Organic electroluminescent devices and their applications in display or lighting devices, light-emitting layer materials

Abstract

This application discloses an organic electroluminescent device and its application in display or lighting devices, as well as a light-emitting layer material, relating to the field of organic electroluminescent devices. The organic electroluminescent device includes: a first electrode; a second electrode disposed opposite to the first electrode; and a light-emitting layer located between the first electrode and the second electrode. The light-emitting layer comprises a host material, and the host material comprises different deuterated derivatives of the compound shown in Formula 1. In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl. This application can significantly improve the device lifetime by controlling the average deuteration rate of deuteratizable hydrogens of Ar1 and anthracene group, and Ar2 / Ar3 and carbazole group in the compound of Formula 1 to a specific range.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescent devices, specifically to an organic electroluminescent device and its application in display or lighting devices, and a light-emitting layer material. Background Technology

[0002] With the rapid development of next-generation display and lighting technologies, organic light-emitting diodes (OLEDs) have been widely used in high-end display fields due to their self-emissive, flexible, and fast response characteristics. However, the lifespan of blue light-emitting diodes is generally shorter than that of red and green light-emitting diodes, which has become a key bottleneck restricting the overall lifespan of OLED devices.

[0003] As the core functional layer of OLED devices, the material system and structural characteristics of the emissive layer have a decisive impact on the device's luminous efficiency, brightness, color purity, power consumption, and lifespan. Therefore, material design and performance optimization for the emissive layer have become a core technological path to overcome the lifespan bottleneck of blue light-emitting devices. Summary of the Invention

[0004] The technical problem addressed by this application is to improve the lifespan of blue light-emitting devices.

[0005] To address the aforementioned technical problems, a first aspect of this application provides an organic electroluminescent device, comprising: a first electrode; a second electrode disposed opposite to the first electrode; and a light-emitting layer located between the first electrode and the second electrode; the light-emitting layer comprising a host material, and the host material comprising different deuterated derivatives of the compound shown in Formula 1:

[0006] In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl.

[0007] Among the different deuterated derivatives of compounds in which Ar3 is hydrogen, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2 with carbazole group is 98%-99.4%.

[0008] And / or, in different deuterated derivatives of compounds in which Ar3 is phenyl and has the same linkage site, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3 with carbazole group is 98%-99.4%.

[0009] The second aspect of this application provides the use of the organic electroluminescent device according to the first aspect in a display or lighting device.

[0010] A third aspect of this application provides a display or lighting device comprising an organic electroluminescent device according to the first aspect.

[0011] A fourth aspect of this application provides a luminescent layer material comprising 80 wt%-99.9 wt% of a luminescent host material and 0.1 wt%-20 wt% of a luminescent guest material; wherein the luminescent host material comprises different deuterated derivatives of the compound shown in Formula 1: In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl.

[0012] Among the different deuterated derivatives of compounds in which Ar3 is hydrogen, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2 with carbazole group is 98%-99.4%.

[0013] And / or, in different deuterated derivatives of compounds in which Ar3 is phenyl and has the same linkage site, the average deuteration rate of Ar1 with anthracene is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3 with carbazole is 98%-99.4%; meanwhile, the average deuteration rate of anthracene and Ar1 is greater than the average deuteration rate of carbazole, Ar2 and Ar3.

[0014] Device testing results show that when the light-emitting layer of an organic electroluminescent device contains the aforementioned host material, the device lifespan can be significantly improved.

[0015] Device testing results show that by adjusting the average deuteration rate of Ar1 and anthracene groups, and Ar2 / Ar3 and carbazole groups in compound formula 1 to a specific range, the lifetime of organic electroluminescent devices can be significantly improved. Attached Figure Description

[0016] The following accompanying drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals denote similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting and exemplary, and the drawings are for illustrative purposes only and are not intended to limit the scope of this application. Other embodiments may similarly fulfill the inventive intent of this application. It should be understood that the drawings are not drawn to scale. Wherein:

[0017] Figure 1 The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Example 1 of this application;

[0018] Figure 2 The hydrogen nuclear magnetic spectrum of the luminescent host material prepared in Comparative Example 1 of this application;

[0019] Figure 3The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Comparative Example 2 of this application is shown below.

[0020] Figure 4 The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Comparative Example 3 of this application is shown below.

[0021] Figure 5 The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Example 2 of this application;

[0022] Figure 6 The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Comparative Example 4 of this application is shown.

[0023] Figure 7 The hydrogen nuclear magnetic resonance spectrum of the luminescent host material prepared in Comparative Example 5 of this application is shown below.

[0024] Figure 8 This is a schematic diagram of the structure of the organic electroluminescent device prepared in Example 3 of this application. Detailed Implementation

[0025] The following description provides specific application scenarios and requirements for this application, intended to enable those skilled in the art to make and use the content of this application. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this application. Therefore, this application is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0026] This application provides an organic electroluminescent device, including a first electrode, a second electrode, and at least one light-emitting layer, wherein the first electrode and the second electrode are disposed opposite to each other, and the light-emitting layer is located between the first electrode and the second electrode.

[0027] The luminescent layer comprises a luminescent host material, and the luminescent host material comprises different deuterated derivatives of the compound shown in Formula 1: In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl.

[0028] The deuterated product is obtained by replacing some or all of the deuteratable hydrogen atoms in the molecular structure of the compound shown in Formula 1 with deuterium. The deuteratable hydrogen atom refers to a hydrogen atom that can be replaced by a deuterium atom. In the compound of Formula 1, the total number of deuteratable hydrogen atoms on the anthracene group is 8; the total number of deuteratable hydrogen atoms on Ar1 is 5; the total number of deuteratable hydrogen atoms on Ar2 is 4; when Ar3 is hydrogen, the total number of deuteratable hydrogen atoms on the carbazole group is 8; when Ar3 is phenyl, the total number of deuteratable hydrogen atoms on Ar3 is 5, and the total number of deuteratable hydrogen atoms on the carbazole group is 7.

[0029] The “different deuterated derivatives of the compound shown in Formula 1” mentioned in this application are defined based on the molecular structural characteristics of the compound, specifically referring to derivatives formed after the parent skeleton is completely identical to that of the compound shown in Formula 1, and some or all of the deuterated hydrogen atoms in the molecular structure are replaced by deuterium atoms; this statement does not represent or limit the preparation method of the deuterated derivatives.

[0030] Specifically, the different deuterated derivatives of the compound shown in Formula 1 described in this application can be prepared by various routes, including but not limited to: directly deuterating the undeuterated compound shown in Formula 1 as a starting material, or by using the stepwise deuteration and coupling process of the intermediate compound described below. That is, the structural definition of "different deuterated derivatives of the compound shown in Formula 1" in this application is intended to cover all products that conform to this structural feature, regardless of their preparation method or process route.

[0031] The differences between the various deuterated compounds are specifically manifested in one or more of the following situations: different compound structures, different deuteration sites, and different numbers of deuterated groups. Among these, the differences in compound structure are reflected in the type of Ar3 and the different linkage sites between Ar3 and the carbazole group. The following are examples of compounds with different structures as shown in Formula 1:

[0032] .

[0033] The luminescent host material may contain only one deuterated derivative of the compound shown in Formula 1, or it may contain different deuterated derivatives of two or more compounds shown in Formula 1. For example, the luminescent host material may contain only one deuterated derivative of the compound shown in Formula 1-1, Formula 1-2, Formula 1-3, Formula 1-4, or Formula 1-5; or it may contain a combination of any two, three, four, or five different deuterated derivatives of the compounds shown in Formulas 1-1 to 1-5.

[0034] The prevailing view is that the higher the degree of deuteration of the luminescent host material, the better the lifespan of organic electroluminescent devices. Ideally, this involves achieving full deuteration of the compound's molecular structure to significantly improve device lifespan. Therefore, many current research directions focus on how to achieve full deuteration modification of compound molecules. In this article, "full deuteration" refers to a state where all deuteratable hydrogen atoms in the compound's molecular structure are replaced by deuterium atoms.

[0035] However, through in-depth research, the inventors of this application unexpectedly discovered that for the compound shown in Formula 1, a significant improvement in device lifetime can be achieved without realizing full deuteration of the molecular structure. Specifically, in different deuterated derivatives of the same compound where Ar3 is hydrogen, the average deuteration rate of Ar1 and anthracene-based deuterated hydrogens is 98.9%-99.5%, and the average deuteration rate of Ar2 and carbazole-based deuterated hydrogens is 98%-99.4%; and / or, in different deuterated derivatives of the same compound where Ar3 is phenyl and the linkage sites are the same, the average deuteration rate of Ar1 and anthracene-based deuterated hydrogens is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3, and carbazole-based deuterated hydrogens is 98%-99.4%. Furthermore, the average deuteration rate of anthracene-based and Ar1 must be greater than the average deuteration rate of carbazole-based, Ar2, and Ar3.

[0036] In this application, the average deuteration rate of the deuterable hydrogen refers to the average deuteration rate of the deuterable hydrogen. The average deuteration rate of the deuterable hydrogen will be explained below using the compounds shown in Formulas 1-2 as examples.

[0037] ;

[0038] In the above formula, d1-d5 represent the deuterated hydrogen sites of the phenyl group corresponding to Ar1, d6-d13 represent the deuterated hydrogen sites of the anthracene group, d14-d17 represent the deuterated hydrogen sites of the phenylene group, d18-d24 represent the deuterated hydrogen sites of the carbazole group, and d25-d29 represent the deuterated hydrogen sites of the phenyl group corresponding to Ar3.

[0039] When deuterating the compounds shown in Equations 1-2, each deuteratable hydrogen may or may not be deuterated. Therefore, the deuteration rate of each deuteratable hydrogen can be calculated, which can represent the degree of deuteration. Since there are many deuteratable hydrogens, each deuteratable hydrogen corresponds to a deuteration rate, which cannot well reflect the overall degree of deuteration of a certain part. Therefore, this application introduces the average deuteration rate of deuteratable hydrogens to represent the degree of deuteration, and the higher the average deuteration rate of deuteratable hydrogens, the higher the degree of deuteration.

[0040] Theoretically, the deuteration rate of any deuteratizable hydrogen can be obtained in the following way: D di %=N Di / N T ×100%, D di % represents the deuteration rate of the deuteratizable hydrogen at the i-th site, N Di N represents the number of deuterated compounds in which the deuteratable hydrogen at the i-th site is replaced by deuterium. T This represents the total number of such compounds (e.g., the compounds shown in Formulas 1-2). The average deuteration rate of the deuterable hydrogens on the Ar1 and anthracene groups can then be obtained as follows: The average deuteration rate of Ar2, Ar3, and the deuteratizable hydrogen atom on the carbazole group can be obtained as follows: .

[0041] In actual quantitative analysis, the average deuteration rate of the deuterated hydrogen can be calculated using proton NMR spectroscopy: A standard sample (such as trimethoxybenzene, 1,4-dioxane, etc.) is dissolved and diluted in a suitable deuteration reagent (such as deuterated DMSO, deuterated chloroform, etc.) to obtain a standard sample solution. The test sample is then dissolved in the standard sample solution, and proton NMR spectroscopy is performed. The molar masses of the standard sample and the test sample are calculated, and then the average deuteration degree is calculated based on the proton NMR spectra.

[0042] In some preferred embodiments, the different deuterated derivatives of the compound represented by Formula 1 are selected from one or more of the following formulas:

[0043] ;

[0044] Wherein, D(n) represents n deuterated hydrogen atoms in anthracene group that are replaced by deuterium, and n≤8; D(m) represents m deuterated hydrogen atoms in the phenyl group corresponding to Ar1 that are replaced by deuterium, and m≤5; D(p) represents p deuterated hydrogen atoms in the phenylene group that are replaced by deuterium, and p≤4; D(q1) represents q1 deuterated hydrogen atoms in the carbazolyl group when Ar3 is hydrogen, and q1≤8; D(q2) represents q2 deuterated hydrogen atoms in the carbazolyl group when Ar3 is phenyl, and q2≤7; D(r) represents r deuterated hydrogen atoms in the phenyl group corresponding to Ar3, and r≤5.

[0045] In the compounds shown in Formula 1, the anthracene group contributes the most to the HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) of the compounds, and its stability is the most critical. Therefore, the degree of deuteration of the anthracene group is required to be higher than that of the carbazole group. In some preferred embodiments, the average deuteration rate of the anthracene group is greater than that of the carbazole group, and the difference is 1%-4%.

[0046] In some preferred embodiments, the light-emitting layer further includes a light-emitting guest material as shown in Formula 2:

[0047] ;

[0048] Wherein, Q1 and Q2 are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophene, substituted or unsubstituted benzocycloalkyl, and the substituent when substituted is selected from deuterium, C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl;

[0049] R is selected from deuterium, C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl; n1 is an integer from 0 to 3; when n1 is 3 and R is a C1-C10 alkyl, the two adjacent alkyl groups form a ring;

[0050] Ar4 and Ar5 are independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C6-C30 arylcycloalkyl, and the substituent when substituted is selected from C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl.

[0051] Unless otherwise specified, "a certain group of Cn-Cm" in this article refers to a certain group having n to m carbon atoms. For example, "an aryl group of C6-C30" refers to an aryl group having 6 to 30 carbon atoms.

[0052] Unless otherwise specified, "aryl" in this document can refer to monocyclic or polycyclic aryl groups; monocyclic aryl groups include, but are not limited to, phenyl and tolyl; polycyclic aryl groups include fused-ring aryl groups, biphenyl-type aryl groups, and polyphenylalanine groups, wherein fused-ring aryl groups include, but are not limited to, naphthyl, anthraceneyl, phenanthryl, and fluorenyl, and biphenyl-type aryl groups include biphenyl; polyphenylalanine groups are structures formed by multiple aromatic rings linked by alkyl groups, such as diphenylmethyl ( ); the “” in the structure of this article "All of these represent connection sites."

[0053] Unless otherwise specified, "heteroaryl" in this document refers to an aryl group containing at least one of B, N, O, P, S, Si, and Se, including but not limited to pyridyl, pyrroloyl, pyrimidinyl, pyridazinyl, furanyl, thiopheneyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, tetrazolyl, pyrazinyl, thiazolyl, triazinyl, tetraazinyl, quinolinyl, isoquinolinyl, indolyl, indoleyl, indoleyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, benzothiazolyl, benzooxazolyl, benzoimidazolyl, benzothiopheneyl, benzofuranyl, dibenzofuranyl, dibenzothiopheneyl, imidazopyridyl, phenanthrolinel, imidazophenanthridyl, naphridinyl, quinazolinyl, quinoxolinyl, etc.

[0054] Unless otherwise specified, "alkyl" in this article may be a straight-chain or branched structure, such as methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl), pentyl (n-pentyl, isopentyl, neopentyl, tert-pentyl), hexyl, heptyl, octyl, nonyl, decyl.

[0055] Unless otherwise specified, "cycloalkyl" in this document refers to a saturated cyclic aliphatic hydrocarbon, which may be a monocycloalkyl or polycycloalkyl; the monocycloalkyl includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, adamantyl, etc.; the polycycloalkyl can be a bridged cycloalkyl, spirocycloalkyl, or a structure formed by multiple monocycloalkyl groups linked by alkyl groups, wherein the bridged cycloalkyl includes, but is not limited to, bicyclic [2.2.1]heptyl ( ), bicyclic [2.2.2] octyl ( ), etc., spirocycloalkyl includes but is not limited to spiro[3,4]octyl, spiro[4,4]nonyl ( )wait.

[0056] In some preferred embodiments, the compound represented by Formula 2 is selected from one or more of the following formulas:

[0057] .

[0058] In some preferred embodiments, the content of the luminescent guest material is 0.1wt%-20wt%, and the content of the luminescent host material is 80wt%-99.9wt%.

[0059] In some embodiments, the organic electroluminescent device further includes at least one functional layer selected from the following: a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a capping layer, wherein each functional layer is a single-layer structure or a multi-layer structure.

[0060] In some specific embodiments, the structure of the organic electroluminescent device may be selected from one of the following:

[0061] (1) An organic electroluminescent device includes an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode stacked in sequence, that is, anode / hole injection layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode. The structure of each device will be expressed in this simplified way below.

[0062] (2) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode.

[0063] (3) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0064] (4) Anode / hole injection layer / second hole transport layer / first hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode.

[0065] (5) Anode / hole injection layer / second hole transport layer / first hole transport layer / light emission layer / first electron transport layer / second electron transport layer / multilayer cathode.

[0066] (6) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0067] (7) Anode / hole injection layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0068] (8) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0069] (9) Anode / hole injection layer / second hole transport layer / first hole transport layer / first light-emitting layer / carrier generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0070] (10) Anode / hole injection layer / hole transport layer / electron blocking layer / light emission layer / electron transport layer / electron injection layer / cathode.

[0071] (11) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0072] (12) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode.

[0073] (13) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode.

[0074] (14) Anode / hole injection layer / hole transport layer / light emission layer / hole blocking layer / electron transport layer / electron injection layer / cathode.

[0075] The light emission direction of the organic electroluminescent device can be either from the anode side or the cathode side. When emitting from the cathode side, the difference from the structure (1)-(14) is that an additional covering layer needs to be added to the cathode side.

[0076] The following describes some specific functional layers in the organic electroluminescent device.

[0077] Substrate:

[0078] The substrate is typically located below the anode and can be made of plastic or glass, and can be rigid or flexible. The substrate has driving units that can drive the corresponding pixels to emit light.

[0079] anode:

[0080] Anodes typically need to meet requirements such as good conductivity, smooth surface, and resistance to cracking. They also have certain requirements for work function, mainly to match the hole injection layer and achieve the hole injection effect.

[0081] When using a top-emitting method (cathode-side light emission), the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm-200 nm. A reflective electrode is placed below the anode (near the substrate end). The reflective electrode is generally made of metal or metal alloy, such as silver, copper, aluminum, gold, or alloys of these metals with other metals. The reflective electrode has high reflectivity, requiring a reflectivity of over 90%, and its thickness is typically between 100 nm and 500 nm, preferably in the range of 80 nm-150 nm.

[0082] When using a bottom-emitting method (substrate-side light emission), the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 1 μm, preferably 50 nm to 200 nm. The anode can be fabricated by forming a thin film from the electrode material using methods such as vapor deposition, sputtering, or coating.

[0083] Hole injection layer:

[0084] The thickness of the hole injection layer can range from 3 nm to 50 nm. The hole injection layer uses a hybrid material of hole dopant and hole transport host material, wherein the mass percentage of hole dopant can be 0.5% to 10%.

[0085] The hole mobility of the hole transport host material is greater than or equal to that of N,N,N',N'-tetraphenylbenzidine diamine (CAS: 164724-35-0). The hole transport host material can be selected from one or more of the following formulas: , , , Wherein: L1-L4, when present individually, are independently selected from single bonds or phenylene. Ar1-Ar4, when present individually, are independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, and the substituents in the case of substitution are selected from C1-C10 alkyl groups. Preferably, Ar1-Ar4, when present individually, are independently selected from phenyl, biphenyl, dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, N-phenylcarbazoyl, benzo[B]naphtho[2,3-D]furanyl, benzo[B]naphtho[1,2-D]furanyl, and benzo[B]naphtho[2,1-D]furanyl. When R1 and R2 are present individually, they are independently selected from substituted or unsubstituted C1-C10 alkyl groups, substituted or unsubstituted C6-C30 aryl groups, and substituted or unsubstituted C3-C30 heteroaryl groups, and the substituents in the case of substitution are selected from C1-C10 alkyl groups. R1 and R2 can also be bonded to form a ring.

[0086] The hole dopant may be selected from organic compounds or metal oxides. For example, the hole dopant may be selected from compounds shown in Formula 3 or Formula 4: Formula 3 Equation 4; In Equation 3, R1-R 15 Each of the R1-R2 is independently selected from fluorine, trifluoromethyl, cyano, and nitro. In Formula 4, each of R1-R2 is independently selected from fluorinated aryl groups.

[0087] As an example, the hole dopant is selected from the following compounds: , .

[0088] Hole transport layer:

[0089] The thickness of the hole transport layer can range from 3 nm to 150 nm. Material selection can refer to the aforementioned hole transport host materials, and will not be repeated here. The hole transport layer can be a single layer or multiple layers. As an example, the hole transport layer may include a first hole transport layer and / or a second hole transport layer.

[0090] Electron blocking layer:

[0091] The electron blocking layer can function as both a hole transport layer and an electron blocking layer. Simultaneously, the higher triplet excitation energy level of the electron blocking layer can confine excitons generated in the emissive layer, thereby improving the luminous efficiency of the device. The thickness is selected from 1-40 nm, preferably 5-20 nm.

[0092] Emissive layer:

[0093] The luminescent layer typically consists of a host material and a dopant material, with the host material comprising a larger proportion than the dopant material. The host material's role is to facilitate the binding of electrons and holes to form electron-hole pairs, i.e., excitons, and to transfer the excitons' energy to the dopant material, thereby emitting light. This requires the host material to possess both considerable electron and hole mobility, as well as a certain triplet energy level.

[0094] To further improve the carrier transport balance of the host material, two or more host materials are used to form the host light-emitting layer through blending or co-evaporation. The guest material determines the emission wavelength and full width at half maximum (FWHM) of the device, i.e., the color of the light. The mass percentage of the guest material in the overall light-emitting layer material can be selected from 1%-3%, 3%-5%, 5%-8%, 8%-10%, 10%-15%, 15%-20%, etc., preferably 1%-3%.

[0095] The thickness of the light-emitting layer can be 10nm-50nm, preferably 15nm-25nm. When a two-layer light-emitting layer structure is used, the first light-emitting layer is in contact with the second light-emitting layer. The thickness of the first light-emitting layer is selected from 5nm-40nm, preferably 10nm-20nm. The thickness of the second light-emitting layer is selected from 1nm-20nm, preferably 3nm-10nm.

[0096] Cavity blocking layer:

[0097] To enhance the balance between hole and electron concentrations, a hole blocking layer is inserted to balance carrier concentration and prevent exciton quenching. Typically, the hole blocking layer is located between the emissive layer and the electron transport layer. The hole blocking layer material must meet conditions such as high stability, good film-forming properties, and a sufficiently high highest molecular occupied orbital (HOO). The thickness is selected from 1-20 nm, preferably 3-10 nm.

[0098] Electron transport layer:

[0099] The electron transport layer can be made of a single compound, such as a triazine compound, or it can be mixed with other metals or metal compounds. For example, it can be mixed with lithium compounds, calcium compounds, magnesium compounds, samarium compounds, ytterbium compounds, etc. More specifically, it can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. The electron transport layer can be a single layer or multiple layers. As an example, the electron transport layer may include a first electron transport layer and / or a second electron transport layer. The thickness is selected from 5-50 nm, preferably 15-40 nm.

[0100] Electron injection layer:

[0101] The electron injection layer can lower the potential barrier for electrons to be injected from the cathode into the organic layer, improving electron injection efficiency and thus optimizing device performance. The material selection for the electron injection layer needs to consider its work function matching with the cathode material. Options include alkali metal compounds (such as LiF), metal oxides (such as Cs₂CO₃), metals (such as Li, Yb), and some small organic molecules or polymers. The thickness is selected from 1-20 nm, preferably 2-10 nm.

[0102] cathode:

[0103] The cathode requires materials with good electrical conductivity and surface smoothness. To improve electron injection capability, materials with low work function are usually selected. Cathode materials can be single-layer, double-layer, or multi-layer cathodes, and are generally made of metals or metal alloys. Thin films can be formed by methods such as vapor deposition and sputtering.

[0104] Overlay:

[0105] When light exits from the cathode side, photons resonate with electrons in the cathode metal, reducing the light extraction efficiency. Adding a capping layer on the side of the cathode furthest from the light-emitting layer can reduce this effect and effectively improve the light efficiency. When adding a capping layer, a capping layer material with high refractive index and low absorption coefficient should be used directly. For example, a material with a refractive index greater than 1.9 and an absorption rate less than 0.01% at a wavelength of 460 nm is preferred, a material with a refractive index greater than 2.0 and an absorption rate less than 0.01% at a wavelength of 460 nm is preferred, and a material with a refractive index greater than 2.1 and an absorption rate less than 0.01% at a wavelength of 460 nm is even more preferred.

[0106] This application also provides the application of the organic electroluminescent device according to the above in display or lighting devices.

[0107] This application also provides a display or lighting device, which includes the organic electroluminescent device described above.

[0108] This application also provides a light-emitting layer material comprising 80wt%-99.9wt% of a light-emitting host material and 0.1wt%-20wt% of a light-emitting guest material; wherein the light-emitting host material comprises different deuterated derivatives of the compound shown in Formula 1: In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl. In different deuterated derivatives of compounds where Ar3 is hydrogen, the average deuteration rate of Ar1 with anthracene is 98.9%-99.5%, and the average deuteration rate of Ar2 with carbazole is 98%-99.4%. And / or, in different deuterated derivatives of compounds where Ar3 is phenyl and the linkage sites are the same, the average deuteration rate of Ar1 with anthracene is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3, and carbazole is 98%-99.4%. Furthermore, the average deuteration rate of anthracene and Ar1 is greater than the average deuteration rate of carbazole, Ar2, and Ar3.

[0109] When the luminescent host material is prepared by directly performing a deuteration reaction using the compound shown in Formula 1 as a raw material, the poor solubility of the compound in Formula 1 usually leads to difficulties in deuteration. In order to improve the deuteration rate, the conventional method is to use a large amount of deuteration reagent to perform multiple deuterations, but this method faces the problem of high deuteration cost and is not suitable for industrial production.

[0110] To address this issue, in some preferred embodiments, the luminescent host material is prepared by a coupling reaction of a deuterated halide and a deuterated borate ester; the deuterated halide is obtained from a first intermediate compound through a first deuteration reaction and a halogenation reaction; the deuterated borate ester is obtained from a second intermediate compound through a second deuteration reaction and a borate esterification reaction; wherein:

[0111] The structural formula of the first intermediate compound is Ar1 is phenyl;

[0112] The structural formula of the deuterated halogenated product is as follows: D(n) represents the n deuterable hydrogen atoms of an anthracene group being replaced by deuterium, and n≤8; Ar1 ' Selected from all or part of deuterated phenyl groups; X1 is selected from chlorine, bromine, or iodine;

[0113] The structural formula of the second intermediate compound is Ar2 is a phenylene; Ar3 is selected from hydrogen or phenyl; X2 is selected from chlorine, bromine or iodine;

[0114] The structural formula of the deuterated borate ester is as follows: or ; BO represents boronic acid ester group; Ar2 ' Selected from all or part of deuterated phenylene groups; D(q1) represents that when Ar3 is hydrogen, q1 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q1≤8; D(q2) represents that when Ar3 is phenyl, q2 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q2≤7; Ar3 'Selected from all or part of deuterated phenyl groups.

[0115] The above preparation method specifically solves the problems of large amount of deuteration reagent, long time consumption, and unsuitability for industrial production caused by poor solubility when directly deuterating the compound shown in Formula 1. Specifically, this application abandons the conventional approach of directly deuterating the poorly soluble final product of Formula 1. Instead, it performs stepwise deuteration on the first and second intermediate compounds, which have better solubility. For the first intermediate compound, a first deuteration reaction is performed. Thanks to the good solubility of the intermediate compound, only a small amount of deuterating reagent is needed to achieve an average deuteration rate of 98.9%-99.5% for the deuterable hydrogen atoms. The deuterated product is then subjected to a halogenation reaction to obtain a deuterated halide. For the second intermediate compound, a second deuteration reaction is performed. Again, taking advantage of the solubility of the intermediate compound, only a small amount of deuterating reagent is needed to achieve an average deuteration rate of 98%-99.4% for the deuterable hydrogen atoms of Ar2, Ar3 and carbazole groups. The deuterated product is then subjected to a borate esterification reaction to obtain a deuterated borate ester. Finally, the two pre-deuterated intermediate compound products are coupled together to directly obtain the target host material.

[0116] Compared to the conventional method of deuterating the final product multiple times with a large amount of reagents, this method significantly reduces the consumption of deuteration reagents, shortens the deuteration reaction time, and significantly reduces production costs, making it more in line with the requirements of large-scale industrial production.

[0117] Furthermore, it is generally believed in the art that the higher the degree of deuteration, the better the device lifespan. Based on this view, conventional processes attempt to achieve a uniformly high deuteration rate for each group of the compound through multiple deuterations with high-dose reagents. However, the inventors of this application unexpectedly discovered that a reasonable difference in the deuteration rate of each group is more conducive to improving the lifespan of organic electroluminescent devices. The stepwise deuteration process of this application can precisely achieve this differentiated deuteration rate distribution. Due to the differences in the structural characteristics and solubility of the first and second intermediate compounds, their deuteration reaction efficiencies are also different. After functional group transformation and coupling, the average deuteration rate of anthracene and Ar1 is finally greater than that of carbazole, Ar2, and Ar3. This process does not require the introduction of additional complex control methods; performance optimization can be achieved simply through process path design, taking into account both production convenience and device application effects.

[0118] In some preferred embodiments, the method for preparing the luminescent host material includes the following steps:

[0119] S1: The first intermediate compound undergoes a first deuteration reaction to obtain a first deuterated compound; the first deuterated compound is then subjected to a halogenation reaction to obtain a deuterated halide.

[0120] S2: The second intermediate compound undergoes a second deuteration reaction to obtain a second deuterated compound; the second deuterated compound is then subjected to a borate esterification reaction to obtain a deuterated borate ester.

[0121] S3: The deuterated halide and the deuterated borate ester are coupled to obtain the deuterated composition.

[0122] In step S1, the structural formula of the first intermediate compound is as follows: Ar1 is phenyl. The structural formula of the deuterated halide is: D(n) represents the n deuterable hydrogen atoms of an anthracene group being replaced by deuterium, and n≤8; Ar1 ' X1 is selected from all or part of deuterated phenyl groups; X1 is selected from chlorine, bromine or iodine.

[0123] In step S2, the structural formula of the second intermediate compound is as follows: Ar2 is a phenylene oxide; Ar3 is selected from hydrogen or phenyl; X2 is selected from chlorine, bromine, or iodine. The structural formula of the deuterated borate ester is as follows: or ; BO represents boronic acid ester group; Ar2 ' Selected from all or part of deuterated phenylene groups; D(q1) represents that when Ar3 is hydrogen, q1 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q1≤8; D(q2) represents that when Ar3 is phenyl, q2 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q2≤7; Ar3 ' Selected from all or part of deuterated phenyl groups.

[0124] In some preferred embodiments, in step S1, the first deuteration reaction is carried out in the presence of a first catalyst, and the first catalyst includes at least one selected from protic acids, Lewis acids, and polymerically bonded sulfonic acids. As an example, the protic acid may be selected from trifluoroacetic acid, trifluoromethanesulfonic acid, perfluorobutylsulfonic acid, etc. As an example, the Lewis acid may be selected from aluminum chloride, zinc chloride, molybdenum chloride, etc.

[0125] In some preferred embodiments, in step S1, the first deuteration reaction is carried out in the presence of a first catalyst, and the mass of the first catalyst is 3%-20% of the mass of the first intermediate compound.

[0126] In some preferred embodiments, in step S1, the first deuteration reaction uses a first deuteration reagent, and the first deuteration reagent includes deuterated benzene and / or deuterated water.

[0127] In some preferred embodiments, in step S1, the first deuteration reaction uses a first deuteration reagent, and the volume ratio (also known as the volume-to-weight ratio) of the first deuteration reagent to the first intermediate compound is (10~20) mL:1 g. Since the first intermediate compound has good solubility, only a small amount of the first deuteration reagent is needed to achieve a high average deuteration rate.

[0128] In some preferred embodiments, in step S1, the first deuteration reaction uses a first deuteration reagent, the reaction temperature of the first deuteration reaction is the reflux temperature of the corresponding first deuteration reagent, and the reaction time is 1-5 days.

[0129] In some preferred embodiments, in step S1, the method of subjecting the first deuterated compound to a halogenation reaction includes: subjecting the first deuterated compound to a bromination reaction at a reaction temperature of 0°C-50°C for a reaction time of 1 hour-24 hours.

[0130] More preferably, the method for causing the first deuterated compound to undergo a bromination reaction includes: reacting the first deuterated compound with N-bromosuccinimide, wherein the solvent used is selected from at least one of N,N-dimethylformamide, toluene, and chlorobenzene.

[0131] In some preferred embodiments, in step S2, the second deuteration reaction is carried out in the presence of a second catalyst, and the second catalyst includes at least one selected from protic acids, Lewis acids, and polymerically bonded sulfonic acids. As an example, the protic acid may be selected from trifluoroacetic acid, trifluoromethanesulfonic acid, perfluorobutylsulfonic acid, etc. As an example, the Lewis acid may be selected from aluminum chloride, zinc chloride, molybdenum chloride, etc.

[0132] In some preferred embodiments, in step S2, the second deuteration reaction is carried out in the presence of a second catalyst, and the mass of the second catalyst is 3%-20% of the mass of the second intermediate compound.

[0133] In some preferred embodiments, in step S2, the second deuteration reaction employs a second deuteration reagent, and the second deuteration reagent includes deuterated benzene and / or deuterated water.

[0134] In some preferred embodiments, in step S2, the second deuteration reaction uses a second deuteration reagent, and the volume ratio of the second deuteration reagent to the mass ratio of the second intermediate compound is (10-20) mL:1 g.

[0135] In some preferred embodiments, in step S2, the second deuteration reaction uses a second deuteration reagent, and the reaction temperature of the second deuteration reaction is the reflux temperature of the corresponding second deuteration reagent, and the reaction time is 1-5 days.

[0136] In some preferred embodiments, in step S2, the method of subjecting the second deuterated compound to a borate ester reaction includes: reacting the second deuterated compound with a borate ester compound at a reaction temperature of 0°C-100°C for a reaction time of 1 hour-24 hours.

[0137] More preferably, the borate ester compound includes pinacol diboronate.

[0138] In some preferred embodiments, during the coupling reaction in step S3, the catalyst is selected from platinum compounds and palladium compounds, such as Pd(dppf)Cl2, Pd2(dba)3, palladium acetate, etc., and the auxiliary ligand is selected from phosphine ligands, such as 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl, etc. The reaction system is alkaline, and K2CO3 or Cs2CO3 can be used to adjust the pH value of the system. The solvent used is selected from at least one of benzene, toluene, xylene, and chlorobenzene. The reaction temperature is from room temperature to the boiling point of the solvent, and the reaction time is 1 hour to 24 hours.

[0139] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional methods and conditions, or conditions recommended by the manufacturer, or the product instructions shall be followed.

[0140] The raw materials and solvents used in the following examples were purchased from Sinopharm, and some commonly used OLED intermediate compounds were purchased from domestic OLED intermediate manufacturers; NMR data were measured using a Varian 400-MR NMR spectrometer.

[0141] Example 1

[0142] The synthesis route of the luminescent host material in this embodiment is as follows:

[0143] ;

[0144] The specific preparation method is as follows:

[0145] 1) Preparation of compound 1-1:

[0146] In a clean 1000 mL three-necked flask, compounds 1-A (51.4 g, 200 mmol), 1-B (24.4 g, 200 mmol), K₂CO₃ (55.2 g, 400 mmol), Pd₂(dba)₃ (1.83 g, 2 mmol), and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (S-Phos, 1.64 g, 4 mmol) were added sequentially. Then, 600 mL of toluene, 200 mL of ethanol, and 100 mL of water were added. The system was purged with nitrogen three times. The reaction mixture was heated to 95 °C and stirred under reflux for 16 hours. The reaction was monitored for completeness by TLC. The reaction solution was cooled to room temperature and separated. The organic phase was subjected to rapid silica gel column chromatography (eluted with toluene). The residue was concentrated to dryness, crystallized from toluene and n-hexane, and filtered to give 44.8 g of a white solid, compound 1-1, in 88% yield.

[0147] 2) Preparation of compounds 1-2:

[0148] In a clean 1000 mL three-necked flask, compound 1-1 (43.2 g, 170 mmol), perfluorobutylsulfonic acid (5.1 g, 17 mmol), and 500 mL of deuterium benzene were added. The system was purged with nitrogen three times, and the reaction was heated to reflux and stirred for 4 days. The reaction solution was cooled to room temperature, and the deuterium benzene was recovered by concentration. 500 mL of dichloromethane and 200 mL of 10% sodium carbonate solution were added, and the mixture was stirred for half an hour. The mixture was separated. The solution was washed once with water and dried. The organic phase was passed through a silica gel column and eluted with dichloromethane. The solvent was removed by concentration, and the solid was washed with 200 mL of ethanol at room temperature, filtered, and dried to give 44.2 g of compound 1-2, with a yield of 97%.

[0149] 3) Preparation of compounds 1-3:

[0150] Compound 1-2 (42.9 g, 160 mmol), N-succinimide bromide (NBS, 31.5 g, 176 mmol), and DMF (400 mL) were added to a clean 1000 mL three-necked flask. The mixture was gradually heated to 50 °C and stirred for 2 hours. TLC was used to monitor the complete conversion of the reactants. The reaction mixture was slowly added dropwise to 500 mL of water and stirred for 1 hour. The mixture was then filtered. The filter cake was washed with 100 mL of ethanol and then refluxed with 100 mL of n-hexane for 2 hours. The mixture was cooled to room temperature and filtered to give 49.9 g of solid compound 1-3, with a yield of 90%.

[0151] 4) Preparation of compounds 1-4:

[0152] In a clean 1000 mL reaction flask, compound 1-C (33.4 g, 200 mmol), compound 1-D (40.2 g, 210 mmol), sodium tert-butoxide (38.4 g, 400 mmol), Pd2(dba)3 (1.83 g, 2 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.16 g, 4 mmol) were added sequentially, followed by 600 mL of xylene. The system was purged with nitrogen three times. The reaction was heated to 140 °C and stirred under reflux for 16 hours. The reaction was monitored for completeness by TLC. The reaction solution was cooled to room temperature, quenched with water, and extracted. The organic phase was subjected to rapid silica gel column chromatography (eluted with toluene). The concentrate was concentrated, washed with ethanol under reflux, cooled, and filtered to give 47.8 g of white solid compound 1-4, with a yield of 86%.

[0153] 5) Preparation of compounds 1-5:

[0154] In a clean 1000 mL three-necked flask, compounds 1-4 (47.2 g, 170 mmol), trifluoromethanesulfonic acid (25.5 g, 170 mmol), and 500 mL of deuterium benzene were added. The system was purged with nitrogen three times, and the reaction was heated to reflux and stirred for 2 days. The reaction solution was cooled to room temperature, and the deuterium benzene was recovered by concentration. 500 mL of toluene and 300 mL of 10% sodium carbonate solution were added, and the mixture was stirred for half an hour. The mixture was separated. The solution was washed once with water and dried. The organic phase was passed through a silica gel column and eluted with toluene. The solvent was removed by concentration, and the solid was washed with ethanol under reflux, cooled, filtered, and dried to give 45.8 g of compounds 1-5, with a yield of 93%.

[0155] 6) Preparation of compounds 1-6:

[0156] In a clean 1000 mL three-necked flask, compounds 1-5 (44.9 g, 155 mmol), pinacol diborate (47.2 g, 186 mmol), KOAc (30.4 g, 310 mmol), Pd2(dba)3 (1.46 g, 1.6 mmol), and S-Phos (1.31 g, 3.2 mmol) were added sequentially, followed by 600 mL of toluene. The system was purged with nitrogen three times. The reaction was heated to 100 °C and stirred for 16 hours. The reaction was monitored for completeness by TLC. The reaction solution was cooled to room temperature, quenched with water, and extracted. The organic phase was subjected to rapid silica gel column chromatography (eluted with toluene). The extract was concentrated, crystallized from toluene and n-hexane, and filtered to give 54.4 g of white solid compound 1-6, with a yield of 92%.

[0157] 7) Preparation of the luminescent host material BH1:

[0158] In a clean 2000 mL three-necked flask, compounds 1-3 (48.5 g, 140 mmol), 1-6 (53.4 g, 140 mmol), K₂CO₃ (38.6 g, 280 mmol), Pd₂(dba)₃ (1.28 g, 1.4 mmol), S-Phos (1.15 g, 2.8 mmol), 800 mL toluene, 400 mL ethanol, and 200 mL water were added. The system was purged with nitrogen three times. The reaction mixture was heated to 95 °C and stirred under reflux for 16 hours. The reaction was confirmed to be complete by TLC. After cooling to room temperature, a large amount of solid precipitated. The solid was filtered, washed with ethanol, and then dissolved in toluene by heating. The temperature was lowered to 80 °C, and the solution was rapidly precipitated by silica gel column chromatography. After washing with hot toluene, the solution was concentrated to a certain volume and recrystallized with ethanol. The solution was cooled, filtered, and recrystallized again. After filtration, the solution was dried under vacuum to obtain 54.7 g of white solid luminescent host material BH₁, with a yield of 75%.

[0159] The product was purified by vacuum sublimation at a vacuum level of 3 × 10⁻⁶. -5 Pa, with a sublimation temperature of 245℃.

[0160] ¹H NMR assay: Weigh 14.0 mg of mesitylene and dissolve it in 1207.8 mg of DMSO-D6 to prepare a standard sample. Mix 9.90 mg of the test sample and 43.97 mg of the standard sample, dissolve them in DMSO-D6, and perform the assay. The NMR spectrum is shown below. Figure 1 As shown.

[0161] According to NMR analysis, the shift peaks at 8.31 ppm, 7.92 ppm, 7.77 ppm, 7.68 ppm, 7.54 ppm, 7.52 ppm, and 7.36 ppm are attributed to hydrogen atoms on the phenylene group and carbazole group, while the shift peaks at 7.81 ppm, 7.69 ppm, 7.63 ppm, 7.50 ppm, and 7.48 ppm are attributed to hydrogen atoms on the anthracene group and phenyl group. The hydrogen integral of the anthracene group and phenyl group is 0.39, and the hydrogen integral of the carbazole group and phenylene group is 0.54. Calculations show that the average deuteration rate of the anthracene group and phenyl group (Ar1) is 99.49%, and the average deuteration rate of the carbazole group and phenylene group (Ar2) is 99.34%.

[0162] The specific calculation method is as follows:

[0163] The molar mass of the standard sample in the test sample was calculated based on the weight, dilution factor, and molecular weight of the standard sample: Molar mass of trimethoxybenzene = 43.97 × (14.0 ÷ 1207.8) ÷ 168.2 = 0.00303 mmol.

[0164] The molar amount of the test sample is calculated as: 9.99 ÷ 520.8 = 0.0192 mmol.

[0165] The baseline reference data for NMR hydrogen integrals were determined as follows: 3 hydrogen atoms correspond to 6.09 ppm in the standard sample, with a hydrogen integral of 3; the non-deuterated phenyl and anthracene groups in the test sample contain 13 hydrogen atoms, while the non-deuterated phenylene and carbazole groups contain 12 hydrogen atoms.

[0166] The theoretical hydrogen integral values ​​of each group in the undeuterated state of the test sample were calculated as follows: The theoretical hydrogen integral of the undeuterated phenylene and carbazole groups is: 0.0192 ÷ 0.00303 × 12 = 76.04; The theoretical hydrogen integral of the undeuterated anthracene and phenyl groups is: 0.0192 ÷ 0.00303 × 13 = 82.38.

[0167] Actual NMR hydrogen integral results: The standard sample has a hydrogen integral of 3 for trimethoxybenzene, the tested samples have an actual hydrogen integral of 0.54 for phenylene and carbazole groups, and an anthracene and phenyl groups have an actual hydrogen integral of 0.39.

[0168] Calculate the average deuteration rate of each group: the average deuteration rate of anthracene group and phenyl group (Ar1) = 1 - 0.39 ÷ 76.04 = 99.49%; the average deuteration rate of carbazolyl group and phenylene group (Ar2) = 1 - 0.54 ÷ 82.38 = 99.34%.

[0169] Comparative Example 1

[0170] The synthesis route of the luminescent host material in this comparative example is as follows: ;

[0171] The specific preparation method is as follows:

[0172] The preparation steps were basically the same as in Example 1, except that compound 1-1 was not subjected to a first deuteration reaction, and compounds 1-4 were not subjected to a second deuteration reaction. Instead, compound BH3 underwent two deuteration reactions. Because BH3 has poor solubility, the amount of deuterated benzene used in both deuteration reactions was significantly higher than that used in the corresponding steps of Example 1: in the first deuteration reaction, the volume-to-weight ratio of deuterated benzene to the deuterated raw material was 18.5:1 (mL / g); in the second deuteration reaction, the volume-to-weight ratio was 21.5:1 (mL / g). Other conditions for the two deuteration reactions can be found in Example 1. The yields of the two deuteration reactions were 87% and 82%, respectively.

[0173] ¹H NMR assay: Weigh 14.0 mg of trimethoxybenzene and dissolve it in 1207.8 mg of DMSO-D6 to prepare a standard sample for later use. Mix 11.8 mg of the test sample and 44.96 mg of the standard sample, dissolve them in DMSO-D6, and perform the assay. The NMR spectrum is shown below. Figure 2 As shown.

[0174] like Figure 2 As shown, according to NMR analysis, the shift peaks at 8.32 ppm, 7.92 ppm, 7.78 ppm, 7.68 ppm, 7.54 ppm, 7.53 ppm, and 7.36 ppm are attributed to hydrogen atoms on the phenylene group and carbazole group, while the shift peaks at 7.81 ppm, 7.69 ppm, 7.63 ppm, 7.51 ppm, and 7.48 ppm are attributed to hydrogen atoms on the anthracene group and phenyl group. The hydrogen integral for the anthracene group and phenyl group is 1.93, and the hydrogen integral for the carbazole group and phenylene group is 4.10. Calculations show that the average deuteration rate of the anthracene group and phenyl group (Ar1) is 97.80%, and the average deuteration rate of the carbazole group and phenylene group (Ar2) is 95.68%. The calculation method is the same as in Example 1.

[0175] Comparative Example 2

[0176] The synthesis route of the luminescent host material in this comparative example is as follows:

[0177] ;

[0178] The specific preparation method is as follows:

[0179] The steps are basically the same as in Example 1, except that compounds 1-4 are not subjected to a second deuteration reaction, and the conditions for the first deuteration reaction are the same as those for the first deuteration reaction in Example 1.

[0180] The NMR testing method can be found in Comparative Example 1, and the NMR spectrum is as follows: Figure 3 As shown. Direct comparison using the internal hydrogen standards of carbazole and phenylene groups showed that neither was deuterated, with a hydrogen integral of 12.0. The theoretical integral for the undeuterated anthraquinone and phenyl groups is 12.0 × 13 ÷ 12 = 13.0, while the actual hydrogen integral for anthraquinone and phenyl groups is 0.08. Therefore, the average deuteration rate of the deuteratizable hydrogens in anthraquinone and phenyl groups is calculated to be 1 - 0.08 ÷ 13.0 = 99.38%.

[0181] Comparative Example 3

[0182] The luminescent host material in this comparative example is compound BH3 prepared in Comparative Example 1, and its NMR spectrum is shown below. Figure 4 As shown.

[0183] Example 2

[0184] The synthesis route of the luminescent host material in this embodiment is as follows:

[0185] ;

[0186] The preparation method can be found in Example 1:

[0187] 1) The preparation of compound 1-1 is the same as in Example 1;

[0188] 2) The preparation of compounds 1-2 is the same as in Example 1;

[0189] 3) The preparation of compounds 1-3 is the same as in Example 1;

[0190] 4) Preparation of compound 4-4: Following the preparation method of compound 1-4 in Example 1, compound 1-C was replaced with compound 4-C to obtain compound 4-4;

[0191] 5) Preparation of compound 4-5: Following the preparation method of compound 1-5 in Example 1, compound 1-4 was replaced with compound 4-4 to obtain compound 4-5;

[0192] 6) Preparation of compounds 4-6: Following the preparation method of compounds 1-6 in Example 1, compounds 1-5 were replaced with compounds 4-5 to obtain compounds 4-6;

[0193] 7) Preparation of luminescent host material BH4: Referring to the preparation method of luminescent host material BH1 in Example 1, compounds 1-6 were replaced with compounds 4-6 to obtain luminescent host material BH4 with a yield of 82.1%.

[0194] ¹H NMR assay: 14.0 mg of trimethoxybenzene was dissolved in 1207.8 mg of DMSO-D6 to prepare a standard sample. 8.33 mg of the test sample and 36.43 mg of the standard sample were mixed and dissolved in DMSO-D6 for testing. The NMR spectrum is shown below. Figure 5 As shown.

[0195] like Figure 5 As shown, according to NMR analysis, the shift peaks at 8.40 ppm, 8.35 ppm, 8.00 ppm, 7.85 ppm, 7.79 ppm, 7.69 ppm (top), 7.65 ppm, 7.55 ppm, 7.53 ppm, 7.39 ppm, and 7.38 ppm are attributed to hydrogen atoms on the phenylene, carbazolyl, and phenyl groups, respectively; the shift peaks at 7.83 ppm, 7.69 ppm (bottom), 7.63 ppm, 7.51 ppm, and 7.48 ppm are attributed to hydrogen atoms on the anthracene and phenyl groups. The hydrogen integral of the anthracene and phenyl (Ar1) group is 0.74, and the hydrogen integral of the carbazolyl, phenylene (Ar2), and phenyl (Ar3) group is 1.44. Calculations show that the average deuteration rate of the deuterable hydrogen atoms in the anthracene and phenyl (Ar1) group is 98.97%, and the average deuteration rate of the deuterable hydrogen atoms in the carbazolyl, phenylene (Ar2), and phenyl (Ar3) group is 98.37%. The calculation method is the same as in Example 1.

[0196] Comparative Example 4

[0197] The synthesis route of the luminescent host material in this comparative example is as follows:

[0198] ;

[0199] The specific preparation method is as follows:

[0200] The procedure was essentially the same as in Example 2, except that compound 4-4 was not deuterated; instead, compound 4-7' underwent a second deuteration reaction. Because compound 4-7' has poor solubility, the amount of deuterated benzene used in both deuteration reactions was significantly increased. Other conditions for both deuteration reactions were the same as those for the first and second deuteration reactions in Example 1. The yields for the two deuteration reactions were 85% and 80%, respectively.

[0201] like Figure 6 As shown, based on NMR testing and calculations, the average deuteration rate of anthracene and phenyl deuterated hydrogens is 99.07%, while the average deuteration rate of carbazole, phenylene and phenyl deuterated hydrogens is 97.70%.

[0202] Comparative Example 5

[0203] The synthetic route for the deuterated composition in this comparative example is as follows:

[0204] ;

[0205] The specific preparation method is as follows:

[0206] The steps are basically the same as in Example 2, except that compound 4-4 is not subjected to a second deuteration reaction, and the conditions for the first deuteration reaction are the same as those for the first deuteration reaction in Example 1.

[0207] The NMR testing method can be found in Comparative Example 1, and the NMR spectrum is as follows: Figure 7 As shown. Comparison using internal standards of hydrogen for carbazole, phenylene, and phenyl groups showed that none of them were deuterated, with a hydrogen integral of 16.53. The theoretical integral for the undeuterated anthraquinone and phenyl (Ar1) combination is 16.53 × 13 ÷ 16 = 13.43, while the actual hydrogen integral for the anthraquinone and phenyl (Ar1) combination is 0.10. Therefore, the average deuteration rate of the deuteratizable hydrogens in the anthraquinone and phenyl (Ar1) combination is calculated to be 1 - 0.10 ÷ 13.43 = 99.26%.

[0208] Example 3

[0209] refer to Figure 8 This embodiment provides an organic electroluminescent device, the preparation method of which includes the following steps:

[0210] (1) A hole injection layer 103 is formed by vapor deposition of a mixture of compound 1 and compound 2 on the surface of the reflective anode 102 on the substrate 101, with a mass ratio of 1:99 and a thickness of 10 nm.

[0211] (2) Compound 2 is deposited on the surface of hole injection layer 103 to form a first hole transport layer 104 with a thickness of 100 nm.

[0212] (3) Compound 3 is vapor-deposited on the surface of the first hole transport layer 104 to form a second hole transport layer 105 with a thickness of 5 nm.

[0213] (4) The light-emitting host material compound 4 and the light-emitting guest material compound 5 are co-deposited at a mass ratio of 99:1 to form a light-emitting layer 106 with a thickness of 25nm on the surface of the second hole transport layer 105.

[0214] (5) A hole blocking layer 107 with a thickness of 5 nm is formed by evaporating compound 6 on the surface of the light-emitting layer 106, and then an electron transport layer 108 with a thickness of 30 nm is formed by evaporating compound 7 and LiQ with a mass ratio of 4:6.

[0215] (6) A 5 nm electron injection layer 109 is formed by evaporating ytterbium (Yb) on the surface of electron transport layer 108. Magnesium (Mg) and silver (Ag) are mixed and deposited on the surface of electron injection layer 109 at a evaporation rate of 1:9 to form a second electrode with a thickness of 14 nm as cathode 110.

[0216] (7) A 60 nm thick capping layer 111 is formed by vapor deposition of compound 8 on the surface of cathode 110.

[0217] The compounds involved in the above preparation process are shown in Table 1.

[0218] Table 1. Structural Formulas of Compounds

[0219]

[0220] Comparative Example 6

[0221] This comparative example provides an organic electroluminescent device, which differs from Example 3 only in that the light-emitting host material BH1 prepared in Example 1 is replaced with the light-emitting host material BH1 prepared in Comparative Example 1.

[0222] Comparative Example 7

[0223] This comparative example provides an organic electroluminescent device, which differs from Example 3 only in that the light-emitting host material BH1 prepared in Example 1 is replaced with the light-emitting host material BH2 prepared in Comparative Example 2.

[0224] Comparative Example 8

[0225] This comparative example provides an organic electroluminescent device, which differs from Example 3 only in that the light-emitting host material BH1 prepared in Example 1 is replaced with the light-emitting host material BH3 of Comparative Example 3.

[0226] Example 4

[0227] This embodiment provides an organic electroluminescent device, which differs from Embodiment 3 only in that the light-emitting host material BH1 prepared in Embodiment 1 is replaced with the light-emitting host material BH4 prepared in Embodiment 2.

[0228] Comparative Example 9

[0229] This comparative example provides an organic electroluminescent device, which differs from Example 4 only in that the light-emitting host material BH4 prepared in Example 2 is replaced with the light-emitting host material BH4 prepared in Comparative Example 4.

[0230] Comparative Example 10

[0231] This comparative example provides an organic electroluminescent device, which differs from Example 4 only in that the light-emitting host material BH4 prepared in Example 2 is replaced with the light-emitting host material BH5 prepared in Comparative Example 5.

[0232] Device lifetime testing

[0233] The organic electroluminescent devices prepared in the examples and comparative examples were tested using a Fostar lifetime measurement system equipped with a power supply and a photodiode as detection units. The test conditions were a constant current of 50 mA / cm². 2 The device lifetime under dark conditions was obtained, and the test results are shown in Table 2. LT95 refers to the time (in hours) required for the brightness to decay from the initial brightness to 95%. The longer the device lifetime, the more durable the device.

[0234] Table 2 Lifetime Test Results

[0235]

[0236] As shown in Table 2, this application can prepare luminescent host materials with an average deuteration rate of 98.9%-99.5% for anthracene-based and Ar1, and an average deuteration rate of 98%-99.4% for carbazole-based, Ar2, and Ar3. Furthermore, the average deuteration rate of anthracene-based and Ar1 is higher than that of carbazole-based, Ar2, and Ar3. When using this luminescent host material to prepare organic electroluminescent devices, the device lifetime can be significantly improved, with an LT95 lifetime exceeding 96 hours, far superior to the comparative examples with insufficient deuteration rates.

[0237] Furthermore, this application utilizes a stepwise deuteration method to prepare the luminescent host material. This method not only significantly improves the degree of deuteration but also simplifies and controls the synthesis process, significantly reducing deuteration reagent consumption and production costs, making it particularly suitable for large-scale industrial production. The core reason for this is that the solubility of the intermediate compound is far superior to that of the final product. Therefore, compared to directly deuterating the final product, deuterating the intermediate significantly saves deuteration reagents, resulting in superior economic efficiency.

[0238] For example, compared with Comparative Example 1, the degree of deuteration in Example 1 is significantly higher, and the stepwise deuteration scheme of this application has a significant advantage in terms of reagent usage. Specifically, in Example 1, the volume-to-weight ratio of deuterated benzene to the deuterated raw material (compound 1-1) used in the preparation of compounds 1-2 (first deuteration reaction) is 11.57:1 (mL / g); the volume-to-weight ratio of deuterated benzene to the deuterated raw material (compound 1-4) used in the preparation of compounds 1-5 (second deuteration reaction) is 10.59:1 (mL / g). In Comparative Example 1, when the final product is deuterated twice, the corresponding volume-to-weight ratio of deuterated benzene to the deuterated product is 18.5:1 (mL / g) and 21.5:1 (mL / g), respectively. The amounts of deuteration used in Comparative Example 1 for the two deuterations are 1.6 times and 2 times that used in Example 1 for the two deuterations. Therefore, this application significantly reduces the amount of deuterated benzene used, resulting in better economic efficiency. Similarly, the target product in Example 2 also has poor solubility, while its intermediate compound has good solubility. Using the intermediate compound for deuteration can further save on deuteration reagents.

[0239] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. An organic electroluminescent device, characterized in that, include: First electrode; The second electrode is disposed opposite to the first electrode; At least one light-emitting layer is located between the first electrode and the second electrode; The light-emitting layer comprises a light-emitting host material, and the light-emitting host material comprises different deuterated derivatives of the compound shown in Formula 1: ； In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl; Among the different deuterated derivatives of compounds in which Ar3 is hydrogen, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2 with carbazole group is 98%-99.4%. And / or, in different deuterated derivatives of compounds in which Ar3 is phenyl and has the same linkage site, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3 with carbazole group is 98%-99.4%; Meanwhile, the average deuteration rates of anthracene and Ar1 were greater than those of carbazolyl, Ar2, and Ar3.

2. The organic electroluminescent device according to claim 1, characterized in that, Different deuterated derivatives of the compound shown in Formula 1 are selected from one or more of the following formulas: ； in: D(n) represents the n deuterable hydrogen atoms of an anthracene group being replaced by deuterium, and n≤8; D(m) represents the m deuterable hydrogen atoms in the phenyl group corresponding to Ar1 that are replaced by deuterium, and m≤5; D(p) represents the p deuterable hydrogen atoms of a phenylene group being replaced by deuterium, and p≤4; D(q1) represents the q1 deuterable hydrogen atoms in the carbazolyl group when Ar3 is hydrogen, and q1≤8; D(q2) represents that when Ar3 is phenyl, q2 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q2≤7; D(r) represents the r deuterable hydrogen atoms in the phenyl group corresponding to Ar3 being replaced by deuterium, and r≤5.

3. The organic electroluminescent device according to claim 1, characterized in that, The average deuteration rate of the anthracene group is greater than that of the carbazole group, and the difference is 1%-4%.

4. The organic electroluminescent device according to claim 1, characterized in that, The light-emitting layer also includes a light-emitting object material as shown in Formula 2: ； Wherein, Q1 and Q2 are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophene, substituted or unsubstituted benzocycloalkyl, and the substituent when substituted is selected from deuterium, C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl; R is selected from deuterium, C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl; n1 is an integer from 0 to 3; when n1 is 3 and R is a C1-C10 alkyl, the two adjacent alkyl groups form a ring; Ar4 and Ar5 are independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C6-C30 arylcycloalkyl, and the substituent when substituted is selected from C6-C30 aryl, C6-C30 heteroaryl, C1-C10 alkyl or C3-C10 cycloalkyl.

5. The organic electroluminescent device according to claim 4, characterized in that, The content of the luminescent guest material is 0.1wt%-20wt%, and the content of the luminescent host material is 80wt%-99.9wt%.

6. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The organic electroluminescent device further includes at least one functional layer selected from the following: hole injection layer, hole transport layer, electron blocking layer, hole blocking layer, electron transport layer, electron injection layer, and capping layer, and each functional layer is a single-layer structure or a multi-layer structure.

7. The application of an organic electroluminescent device according to any one of claims 1 to 6 in a display or lighting device.

8. A display or lighting device, characterized in that, The display or lighting device includes any one of the organic electroluminescent devices described in 1 to 6.

9. A light-emitting layer material, characterized in that, It contains 80wt%-99.9wt% of luminescent host material and 0.1wt%-20wt% of luminescent guest material; The luminescent host material comprises different deuterated derivatives of the compound shown in Formula 1: ; In Formula 1, Ar1 is phenyl, Ar2 is phenylene, and Ar3 is selected from hydrogen or phenyl; Among the different deuterated derivatives of compounds in which Ar3 is hydrogen, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2 with carbazole group is 98%-99.4%. And / or, in different deuterated derivatives of compounds in which Ar3 is phenyl and has the same linkage site, the average deuteration rate of Ar1 with anthracene group is 98.9%-99.5%, and the average deuteration rate of Ar2, Ar3 with carbazole group is 98%-99.4%; Meanwhile, the average deuteration rates of anthracene and Ar1 were greater than those of carbazolyl, Ar2, and Ar3.

10. The light-emitting layer material according to claim 9, characterized in that, The luminescent host material is prepared by a coupling reaction of a deuterated halide and a deuterated borate ester; the deuterated halide is obtained by sequentially performing a first deuteration reaction and a halogenation reaction on a first intermediate compound; the deuterated borate ester is obtained by sequentially performing a second deuteration reaction and a borate esterification reaction on a second intermediate compound; wherein: The structural formula of the first intermediate compound is Ar1 is phenyl; The structural formula of the deuterated halogenated product is as follows: D(n) represents the n deuterable hydrogen atoms of an anthracene group being replaced by deuterium, and n≤8; Ar1 ' Selected from all or part of deuterated phenyl groups; X1 is selected from chlorine, bromine, or iodine; The structural formula of the second intermediate compound is Ar2 is a phenylene; Ar3 is selected from hydrogen or phenyl; X2 is selected from chlorine, bromine or iodine; The structural formula of the deuterated borate ester is as follows: or ; BO represents boronic acid ester group; Ar2 ' Selected from all or part of deuterated phenylene groups; D(q1) represents that when Ar3 is hydrogen, q1 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q1≤8; D(q2) represents that when Ar3 is phenyl, q2 deuterable hydrogens in the carbazolyl group are replaced by deuterium, and q2≤7; Ar3 ' Selected from all or part of deuterated phenyl groups.

11. The light-emitting layer material according to claim 10, characterized in that, The first deuteration reaction satisfies at least one of the following conditions: (a) The process is carried out in the presence of a first catalyst, wherein the first catalyst comprises at least one of a protic acid, a Lewis acid, and a polymerically bonded sulfonic acid; (b) The process is carried out in the presence of a first catalyst, wherein the mass of the first catalyst is 3%-20% of the mass of the first intermediate compound; (c) A first deuterated reagent is used, wherein the first deuterated reagent comprises deuterated benzene and / or deuterated water; (d) A first deuterated reagent is used, and the ratio of the volume of the first deuterated reagent to the mass of the first intermediate compound is (10-20) mL:1 g; (e) Use a first deuterated reagent, the reaction temperature is the reflux temperature of the corresponding first deuterated reagent, and the reaction time is 1-5 days.

12. The light-emitting layer material according to claim 10, characterized in that, The second deuteration reaction satisfies at least one of the following conditions: a) The process is carried out in the presence of a second catalyst, wherein the second catalyst comprises at least one of a protic acid, a Lewis acid, and a polymerically bonded sulfonic acid; b) The process is carried out in the presence of a second catalyst, wherein the mass of the second catalyst is 3%-20% of the mass of the second intermediate compound; c) A second deuterated reagent is used, wherein the second deuterated reagent comprises deuterated benzene and / or deuterated water; d) A second deuterated reagent is used, and the volume ratio of the second deuterated reagent to the mass ratio of the second intermediate compound is (10-20) mL:1 g; e) Use a second deuterated reagent, and the reaction temperature is the reflux temperature of the corresponding second deuterated reagent, with a reaction time of 1-5 days.

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