2, 3, 4 or 5 each time it appears;

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

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

[0157] Adjacent substituent R f R g and R q They can be arbitrarily connected to form a ring.

[0158] In this paper, "adjacent substituent R" f R g and R q "Can be optionally linked to form a ring" is intended to indicate that adjacent substituent groups therein, for example, two substituents R f Between the two substituents R g Between the two substituents R q Between, and substituent R f and R g Between, and substituent R f and R q Between, and substituent R g and R q Between these substituents, any one or more of these substituent groups can connect to form a ring. Obviously, these substituents can also not connect to form a ring.

[0159] According to one embodiment of the present invention, the metal M is selected from the group consisting of Cu, Ag, Au, Ru, Rh, Pd, Os, Ir and Pt each time it appears.

[0160] According to one embodiment of the present invention, the metal M is selected from Pt or Ir each time it appears, either the same or different.

[0161] According to one embodiment of the present invention, the phosphorescent compound has a structure represented by any one of formulas 5-1 to 5-24:

[0162]

[0163]

[0164]

[0165] In this case, A2 is selected from single bonds, O, S, Se, (SiR) each time it appears, either the same or different. q R q ) y PR q NR q , substituted or unsubstituted arylene groups having 6-30 carbon atoms, substituted or unsubstituted heteroarylene groups having 3-30 carbon atoms, or combinations thereof; y is selected from 1, 2 or 3 each time it appears, either identically or differently.

[0166] U1-U 20 Each time it appears, it is selected from CR in the same or different ways. n Or N;

[0167] Each time ring F3 appears, it is selected from unsaturated carbon rings having 5-30 carbon atoms, unsaturated heterocycles having 3-30 carbon atoms, or combinations thereof;

[0168] Q is selected from O, S, or Se each time it appears, either the same or different.

[0169] Each time m appears, it is selected from 0, 1, 2, or 3, either the same or different.

[0170] R u R f3 Each occurrence being the same or different indicates monosubstitution, polysubstitution, or no substitution;

[0171] R, R N R q R u R n R f3 R a R b and R cEach time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0172] Adjacent substituents R, R N R q R u R n and R f3 They can be arbitrarily connected to form a ring.

[0173] In this paper, "adjacent substituents R, R N R q R u R n and R f3 "Can be optionally linked to form a ring" is intended to indicate that adjacent substituent groups therein, for example, between two substituents R, two substituents R N Between the two substituents R q Between the two substituents R q Between the two substituents R u Between the two substituents R n Between the two substituents R f3 Between, and substituents R and R N Between, and substituents R and R q Between these substituents, any one or more of these substituent groups can connect to form a ring. Obviously, these substituents can also not connect to form a ring.

[0174] According to one embodiment of the present invention, the phosphorescent compound may be selected from the group consisting of compounds BD2 to BD9, BD11 to BD18, RD1 to RD220, GD1 to GD46, and GD50 to GD177.

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193] According to one embodiment of the present invention, the phosphorescent compound has Pt(L) a (L) b The structure is represented by ) where L a and L b These are the first and second ligands that coordinate with metallic Pt, respectively, and the L a Choose freely L a 1-1 to L a 1-25 and L a 2-1 to La Groups consisting of 2-10:

[0194]

[0195]

[0196]

[0197] The L a 1-1 to L a 1-25 and L a 2-1 to L a In the structure 2-10, "#" indicates a relationship with L. b The location of the connection; the L b Choose freely L b 1-1 to L b 1-8 and L b 2-1 to L b Groups consisting of 2-24:

[0198]

[0199]

[0200] The L b 1-1 to L b 1-8 and L b 2-1 to L b In the structure 2-24, the "#" indicates a relationship with L. b The location of the connection.

[0201] According to one embodiment of the present invention, the phosphorescent compound is selected from the group consisting of Pt1 to Pt96, wherein Pt1 to Pt96 has Pt(L) a (L) b The structure represented by ) and the L a and the L b These correspond to the structures shown in the table below:

[0202]

[0203]

[0204] According to one embodiment of the present invention, the TADF compound has a structure represented by Formula 2:

[0205]

[0206] Among them, ring A, ring B and ring C are each independently selected from five-membered unsaturated carbon rings, aromatic rings with 6-30 carbon atoms, heteroaromatic rings with 3-30 carbon atoms, or combinations thereof;

[0207] Each time Y appears, it is independently selected from B and CR. z SiR z GeR z N, P or P = O;

[0208] E1 and E2 are each selected independently from a single bond each time they appear, BR z CR z R z SiR z R z GeR z R z NR z PR z P = O(R) z ), O, S, S=O, Se or Se=O;

[0209] R a1 R b1 R c1 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0210] R a1 R b1 R c1 R z Each occurrence is selected from the group consisting of, either identically or differently, of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and so on. The following are substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium alkyl groups having 6-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, BR'R', acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphin, and combinations thereof.

[0211] R', each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms;

[0212] Adjacent substituents Ra1, Rb1, Rc1, Rz, and R' can optionally be linked to form a ring.

[0213] In this document, the phrase "adjacent substituents Ra1, Rb1, Rc1, Rz, R' can optionally connect to form a ring" is intended to indicate that any one or more of the following substituent groups can connect to form a ring: between two substituents Ra1, between two substituents Rb1, between two substituents Rc1, between two substituents Rz, between two substituents R', between substituents Ra1 and Rb1, between substituents Ra1 and Rc1, between substituents Ra1 and Rz, and between substituents Ra1 and R'. It is also apparent that these substituents may not connect to form a ring.

[0214] According to one embodiment of the present invention, the TADF compound has a structure represented by any one of formulas 2-1 to 2-8:

[0215]

[0216]

[0217] In Formulas 2-1 to 2-8, rings A, B, C, D, E, and H are each independently selected from five-membered unsaturated carbon rings, aromatic rings having 6-30 carbon atoms, heteroaromatic rings having 3-30 carbon atoms, or combinations thereof.

[0218] Each of E1 to E4 is independently selected from a single key, BR z CR z R z SiRz R z GeR z R z NR z PR z P = O(R) z ), O, S, S=O, Se or Se=O;

[0219] R a1 R b1 R c1 R d1 R e1 R h1 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0220] R a1 R b1 R c1 R d1 R e1 R h1 R z Each occurrence is selected from the group consisting of, either identically or differently, of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and so on. The following are substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium alkyl groups having 6-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, BR'R', acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphin, and combinations thereof.

[0221] R', each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms;

[0222] Adjacent substituents Ra1, Rb1, Rc1, Rd1, Re1, Rh1, Rz, and R' can optionally be linked to form a ring.

[0223] In this document, the phrase "adjacent substituents Ra1, Rb1, Rc1, Rd1, Re1, Rh1, Rz, R' can optionally connect to form a ring" is intended to indicate that any one or more of these adjacent substituent groups, such as between two substituents Ra1, between two substituents Rb1, between two substituents Rc1, between two substituents Rd1, between two substituents Re1, between two substituents Rh1, between two substituents Rz, between two substituents R', between substituents Ra1 and Rb1, between substituents Ra1 and Rc1, between substituents Ra1 and Rz, between substituents Ra1 and Rd1, between substituents Ra1 and Re1, between substituents Ra1 and Re1, between substituents Ra1 and Rh1, between substituents Ra1 and Rz, and between substituents Ra1 and R', can connect to form a ring. It is also apparent that these substituents can also remain unconnected to form a ring.

[0224] According to one embodiment of the present invention, the TADF compound is selected from the group consisting of compounds BN-BD-1 to BN-BD-53 and BD-1 to BD-265:

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241] Optionally, the hydrogen in compounds BN-BD-1 to BN-BD-53 and BD-1 to BD-265 may be partially or completely replaced by deuterium.

[0242] According to one embodiment of the present invention, the host compound comprises a first host compound, the first host compound being an N-type host compound having a structure represented by any one of Formulas 6 to 8:

[0243]

[0244] In Equation 6, Z4 is selected from CR each time it appears, either the same or different. 10 Or N, and at least one of Z4 is N;

[0245] Each time L appears, it is selected from the following groups, either the same or different: single bond, substituted or unsubstituted aryl group with 6-30 carbon atoms, substituted or unsubstituted heteroaryl group with 3-30 carbon atoms, and combinations thereof.

[0246] In Equations 7 and 8, Z4 is selected from CR4 or N each time it appears, and at least one Z4 is N;

[0247] Z is selected from O or S each time it appears, either identically or differently;

[0248] R7-R 10 Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0249] Adjacent substituent R 10 They can be arbitrarily connected to form a ring.

[0250] In this paper, "adjacent substituent R" 10 "Can be optionally linked to form a ring" is intended to indicate that adjacent substituent groups therein, for example, two adjacent substituents R 10 These substituents can connect to form a ring. Obviously, these substituents can also remain unconnected to form a ring.

[0251] According to one embodiment of the present invention, the first main compound is selected from the group consisting of compounds N-1-1 to N-1-60, compounds N-2-1 to N-2-35, compounds N-3-1 to N-3-9, compounds N-4-1 to N-4-34 and compounds NH-1 to NH-251.

[0252]

[0253]

[0254]

[0255]

[0256]

[0257]

[0258]

[0259]

[0260]

[0261]

[0262]

[0263]

[0264]

[0265]

[0266]

[0267]

[0268] Optionally, the hydrogen in the structures of compounds N-1-1 to N-1-53, N-1-58, N-2-1 to N-2-32, N-3-1 to N-3-7, N-4-1 to N-4-34, and NH-1 to NH-251 can be partially or completely replaced by deuterium.

[0269] According to one embodiment of the present invention, the host compound further comprises a second host compound, the second host compound being a p-type host compound having a structure represented by any one of Formulas 9 to 11:

[0270]

[0271] L 11 Selected from single bonds, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof;

[0272] Ar 11 Selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted amino groups having 0-30 carbon atoms, or combinations thereof;

[0273] G' is selected from C(R) each time it appears, either identically or differently. g ')2、NR g ', O or S;

[0274] V is selected from C and CR each time it appears, either identically or differently. 12 Or N;

[0275] R 12 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution;

[0276] R 12 R g Each time it appears, it is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 ring atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0277] Adjacent substituent R 12 They can be arbitrarily connected to form a ring.

[0278] In this paper, "adjacent substituent R" 12 "Can be optionally linked to form a ring" is intended to indicate that adjacent substituent groups therein, for example, two adjacent substituents R 12 These substituents can connect to form a ring. Obviously, these substituents can also remain unconnected to form a ring.

[0279] According to one embodiment of the present invention, the second main compound is selected from the group consisting of compounds P-1 to P-67 and compounds PH-1 to PH-241:

[0280]

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291]

[0292] According to one embodiment of the present invention, optionally, the hydrogen in the structure of compounds P-1 to P-23, compounds P-27 to P-67, and compounds PH-1 to PH-241 may be partially or completely replaced by deuterium.

[0293] According to one embodiment of the present invention, the sensitizing material S1 is doped with a concentration of Y1 in the first light-emitting layer, wherein Y1 satisfies the following: 0% < Y1 ≤ 30%.

[0294] According to one embodiment of the present invention, Y1 satisfies the following condition: 8% < Y1 ≤ 15%.

[0295] According to one embodiment of the present invention, the sensitizing material S4 is doped with a concentration of Y4 in the second light-emitting layer, wherein Y4 satisfies the following: 0% < Y4 ≤ 30%.

[0296] According to one embodiment of the present invention, Y4 satisfies the following condition: 6% < Y4 ≤ 15%.

[0297] According to one embodiment of the present invention, the sensitizing material S5 is doped at a concentration of Y5 in the third light-emitting layer, wherein Y5 satisfies the following: 0% < Y5 ≤ 30%.

[0298] According to one embodiment of the present invention, Y5 satisfies the following condition: 2% < Y5 ≤ 10%.

[0299] According to one embodiment of the present invention, an electronic device is also disclosed, which includes the white organic electroluminescent device described in any of the foregoing embodiments.

[0300] Combination with other materials

[0301] The materials described in this invention for specific layers in organic light-emitting devices can be used in combination with a variety of other materials present in the device. These combinations of materials are described in detail in paragraphs 0132-0161 of U.S. Patent Application US2016 / 0359122A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned herein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0302] Materials described herein for use in specific layers of organic light-emitting devices can be used in combination with a variety of other materials present in said devices. For example, the compounds disclosed herein can be used in combination with a variety of light-emitting dopants, substrates, transport layers, blocking layers, implantation layers, electrodes, and other possible layers. These combinations of materials are described in detail in paragraphs 0080-0101 of U.S. Patent Application US2015 / 0349273A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned herein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0303] In the examples of material synthesis, unless otherwise stated, all reactions were carried out under nitrogen protection. All reaction solvents were anhydrous and used as is from commercial sources. The synthesized products were structurally confirmed and characterized using one or more instruments conventional in the art (including but not limited to Bruker's nuclear magnetic resonance spectrometer, Shimadzu's liquid chromatograph, liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, differential scanning calorimeter, Shanghai Lingguang Technology's fluorescence spectrophotometer, Wuhan Kesite's electrochemical workstation, Anhui Beiyike's sublimation apparatus, etc.) in methods well known to those skilled in the art. In the examples of devices, the characteristics of the devices were also tested using equipment conventional in the art (including but not limited to evaporation machines manufactured by Angstrom Engineering, optical testing systems and lifetime testing systems manufactured by Suzhou Fushida, ellipsometers manufactured by Beijing Liangtuo, etc.) in methods well known to those skilled in the art. Since those skilled in the art are familiar with the use of the above-mentioned equipment, testing methods, and other related content, and can obtain the inherent data of the samples definitively and unaffected, the above-mentioned related content will not be elaborated further in this patent.

[0304] In a light-emitting device, the anode material can be an electrode material with a high work function. For example, in the case of a low-emission structure, the anode material can be a transparent oxide, such as ITO (Indium Tin Oxide), while the cathode material can be an electrode material with a low work function. For example, the cathode material can be a metallic material or a mixture of different metals, such as Al, Ag, or Mg. To improve light extraction efficiency, the aforementioned light-emitting device also includes an optical capping layer (CPL) located on the side of the cathode away from the anode. The optical capping layer can increase the light extraction of the light-emitting device. For example, the optical capping layer can be a small-molecule material with a high refractive index greater than or equal to 1.8. The optical capping layer can be formed using a vapor deposition process. The thickness of the optical capping layer can range from 60 nm to 100 nm.

[0305] In some examples, the aforementioned light-emitting device further includes: a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL) sequentially stacked on the anode between the anode and the first light-emitting layer. Exemplarily, the hole injection layer is used to lower the potential barrier for hole injection and improve the efficiency of hole injection. The thickness of the hole injection layer ranges from 1 nm to 30 nm. The hole transport layer is used to transport holes. The hole transport layer has a thickness ranging from 1 nm to 200 nm. In some examples, the hole transport layer is a single layer; in others, it can be composed of a first hole transport layer and a second hole transport layer, where the HOMO of the first hole transport layer is greater than that of the second. In still others, the hole transport layer can consist of a first hole transport layer, a second hole transport layer, and a third hole transport layer, where the HOMO of the first hole transport layer is greater than that of the second, and the HOMO of the second is greater than that of the third. This reduces the hole transport barrier, increases the hole transport capacity, and is beneficial for reducing device voltage and regulating the injection balance of holes and electrons. The electron blocking layer can transport holes to the emissive layer and also block electrons and excitons. The thickness of the electron blocking layer ranges from 1 nm to 90 nm. The triplet state of the electron blocking layer is greater than that of the host compound of the first emissive layer, and the HOMO of the electron blocking layer is greater than that of the host compound of the first emissive layer. It also includes a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL) stacked sequentially on the emitting layer (EML). The hole blocking layer is used to transport electrons to the emitting layer while blocking holes and excitons. The thickness of the hole blocking layer ranges from 5 nm to 30 nm. The triplet state of the hole blocking layer is greater than that of the host compound of the first emitting layer, which in turn is greater than that of the third sensitizing material. The LUMO of the hole blocking layer is greater than that of the host compound of the third emitting layer. The electron transport layer is used to transport electrons. The thickness of the electron transport layer ranges from 10 nm to 70 nm. The electron injection layer is used to lower the electron injection barrier and can be a low work function metal, such as Yb (ytterbium), or a metal salt such as LiF (lithium fluoride). The thickness of the electron injection layer ranges from 0.5 nm to 2 nm.The HOMO of compounds in the organic layer with a specific interval between the first and second luminescent layers lies between the HOMOs of any host compound in the first and second luminescent layers. Similarly, the HOMO of compounds in the organic layer with a specific interval between the second and third luminescent layers lies between the HOMOs of any host compound in the second and third luminescent layers. The hole transport region includes a hole injection layer and a hole transport layer, and the electron transport region includes an electron transport layer and an electron injection layer.

[0306] As described in this article, the refractive index testing method for each organic layer of the organic electroluminescent device is as follows: a 30 nm thick material is deposited on a silicon wafer using an Angstrom Engineering evaporation machine, and the refractive index curves with wavelengths ranging from 400 nm to 800 nm are obtained using an ellipsometer (model ES Nano) from Beijing Liangtuo Technology Co., Ltd. Furthermore, the refractive index parameters for the glass, cathode layer material, anode materials Ag and ITO, and EIL material Yb are all derived from the refractive index library included in the SETFOS optical simulation software. Details are shown in Table 1.

[0307] Table 1

[0308]

[0309] As used herein, the term "single-layer device" refers to a device with one and only one emitting layer between a pair of anodes and cathodes, along with associated hole transport, electron transport, etc. As described herein, the method for testing the electroluminescence spectrum (EL spectrum) of the emitting layer is as follows: a single-layer device is fabricated in an Angstrom Engineering evaporation machine, and its electroluminescence spectrum is tested using an optical testing system manufactured by Suzhou Fosstar Co., Ltd., with a wavelength range of 400-750 nm. Through the fabrication and testing of the single-layer device, the emitting layer EL spectrum can be obtained for optical simulation.

[0310] The fabrication method of organic electroluminescent devices is not limited. The fabrication method of the following monolayer device is merely an example and should not be construed as limiting. Those skilled in the art can reasonably improve the fabrication method of the following monolayer device based on existing technology. For example, the proportions of various materials in the luminescent layer are not particularly limited. Those skilled in the art can reasonably select them within a certain range based on existing technology. For instance, based on the total weight of the luminescent layer materials, the main compound can account for 80%-99%, and the luminescent material can account for 1%-20%; or the main compound can account for 90%-99%, and the luminescent material can account for 1%-10%; or the main compound can account for 95%-99%, and the luminescent material can account for 1%-5%. Furthermore, the main compound can contain one or two materials, wherein the ratio of the two main compounds to the main compound can be 100:0 to 1:99; or, the ratio can be 80:20 to 20:80; or, the ratio can be 60:40 to 40:60. In single-layer devices, the characteristics of the device are also tested using conventional equipment in the art (including but not limited to evaporation machines manufactured by Angstrom Engineering, optical testing systems and lifetime testing systems manufactured by Suzhou Fushida, ellipsometers manufactured by Beijing Liangtuo, etc.) and methods well known to those skilled in the art. Since those skilled in the art are familiar with the use of the above-mentioned equipment, testing methods, and other related content, and can obtain the inherent data of the sample reliably and unaffected, the above-mentioned related content will not be elaborated further in this invention.

[0311] Single-layer device D1: First, a 0.7mm thick glass substrate is used, on which a pre-patterned ITO is formed. As the anode. The substrate is then dried in a glove box to remove moisture and placed on a support before being transferred to the vacuum chamber. The organic layer specified below is applied at a vacuum degree of approximately 10. -6 In the case of Torr, The rate was achieved by sequentially depositing compounds HT and HI on the anode using vacuum thermal evaporation: first, compounds HT and HI were simultaneously deposited as hole injection layers (HIL, 97:3). ), the vapor-deposited compound HT is used as a hole transport layer (HTL, Next, compound P-67 was vapor-deposited as an electron blocking layer (EBL). Compounds P-25, N-3-2, Pt27, and BN-BD-52 were simultaneously deposited on it as the luminescent layer (EML, 52:35:12:1). Next, compound N-4-1 is vapor-deposited as a hole-blocking layer (HBL). Then, the compounds ET and Liq were simultaneously deposited as an electron transport layer (ETL, 40:60). Finally, vapor deposition. A thick layer of Liq is used as the electron injection layer (EIL), and finally, metallic aluminum is evaporated as the cathode. The device is then transferred back to the glove box and sealed with a glass cover to complete the device.

[0312] Monolayer device D-2: The preparation method of monolayer device D-2 is the same as that of device D-1, the only difference being that the compounds in the EML are replaced with compounds P-25, N-3-2, and BN-BD-52 (EML, 49:50:1). ).

[0313] Monolayer device D-3: The preparation method of monolayer device D-3 is the same as that of D-1, the difference being that the compound in EBL is replaced with compound PH-241 (EBL, In the EML, the compounds are replaced with compounds PH-241, NH-45, GD139, and BD-26 (EML, 46:47:6:1). In HBL, the compound is replaced with compound N-4-1 (HBL, ).

[0314] Monolayer device D-4: The preparation method of monolayer device D-4 is the same as that of D-3, the only difference being that the compounds in the EML are replaced with compounds PH-241, NH-45 and BD-26 (EML, 49:50:1). ).

[0315] Monolayer device D-5: The fabrication method of monolayer device D-5 is the same as that of device D-1, the difference being that the compound in the EBL of device D-1 is replaced with compound P-67 (EBL, In the EML, the compounds were replaced with compounds N-4-26 and RD117 (EML, 97:3). In HBL, the compound is replaced with compound N-4-1.

[0316] The partial device structure and thickness of the single-layer device, as well as the maximum emission wavelength λmax and full width at half maximum (FWHM) of the obtained EL spectrum, are shown in Table 2 below. The layers used are made of multiple materials, obtained by doping different compounds according to their stated weight ratios. The maximum emission wavelength λmax and FWHM of the EL spectrum were obtained at a current density of 10 mA / cm². 2 The following measurements were taken.

[0317] Table 2

[0318]

[0319] Among them, compound CPL54 is a capping material (refractive index n@620nm is 2.06) purchased from Jiangsu Sanyue Technology Co., Ltd. The structures of other compounds used in the device are shown below:

[0320]

[0321]

[0322] Using the single-layer device described above, we can obtain the electroluminescence spectra (EL spectra) of different light-emitting layers. See the specific spectral diagrams below. Figures 4 to 8 .

[0323] As described herein, the term "simulation" refers only to simulations performed using optical simulation software, focusing on the refractive index and thickness of each material layer and the EL spectrum corresponding to the emitting layer, excluding electrical simulations, etc. The optical simulation software used in this invention is SETFOS 5.1.1 semiconductor thin film optical simulation software developed by Fluxim AG.

[0324] Regarding the specific experiments, this paper uses data from simulation experiments.

[0325] Example 1:

[0326] First, in the device structure, the refractive index and thickness of each layer material and the EL spectrum of each light-emitting layer are substituted in a manner known to those skilled in the art. Simultaneously, by adjusting the thicknesses of different light-emitting layers and HTL layers, the color points of the simulated device are made to be substantially similar. Specifically: for 0.7mm glass, such as... Figure 3 China 201, followed by ITO, such as Figure 3 210, Ag, such as Figure 3 in 211, and ITO, such as Figure 3 212 in the middle, including such as Figure 3 210, 211, and 212 together serve as the anode; followed by HIL, such as Figure 3 220; followed by HTL, such as Figure 3 230; followed by EBL, such as Figure 3 240; followed by The EL spectrum wavelength range is 500-600 nm for green light EML, such as Figure 3 In section 251, the second emitting layer is used, and the EL spectrum obtained from the monolayer device D-3 is substituted; followed by... The EL spectrum wavelength range is 400-500 nm for blue light EML, such as Figure 3In the middle, 252 represents the first emitting layer, and the EL spectrum obtained from the monolayer device D-2 is substituted; subsequently, The EL spectrum wavelength range is red light EML in the range of 600-700 nm, such as Figure 3 In the middle, 253 represents the third emitting layer, and the EL spectrum obtained from the single-layer device D-5 is substituted, followed by... HBL, such as Figure 3 260 in the middle, followed by ETL, such as Figure 3 270, followed by Yb, such as Figure 3 280, followed by Ag, such as Figure 3 290 in China, including... Figure 3 290 is the cathode, followed by CPL, such as Figure 3 The middle 291, and finally the 0.7mm glass, such as Figure 3 202.

[0327] Example 2: The simulation method and structure are the same as in Example 1. The color spectra of the simulated devices are made nearly identical by adjusting the thicknesses of the different emitting layers and HTL layers. The difference lies in replacing the green EML (second emitting layer) with the EL spectrum obtained from the single-layer device D-4, and replacing the blue EML (first emitting layer) with the EL spectrum obtained from the single-layer device D-1. Simultaneously, the HTL is adjusted to... The second light-emitting layer is adjusted to The first light-emitting layer is The third light-emitting layer was adjusted to...

[0328] Example 3: The simulation method and structure are the same as in Example 1. By adjusting the thicknesses of the emitting layer and HTL layer, the color points of the simulated device are made essentially similar. The difference lies in replacing the blue EML (first emitting layer) with the EL spectrum obtained from the single-layer device D-1, and adjusting the HTL to... The second light-emitting layer is adjusted to The first light-emitting layer is The third light-emitting layer was adjusted to...

[0329] Comparative Example 1: Similar to Example 2 in terms of simulation method and structure, and by adjusting the thicknesses of different emitting layers and HTL layers, the color points of the simulated devices are made essentially the same. The difference lies in further replacing the blue EML, i.e., the first emitting layer, with the EL spectrum obtained from the single-layer device D-2, and simultaneously adjusting the HTL to... The second light-emitting layer is adjusted to The first light-emitting layer is The third light-emitting layer was adjusted to...

[0330] Table 3 shows the single-layer devices corresponding to the EL spectra of each emitting layer in Examples 1-3 and Comparative Example 1.

[0331] Table 3

[0332] Second light-emitting layer First light-emitting layer Third light-emitting layer serial number EL spectrum EL spectrum EL spectrum Example 1 D-3 D-2 D-5 Example 2 D-4 D-1 D-5 Example 3 D-3 D-1 D-5 Comparative Example 1 D-4 D-2 D-5

[0333] Table 4 summarizes the color coordinates (CIEx, CIEy) and current efficiency (CE) data of the analog devices of Examples 1-3 and Comparative Example 1.

[0334] Table 4

[0335]

[0336] discuss:

[0337] In the above embodiments and comparative examples, the thickness of the emitting layer and HTL layer was adjusted to make the color coordinates (CIEx, CIEy) of the simulated device closer to more reasonably compare changes in device efficiency (CE). Therefore, the main difference between Embodiments 1 and 2 and Comparative Example 1 is whether or not a sensitizing material is included in the specific emitting layer, i.e., the green emitting layer (second emitting layer) or the blue emitting layer (first emitting layer). In Comparative Example 1, none of the three emitting layers contain sensitizing materials. However, the devices in Embodiments 1 and 2, which contain sensitizing materials in the specific emitting layer, achieved significant improvements in device current efficiency (CE), increasing by 20% and 81% respectively. This demonstrates that the white organic light-emitting device of the present invention successfully obtains a high-efficiency white light device by introducing sensitizing materials to sensitize the delayed fluorescence compound in the specific emitting layer. Furthermore, in Embodiment 3, sensitizing materials are introduced simultaneously in the green emitting layer (second emitting layer) and the blue emitting layer (first emitting layer) to sensitize the delayed fluorescence compound. Embodiment 3 successfully achieved a further significant improvement in device efficiency on top of the significant improvements already achieved in Embodiments 1 and 2. This further demonstrates the unique advantages and broad application prospects of the white organic electroluminescent device of the present invention.

[0338] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments and preferred embodiments described herein. Many of the materials and structures described herein can be substituted with other materials and structures without departing from the spirit of the invention. It should be understood that various theories regarding why the invention works are not intended to be limiting.

Claims

1. A white organic electroluminescent device, comprising: anode, The cathode, and a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer disposed between the anode and the cathode; wherein at least one of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer contains at least one phosphorescent compound and at least one delayed fluorescence compound, wherein the phosphorescent compound is a sensitizing material, and the delayed fluorescence compound is a light-emitting material having a peak emission wavelength of less than 600 nm in the photoluminescence spectrum; no charge-generating layer is contained between any two of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer.

2. The white organic electroluminescent device according to claim 1, wherein the delayed fluorescence compound is a TADF compound.

3. The white light organic electroluminescent device according to claim 1 or 2, wherein the first light-emitting layer comprises a sensitizing material S1, a light-emitting material A1, and a host compound H1, wherein the light-emitting material A1 is a TADF compound and has a peak wavelength of 400-500 nm in the photoluminescence spectrum; the second light-emitting layer comprises a light-emitting material A2 and a host compound H2, wherein the light-emitting material A2 has a peak wavelength of 500-600 nm in the photoluminescence spectrum; and the third light-emitting layer comprises a light-emitting material A3 and a host compound H3, wherein the light-emitting material A3 has a peak wavelength of 600-700 nm in the photoluminescence spectrum. Preferably, the sensitizing material S1 is a phosphorescent compound, and the luminescent materials A2 and A3 are independently selected from fluorescent compounds or phosphorescent compounds, wherein the fluorescent compound is selected from TADF compounds; Preferably, the second light-emitting layer comprises a sensitizing material S4, a light-emitting material A4, and a host compound H4, wherein the sensitizing material S4 is a phosphorescent compound, and the light-emitting material A4 is a TADF compound with a peak wavelength of 500-600 nm in the photoluminescence spectrum. Preferably, the third luminescent layer comprises a sensitizing material S5, a luminescent material A5, and a host compound H5. The sensitizing material S5 is a phosphorescent compound, and the luminescent material A5 is a TADF compound with a peak wavelength of 600-700 nm in the photoluminescence spectrum.

4. The white organic electroluminescent device according to claim 3, wherein the triplet energy level of the sensitizing material S1 is T1(S1), the triplet energy level of the luminescent material A1 is T1(A1), the triplet energy level of the host compound H1 is T1(H1), T1(H1) > T1(S1) > T1(A1); and / or the highest occupied orbital energy level of the sensitizing material S1 is HOMO(S1), the highest molecularly occupied orbital energy level of the luminescent material A1 is HOMO(A1), HOMO(S1) > HOMO(A1).

5. The white organic electroluminescent device according to claim 4, wherein the triplet energy level of the sensitizing material S4 is T1(S4), the triplet energy level of the luminescent material A4 is T1(A4), the triplet energy level of the host compound H4 is T1(H4), T1(H4) > T1(S4) > T1(A4); and / or the highest occupied orbital energy level of the sensitizing material S4 is HOMO(S4), the highest molecularly occupied orbital energy level of the luminescent material A4 is HOMO(A4), HOMO(S4) > HOMO(A4).

6. The white organic electroluminescent device according to claim 4, wherein the triplet energy level of the sensitizing material compound S5 is T1(S5), the triplet energy level of the luminescent material A5 is T1(A5), the triplet energy level of the host compound H5 is T1(H5), T1(H5) > T1(S5) > T1(A5); and / or the highest occupied orbital energy level of the sensitizing material S5 is HOMO(S5), the highest molecularly occupied orbital energy level of the luminescent material A5 is HOMO(A5), HOMO(S5) > HOMO(A5).

7. The white organic electroluminescent device according to claim 3, wherein a second light-emitting layer, a first light-emitting layer and a third light-emitting layer are sequentially disposed from the anode to the cathode, or a first light-emitting layer, a second light-emitting layer and a third light-emitting layer, or a third light-emitting layer, a first light-emitting layer and a second light-emitting layer; or a second light-emitting layer, a first light-emitting layer, a third light-emitting layer and a first light-emitting layer, wherein the two first light-emitting layers are the same or different; or a second light-emitting layer, a third light-emitting layer, a second light-emitting layer and a first light-emitting layer, wherein the two second light-emitting layers are the same or different.

8. The white organic electroluminescent device according to claim 3, wherein the first light-emitting layer and the second light-emitting layer are in direct contact, or the first light-emitting layer and the second light-emitting layer are separated by an organic layer 1, wherein the two sides of the organic layer 1 are in direct contact with the first light-emitting layer and the second light-emitting layer respectively; preferably, the HOMO energy level of the compound in the organic layer 1 is between the HOMO energy level of any host compound in the first light-emitting layer and the HOMO energy level of any host compound in the second light-emitting layer.

9. The white organic electroluminescent device according to claim 3, wherein the second light-emitting layer and the third light-emitting layer are in direct contact, or the second light-emitting layer and the third light-emitting layer are separated by an organic layer 2, wherein the two sides of the organic layer 2 are in direct contact with the second light-emitting layer and the third light-emitting layer respectively; preferably, the HOMO energy level of the compound in the organic layer 2 is between the HOMO energy level of any host compound in the second light-emitting layer and the HOMO energy level of any host compound in the third light-emitting layer.

10. The white organic electroluminescent device according to claim 3, wherein the first light-emitting layer and the third light-emitting layer are in direct contact, or the first light-emitting layer and the third light-emitting layer are separated by an organic layer 3, wherein the two sides of the organic layer 3 are in direct contact with the first light-emitting layer and the third light-emitting layer respectively; preferably, the HOMO energy level of the compound in the organic layer 3 is between the HOMO energy level of any host compound in the first light-emitting layer and the HOMO energy level of any host compound in the third light-emitting layer.

11. The white organic electroluminescent device according to any of claims 1 to 10, wherein the phosphorescent compound is a metal complex having the general formula M(L a ) m (L b ) n (L c ) q ; M is selected from metals with a relative atomic mass greater than 40; Ligands L a , L b and L c are respectively a first ligand, a second ligand and a third ligand coordinated to the metal M, the ligands L a , L b and L c may be the same or different; ligand L a , L b and L c may optionally be linked to form a polydentate ligand; m is 1, 2 or 3; n is 0, 1 or 2; q is 0, 1 or 2; the sum of m, n, q is equal to the oxidation state of the metal M; when m is equal to or greater than 2, the plurality of L a may be the same or different; when n is 2, the two L b may be the same or different; when q is 2, the two L c may be the same or different; Ligand L a having a structure as shown in Formula 1 : When ring F and ring G appear, they are selected, either in the same or different, from unsaturated carbon rings having 5-30 carbon atoms, unsaturated heterocycles having 1-30 carbon atoms, or combinations thereof. X1 and X2 are selected from C or N each time they appear, either in the same or different ways. K1 and K2 are each independently selected from a single bond, O or S; A1is selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , (CR q R q ) y , substituted or unsubstituted arylene having 6 to 30 carbon atoms, substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof; y is the same or different at each occurrence and is selected from 1, 2, 3, 4, or 5; R f and R g identically or differently in each occurrence, represent mono-, poly- or no substitution; R f , R g and R q are the same or different at each occurrence and are selected from the group consisting of hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl having from 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl having from 3-20 ring carbon atoms, a substituted or unsubstituted heteroalkyl having from 1-20 carbon atoms, a substituted or unsubstituted heterocyclyl having from 3-20 ring atoms, a substituted or unsubstituted aralkyl having from 7-30 carbon atoms, a substituted or unsubstituted alkoxy having from 1-20 carbon atoms, a substituted or unsubstituted aryloxy having from 6-30 carbon atoms, a substituted or unsubstituted alkenyl having from 2-20 carbon atoms, a substituted or unsubstituted alkynyl having from 2-20 carbon atoms, a substituted or unsubstituted aryl having from 6-30 carbon atoms, a substituted or unsubstituted heteroaryl having from 3-30 carbon atoms, a substituted or unsubstituted alkylsilicon having from 3-20 carbon atoms, a substituted or unsubstituted arylsilane having from 6-20 carbon atoms, a substituted or unsubstituted alkyl germanium having from 3-20 carbon atoms, a substituted or unsubstituted aryl germanium having from 6-20 carbon atoms, a substituted or unsubstituted amino having from 0-20 carbon atoms, acyl, carbonyl, carboxylic acid group, ester group, cyano, isocyano, hydroxyl, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; adjacent substituents R f , R g and R q may optionally be linked to form a ring.

12. The white organic electroluminescent device according to any one of claims 1-10, wherein the phosphorescent compound has a structure represented by any one of formulas 5-1 to 5-24: in, A2is, on each occurrence, the same or different, selected from a single bond, O, S, Se, (SiR q R q ) y , PR q , NR q , substituted or unsubstituted arylene having 6 to 30 carbon atoms, substituted or unsubstituted heteroarylene having 3 to 30 carbon atoms, or a combination thereof; y is, on each occurrence, the same or different, selected from 1, 2, or 3; U1-U 20 independently at each occurrence, selected from CR n or N; Each time ring F3 appears, it is selected from unsaturated carbon rings having 5-30 carbon atoms, unsaturated heterocycles having 3-30 carbon atoms, or combinations thereof; Q is selected from O, S, or Se each time it appears, either the same or different. Each time m appears, it is selected from 0, 1, 2, or 3, either the same or different. R u , R f3 each occurrence, identically or differently, represents mono-, poly- or non- substitution; R, R N , R q , R u , R n , R f3 , R a , R b and R c are each, the same or different at each occurrence, selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl with 1-20 carbon atoms, substituted or unsubstituted cycloalkyl with 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl with 1-20 carbon atoms, substituted or unsubstituted heterocyclyl with 3-20 ring atoms, substituted or unsubstituted aralkyl with 7-30 carbon atoms, substituted or unsubstituted alkoxy with 1-20 carbon atoms, substituted or unsubstituted aryloxy with 6-30 carbon atoms, substituted or unsubstituted alkenyl with 2-20 carbon atoms, substituted or unsubstituted alkynyl with 2-20 carbon atoms, substituted or unsubstituted aryl with 6-30 carbon atoms, substituted or unsubstituted heteroaryl with 3-30 carbon atoms, substituted or unsubstituted alkylsilicon with 3-20 carbon atoms, substituted or unsubstituted arylsilicon with 6-20 carbon atoms, substituted or unsubstituted alkyl germanium with 3-20 carbon atoms, substituted or unsubstituted aryl germanium with 6-20 carbon atoms, substituted or unsubstituted amino with 0-20 carbon atoms, acyl, carbonyl, carboxylic acid group, ester group, cyano, isocyano, hydroxyl, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; adjacent substituents R, R N , R q , R u , R n and R f3 may optionally be joined to form a ring.

13. The white organic electroluminescent device according to any one of claims 2-10, wherein the TADF compound has the following general formula: in, Ring A, ring B and ring C are each independently selected from five-membered unsaturated carbon rings, aromatic rings with 6-30 carbon atoms, heteroaromatic rings with 3-30 carbon atoms, or combinations thereof; Y is independently at each occurrence selected from B, CR z , SiR z , GeR z , N, P or P=O; E1and E2are each independently at each occurrence selected from a single bond, BR z , CR z R z , SiR z R z , GeR z R z , NR z , PR z , P=O(R z ), O, S, S=O, Se or Se=O; R a1 , R b1 , R c1 identically or differently at each occurrence, denotes mono-, poly- or un- substituted; R a1 , R b1 , R c1 , R z is, at each occurrence, independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl with 1-20 carbon atoms, substituted or unsubstituted cycloalkyl with 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl with 1-20 carbon atoms, substituted or unsubstituted heterocyclyl with 3-20 ring atoms, substituted or unsubstituted aralkyl with 7-30 carbon atoms, substituted or unsubstituted alkoxy with 1-20 carbon atoms, substituted or unsubstituted aryloxy with 6-30 carbon atoms, substituted or unsubstituted alkenyl with 2-20 carbon atoms, substituted or unsubstituted aryl with 6-30 carbon atoms, substituted or unsubstituted heteroaryl with 3-30 carbon atoms, substituted or unsubstituted alkylsilicon with 3-20 carbon atoms, substituted or unsubstituted arylsilane with 6-20 carbon atoms, substituted or unsubstituted alkyl germanium with 3-20 carbon atoms, substituted or unsubstituted aryl germanium with 6-20 carbon atoms, substituted or unsubstituted amino with 0-20 carbon atoms, BR'R', acyl, carbonyl, carboxylic acid group, ester group, cyano, isocyano, hydroxyl, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; R', each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms; adjacent substituents R a1 , R b1 , R c1 , R z , R' can optionally be linked to form a ring.

14. The white organic light-emitting device according to any one of claims 2-10, wherein the TADF compound has a structure represented by any one of formulas 2-1 to 2-8: In Formulas 2-1 to 2-8, rings A, B, C, D, E, and H are each independently selected from five-membered unsaturated carbon rings, aromatic rings having 6-30 carbon atoms, heteroaromatic rings having 3-30 carbon atoms, or combinations thereof. Each of E1 to E4 is independently selected from a single key, BR z CR z R z SiR z R z GeR z R z NR z PR z P = O(R) z ), O, S, S=O, Se or Se=O; R a1 R b1 R c1 R d1 R e1 R h1 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution; R a1 R b1 R c1 R d1 R e1 R h1 R z Each occurrence is selected from the group consisting of, either identically or differently, of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and so on. The following are substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium alkyl groups having 6-20 carbon atoms, substituted or unsubstituted amino groups having 0-20 carbon atoms, BR'R', acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphin, and combinations thereof. R', each time appearing, is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted groups having 6-30 carbon atoms. The aryloxy group, substituted or unsubstituted alkenyl group having 2-20 carbon atoms, substituted or unsubstituted aryl group having 6-30 carbon atoms, substituted or unsubstituted heteroaryl group having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl group having 3-20 carbon atoms, substituted or unsubstituted arylsilyl group having 6-20 carbon atoms, substituted or unsubstituted amino group, acyl group, carbonyl group, carboxylic acid group, ester group, cyano group, isocyano group, hydroxyl group, mercapto group, sulfinyl group, sulfonyl group, phosphin group, and combinations thereof having 0-20 carbon atoms; Adjacent substituent R a1 R b1 R c1 R d1 R e1 R h1 R z R and R' can be optionally connected to form a loop.

15. The white organic light-emitting device according to any one of claims 3-10, wherein the host compound comprises a first host compound having a structure represented by any one of formulas 6 to 8: In Equation 6, Z4 is selected from CR each time it appears, either the same or different. 10 Or N, and at least one of Z4 is N; Each time L appears, it is selected from the following groups, either the same or different: single bond, substituted or unsubstituted aryl group with 6-30 carbon atoms, substituted or unsubstituted heteroaryl group with 3-30 carbon atoms, and combinations thereof. In Equations 7 and 8, Z4 is selected from CR4 or N each time it appears, and at least one Z4 is N; Z is selected from O or S each time it appears, either identically or differently; R7-R 10 Each time it appears, it is selected from the group consisting of the same or different groups of the following: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, and substituted or unsubstituted alkyl groups having 1-20 carbon atoms. Alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Adjacent substituent R 10 They can be arbitrarily connected to form a ring.

16. The white organic light-emitting device according to any one of claims 3-10, wherein the host compound further comprises a second host compound having a structure represented by any one of formulas 9 to 11: L 11 Selected from single bonds, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, or combinations thereof; Ar 11 Selected from substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted amino groups having 0-30 carbon atoms, or combinations thereof; G' is selected from C(R) each time it appears, either identically or differently. g ')2、NR g ', O or S; V is selected from C and CR each time it appears, either identically or differently. 12 Or N; R 12 Each occurrence, whether identical or different, indicates monosubstitution, polysubstitution, or no substitution; R 12 R g Each time it appears, it is selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 ring atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3-20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; Adjacent substituent R 12 They can be arbitrarily connected to form a ring.

17. An electronic device comprising the white organic electroluminescent device according to any one of claims 1-16.

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