Host compound, organic electroluminescent material containing double hosts and organic electroluminescent device

Abstract

The invention provides a main body compound, an organic electroluminescent material containing double main bodies and an organic electroluminescent device.The main body compound has a structure shown in the formula I. The double main body material comprises a first main body compound and a second main body compound, the first main body compound is the main body compound with the structure shown in the formula I, and the second main body compound is the main body compound with the structure shown in the formula II. And the second host compound has a structure as shown in a formula II. The dual-host material has the first host compound and the second host compound with specific structures, the first host compound has higher electron mobility, and the second host compound with the specific structure has higher hole mobility. The first host compound and the second host compound with specific structures are compounded, hole mobility and electron mobility can be balanced, so that the double-host material can increase the luminous efficiency and the service life of a device by adding excitons in the luminous layer, and the driving voltage can also be reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic optoelectronic materials, and particularly relates to a host compound, an organic electroluminescent material containing a double host, and an organic electroluminescent device. BACKGROUND

[0002] Since the discovery of organic electroluminescence (OLED) technology, it has developed rapidly in the past few decades due to its unique advantages in the fields of display and lighting, such as high contrast resulting from self-luminescence, wide viewing angle, and lightness, flexibility, and bending characteristics.

[0003] An organic electroluminescent device is usually composed of a multi-layer structure, which generally includes a substrate, an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. When a voltage is applied to the anode and the cathode, an electric field is generated between the two electrodes. Under the action of the electric field, electrons from the cathode move to the electroluminescent layer, and holes from the anode also move to the electroluminescent layer. Electrons and holes combine in the electroluminescent layer to form excitons. The excitons in the excited state release energy to the outside, and then the electroluminescent layer emits light. Among them, the host material in the emission layer has a great influence on the performance of the device. The traditional single host material needs to complete the functions of electron transport and hole transport at the same time. The single host material is difficult to meet the high performance requirements in terms of efficiency and service life, and the double host material is thus born.

[0004] However, the energy matching and charge transfer process between different hosts and guests of the double host luminescent material are not perfect. In some cases, there may be incomplete energy transfer or accumulation of charges in the host material, which prevents some excitons from being effectively converted into photons, reducing the overall luminescent efficiency and limiting the further improvement of the luminescent efficiency and service life of the double host material.

[0005] The organic electroluminescent double host material still faces many challenges in current research and application, and more double host materials are urgently needed to solve the problems existing in the prior art and promote the further development of OLED technology in the fields of display and lighting. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application aims to provide a host compound, an organic electroluminescent material containing double hosts and an organic electroluminescent device. In the present application, the double host material has a first host compound with a specific structure and a second host compound with a specific structure, the first host compound has a faster electron mobility, and the second host compound with the specific structure has a faster hole mobility. The first host compound and the second host compound with the specific structure are used in the present application to balance the hole and electron mobilities, so that the double host material can increase excitons in the light-emitting layer, thereby improving the luminous efficiency and service life of the device and reducing the driving voltage.

[0007] To achieve the object of the present application, the following technical solutions are used in the present application:

[0008] In one aspect, the present application provides a host compound, which has the structure shown in Formula I:

[0009] ;

[0010] Among them,

[0011] Y and Z are each independently selected from O or S;

[0012] R1 is selected from any one of substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C10-C30 fused ring group, and substituted or unsubstituted C3-C30 cycloalkyl;

[0013] Ra is selected from deuterium, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, and substituted or unsubstituted C10-C18 fused ring group;

[0014] m is selected from 0, 1, 2, 3 or 4;

[0015] L1 and L2 are each selected from any one of a bond, substituted or unsubstituted C6-C30 arylene, and substituted or unsubstituted C3-C30 heteroarylene;

[0016] In the above Formula I, hydrogen is substituted with deuterium or not substituted with deuterium.

[0017] Further, the host compound has the structures of Formula I-A-Formula I-D:

[0018] .

[0019] Further, L1 and L2 are each independently selected from any one of a bond, substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted thiophenylene, and substituted or unsubstituted furanylene.

[0020] Ra is selected from any one of deuterium, phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, deuterated biphenyl, furanyl, thienyl, cyclohexylphenyl, furanylbiphenyl, furanyldedeuterated phenyl, benzonaphthofuranyl, methylphenyl, tert-butylphenyl, tert-butylbiphenyl, fluorenyl, terphenyl, benzofluorene, phenanthryl, phenylnaphthalene, dibenzofuranyl, dibenzothienyl, dimethylfluorenyl, diphenylfluorenyl, deuterated dimethylfluorenyl;

[0021] R1is selected from any one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, deuterated biphenyl, furanyl, thienyl, cyclohexylphenyl, furanylbiphenyl, furanyldedeuterated phenyl, benzonaphthofuranyl, methylphenyl, tert-butylphenyl, tert-butylbiphenyl, fluorenyl, terphenyl, benzofluorene, phenanthryl, phenylnaphthalene, dibenzofuranyl, dibenzothienyl, dimethylfluorenyl, diphenylfluorenyl, deuterated dimethylfluorenyl, or the following group:

[0022] ;

[0023] wherein the wave line is a group connection site.

[0024] In the present application, the heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, and the heteroatom is O, S, N, P, Si, or B.

[0025] In the present application, the fused ring group includes a fused aromatic ring sharing at least two carbon atoms, and also includes two fused aromatic rings connected by a connecting bond.

[0026] In the present application, the "substitution" means that the hydrogen atom bonded to the carbon atom of the compound is changed to another substituent, and the position of substitution is not limited as long as it is the position of the hydrogen atom to be substituted, i.e., the position where the substituent can be substituted, and when two or more substituents are substituted, the two or more substituents can be the same as or different from each other.

[0027] The number of carbon atoms of the aryl group, heteroaryl group, fused ring group, arylene group, heteroarylene group, and cycloalkyl group in the terms "substituted or unsubstituted C6-C42 aryl group", "substituted or unsubstituted C6-C30 heteroaryl group", "substituted or unsubstituted C10-C30 fused ring group", "substituted or unsubstituted C3-C30 cycloalkyl group", "substituted or unsubstituted C6-C30 arylene group", and "substituted or unsubstituted C6-C30 heteroarylene group" indicates the total number of carbon atoms constituting the unsubstituted aryl group or unsubstituted alkyl group or the total number of heteroatoms and carbon atoms constituting the heteroaryl group, without considering the number of carbon atoms in the substituent.

[0028] The term "substituted" means substituted with one, two, or more substituents selected from cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthryl, triphenylenyl, furanyl, thienyl, pyrrolyl, pyridyl, benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, or a substituent in which two or more of the above substituents are connected.

[0029] In the present application, the host compound is any one of the following compounds H1-1 to H1-336, but is not limited thereto:

[0030] ;

[0031] wherein D represents deuterium.

[0032] In a second aspect, the present application also provides a dual-host material, which comprises a first host compound and a second host compound, the first host compound is the host compound as described in the first aspect above, and the second host compound has a structure shown in formula II:

[0033] ;

[0034] wherein L3, L4, L5 are each independently selected from any one of a bond, a substituted or unsubstituted C6-C42 arylene, a substituted or unsubstituted C3-C42 heteroarylene.

[0035] Ar1, Ar2, Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C42 aryl, a substituted or unsubstituted C3-C42 heteroaryl, a substituted or unsubstituted C10-C42 fused ring group.

[0036] The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, the heteroatom being O, S, N, P or B.

[0037] Further,

[0038] L3, L4, L5 are each independently selected from any one of a bond, a substituted or unsubstituted C6-C18 arylene group, a substituted or unsubstituted C3-C18 heteroarylene group;

[0039] Ar1, Ar2, Ar3 are each independently selected from any one of a substituted or unsubstituted C6-C18 aryl group, a substituted or unsubstituted C3-C18 heteroaryl group, a substituted or unsubstituted C10-C18 fused ring group.

[0040] The term "substituted" means substituted with one, two or more substituents selected from deuterium, cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthryl, triphenylenyl, furanyl, thienyl, pyrrolyl, pyridyl, benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl or dibenzothienyl or a substituent in which two or more of the substituents shown above are connected.

[0041] In the present application, the second host compound is any one of the following compounds H2-1 to H2-216, but is not limited thereto:

[0042]

[0043] ;

[0044] wherein D represents deuterium.

[0045] In one embodiment of the present application, the mass ratio of the first host compound to the second host compound is (10-90):(90-10), for example 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 60:40, 70:30, 80:20, or 90:10, preferably 60-40:40-60.

[0046] In a third aspect, the present application also provides a preparation method of the host compound having the structure shown in Formula I.

[0047] Synthesis of the compound of Formula I:

[0048] Synthesis of the compound of Formula I:

[0049]

[0050] Synthesis of the compound of Formula I:

[0051] Under a nitrogen protection system, the raw material 1 (1 eq), the raw material 2 (1.5-1.8 eq), and potassium acetate (2.5-3.0 eq) are weighed and put into a reaction system, 1,4-dioxane and a catalyst tris(dibenzylideneacetone)dipalladium (0.02-0.04 eq) and x-phos (0.16-0.32 eq) are added, and the reaction system is refluxed at 100-110°C for 20-24h under nitrogen protection. After the reaction is completed, the reaction system is cooled to 25°C, pure water is added, and after stirring, the reaction system is allowed to stand and separate into two layers. After the liquid separation treatment, the intermediate compound I-1 is obtained by column chromatography purification.

[0052] Under a nitrogen protection system, the raw material 3 (1 eq) and the raw material 4 (1-1.1 eq) are weighed and put into a reaction system, potassium carbonate (2.5-3.0 eq) is added, toluene, ethanol, water, and a catalyst tetrakis(triphenylphosphine)palladium (0.02-0.05 eq) are added, and the reaction system is refluxed at 90-100°C for 20-24h under nitrogen protection. After the reaction is completed, the reaction system is cooled to 25°C, pure water is added, and after stirring, the reaction system is allowed to stand and separate into two layers. After the liquid separation treatment, the intermediate compound I-2 is obtained by column chromatography purification.

[0053] Under a nitrogen protection system, the intermediate compound I-2 (1 eq) and the intermediate compound I-1 (1.0-1.1 eq) are weighed and put into a reaction system, potassium carbonate (2.5-3.0 eq) is added, toluene, ethanol, water, and a catalyst tetrakis(triphenylphosphine)palladium (0.02-0.05 eq) are added, and the reaction system is refluxed at 90-100°C for 20-24h under nitrogen protection. After the reaction is completed, the reaction system is cooled to 25°C, pure water is added, and after stirring, the reaction system is allowed to stand and separate into two layers. After the liquid separation treatment, the intermediate compound I-3 is obtained by column chromatography purification.

[0054] Under nitrogen protection, raw material 5 (1 eq), raw material 6 (1.0-1.1 eq), and potassium carbonate (2.5-3.0 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.02-0.05 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-4 shown.

[0055] Under nitrogen protection, intermediate compound I-4 (1 eq), raw material 2 (1.5-1.8 eq), and potassium acetate (2.5-3.0 eq) were weighed and added to the reaction system. 1,4-Dioxane and catalysts tris(dibenzylacetone)dipalladium (0.02-0.04 eq) and x-phos (2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.16-0.32 eq) were added. The mixture was refluxed at 100-110℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound I-5 as shown.

[0056] Under nitrogen protection, intermediate compound I-5 (1 eq), intermediate compound I-3 (1.0-1.1 eq), and potassium carbonate (2.5-3.0 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.02-0.05 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain compound I as shown.

[0057] Wherein, L1, L2, R1, Ra, m, Z, and Y are each independently selected from the same range as Formula I; X is selected from halogens; the halogens include fluorine, chlorine, bromine, or iodine, preferably chlorine or bromine, and most preferably chlorine.

[0058] Fourthly, the present invention also provides a method for preparing a host compound having the structure shown in Formula II.

[0059] In one embodiment of the present invention, the reaction route of the second host compound having the structure shown in Formula II is as follows:

[0060] .

[0061] Specific preparation methods include:

[0062] (1) Weigh raw material A (1 eq), raw material B (1 eq), and sodium tert-butoxide (2 eq) and add them to the reaction vessel in sequence. Then add toluene as the reaction solvent. Under nitrogen protection, add catalysts Pd2(dba)3 (tris(dibenzylideneacetone)dipalladium, 0.01 eq) and P(t-Bu)3 (tritert-tert-butylphosphine, 0.02 eq). Reflux at 120°C for 24 hours under nitrogen protection. Then cool to 25°C, add pure water, stir for 30 minutes, let stand for layering, separate the liquid and liquid, and perform column chromatography to obtain intermediate formula II-1.

[0063] (2) Weigh intermediate II-1 (1 eq), raw material C (1 eq), and sodium tert-butoxide (2 eq) and add them sequentially to the reaction vessel. Then add toluene as the reaction solvent. Under nitrogen protection, add catalysts Pd2(dba)3 (0.01 eq) and P(t-Bu)3 (0.02 eq). Reflux at 120°C for 24 hours under nitrogen protection. Then cool to 25°C, add pure water, stir for 30 minutes, let stand for layering, separate the liquid and liquid, and perform column chromatography to obtain the second main compound with the structure shown in formula II.

[0064] Wherein, L3, L4, L5, Ar1, Ar2, and Ar3 are each independently selected from the same range as Formula I; X is selected from halogens; the halogens include fluorine, chlorine, bromine, or iodine, preferably chlorine or bromine, and most preferably chlorine.

[0065] Fifthly, the present invention also provides an organic electroluminescent material, wherein the organic electroluminescent material comprises the dual host material.

[0066] Preferably, the organic electroluminescent material further includes a dopant material.

[0067] Preferably, the mass ratio of the dual host material to the doped material in the organic electroluminescent material is (5~199):1, for example, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, 120:1, 130:1, 140:1, 150:1, 160:1, 170:1, 180:1, 190:1 or 199:1, etc., further preferably (5~100):1, more preferably (5~15):1.

[0068] In a sixth aspect, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising the dual host material or the organic electroluminescent material.

[0069] In this invention, the organic electroluminescent device includes a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode arranged sequentially; the material of the light-emitting layer includes the dual-host material or the organic electroluminescent material.

[0070] In this invention, the method for preparing the light-emitting layer includes, but is not limited to, forming the light-emitting layer from the organic electroluminescent material by solution coating and vacuum deposition; the solution coating method refers to spin coating, dip coating, inkjet printing, screen printing, spraying, etc., but is not limited to these.

[0071] In this invention, the first electrode is the anode.

[0072] In this invention, the anode material is preferably a material with a high work function in order to enable holes to be smoothly injected into the organic layer.

[0073] In this invention, the anode material includes: metals, such as vanadium, chromium, copper, zinc, or their alloys; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO), or indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO / Al or SnO2 / Sb; conductive polymers, such as poly(3-methylthiophene), polypyrrole, or polyaniline; but is not limited thereto.

[0074] In this invention, the anode is an ITO anode.

[0075] In this invention, the material of the hole injection layer is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection layer material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0076] In this invention, the hole injection material includes metalloporphyrin, oligothiophene, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, and conductive polymers based on polyaniline or polythiophene.

[0077] In this invention, the hole transport layer material is a material that can receive holes from the anode or hole injection layer and transport the holes to the light-emitting layer, and has a high hole mobility.

[0078] In this invention, the hole transport layer material includes, but is not limited to, arylamine-based organic materials, conductive polymers, block copolymers having both conjugated and non-conjugated portions.

[0079] In this invention, the electron transport layer plays a role in promoting electron transport. The electron transport layer material is a material with high electron mobility used to receive electrons from the cathode and transport them to the light-emitting layer.

[0080] In this invention, the material of the electron transport layer includes an Al complex of 8-hydroxyquinoline and an organic free radical compound.

[0081] In this invention, the thickness of the electron transport layer is set to 1 nm to 50 nm, for example, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm.

[0082] The electron transport layer can prevent the electron transport characteristics from degrading and prevent the driving voltage from increasing due to the electron transport layer being too thick.

[0083] In this invention, the electron injection layer can promote electron injection, and the electron injection material preferably has the ability to transport electrons, has the electron injection effect from the cathode, has an excellent electron injection effect on the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and has excellent thin film forming ability.

[0084] In this invention, the material of the electron injection layer includes one or more of fluorenone, anthraquinone dimethane, biphenylquinone, thiamethane dioxide, imidazole, perylenetetracarboxylic acid, fluorenemethane, anthrone, and their derivatives, metal complexes, and nitrogen-containing five-membered ring derivatives.

[0085] In this invention, the second electrode is a cathode.

[0086] As a cathode material, a material with a low work function is generally preferred in order to facilitate the injection of electrons into the organic layer.

[0087] In one embodiment of the present invention, the cathode material includes: a metal, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or alloys thereof; a multilayer structure material, such as LiF / Al or LiO2 / Al; but is not limited thereto. In some embodiments of the present invention, the cathode material is Al.

[0088] In this invention, the organic electroluminescent device can be a top-emitting type, a bottom-emitting type, or a dual-sided emitting type.

[0089] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0090] Compared with the prior art, the present invention has the following beneficial effects:

[0091] The dual-host material provided by this invention comprises a first host compound and a second host compound with specific structures. The first host compound exhibits a faster hole mobility, while the second host compound exhibits a faster electron mobility. This dual-host material combines two host compounds with different properties. By compounding the first and second host compounds with specific structures, it serves as the emitting layer material for organic electroluminescent devices. This balances hole and electron mobility, allowing the dual-host material to increase excitons in the emitting layer, thereby improving not only the luminous efficiency and lifespan of the device but also reducing the driving voltage. Attached Figure Description

[0092] Figure 1 The 1H NMR spectrum of the first host compound H1-100 prepared in Preparation 1. Detailed Implementation

[0093] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0094] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0095] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible. However, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0096] Unless otherwise stated, the raw materials and reagents used in the following examples are all commercially available products.

[0097] The following are common knowledge references:

[0098] Organometallic Chemistry (6th Edition), Robert H. Crabtree, published by East China University of Science and Technology Press, Shanghai, September 00, 2017, ISBN: 978-7-5628-5111-0, page 388.

[0099] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0100] This invention specifically discloses an organic electroluminescent material, its preparation method, and its application.

[0101] The features and performance of the present invention will be further described in detail below with reference to specific preparation examples.

[0102] Preparation Example 1

[0103] Preparation of the first host compound H1-100

[0104] Under nitrogen protection, raw materials H1-100-1 (1 eq), H1-100-2 (1 eq), potassium acetate (2.5 eq), tris(dibenzylacetone)dipalladium (0.01 eq), X-phos (0.08 eq), and 1,4-dioxane were added to a three-necked flask. The mixture was heated to 100°C and refluxed for 20 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound H1-100-1.

[0105] Under nitrogen protection, raw material H1-100-3 (1 eq), intermediate compound H1-100-1 (1 eq), potassium carbonate (2 eq), tetrakis(triphenylphosphine)palladium (0.02 eq), toluene, ethanol, and water were added to a three-necked flask. The mixture was heated to 90°C and refluxed for 20 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound H1-100-2.

[0106] Under nitrogen protection, the following compounds were added to a three-necked flask: starting material H1-100-4 (1 eq), intermediate compound H1-100-2 (1 eq), potassium carbonate (2 eq), tetrakis(triphenylphosphine)palladium (0.02 eq), toluene, ethanol, and water. The mixture was heated to 90°C and refluxed for 20 hours. After the reaction was complete, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the first main compound H1-100 (15.60 g, yield 63.50%, HPLC > 99%, mass spectrometry value 646.23). The reaction route is shown below.

[0107] The 1H NMR spectrum of H1-100 is shown below. Figure 1 .

[0108] ;

[0109] .

[0110] Preparation Example 2

[0111] Preparation of the second host compound H2-47

[0112] Under nitrogen protection, raw materials H2-47-1 (1 eq), H2-47-2 (1 eq), and sodium tert-butoxide (1.5 eq) were weighed and added to a reaction flask. Toluene was added, and catalysts Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.04 eq) were added under nitrogen protection. The mixture was refluxed at 120 °C for 24 hours under nitrogen protection, then cooled to 25 °C, purified water was added, and the mixture was stirred for 30 minutes. After standing and separating the layers, the mixture was separated and subjected to column chromatography to obtain product H2-47 (13.41 g, yield 68%, HPLC > 99%, mass spectrometry value 578.25). The reaction route is shown below.

[0113] .

[0114] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the preparation examples listed above, so they will not be listed one by one here.

[0115] Examples 1-40, Comparative Examples 1-43

[0116] Examples 1-40 and Comparative Examples 1-43 each provide a host material, the formulation of which is shown in Table 1. For the dual host material scheme, which includes a first host compound and a second host compound, the mass ratio of the first host compound and the second host compound is 60:40.

[0117] The structures of D-1 to D-6 are shown below.

[0118] .

[0119] The fabrication method of organic electroluminescent devices includes the following steps:

[0120] (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was washed twice with distilled water and ultrasonically washed for 30 min. Then it was washed twice with distilled water and ultrasonically washed for 10 min. After washing, it was ultrasonically washed sequentially with methanol, acetone and isopropanol (5 min each time), dried, and then transferred to a plasma cleaner for 5 min to obtain the ITO anode.

[0121] (2) In the vapor deposition machine, HIL is vacuum vapor deposited on the ITO anode surface obtained in step (1) with a thickness of 200 Å to obtain a hole injection layer.

[0122] (3) A hole transport layer is obtained by vacuum evaporation of HTL on the surface of the hole injection layer obtained in step (2) with a thickness of 400 Å.

[0123] (4) Evaporate the light-emitting layer material on the surface of the hole transport layer and perform linear gradient co-evaporation using a multi-source co-evaporation method to obtain a light-emitting layer with a thickness of 300 Å. The material of the light-emitting layer includes a dual host material and a dopant material. The mass ratio of the first host compound and the second host compound is 60:40, and the mass ratio of the dual host material and the dopant material is 10:1. The dual host materials are the host materials provided in Examples 1-30 and Comparative Examples 1-41, respectively.

[0124] (5) A hole blocking layer is formed by vapor deposition of BAlq on the surface of the light-emitting layer obtained in step (4) with a thickness of 100 Å.

[0125] (6) Vacuum vapor deposition of ETL on the surface of the hole blocking layer obtained in step (5) with a thickness of 400 Å is obtained to obtain the electron transport layer.

[0126] (7) A Liq layer with a thickness of 15 Å is vacuum-deposited on the surface of the electron transport layer obtained in step (6); an electron injection layer is obtained.

[0127] (8) A 1500 angstrom layer of Al is deposited on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0128] The structure of the materials used is as follows:

[0129] .

[0130] The driving voltage, luminous efficiency, and time (lifetime; T95) of the organic electroluminescent device at a brightness of 5000 nits were tested. The test results are shown in Table 1. In Table 1, "-" indicates that the compound is not present in the host material.

[0131] Table 1

[0132]

[0133] As shown in Table 1, the dual-host material provided by the present invention, which employs a first host compound and a second host compound with specific structures, can reduce the driving voltage of the device, improve the luminous efficiency of the device, and extend the service life of the device.

[0134] As can be seen from the comparison between Examples 1-30 and Comparative Examples 1-41, the main material of the light-emitting layer is a combination of the first main compound and the second main compound, which can greatly improve the luminous efficiency and lifespan. If only one of them is selected, the luminous efficiency of the device will be greatly reduced, the lifespan will be significantly shortened, and the voltage will increase.

[0135] As can be seen from Examples 1-40 and Comparative Examples 7-18, the luminous efficiency of Comparative Examples 7-18 is 29.5-30.7 cd / A, the driving voltage is 3.52-3.64 V, and the lifetime is 327-344 h. In contrast, the luminous efficiency of Examples 1-40 of the present invention is 38.7-43.4 cd / A, which is significantly higher than that of Comparative Examples 7-18. The driving voltage of Examples 1-40 of the present invention is 3.22-3.39 V, which is significantly lower than that of Comparative Examples 7-18. The lifetime of Examples 1-40 of the present invention is 460-491 h, which is much higher than that of Comparative Examples 7-18.

[0136] On the one hand, the nitrogen-containing heterocyclic compounds provided by this invention have high electron mobility and high triplet energy levels, which can effectively improve the binding efficiency of holes and electrons, thereby improving the luminous efficiency of organic electroluminescent devices. Furthermore, they can effectively block the migration of holes to the electron transport layer, reducing the electron injection transport barrier, lowering the driving voltage, avoiding excessively high local voltage, and extending the device's lifespan. On the other hand, the constituent groups in the compounds of this invention are highly rigid, exhibiting characteristics such as poor intermolecular crystallization, poor aggregation, good film-forming properties, high glass transition temperature, and thermal stability. Therefore, when the compounds of this invention are applied to OLED devices, they can maintain the stability of the film layer after material formation, extending the device's lifespan. Thus, it can be seen that when the main material of the light-emitting layer is a combination of the first main compound with a specific structure and the second main compound with a specific structure of this invention, the driving voltage can be significantly reduced, and the luminous efficiency and lifespan can be improved.

[0137] As can be seen from the test results of Comparative Examples 1-6 and Comparative Examples 19-43, which are devices with only a single host material, the performance of devices including the first host compound with a specific structure provided by the present invention is slightly higher than that of single host compounds in the prior art. The host material provided by the present invention has better performance.

[0138] The applicant declares that the present invention is illustrated through the above embodiments to demonstrate the main compound, the dual-host organic electroluminescent material, and the light-emitting device of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A host compound, characterized in that, The host compound has the structure shown in Formula I: ； in, Y and Z are each independently selected from O or S; R1 is selected from any one of substituted or unsubstituted C6~C42 aryl, substituted or unsubstituted C3~C30 heteroaryl, substituted or unsubstituted C10~C30 fused cyclic group, and substituted or unsubstituted C3~C30 cycloalkyl. Ra is selected from deuterium, substituted or unsubstituted C6~C18 aryl, substituted or unsubstituted C6~C18 heteroaryl, and substituted or unsubstituted C10~C18 fused ring group; m is selected from 0, 1, 2, 3 or 4; L1 and L2 are each selected from any one of the following: the linking bond, substituted or unsubstituted C6~C30 arylene, and substituted or unsubstituted C3~C30 heteroarylene; In Formula I above, hydrogen may be either substituted with deuterium or not substituted with deuterium; "Substitution" means substitution by one, two or more substituents selected from the following: cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthrene, triphenylene, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl, dibenzothiophene, or a substituent connected to two or more of the substituents shown above.

2. The main compound according to claim 1, characterized in that, The host compound has the following structure: Formula IA-Formula ID: 。 3. The main compound according to claim 1 or 2, characterized in that, L1 and L2 are each independently selected from any one of the following: linking bond, substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted thiopheneylene, and substituted or unsubstituted furanylene; Ra is selected from any one of deuterium, phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, deuterated biphenyl, furanyl, thiophene, cyclohexylphenyl, furanyl-2-phenyl, furanyl-2-deuterated phenyl, benzonaphthyl-2-furanyl, methylphenyl, tert-butylphenyl, tert-butylbiphenyl, fluorenyl, terphenyl, benzo[a]fluorene, phenanthrene, phenylnaphthalene, dibenzofuranyl, dibenzo[a]thiophene, dimethylfluorenyl, diphenylfluorenyl, and deuterated dimethylfluorenyl. R1 is selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, deuterated biphenyl, furanyl, thiophene, cyclohexylphenyl, furanyl-2-phenyl, furanyl-2-deuterated phenyl, benzonaphthofuranyl, methylphenyl, tert-butylphenyl, tert-butylbiphenyl, fluorenyl, tert-phenyl, benzo[a]fluorene, phenanthrene, phenylnaphthalene, dibenzofuranyl, dibenzo[a]thiophene, dimethylfluorenyl, diphenylfluorenyl, deuterated dimethylfluorenyl, or any one of the following groups: ； The wavy lines indicate group connection sites.

4. The host compound according to claim 1, characterized in that, The host compound is any one of the following compounds H1-1 to H1-336: 。 5. A dual-body material, characterized in that, The dual-host material comprises a first host compound and a second host compound, wherein the first host compound is the host compound according to any one of claims 1-4, and the second host compound has the structure shown in Formula II: ； L3, L4, and L5 are each independently selected from any one of the following: the linking bond, substituted or unsubstituted C6-C42 arylene, and substituted or unsubstituted C3-C42 heteroarylene; Ar1, Ar2, and Ar3 are each independently selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C3-C42 heteroaryl, or substituted or unsubstituted C10-C42 fused cyclic group; The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, wherein the heteroatom is O, S, N, P or B.

6. The dual-body material according to claim 5, characterized in that, L3, L4, and L5 are each independently selected from any one of the following: the linking bond, substituted or unsubstituted C6-C18 arylene, and substituted or unsubstituted C3-C18 heteroarylene; Ar1, Ar2, and Ar3 are each independently selected from any one of the following: substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C3-C18 heteroaryl, or substituted or unsubstituted C10-C18 fused ring group; The term "substitution" means substitution by one, two or more substituents selected from the following: deuterium, cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthrene, triphenylene, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl or dibenzothiophene, or a substituent connected to two or more of the substituents shown above.

7. The dual-body material according to claim 5, characterized in that, The second host compound is any one of the following compounds H2-1 to H2-216: 。 8. The dual-body material according to claim 5, characterized in that, The mass ratio of the first main compound to the second main compound is (10~90):(90~10).

9. An organic electroluminescent material, characterized in that, The organic electroluminescent material comprises the dual host material and the doped material as described in any one of claims 5-8, wherein the mass ratio of the dual host material to the doped material in the organic electroluminescent material is (5~199):

1.

10. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode arranged sequentially; the material of the light-emitting layer comprises the dual-host material of any one of claims 5-8 or the organic electroluminescent material of claim 9.

Images