A silicon-containing organic compound, use thereof, and an organic electroluminescent device

Abstract

This invention relates to the field of organic electroluminescent devices, and discloses a silicon-containing organic compound, its application, and an organic electroluminescent device. The compound has the structure shown in formula (I). The aforementioned organic compound provided by this invention has a high glass transition temperature, a high decomposition temperature, and a high refractive index. When applied as a capping layer on a device, it can improve the light extraction efficiency of the cathode, thereby improving the luminous efficiency of the device.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent devices, specifically to a silicon-containing organic compound and its applications, and an organic electroluminescent device. Background Technology

[0002] Currently, OLED display technology has been applied in smartphones, tablets, and other fields, and will further expand to large-size applications such as televisions. However, due to total internal reflection at the interfaces between the ITO film and the glass substrate, and between the glass substrate and air, only about 20% of the light reflected into the external space in front of the OLED device is emitted. The remaining approximately 80% of the light is mainly confined within the organic material film, ITO film, and glass substrate in the form of waveguides. There is a significant gap between the external quantum efficiency and the internal quantum efficiency of OLEDs, resulting in a relatively low light extraction efficiency (approximately 20%) for conventional OLED devices. This severely restricts the development and application of OLEDs.

[0003] Therefore, improving the light extraction efficiency of OLEDs has become a research hotspot. Currently, adding a capping layer (CPL) structure to the light-emitting surface of the substrate, adjusting the optical interference distance, suppressing external light reflection, and suppressing extinction caused by surface plasmon energy movement are important methods to improve the external quantum efficiency of OLEDs, thereby further enhancing the luminous efficiency of the device.

[0004] Therefore, providing a CPL material is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide a new organic compound that, when used in high-refractive-index CPL materials, can improve light extraction efficiency and reduce light loss by utilizing optical interference effects, thereby improving the luminous efficiency of the device.

[0006] To achieve the above objectives, the present invention provides a silicon-containing organic compound having the structure shown in formula (I).

[0007]

[0008] In equation (I),

[0009] R1 is selected from C 6-20 Aromatic groups, C 1-20 alkyl;

[0010] R2 is selected from C groups that are unsubstituted or substituted with at least one group from combination A, and may or may not contain heteroatoms of type A. 3-30 Aromatic groups; the type A heteroatoms include at least one of N, O, and S; the combination A contains C.1-20 Alkyl, amino, phenyl;

[0011] X is either S or O;

[0012] L1, L2, and L3 may or may not exist independently, and the existing L1, L2, and L3 can be independently chosen by C. 6-20 An aromatic compound is formed by removing at least one of two linking groups that can be removed by any two H atoms.

[0013] The second aspect of the present invention provides the application of the silicon-containing organic compounds described in the first aspect in organic electroluminescent devices.

[0014] A third aspect of the present invention provides an organic electroluminescent device comprising a first electrode; a second electrode disposed opposite to the first electrode; at least one organic material layer disposed between the first electrode and the second electrode; and a capping layer on a cathode, wherein the organic electroluminescent device comprises at least one of the silicon-containing organic compounds described in the first aspect.

[0015] The aforementioned organic compounds provided by this invention have high glass transition temperature, decomposition temperature and high refractive index. When applied to devices (e.g., on a capping layer), they can improve the light extraction efficiency of the cathode, thereby improving the luminous efficiency of the device. Detailed Implementation

[0016] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0017] In this invention, unless otherwise specified, groups of the same type have similar interpretations, and will not be described in detail here.

[0018] In this invention, "aromatic compound" and "aromatic group" are interpreted broadly to refer to cyclic compounds or groups that contain at least one delocalized bond and are thus "aromatic".

[0019] "C containing or not containing type A heteroatoms" 3-30"Aromatic group" means that the number of carbon atoms in the aromatic group is 3-30 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30). The aromatic group may or may not contain heteroatoms.

[0020] "By C" 6-20 The aromatic compound is described as having at least one of the following linkage groups formed by any two H atoms that can leave: the aromatic compound has 6-20 carbon atoms (e.g., 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20), and does not contain heteroatoms; the linkage group can also be selected from C. 6-20 Aromatic compounds can form two or more linking groups by removing any two H atoms that can leave their bonds. For example, naphthalene and benzene both remove two H atoms and bond with each other to form linking groups.

[0021] “C 1-20 "Alkyl" refers to a straight-chain or branched alkyl group with a total number of carbon atoms of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. 1-10 Alkyl" "C" 1～8 Alkyl", C 1～6 Alkyl", C 1～3 Alkyl groups have similar definitions, differing only in the total number of carbon atoms.

[0022] When the compounds of the present invention contain substituents, there are no particular requirements on the specific substitution position of the substituents; they can be any position that can be substituted.

[0023] As previously described, a first aspect of the present invention provides a silicon-containing organic compound having the structure shown in formula (I).

[0024]

[0025] In equation (I),

[0026] R1 is selected from C 6-20 Aromatic groups, C 1-20 alkyl;

[0027] R2 is selected from C groups that are unsubstituted or substituted with at least one group from combination A, and may or may not contain heteroatoms of type A. 3-30 Aromatic groups; the type A heteroatoms include at least one of N, O, and S; the combination A contains C.1-20 Alkyl, amino, phenyl;

[0028] X is either S or O;

[0029] L1, L2, and L3 may or may not exist independently, and the existing L1, L2, and L3 can be independently chosen by C. 6-20 An aromatic compound is formed by removing at least one of two linking groups that can be removed by any two H atoms.

[0030] Preferably, in formula (I),

[0031] R1 is selected from phenyl, diphenyl, naphthyl, anthraceneyl, phenanthryl, terphenyl, C 1-12 alkyl;

[0032] R2 is selected from C groups that are unsubstituted or substituted by at least one group from combination A and may or may not contain heteroatoms of type A. 3-24 Aromatic groups; the type A heteroatoms include at least one of N, O, and S; the combination A contains C. 1-12 Alkyl, amino, phenyl;

[0033] X is either S or O;

[0034] L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

[0035] More preferably, in equation (I),

[0036] R1 is selected from phenyl, diphenyl, naphthyl, anthraceneyl, phenanthryl, terphenyl, C 1-8 alkyl;

[0037] R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl;

[0038] X is either S or O;

[0039] L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

[0040] According to a preferred embodiment (hereinafter referred to as preferred embodiment 1), in formula (I),

[0041] R1 is a phenyl group;

[0042] R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl;

[0043] X is either S or O;

[0044] L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

[0045] In the preferred embodiment 1, more preferably, the silicon-containing organometallic compound with the structure shown in formula (I) is selected from any one of the following:

[0046]

[0047]

[0048]

[0049] According to a preferred embodiment (hereinafter referred to as preferred embodiment 2), in formula (I),

[0050] R1 is C 1-6 alkyl;

[0051] R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl;

[0052] X is either S or O;

[0053] L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

[0054] In the preferred embodiment 2, more preferably, R1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, or n-hexyl.

[0055] In a preferred embodiment 2, more preferably, the silicon-containing organic compound with the structure shown in formula (I) is selected from any one of the following:

[0056]

[0057]

[0058]

[0059] According to a particularly preferred embodiment, the silicon-containing organometallic compound with the structure shown in formula (I) is selected from any one of the following:

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] This invention does not impose any particular limitation on the specific methods for preparing the aforementioned compounds. Those skilled in the art can obtain the aforementioned compounds of this invention by combining the specific structural formulas provided by this invention with known process routes in the field of organic synthesis. Furthermore, several examples are exemplarily listed below to illustrate the preparation methods of the compounds of this invention. Those skilled in the art can also obtain the specific preparation methods of all other compounds by changing the types of raw materials according to the preparation methods of the compounds described below. This invention will not further describe the preparation methods of all compounds in detail, and this should not be construed as a limitation of the invention.

[0066] As previously stated, the second aspect of the present invention provides the use of the silicon-containing organic compounds described in the first aspect in organic electroluminescent devices.

[0067] Preferably, the silicon-containing organic compound is present in at least one of the hole transport layer, electron blocking layer, and capping layer of the organic electroluminescent device.

[0068] Particularly preferably, the compound is present in the capping layer on the cathode surface of the organic electroluminescent device.

[0069] As previously described, a third aspect of the present invention provides an organic electroluminescent device comprising a first electrode; a second electrode disposed opposite to the first electrode; at least one organic material layer disposed between the first electrode and the second electrode; and a capping layer on a cathode, wherein the organic electroluminescent device comprises at least one of the silicon-containing organic compounds described in the first aspect.

[0070] Preferably, the covering layer contains the silicon-containing organic compound.

[0071] Preferably, one of the first electrode and the second electrode of the present invention is an anode and the other is a cathode.

[0072] Preferably, the organic material layer contains a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0073] According to a preferred embodiment of the present invention, the organic electroluminescent device of the present invention includes a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, and an electron injection layer as organic material layers.

[0074] The organic electroluminescent device of the present invention preferably employs a sublimation method to coat one or more layers. In this case, in a vacuum sublimation system, at a temperature of less than 10... -3 Pa, preferably less than 10 -6 The compound provided by the present invention is applied by vapor deposition at an initial pressure of Pa.

[0075] The organic electroluminescent device of the present invention is preferably coated with one or more layers by organic vapor deposition or by means of carrier gas sublimation. In this case, at 10 -6 The compound is applied under pressures ranging from Pa to 100 Pa. A particular example of this method is the organic vapor deposition printing method, in which the compound provided by the present invention is applied directly through a nozzle to form a device structure.

[0076] The organic electroluminescent device of the present invention preferably involves formulating the compound of the present invention into a solution and forming one or more layers by spin coating or by any printing method, such as screen printing, flexographic printing, inkjet printing, offset printing, and more preferably photoinitiated thermal imaging or inkjet printing. Typically, when fabricating multiple layers using this method, layer-to-layer destruction is likely to occur; that is, when one layer is completed and another layer is fabricated using the solution, the solvent in the solution can destroy the already formed layer, which is detrimental to the fabrication of organic electroluminescent devices. However, the compound provided by the present invention can undergo cross-linking under heating or ultraviolet exposure, thereby maintaining the integrity of the layers without destruction. The compound of the present invention can also be applied from a solution and subsequently cross-linked in a polymer network or immobilized in the corresponding layers.

[0077] The organic electroluminescent device of the present invention can be manufactured as a hybrid system by applying one or more layers through solution and by applying one or more other layers through vapor deposition.

[0078] According to some embodiments of the present invention, the anode material forming the anode is generally preferably a material with a large work function, thereby enabling the reduction of the hole injection barrier. For example, the anode material that can be used in the present invention is selected from one or more of the following materials: metals, such as vanadium, chromium, copper and gold, or other alloys; metal oxides, such as zinc oxide, indium oxide, indium tin oxide, indium zinc oxide and tin dioxide; combinations of metals and oxides, such as zinc oxide and aluminum, but not limited thereto.

[0079] According to some embodiments of the present invention, the material forming the hole injection layer is, for example, a hole injection material. Preferred compounds for the hole injection material should have the ability to transport holes, thus exhibiting a hole injection effect into the anode, providing excellent hole injection for the light-emitting layer or light-emitting material, preventing excitons generated in the light-emitting layer from migrating to the electron injection layer or electron injection material, and further exhibiting excellent thin film forming ability. The HOMO of the hole injection material is preferably between that of the anode material and the HOMO of the surrounding organic material layer.

[0080] According to some embodiments of the present invention, the material forming the hole transport layer is, for example, a hole transport material capable of receiving holes from the anode or hole injection layer, moving holes to the light-emitting layer, and having a high mobility for holes.

[0081] According to some embodiments of the present invention, the hole injection material and the hole transport material include at least one of the following: aromatic amine derivatives (e.g., NPB, SqMA1), hexaazabenzophenanthrene derivatives (e.g., HACTN), indolecarbazole derivatives, conductive polymers (e.g., PEDOT / PSS), phthalocyanine or porphyrin derivatives, dibenzoindofluoreneamine, and spirodifluoreneamine, but are not limited thereto.

[0082] According to some embodiments of the present invention, the hole injection layer and the hole transport layer may, for example, be formed using aromatic amine derivatives of the following general formula:

[0083]

[0084] The groups R1 to R9 in the above general formula are each independently selected from single bonds, hydrogen, deuterium, alkyl, benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, fluorene, dimethylfluorene, spirodifluorene, carbazole, thiophene, benzo[a]thiophene, dibenzo[a]thiophene, furan, benzo[a]furan, dibenzo[a]furan, indole, indolecarbazole, indolecarbazole, pyridine, pyrimidine, imidazole, thiazole, quinoline, isoquinoline, quinoxaline, quinazoline, porphyrin, carboline, pyrazine, pyridazine, or triazine.

[0085] According to some embodiments of the present invention, the material for forming the electron blocking layer is not particularly limited; generally, compounds that meet the first and / or second condition below can be considered for use:

[0086] First: It has a high LUMO energy level, the purpose of which is to reduce the number of electrons leaving the luminescent layer, thereby increasing the recombination probability of electrons and holes in the luminescent layer.

[0087] Second: It possesses a large triplet energy, the purpose of which is to reduce the number of excitons leaving the luminescent layer, thereby improving the efficiency of exciton conversion luminescence.

[0088] According to some embodiments of the present invention, the materials of the electron blocking layer include, but are not limited to, aromatic amine derivatives (e.g., NPB) and spirodifluoreneamine (e.g., SpMA2), wherein some electron blocking materials have structures similar to hole injection materials and hole transport materials.

[0089] According to some embodiments of the present invention, the luminescent material of the luminescent layer is a material capable of emitting light in the visible light region by receiving holes and electrons from the hole transport layer and the electron transport layer respectively and combining the holes and electrons, and preferably a material with good quantum efficiency for fluorescence or phosphorescence.

[0090] According to some embodiments of the present invention, the light-emitting layer may comprise a host material and a dopant material.

[0091] According to some embodiments of the present invention, the main material may include anthracene derivatives, carbazole derivatives, fluorene derivatives, aromatic amine derivatives, organosilicon derivatives, carbazole-triazine derivatives, phosphorooxygen derivatives, but is not limited thereto.

[0092] According to some embodiments of the present invention, the anthracene derivatives have the following general formula:

[0093]

[0094] Preferably, the phosphorooxylated derivative has the following general formula:

[0095]

[0096] In the general formulas of the aforementioned anthracene derivatives and phosphoroyl derivatives, R 11 R 12 R 13 R 14 R 15 and R 16 Each group is independently selected from single bonds, hydrogen, deuterium, alkyl, benzene, diphenyl, terphenyl, tetraphenyl, naphthalene, phenylnaphthalene, anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, fluorene, carbazole, thiophene, benzo[a]thiophene, dibenzo[a]thiophene, furan, benzo[a]furan, dibenzo[a]furan, indole, indolecarbazole, indolecarbazole, pyridine, pyrimidine, imidazole, thiazole, quinoline, isoquinoline, quinoxaline, quinazoline, porphyrin, carboline, pyrazine, pyridazine, or triazine, and groups represented by their substituted derivatives.

[0097] According to some embodiments of the present invention, the guest material is preferably a compound that emits light via at least one of phosphorescence, fluorescence, TADF (thermally activated delayed fluorescence), MLCT (metal-to-ligand charge transfer), HLCT (with hybrid CT state), and triplet-triplet annihilation methods.

[0098] According to some embodiments of the present invention, the guest material in the light-emitting layer may include, but is not limited to, perylene derivatives, anthracene derivatives, fluorene derivatives, stilbene aromatic derivatives, aromatic amine derivatives, organosilicon derivatives, organoboron derivatives, carbazole-triazine derivatives, acridine derivatives, ketone derivatives, sulfone derivatives, cyano derivatives, and xanthene derivatives.

[0099] According to some embodiments of the present invention, the sulfone-based derivatives have the following general formula:

[0100]

[0101] Preferably, the ketone derivative has the following general formula:

[0102]

[0103] In the aforementioned general formulas for sulfone derivatives and ketone derivatives, R 20 R 21 R 22 and R 23 Each group is independently selected from single bonds, hydrogen, deuterium, alkyl, benzene, diphenyl, terphenyl, tetraphenyl, naphthalene, phenylnaphthalene, anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, fluorene, carbazole, thiophene, benzo[a]thiophene, dibenzo[a]thiophene, furan, benzo[a]furan, dibenzo[a]furan, indole, indolecarbazole, indolecarbazole, pyridine, pyrimidine, imidazole, thiazole, quinoline, isoquinoline, quinoxaline, quinazoline, porphyrin, carboline, pyrazine, pyridazine, or triazine, and groups represented by their substituted derivatives.

[0104] According to some embodiments of the present invention, the material of the hole blocking layer is preferably a compound having the following first and / or second condition:

[0105] First: It has a high HOMO energy level, the purpose of which is to reduce the number of holes leaving the emissive layer, thereby increasing the recombination probability of electrons and holes in the emissive layer.

[0106] Second: It possesses a large triplet energy, the purpose of which is to reduce the number of excitons leaving the luminescent layer, thereby improving the efficiency of exciton conversion luminescence.

[0107] According to some embodiments of the present invention, the material of the hole blocking layer may include, but is not limited to, phenanthroline derivatives (e.g., Bphen, BCP), benzo[a]phenanthrene derivatives, benzimidazole derivatives.

[0108] According to some embodiments of the present invention, the electron transport layer is a layer that receives electrons from the electron injection layer and transports them to the light-emitting layer. As an electron transport material, a material capable of receiving electrons from the cathode, moving electrons to the light-emitting layer, and having high electron mobility is suitable. Electron transport materials may also include, for example, Al complexes of 8-hydroxyquinoline; complexes containing Alq3; organic free radical compounds; hydroxyflavonoid-metal complexes, etc., but are not limited thereto.

[0109] According to some embodiments of the present invention, the electron injection layer is a layer that injects electrons from the electrode, and the electron injection material is preferably a compound that has the ability to transport electrons, has the effect of injecting electrons from the cathode, has an excellent effect of injecting electrons into the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and also has excellent thin film forming ability. The electron injection layer material may also include, for example, LiF, CsF, Cs₂CO₃, and LiQ, but is not limited thereto.

[0110] According to some embodiments of the present invention, the cathode material is generally preferably a material with a small work function, which allows electrons to be smoothly injected into the organic material layer. The cathode material that can be used in this disclosure can be selected from one or more of the following materials: Al, Mg and Ag.

[0111] According to some embodiments of the present invention, the covering layer contains the compound described in the first aspect of the present invention.

[0112] The present invention has at least the following specific advantages:

[0113] 1. The preferred embodiment of the present invention is a compound with a symmetrical structure. The inventors have discovered that compounds with symmetrical structures can have a higher refractive index, improve the light transmittance of the cathode, and improve luminous efficiency and brightness when applied as a capping layer in organic electroluminescent devices.

[0114] 2. The compounds of the present invention have good thermal stability and are not prone to crystallization or phase transition. When applied to organic electroluminescent devices, they can increase the luminous efficiency and brightness of the devices.

[0115] 3. The organic compounds of the present invention have good thermal decomposition temperature, and are not easily decomposed when the temperature is increased during vapor deposition, which can improve production capacity.

[0116] 4. When the compounds of the present invention are applied to organic electroluminescent devices, the current density can be reduced and the service life can be increased while ensuring brightness.

[0117] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, all raw materials used are commercially available products.

[0118] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, all raw materials used are commercially available products. Unless otherwise specified, room temperature as mentioned below refers to 25±1℃.

[0119] Preparation Example 1

[0120]

[0121] Synthesis of Intermediate 1-1: In a 500 ml three-necked flask, under nitrogen protection, 1,4-dioxane solvent (123.5 ml), 4-(aniline)phenylboronic acid (50 mmol), boron pinacol ester (50 mmol), potassium acetate (125 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (0.5 mmol) were added sequentially with stirring. The mixture was heated to reflux for 4 h. HPLC analysis confirmed the reaction was complete. After cooling the reaction solution to room temperature, the solution was evaporated under reduced pressure to obtain a crude product. The crude product was dissolved in toluene solvent, heated with stirring, and refluxed. The solution was then decolorized by hot silica gel column chromatography. The filtrate was evaporated under reduced pressure to a small amount of solvent remaining. Ethanol (190 ml) was added and the mixture was stirred. Recrystallized from toluene / ethanol to obtain Intermediate 1-1 (yield: 87.8%).

[0122] Synthesis of Intermediate 1-2: In a 500 mL three-necked flask under nitrogen protection, intermediate 1-1 (40 mmol), 2-chlorobenzoxazole (40 mmol), isopropanol, water (mixed in a 3:1 ratio) (118 mL), anhydrous potassium carbonate (100 mmol), and bis(triphenylphosphine)palladium dichloride (0.4 mmol) were added sequentially. The mixture was stirred and refluxed at 80 °C for 4 h. Deionized water (150 mL) was added to the reaction mixture, and the mixture was stirred for 10 min. The organic phase was washed three times with water, and the two phases were combined and dried over anhydrous magnesium sulfate. The drying agent was filtered off, the organic solvent was evaporated, and the residue was separated by silica gel column chromatography to obtain intermediate 1-2 (yield: 78.5%).

[0123] Synthesis of Compound 1: In a 500 mL three-necked flask under nitrogen protection, bis(4-bromophenyl)diphenylsilane (35 mmol), intermediate 1-2 (70 mmol), sodium tert-butoxide (175 mmol), tris(dibenzylacetone)dipalladium (0.7 mmol), tri-tert-butylphosphine (0.7 mmol), and toluene solvent (172 mL) were added sequentially. The mixture was stirred and heated to reflux for 8 h. HPLC analysis confirmed the reaction was complete. The reaction solution was cooled to room temperature, and 300 mL of deionized water was added. The mixture was stirred, separated, and the organic phase was washed three times with water. The solvent was removed by rotary evaporation. The residue was separated by silica gel column chromatography to obtain Compound 1 (yield: 78.6%).

[0124] Mass spectrometry: C62H44N4O2Si, theoretical value: 904.32, measured value: 904.38. 1H-NMR (400MHz, CDCl3) (ppm) δ=6.96~7.04(2H, m), 7.05~7.11(4H, m), 7.20~7.31(8H, m), 7.34~7.41(16H, m), 7.42~7.49(6H, m), 7.70~7.78(8H, m).

[0125] Preparation Example 2

[0126]

[0127] Synthesis of intermediate 21-1: The synthesis method is the same as that of intermediate 1-2, yielding intermediate 21-1 (yield: 71.4%).

[0128] Synthesis of intermediate 21-2: The synthesis method is the same as that of intermediate 1-1, yielding intermediate 21-2 (yield: 88.3%).

[0129] Synthesis of intermediate 21-3: The synthesis method is the same as that of intermediate 1-2, to obtain intermediate 21-3 (yield: 73.7%).

[0130] Synthesis of compound 21: The synthesis method was the same as that of compound 1, yielding compound 21 (yield: 79.2%).

[0131] Mass spectrometry: C74H52N4S2Si, theoretical value: 1088.34, measured value: 1088.29. 1H-NMR (400MHz, CDCl3) (ppm) δ=7.14~7.21(4H, m), 7.25~7.31(6H, m), 7.34~7.41(13H, m), 7.42~7.59(17H, m), 7.71~7.78(4H, m), 7.82~7.88(4H, m), 7.98~8.06(2H, m), 8.14~8.22(2H, m).

[0132] Preparation Example 3

[0133]

[0134] Synthesis of intermediate 34-1: The synthesis method is the same as that of intermediate 1-1, yielding intermediate 34-1 (yield: 86.5%).

[0135] Synthesis of intermediate 34-2: The synthesis method is the same as that of intermediate 1-2, yielding intermediate 34-2 (yield: 78.3%).

[0136] Synthesis of compound 34: The synthesis method was the same as that of compound 1, yielding compound 34 (yield: 77.6%).

[0137] Mass spectrometry: C64H48N4O2Si, theoretical value: 932.35, measured value: 932.27. 1H-NMR (400MHz, CDCl3) (ppm) δ=0.65~0.67(6H, s), 7.25~7.31(4H, m), 7.35~7.37(4H, m), 7.37~7.42(11H, m), 7.42~7.50(6H, m), 7.51~7.58(5H, m), 7.70~7.78(12H, m).

[0138] Preparation Example 4

[0139]

[0140] Synthesis of intermediate 59-1: The synthesis method was the same as that of compound 1, yielding intermediate 59-1 (yield: 75.2%).

[0141] Synthesis of compound 59: The synthesis method was the same as that of compound 1, yielding compound 59 (yield: 78.3%).

[0142] Mass spectrometry: C62H44N4O2Si, theoretical value: 904.32, measured value: 904.27. 1H-NMR (400MHz, CDCl3) (ppm) δ=7.14~7.21(4H, m), 7.25~7.31(6H, m), 7.35~7.42(13H, m), 7.42~7.50(10H, m), 7.51~7.59(3H, m), 7.68~7.78(8H, m).

[0143] Preparation Example 5

[0144]

[0145] Synthesis of intermediate 76-1: The synthesis method was the same as that of compound 1, yielding intermediate 76-1 (yield: 75.8%).

[0146] Synthesis of compound 76: The synthesis method was the same as that of compound 1, yielding compound 76 (yield: 77.9%).

[0147] Mass spectrometry: C62H40N4O2S2Si, theoretical value: 964.24, measured value: 964.28. 1H-NMR (400MHz, CDCl3) (ppm) δ=7.22~7.35(8H, m), 7.35~7.49(18H, m), 7.49~7.57(6H, m), 7.95~8.06(4H, m), 8.14~8.24(4H, m).

[0148] Preparation Example 6

[0149]

[0150] Synthesis of intermediate 81-1: The synthesis method was the same as that of compound 1, yielding intermediate 81-1 (yield: 75.5%).

[0151] Synthesis of compound 81: The synthesis method was the same as that of compound 1, yielding compound 81 (yield: 78.6%).

[0152] Mass spectrometry: C40H32N4O2Si, theoretical value: 628.32, measured value: 628.35. 1H-NMR (400MHz, CDCl3) (ppm) δ=0.62~0.69(6H, s), 6.96~7.11(6H, m), 7.20~7.31(8H, m), 7.35~7.45(8H, m), 7.68~7.76(4H, m).

[0153] Preparation Example 7

[0154]

[0155] Synthesis of intermediate 93-1: The synthesis method is the same as that of intermediate 1-2, yielding intermediate 93-1 (yield: 74.3%).

[0156] Synthesis of compound 93: The synthesis method was the same as that of compound 1, yielding compound 93 (yield: 76.7%).

[0157] Mass spectrometry: C62H44N4O2Si, theoretical value: 904.32, measured value: 904.33. 1H-NMR (400MHz, CDCl3) (ppm) δ=6.96~7.04(2H, m), 7.05~7.11(4H, m), 7.20~7.28(4H, m), 7.34~7.41(14H, m), 7.42~7.50(4H, m), 7.52~7.58(4H, m), 7.62~7.68(4H, m), 7.69~7.76(4H, m), 7.84~7.90(4H, m).

[0158] Preparation Example 8

[0159]

[0160] Synthesis of intermediate 117-1: The synthesis method is the same as that of intermediate 1-1, yielding intermediate 117-1 (yield: 86.5%).

[0161] Synthesis of intermediate 117-2: The synthesis method is the same as that of intermediate 1-2, yielding intermediate 117-2 (yield: 77.6%).

[0162] Synthesis of compound 117: The synthesis method was the same as that of compound 1, yielding compound 117 (yield: 77.8%).

[0163] Mass spectrometry: C82H56N4O2Si, theoretical value: 1156.42, measured value: 1156.38. 1H-NMR (400MHz, CDCl3) (ppm) δ=7.10~7.12 (2H, m), 7.34~7.41 (21H, m), 7.42~7.49 (7H, m), 7.52~7.58 (6H, m), 7.60~7.68 (6H, m), 7.69~7.78 (10H, m), 7.85~7.90 (4H, m).

[0164] Fabrication of organic light-emitting devices

[0165] Device fabrication example 1:

[0166] The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) coated glass substrates were ultrasonically cleaned for 15 minutes each with deionized water, acetone, and ethanol, and then treated in a plasma cleaner for 2 minutes.

[0167] HAT-CN was deposited on the substrate as a hole injection layer at a deposition rate of 0.1 nm / s, with a total film thickness of 10 nm. Then, HT-1 was deposited as a hole transport layer at a deposition rate of 0.1 nm / s, with a total film thickness of 80 nm. Next, TCTA was deposited as an electron and exciton blocking layer at a deposition rate of 0.1 nm / s, with a film thickness of 40 nm.

[0168] The light-emitting layer of the device is vacuum-deposited on the hole layer. The light-emitting layer includes a host material and a guest material. Using a multi-source co-evaporation method, the evaporation rate of the host material DIC-TRZ is adjusted to 0.1 nm / s, and the evaporation rate of the guest material Ir(ppy)3 is set to 10% of the evaporation rate of the host material. The total evaporation film thickness is 30 nm.

[0169] An electron transport layer was deposited on the light-emitting layer. Using a multi-source co-evaporation method, the evaporation rates of ET-2 and ET-1 were both adjusted to 0.1 nm / s, and the total film thickness was 30 nm.

[0170] The cathode material was deposited by electron injection. The method of multi-source co-evaporation was used to adjust the Mg evaporation rate to 0.1 nm / s, set the Ag evaporation rate to 20% of the Mg evaporation rate, and the total evaporation film thickness was 15 nm.

[0171] Compound 1 was deposited as a capping layer on the cathode at a deposition rate of 0.1 nm / s, resulting in a total film thickness of 60 nm, thereby completing the fabrication of the organic light-emitting device.

[0172]

[0173] Device fabrication examples 2 to 10

[0174] Device fabrication examples 2 to 10 were fabricated using a method similar to that of device fabrication example 1, except that compound 1 in device fabrication example 1 was replaced with the corresponding compound in Table 1.

[0175] Device Comparison Examples 1 to 4

[0176] Comparative Examples 1 to 4 were prepared using a method similar to that used in Preparation Example 1, except that compound 1 in Preparation Example 1 was replaced with compounds Ref1, Ref2, Ref3, and Ref4, respectively.

[0177]

[0178] Device Comparison Example 5

[0179] Comparative Example 5 uses a method similar to that used in Device Fabrication Example 1 to fabricate an organic light-emitting device. The difference is that no coating layer is deposited on the cathode in this comparative example.

[0180] Test case

[0181] At a brightness of 10000 cd / m² 2 The current efficiency of the organic electroluminescent devices prepared in the preparation examples and comparative examples was measured, and the results are shown in Table 1.

[0182] Table 1

[0183]

[0184]

[0185] As can be seen from the above results, when the organic compound of the present invention is applied to an electroluminescent device, the light extraction rate can be significantly improved, and the luminous efficiency of the device is significantly improved under the same brightness.

[0186] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A silicon-containing organochemical compound, characterized in that, The compound has the structure shown in formula (I). In equation (I), R1 is selected from C 6-20 Aromatic groups, C 1-20 alkyl; R2 is selected from C groups that are unsubstituted or substituted with at least one group from combination A, and may or may not contain heteroatoms of type A. 3-30 Aromatic groups; the type A heteroatoms include at least one of N, O, and S; the combination A contains C. 1-20 Alkyl, amino, phenyl; X is either S or O; L1, L2, and L3 may or may not exist independently, and the existing L1, L2, and L3 can be independently chosen by C. 6-20 An aromatic compound is formed by removing at least one of two linking groups that can be removed by any two H atoms.

2. The silicon-containing organochemical compound according to claim 1, characterized in that, In equation (I), R1 is selected from phenyl, diphenyl, naphthyl, anthraceneyl, phenanthryl, terphenyl, C 1-12 alkyl; R2 is selected from C groups that are unsubstituted or substituted by at least one group from combination A and may or may not contain heteroatoms of type A. 3-24 Aromatic groups; the type A heteroatoms include at least one of N, O, and S; the combination A contains C. 1-12 Alkyl, amino, phenyl; X is either S or O; L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

3. The silicon-containing organochemical compound according to claim 2, characterized in that, In equation (I), R1 is selected from phenyl, diphenyl, naphthyl, anthraceneyl, phenanthryl, terphenyl, C 1-8 alkyl; R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl; X is either S or O; L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present are each independently selected from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave.

4. The silicon-containing organochemical compound according to any one of claims 1-3, characterized in that, In equation (I), R1 is a phenyl group; R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl; X is either S or O; L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present may be selected independently from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave. Preferably, the silicon-containing organometallic compound with the structure shown in formula (I) is selected from any one of the following:

5. The silicon-containing organochemical compound according to any one of claims 1-3, characterized in that, In equation (I), R1 is C 1-6 alkyl; R2 is selected from unsubstituted or substituted phenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted biphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted naphthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted anthryl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted phenanthyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted terphenyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted pyridyl groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzothiophene groups (or groups substituted with at least one group in combination A), unsubstituted or substituted dibenzofuranyl groups (or groups substituted with at least one group in combination A), and unsubstituted or substituted dimethylfluorenyl groups (or groups substituted with at least one group in combination A); wherein combination A contains C 1-12 Alkyl, amino, phenyl; X is either S or O; L1, L2, and L3 may or may not exist independently. The L1, L2, and L3 that are present may be selected independently from at least one of the following: a linking group formed by benzene leaving any two H atoms that can leave; a linking group formed by diphenyl leaving any two H atoms that can leave; a linking group formed by naphthalene leaving any two H atoms that can leave; a linking group formed by anthracene leaving any two H atoms that can leave; a linking group formed by phenanthrene leaving any two H atoms that can leave; a linking group formed by pyridine leaving any two H atoms that can leave; a linking group formed by dibenzothiophene leaving any two H atoms that can leave; and a linking group formed by dibenzofuran leaving any two H atoms that can leave. Preferably, R1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, or n-hexyl; Preferably, the silicon-containing organometallic compound with the structure shown in formula (I) is selected from any one of the following:

6. The silicon-containing organochemical compound according to any one of claims 1-3, characterized in that, The silicon-containing organometallic compound with the structure shown in formula (I) is selected from any one of the following:

7. The use of the silicon-containing organic compound according to any one of claims 1-6 in organic electroluminescent devices.

8. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a first electrode; a second electrode disposed opposite to the first electrode; at least one organic material layer disposed between the first electrode and the second electrode; and a capping layer on the cathode. The organic electroluminescent device contains at least one of the silicon-containing organic compounds according to any one of claims 1-6.

9. The organic electroluminescent device according to claim 8, characterized in that, The coating layer contains the silicon-containing organic compound.

10. The organic electroluminescent device according to claim 8, characterized in that, The organic material layer contains a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

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