Polycyclic aromatic compound and organic electroluminescent device adopting same

Abstract

The invention provides a polycyclic aromatic compound and an organic electroluminescent device adopting the same, and belongs to the field of organic photoelectric materials, and the polycyclic aromatic compound has a structure as shown in a formula I. After the polycyclic aromatic compound provided by the invention is applied to the organic electroluminescent device, the organic electroluminescent device has a good application prospect. Meanwhile, the luminous efficiency of the device is improved, and the service life is prolonged.

Description

[0001] This application is a divisional application of patent application number 202510450937.7, the original application being filed on April 11, 2025, entitled "A Polycyclic Aromatic Compound and an Organic Electroluminescent Device Using Such Compounds"—applied to the divisional application. Technical Field

[0002] This invention belongs to the field of organic optoelectronic materials, specifically relating to a polycyclic aromatic compound and an organic electroluminescent device using such a compound. Background Technology

[0003] Organic light-emitting diodes (OLEDs) are electroluminescent devices formed from multilayer organic thin-film structures. Due to their numerous advantages, such as flexibility, fast response speed, wide viewing angle, small size, high brightness, and vibrant colors, they have gradually entered the public eye as a novel and promising display technology. Currently, OLEDs are widely used in displays such as smartphones, smartwatches, tablets, and televisions, as well as in solid-state lighting.

[0004] In the fields of displays and solid-state lighting, the core of OLED display technology is organic light-emitting materials, which achieve full-color gamut emission based on the mixing of red, green, and blue light-emitting materials. The development of novel light-emitting materials is the driving force behind the continuous advancement of electroluminescence technology and a research hotspot in the organic electroluminescence industry. Currently, many red and green light emitters have been developed and are widely used in commercial OLED products. However, there is less development of novel blue organic electroluminescent materials with narrow half-width, high color purity, high luminous efficiency, and superior luminous lifetime. Therefore, developing a novel blue organic electroluminescent material with high luminous efficiency, long lifetime, narrow half-width, and high color purity has become a research hotspot.

[0005] Currently, the mainstream approach is to construct polycyclic aromatic compounds formed by the condensation of multiple aromatic rings with boron atoms and heteroatoms such as nitrogen and oxygen, and to utilize the multiple vibrational effect (MR effect) to prepare novel blue organic electroluminescent materials containing boron atoms and nitrogen-oxygen heteroatoms, thus creating a special rigid material system. These fluorescent molecules exhibit high radiative transition rates, narrow full width at half maximum (FWHM), and high color purity, but their performance in device lifetime and luminous efficiency is not particularly ideal. Furthermore, the industrialization of this technology still faces many key challenges. Therefore, developing new materials remains a pressing issue for those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a polycyclic aromatic compound and an organic electroluminescent device using such a compound. The polycyclic aromatic compound provided by the present invention has the advantage of simultaneously improving the luminous efficiency and extending the lifespan of the device when used in organic electroluminescent devices.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] On one hand, the present invention provides a polycyclic aromatic compound having the structure shown in Formula I:

[0009]

[0010] In formula I, Y is selected from R, , ;

[0011] R represents hydrogen, deuterium, -F, -Cl, -Br, -I, -SF5, hydroxyl, cyano, nitro, amino, amido, hydrazine, hydrazone, carboxylic acid or its salt, sulfonic acid or its salt, phosphate or its salt, substituted or unsubstituted C1-C60 alkyl, substituted or unsubstituted C2-C60 alkenyl, substituted or unsubstituted C2-C60 alkynyl, substituted or unsubstituted C1-C60 alkoxy, substituted or unsubstituted C1-C60 alkylthio, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 heterocyclic alkyl, substituted or unsubstituted C3-C10 cycloalkyl. Alkenyl, substituted or unsubstituted C1-C10 heterocyclic alkenyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 arylthio, substituted or unsubstituted C1-C60 heteroaryl, substituted or unsubstituted monovalent non-aromatic fused polycyclic groups, substituted or unsubstituted monovalent non-aromatic heterofused polycyclic groups, Si(Q1)(Q2)(Q3), -Ge(Q1)(Q2)(Q3), -B(Q4)(Q5), -P(=O)(Q6)(Q7), or -P(Q6)(Q7);

[0012] Each of Q1 to Q7 above is independently hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; amidine; hydrazine; hydrazone; carboxylic acid group or its salt; sulfonic acid group or its salt; phosphate group or its salt; C1-C30 alkyl, C2-C30 alkenyl, C2-C30 alkynyl, C1-C30 aryl, deuterated C6-C30 aryl, fluoroC6-C30 aryl or any combination thereof, substituted or unsubstituted, C1-C30 alkyl, C2-C30 alkenyl, C2-C30 alkoxy, C3-C10 cycloalkyl, C1-C10 heterocyclic alkyl, C3-C10 cycloalkenyl or C1-C10 heterocyclic alkenyl; substituted with deuterium, -F, cyano, C1-C30 alkyl, deuterated C1-C30 Alkyl, fluorinated C1-C30 alkyl, C6-C30 aryl, deuterated C6-C30 aryl, fluorinated C6-C30 aryl or any combination thereof substituted or unsubstituted C6-C30 aryl, C1-C30 heteroaryl, C6-C30 aryloxy or C6-C30 arylthio; monovalent non-aromatic fused polycyclic groups; or monovalent non-aromatic heterofused polycyclic groups;

[0013] X1 and X2 are selected independently from... , X1 and X2 can be the same or different;

[0014] R1-R8 are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -SF5, hydroxyl, cyano, CF3, nitro, amino, trimethylsilyl, trimethylgermanyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, and their heteroatoms contain at least one of O, S, N, Si, Ge or Se;

[0015] X3 and X4 are selected independently from... , , , , , , , X3 and X4 can be the same or different, and * represents the linkage site of the group.

[0016] in, , , or The two Rs in a At least one of them is selected from F, and the other is R. a Then it is Rc;

[0017] , , , or The two Rs b At least one of them is a substituent that is not hydrogen or deuterium, and the other is R b Then it is R c ;

[0018] Where R a R b and R c Each is independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermanyl, substituted or unsubstituted C1-C6 alkyl, phenyl, biphenyl or naphthyl;

[0019] m can be independently selected from 0, 1, 2, 3, 4, or 5;

[0020] In Formula I, all hydrogen atoms are either substituted with deuterium or not substituted with deuterium.

[0021] Preferably, the polycyclic aromatic compounds have the compound structures shown in I-1 to I-3:

[0022] .

[0023] In Equations I-1 to I-3, all hydrogen atoms are either substituted with or not substituted with deuterium.

[0024] Preferably, R1-R8 are each independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermanium, substituted or unsubstituted C1-C6 alkyl, phenyl, biphenyl or naphthyl.

[0025] In this invention, the terms "substituted or unsubstituted C1-C60 alkyl", "substituted or unsubstituted C2-C60 alkenyl", "substituted or unsubstituted C2-C60 alkynyl", "substituted or unsubstituted C1-C60 alkoxy", "substituted or unsubstituted C1-C60 alkylthiol", "substituted or unsubstituted C3-C10 cycloalkyl", "substituted or unsubstituted C1-C10 heterocyclic alkyl", "substituted or unsubstituted C3-C10 cycloalkenyl", "substituted or unsubstituted C1-C10 heterocyclic alkenyl", "substituted or unsubstituted C6-C60 aryl", "substituted or unsubstituted C6-C60 aryloxy", "substituted or unsubstituted C6-C60 aryloxy", and "substituted or unsubstituted C6-C60 aryloxy" are used interchangeably with the terminology used in this invention. "Thioyl", "substituted or unsubstituted C6-C60 arylthio", "substituted or unsubstituted C6-C60 arylthio", "substituted or unsubstituted C1-C60 heteroaryl", "substituted or unsubstituted C1-C30 alkyl", "substituted or unsubstituted C1-C30 alkyl", "substituted or unsubstituted C2-C30 alkenyl", "substituted or unsubstituted C2-C30 alkynyl", "substituted or unsubstituted C1-C30 alkoxy", "substituted or unsubstituted C1-C30 alkylthio", "substituted or unsubstituted C3-C10 cycloalkyl", "substituted or unsubstituted C1-C10 heterocyclic alkyl", "substituted or unsubstituted C3-C10 cycloalkenyl", "substituted or unsubstituted C1-C10 heterocyclic alkenyl", Substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C6-C30 arylthio, substituted or unsubstituted C6-C30 arylthio, substituted or unsubstituted C6-C30 arylthio, substituted or unsubstituted C1-C30 heteroaryl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C2-C15 alkenyl, substituted or unsubstituted C2-C15 alkynyl, substituted or unsubstituted C1-C15 alkoxy, substituted or unsubstituted C1-C24 alkylthio, substituted or unsubstituted C The following are categories of alkyl, alkenyl, alkoxy, and alkylthio groups in the categories "3-C6 cycloalkyl", "substituted or unsubstituted C1-C6 heterocycloalkyl", "substituted or unsubstituted C3-C6 cycloalkenyl", "substituted or unsubstituted C1-C6 heterocycloalkenyl", "substituted or unsubstituted C6-C24 aryl", "substituted or unsubstituted C6-C24 aryloxy", "substituted or unsubstituted C6-C24 aryloxy", "substituted or unsubstituted C6-C24 arylthio", "substituted or unsubstituted C6-C24 arylthio", "substituted or unsubstituted C1-C24 heteroaryl", "substituted or unsubstituted C1-C30 alkyl", and "substituted or unsubstituted C1-C6 alkyl".The carbon number of cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, aryl, aryloxy, and arylthio groups indicates the total number of carbon atoms constituting the unsubstituted aryl or unsubstituted alkyl group, or the total number of carbon atoms constituting the heteroaryl group, without considering the number of carbon atoms in the substituents.

[0026] Preferably, "substitution" means substitution by a substituent selected from one or more of the following groups linked together: hydrogen, deuterium, halogen, cyano, trimethylsilyl (TMS), trimethylgermanium, trifluoromethyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, phenyl, naphthyl, anthracene, phenanthrene, thiophene, furanyl, pyrrole, benzothiophene, benzofuranyl, pyridyl, indolyl, cyclopentyl, cyclohexyl, adamantyl.

[0027] Preferably, the polycyclic aromatic compound is selected from any one of the following compounds:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] .

[0040] The organic electroluminescent compounds of the present invention can be prepared by synthetic methods known to those skilled in the art. For example, the following reaction process is preferred for preparation.

[0041]

[0042] The restrictions on the groups in the above formula are the same as those mentioned above, and will not be repeated here.

[0043] Step 1 specifically includes the following steps: Under nitrogen protection, raw material A (1.3-1.4 eq) and raw material B (1.0 eq) are dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 90-110℃, and refluxed for 4-6 h; after the reaction is completed, the temperature is slightly lowered, and the mixture is filtered with diatomaceous earth to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed three times with water, and the organic phase is retained. Then, the aqueous phase is extracted with ethyl acetate; after combining the organic phases, the mixture is dried with anhydrous magnesium sulfate, and the solvent is removed using a rotary evaporator. The mixture is then dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is washed multiple times with petroleum ether and dried in a 60℃ oven for 5 h to obtain intermediate 1;

[0044] Step 2 specifically includes the following steps: Under nitrogen protection, raw material C (1.3-1.4 eq) and raw material D (1.0 eq) are dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 90-110℃, and refluxed for 4-6 h; after the reaction is completed, the temperature is slightly lowered, and the mixture is filtered with diatomaceous earth to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed three times with water, and the organic phase is retained. Then, the aqueous phase is extracted with ethyl acetate; after combining the organic phases, the mixture is dried with anhydrous magnesium sulfate, and the solvent is removed using a rotary evaporator. The mixture is then dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is washed multiple times with petroleum ether and dried in a 60℃ oven for 5 h to obtain intermediate 2;

[0045] Step 3 specifically includes the following steps:

[0046] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, and sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added. The mixture was stirred until homogeneous, heated to 90-120℃, and refluxed for 8-12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. The filtrate was cooled to room temperature and washed three times with water, retaining the organic phase. The aqueous phase was then extracted with ethyl acetate. The organic phases were combined and dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was washed multiple times with petroleum ether and dried in a 60℃ oven for 5 h to obtain intermediate 3.

[0047] Step 4 specifically includes the following steps:

[0048] Under nitrogen protection, intermediates 2 (1.0 eq) and 3 (1.0 eq) were dissolved in toluene solution, and sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added. The mixture was stirred until homogeneous, heated to 90-120 °C, and refluxed for 8-12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. The filtrate was cooled to room temperature and washed three times with water, retaining the organic phase. The aqueous phase was then extracted with ethyl acetate. The organic phases were combined and dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was washed multiple times with petroleum ether and dried in a 60 °C oven for 5 h to obtain intermediate 4.

[0049] Step 5 specifically includes the following steps:

[0050] Under nitrogen protection, intermediate 4 (1.0 eq) was dissolved in 1,2-dichlorobenzene, and boron triiodide (1.5-1.6 eq) was added. The mixture was stirred until homogeneous, heated to 130-150 °C, and refluxed for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and diisopropylamine (5.0 eq) was added to the reaction mixture. After stirring for 1-2 h, excess petroleum ether was added, and stirring was continued for 12-14 h. A solid precipitated and was filtered. The collected solid was dried in a 60 °C oven for 5 h. The remaining substance was then purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 10:4) to obtain compound I.

[0051] On the other hand, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising the polycyclic aromatic compounds as described above.

[0052] Preferably, the organic thin film layer includes a light-emitting layer, which includes a host material and a dopant material, wherein the dopant material includes polycyclic aromatic compounds as described above.

[0053] Preferably, the organic thin film layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, or an electron injection layer.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The polycyclic aromatic compounds of this invention introduce aromatic amines or carbazoles into the parent core. Excessive phenyl groups in these compounds increase packing density and steric hindrance, affecting deposition temperature and consequently reducing luminescence efficiency and lifetime. Carbazoles, due to their strong conjugation properties, improve intermolecular stacking and increase horizontal molecular alignment, effectively increasing luminescence efficiency. When all aromatic amine groups are aryl-substituted, the energy levels are lower, preventing carrier migration localization and reducing the hole transport barrier, thus increasing migration rate and luminescence efficiency. Introducing fluorine further lowers the HOMO and LUMO energy levels of organic compounds, enhancing charge carrier mobility and strengthening intermolecular electrostatic forces, resulting in better material stability and significantly improved device lifetime. Devices fabricated using the doped materials of this invention exhibit significantly improved lifetime and efficiency. Attached Figure Description

[0056] Figure 1 The image shows the proton NMR spectrum of compound 114. Detailed Implementation

[0057] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0058] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible. However, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0059] The following are common knowledge references:

[0060] Organometallic Chemistry (6th Edition), Robert H. Crabtree, published by East China University of Science and Technology Press, Shanghai, September 00, 2017, ISBN: 978-7-5628-5111-0, page 388.

[0061] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0062] Example 1

[0063]

[0064] Since there is no existing technology for raw material A-114, the following synthetic route was adopted for synthesis:

[0065] .

[0066] Under nitrogen atmosphere, raw material a-114 (1.0 eq, CAS No.: 98-80-6) and raw material b-114 (1.0 eq, CAS No.: 67567-26-4) were added to a mixed solution of toluene, ethanol and water in a volume ratio of 2:1:1. Potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) were added to the solution. The mixture was stirred until homogeneous, heated to 85°C and refluxed for 4 h. After the reaction was completed, the temperature was slightly lowered, and the solution was filtered with diatomaceous earth to remove salts and catalysts. The filtrate was cooled to room temperature and washed three times with water, retaining the organic phase. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. The solution was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether as the eluent to obtain raw material A-114 (yield: 63.7%).

[0067] Step 1 specifically includes the following steps: Under nitrogen protection, raw material A-114 (1.4 eq) and raw material B-114 (1.0 eq, CAS No.: 185112-61-2) were dissolved in toluene solution, and sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added. The mixture was stirred evenly, heated to 110℃, and refluxed for 6 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, and the organic phase was retained. Then, the aqueous phase was extracted with ethyl acetate. After combining the organic phases, the mixture was dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator. The mixture was then dissolved in petroleum ether / ethanol for recrystallization, filtered, and the filter cake was washed multiple times with petroleum ether. The mixture was then dried in a 60℃ oven for 5 h to obtain intermediate 1 (yield: 82.3%).

[0068] Step 2 specifically includes the following steps:

[0069] Under nitrogen protection, raw material C-114 (2.0 eq, CAS No.: 750573-26-3) and intermediate 1 (1.0 eq) were dissolved in toluene solution. Sodium tert-butoxide (2.00 eq), tris(dibenzylacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added, stirred until homogeneous, heated to 120 °C, and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. The filtrate was cooled to room temperature, washed three times with water, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. The organic phases were combined, dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was washed multiple times with petroleum ether and dried in a 60 °C oven for 5 h to obtain intermediate 2 (yield: 88.4%).

[0070] Step 3 specifically includes the following steps:

[0071] Under nitrogen protection, intermediate 2 (1.0 eq) was dissolved in 1,2-dichlorobenzene, and boron triiodide (1.5 eq) was added. The mixture was stirred until homogeneous, heated to 150 °C, and refluxed for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and diisopropylamine (5.0 eq) was added to the reaction mixture. After stirring for 1 h, excess petroleum ether was added, and stirring was continued for 12 h. A solid precipitated and was filtered. The collected solid was dried in a 60 °C oven for 5 h. The remaining substance was then purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 2:10) to obtain compound 114 (yield: 26.1%, MS (ESI, m / Z): [M+H)). + =1139.59).

[0072] The obtained compound 114 was analyzed, and the results are as follows:

[0073] The proton NMR spectrum of compound 114 is shown below. Figure 1 As shown.

[0074] HPLC purity: >99.95%.

[0075] Elemental analysis:

[0076] The test values ​​are: C, 81.85; H, 4.16; B, 1.02; N, 6.26; F, 6.84.

[0077] The synthesis methods for other compounds are the same as those in the above embodiments, and will not be described in detail here. The present invention also provides an organic electroluminescent device, which is made of the organic light-emitting material, more specifically, an organic light-emitting material of a compound with chemical formula I.

[0078] Device Example 1: Fabrication of an organic electroluminescent device containing compound 114, specifically including the following steps:

[0079] a. ITO Anode: An 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 with distilled water, ultrasonically washed for 10 minutes. After washing, it is transferred to a spin dryer for drying, and finally baked in a vacuum oven at 220℃ for 2 hours. After baking, it is cooled before use. Using this substrate as the anode, a vapor deposition process is performed to deposit other functional layers sequentially on it.

[0080] b. HIL (Hole Injection Layer): with 1 Vacuum evaporation rate of / s, vacuum evaporation of hole injection layer materials HT-1 and P-dopant, wherein the evaporation rate ratio of HT-1 and P-dopant is 98:2, and the thickness is 10nm.

[0081] c. HTL (Hole Transport Layer): (The last part is incomplete and likely refers to a specific layer or structure.) At a deposition rate of / s, HT-1 of 130nm was vacuum-deposited on the hole injection layer as a hole transport layer.

[0082] d. Light-emitting auxiliary layer: with a concentration of 0.5 At a deposition rate of / s, 10nm EBL-1 was vacuum-deposited on the hole transport layer as a light-emitting auxiliary layer.

[0083] e. EML (Emitting Layer): Then, on the above-mentioned emitting auxiliary layer, with 1 The vapor deposition rate is / s, the host material with a vacuum vapor deposition thickness of 20nm and the compound 114 provided in Example 1 above are used as dopants as the light-emitting layer, wherein the vapor deposition rate ratio of the host to the dopant is 97:3.

[0084] f. HBL (Hole Blocking Layer): with a thickness of 0.5 At a deposition rate of / s, 5nm of HB-1 was vacuum-deposited on the light-emitting layer as a hole-blocking layer.

[0085] g. ETL (Electron Transport Layer): with 1 At a deposition rate of / s, a 30nm ET-1 layer was vacuum-deposited on top of the hole blocking layer as an electron transport layer.

[0086] h, EIL (Electron Injection Layer): with 0.5 At a evaporation rate of / s, a Yb film layer of 1.0 nm is deposited to form an electron injection layer.

[0087] i. Cathode: with 1 With a deposition rate ratio of / s, magnesium and silver were deposited at 13nm, with a deposition rate ratio of 1:9, resulting in an OLED device.

[0088] j. Optical extraction layer: with 1 At a evaporation rate of / s, a 65nm thick CPL-1 layer was vacuum-deposited on the cathode as a light extraction layer. The deposited substrate was then encapsulated. First, a UV adhesive was applied to the cleaned cover plate using a coating equipment. Then, the coated cover plate was moved to the lamination section, and the evaporated substrate was placed on top of the cover plate. Finally, the substrate and cover plate were laminated using a bonding equipment, while simultaneously curing the UV adhesive under UV light.

[0089] The required material structure is shown below:

[0090]

[0091] Device Examples 2-69 follow the same method as described above, but replace compound 114 used in Device Example 1 with compounds 2, 7, 10, 15, 23, 25, 29, 31, 32, 33, 43, 50, 51, 56, 60, 62, 64, 70, 71, 77, 83, 89, 97, 105, 109, 111, 112, 115, 117, 120, 127, 130, 134, and 136, respectively. Organic electroluminescent devices were prepared by using 140, 147, 156, 159, 164, 169, 174, 180, 185, 191, 195, 200, 204, 207, 211, 213, 215, 217, 220, 223, 226, 232, 237, 241, 247, 252, 258, 264, 267, 274, 280, 283, 285, and 286 as doping materials.

[0092] Comparative Example 1: This comparative example provides an organic electroluminescent device. The only difference between this organic electroluminescent device and Device Example 1 is that the organic electroluminescent device is prepared by evaporation using existing comparative compounds a, b, c, and d instead of the doping materials in Device Example 1. Comparative Examples 1 to 4 are prepared accordingly. The chemical structural formulas of comparative compounds a, b, c, and d are as follows:

[0093] .

[0094] The driving voltage, luminous efficiency, BI value and lifetime of the organic electroluminescent devices obtained in Examples 1 to 69 and Comparative Examples 1 to 4 were characterized at a brightness of 1000 nits. The test results are shown in Table 1 below.

[0095] Table 1

[0096]

[0097]

[0098]

[0099] As shown in the table above, changing the substituents and their positions will alter the device's performance, improving its luminous efficiency and lifespan to varying degrees.

[0100] Among them, compounds 114 and 116 are parallel comparative examples with compound a. The difference between them is whether or not they contain fluorine in their molecular structure. Introducing fluorine into the molecular structure can reduce the HOMO and LUMO energy levels of organic matter, enhance the charge carrier mobility, and strengthen the electrostatic forces between molecules, making the material more stable, effectively increasing the luminous efficiency, and greatly improving the device lifespan.

[0101] Compounds a and c are parallel comparative examples. The difference between them is that the parent core lacks a carbazole. Introducing aromatic amines or carbazole into the parent core increases the packing density and steric hindrance of the compound due to an excess of phenyl groups, affecting the deposition temperature and thus reducing luminous efficiency and lifetime. Carbazole, due to its strong conjugation properties, can improve intermolecular stacking and increase the degree of horizontal alignment of molecules, resulting in effective horizontal alignment and thus significantly increasing luminous efficiency and device lifetime.

[0102] Compared with organic electroluminescent devices prepared using comparative compounds a~d as doping materials, the organic electroluminescent devices prepared using the compounds provided in this invention as doping materials in the light-emitting layer have improved driving voltage, increased luminous efficiency, and extended device lifetime by 52-165 hours.

[0103] The applicant declares that this invention illustrates the polycyclic aromatic compounds and organic light-emitting devices using such compounds through the above embodiments. However, this invention is not limited to the above process steps, meaning that this invention does not necessarily rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used in this invention, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A polycyclic aromatic compound, characterized in that, The polycyclic aromatic compounds have the structure shown in Formula I-3: R3-R8 are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -SF5, hydroxyl, cyano, CF3, nitro, amino, trimethylsilyl, trimethylgermanyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, and their heteroatoms contain at least one of O, S, N, Si, Ge or Se; X3 and X4 are selected independently from... , , , , , , , , where X3 and X4 are the same or different, and * represents the linkage site of the group; in, , , or The two Rs in a At least one of them is selected from F, and the other is R. a Then it is Rc; , , , or The two Rs b At least one of them is a substituent that is not hydrogen or deuterium, and the other is R b Then it is R c ; Where R a R b and R c Each is independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermanyl, substituted or unsubstituted C1-C6 alkyl, phenyl, biphenyl or naphthyl; m can be independently selected from 0, 1, 2, 3, 4, or 5; In Formula I-3, all hydrogen atoms are either substituted with deuterium or not substituted with deuterium.

2. The polycyclic aromatic compound according to claim 1, characterized in that, R3-R8 are each independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermanium, substituted or unsubstituted C1-C6 alkyl, phenyl, biphenyl or naphthyl.

3. The polycyclic aromatic compound according to claim 1 or 2, characterized in that, The term "substitution" means substitution by a substituent selected from one or more of the following groups linked together: hydrogen, deuterium, halogen, cyano, trimethylsilyl, trimethylgermanium, trifluoromethyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, phenyl, naphthyl, anthracene, phenanthrene, thiophene, furanyl, pyrrole, benzothiophene, benzofuranyl, pyridyl, indolyl, cyclopentyl, cyclohexyl, adamantyl.

4. The polycyclic aromatic compound according to any one of claims 1-3, characterized in that, The polycyclic aromatic compounds are selected from any one of the following compounds: 。 5. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode and a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer includes a polycyclic aromatic compound as described in any one of claims 1-4.

6. The organic electroluminescent device according to claim 5, characterized in that, The organic thin film layer includes a light-emitting layer, which comprises a host material and a dopant material, wherein the dopant material comprises a polycyclic aromatic compound according to any one of claims 1-4.

7. The organic electroluminescent device according to claim 5, characterized in that, The organic thin film layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, or an electron injection layer.

Images