Boron-nitrogen-containing organic compound and organic electroluminescent device containing same

Abstract

The invention relates to the technical field of semiconductors, and provides a boron-nitrogen-containing organic compound and an organic electroluminescent device containing the same. The compound serving as a doping material has high fluorescence quantum efficiency, the rigidity of a mother nucleus structure is enhanced after a five-membered heterocycle is fused at a central benzene ring, vibration coupling is effectively inhibited, FWHM is narrowed, and the luminous efficiency of a device is improved; in addition, the rigidity of the material is enhanced, so that the evaporation decomposition temperature is increased, evaporation decomposition of the material is inhibited, and the service life of the device is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a boron-nitrogen-containing organic compound and an organic electroluminescent device comprising the same. BACKGROUND

[0002] The conventional fluorescent dopant material is limited by the early technology, and can only utilize 25% singlet excitons formed by electric excitation to emit light, so that the internal quantum efficiency of the device is low (the highest is 25%), and the external quantum efficiency is generally lower than 5%, which is far from the efficiency of phosphorescent devices. The phosphorescent material can effectively utilize singlet excitons and triplet excitons formed by electric excitation to emit light due to the strong spin-orbital coupling of the heavy atom center, so that the internal quantum efficiency of the device reaches 100%. However, the application of the phosphorescent material in OLEDs is limited by the problems such as high price, poor material stability, poor color purity, and serious device efficiency roll-off.

[0003] With the coming of the 5G era, higher requirements are put forward for the color rendering standard. In addition to high efficiency and stability, the light-emitting material also needs a narrower half-peak width to improve the color purity of the device. The fluorescent dopant material can realize high fluorescent quantum and narrow half-peak width through molecular engineering, and the half-peak width of boron-based material can be reduced to below 30 nm. In addition, the sensitization technology combines triplet exciton sensitization material with fluorescent dopant material, uses triplet exciton sensitization material as exciton sensitization medium, fully utilizes triplet exciton, and transfers energy to fluorescent dopant material through energy transfer, so that the internal quantum efficiency of the device reaches 100%. This technology can make up for the shortcomings of insufficient exciton utilization rate of fluorescent dopant material, effectively play the characteristics of high fluorescent quantum yield, high device stability, high color purity and low price of fluorescent dopant material, and has broad prospects in the application of OLEDs.

[0004] The boron-based compound with resonance structure is easier to realize narrow half-peak width emission. The application of this kind of material in TADF sensitized fluorescent technology can realize the preparation of high-efficiency and narrow half-peak width emission device. Therefore, the development of TADF sensitized fluorescent technology based on narrow half-peak width boron-based light-emitting material has unique advantages and strong potential in the face of BT.2020 display indicators. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a boron-nitrogen-containing organic compound and an organic electroluminescent device comprising the same. The compound of the present application can be used as a light-emitting layer dopant material of an organic electroluminescent device.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] The first technical purpose of the present application is to provide a boron-nitrogen-containing organic compound, the structure of which is shown in general formula (1): ;

[0008] R1-R5are the same or different from each other and are each independently selected from the group consisting of hydrogen, deuterium, cyano, substituted or unsubstituted C1-C20alkyl, substituted or unsubstituted C3-C30cycloalkyl, substituted or unsubstituted C1-C20alkoxy, substituted or unsubstituted C1-C60silyl, substituted or unsubstituted C6-C60aryl, substituted or unsubstituted C2-C60heterocyclyl, the heteroatom in the heterocyclyl being selected from O, N or S;

[0009] n1, n2, n5 are each independently an integer from 0 to 3;

[0010] n3 is independently an integer from 0 to 4;

[0011] n4 is independently an integer from 0 to 14;

[0012] Any two adjacent groups of R1-R5may be bonded to each other to form a ring;

[0013] X is independently selected from one of a bond, O, S, Se, NR6, C(R7)(R8), Si(R7)(R8), Ge(R7)(R8);

[0014] R6, R7and R8are the same or different from each other and are each independently selected from the group consisting of hydrogen, deuterium, methyl, cyano, substituted or unsubstituted C1-C10alkyl, substituted or unsubstituted C3-C10cycloalkyl, substituted or unsubstituted C6-C30aryl, substituted or unsubstituted C7-C30aralkyl, substituted or unsubstituted C6-C30aryloxy, substituted or unsubstituted C3-C30heteroaryl, substituted or unsubstituted C4-C30heteroaralkyl, substituted or unsubstituted C3-C30heteroaryloxy, wherein the heteroatom is one or more of N, O, S, preferably phenyl, wherein R7and R8may be linked to form a ring;

[0015] Ring A represents a fused ring to the adjacent phenyl ring and is independently selected from the group consisting of: ;

[0016] represents a fused position to the adjacent group;

[0017] R9-R 10 are each independently selected from the group consisting of substituted or unsubstituted C1-C6alkyl, substituted or unsubstituted C6-C30aryl, substituted or unsubstituted C6-C30heteroaryl, the heteroatom in the heteroaryl being selected from O, N or S, preferably phenyl, and can be linked to form a ring.

[0018] Further, the compounds of general formula (1) have the structures shown in I-1 to I-18: .

[0019] According to one embodiment of the present application, R1-R5 are each independently selected from the following groups, which can be connected at any substitutable position, and the following groups can be further substituted by deuterium: .

[0020] Further, the "substitution" means substituted by a substituent selected from the group consisting of deuterium, cyano, methyl, C2-C8 alkyl, C6-C24 aryl, C6-C24 heteroaryl, a monocyclic aromatic group or a polycyclic aromatic system having at least one heteroatom, the heteroatom being one or more of O, S, N; the hydrogen atoms in the general formula (1) can be unsubstituted by deuterium, substituted by deuterium in whole or in part.

[0021] According to one embodiment of the present application, the compound having the structure of general formula (1) is selected from any one of L001~L888: .

[0022] The present application also provides an organic electroluminescent device, wherein a light-emitting layer of the organic electroluminescent device comprises a first host material, a second host material and a dopant material, at least one of the first host material and the second host material is a TADF material, and the dopant material is the boron-nitrogen-containing organic compound according to the present application.

[0023] In an embodiment of the present application, the light-emitting layer comprises a host material, an exciton sensitization material and a dopant material, the exciton sensitization material is a metal element-containing complex, and the dopant material is the boron-nitrogen-containing organic compound according to the present application.

[0024] In an embodiment of the present application, the organic electroluminescent device comprises, in sequence, a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a second electrode.

[0025] In an embodiment of the present application, the preparation method of the light-emitting layer comprises, but is not limited to, forming the organic electroluminescent material into a light-emitting layer by a solution coating method and a vacuum deposition method; here, the solution coating method means spin coating, dip coating, inkjet printing, screen printing, spraying and the like, but is not limited thereto.

[0026] In one embodiment of the present application, the first electrode is an anode. As an anode material, a material having a large work function is generally preferred in order to enable holes to be smoothly injected into the organic layer. As the anode material usable in the present application, there are included metals such as vanadium, chromium, copper, zinc, and the like, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), or indium zinc oxide (IZO); combinations of metals and oxides such as ZnO / Al or SnO2 / Sb; conductive polymers such as poly(3-methylthiophene), polypyrrole, or polyaniline; but are not limited thereto. In some embodiments of the present application, the anode is an ITO anode.

[0027] In one embodiment of the present application, the material of the hole injection layer is selected from one or more of metalloporphyrin, oligothiophene, arylamine-based organic material, benzonitrile-based organic material, quinacridone-based organic material, polyaniline-based and polythiophene-based conductive polymer. The material of the hole injection layer is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the material of the hole injection layer is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0028] In one embodiment of the present application, the material of the hole transport layer is selected from one or more of arylamine-based organic material, conductive polymer, block copolymer having both conjugated and non-conjugated portions. The material of the hole transport layer is capable of receiving holes from the anode or the hole injection layer and transporting the holes to the light-emitting layer, having a high hole mobility.

[0029] In one embodiment of the present application, the electron transport layer is selected from one or more of an Al complex of 8-hydroxyquinoline, organic radical compound, but is not limited thereto.

[0030] In one embodiment of the present application, the thickness of the electron transport layer is 1 nm to 50 nm. For example, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm. The electron transport layer can prevent a decrease in electron transport properties, prevent an increase in driving voltage due to the electron transport layer being too thick, and function to facilitate electron transport. The material of the electron transport layer is used to receive electrons from the cathode and transport the electrons to the light-emitting layer, having a high electron mobility.

[0031] In one embodiment of the present application, the electron injection layer is selected from one or more of fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, imidazole, perylene tetracarboxylic acid, fluorenylidene methane, anthrone or a derivative thereof, a metal complex, a nitrogen-containing five-membered ring derivative, but is not limited thereto. The electron injection layer can function to facilitate electron injection, and the electron injection material preferably has the ability to transport electrons, has an effect of injecting electrons from a cathode, has an excellent electron injection effect on a light-emitting layer or a light-emitting material, prevents excitons generated in the light-emitting layer from migrating to a hole injection layer, and in addition thereto, has an excellent thin film formation ability.

[0032] In one embodiment of the present application, the second electrode is a cathode. As a cathode material, a material having a small work function is preferred in order to easily inject electrons to an organic layer. As a specific example of the cathode material, there are included metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or alloys thereof; a multi-layered structure material such as LiF / Al or LiO2 / Al; but is not limited thereto. In some embodiments of the present application, the cathode material is Al.

[0033] In one embodiment of the present application, the organic electroluminescent device can be a top emission type, a bottom emission type, or a dual side emission type.

[0034] The numerical ranges recited herein include all values from and including the lower and upper values. This is true even if the values included in the lower or upper range are outside of the recited range; for example, the range of " 1 to 5" includes 1, 1.4, 1.5, 3, 4, 5, 5.1, and 5, as well as other values. The word "comprising" is used herein to mean including whatever follows the word "comprising". Thus, the phrase "comprising A or B" means including A or B, or both A and B. The use of the alternative (e.g., "or", "either", "and / or") in the description for a particular embodiment shall not be construed to exclude the use of both conjunctive and disjunctive alternatives in the description for another particular embodiment.

[0035] Compared with the prior art, the present application has the beneficial technical effects of:

[0036] The compound of the present application has a high fluorescence quantum efficiency as a doping material, the parent nucleus structure is fused with a five-membered heterocycle at the central benzene ring, which enhances the rigidity, effectively inhibits the vibration coupling, narrows the FWHM, and improves the light-emitting efficiency of the device; in addition, the rigidity of the material is enhanced, which further increases the evaporation decomposition temperature, which is beneficial to inhibit the evaporation decomposition of the material and effectively improve the service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0038] Figure 1The nuclear magnetic resonance hydrogen spectrum of the compound L001 provided in the embodiments of the present application is shown in the following table. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0040] The embodiments of the present application disclose a boron-nitrogen-containing organic compound and an organic electroluminescent device comprising the same.

[0041] In addition, it should be noted that the numerical values given in the following embodiments are as accurate as possible, but a person skilled in the art understands that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, not an absolutely accurate number.

[0042] The following commonly known knowledge is referred to:

[0043] Transition Metal Organometallic Chemistry (6th Edition), Robert H. Crabtree, Publisher: Shanghai East China University of Technology Press, Publication Time: 2017-09-00, ISBN: 978-7-5628-5111-0, page 388.

[0044] Organic Chemistry and Optoelectronic Material Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Time: 2019-11-00, ISBN: 9787564184230, page 174.

[0045] The features and performances of the present application will be further described in detail below with specific reference to the embodiments.

[0046] Embodiment 1: Preparation of compound L001

[0047] (1) The raw material L001-a (1 eq, CAS: 1644282-00-7), the raw material L001-b (1 eq, CAS: 1993-03-9), potassium carbonate (1 eq), PdCl2 (0.001 eq), and TPPDA (0.001 eq) were added to o-xylene solution and mixed, and then added to a reaction container, and reacted at 100°C for 24 hours; cooled to room temperature, then slowly added saturated MgSO4 aqueous solution to the solution, and extracted with ethyl acetate three times, removed the solvent under reduced pressure, and the crude product was purified by column chromatography to obtain the intermediate L001-1 (yield 63%). (1) The raw material L001-a (1 eq, CAS: 1644282-00-7), the raw material L001-b (1 eq, CAS: 1993-03-9), potassium carbonate (1 eq), PdCl2 (0.001 eq), and TPPDA (0.001 eq) were added to o-xylene solution and mixed, and then added to a reaction container, and reacted at 100°C for 24 hours; cooled to room temperature, then slowly added saturated MgSO4 aqueous solution to the solution, and extracted with ethyl acetate three times, removed the solvent under reduced pressure, and the crude product was purified by column chromatography to obtain the intermediate L001-1 (yield 63%).

[0048] (2) Intermediate L001-1 (1 eq) and potassium carbonate (3 eq) were added to a reactor, which was purged with nitrogen three times, and DMAc was added as a solvent, which was purged with nitrogen three times, and stirred and warmed to 170°C for 9 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. Then, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate L001-2 (yield 67%).

[0049] (3) Intermediate L001-2 (1 eq), raw material L001-c (1 eq, CAS: 37500-95-1), cesium carbonate (2.5 eq) were added to a reaction vessel, and anhydrous DMF was added under nitrogen protection, and warmed to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. Then, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate L001-3 (yield 75%).

[0050] (4) Intermediate L001-3 (1 eq) was dissolved in tetrahydrofuran solution, and n-butyllithium (1.6M) n-hexane solution was slowly added at 0°C under nitrogen protection. After stirring at 0°C for 2 hours, raw material L001-d (1.08 eq, CAS: 486-25-9) was slowly added. Then the reaction mixture was slowly heated to room temperature and stirred for 12 hours. Dilute hydrochloric acid solution, distilled water and ethyl acetate were added to the reaction mixture, the aqueous layer was separated, extracted with ethyl acetate three times, the combined organic layer was dried with sodium sulfate, and filtered. After removing the solvent under reduced pressure, the crude product was dissolved in anhydrous dichloromethane, and then boron trifluoride ether was slowly added. The reaction mixture was stirred overnight, and then quenched with NaHCO3 aqueous solution. Then the aqueous layer was separated, extracted with dichloromethane, dried with sodium sulfate, filtered, and the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain intermediate L001-4 (yield 71%).

[0051] (5) Intermediate L001-4 (1 eq) was dissolved in tert-butylbenzene, tert-butyllithium in n-pentane was added slowly under nitrogen protection at 0 ℃, and the reaction mixture was stirred at 60 ℃ for 2 hours. After adding boron tribromide (2 eq) at 0 ℃, the reaction mixture was stirred at room temperature for 1 hour. N, N-diisopropylethylamine (DIPEA) (2.02 eq) was added at 0 ℃, and the reaction mixture was slowly warmed to room temperature. After stirring at 130 ℃ for 6 hours, the reaction mixture was cooled to room temperature. Methanol was added to the reaction mixture to remove residual BBr3. The mixture was separated, extracted with water and dichloromethane, and the combined organic layer was concentrated under reduced pressure. The crude product was purified by column chromatography to obtain the final product L001 (yield 28%, HPLC > 99%, mass spectrometry test value 892.68, elemental analysis: C, 87.31; H, 6.49; B, 1.27; N, 3.21; O, 1.83).

[0052] Nuclear magnetic resonance hydrogen spectrum (compound L001): as shown in Figure 1 .

[0053] The preparation method of the organic electroluminescent device is as follows:

[0054] (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was cleaned in distilled water for 2 times, ultrasonic washing for 30 minutes, and then repeatedly cleaned with distilled water for 2 times, ultrasonic washing for 10 minutes. After washing, methanol, acetone and isopropanol were sequentially ultrasonic washed (each for 5 minutes), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0055] (2) In the evaporation machine, a HIL was vacuum evaporated on the surface of the ITO anode obtained in step (1) to obtain a hole injection layer.

[0056] (3) A HTL was vacuum evaporated on the surface of the hole injection layer obtained in step (2) to form a hole transport layer.

[0057] (4) A light-emitting layer material was evaporated on the surface of the hole transport layer obtained in step (3), and a linear gradient co-evaporation was performed by a multi-source co-evaporation method to obtain a light-emitting layer with a thickness of 30 nm. The light-emitting layer comprises GH-1 and GH-2 as host materials, GD-1 as a first dopant material, and the compound of the present application as a second dopant material. The mass ratio of GH-1, GH-2, GD-1 and the compound of the present application is 66.5:30:3:0.5. The second dopant material is provided by the dopant materials of device examples 1-65, comparative examples 1-7 and parallel examples 1-5, respectively. ​

[0058] (5) The surface of the light-emitting layer obtained in step (4) is evaporated with HBL to form a hole-blocking layer with a thickness of 5 nm.

[0059] (6) The surface of the hole-blocking layer obtained in step (5) is evaporated with ETL to form an electron-transporting layer with a thickness of 30 nm.

[0060] (7) The surface of the electron-transporting layer obtained in step (6) is evaporated with LiF to form an electron-injecting layer with a thickness of 0.5 nm.

[0061] (8) The surface of the electron-injecting layer obtained in step (7) is evaporated with Al to form a cathode with a thickness of 150 nm, thereby obtaining the organic electroluminescent device.

[0062] The materials used in the functional layers of the device are as follows: .

[0063] Device Example 1-Device Example 65, Comparative Example 1-Comparative Example 7, and Parallel Example 1-Parallel Example 5:

[0064] Device Example 1-Device Example 65 use the second dopant material of the present application, as shown in Table 1.

[0065] Comparative Example 1-Comparative Example 7 use the structure of E as the second dopant material, and the structure of E is as follows: .

[0066] The driving voltage, luminous efficiency, and time taken for the luminance to decrease from 100% to 95% (lifetime; T95) of the organic electroluminescent device at a luminance of 15000 nits were tested, and the test results are shown in Table 1.

[0067] Table 1

[0068] The above experimental data show that, from the data of Comparative Example 1-Comparative Example 7 and Parallel Example 1-Parallel Example 5, the device lifetime of the compound of the present application in the single-doped system device is higher than that of the comparative compound; in the single-doped system device, the device efficiency also shows a good effect; compared with Parallel Example 1-Parallel Example 5, the compound of the present application in the double-doped system device using the exciton sensitization material as the first dopant has a greater improvement in the current efficiency and device lifetime of the device relative to the known material OLED device, and in the double-doped device, the device efficiency is also significantly improved compared with the single-doped device.

[0069] It can be known from the test results in the above table that the heterocyclic organic electroluminescent material with a new core has a wide band gap, balanced electrons and holes, and a stable structure due to the introduction of a weak acceptor boron atom and the cooperation of other heteroatoms, and the heterocyclic organic electroluminescent material based on the core has excellent spectral emission performance, and has more excellent performance in efficiency and service life than the existing technology containing a boron heterocyclic compound.

[0070] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A boron-nitrogen-containing organic compound, characterized in that, The general structural formula of the boron-nitrogen-containing organic compound is as follows: ； R1-R5 may be the same as or different from each other, and each is independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C60 silyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C2-C60 heterocyclic group, wherein the heteroatom in the heterocyclic group is selected from O, N or S; n1, n2, and n5 are each independent integers from 0 to 3; n3 is an integer independently of 0 to 4; n4 is an integer independently of 0 to 14; Any two adjacent groups in R1–R5 can bond with each other to form a ring; X is independently selected from one of the following: linker, O, S, Se, NR6, C(R7)(R8), Si(R7)(R8), and Ge(R7)(R8); R6, R7, and R8 may be the same or different, and each is independently selected from hydrogen, deuterium, methyl, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C7-C30 aralkyl, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C4-C30 heteroarylalkyl, substituted or unsubstituted C3-C30 heteroaryloxy, wherein the heteroatom is one or more of N, O, and S, and wherein R7 and R8 are connected to form a ring; Ring A indicates fusion with an adjacent benzene ring and is independently selected from the following groups: ； Indicates the fusion site with adjacent groups; R9-R 10 Each of the elements is independently selected from substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom in the heteroaryl is selected from O, N, or S, and the two are linked together to form a ring.

2. The boron-nitrogen-containing organic compound according to claim 1, characterized in that, General formula (1) has the compound structures shown in I-1 to I-18: 。 3. The boron-nitrogen-containing organic compound according to claim 1 or 2, characterized in that, R1-R5 are each independently selected from the following groups, which can be linked at any substitution site, and the following groups are further substituted with deuterium: 。 4. The boron-nitrogen-containing organic compound according to claim 1, characterized in that, The term "substitution" means substitution by a substituent selected from the following: deuterium, cyano, methyl, C2-C8 alkyl, C6-C24 aryl, C6-C24 heteroaryl, wherein the heteroaryl group comprises a monocyclic aromatic group or a polycyclic aromatic system with at least one heteroatom, and the heteroatom is one or more of O, S, and N; the hydrogen atom in the general formula (1) is unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium.

5. The boron-nitrogen-containing organic compound according to claim 1, characterized in that, The boron-nitrogen-containing organic compound is selected from any one of L001 to L888: 。 6. An organic electroluminescent device, characterized in that, Includes the boron-nitrogen-containing organic compounds as described in claim 1.

7. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer includes a light-emitting layer, which includes a first host material, a second host material, and a dopant material. At least one of the first host material and the second host material is a TADF material, and the dopant material is the boron-nitrogen organic compound.

8. The organic electroluminescent device according to claim 7, characterized in that, The light-emitting layer comprises a host material, an exciton-sensitizing material, and a dopant material. The exciton-sensitizing material is a complex containing a metal element, and the dopant material is the boron-nitrogen-containing organic compound.

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