Fused heterocyclic compound and organic electroluminescent device containing same

Abstract

The present invention discloses a fused heterocyclic compound and an organic electroluminescent device comprising the same, and mainly relates to an improvement of a BNN structure in which a diarylamine group is introduced to a para-position of boron to ensure narrowing of a spectral structure. Meanwhile, steric hindrance substituents such as alkyl, alkoxy or aryl are introduced to the meta-position of boron to increase the distortion of diarylamine groups in the whole structure, so that the electron cloud distribution of molecular HOMO on the diarylamine groups is reduced, the charge transfer state (CT state) of BNN molecules is weakened, the acromion is inhibited, and the luminous efficiency in the top emission structure is improved. In addition, the aggregation effect of molecules can be weakened by adding steric hindrance substituent groups, so that the service life of the device is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescence, and in particular to a condensed heterocyclic compound and an organic electroluminescent device containing the compound. Background Art

[0002] Organic light emitting devices (OLEDs) are current-driven thin-film devices with a sandwich-like structure, with a single or multiple layers of organic functional materials sandwiched between the anode and 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 injected into the hole transport layer and the electron transport layer respectively, and migrate to the light-emitting layer. When the two meet and recombine in the light-emitting layer, energy excitons are generated, thereby exciting the light-emitting molecules to finally produce visible light. OLEDs have the characteristics of self-luminescence, wide viewing angle, wide color gamut, and short response time. They can be made into large-size and / or flexible ultra-thin panels. They are a new display technology that is developing rapidly and has a high degree of process integration. They have been widely used in display products such as televisions, smart phones, tablets, car displays, and lighting, and will be further used in creative display products such as large-size displays and flexible screens.

[0003] In OLED devices, the materials that play a key role in luminous efficiency, device life and luminescent spectrum are the luminescent layer materials, especially the guest materials doped in the luminescent layer. Since the commercial products of blue light materials are still fluorescent materials, high efficiency is particularly important; in top-emitting blue light devices, the narrower the spectrum, the higher the efficiency under fixed color coordinates. The organic light-emitting materials with BNN structure show the characteristics of narrow spectrum and high efficiency. Therefore, technicians have invested a lot of resources in the development of organic light-emitting materials with BNN structure, hoping to continuously improve the performance of the products. In the BNN structure, connecting the diarylamine group at the para position of boron can effectively narrow the spectrum, but the diarylamine group has a strong electron-donating property, which makes the molecular HOMO have a larger electron cloud distribution in the diarylamine group, so that the BNN molecule exists in the CT state, which leads to a higher molecular shoulder peak and a greater loss of efficiency in the top emission structure. Summary of the invention

[0004] In the BNN structure of the present invention, in addition to connecting the diarylamine group at the para position of boron to ensure a narrower spectral structure, steric substituents such as alkyl, alkoxy or aryl are added at the meta position of boron to increase the torsion of the diarylamine group in the entire structure, reduce the electron cloud distribution of the molecular HOMO on the diarylamine group, weaken the CT state of the BNN molecule, thereby suppressing the shoulder peak and improving the light extraction efficiency in the top emission structure. In addition, the addition of steric substituents can weaken the aggregation of molecules, thereby increasing the life of the device. Specifically, the present invention provides:

[0005] 1) A fused heterocyclic compound, wherein the fused heterocyclic compound is represented by the following general formula (1):

[0006]

[0007] Wherein, X is O, S or Se;

[0008] R1, R2, Ar1, Ar2 are each independently selected from a substituted or unsubstituted aryl group having 6 to 50 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 50 carbon atoms; preferably a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms;

[0009] R3 and R4 are each independently selected from the group consisting of hydrogen, deuterated or undeuterated substituents: substituted or unsubstituted alkyl having 1 to 50 carbon atoms, substituted or unsubstituted silyl, substituted or unsubstituted alkoxy having 1 to 50 carbon atoms, substituted or unsubstituted aryl having 6 to 50 carbon atoms, or substituted or unsubstituted heteroaryl having 2 to 50 carbon atoms. R3 is preferably methyl, isopropyl, tert-butyl, adamantyl, methoxy, tert-butylmethoxy, phenyl, naphthyl, dimethyl-tert-butylsilyl, and deuterated methyl, deuterated tert-butyl, and deuterated phenyl.

[0010] R5 and R6 are each independently hydrogen, a deuterated or undeuterated substituent selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, and a substituted or unsubstituted phenyl group, and R5 and R6 are not hydrogen at the same time.

[0011] 2) According to the fused heterocyclic compound for an organic electroluminescent device described in 1) above, the "substituted" in the "substituted or unsubstituted" in the compound means that the substituent is independently selected from a deuterium atom, a tritium atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a monovalent alkyl group or a cycloalkyl group having 1 to 10 carbon atoms, a monovalent monocyclic aromatic group or a condensed aromatic group having 6 to 30 carbon atoms, and a monovalent heterocyclic group or a condensed heteroaryl group having 2 to 50 carbon atoms.

[0012] 3) The fused heterocyclic compound for an organic electroluminescent device according to 1) or 2) above, wherein R4 is selected from tert-butyl and 1,3,5-trimethylphenyl.

[0013] 4) A fused heterocyclic compound for an organic electroluminescent device according to any one of 1) to 3) above, wherein R5 and R6 are each independently selected from methyl, isopropyl, tert-butyl, methoxy, tert-butyloxy, phenyl, deuterated methyl, deuterated tert-butyl, deuterated isopropyl, and deuterated phenyl.

[0014] 5) The fused heterocyclic compound for an organic electroluminescent device according to claim 1, characterized in that the biscarbazopyrene compound is selected from the following structures:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] 6) An organic electroluminescent device, wherein the organic electroluminescent device comprises an anode, a cathode and at least one organic thin film located between the anode and the cathode, and the organic thin film contains the compound according to any one of 1) to 5) above.

[0029] 7). The organic electroluminescent device according to 6) above, wherein the compound is used as a light-emitting material in the organic electroluminescent device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device to which the compound of the present invention is applied, wherein the meanings of the various layers of the device structure are as follows:

[0032] 1. Transparent substrate layer, 2. ITO anode layer, 3. Hole injection layer, 4. Hole transport layer A, 5. Hole transport layer B (or electron blocking layer), 6. Light-emitting layer, 7. Electron transport layer B (or hole blocking layer), 8. Electron transport layer A, 9. Electron injection layer, 10. Cathode reflective electrode layer. DETAILED DESCRIPTION

[0033] the term

[0034] In the present invention, the alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, and is, for example, 1 to 50, preferably 1 to 20, and more preferably 1 to 6. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, isohexyl, 4-methylhexyl, and 5-methylhexyl.

[0035] Alkoxy refers to -O-alkyl, wherein the number of carbon atoms is not particularly limited, for example, 1 to 50, preferably 1 to 20, more preferably 1 to 6. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, propoxy (eg, n-propoxy and isopropoxy), and tert-butoxy.

[0036] In the present invention, the above-mentioned alkyl or alkoxy group may be substituted. For example, in the fluorinated alkyl group and the fluorinated alkoxy group substituted with fluorine, the number of carbon atoms is not particularly limited, for example, 1 to 20, more preferably 1 to 6. Examples of fluorinated alkyl groups include, but are not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, trichloromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, and heptafluoropropyl. Examples of fluorinated alkoxy groups include, but are not limited to, trifluoromethoxy, 2,2,2-trifluoroethoxy, and pentafluoroethoxy.

[0037] The cycloalkyl group may be a monocyclic ring or a condensed ring, and the number of carbon atoms therein is not particularly limited, and is, for example, 3 to 50, preferably 3 to 20, and more preferably 3 to 6. Specific examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and adamantyl, and cyclohexyl is preferred.

[0038] The aryl group may be a monocyclic or polycyclic aryl group, wherein the number of carbon atoms is not particularly limited, for example, 6 to 50, preferably 6 to 20. Examples of monocyclic aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl and terphenyl. Examples of polycyclic aryl groups include naphthyl, anthracenyl, phenanthrenyl, pyrenyl, perylenyl, naphthylene, fluorenyl, acenaphthenyl, triphenylene and fluoranthenyl, but the scope of the present invention is not limited thereto.

[0039] The arylamine group is an amine group substituted with an aryl group. Examples of arylamine groups include substituted or unsubstituted monoarylamine groups, substituted or unsubstituted diarylamine groups, and substituted or unsubstituted triarylamine groups. The aryl group in the arylamine group can be a monocyclic or polycyclic aryl group. The arylamine group can contain two or more aryl groups. In this case, the aryl group can be a monocyclic aryl group or a polycyclic aryl group. Alternatively, the aryl group can be composed of a monocyclic aryl group and a polycyclic aryl group. The aryl group in the arylamine group can be selected from those exemplified above. Specific examples of the arylamino group include phenylamino, naphthylamino, biphenylamino, anthracenylamino, diphenylamino, N-phenylnaphthylamino, xylylamino, N-phenyltolylamino, N-phenylbiphenylamino, N-phenylnaphthylamino, N-biphenylnaphthylamino, N-naphthylfluorenylamino, N-phenylphenanthrenylamino, N-biphenylphenanthrenylamino, N-phenylfluorenylamino, N-phenylterphenylamino, N-phenanthrenylfluorenylamino, and N-biphenylfluorenylamino. The substituted diphenylamino groups in the present invention include the above-mentioned N-phenylnaphthylamino, xylylamino, N-phenyltolylamino, N-phenylbiphenylamino, N-phenylnaphthylamino, N-biphenylnaphthylamino, N-naphthylfluorenylamino, N-phenylphenanthrenylamino, N-biphenylphenanthrenylamino, N-phenylfluorenylamino, N-phenylterphenylamino, N-phenanthrenylfluorenylamino, and N-biphenylfluorenylamino.

[0040] "Heterocyclyl" refers to a cyclic compound group in which one or more atoms in the ring are replaced by heteroatoms other than carbon (such as nitrogen, oxygen, sulfur, etc.). A fused-ring heteroaryl group refers to a cyclic compound group in which at least two rings (at least one of which is an aromatic ring) share one or more carbon atoms, and at least one ring contains one or more heteroatoms. Examples of heterocyclic groups and fused-ring heteroaryl groups include, but are not limited to, thienyl, furanyl, pyrrolyl, imidazolyl, triazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, triazolyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, benzofuranyl, dibenzofuranyl, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, benzothiazolyl, and phenothiazinyl.

[0041] Silyl is intended to include alkyl-substituted silyl and aryl-substituted silyl. Specific examples of such silyl include trimethylsilyl, triethylsilyl, triphenylsilyl, trimethoxysilyl, dimethoxyphenylsilyl, diphenylmethylsilyl, diphenylvinylsilyl, methylcyclobutylsilyl, and dimethylfurylsilyl.

[0042] "Deuterated" or "deuterated or not deuterated" refers to one or more deuterated or fully deuterated.

[0043] The specific synthesis steps are as follows:

[0044] Synthesis Example 1

[0045] Synthesis of intermediate M002-1

[0046]

[0047] C002-1 (10.25 g, 50 mmol), C002-2 (14.05 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (0.92 g, 1.0 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (0.82 g, 2.0 mmol), sodium tert-butoxide (9.61 g, 100 mmol) were added to a 500 mL flask. The reaction system was ventilated three times, nitrogen was protected, and 200 ml of toluene was added. Under nitrogen protection, heated and stirred, reacted at 105 ° C for 12 h. Stop the reaction, cool to room temperature, add 200 ml of deionized water, and transfer the reaction solution to a separatory funnel for extraction and separation. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product M002-1, 17.82 g solid, with a yield of 88%; the molecular weight measured by liquid chromatography-mass spectrometry was m / z=405;

[0048] Synthesis of intermediate M002-2

[0049]

[0050] C002-3 (5.96 g, 40 mmol), M002-1 (16.20 g, 40 mmol), tri(dibenzylideneacetone)dipalladium (0.73 g, 0.80 mmol), sodium tert-butoxide (7.68 g, 80 mmol) were added to a 250 mL flask. The reaction system was ventilated three times with nitrogen protection. Then, a toluene solution (1 mol / L) of tri-tert-butylphosphine and 150 ml of toluene were added with a syringe (3.2 mL, 3.20 mmol). Under nitrogen protection, heat and stir, and react at 105 ° C for 12 h. Stop the reaction, cool to room temperature, add 200 ml of deionized water, and transfer the reaction solution to a separatory funnel for extraction and separation. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product M002-2, 16.36 g solid, with a yield of 79%; the molecular weight measured by liquid chromatography-mass spectrometry was m / z=518;

[0051] Synthesis of intermediate M002-3

[0052]

[0053] C002-4 (13.50 g, 50 mmol), C002-5 (7.45 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (0.92 g, 1.0 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (0.82 g, 2.0 mmol), sodium tert-butoxide (9.61 g, 100 mmol) were added to a 500 mL flask. The reaction system was ventilated three times, nitrogen was protected, and 200 ml of toluene was added. Under nitrogen protection, heated and stirred, reacted at 100 ° C for 12 h. Stop the reaction, cool to room temperature, add 200 ml of deionized water, and transfer the reaction solution to a separatory funnel for extraction and separation. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product M002-3, 12.81 g solid, with a yield of 76%; the molecular weight measured by liquid chromatography-mass spectrometry was m / z=337;

[0054] Synthesis of intermediate M002-4

[0055]

[0056] C002-6 (6.72 g, 30 mmol), M002-2 (15.54 g, 30 mmol), tri(dibenzylideneacetone)dipalladium (0.55 g, 0.60 mmol), sodium tert-butoxide (5.76 g, 60 mmol) were added to a 250 mL flask. The reaction system was ventilated three times with nitrogen protection. Then, a toluene solution (1 mol / L) of tri-tert-butylphosphine and 100 ml of toluene were added with a syringe (2.4 mL, 2.40 mmol). Under nitrogen protection, heat and stir, and react at 105 ° C for 12 h. Stop the reaction, cool to room temperature, add 100 ml of deionized water, and transfer the reaction solution to a separatory funnel for extraction and separation. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product M002-4, 16.33 g solid, with a yield of 82%; the molecular weight measured by liquid chromatography-mass spectrometry was m / z=664;

[0057] Synthesis of intermediate M002-5:

[0058]

[0059] M002-3 (6.74 g, 20 mmol), M002-4 (13.24 g, 20 mmol), tri(dibenzylideneacetone)dipalladium (0.36 g, 0.40 mmol), sodium tert-butoxide (3.84 g, 40 mmol). The reaction system was ventilated three times and protected by nitrogen. Then, a toluene solution (1.6 mL, 1.60 mmol) of tri-tert-butylphosphine and 100 ml of xylene were added with a syringe. Under nitrogen protection, heated and stirred, reacted at 140 ° C for 12 h. Stop the reaction, cool to room temperature, add 100 ml of deionized water, and transfer the reaction solution to a separatory funnel for extraction and separation. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product M002-5, 11.97 g solid, with a yield of 62%; the molecular weight measured by liquid phase mass spectrometry was m / z = 965; Synthesis of product D002:

[0060]

[0061] Under nitrogen protection, intermediate M002-5 (9.65g, 10mmol) was added to 40mL tert-butylbenzene, and tert-butyl lithium (11.6mL, 15mmol, 1.3M) was added dropwise thereto at -78°C. After the addition was completed, the mixture was stirred at 60°C for 3 hours. After boron tribromide (5.02g, 20mmol) was added dropwise at -78°C, the resulting mixture was stirred at room temperature for 1 hour, and N, N-diisopropylethylamine (3.96g, 30mmol) was added dropwise thereto at 0°C. After the addition was completed, the mixture was stirred at 120°C for 2 hours. The reaction was stopped, cooled to room temperature, 100ml deionized water was added, and the reaction solution was transferred to a separatory funnel and extracted and separated. The extract was dried over anhydrous magnesium sulfate and concentrated, and the sample was purified by silica gel column chromatography to obtain product D002, 2.0 g of yellow solid, with a yield of 21%; the molecular weight measured by liquid chromatography-mass spectrometry was m / z=954.

[0062] Table 1

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] Device Example: Fabrication of Organic Electroluminescent Devices Used as Light Emitting Materials

[0069] A 50mm×50mm×0.7mm thick glass substrate with an indium tin oxide / silver / indium tin oxide (ITO / Ag / ITO) anode was ultrasonically cleaned in isopropyl alcohol for 5 minutes. The cleaned glass substrate was installed on the substrate rack of a vacuum evaporation device, evacuated to 1×10-5~1×10-6Pa, and treated with nitrogen plasma for 120 seconds before evaporating the organic material. Then HT and PD as a doping were co-evaporated on the anode as a hole injection layer (HIL) with a film thickness of 10nm, where the doping concentration of PD was 3%. HT was evaporated on top of the hole injection layer as a hole transport layer (HTL) with a film thickness of 132nm. Subsequently, EB was evaporated on top of the hole transport layer as an electron blocking layer (EBL) with a film thickness of 5nm. Then, a light-emitting layer (EML) is co-deposited on the electron blocking layer with a thickness of 20 nm; the main material and the light-emitting material (BH and D002) of the light-emitting layer are evaporated by multi-source co-evaporation, wherein the doping concentration of the light-emitting material is 1.5%. Then HB is evaporated on the light-emitting layer as a hole blocking layer (HBL) with a thickness of 5 nm. Then, on the hole blocking layer, an electron transport material (ET) and 8-hydroxyquinoline lithium (Liq) are co-evaporated in a 1:1 ratio as an electron transport layer (ETL) with a thickness of 30 nm. In addition, LiF is evaporated on the ETL as an electron injection layer (EIL) with a thickness of 1 nm. Then, cathode metal magnesium / silver (Mg / Ag) is co-evaporated on the EIL with a thickness of 13.2 nm, wherein the doping concentration of magnesium is 10%. Finally, CP is evaporated as a light coupling extraction layer (CPL) with a thickness of 65 nm. The fabricated device is transferred to a glove box and encapsulated with a glass cover. The structure of the organic electroluminescent device of Example 1 is as follows Figure 1 As shown, Figure 1 The stacking order and role of each functional layer are also shown.

[0070] The OLED has the following layer structure in principle: ITO / Ag / ITO substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / luminescent layer (EML) / hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) / cathode / light coupling extraction layer (CPL). The exact structure of the OLED is shown in Table 2.

[0071] Table 2 Materials used for OLED

[0072]

[0073] Device Example 1 :

[0074] ITO / Ag / ITO / HT:PD(10nm,3%) / HT(132nm) / EB(5nm) / BH:D002(20nm,1.5%) / HB(5nm) / ET:Liq(30nm,50%) / LiF(1nm) / Ag:Mg(13.2nm,10%) / CP(65nm)

[0075] The only difference between device examples 2-40 and device example 1 is that D002 of the present invention used in the light-emitting layer is replaced by other compounds of the present invention. The performance test data of the obtained devices are shown in Table 3.

[0076] Comparative Examples 1 to 2:

[0077] Compared with device embodiment 1, this comparative example is different in that D002 in the organic electroluminescent device is changed to BD-1 and BD-2 which are well known in the industry and have been commercially applied. The obtained device performance test data are shown in Table 3.

[0078] The OLED is characterized by standard methods. For this purpose, the electroluminescence spectrum, half-peak width, current efficiency (measured in cd / A), power efficiency (measured in lm / W) and external quantum efficiency (EQE, measured in %) and color coordinates (CIEx, CIEy) are determined, which are calculated as a function of the luminous density from the current / voltage / luminous density characteristic line (IUL characteristic line) showing Lambertian emission characteristics. The blue light index BI represents the current efficiency / CIEy at 10mA / cm2, T95 represents the operating time of the device at a starting brightness of 20mA / cm2 when the device brightness decreases to 95%, and the FWHM value represents the half-peak width of the spectrum of the device at 10mA / cm2. The device performances of Examples 1 to 40 of the present invention and Comparative Examples 1 to 2 are summarized as shown in Table 3;

[0079] Table 3 Device performance

[0080]

[0081]

[0082] As can be seen from Table 3, compared with the prior art, the use of material embodiments 1-40 of the present invention can improve the device life while narrowing the spectrum and improving the device efficiency. Compared with Comparative Example 2, the FWHM of D067 in device embodiment 16 is narrowed by 0.7nm, the efficiency is improved by 5.7%, and the life is also improved by 20.2%. After partial structural deuteration on the molecule, the device life is improved to a certain extent, such as device embodiment 39, relative to comparative example 2, the efficiency is improved by 6.7%, and the life is improved by 40.4%; relative to the unsubstituted device embodiment 31, the life is improved by 18.7%.

[0083] In the BNN structure, in addition to connecting the diarylamine group at the para position of boron to ensure a narrow spectral structure, a steric substituent such as an alkyl, alkoxy or aryl group is added at the meta position of boron to increase the torsion of the diarylamine group in the entire structure, reduce the electron cloud distribution of the molecular HOMO on the diarylamine group, weaken the CT state of the BNN molecule, thereby suppressing the shoulder peak and improving the light extraction efficiency in the top emission structure. In addition, the addition of the steric substituent group can weaken the aggregation of molecules, thereby improving the life of the device.

Claims

1. A fused heterocyclic compound, characterized in that: The fused heterocyclic compound is represented by the following general formula (1): Wherein, X is O, S or Se; R1, R2, Ar1, Ar2 are each independently selected from a substituted or unsubstituted aryl group having 6 to 50 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 50 carbon atoms; R3 and R4 are each independently selected from the group consisting of hydrogen, deuterated or undeuterated substituents: substituted or unsubstituted alkyl having 1 to 50 carbon atoms, substituted or unsubstituted silyl, substituted or unsubstituted alkoxy having 1 to 50 carbon atoms, substituted or unsubstituted aryl having 6 to 50 carbon atoms, or substituted or unsubstituted heteroaryl having 2 to 50 carbon atoms; R5 and R6 are each independently selected from the group consisting of hydrogen, deuterated or undeuterated substituents: substituted or unsubstituted alkyl having 1 to 50 carbon atoms, substituted or unsubstituted alkoxy having 1 to 50 carbon atoms, and substituted or unsubstituted phenyl, and R5 and R6 are not hydrogen at the same time.

2. The fused heterocyclic compound for an organic electroluminescent device according to claim 1, characterized in that: The "substituted" in the "substituted or unsubstituted" in the compound means that the substituent is independently selected from a deuterium atom, a tritium atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a monovalent alkyl group or a cycloalkyl group having 1 to 10 carbon atoms, a monovalent monocyclic aromatic group or a condensed aromatic group having 6 to 30 carbon atoms, and a monovalent heterocyclic group or a condensed heteroaryl group having 2 to 50 carbon atoms.

3. The fused heterocyclic compound for an organic electroluminescent device according to claim 1 or 2, characterized in that: The R4 is selected from tert-butyl and 1,3,5-trimethylphenyl.

4. The fused heterocyclic compound for an organic electroluminescent device according to any one of claims 1 to 3, characterized in that: The R5 and R6 are each independently selected from methyl, isopropyl, tert-butyl, methoxy, tert-butyloxy, phenyl, deuterated methyl, deuterated tert-butyl, deuterated isopropyl, and deuterated phenyl.

5. The fused heterocyclic compound for an organic electroluminescent device according to claim 1, characterized in that: The fused heterocyclic compound is selected from the following structures:

6. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and at least one organic thin film between the anode and the cathode, wherein the organic thin film contains the compound according to any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, characterized in that: The compound is used as a light-emitting material in an organic electroluminescent device.

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