Organic material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of organic materials, in particular to an organic material and a preparation method and application thereof. The organic material comprises a boron-nitrogen-like skeleton unit formula (I) and a substituted structural unit formula (II-1) and / or a substituted structural unit formula (II-2), wherein at least one substituted structural unit and at least one ring structure in the boron-nitrogen-like skeleton unit form a substituted bond; according to the organic material disclosed by the invention, through the flexible modification effect of high-rigidity polycyclic aromatic amine of a substituted structural unit on a boron-nitrogen-like skeleton, the constructed organic material is capable of narrowing the light-emitting FWHM, realizing flexible adjustment of light color and improving the photoluminescence quantum yield, and the application requirements of photoelectric devices on the light-emitting organic material with high color rendering index and high reduction degree are better met.

Description

Technical Field

[0001] This application belongs to the technical field of organic materials, and particularly relates to an organic material, a preparation method thereof, and an application thereof. Background Art

[0002] Organic semiconductor materials have diversity in chemical synthesis, relatively low manufacturing costs during large-scale production, and excellent optical and electrical properties. Therefore, organic light-emitting diodes (OLEDs) based on organic semiconductor materials have great potential in various display intelligent terminal applications. Usually, an OLED device has a multi-layer structure, and each layer contains different organic substances. Specifically, an organic electroluminescent device may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. In such an organic electroluminescent device, when a voltage is applied between two electrodes, holes are injected into the device from the anode, and electrons are injected into the device from the cathode. Under the action of an electric field, the holes generated by the anode and the electrons generated by the cathode will move, and are respectively injected into the hole transport layer and the electron transport layer, and migrate to the light-emitting layer. When the injected holes and electrons meet in the light-emitting layer, energy excitons are generated. When the excitons transition back to the ground state, photons with the same energy as the energy gap are emitted, thereby exciting the light-emitting molecules to finally generate visible light.

[0003] Existing luminescent materials for blue OLED devices are mostly traditional fluorescent molecules such as pyrene, anthracene, perylene, etc. The full width at half maximum (FWHM) of the luminescence spectrum of such molecules is relatively wide, and it is difficult to achieve deep blue light in the display effect, which does not meet the requirements of high color rendering index display technology. Moreover, the efficiency of devices using such materials is relatively low, which is not conducive to realizing low-power consumption and long-service-life display devices.

[0004] Therefore, it is particularly important to develop a blue organic material with a narrow full width at half maximum of the luminescence spectrum, high light color regulation, and high luminescence quantum yield for blue OLED devices. Summary of the Invention

[0005] The purpose of this application is to provide an organic material, a preparation method thereof, and an application thereof, aiming to solve the problems of the relatively wide full width at half maximum of the luminescence spectrum, poor light color regulation performance, and low luminescence efficiency of existing blue organic materials.

[0006] To achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In the first aspect of this application, an organic material is provided, which includes the following boron-nitrogen-like framework unit formula (I) and substituted structural unit formula (II-1) and / or formula (II-2), and at least one of the substituted structural units forms a substitution bond with at least one ring structure in the boron-nitrogen-like framework unit;

[0008] Among them, ring A, ring B, and ring C are each independently selected from one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; X is selected from B, N, P, P═O, or Al; Y and Z are each independently selected from C═O, N-R3, O, S, Se, P, P═O, or P═S; R1, R2, and R3 are each independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al.

[0009] The organic material provided by this application adopts a boron-nitrogen-like structure as the backbone structure, and a polycyclic aromatic amine unit with a fused ring structure is introduced as a substituted structural unit on at least one ring structure in the boron-nitrogen-like backbone unit. This substituted structural unit has high rigidity. After introducing the high-rigidity polycyclic aromatic amine unit into the boron-nitrogen-like backbone unit, it can effectively reduce the number of phenyl groups that freely rotate within the molecule, inhibit the vibration and rotational degrees of freedom of the internal groups of the molecule, thereby effectively narrowing the full width at half maximum (FHWM) of the luminescence of the organic material and improving the luminescence efficiency and color purity of the material. Through the flexible modification of the boron-nitrogen-like backbone by the high-rigidity polycyclic aromatic amine of the substituted structural unit, the constructed organic material narrows the luminescence FWHM, enables flexible adjustment of the light color, improves the photoluminescence quantum yield, and better meets the application requirements of optoelectronic devices for organic materials with high color rendering index and high reduction degree of luminescence.

[0010] As some possible implementation manners of the organic material of this application, the organic material includes at least one of the following formulas (III), (IV), (V), and (VI);

[0011] In this case, for the organic materials with configurations such as formula (III), formula (IV), formula (V), and formula (VI), through the modification of the boron-nitrogen-like backbone by the high-rigidity polycyclic aromatic amine of the substituted structural unit, the organic material has a narrow FHWM and improves the performance such as luminescence efficiency and color purity of the organic material.

[0012] As some possible implementation manners of the organic material of this application, X is selected from B. In this case, the boron-nitrogen-like backbone unit in the organic material contains boron element.

[0013] As some possible implementation manners of the organic material of this application, at least one of Y and Z is selected from N. In this case, the boron-nitrogen-like backbone unit in the organic material contains nitrogen element.

[0014] As some possible implementation manners of the organic material of the present application, Y and Z are selected from the same element. Exemplarily, both Y and Z are N. In this case, the boron-nitrogen cyclized structure in the skeleton structure is more conducive to improving the optoelectronic performance of the organic material.

[0015] As some possible implementation manners of the organic material of the present application, the A ring and the B ring are each independently selected from one of a substituted aryl group, a substituted heteroaryl group, and a substituted condensed ring group. In this case, the selection of the A ring, the B ring, and the C ring in the boron-nitrogen-like skeleton unit will to some extent affect the optical performance of the constructed organic material. When the A ring and the B ring are each independently selected from one of a substituted aryl group, a substituted heteroaryl group, and a substituted condensed ring group, the formed boron-nitrogen-like skeleton unit and the polycyclic aromatic amine substitution unit with a fused ring structure construct an organic material, which is beneficial to reducing the width of the full width at half maximum (FWHM) of the emission spectrum of the organic material and improving the emission efficiency and color purity of the organic material.

[0016] As some possible implementation manners of the organic material of the present application, the C ring is selected from an aryl group. In this case, when the C ring is selected from an aryl group, the polycyclic aromatic amine unit with a fused ring structure can easily be bonded to the C ring through substitution, increasing the rigidity within the organic material molecule, reducing the width of the FWHM of the emission spectrum of the organic material, and improving the emission efficiency and color purity of the organic material.

[0017] As some possible implementation manners of the organic material of the present application, at least one of W1 or V1 is selected from N, or at least one of W2 or V2 is selected from N. In this case, the nitrogen atom can form a covalent bond with other atoms, enabling the compound to form a dense aromatic ring structure. Moreover, the nitrogen atom is more electronegative than the boron atom. Therefore, the nitrogen atom in the boron-nitrogen heteroaromatic condensed ring compound can increase the chargeability and polarity of the entire molecule through conjugation.

[0018] As some possible implementation manners of the organic material of the present application, W1 and V1 are selected from the same element, or W2 and V2 are selected from the same element. In this case, it is more conducive to increasing the overall chargeability of the organic material molecule and regulating the molecular properties.

[0019] As some possible implementation manners of the organic material of the present application, the organic material includes Compound 1 Compound 2 Compound 3 Compound 4 At least one of them. In this case, the organic materials of Compound 1 to Compound 4 are blue-light materials with high molecular rigidity. Through the flexible modification of the boron-nitrogen-like framework by the highly rigid polycyclic aromatic amine with a substituted structural unit, the emission FWHM is narrowed, enabling flexible adjustment of the light color, improving the color rendering index, luminous efficiency, and color purity of the blue-light organic materials, and better meeting the application requirements of optoelectronic devices such as blue-light OLEDs.

[0020] In a second aspect, the present application provides a method for preparing an organic material, comprising the following steps:

[0021] Connect at least one of the following substituted structural units of formula (II-1) and / or formula (II-2) to at least one ring structure of the boron-nitrogen-like framework unit of formula (I) through a substitution reaction to obtain the organic material;

[0022] Wherein, ring A, ring B, and ring C are each independently selected from one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted fused ring group; X is selected from B, N, P, P=O, or Al; Y and Z are each independently selected from C=O, N-R3, O, S, Se, P, P=O, or P=S; R1, R2, and R3 are selected from one of a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted fused ring group; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al.

[0023] In this way, in the method for preparing the organic material of the present application, at least one polycyclic aromatic amine substituted structural unit with a fused ring structure is connected to at least one ring structure of the boron-nitrogen-like framework unit through a substitution reaction to construct a new organic material. Among them, the substituted structural unit has high rigidity. After the highly rigid polycyclic aromatic amine unit is bonded to the boron-nitrogen-like framework unit through a substitution reaction, the number of phenyl groups that can freely rotate within the molecule can be effectively reduced, thereby effectively inhibiting the vibration and rotational degrees of freedom of the groups inside the newly constructed organic material molecule, narrowing the emission FHWM of the organic material, and improving the luminous efficiency and color purity of the material.

[0024] As some possible implementation manners of the method for preparing the organic material of the present application, the organic material includes Compound 1 Compound 2 Compound 3 Compound 4 At least one of them. In this case, the organic materials of Compound 1 to Compound 4 are blue light materials with high molecular rigidity. Through the flexible modification of the boron-nitrogen-like skeleton by the highly rigid polycyclic aromatic amine of the substituted structural unit, the emission FWHM is narrowed, the light color can be flexibly adjusted, the color rendering index, luminous efficiency and color purity of the blue light organic materials are improved, and the application requirements of optoelectronic devices such as blue light OLED can be better met.

[0025] As some possible implementation manners of the preparation method of the organic material of the present application, the following steps are included:

[0026] Using 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole through the first substitution reaction to obtain Intermediate 1;

[0027] Subjecting the Intermediate 1 to a second substitution reaction with 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine to obtain Intermediate 2;

[0028] Subjecting the Intermediate 2 to a third substitution reaction with 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine to obtain Intermediate 3 respectively, and the Intermediate 3 includes Intermediate 3-1, Intermediate 3-2, Intermediate 3-3 or Intermediate 3-4;

[0029] Subjecting the Intermediate 3 to a substitution cyclization reaction respectively to obtain the Compound 1, the Compound 2, the Compound 3 or the Compound 4.

[0030] As some possible implementation manners of the preparation method of the organic material of the present application, the temperature condition of the first substitution reaction is 80°C to 120°C, and the reaction duration is 6h to 10h. Under this reaction condition, it is beneficial to the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole to generate Intermediate 1.

[0031] As some possible implementation manners of the preparation method of the organic material of the present application, the catalyst for the first substitution reaction includes at least one of cesium carbonate anhydrous, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide. Under the conditions of these catalysts, it is beneficial to catalyze the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole to generate Intermediate 1, improve the product purity, and improve the yield.

[0032] As some possible implementation manners of the preparation method of the organic material of the present application, the solvent for the first substitution reaction includes at least one of N,N-dimethylformamide, tetrahydrofuran, 2-methyltetrahydrofuran, acetone, 1,4-dioxane, acetonitrile, diethylene glycol dimethyl ether, toluene, and dichloromethane. In this case, these solvents have good solubility for both 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole, providing a solution environment for the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole, facilitating the substitution reaction to proceed and generating intermediate 1.

[0033] As some possible implementation manners of the preparation method of the organic material of the present application, the second substitution reaction is carried out under stirring conditions with heating to reflux for 12 h to 24 h. Under this condition, intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine undergo a second substitution reaction to generate intermediate 2.

[0034] As some possible implementation manners of the preparation method of the organic material of the present application, the catalyst for the second substitution reaction includes at least one of cesium carbonate anhydrous, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide. Under the conditions of these catalysts, it is beneficial to catalyze the substitution reaction between intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine to generate intermediate 2, improving the product purity and the yield.

[0035] As some possible implementation manners of the preparation method of the organic material of the present application, the solvent for the second substitution reaction includes at least one of diphenyl ether and dibenzyl ether. In this case, these solvents have good solubility for both intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine, providing a solution environment for the substitution reaction between intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine, facilitating the substitution reaction to proceed and generating intermediate 2.

[0036] As some possible implementation manners of the preparation method of the organic material of the present application, the third substitution reaction is carried out under stirring conditions with heating to reflux for 12 h to 24 h. Under this condition, it fully ensures the progress of the third substitution reaction, respectively generating intermediates 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3, or intermediate 3-4.

[0037] As some possible implementations of the method for preparing the organic material of the present application, the catalyst of the third substitution reaction includes tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and anhydrous sodium tert-butoxide. Under the conditions of these catalysts, it is conducive to catalyzing the substitution reaction between intermediate 2 and 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine, respectively generating intermediate 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4.

[0038] As some possible implementations of the method for preparing the organic material of the present application, the solvent of the third substitution reaction includes at least one of toluene, benzene, chlorobenzene, tetrahydrofuran, diethylene glycol dimethyl ether, and dichloromethane. Under these solvent conditions, these solvents have good solubility for each component, provide a solution environment for the substitution reaction, and are conducive to the generation of intermediate 3.

[0039] As some possible implementations of the method for preparing the organic material of the present application, the step of the substitution cyclization reaction includes: after dissolving the intermediate 3 in an organic solvent, adding a lithium reagent dropwise at a temperature not higher than 10°C, heating to 80°C to 120°C for reaction for 1h to 3h; dropping a boron source dropwise at a temperature not higher than 10°C, heating to 160°C to 200°C for reaction for 6h to 10h; dropping N,N-diisopropylethylamine dropwise at a temperature not higher than 10°C, heating to 160°C to 200°C for reaction for 12h to 24h; separating to obtain the organic material. Under this reaction condition, it is conducive to the intermediate 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 to undergo substitution cyclization reaction respectively to form a boron nitrogen heteroaromatic condensed ring compound, and obtain the compound 1, the compound 2, the compound 3 or the compound 4 respectively.

[0040] As some possible implementations of the method for preparing the organic material of the present application, the organic solvent includes at least one of tert-butylbenzene. In this case, these organic solvents have good solubility for components such as intermediate 3, lithium reagent, and boron source, providing a solution environment for the reaction between the components, which is conducive to the preparation of compounds 1 to 4.

[0041] As some possible implementation manners of the preparation method of the organic material of the present application, the lithium reagent includes at least one of n-butyllithium, tert-butyllithium, and lithium diisopropylamide. In this case, these lithium reagents are all beneficial to the substitution cyclization reactions of intermediate 3-1, intermediate 3-2, intermediate 3-3, or intermediate 3-4 respectively to form a boron-nitrogen heteroaromatic fused ring compound, and the compound 1, the compound 2, the compound 3, or the compound 4 is obtained respectively.

[0042] As some possible implementation manners of the preparation method of the organic material of the present application, the boron source includes at least one of boron tribromide. In this case, these boron sources are all beneficial to the substitution cyclization reactions of intermediate 3-1, intermediate 3-2, intermediate 3-3, or intermediate 3-4 respectively to form a boron-nitrogen heteroaromatic fused ring compound, and the compound 1, the compound 2, the compound 3, or the compound 4 is obtained respectively.

[0043] In a third aspect, the present application provides an organic electroluminescent device, including an anode, a cathode, and a light-emitting layer stacked between the anode and the cathode, wherein the light-emitting layer contains the above-mentioned organic material or the organic material prepared by the above method.

[0044] The organic electroluminescence provided by the present application contains the above-mentioned organic material in the light-emitting layer between the anode and the cathode. The skeleton structure adopted by the organic material is a boron-nitrogen-like structure. The substitution structural unit introduced on at least one ring structure in the boron-nitrogen-like skeleton unit is a polycyclic aromatic amine unit with a fused ring structure. This substitution structural unit has high rigidity, can effectively reduce the number of phenyl groups rotating freely in the molecule, inhibit the vibration and rotational freedom of the internal groups of the molecule, effectively narrow the full width at half maximum (FHWM) of the luminescence of the organic material, and improve the luminescence efficiency and color purity of the organic material. Therefore, the current efficiency, external quantum efficiency, photoelectric conversion efficiency, service life, and other optoelectronic properties of the organic electroluminescent device are improved, making the organic electroluminescent device have characteristics such as self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high responsiveness.

[0045] As some possible implementation manners of the organic electroluminescent device of the present application, in the light-emitting layer, the mass percentage content of the organic material is 0.5% to 5%. In this case, when the added mass percentage content of the organic material in the light-emitting layer of the organic electroluminescent device is 0.5% to 5%, the optoelectronic properties of the device can be improved.

[0046] As some possible implementation manners of the organic electroluminescent device of the present application, the light-emitting layer further contains at least one organic light-emitting material in compound BH

[0047] As some possible implementation manners of the organic electroluminescent device of the present application, a hole functional layer is further disposed between the anode and the light-emitting layer of the organic electroluminescent device, and an electron functional layer is further disposed between the light-emitting layer and the cathode. In this case, by simultaneously disposing the hole functional layer and the electron functional layer, the holes generated by the anode and the electrons generated by the cathode of the organic electroluminescent device are improved in migration and transport to the light-emitting layer. Excitons are formed by the recombination of electrons and holes, and light is emitted when the excitons transition back to the ground state, thereby improving the photoelectric conversion efficiency of the organic electroluminescent device.

[0048] As some possible implementation manners of the organic electroluminescent device of the present application, along the direction from the anode to the light-emitting layer, the hole functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer. In this case, the hole injection layer is used to improve the hole injection efficiency; the hole transport layer is used to increase the transport performance of holes and reduce the energy level difference between holes and other layers; the electron blocking layer is located between the light-emitting layer and the hole transport layer and is used to prevent electrons from entering the hole transport layer through the light-emitting layer, so as to improve the device efficiency.

[0049] As some possible implementation manners of the organic electroluminescent device of the present application, along the direction from the cathode to the light-emitting layer, the electron functional layer includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer. In this case, the electron injection layer is used to improve the electron injection efficiency and increase the contact area between electrons and other layers; the electron transport layer is used to increase the transport performance of electrons and reduce the energy level difference between electrons and other layers; the hole blocking layer is located between the light-emitting layer and the electron transport layer and is used to prevent holes from entering the electron transport layer through the light-emitting layer, so as to improve the device efficiency.

[0050] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the hole injection layer includes compound PD Compound HT-1 At least one of 3,4-ethylenedioxythiophene and polyaniline. In this case, these materials can all improve the hole injection efficiency.

[0051] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the hole transport layer includes compound HT-1 At least one of N,N'-diphenanthryl-N,N'-diphenylbenzidine and 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline]. In this case, these materials can all increase the transport performance of holes and reduce the energy level difference between holes and other layers.

[0052] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the electron blocking layer includes compound HT-2 At least one of 4,7-bis(trimethyl)-2-(2-phenyl)-benzotriazole-5-(4-pyrenyl) phenanthrene and 2,9-dibutyl docosyl bisthiophene. In this case, these materials can prevent electrons from entering the hole transport layer through the light-emitting layer to improve the device efficiency.

[0053] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the electron injection layer includes at least one of Yb, lithium cobalt fluoride, and triphenylamine;

[0054] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the electron transport layer includes compound ET-2 Compound LiQ At least one of 2,9-diisobutyl docosyl bisulfone and triphenylamine. In this case, these materials can increase the electron transport performance and reduce the energy level difference between electrons and other layers.

[0055] As some possible implementation manners of the organic electroluminescent device of the present application, the material of the hole blocking layer includes compound ET-1 At least one of 4,4'-bis(N-pyrazinyl) biphenyl and lithium cobalt fluoride. In this case, these materials can prevent holes from entering the electron transport layer through the light-emitting layer to improve the device efficiency.

[0056] Fourth aspect, the present application provides an optoelectronic device including the above-mentioned organic electroluminescent device.

[0057] In this way, the optoelectronic device provided by the present application, due to including the above-mentioned organic electroluminescent device, which has characteristics such as self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high responsiveness, thus improves the optoelectronic performance, use stability, and service life of the optoelectronic device.

[0058] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present application more obvious and understandable, the specific implementation manners of the present application are specifically exemplified below. Description of the Drawings

[0059] Figure 1 It is a schematic diagram of the normal structure of the organic electroluminescent device provided by the embodiment of the present application;

[0060] Figure 2 It is a schematic diagram of the inverted structure of the organic electroluminescent device provided by the embodiment of the present application;

[0061] Figure 3It is a schematic diagram of the synthesis of Compound 1 provided in Example 1 of this application;

[0062] Figure 4 It is the mass spectrum of Compound 1 provided in Example 1 of this application;

[0063] Figure 5 It is a schematic diagram of the synthesis of Compound 2 provided in Example 2 of this application;

[0064] Figure 6 It is the mass spectrum of Compound 1 provided in Example 2 of this application;

[0065] Figure 7 It is a schematic diagram of the synthesis of Compound 3 provided in Example 3 of this application;

[0066] Figure 8 It is the mass spectrum of Compound 1 provided in Example 3 of this application;

[0067] Figure 9 It is a schematic diagram of the synthesis of Compound 4 provided in Example 4 of this application;

[0068] Figure 10 It is the mass spectrum of Compound 1 provided in Example 4 of this application;

[0069] Figure 11 It is the spectrum of Compound 1 provided in Example 1 of this application;

[0070] Figure 12 It is the spectrum of Compound 2 provided in Example 1 of this application;

[0071] Figure 13 It is the spectrum of Compound 3 provided in Example 1 of this application;

[0072] Figure 14 It is the spectrum of Compound 4 provided in Example 1 of this application. Detailed implementation manners

[0073] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the following further elaborates on this application in combination with examples. It should be understood that the specific examples described here are only used to explain this application and are not used to limit this application.

[0074] In this application, the term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0075] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can each be single or multiple.

[0076] It should be understood that in various embodiments of this application, the magnitudes of the serial numbers of the above processes do not imply the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0077] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0078] The term "OLED" is an abbreviation for "Organic Light Emitting Diode", which represents an organic electroluminescent diode, also known as organic electroluminescent display, organic light emitting semiconductor (Organic Electroluminescence Display, OLED). OLED belongs to a current-type organic light emitting device, and is a phenomenon of luminescence caused by the injection and recombination of carriers. The luminescence intensity is proportional to the injected current. Under the action of an electric field, the holes generated at the anode and the electrons generated at the cathode will move, and are respectively injected into the hole transport layer and the electron transport layer, and migrate to the light emitting layer. When the two meet in the light emitting layer, energy excitons are generated, which excite the luminescent molecules to finally generate visible light.

[0079] The term "TADF" is an abbreviation for "Thermally Activated Delayed Fluorescence", which represents thermally activated delayed fluorescence. Its essence is that when the energy of the triplet excited state is close to that of the singlet excited state, the triplet excited state can undergo thermally activated reverse intersystem crossing to the singlet excited state through thermal activation. Traditional luminescence is fluorescence and phosphorescence, where excitons in the singlet state and triplet state return to the ground state in the form of radiative luminescence. Moreover, generally, the energy level difference between the lower singlet state and the lower triplet state is relatively large, resulting in the fact that once the exciton reaches the triplet state from the singlet state through the intersystem crossing (ISC) process, it cannot return to the singlet state.

[0080] The term "FWHM" is an abbreviation for "Full Width at Half Maximum", which represents the full width at half maximum, also known as half width, peak half width, peak half width, region width, region half width, etc. It is a term in chromatographic analysis that refers to the peak width at half of the peak height, that is, a straight line parallel to the peak base is drawn through the midpoint of the peak height, and the distance between the two intersection points of this straight line and the two sides of the peak. It is represented by the symbol Y1 / 2 or 2△t1 / 2.

[0081] The term "PLQY" is an abbreviation for "Photoluminescence Quantum Yield", which represents the photoluminescence quantum yield, that is, the ratio of the number of fluorescent photons emitted by a fluorescent substance after absorbing light to the number of photons of the incident excitation light, and is used to characterize the luminescence efficiency of a sample.

[0082] The term "current efficiency" refers to the ratio of the luminance L to the current density J passing through the device at this luminance, and is usually represented by the symbol η = L / J.

[0083] The term "EQE" is an abbreviation for "External Quantum Efficiency", which represents the external quantum efficiency. When photons are incident on the surface of a photosensitive device, some photons will excite the photosensitive material to generate electron-hole pairs and form a current. The ratio of the collected electrons (after internal electron-hole recombination and other processes) to the number of all incident photons is called the external quantum efficiency. For a light-emitting diode, its external quantum efficiency is equal to the ratio of the number of photons emitted in the plane per unit time to the number of electron-hole pairs injected in the plane per unit time.

[0084] In the chemical structural formula, "*" represents the connection site. Exemplarily, it means that the substituted structural unit is connected to the main framework structural unit through this * site.

[0085] The term "alkyl" refers to a straight-chain or branched-chain, monovalent, saturated aliphatic chain, including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl and other similar groups.

[0086] The term "aryl" refers to a cyclic aromatic hydrocarbon, including but not limited to phenyl, naphthyl, anthryl, phenanthryl and other similar groups.

[0087] The term "heteroaryl" refers to a monocyclic, polycyclic or fused polycyclic aromatic hydrocarbon in which one or more carbon atoms have been replaced by heteroatoms such as nitrogen, oxygen or sulfur. If the heteroaryl contains more than one heteroatom, these heteroatoms may be the same or different. Heteroaryls include, but are not limited to, benzofuranyl, benzothiophenyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzopyranyl, furanyl, imidazolyl, indazolyl, indolizinyl, indolyl, isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthyridinyl, oxadiazolyl, oxazinyl, oxazolyl, phthalazinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolyl, pyridazinyl, pyrido[3,4-b]indolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, thiadiazolyl, thiotriazolyl, thiazolyl, thienyl, triazinyl, triazolyl, xanthenyl and other similar groups.

[0088] The term "fused polycyclic group" refers to an aryl group formed by the fusion of two or more aromatic rings, where each aromatic ring shares at least two carbon atoms with at least one other aromatic ring. Common fused polycyclic groups include naphthyl, anthryl and phenanthryl, etc.

[0089] Currently, from the perspective of the development of the market situation, due to the diversity of organic semiconductor materials in chemical synthesis, relatively low manufacturing costs during large-scale production, and excellent optical and electrical properties, etc. Therefore, organic light-emitting diodes (OLEDs) based on organic semiconductor materials have great potential in various display intelligent terminal applications. Usually, an OLED device includes functional layers such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. When a voltage is applied between the two electrodes, holes are injected into the device from the anode, and electrons are injected into the device from the cathode. Under the action of the electric field, the holes generated by the anode and the electrons generated by the cathode will move, and are respectively injected into the hole transport layer and the electron transport layer, and migrate to the light-emitting layer. When the injected holes and electrons meet in the light-emitting layer, energy excitons are generated. When these excitons transition back to the ground state, photons with the same energy as the energy gap are emitted, thereby generating visible light. Currently, the light-emitting materials used in blue OLED devices are mostly traditional fluorescent molecules such as pyrene, anthracene, perylene, etc. The full width at half maximum (FWHM) of the emission spectra of these molecules is relatively wide, and it is difficult to achieve deep blue light in the display effect, which does not meet the requirements of high color rendering index display technology. Moreover, the efficiency of the devices using these materials is relatively low, which is not conducive to the realization of low-power consumption and long-service-life display devices.

[0090] In order to improve the color rendering index and luminous efficiency of blue-light organic materials and achieve the problem of display devices with low power consumption and long service life, it has been found through research that a class of boron-nitrogen ring compounds adopt multiple resonance effects in molecular design, that is, the molecular structure is maintained within a special planar rigid conjugated structure, and the different electronegativities brought by the empty orbitals on the boron atom that can participate in the electron cloud conjugation and the lone pair electrons on the nitrogen atom that can participate in the electron cloud conjugation are enhanced through the conjugation effect with each other, thereby forming an intramolecular short-range charge transfer state and realizing efficient luminescence with thermally activated delayed fluorescence (TADF) phenomenon. Moreover, compared with other luminescent materials, the characteristic of this planar structure lies in the high degeneracy of the energy levels of the molecular vibration modes, which makes the full width at half maximum (FWHM) of its emission spectrum significantly narrower than that of other types of luminescent materials, facilitating the achievement of high color purity. In recent years, due to the fact that this class of materials combines the high device efficiency of TADF materials, the high color purity of fluorescent materials, and potentially high device stability, this class of materials has received great attention from the academic and industrial circles and is a research hotspot in the field of OLED luminescent materials. However, based on the existing reports, there is still room for further improvement in achieving higher luminous efficiency, narrower FWHM, and longer device operating life for such luminescent materials.

[0091] For classical boron-nitrogen system materials, the size of the FWHM of their emission spectrum and the level of luminous efficiency often depend on whether the vibration and rotational degrees of freedom of the internal groups of the molecule can be effectively suppressed. For classical boron-nitrogen materials, the phenyl group connected to the nitrogen atom has a large torsional angle with the boron-nitrogen rigid conjugated plane and does not directly participate in the super-resonance effect of the boron-nitrogen rigid conjugated plane, and is regarded as a group that does not directly participate in the luminescence process of boron-nitrogen materials. However, such phenyl groups often have large vibration and rotational degrees of freedom and are considered an unfavorable factor for narrowing the FWHM of the emission spectrum. Therefore, in order to further narrow the FWHM of the emission spectrum of boron-nitrogen materials, the existing reports often adopt the method of fixing the phenyl group by constructing carbon-carbon single bonds to make it a part of the boron-nitrogen rigid conjugated plane. This technical solution can effectively reduce the FWHM of the material's emission spectrum, and the fewer free phenyl groups, the smaller the FWHM. However, when the phenyl group is incorporated into the boron-nitrogen rigid conjugated plane, the phenyl group will not only extend the conjugation length of the overall molecule, but the electron cloud on the phenyl group will also participate in the overall super-resonance effect of the molecule, resulting in a certain degree of red shift of the material's spectrum compared with the original boron-nitrogen material. This is also not conducive to the realization of blue-light OLED display devices with high color rendering index. And limited by the conjugation length of commonly used arylamines, the red shift brought by this technical solution is not sufficient to adjust the light color to the blue-light region, and it is also impossible to realize blue-light OLED display devices with high color rendering index.

[0092] In other reported technologies, there is also an effect of adjusting the emission color of the material and narrowing the full width at half maximum (FHWM) of the emission spectrum by substituting hydrogen atoms with arylamine groups at specific sites of the boron nitride material. This is because the introduction of arylamine can effectively adjust the frontier orbital energy levels of the material and regulate the intensity of the multiple resonance effect of the boron nitride rigid conjugated plane through the electron-donating ability of arylamine, thereby adjusting the emission color and narrowing the FHWM of the emission spectrum. The arylamine groups most commonly used to modify boron nitride materials currently are diphenylamine and its derivatives. Although the modification of boron nitride materials with diphenylamine can achieve the adjustment of emission color and the narrowing of the FHWM of the emission spectrum, due to the relatively low molecular rigidity of the diphenylamine group itself and the existence of certain rotational and vibrational degrees of freedom, the improvement ability for emission color and FHWM is relatively limited, and there is room for improvement.

[0093] Based on the above considerations, in order to further improve the emission color and FHWM of blue-light organic materials, solve the problems of improving the emission color adjustment performance and luminous efficiency, and realize a blue-light OLED display device with low power consumption and long service life. After in-depth research, an organic material is proposed, which is based on the boron nitride skeleton unit of the following formula (I) and introduces at least one of the following substitution structural units of formula (II-1) and / or formula (II-2) to form a new organic material.

[0094] In such an organic material, on the basis of the boron nitride skeleton, the introduced substitution structural unit is a brand-new rigid polycyclic arylamine unit, thus constructing a brand-new boron nitride-like skeleton. Among them, the polycyclic arylamine unit with a fused-ring structure introduced has high rigidity, effectively reducing the number of freely rotating phenyl groups in the organic material, which is beneficial to narrowing the FHWM of the emission of the organic material. The organic material constructed by the boron nitride-like skeleton unit and the substitution unit is a blue-light material with high molecular rigidity. Through the modification of the boron nitride-like skeleton by the high-rigidity polycyclic arylamine of the substitution structural unit, the emission color of the organic material can be flexibly adjusted, and the photoluminescence quantum yield of the organic material is improved.

[0095] For the convenience of understanding, the present application is specifically described through the following embodiments. It should be understood that the following embodiments are only used to further illustrate the solution of the present application and are not used to limit the scope of the present application.

[0096] In the first aspect, an embodiment of the present application provides an organic material, including the following boron nitride-like skeleton unit of formula (I) and substitution structural units of formula (II-1) and / or formula (II-2), and at least one substitution structural unit forms a substitution bond with at least one ring structure in the boron nitride-like skeleton unit;

[0097] Among them, ring A, ring B, and ring C are each independently selected from one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; X is selected from B, N, P, P═O, or Al; Y and Z are each independently selected from C═O, N-R3, O, S, Se, P, P═O, or P═S; R1, R2, and R3 are each independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al.

[0098] Thus, for the organic material provided in the embodiment of the present application, the adopted backbone structure is a boron nitride-like structure. A polycyclic aromatic amine unit with a fused ring structure is introduced as a substituted structural unit on at least one ring structure in the boron nitride-like backbone unit. This substituted structural unit has high rigidity. After introducing the high-rigidity polycyclic aromatic amine unit into the boron nitride-like backbone unit, the number of phenyl groups that can freely rotate within the molecule can be effectively reduced, and the vibration and rotational degrees of freedom of the internal groups of the molecule can be inhibited, thereby effectively narrowing the full width at half maximum (FHWM) of the luminescence of the organic material and improving the luminescence efficiency and color purity of the material. Through the flexible modification of the boron nitride-like backbone by the high-rigidity polycyclic aromatic amine of the substituted structural unit, the constructed organic material narrows the luminescence FWHM, enables flexible adjustment of the light color, improves the photoluminescence quantum yield, and better meets the application requirements of optoelectronic devices for organic materials with high color rendering index and high reduction degree of luminescence.

[0099] The organic material constructed by the boron nitride-like backbone unit and the substituted unit in the embodiment of the present application is a boron nitride-like organic light-emitting material with high molecular rigidity, and further is a blue light organic material. Through the flexible modification of the boron nitride-like backbone by the high-rigidity polycyclic aromatic amine of the substituted structural unit, the luminescence FWHM is narrowed, flexible adjustment of the light color is achieved, the color rendering index, luminescence efficiency, and color purity of the blue light organic material are improved, and the application requirements of optoelectronic devices such as blue light OLEDs can be better met.

[0100] The polycyclic aromatic amine substitution unit with a fused ring structure in the embodiment of the present application can be arbitrarily substituted on ring A, ring B, or ring C of the boron nitride-like backbone, or can be simultaneously substituted on two or three of rings A, B, and C of the boron nitride-like backbone. By adjusting the substitution position and substitution quantity of the polycyclic aromatic amine unit with a fused ring structure on the boron nitride-like backbone unit, flexible adjustment of the light color performance of the organic material can be realized. On the premise of improving the blue light color rendering index, luminescence efficiency, and color purity of the organic material, the organic material can better meet the application requirements of optoelectronic devices such as blue light OLEDs. In some possible implementation manners, the organic material includes at least one of the following formulas (III), (IV), (V), and (VI);

[0101]

[0102] In this case, for the organic materials with the configurations of the above formulas (III), (IV), (V), (VI), etc., through the modification of the boron-nitrogen-like framework by the highly rigid polycyclic aromatic amine of the substituted structural unit, the organic materials have a narrower FHWM, improving the performance such as the luminescence efficiency and color purity of the organic materials.

[0103] In some possible embodiments, in the boron-nitrogen-like framework unit, the A ring, the B ring, and the C ring are each independently selected from one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted fused ring group; X is selected from B, N, P, P=O, or Al; Y and Z are each independently selected from C=O, N-R3, O, S, Se, P, P=O, or P=S; and R3 is selected from one of a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted fused ring group. In this case, the formed boron-nitrogen-like framework unit is conducive to ensuring the optical properties of the organic materials.

[0104] In some possible embodiments, in the polycyclic aromatic amine substituted structural unit of the fused ring structure, R1 and R2 are selected from one of a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted fused ring group; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al. In this case, the formed polycyclic aromatic amine substituted structural unit has better molecular rigidity. Introduced into the boron-nitrogen-like framework unit, it can better adjust the light color of the organic material, narrow the luminescence FHWM, and improve the luminescence efficiency and color purity of the material.

[0105] In some possible embodiments, among the substituted or unsubstituted aryl group, the substituted or unsubstituted heteroaryl group, and the substituted or unsubstituted fused ring group, the aryl group includes but is not limited to phenyl, naphthyl, anthryl, phenanthryl, and other similar groups. The heteroaryl group includes but is not limited to benzofuranyl, benzothiophenyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzopyranyl, furanyl, imidazolyl, indazolyl, indazinyl, indolyl, isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthyridinyl, oxadiazolyl, oxazinyl, oxazolyl, phthalazinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolyl, pyridazinyl, pyrido[3,4-b]indolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, thiadiazolyl, thiotriazolyl, thiazolyl, thiophenyl, triazinyl, triazolyl, xanthenyl, and other similar groups. The fused ring group includes naphthyl, anthryl, phenanthryl, etc.

[0106] In some possible embodiments, X is selected from B. In this case, the boron-nitrogen-like framework unit in the organic material contains boron element.

[0107] In some possible embodiments, at least one of Y and Z is selected from N. In this case, the boron-nitrogen-like framework unit in the organic material contains nitrogen element.

[0108] In some possible embodiments, X is selected from B, and at least one of Y and Z is selected from N. In this case, the boron-nitrogen-like framework unit in the organic material contains both boron element and nitrogen element. At this time, the framework structure is a boron-nitrogen cyclized structure. This type of material has a multiple resonance effect in molecular design and can achieve efficient luminescence with thermally activated delayed fluorescence (TADF) phenomenon. It is beneficial to reduce the width of the full width at half maximum (FWHM) of the emission spectrum and improve the luminescence efficiency and color purity of the organic material.

[0109] In some possible embodiments, Y and Z are selected from the same element. Exemplarily, both Y and Z are N. In this case, the boron-nitrogen cyclized structure in the framework structure is more conducive to improving the optoelectronic properties of the organic material.

[0110] In some possible embodiments, ring A and ring B are each independently selected from a substituted aryl group, a substituted heteroaryl group, and a substituted fused ring group. In this case, the selection of ring A, ring B, and ring C in the boron-nitrogen-like framework unit will affect the optical properties of the constructed organic material to a certain extent. When ring A and ring B are each independently selected from a substituted aryl group, a substituted heteroaryl group, and a substituted fused ring group, the formed boron-nitrogen-like framework unit and the polycyclic aromatic amine substitution unit with a fused ring structure construct an organic material, which is beneficial to reducing the width of the FWHM of the emission spectrum of the organic material and improving the luminescence efficiency and color purity of the organic material.

[0111] In some possible embodiments, ring C is selected from an aryl group. In some specific embodiments, ring A and ring B are each independently selected from a substituted aryl group, a substituted heteroaryl group, and a substituted fused ring group, and ring C is selected from an aryl group. In this case, since ring C is selected from an aryl group, the polycyclic aromatic amine unit with a fused ring structure can easily be bonded to ring C through substitution, increasing the rigidity within the organic material molecule, reducing the width of the FWHM of the emission spectrum of the organic material, and improving the luminescence efficiency and color purity of the organic material.

[0112] In some possible embodiments, at least one of W1 or V1 is selected from N, or at least one of W2 or V2 is selected from N. In this case, the nitrogen atom can form a covalent bond with other atoms, enabling the compound to form a dense aromatic ring structure. Moreover, the nitrogen atom is more electronegative than the boron atom. Therefore, the nitrogen atom in the boron-nitrogen heteroaromatic fused ring compound can increase the charge and polarity of the entire molecule through conjugation. In addition, the electron cloud overlap and hybridization between the boron and nitrogen atoms can regulate the optical, electrical, and chemical properties of the boron-nitrogen heteroaromatic fused ring compound. By adjusting the position of the nitrogen atom and the introduction of substituents, characteristics such as the fluorescence emission intensity and spectral absorption position of the molecule can be changed.

[0113] In some possible embodiments, W1 and V1 are selected from the same element, or W2 and V2 are selected from the same element. In some specific embodiments, W1 and V1 are both N elements at the same time, or W2 and V2 are both N elements at the same time. In this case, it is more conducive to increasing the overall charge of the organic material molecules and adjusting the molecular properties.

[0114] In some possible embodiments, the organic material includes

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] at least one of; wherein, each time D appears, it is independently selected from one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted fused ring structure, a substituted or unsubstituted alkyl group, and hydrogen. In this case, these organic materials are blue light materials with high molecular rigidity. Through the flexible modification of the boron-nitrogen-like framework by the highly rigid polycyclic aromatic amine of the substituted structural unit, the emission FWHM is narrowed, the light color can be flexibly adjusted, the color rendering index, luminous efficiency and color purity of the blue light organic material are improved, and the application requirements of optoelectronic devices such as blue light OLEDs can be better met.

[0131] The organic material provided in the above embodiments of the present application can be prepared by the following example methods.

[0132] In a second aspect, an embodiment of the present application provides a method for preparing an organic material, including the following steps:

[0133] S10. Connect at least one substitution structural unit in the following formula (II-1) and / or formula (II-2) to at least one ring structure in the boron-nitrogen skeleton unit of formula (I) through a substitution reaction to obtain an organic material;

[0134] Wherein, ring A, ring B, and ring C are each independently selected from one of substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, and substituted or unsubstituted fused ring groups; X is selected from B, N, P, P=O, or Al; Y and Z are each independently selected from C=O, N-R3, O, S, Se, P, P=O, or P=S; R1, R2, and R3 are selected from one of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, and substituted or unsubstituted fused ring groups; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al.

[0135] In this way, in the method for preparing the organic material according to the embodiment of the present application, at least one polycyclic aromatic amine substitution structural unit having a fused ring structure is connected to at least one ring structure in the boron-nitrogen skeleton unit through a substitution reaction to construct a new organic material. Among them, the substitution structural unit has high rigidity. After the high-rigidity polycyclic aromatic amine unit is bonded to the boron-nitrogen skeleton unit through a substitution reaction, the number of phenyl groups that can freely rotate within the molecule can be effectively reduced, thereby effectively inhibiting the vibration and rotational freedom of the internal groups of the newly constructed organic material molecule, narrowing the emission FHWM of the organic material, and improving the emission efficiency and color purity of the material.

[0136] In some possible implementation manners, the organic material includes Compound 1 Compound 2 Compound 3 Compound 4 At least one of them. In this case, these organic materials of Compound 1 to Compound 4 are blue light materials with high molecular rigidity. Through the flexible modification of the boron-nitrogen skeleton by the substitution structural unit of high-rigidity polycyclic aromatic amine, the emission FWHM is narrowed, the light color can be flexibly adjusted, the color rendering index, emission efficiency, and color purity of the blue light organic material are improved, and the application requirements of optoelectronic devices such as blue light OLED can be better met.

[0137] In some possible implementation manners, the preparation of the above Compound 1 to Compound 4 includes the following steps:

[0138] S11. Prepare intermediate 1 by the first substitution reaction using 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole.

[0139] S12. Carry out the second substitution reaction on intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine to obtain intermediate 2.

[0140] S13. Carry out the third substitution reaction on intermediate 2 and 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine to obtain intermediate 3 respectively. Intermediate 3 includes intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4.

[0141] S14. Carry out substitution cyclization reactions on intermediate 3 respectively to obtain compound 1, compound 2, compound 3 or compound 4.

[0142] In the embodiment of the present application, 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole are used as raw materials to prepare intermediate 1 through the first substitution reaction. Intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine further undergo the second substitution reaction to obtain intermediate 2. Intermediate 2 is respectively subjected to substitution reactions with 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine, and intermediate 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 can be obtained respectively. Then, substitution cyclization reactions are carried out on each intermediate 3 to form boron-nitrogen heteroaromatic fused ring compounds, and compound 1, compound 2, compound 3 or compound 4 are obtained respectively.

[0143] In some possible embodiments, in the above step S11, the temperature condition of the first substitution reaction is 80°C to 120°C, and the reaction duration is 6 h to 10 h. Under this reaction condition, it is beneficial for the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole to generate intermediate 1. Exemplarily, the temperature condition of the first substitution reaction can typically but non-restrictively be 80°C to 90°C, 90°C to 100°C, 100°C to 110°C, 110°C to 120°C, etc., and the reaction duration can typically but non-restrictively be 6 h to 7h, 7h to 8h, 8h to 9h, 9h to 10 h, etc.

[0144] In some possible embodiments, the catalyst for the first substitution reaction includes at least one of cesium carbonate anhydrous, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide. Under the conditions of these catalysts, it is beneficial to catalyze the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole to generate intermediate 1, improve the product purity, and increase the yield.

[0145] In some possible embodiments, the solvent for the first substitution reaction includes at least one of N,N-dimethylformamide, tetrahydrofuran, 2-methyltetrahydrofuran, acetone, 1,4-dioxane, acetonitrile, diethylene glycol dimethyl ether, toluene, and dichloromethane. In this case, these solvents have good solubility for both 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole, provide a solution environment for the substitution reaction between 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole, and are beneficial for the substitution reaction to proceed and generate intermediate 1.

[0146] In some specific embodiments, 2,6-difluoro-4-bromo-chlorobenzene, 3,6-di-tert-butylcarbazole, and cesium carbonate anhydrous with a mass ratio of (80 - 120):(60 - 85):(160 - 180) are dissolved in a solvent such as anhydrous N,N-dimethylformamide, heated to 80°C to 120°C, and stirred for 6 h to 10 h. After cooling the reaction solution to room temperature, a large amount of deionized water and dichloromethane are added for extraction, and the organic phase is retained. After removing the organic solvent by vacuum distillation, it is purified by silica gel column chromatography to obtain intermediate 1.

[0147] In some possible embodiments, in the above step S12, the second substitution reaction is carried out under stirring conditions heated to reflux for 12 h to 24h. Under this condition, intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine undergo a second substitution reaction to generate intermediate 2. Exemplarily, the reaction duration of the second substitution reaction can typically but non-restrictively be 12h to 15h, 15h to 18h, 18h to 20h, 20h to 22h, 22h to 24 h, etc.

[0148] In some possible embodiments, the catalyst for the second substitution reaction includes at least one of cesium carbonate anhydrous, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide. Under the conditions of these catalysts, it is beneficial to catalyze the substitution reaction between intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine to generate intermediate 2, improving the product purity and yield.

[0149] In some possible embodiments, the solvent for the second substitution reaction includes at least one of diphenyl ether and dibenzyl ether. In this case, these solvents have good solubility for both intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine, providing a solution environment for the substitution reaction between intermediate 1 and 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine, which is beneficial for the substitution reaction to proceed and generate intermediate 2.

[0150] In some specific examples, intermediate 1, 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine, and cesium carbonate anhydrous with a mass ratio of (80 - 120):(70 - 100):(160 - 180) are dissolved in a solvent such as diphenyl ether, heated to reflux, and stirred overnight. After cooling the reaction solution to room temperature, a large amount of deionized water and dichloromethane are added for extraction, and the organic phase is retained. After removing the organic solvent by vacuum distillation, it is purified by silica gel column chromatography to obtain intermediate 2.

[0151] In some possible embodiments, in the above step S13, the third substitution reaction is carried out under stirring conditions at reflux temperature for 12 h to 24 h. Under this condition, intermediate 2 undergoes a third substitution reaction with 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine, or 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine to generate intermediates 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3, or intermediate 3-4 respectively. Exemplarily, the reaction duration of the third substitution reaction can typically but not restrictively be 12 h - 15 h, 15 h - 18 h, 18 h - 20 h, 20 h - 22 h, 22 h - 24 h, etc.

[0152] In some possible embodiments, the catalyst for the third substitution reaction includes tris(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and anhydrous sodium tert-butoxide. Under the conditions of these catalysts, it is favorable to catalyze the substitution reaction between intermediate 2 and 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine to generate intermediate 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4, respectively.

[0153] In some possible embodiments, the solvent for the third substitution reaction includes at least one of toluene, benzene, chlorobenzene, tetrahydrofuran, diethylene glycol dimethyl ether, and dichloromethane. Under these solvent conditions, these solvents have good solubility for intermediate 2 and 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine or 1-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine, providing a solution environment for the substitution reaction, which is conducive to the generation of intermediate 3.

[0154] In some specific embodiments, intermediate 2,6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine / 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine / 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine / 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine with a mass ratio of (80 - 120):(25 - 55):(3 - 4):(4 - 5):(20 - 30), tris(dibenzylideneacetone)dipalladium, tert-butylphosphine tetrafluoroborate and anhydrous sodium tert-butoxide are dissolved in a solvent such as toluene, heated to reflux and stirred overnight. After cooling the reaction solution to room temperature, a large amount of deionized water and dichloromethane are added for extraction, and the organic phase is retained. After removing the organic solvent by vacuum distillation, purification is carried out by silica gel column chromatography to obtain intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 respectively. Among them, when 2,6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine is used as the raw material, intermediate 3-1 is obtained; when 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine is used as the raw material, intermediate 3-2 is obtained; when 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine is used as the raw material, intermediate 3-3 is obtained; when 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine is used as the raw material, intermediate 3-4 is obtained.

[0155] In some possible embodiments, in the above step S14, the steps of the substitution cyclization reaction include: dissolving intermediate 3 in an organic solvent, and then dropwise adding a lithium reagent under the condition that the temperature is not higher than 10°C, heating to 80°C - 120°C and reacting for 1 h - 3 h; cooling to a temperature not higher than 10°C and dropwise adding a boron source, heating to 160°C - 200°C and reacting for 6 h - 10 h; cooling to a temperature not higher than 10°C and dropwise adding N,N-diisopropylethylamine, heating to 160°C - 200°C and reacting for 12 h - 24 h; and separating to obtain an organic material. Under such reaction conditions, it is beneficial for intermediate 3 such as intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 to carry out substitution cyclization reactions respectively to form boron-nitrogen heteroaromatic fused-ring compounds, and to obtain compound 1, compound 2, compound 3 or compound 4 respectively. Exemplarily, the condition that the temperature is not higher than 10°C may be an ice bath condition. The temperature for heating the reaction after dropwise adding the lithium reagent is typically but not limited to 80°C - 90°C, 90°C - 100°C, 100°C - 110°C, 110°C - 120°C, etc., and the reaction duration is typically but not limited to 1 h - 2 h, 2 h - 3 h, etc. The temperature for heating the reaction after dropwise adding the boron source is typically but not limited to 160°C - 170°C, 170°C - 180°C, 180°C - 190°C, 190°C - 200°C, etc., and the reaction duration is typically but not limited to 6 h - 7 h, 7 h - 8 h, 8 h - 9 h, 9 h - 10 h, etc. The temperature for heating the reaction after dropwise adding N,N-diisopropylethylamine is typically but not limited to 160°C - 170°C, 170°C - 180°C, 180°C - 190°C, 190°C - 200°C, etc., and the reaction duration is typically but not limited to 12 h - 15 h, 15 h - 18 h, 18 h - 20 h, 20 h - 22 h, 22 h - 24 h, etc.

[0156] In some possible embodiments, the organic solvent includes at least one of tert-butylbenzene. In this case, these organic solvents have good solubility for components such as intermediate 3, the lithium reagent, and the boron source, provide a solution environment for the reaction between the components, and are beneficial for obtaining compounds 1 - 4.

[0157] In some possible embodiments, the lithium reagent includes at least one of n-butyllithium, tert-butyllithium, and lithium diisopropylamide. In this case, these lithium reagents are all beneficial for intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 to carry out substitution cyclization reactions respectively to form boron-nitrogen heteroaromatic fused-ring compounds, and to obtain compound 1, compound 2, compound 3 or compound 4 respectively.

[0158] In some possible embodiments, the boron source includes at least one of boron tribromide. In this case, these boron sources are all beneficial to the substitution cyclization reactions of intermediate 3-1, intermediate 3-2, intermediate 3-3 or intermediate 3-4 respectively to form boron-nitrogen heteroaromatic fused ring compounds, and compounds 1, compound 2, compound 3 or compound 4 are obtained respectively.

[0159] In some specific embodiments, intermediate 3-1 / intermediate 3-2 / intermediate 3-3 / intermediate 3-4 (8 g to 12 g) is dissolved in an organic solvent such as tert-butylbenzene (200 mL to 400 mL), and a lithium reagent such as tert-butyllithium (10 mL to 20 mL, 1.3 M n-hexane solution) is added dropwise under an ice bath. After the addition is completed, the reaction solution is heated to 80 °C to 120 °C and stirred for 1 h to 3 h. Subsequently, the reaction solution is cooled to an ice bath, and a boron source such as boron tribromide (4 mL to 6 mL) is added dropwise. After the addition is completed, it is heated to 160 °C to 200 °C and stirred for 6 h to 10 h. Subsequently, N,N-diisopropylethylamine (24 mL) is added dropwise under an ice bath. After the addition is completed, it is heated to 160 °C to 200 °C and stirred for 12 h to 24 h, and stirred overnight. After the reaction solution is cooled to room temperature, a large amount of deionized water and dichloromethane are added for extraction, and the organic phase is retained. After the organic solvent is removed by vacuum distillation, it is purified by silica gel column chromatography to obtain compound 1, compound 2, compound 3 or compound 4. Among them, when intermediate 3-1 is used as the raw material, compound 1 is obtained; when intermediate 3-2 is used as the raw material, compound 2 is obtained; when intermediate 3-3 is used as the raw material, compound 3 is obtained; when intermediate 3-4 is used as the raw material, compound 4 is obtained.

[0160] In a third aspect, an organic electroluminescent device provided by an embodiment of the present application includes an anode, a cathode, and a light-emitting layer stacked between the anode and the cathode. The light-emitting layer contains the above-mentioned organic material or the organic material prepared by the above method.

[0161] The organic electroluminescence provided by the embodiment of the present application contains the above-mentioned organic material in the light-emitting layer between the anode and the cathode. The skeleton structure of the organic material is a boron-nitrogen-like structure, and the substitution structural unit introduced on at least one ring structure in the boron-nitrogen-like skeleton unit is a polycyclic aromatic amine unit with a fused ring structure. This substitution structural unit has high rigidity, can effectively reduce the number of phenyl groups rotating freely in the molecule, inhibit the vibration and rotational freedom of the internal groups of the molecule, effectively narrow the emission FHWM of the organic material, and improve the emission efficiency and color purity of the organic material. Therefore, the current efficiency, external quantum efficiency, photoelectric conversion efficiency, service life and other optoelectronic properties of the organic electroluminescent device are improved, so that the organic electroluminescent device has characteristics such as self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high responsiveness.

[0162] In some possible embodiments, in the light-emitting layer, the mass percentage content of the organic material is 0.5% to 5%. In this case, adding the organic material in the light-emitting layer of the organic electroluminescent device with a mass percentage content of 0.5% to 5% can improve the optoelectronic performance of the device. Exemplarily, the mass percentage content of the organic material in the light-emitting layer can typically but not restrictively be 0.5% to 0.6%, 0.6% to 0.7%, 0.7% to 0.8%, 0.8% to 1.0%, 1.0% to 1.5%, 1.5% to 2.0%, 2.0% to 3.0%, 3.0% to 4.0%, 4.0% to 5.0%, etc.

[0163] In some possible embodiments, the light-emitting layer further contains compound BH and at least one of the organic light-emitting materials in [compound BH]. In this case, these organic light-emitting materials contained simultaneously in the light-emitting layer of the organic electroluminescent device can better improve the optoelectronic performance of the organic electroluminescent device through the synergistic effect of two or more light-emitting materials.

[0164] In some possible embodiments, a hole function layer is further provided between the anode and the light-emitting layer of the organic electroluminescent device, and an electron function layer is further provided between the light-emitting layer and the cathode. In this case, a hole function layer is further provided between the anode and the light-emitting layer of the organic electroluminescent device, and this hole function layer (Hole Function Layer) is used to receive and transport holes (empty electron states) to the light-emitting layer. It is beneficial to promote the transport of holes inside the device and provide a sufficient contact area with the light-emitting material to increase the light-emitting efficiency. An electron function layer is provided between the light-emitting layer and the cathode, and this electron function layer (Electron Function Layer) is used to receive and transport negative electrons (electron states with excess electrons) to the light-emitting layer. It is beneficial to promote the transport of electrons inside the device and provide a sufficient contact area with the light-emitting material to increase the light-emitting efficiency. By simultaneously providing a hole function layer and an electron function layer, the holes generated by the anode and the electrons generated by the cathode of the organic electroluminescent device are improved in migration and transport to the light-emitting layer, and excitons are formed through the recombination of electrons and holes. When the excitons transition back to the ground state, light is emitted, thereby improving the optoelectronic conversion efficiency of the organic electroluminescent device.

[0165] In some possible embodiments, along the direction from the anode to the light-emitting layer, the hole functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer. In this case, the hole injection layer (Hole Injection Layer) is used to improve the hole injection efficiency. The hole transport layer (Hole Transport Layer) is used to increase the transport performance of holes and reduce the energy level difference between holes and other layers. The electron blocking layer is located between the light-emitting layer and the hole transport layer and is used to prevent electrons from entering the hole transport layer through the light-emitting layer to improve the device efficiency.

[0166] In some possible embodiments, the material of the hole injection layer includes compound PD Compound HT-1 At least one of 3,4-ethylenedioxythiophene (PEDOT) and polyaniline (PANI). In this case, these materials can all improve the hole injection efficiency.

[0167] In some possible embodiments, the material of the hole transport layer includes compound HT-1 At least one of N,N'-diphenanthryl-N,N'-diphenylbenzidine (NPB) and 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC). In this case, these materials can all increase the transport performance of holes and reduce the energy level difference between holes and other layers.

[0168] In some possible embodiments, the material of the electron blocking layer includes compound HT-2 At least one of 4,7-bis(trimethylsilyl)-2-(2-phenyl)-benzotriazole-5-(4-pyrenyl)ethynylphenylene (TPBI) and 2,9-didecylbenzo[1,2-b:4,5-b']dithiophene (DTS). In this case, these materials can all prevent electrons from entering the hole transport layer through the light-emitting layer to improve the device efficiency.

[0169] In some possible embodiments, along the direction from the cathode to the light-emitting layer, the electron functional layer includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer. In this case, the electron injection layer (Electron Injection Layer) is used to improve the electron injection efficiency and increase the contact area between electrons and other layers. The electron transport layer (Electron Transport Layer) is used to increase the transport performance of electrons and reduce the energy level difference between electrons and other layers. The hole blocking layer is located between the light-emitting layer and the electron transport layer and is used to prevent holes from entering the electron transport layer through the light-emitting layer to improve the device efficiency.

[0170] In some possible embodiments, the material of the electron injection layer includes at least one of Yb, lithium cobalt fluoride (LiF), and triphenylamine (TPD). In this case, these materials can all improve the electron injection efficiency and increase the contact area between electrons and other layers.

[0171] In some possible embodiments, the material of the electron transport layer includes compound ET-2 Compound LiQ At least one of 2,9-diisobutyldocosyl bisulfone (DDM) and triphenylamine (TPD). In this case, these materials can all increase the transport performance of electrons and reduce the energy level difference between electrons and other layers.

[0172] In some possible embodiments, the material of the hole blocking layer includes compound ET-1 At least one of 4,4'-bis(N-pyrazinyl)biphenyl (PXZ) and cobalt fluoride (CoF). In this case, these materials can all prevent holes from entering the electron transport layer through the light-emitting layer to improve the device efficiency.

[0173] In the above embodiments of the present application, the organic electroluminescent device is not limited by the device structure and can be a device with a normal structure or an inverted structure.

[0174] In some possible embodiments, the normal-structure organic electroluminescent device includes a stacked structure of an anode and a cathode arranged opposite to each other, a light-emitting layer arranged between the anode and the cathode, and the anode is arranged on a substrate. Further, a hole injection layer, a hole transport layer, an electron blocking layer and other hole functional layers can be stacked between the anode and the light-emitting layer; an electron injection layer, an electron transport layer, a hole blocking layer and other electron functional layers can be stacked between the cathode and the light-emitting layer, as shown in the figure. In some specific embodiments of the normal-structure device, the optoelectronic device includes a substrate, an anode arranged on the surface of the substrate, a hole injection layer arranged on the surface of the anode, a hole transport layer arranged on the surface of the hole injection layer, an electron blocking layer arranged on the surface of the hole transport layer, a light-emitting layer arranged on the surface of the electron blocking layer, a hole blocking layer arranged on the surface of the light-emitting layer, an electron transport layer arranged on the surface of the hole blocking layer, an electron injection layer arranged on the surface of the electron transport layer, and a cathode arranged on the surface of the electron injection layer. Figure 1 In some specific embodiments of the normal-structure device, the optoelectronic device includes a substrate, an anode arranged on the surface of the substrate, a hole injection layer arranged on the surface of the anode, a hole transport layer arranged on the surface of the hole injection layer, an electron blocking layer arranged on the surface of the hole transport layer, a light-emitting layer arranged on the surface of the electron blocking layer, a hole blocking layer arranged on the surface of the light-emitting layer, an electron transport layer arranged on the surface of the hole blocking layer, an electron injection layer arranged on the surface of the electron transport layer, and a cathode arranged on the surface of the electron injection layer.

[0175] In some other possible embodiments, the inverted-structure organic electroluminescent device includes a stacked structure of an anode and a cathode disposed opposite to each other, a light-emitting layer disposed between the anode and the cathode, and the cathode is disposed on a substrate. Further, hole-functional layers such as a hole injection layer, a hole transport layer, and an electron blocking layer may be disposed between the anode and the light-emitting layer; electron-functional layers such as an electron injection layer, an electron transport layer, and a hole blocking layer may be disposed between the cathode and the light-emitting layer, as shown in the appended Figure 2 figure. In some embodiments of the inverted-structure device, the optoelectronic device includes a substrate, a cathode disposed on the surface of the substrate, an electron injection layer disposed on the surface of the cathode, an electron transport layer disposed on the surface of the electron injection layer, a hole blocking layer disposed on the surface of the electron transport layer, a light-emitting layer disposed on the surface of the hole blocking layer, an electron blocking layer disposed on the surface of the light-emitting layer, a hole transport layer disposed on the surface of the electron blocking layer, a hole injection layer disposed on the surface of the hole transport layer, and an anode disposed on the surface of the hole injection layer.

[0176] In some possible embodiments, in the organic electroluminescent device, the selection of the substrate is not limited, and a rigid substrate or a flexible substrate can be used. In some specific embodiments, the rigid substrate includes, but is not limited to, one or more of glass and metal foils. In some specific embodiments, the flexible substrate includes, but is not limited to, one or more of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polystyrene (PS), polyethersulfone (PES), polycarbonate (PC), polyarylate (PAT), polyaryl ester (PAR), polyimide (PI), polyvinyl chloride (PV), polyethylene (PE), polyvinylpyrrolidone (PVP), and textile fibers.

[0177] In some possible embodiments, in the organic electroluminescent device, the material selection of the anode is not limited and can be selected from doped metal oxides, including but not limited to one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), and aluminum-doped magnesium oxide (AMO). It can also be selected from composite electrodes with a metal sandwiched between doped or undoped transparent metal oxides, including but not limited to one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2.

[0178] In some possible embodiments, in an organic electroluminescent device, the material of the cathode can be one or more of various conductive carbon materials, conductive metal oxide materials, and metal materials. In some specific embodiments, the conductive carbon materials include, but are not limited to, doped or undoped carbon nanotubes, doped or undoped graphene, doped or undoped graphene oxide, C60, graphite, carbon fiber, porous carbon, or a mixture thereof. In some specific embodiments, the conductive metal oxide materials include, but are not limited to, ITO, FTO, ATO, AZO, or a mixture thereof. In some specific embodiments, the metal materials include, but are not limited to, Al, Ag, Cu, Mo, Au, or an alloy thereof; among the metal materials, the morphology includes, but is not limited to, a dense thin film, nanowire, nanosphere, nanorod, nanocone, nano-hollow sphere, or a mixture thereof; preferably, the cathode is Ag or Al.

[0179] In a fourth aspect, an embodiment of the present application provides an optoelectronic device including the above-mentioned organic electroluminescent device.

[0180] Thus, in the optoelectronic device provided by the embodiment of the present application, since it includes the above-mentioned organic electroluminescent device, and this organic electroluminescent device has characteristics such as self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high responsiveness, the optoelectronic performance, use stability, and service life of the optoelectronic device are improved.

[0181] In some possible embodiments, the optoelectronic device includes a display device and / or a lighting device.

[0182] In some embodiments, the optoelectronic device includes a display device. Organic electroluminescent devices such as OLEDs have been widely used in display devices. The display device includes a display screen. In this case, the organic materials in the above embodiments of the present application can be widely used in various terminal devices equipped with display screens such as OLEDs. Typically but not restrictively, they can be smartphones, tablet computers, personal laptop computers, smart TVs, in-vehicle displays, smart watches, etc.

[0183] In some embodiments, the optoelectronic device includes a lighting device. The application advantages of organic electroluminescent devices such as OLEDs in lighting devices mainly include: First, it can achieve full transparency with a light transmittance of up to 50%; second, it can achieve any shape, having the advantage of flexible application; in addition, it has advantages such as high efficiency, environmental protection, and safety.

[0184] Embodiment

[0185] The following is explained in conjunction with specific embodiments. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer of the reagents or instruments is not indicated, they are all conventional products that can be obtained commercially.

[0186] Example 1

[0187] The present invention provides an organic material, the chemical structure of which is shown in Compound 1.

[0188] The synthesis process is as follows Figure 3 As shown, the preparation steps include:

[0189] ① Dissolve 2,6-difluoro-4-bromo-chlorobenzene (100 g), 3,6-di-tert-butylcarbazole (72 g) and anhydrous cesium carbonate (170 g) in anhydrous N,N-dimethylformamide (500 mL), heat to 100 ° C and stir for 8 hours. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 101 g of intermediate 1 with a yield of 87%.

[0190] ② Dissolve intermediate 1 (100 g), 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophene-3-amine (85 g) and anhydrous cesium carbonate (170 g) in diphenyl ether (200 mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 105 g of intermediate 2 with a yield of 62%.

[0191] ③ Dissolve intermediate 2 (100g), 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine (38g), tri(dibenzylideneacetone)dipalladium (3.5g), tri-tert-butylphosphine tetrafluoroborate (4.5g) and anhydrous sodium tert-butoxide (25g) in toluene (500mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 86g of intermediate 3-1 with a yield of 75%.

[0192] ④ Dissolve intermediate 3-1 (10 g) in tert-butylbenzene (300 mL), and dropwise add tert-butyllithium (16 mL, 1.3 M n-hexane solution) under an ice bath. After the addition is complete, heat the reaction solution to 100 °C and stir for 2 hours. Subsequently, cool the reaction solution to an ice bath and dropwise add boron tribromide (5.2 mL). After the addition is complete, heat to 180 °C and stir for 8 hours. Subsequently, dropwise add N,N-diisopropylethylamine (24 mL) under an ice bath. After the addition is complete, heat to 180 °C and stir overnight. After cooling the reaction solution to room temperature, add a large amount of deionized water and dichloromethane for extraction, and retain the organic phase. After removing the organic solvent by vacuum distillation, purify by silica gel column chromatography to obtain 3.1 g of compound 1 with a yield of 30%. Product characterization: 1 H NMR (600 MHz, MethyleneChloride-d2) δ 8.69 (d, J = 1.9 Hz, 1H), 8.39 (d, J = 1.9 Hz, 1H), 8.29 (d, J = 2.1 Hz, 1H), 8.27 (d, J = 8.8 Hz, 1H), 7.90 (d, J = 8.4 Hz, 1H), 7.81 (s, 3H), 7.76 (s, 1H), 7.69 (d, J = 8.2 Hz, 1H), 7.65 (dd, J = 8.7, 2.1 Hz, 1H), 7.61–7.57 (m, 1H), 7.46 (d, J = 8.1 Hz, 2H), 7.42 (dd, J = 8.4, 1.8 Hz, 1H), 7.17 (dd, J = 8.5, 7.1 Hz, 2H), 6.66–6.60 (m, 2H), 6.45 (d, J = 8.1 Hz, 2H), 6.02 (s, 1H), 4.27 (q, J = 8.0 Hz, 1H), 3.71 (d, J = 11.9 Hz, 1H), 3.31 (dd, J = 9.4, 5.6 Hz, 1H), 3.28 (s, 1H), 3.23 (t, J = 8.9 Hz, 1H), 3.16 (dt, J = 9.4, 4.6 Hz, 2H), 3.07–3.00 (m, 1H), 2.42–2.37 (m, 1H), 1.84–1.78 (m, 1H), 1.66 (s, 9H), 1.51 (s, 9H), 1.23 (s, 8H), 1.05 (s, 9H). MS (ASAP) = 899.1. The mass spectrum is as attached Figure 4 as shown

[0193] Example 2

[0194] An organic material is provided in an embodiment of the present application, and its chemical structure is as shown in compound 2

[0195] The synthesis process is as attached Figure 5 as shown, and includes the following preparation steps:

[0196] ① Dissolve 2,6-difluoro-4-bromo-chlorobenzene (100 g), 3,6-di-tert-butylcarbazole (72 g) and anhydrous cesium carbonate (170 g) in anhydrous N,N-dimethylformamide (500 mL), heat to 100 ° C and stir for 8 hours. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 101 g of intermediate 1 with a yield of 87%.

[0197] ② Dissolve intermediate 1 (100 g), 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophene-3-amine (85 g) and anhydrous cesium carbonate (170 g) in diphenyl ether (200 mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 105 g of intermediate 2 with a yield of 62%.

[0198] ③ Dissolve intermediate 2 (100 g), 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine (38 g), tri(dibenzylideneacetone)dipalladium (3.5 g), tri-tert-butylphosphine tetrafluoroborate (4.5 g) and anhydrous sodium tert-butoxide (25 g) in toluene (500 mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, a large amount of deionized water and dichloromethane are added to extract, and the organic phase is retained. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 25 g of intermediate 3-2 with a yield of 22%.

[0199] ④ Dissolve the intermediate 3-2 (10g) in tert-butylbenzene (300mL), and add tert-butyl lithium (16mL, 1.3M n-hexane solution) dropwise under an ice bath. After the addition is complete, heat the reaction solution to 100°C and stir for 2 hours. Subsequently, cool the reaction solution to an ice bath and add boron tribromide (5.2mL). After the addition is complete, heat to 180°C and stir for 8 hours. Subsequently, add N,N-diisopropylethylamine (24mL) dropwise under an ice bath. After the addition is complete, heat to 180°C and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and extract with dichloromethane, and retain the organic phase. After removing the organic solvent by reduced pressure distillation, purify by silica gel column chromatography to obtain 2.1g of compound 2 with a yield of 21%. Product characterization: 11H NMR (600 MHz, MethyleneChloride-d2) δ 8.66 (d, J = 1.9 Hz, 1H), 8.36 (d, J = 1.9 Hz, 1H), 8.27 (d, J = 2.1 Hz, 1H), 8.25 (d, J = 8.8 Hz, 1H), 7.88 (d, J = 8.4 Hz, 1H), 7.71 (q, J = 8.0 Hz, 3H), 7.63 (dd, J = 8.7, 2.1 Hz, 1H), 7.45 (d, J = 7.9 Hz, 2H), 7.41 (dd, J = 8.4, 1.8 Hz, 1H), 7.31 (d, J = 1.7 Hz, 1H), 7.24 (t, J = 7.8 Hz, 2H), 6.96 (d, J = 8.1 Hz, 2H), 6.82 (t, J = 7.3 Hz, 1H), 6.60 (d, J = 1.8 Hz, 1H), 5.51 (s, 1H), 4.53 (q, J = 7.4 Hz, 1H), 3.51 (s, 1H), 3.42 (d, J = 12.2 Hz, 1H), 3.27 (s, 2H), 3.21 (s, 1H), 3.02–2.95 (m, 1H), 2.51 (s, 1H), 1.89 (d, J = 12.4 Hz, 1H), 1.84 (dq, J = 13.2, 4.2 Hz, 1H), 1.65 (s, 9H), 1.51 (s, 9H), 1.40 (s, 10H), 1.07 (s, 9H). MS (ASAP) = 899.1. The mass spectrum is as attached Figure 6 as shown

[0200] Example 3

[0201] The embodiment of the present application provides an organic material, whose chemical structure is as shown in Compound 3

[0202] The synthesis process is as attached Figure 7 as shown, and includes the following preparation steps:

[0203] ① Dissolve 2,6-difluoro-4-bromo-chlorobenzene (100 g), 3,6-di-tert-butylcarbazole (72 g) and cesium carbonate anhydrous (170 g) in anhydrous N,N-dimethylformamide (500 mL), heat to 100 °C and stir for 8 hours. After cooling the reaction solution to room temperature, add a large amount of deionized water and dichloromethane for extraction, and retain the organic phase. After removing the organic solvent by vacuum distillation, purify by silica gel column chromatography to obtain 101 g of Intermediate 1, with a yield of 87%.

[0204] ② Dissolve intermediate 1 (100 g), 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophene-3-amine (85 g) and anhydrous cesium carbonate (170 g) in diphenyl ether (200 mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 105 g of intermediate 2 with a yield of 62%.

[0205] ③ Dissolve intermediate 2 (100 g), 6-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine (38 g), tri(dibenzylideneacetone)dipalladium (3.5 g), tri-tert-butylphosphine tetrafluoroborate (4.5 g) and anhydrous sodium tert-butoxide (25 g) in toluene (500 mL), heat to reflux and stir overnight. After the reaction solution was cooled to room temperature, a large amount of deionized water and dichloromethane were added to extract, and the organic phase was retained. After the organic solvent was removed by reduced pressure distillation, it was purified by silica gel column chromatography to obtain 80 g of intermediate 3-3 with a yield of 70%.

[0206] ④ Dissolve the intermediate 3-3 (10g) in tert-butylbenzene (300mL), and add tert-butyl lithium (16mL, 1.3M n-hexane solution) dropwise under an ice bath. After the addition is complete, heat the reaction solution to 100°C and stir for 2 hours. Subsequently, cool the reaction solution to an ice bath and add boron tribromide (5.2mL). After the addition is complete, heat to 180°C and stir for 8 hours. Subsequently, add N,N-diisopropylethylamine (24mL) dropwise under an ice bath. After the addition is complete, heat to 180°C and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and extract with dichloromethane, and retain the organic phase. After removing the organic solvent by reduced pressure distillation, purify by silica gel column chromatography to obtain 3.5g of compound 3 with a yield of 29%. Product characterization: 11H NMR (600 MHz, MethyleneChloride-d2) δ 8.60 (d, J = 1.9 Hz, 1H), 8.31 (d, J = 1.9 Hz, 1H), 8.22–8.17 (m, 2H), 7.82 (d, J = 8.4 Hz, 1H), 7.69 (s, 1H), 7.63 (d, J = 7.9 Hz, 1H), 7.58 (dd, J = 8.8, 2.1 Hz, 1H), 7.51 (s, 1H), 7.40 (d, J = 8.4 Hz, 2H), 7.34 (dd, J = 8.4, 1.8 Hz, 1H), 7.14 (d, J = 8.5 Hz, 2H), 6.53 (d, J = 1.8 Hz, 1H), 6.33 (s, 2H), 5.96 (s, 1H), 4.17 (s, 1H), 3.68 (s, 1H), 3.21 (s, 2H), 3.15 (s, 1H), 3.11–3.05 (m, 2H), 2.97 (s, 1H), 2.32 (s, 1H), 1.83 (d, J = 13.0 Hz, 1H), 1.58 (s, 9H), 1.43 (s, 10H), 1.19 (s, 10H), 1.12 (s, 9H), 0.98 (s, 9H). MS (ASAP) = 955.2. The mass spectrum is as attached Figure 8 as shown.

[0207] Example 4

[0208] An organic material is provided in an embodiment of the present application, and its chemical structure is as shown in Compound 4

[0209] Its synthesis process is as attached Figure 9 as shown, and includes the following preparation steps:

[0210] ① Dissolve 2,6-difluoro-4-bromo-chlorobenzene (100 g), 3,6-di-tert-butylcarbazole (72 g) and cesium carbonate anhydrous (170 g) in anhydrous N,N-dimethylformamide (500 mL), heat to 100 °C and stir for 8 hours. After cooling the reaction solution to room temperature, add a large amount of deionized water and dichloromethane for extraction, and retain the organic phase. After removing the organic solvent by vacuum distillation, purify by silica gel column chromatography to obtain 101 g of Intermediate 1, with a yield of 87%.

[0211] ② Dissolve intermediate 1 (100 g), 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophene-3-amine (85 g) and anhydrous cesium carbonate (170 g) in diphenyl ether (200 mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and dichloromethane to extract, and retain the organic phase. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 105 g of intermediate 2 with a yield of 62%.

[0212] ③ Dissolve intermediate 2 (100g), 1-[4-(2-methylprop-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine (38g), tri(dibenzylideneacetone)dipalladium (3.5g), tri-tert-butylphosphine tetrafluoroborate (4.5g) and anhydrous sodium tert-butoxide (25g) in toluene (500mL), heat to reflux and stir overnight. After the reaction solution is cooled to room temperature, a large amount of deionized water and dichloromethane are added to extract, and the organic phase is retained. After the organic solvent is removed by reduced pressure distillation, it is purified by silica gel column chromatography to obtain 65g of intermediate 3-4 with a yield of 57%.

[0213] ④ Dissolve the intermediate 3-1 (10g) in tert-butylbenzene (300mL), and add tert-butyl lithium (16mL, 1.3M n-hexane solution) dropwise under an ice bath. After the addition is complete, heat the reaction solution to 100°C and stir for 2 hours. Subsequently, cool the reaction solution to an ice bath and add boron tribromide (5.2mL). After the addition is complete, heat to 180°C and stir for 8 hours. Subsequently, add N,N-diisopropylethylamine (24mL) dropwise under an ice bath. After the addition is complete, heat to 180°C and stir overnight. After the reaction solution is cooled to room temperature, add a large amount of deionized water and extract with dichloromethane, and retain the organic phase. After removing the organic solvent by reduced pressure distillation, purify by silica gel column chromatography to obtain 2.5g of compound 3 with a yield of 24%. Product characterization: 11H NMR (600 MHz, MethyleneChloride-d2) δ 8.68 (d, J = 1.9 Hz, 1H), 8.39 (d, J = 1.9 Hz, 1H), 8.31–8.27 (m, 2H), 7.90 (d, J = 8.4 Hz, 1H), 7.78 (s, 1H), 7.73 (d, J = 8.3 Hz, 1H), 7.67 (dd, J = 8.8, 2.1 Hz, 1H), 7.49 (dt, J = 15.2, 9.6 Hz, 3H), 7.43 (dd, J = 8.4, 1.8 Hz, 1H), 6.79 (s, 1H), 6.65 (d, J = 1.8 Hz, 1H), 6.33 (s, 2H), 6.04 (s, 1H), 4.22 (s, 1H), 3.84 (s, 1H), 3.35 (s, 1H), 3.29 (s, 1H), 3.19 (s, 2H), 3.08 (s, 1H), 2.42 (s, 1H), 1.96 (d, J = 12.8 Hz, 1H), 1.87–1.81 (m, 1H), 1.66 (s, 8H), 1.55 (s, 1H), 1.52 (s, 10H), 1.30 (s, 18H), 1.19 (s, 9H), 1.05 (s, 9H). MS (ASAP) = 1010.6. The mass spectrum is as attached Figure 10 as shown

[0214] Comparative Example 1

[0215] This comparative example provides an organic material, whose chemical structure is as shown in Comparative Compound 1

[0216] The optical properties of the organic materials in the above examples and comparative examples were tested respectively:

[0217] 1. The fluorescence emission spectra of the organic materials provided in each example and comparative example were tested respectively. Among them, the spectral diagrams of the ultraviolet-visible absorption spectra (abs) and fluorescence emission spectra (FL) of the organic materials provided in Examples 1 to 4 in toluene (tol) are as attached Figures 11 to 14 as shown. The test results of the wavelength Peak, full width at half maximum FWHM and photoluminescence quantum yield PLQY of the fluorescence emission peaks of the corresponding organic materials are shown in Table 1 below:

[0218] Table 1

[0219]

[0220] As can be seen from the test data in Table 1, the organic materials constructed by the boron-nitrogen framework unit and the polycyclic aromatic amine substitution unit with a fused-ring structure in the embodiments of the present application are all blue-light materials with high polymer rigidity, having a high photoluminescence quantum yield, a narrowed full width at half maximum, and a light color that better meets the application requirements of high color rendering index blue-light display devices for materials. However, the organic material provided in Comparative Example 1 has a relatively wide full width at half maximum and a low photoluminescence quantum yield. The fluorescence spectra of the organic materials provided in Comparative Example 2 and Comparative Example 3 have a certain degree of red shift, which is not conducive to meeting the application requirements of high color rendering index blue-light display devices. The organic material provided in Comparative Example 4 has a relatively wide full width at half maximum and a low photoluminescence quantum yield.

[0221] 2. Apply the organic materials provided in each embodiment and comparative example to an OLED device, and prepare the OLED device according to the following steps:

[0222] ① Use a transparent glass as the substrate. The glass substrate includes an anode (ITO (15 nm) / Ag (150 nm) / ITO (15 nm)). The surface of the anode is ultrasonically cleaned with a stripping solution (strip solution), pure water, and isopropyl alcohol respectively, then dried and subjected to AR2 ozone treatment.

[0223] ② Transfer the cleaned substrate into a vacuum vapor deposition device. Under a high vacuum (1×10 -6 mbar), control the ratio of compound PD to compound HT-1 to be 3:100 to form a 10-nm hole injection layer (HIL).

[0224] ③ On the hole injection layer, deposit a 10-nm hole transport layer material compound HT-1 by vacuum evaporation.

[0225] ④ On the hole transport layer, deposit a 10-nm electron blocking layer material compound HT-2 by vacuum evaporation.

[0226] ⑤ On the electron blocking layer, deposit a light-emitting layer by vacuum evaporation. The host material is compound BH, and the guest material is one of the organic materials provided in Examples 1 to 4 and Comparative Examples 1 to 4. The mass ratio of the host material to the guest material is 98:2, and the thickness is 25 nm.

[0227] ⑥ On the light-emitting layer, deposit a 2-nm hole blocking layer material compound ET-1 by vacuum evaporation.

[0228] ⑦ On the hole blocking layer, deposit a compound ET-2 and compound LiQ with a mass ratio of 50:50 as the electron transport layer by vacuum evaporation, and the thickness is 35 nm.

[0229] ⑧ On the electron transport layer, deposit 1.5 nm of Yb as the electron injection layer by vacuum evaporation.

[0230] ⑨ A Mg:Ag alloy with a mass ratio of 1:9 and a thickness of 17 nm was evaporated onto the electron injection layer as the cathode; a CPL material was evaporated onto the cathode layer to form a continuous laminated material layer with a thickness of 55 nm, and an OLED device was obtained.

[0231] The performances of the OLED devices prepared by applying the organic materials in Example 1, Example 4 and Comparative Example 1, such as voltage, current efficiency, external quantum efficiency (EQE), peak wavelength of the fluorescence emission spectrum, full width at half maximum (FWHM) of the emission spectrum, etc., were respectively tested, and the test results are shown in Table 2 below:

[0232] Table 2

[0233]

[0234] It can be seen from the test data in Table 1 that, compared with Comparative Example 1, the organic materials provided in Example 1 and Example 4 of the present application effectively narrow the emission FWHM, the light color can be flexibly adjusted, the photoluminescence quantum yield is high, and after being applied to the OLED device, it can better improve the current efficiency and external quantum efficiency of the OLED device and narrow the emission spectrum FWHM of the OLED device.

[0235] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The protection scope of the present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An organic material, characterized in that, It includes the following boron-nitrogen framework unit of formula (I) and substituted structural units of formula (II-1) and / or formula (II-2), and at least one of the substituted structural units forms a substitution bond with at least one ring structure in the boron-nitrogen framework unit; Among them, ring A, ring B, and ring C are each independently selected from one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; X is selected from B, N, P, P=O, or Al; Y and Z are each independently selected from C=O, N-R3, O, S, Se, P, P=O, or P=S; R1, R2, and R3 are each independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; W1, V1, W2, and V2 are each independently selected from C, N, P, Si, or Al.

2. The organic material according to claim 1, characterized in that, The organic material includes at least one of the following formula (III), formula (IV), formula (V), and formula (VI); 3. The organic material according to claim 1 or 2, characterized in that, The X is selected from B.

4. The organic material according to claim 3, characterized in that, At least one of the Y and the Z is selected from N.

5. The organic material according to claim 3, wherein The Y and the Z are selected from the same element.

6. The organic material according to any one of claims 1, 2, 4 or 5, characterized in that, The A ring and the B ring are each independently selected from one of a substituted aryl group, a substituted heteroaryl group, and a substituted fused ring group.

7. The organic material according to claim 6, wherein, The C ring is selected from an aryl group.

8. The organic material according to any one of claims 1, 2, 4, 5 or 7, characterized in that, At least one of the W1 or the V1 is selected from N, or at least one of the W2 or the V2 is selected from N.

9. The organic material according to claim 8, wherein The W1 and the V1 are selected from the same element, or the W2 and the V2 are selected from the same element.

10. The organic material according to any one of claims 1, 2, 4, 5, 7 or 9, characterized in that, The organic material includes At least one of them; wherein, each time D appears, it is independently selected from one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted fused ring structure, a substituted or unsubstituted alkyl group, and hydrogen.

11. A method for preparing an organic material, characterized in that, It includes the following steps: Connect at least one substituted structural unit in the following formula (II-1) and / or formula (II-2) to at least one ring structure in the boron-nitrogen framework unit of formula (I) through a substitution reaction to obtain an organic material; Among them, ring A, ring B, and ring C are each independently selected from one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; X is selected from B, N, P, P═O or Al; Y and Z are each independently selected from C═O, N-R3, O, S, Se, P, P═O or P═S; R1, R2, and R3 are selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted fused ring groups; W1, V1, W2, and V2 are each independently selected from C, N, P, Si or Al.

12. The preparation method of the organic material according to claim 11, characterized in that, The organic material includes Compound 1 Compound 2 Compound 3 Compound 4 and at least one of them.

13. The preparation method of the organic material according to claim 12, wherein, It includes the following steps: Use 2,6-difluoro-4-bromo-chlorobenzene and 3,6-di-tert-butylcarbazole to prepare intermediate 1 through a first substitution reaction; Perform a second substitution reaction on the intermediate 1 with 5-(tert-butyl)-N-(4-(tert-butyl)phenyl)benzo[b]thiophen-3-amine to obtain intermediate 2; Perform a third substitution reaction on the intermediate 2 with 6-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 1-phenyloctahydro-1H-pyrrolo[4,3-b]pyridine, 6-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine, or 1-[4-(2-methylpropan-2-yl)phenyl]octahydro-1H-pyrrolo[4,3-b]pyridine to obtain intermediate 3 respectively, and the intermediate 3 includes intermediate 3-1, intermediate 3-2, intermediate 3-3, or intermediate 3-4; Perform a substitution cyclization reaction on the intermediate 3 respectively to obtain the compound 1, the compound 2, the compound 3, or the compound 4.

14. The method for preparing an organic material according to claim 13, wherein, The temperature condition of the first substitution reaction is 80°C to 120°C, and the reaction duration is 6h to 10h; And / or, the catalyst for the first substitution reaction includes at least one of cesium carbonate anhydrous, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide; And / or, the solvent for the first substitution reaction includes at least one of N,N-dimethylformamide, tetrahydrofuran, 2-methyltetrahydrofuran, acetone, 1,4-dioxane, acetonitrile, diethylene glycol dimethyl ether, toluene, and dichloromethane.

15. The preparation method of the organic material according to claim 13, characterized in that, The second substitution reaction is carried out under stirring conditions heated to reflux for 12h to 24h; and / or, the catalyst for the second substitution reaction comprises at least one of anhydrous cesium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, and sodium hydroxide; And / or, the solvent for the second substitution reaction includes at least one of diphenyl ether and dibenzyl ether.

16. The preparation method of the organic material according to claim 13, characterized in that, The third substitution reaction is reacted for 12 to 24 hours under stirring conditions of heating to reflux; And / or, the catalyst for the third substitution reaction comprises tris(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and anhydrous sodium tert-butoxide; And / or, the solvent for the third substitution reaction includes at least one of toluene, benzene, chlorobenzene, tetrahydrofuran, diethylene glycol dimethyl ether, and dichloromethane.

17. The method for preparing an organic material according to claim 13, characterized in that, The steps of the substitution cyclization reaction include: dissolving the intermediate 3 in an organic solvent, adding a lithium reagent dropwise at a temperature not higher than 10°C, heating to 80°C to 120°C and reacting for 1h to 3h; dropping a boron source dropwise at a temperature not higher than 10°C, heating to 160°C to 200°C and reacting for 6h to 10h; dropping N,N-diisopropylethylamine dropwise at a temperature not higher than 10°C, heating to 160°C to 200°C and reacting for 12h to 24h; and separating to obtain the organic material.

18. The preparation method of the organic material according to claim 17, characterized in that, The organic solvent includes at least one of tert-butylbenzene; And / or, the lithium reagent includes at least one of n-butyl lithium, tert-butyl lithium, and lithium diisopropylamide; And / or, the boron source includes at least one of boron tribromide.

19. An organic electroluminescent device, characterized in that, The invention comprises an anode, a cathode and a light-emitting layer stacked between the anode and the cathode, wherein the light-emitting layer contains the organic material according to any one of claims 1 to 10, or the organic material prepared by the method according to any one of claims 11 to 18.

20. The organic electroluminescent device according to claim 19, characterized in that, In the light-emitting layer, the mass percentage of the organic material is 0.5% to 5%.

21. The organic electroluminescent device according to claim 19 or 20, characterized in that, The light-emitting layer further contains compound BH and at least one organic light-emitting material in 22. The organic electroluminescent device according to claim 19, characterized in that, A hole functional layer is further arranged between the anode and the light-emitting layer of the organic electroluminescent device, and an electron functional layer is further arranged between the light-emitting layer and the cathode.

23. The organic electroluminescent device according to claim 22, characterized in that, Along the direction from the anode to the light-emitting layer, the hole functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer; And / or, along the direction from the cathode to the light-emitting layer, the electronic functional layer includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer.

24. The organic electroluminescent device according to claim 23, wherein, The material of the hole injection layer includes compound PD Compound HT-1 At least one of 3,4-ethylenedioxythiophene and polyaniline; And / or, the material of the hole transport layer includes compound HT-1 At least one of N,N'-diphenanthryl-N,N'-diphenylbenzidine and 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline]; And / or, the material of the electron blocking layer includes compound HT-2 At least one of 4,7-bis(trimethyl)-2-(2-phenyl)-benzotriazole-5-(4-pyrenyl)phenanthrene and 2,9-eicosylbenzo[1,2-b:4,5-b']dithiophene; And / or, the material of the electron injection layer includes at least one of Yb, lithium cobalt fluoride, and triphenylamine; And / or, the material of the electron transport layer includes compound ET-2 Compound LiQ At least one of 2,9-diisobutyldodecyl bis-sulfone and triphenylamine; And / or, the material of the hole blocking layer includes compound ET-1 At least one of 4,4'-bis(N-pyrazinyl)biphenyl and lithium cobalt fluoride.

25. An optoelectronic device, characterized in that, The organic electroluminescent device comprises the organic electroluminescent device as claimed in any one of claims 19 to 24.

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