Boron-containing organic compound and organic electroluminescent device

Abstract

The invention discloses a boron-containing organic compound and an organic electroluminescent device, and relates to the field of luminescent devices. According to the organic compound provided by the invention, a polycyclic structure formed by B, N, Z1 and Z2 and N-Re on the outer side are fused with a ring A to form a compound with a novel structure, and the boron-containing organic compound is used as a fluorescent doping material; and the luminous efficiency and the service life of the prepared green-light super-fluorescent organic electroluminescent device or red-light super-fluorescent organic electroluminescent device can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of light-emitting device technology, and more specifically, to a boron-containing organic compound and an organic electroluminescent device. Background Technology

[0002] With the advent of the 5G era, display technology has placed higher demands on color rendering standards. Luminescent materials not only need to possess high efficiency and stability, but also require improved color purity through narrow half-widths (HWHM). Currently, fluorescent doped materials have achieved high fluorescence quantum yields and narrow HWHMs through molecular engineering; the HWHM of boron-based materials in the blue fluorescence field can be reduced to below 30 nm. However, in the green light region, where the human eye is more sensitive, research still mainly relies on phosphorescent doped materials, whose emission peak shape is difficult to narrow using simple methods. Therefore, developing high-efficiency green fluorescent doped materials with narrow HWHMs has become crucial to meeting high-end color rendering standards.

[0003] To overcome the bottleneck of insufficient exciton utilization in traditional fluorescent materials, TADF-sensitized fluorescence (TSF) technology was developed. This technology combines TADF materials with fluorescent doping materials, using TADF as the exciton sensitization medium to convert electrically excited triplet excitons into singlet excitons, which are then transferred to the fluorescent doping material via long-range energy transfer, enabling the device to achieve a quantum efficiency of up to 100%. This technology fully leverages the advantages of fluorescent materials, such as high quantum yield, high stability, high color purity, and low cost, opening up broad prospects for OLED applications.

[0004] Boron compounds with resonant structures are ideal for TSF (Thin Full Wide Band) luminescence due to their ability to achieve narrow half-peak widths (HWHM). In existing technologies, luminescent layer combinations using TADF materials with a minimum singlet-to-triplet energy level difference ≤0.2 eV as the main body and boron-containing materials as dopants, or schemes using excimer complexes as the main body and boron-containing materials as dopants, have achieved efficiencies comparable to phosphorescence and narrow HWHMs. Therefore, TADF-sensitized fluorescence technology based on narrow HWHM boron-based luminescent materials exhibits unique advantages and strong potential for achieving high color rendering standards such as BT.2020.

[0005] However, there is still a need to develop high-efficiency fluorescent doped materials with narrow half-width to improve luminescence efficiency and lifespan.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a boron-containing organic compound and an organic electroluminescent device, which aims to improve the luminous efficiency and lifespan of the device.

[0008] This invention is implemented as follows: In a first aspect, the present invention provides a boron-containing organic compound having the structure shown in general formula I: ; Wherein, ring A is a benzene ring that is absent, substituted or unsubstituted, or a naphthalene ring that is substituted or unsubstituted; Z1 and Z2 are each independently selected from chemical bonds, BR1, CR2R3, NR4, O, PR5, SiR6R7, GeR8R9, S, CO, or SO2; m and n are each independently selected from 0, 1, 2 or 3; p is selected from 0, 1, or 2; R a To R c R e R f R1-R9 are each independently selected from one of the following: hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted silyl, substituted or unsubstituted boronyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted 3-30 heteroaryl. R of adjacent rings a To R c R e R f R1 to R9 may or may not form a loop.

[0009] Secondly, the present invention also provides an organic electroluminescent device, comprising: an organic layer containing a light-emitting layer, wherein the light-emitting layer contains the boron-containing organic compound described in the above embodiments.

[0010] The present invention has the following beneficial effects: The organic compound provided by the present invention has a polycyclic structure containing B, N, Z1, and Z2, which forms a novel structural compound with the outer N-Re fused ring A. Using it as a fluorescent dopant material in the light-emitting layer of a device is beneficial to significantly improve the luminous efficiency and lifespan of the device.

[0011] First, the strong electron push-pull effect between the outer nitrogen N-Re core (as electron donor, D) and the boron-nitrogen core (as electron acceptor, A) results in the HOMO being distributed on the donor (nitrogen-based five-membered ring), while the LUMO is mainly distributed on the acceptor (boron-nitrogen main nucleus). This high spatial separation between the HOMO and LUMO significantly reduces ΔE. stThis allows triplet excitons to efficiently return to the singlet state and emit light via reverse system-reverse crossover (RISC), effectively improving exciton utilization. Furthermore, this DA structure typically possesses a rigid fused-ring framework, which effectively suppresses non-radiative transitions caused by molecular vibrations and rotations, further enhancing luminescence efficiency. The presence of donor and acceptor units enables the molecule to simultaneously possess the ability to transport holes (contributed by the donor) and electrons (contributed by the acceptor). This bipolar characteristic facilitates a balance between hole and electron injection and transport in OLED devices, thereby improving device efficiency.

[0012] Secondly, the fused rings A and Z1, Z2 above the five-membered ring on the right side of the compound core of this invention significantly expand the conjugated system, resulting in better charge transport capability and effectively improving the luminous efficiency of the device. At the same time, it enhances molecular rigidity, improves planarity, and enhances optical and thermal stability, which helps to improve the lifespan of the device. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 The image shows the 1H NMR spectrum of compound 78. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0016] The term "substituted or unsubstituted" in this invention means that the group may not be substituted, or may be substituted by one or more substituents. "Substitution" means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent, and there is no restriction on the position of substitution, as long as the position is where the hydrogen atom is substituted, that is, the position where the substituent can be substituted. When two or more substituents are substituted, the two or more substituents may be the same as or different from each other.

[0017] This invention provides a boron-containing organic compound having the structure shown in general formula I: ; In Formula I, ring A is a benzene ring that is absent, substituted, or unsubstituted, or a naphthalene ring that is substituted or unsubstituted. That is, ring A may be absent. When ring A is present, ring A is a benzene ring or a naphthalene ring. Substituents may or may not be present on the benzene ring or the naphthalene ring.

[0018] In Formula I, Z1 and Z2 are each independently selected from chemical bonds, BR1, CR2R3, NR4, O, PR5, SiR6R7, GeR8R9, S, CO, or SO2. Z1 and Z2 can be the same or different, and can be independently selected from any of the above.

[0019] In Equation I, m and n are each independently selected from 0, 1, 2, or 3; m and n can be the same or different. p is selected from 0, 1, or 2. The R of adjacent rings... a To R c R e R f R1 to R9 may or may not form a loop, meaning that adjacent R1 to R9 are connected to each other. a To R c R e R f R1 to R9 can form a ring or be substituted.

[0020] R a To R c R e R f R1-R9 are each independently selected from hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted silyl, substituted or unsubstituted boryl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C6-C60 arylamine, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted 3-30 heteroaryl. Taking C1-C10 as an example, it refers to the number of carbon atoms 1-10, such as C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.

[0021] In some embodiments, based on different Z2, general formula I is selected from formula I-1 to formula I-10:

[0022] .

[0023] Preferably, R a To R c R e R fR1 to R9 are each independently selected from one of the following: hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted silyl, substituted or unsubstituted boronyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C6-C24 aryloxy, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C6-C24 aryl, or substituted or unsubstituted 3-24 heteroaryl.

[0024] Furthermore, based on the different Z1, general formula I is selected from formula I-11 to formula I-21:

[0025] ; q and r can be the same or different, and each can be independently selected from 0, 1 or 2.

[0026] In a preferred embodiment, R a To R c R e R f R1-R9, R 10 -R 11 Each group is independently selected from hydrogen, deuterium, cyano, and the following groups:

[0027] .

[0028] It should be noted that by optimizing each substituent, the luminous efficiency and lifetime of the device can be further improved.

[0029] In a further preferred embodiment, R1-R9, R 10 -R 11 They can be the same or different, R1-R9, R 10 -R 11 Each group is independently selected from: hydrogen, deuterium, methyl, phenyl, naphthyl, F, CF3, CD3, methylphenyl, and the following groups: R1-R9, R 10 -R 11 It can be any of the above.

[0030] In a further preferred embodiment, R a To R c They can be the same or different, R a To R c Each is independently selected from: hydrogen, deuterium, methyl, phenyl, naphthyl, F, CF3, CD3, trimethylsilyl, trimethylgermanyl, cyano, methylphenyl, trimethylphenyl. Ra R b R c It can be any of the above.

[0031] R e R f They can be the same or different, R e R f Each and every one of them is selected independently from:

[0032]

[0033]

[0034]

[0035]

[0036] Heteroaryl groups include monocyclic aromatic groups and polycyclic aromatic ring systems with at least one heteroatom, where the heteroatom is O, S, or N.

[0037] "Substituted or unsubstituted" means substituted with one, two or more of the following substituents: deuterium; halogen group; nitrile group; C1-C10 alkyl; C3-C10 cycloalkyl; alkoxy; C6-C24 aryl; C3-C24 heterocyclic group, or substituted with two or more of the substituents shown above linked together, or without substituents.

[0038] "Substitution with deuterium" means that at least one hydrogen atom in the group is recoordinated with deuterium.

[0039] Formula I is selected from compounds 1 to 357:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] .

[0057] It should be noted that compounds 1 to 357 exhibit excellent performance when used as fluorescent dopant materials in the luminescent layer, significantly improving the luminous efficiency and lifespan of organic electroluminescent devices.

[0058] This invention also provides a method for preparing the above-mentioned boron-containing organic compound. The synthesis method can be carried out with reference to one or more of the following steps, including: Intermediate c-78 was synthesized by reacting reactant a-1 and reactant b-1. Intermediate e-1 was synthesized by reacting intermediate c-78 with reactant d-1. Intermediate g-1 was synthesized by reacting intermediate e-1 with reactant f-1. Intermediate i-1 was synthesized by reacting intermediate g-1 with reactant h-1. Intermediate formula I is synthesized using intermediate i-1; The synthetic route is as follows (but is not limited to the following synthetic route; any scheme that can achieve the above reaction process is within the protection scope of this invention):

[0059] In Equation I, rings A, Z1, Z2, m, n, p, and R are defined. a -R c R f R e The definition is the same as above; Hal1, Hal2, Hal3 are selected from Cl, Br, I; q is selected from 0 or 1.

[0060] This invention also provides an organic electroluminescent device, comprising: an organic layer containing a light-emitting layer, wherein the light-emitting layer contains a boron-containing organic compound provided in this invention.

[0061] Organic light-emitting devices can have structures comprising organic layers such as a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a capping layer. However, the structure of organic light-emitting elements is not limited to this and can contain fewer or more organic layers.

[0062] Regarding the compound shown in Formula I above, the organic layer can be formed using either vacuum evaporation or solution coating when manufacturing organic light-emitting elements. Solution coating methods include spin coating, dip coating, blade coating, inkjet printing, screen printing, spray coating, and roll coating, but are not limited to these.

[0063] Depending on the material used, the organic light-emitting element of the present invention can be a top-emitting type, a bottom-emitting type, or a bidirectional-emitting type.

[0064] The device described in this invention can be used in organic light-emitting devices, organic solar cells, electronic paper, organic photoreceptors, or organic thin-film transistors.

[0065] As an anode material, a material with a high work function is preferred in order to facilitate the injection of holes into the organic layer. Specific examples of anode materials that can be used in this invention include metals such as vanadium, chromium, copper, zinc, and gold, or their alloys; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); and combinations of metals and oxides such as ZnO:Al or SnO2:Sb.

[0066] The hole injection layer is preferably a p-doped hole injection layer, which means a hole injection layer doped with a p-doped agent. A p-doped agent is a material that can impart p-type semiconductor characteristics. P-type semiconductor characteristics refer to the characteristics of injecting or transporting holes at the HOMO energy level, that is, the characteristics of a material with high hole conductivity.

[0067] Hole transport materials are materials capable of receiving holes from the anode or hole injection layer and transporting them to the light-emitting layer; they are materials with high hole mobility. Hole transport materials can be selected from aryl amine derivatives, conductive polymers, and block copolymers containing both conjugated and non-conjugated parts.

[0068] An auxiliary light-emitting layer (multilayer hole transport layer) is added between the hole transport layer and the light-emitting layer. The auxiliary light-emitting layer primarily assists the hole transport layer and is therefore sometimes referred to as a second hole transport layer. This layer allows holes transferred from the anode to smoothly move to the light-emitting layer and blocks electrons transferred from the cathode, confining them within the light-emitting layer. This reduces the potential barrier between the hole transport layer and the light-emitting layer, lowers the driving voltage of the organic light-emitting device, and further increases hole utilization, thereby improving the device's luminous efficiency and lifetime.

[0069] The luminescent layer comprises a host material and a dopant material. The dopant material includes phosphorescent dopant and fluorescent dopant, with the fluorescent dopant being a boron-containing organic compound provided in this embodiment of the invention. The mass ratio of the host material to the dopant material is (90-99.5):(0.5-10), such as 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, 98:2, 99:1, 99.5:0.5, etc.

[0070] The main materials include aromatic fused-ring derivatives or heterocyclic compounds. Specifically, aromatic fused-ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentanebenzene derivatives, phenanthrene compounds, and fluoranthene compounds; heterocyclic compounds include carbazole derivatives, dibenzofuran derivatives, and pyrimidine derivatives. The dopant material can be selected from aromatic amine derivatives, styrylamine compounds, boron complexes, fluoranthene compounds, metal complexes, etc., and includes the fluorescent dopant material of Formula I of this invention.

[0071] An electron transport layer can facilitate electron transport. The electron transport material is one that advantageously receives electrons from the cathode and transports them to the light-emitting layer, preferably a material with high electron mobility. The electron transport layer may include at least one of an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and preferably at least one of an electron transport layer and an electron injection layer.

[0072] The electron injection layer can promote electron injection and prevent excitons generated in the light-emitting layer from migrating to the hole injection layer. Materials for the electron injection layer include, but are not limited to, oxazoles, oxadiazoles, triazoles, imidazoles, perylenetetracarboxylic acids, fluorenemethane, anthrones and their derivatives, metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, ytterbium, or their alloys, metal complexes, or nitrogen-containing 5-membered ring derivatives.

[0073] The cathode is typically made of a material with a low work function to facilitate electron injection into the organic material layer, the thickness of which is preferably between 0.5 and 5 nm. The cathode material is generally preferred to have a low work function in order to facilitate electron injection into the organic layer. Specific examples of cathode materials include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or their alloys; among which, alloys are selected from multilayer structures such as LiF / Al or LiO2 / Al, Mg / Ag, etc.

[0074] Apart from the doped materials containing Formula I disclosed herein, there are no special restrictions on other layer materials in OLED devices.

[0075] The following detailed description, in conjunction with specific embodiments, illustrates a boron-containing organic compound and an organic electroluminescent device provided by the present invention.

[0076] Example 1 - Synthesis of Compound 78 The synthetic route for compound 78 is as follows:

[0077] The specific synthesis steps are as follows: (1) Dissolve reactant a-78 (1.0 eq) in diethyl ether, add Ti(OiPr)4 (1.3 eq) and 2 c-C5H9MgCl (1.3 eq), cool the mixture to -30 °C under N2 protection, stir for 1.5 h, add reactant b-78 (1.5 eq), react at -30 °C for 3 h, quench with 1 N HCl solution and stir for 0.5 h, after the reaction is completed, neutralize with saturated sodium bicarbonate solution, extract, combine organic phases, and the crude product is subjected to silica gel column chromatography to obtain intermediate c-78 (71.5%).

[0078] (2) Intermediate c-78 (1.0 eq), reactant d-78 (1.3 eq), potassium fluoride (KF) (1.0 eq), and 18-crown-6 (1.0 eq) were dissolved in acetonitrile (CH3CN) (1.3 eq). The mixture was stirred at room temperature for 13 hours under N2 protection. Then, 1 N HCl was added to the reaction mixture, and the mixture was stirred at room temperature for 3.0 hours. The mixture was then neutralized with saturated sodium bicarbonate solution, extracted, and the organic phases were combined. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate, 150:1 to 100:1) to give intermediate e-78 (73.4%).

[0079] (3) Under N2 protection, reactant f-78 (1.0 eq) and cesium carbonate (Cs2CO3) (1.0 eq) were dissolved in N2 solution. methyl 2 Pyrrolidone (NMP) was added to intermediate e-78 (1.0 eq). After heating at 100 °C for 16 hours, the reaction mixture was cooled to room temperature and diluted with ethyl acetate and water. The organic phases were combined, and the oily residue was diluted with dichloromethane (5 mL) and methanol (50 mL) was added. The suspension was then stirred overnight at room temperature and filtered to give intermediate g-78 (85.7%).

[0080] (4) Under N2 protection, a pentane solution of tert-butyllithium (4.5 eq) was slowly added to a tert-butylbenzene solution of intermediate g-78 (1.0 eq), and then the temperature was raised to 60℃, 80℃, and 100℃ for 3 hours each. After the reaction was completed, the temperature was lowered to -40℃, and boron tribromide (5.0 eq) was slowly added. The mixture was stirred at room temperature for 0.5 hours. N,N-diisopropylethylamine (EtN(I-Pr)2, 5.0 eq) was added at room temperature, and the reaction was continued at 140℃ for 6 hours before stopping. After cooling to room temperature, a tetrahydrofuran solution of reactant h-78 (8.0 eq) was slowly added, and the mixture was stirred for 12 hours. The solvent was evaporated under vacuum, and the mixture was subjected to silica gel column chromatography (petroleum ether: dichloromethane = 15:1) to obtain compound 78 (22.6%, MS (ESI, m / Z): [M+H]+ = 696.52).

[0081] Characterization: The proton NMR spectrum of compound 78 is as follows: Figure 1 As shown.

[0082] HPLC purity: >99.7%.

[0083] Elemental analysis: Theoretical values: C, 87.95; H, 4.92; B, 3.10; N, 4.02; Test values: C, 87.71; H, 5.15; B, 3.09; N, 4.08.

[0084] In addition, it should be noted that other compounds in this application can be obtained by referring to the preparation methods of the examples listed above, so they will not be listed one by one here.

[0085] I. Simulation Calculation In this invention, for specific structures represented by representative structural formulas, density functional theory (DFT) and time-varying density functional theory (TD-DFT) calculations were performed using the Gaussian16 program, a standard procedure in this technical field. The calculation parameters were set as follows: B3LYP functionals were used, and a mixed basis set system was selected (LANL2DZ pseudopotential basis set for metal atoms, and 6-31G(dp) basis set for non-metal atoms). Through the above calculations, the physical properties of this specific structure as a TADF luminescent material (including but not limited to emission wavelength, fluorescence quantum yield, excited-state lifetime, HOMO / LUMO energy levels, etc.) were predicted and verified. Based on these functional theory calculations, compound 1 (Application Example 1) and compound 78 (Application Example 21) with green luminescence properties were designed, and compound 259 (Application Example 61) and compound 260 (Application Example 62) with red luminescence properties were designed and verified. See Table 1 for details.

[0086] Table 1: Simulation Results

[0087] II. Fabrication of Organic Electroluminescent Devices Application Example 1 - Fabrication of a green superfluorescent organic electroluminescent device: A method for fabricating a green organic electroluminescent device includes the following steps: a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150nm is cleaned twice in distilled water, ultrasonically washed for 30 minutes, then repeatedly cleaned twice in distilled water, ultrasonically washed for 10 minutes, and baked in a vacuum oven at 220℃ for 2 hours. After baking, it can be used after cooling. Using this substrate as the anode, the device process is carried out by vapor deposition machine, and other functional layers are sequentially vapor deposited on it. b. HIL (Hole Injection Layer): Hole injection layer materials HT and P-dopant are vacuum-deposited at a deposition rate of 1 Å / s, and their chemical formulas are shown below; the deposition rate ratio of HT and P-dopant is 97:3, and the thickness is 10 nm. c. HTL (Hole Transport Layer): A 130 nm HT layer is vacuum-deposited on the hole injection layer at a deposition rate of 1.0 Å / s as a hole transport layer. d. Prime (light-emitting auxiliary layer): A 40 nm prime layer is vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a light-emitting auxiliary layer; e. EML (Light Emitting Layer): On the light-emitting auxiliary layer, a host material (GH-1+GH-2) and a dopant with a total thickness of 30 nm are vacuum-deposited at a deposition rate of 1 Å / s, and Formula I of the present invention are used as doping materials for the light-emitting layer. GH-1 and GH-2 are used as dual host materials and are co-deposited with the dopant and Formula I. The ratio of GH-1 to GH-2 is 50%:50%, and the deposition rate ratio of host material, dopant and Formula I is 89:10:1. f. HBL (hole blocking layer): A hole blocking layer HB with a thickness of 5.0 nm is vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s. g. ETL (Electron Transport Layer): ET and Liq with a thickness of 30 nm are vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s as an electron transport layer; the deposition rate ratio of ET to Liq is 50:50. h. EIL (Electron Injection Layer): A 1.0 nm Yb film is deposited on the electron transport layer at a deposition rate of 0.5 Å / s to form the electron injection layer; i. Cathode: Magnesium and silver are deposited at a deposition rate of 1 Å / s for 13 nm, with a deposition rate ratio of 1:9, to form the cathode; j. Optical extraction layer: A CPL with a thickness of 60 nm is vacuum-deposited on the cathode at a deposition rate of 1 Å / s as the optical extraction layer. k. Encapsulate the vapor-deposited substrate; First, use a coating equipment to coat the cleaned cover plate with UV adhesive. Then, move the coated cover plate to the lamination section, place the vapor-deposited substrate on the top of the cover plate, and finally, laminate the substrate and cover plate together under the action of the lamination equipment, while simultaneously curing the UV adhesive by light.

[0088] The material structures involved in device fabrication are as follows: .

[0089] Application Example 1-58 Organic electroluminescent devices used in Examples 1-58 were prepared according to the above-described method for preparing organic electroluminescent devices, except that the compounds in Formula I were replaced with the corresponding compounds in Table 2.

[0090] Comparative Application Examples 1-10 Organic electroluminescent devices are prepared according to the above-described method, except that the compounds in Formula I are replaced with comparative compounds 1-10.

[0091] The structures of the substances involved in comparative compounds 1-10 are as follows:

[0092] Under a 15000 (nit) luminance test condition, the driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained from test cases 1-58 and comparative application examples 1-10 were characterized, and the test results are shown in Table 2.

[0093] Table 2 Performance test results of application examples and comparative application examples

[0094] As can be seen from Table 2 above, the compounds shown in Formula I exhibit higher luminous efficiency and longer lifetime in Application Examples 1 to 58 compared to the comparative examples.

[0095] Generally speaking, a 10% improvement in device lifetime is considered a significant performance improvement in the field, with an efficiency increase of more than 5%, which is considered a significant improvement in efficiency.

[0096] At a brightness of 15000 nits, the luminous efficiency of the compound of the present invention is 200.3-210.5 cd / A, while the luminous efficiency of the comparative compound is 175.1-180.9 cd / A, representing an efficiency improvement of 10%-20%. The lifetime of the compound of the present invention is 1040-1120 h, while the lifetime of the comparative compound is 893-938 h, representing a lifetime improvement of 10-25%. It is evident that the compound of the present invention has achieved significant progress in luminous efficiency compared to the prior art.

[0097] Application Example 59: Fabrication of a Red-Light Superfluorescent Organic Electroluminescent Device: a. ITO anode: An ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 14nm / 150nm / 14nm is washed twice in distilled water, ultrasonically cleaned for 30 minutes, then washed twice more in distilled water, ultrasonically cleaned for 10 minutes. After washing, it is transferred to a spin dryer for spin drying, and finally baked in a vacuum oven at 220℃ for 2 hours. After baking, it is cooled down before use. Using this substrate as the anode, the device process is carried out using a vapor deposition machine, and other functional layers are sequentially vapor deposited on it.

[0098] b. HIL (hole injection layer): Hole injection layer materials HT-1 and P-dopant-1 are vacuum-deposited at a deposition rate of 1 / s, and their chemical formulas are shown below; and the deposition rate ratio of HT-1 and P-dopant-1 is 95:5, with a thickness of 10nm. c. HTL (Hole Transport Layer): HT-1 of 130 nm is vacuum-deposited on the hole injection layer at a deposition rate of 1.5 / s as the hole transport layer. d. Prime (light-emitting auxiliary layer): Prime-1 with a wavelength of 90 nm was vacuum-deposited on the hole transport layer at a deposition rate of 0.5 / s as the light-emitting auxiliary layer material; e. EML (Light Emitting Layer): On the light-emitting auxiliary layer, a host material (Host-1) and a dopant material (Dopant-1) with a thickness of 40 nm are vacuum-deposited at a deposition rate of 1 / s, and co-deposited using Formula I. The chemical formulas of Host-1, Dopant-1, and Formula I are shown below, and the deposition rate ratio of Host-1 to Dopant-1 and Formula I is 94:5:1.

[0099] f. HB (hole blocking layer): HB-1 with a thickness of 5.0 nm is vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 / s as a hole blocking layer.

[0100] g. ETL (Electron Transport Layer): ET-1 and Liq with a thickness of 30 nm are vacuum-deposited on the hole blocking layer at a deposition rate of 1 / s as an electron transport layer; the chemical formulas of ET-1 and Liq are shown below, and the deposition rate ratio of ET-1 to Liq is 50:50.

[0101] h. EIL (Electron Injection Layer): A 1.0 nm Yb film is vacuum-deposited on the electron transport layer at a deposition rate of 0.5 / s to form the electron injection layer.

[0102] i. Cathode: Magnesium and silver are vacuum-deposited at a deposition rate of 1 / s on the electron injection layer for 13nm, with a deposition rate ratio of 1:9, to obtain the OLED device.

[0103] j. Optical extraction layer: CPL-1 with a thickness of 70 nm is vacuum-deposited on the cathode at a deposition rate of 1 / s as the optical extraction layer, wherein the chemical formula of CPL is shown below.

[0104] k. Encapsulate the vapor-deposited substrate: First, use a coating equipment to coat the cleaned cover plate with UV adhesive. Then, move the coated cover plate to the lamination section, place the vapor-deposited substrate on the top of the cover plate, and finally, laminate the substrate and cover plate together under the action of the lamination equipment, while simultaneously curing the UV adhesive by light.

[0105] The materials required for each layer are as follows:

[0106]

[0107] Application Examples 59-67 Organic electroluminescent devices of application examples 59-67 were prepared according to the above-described method for preparing organic electroluminescent devices, except that the compounds in Formula I were replaced with the corresponding compounds in Table 3.

[0108] Comparative Application Example 1-Comparative Application Example 15 Organic electroluminescent devices were prepared according to the above-described method, except that the compounds in Formula I were replaced with comparative compounds 11-15.

[0109] The structures of the substances involved in comparative compounds 11-15 are shown below:

[0110] Under a luminance test condition of 6000 nits, the driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained from test cases 59-67 and comparative application examples 11-15 were characterized, and the test results are shown in Table 3.

[0111] Table 3 Performance test results of application examples 59-67 and comparative application examples 11-15

[0112] As can be seen from Table 3 above, the compounds shown in Formula I, in application examples 59 to 67, exhibit higher luminescence efficiency and longer lifetime than the comparative examples.

[0113] At a brightness of 6000 nits, the compound of this invention, as a red-light superfluorescent material, exhibits an efficiency of 60-62 cd / A, compared to 45.8-52.4 cd / A for the comparative compound. The lifetime of the compound of this invention is 1572-1610 h, compared to 1360-1420 h for the comparative compound. Therefore, the compound of this invention represents a significant improvement in luminescent efficiency compared to existing technologies.

[0114] The results of red and green light device analysis show that the organic compound provided by this invention has a polycyclic structure containing B, N, Z1, and Z2, which forms a novel structural compound with the outer N-Re fused ring A. Using this compound as a fluorescent dopant material in the light-emitting layer of the device can significantly improve the luminous efficiency and lifespan of the device.

[0115] The strong electron push-pull effect between the outer nitrogen N-Re core (as electron donor (D) and the boron-nitrogen core (as electron acceptor (A)) results in HOMO distribution on the donor (N-Re), while LUMO is mainly distributed on the acceptor (boron-nitrogen host core). The presence of both donor and acceptor units allows the molecule to simultaneously possess the ability to transport holes (contributed by the donor) and electrons (contributed by the acceptor). This bipolar characteristic is beneficial for balancing hole and electron injection and transport in OLED devices, thereby improving device efficiency.

[0116] In addition, the fused rings A and Z1, Z2 above the five-membered ring on the right side of the compound core of the present invention significantly expand the conjugated system, thereby increasing molecular rigidity, improving planarity, and enhancing optical and thermal stability, which helps to improve the lifespan of the device.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A boron-containing organic compound, characterized in that, Boron-containing organic compounds have the structure shown in general formula I: ； Wherein, ring A is a benzene ring that is absent, substituted or unsubstituted, or a naphthalene ring that is substituted or unsubstituted; Z1 and Z2 are each independently selected from chemical bonds, BR1, CR2R3, NR4, O, PR5, SiR6R7, GeR8R9, S, CO, or SO2; m and n are each independently selected from 0, 1, 2 or 3; p is selected from 0, 1, or 2; R a To R c R e R f R1-R9 are each independently selected from one of the following: hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted silyl, substituted or unsubstituted boronyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted 3-30 heteroaryl. R of adjacent rings a To R c R e R f R1 to R9 may or may not form a loop.

2. The boron-containing organic compound according to claim 1, characterized in that, General formula I is selected from formula I-1 to formula I-10: 。 3. The boron-containing organic compound according to claim 2, characterized in that, R a To R c R e R f R1 to R9 are each independently selected from one of the following: hydrogen, deuterium, fluorine, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted silyl, substituted or unsubstituted boronyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C6-C24 aryloxy, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C6-C24 aryl, or substituted or unsubstituted 3-24 heteroaryl.

4. The boron-containing organic compound according to claim 1, characterized in that, General formula I is selected from formula I-11 to formula I-21: ； q and r are each independently selected from 0, 1, or 2.

5. The boron-containing organic compound according to claim 4, characterized in that, R a To R c R e R f R1-R9, R 10 -R 11 Each group is independently selected from hydrogen, deuterium, cyano, and the following groups: 。 6. The boron-containing organic compound according to claim 5, characterized in that, R1-R9, R 10 -R 11 Each group is independently selected from: hydrogen, deuterium, methyl, phenyl, naphthyl, F, CF3, CD3, methylphenyl, and the following groups: ； And / or, R a To R c Each is independently selected from: hydrogen, deuterium, methyl, phenyl, naphthyl, F, CF3, CD3, trimethylsilyl, trimethylgermanyl, cyano, methylphenyl, trimethylphenyl; And / or, R e R f Each and every one of them is selected independently from: Indicates the connection site.

7. The boron-containing organic compound according to any one of claims 1-6, characterized in that, Formula I is selected from compounds 1 to 357: 。 8. An organic electroluminescent device, characterized in that, include: An organic layer containing a light-emitting layer, wherein the light-emitting layer contains a boron-containing organic compound as described in any one of claims 1-7.

9. The organic electroluminescent device according to claim 8, characterized in that, The light-emitting layer comprises a host material and a dopant material, wherein the dopant material comprises a phosphorescent dopant material and a fluorescent dopant material, and the fluorescent dopant material comprises the boron-containing organic compound.

10. The organic electroluminescent device according to claim 9, characterized in that, The mass ratio of the host material to the doped material is (90-99.5):(0.5-10). And / or, the host material is selected from aromatic fused-ring derivatives or heterocyclic compounds; And / or, the organic layer includes a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer arranged sequentially.

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