Polycyclic aromatic compounds and organic electroluminescent devices employing the same

Abstract

The application provides a polycyclic aromatic compound and an organic electroluminescent device adopting the compound, and belongs to the field of organic photoelectric materials.The polycyclic aromatic compound has a structure shown in formula I.The polycyclic aromatic compound provided by the application can improve the luminous efficiency of an organic electroluminescent device and prolong the service life of the device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic optoelectronic materials, and particularly relates to a polycyclic aromatic compound and an organic electroluminescent device using the compound. BACKGROUND

[0002] An organic light emitting diode (OLED) is an electroluminescent device formed by a multi-layer organic thin film structure. It has gradually entered the field of vision as a new and promising display technology due to its many advantages such as being bendable, fast response, wide viewing angle, small volume, high brightness, and bright colors. At present, OLEDs have been widely used in display devices such as smart phones, smart watches, tablet computers, and televisions, and solid-state lighting.

[0003] In the field of display and solid-state lighting, the core of OLED display technology is organic light-emitting material, which realizes full-color emission based on the mixing of red, green, and blue light materials. The development of new light-emitting materials is the driving force for the continuous progress of electroluminescent technology and a research hotspot in the organic electroluminescent industry. Many red and green light emitters have been developed and are widely used in commercial OLED products. However, there is less development of new blue organic electroluminescent materials with narrow half-peak width, high color purity, high luminous efficiency, and excellent light-emitting lifetime. Therefore, it has become a research hotspot to develop a new blue organic electroluminescent material with high luminous efficiency, long service life, narrow half-peak width, and high color purity.

[0004] At present, the construction of polycyclic aromatic compounds formed by the condensation of boron atoms and nitrogen oxygen heteroatoms with multiple aromatic rings, the use of multiple vibration effects (MR effect), and the use of boron and nitrogen oxygen heteroatoms with opposite vibrations have become the mainstream to prepare new blue organic electroluminescent materials containing special rigid material systems of boron atoms and nitrogen oxygen heteroatoms. Such fluorescent molecules have high radiation transition rate, narrow half-peak width, and high color purity, but the device lifetime and luminous efficiency are not particularly ideal. Moreover, the industrialization process of this technology still faces many key problems. Therefore, the development of new materials has always been a problem to be solved by technical personnel in the field. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a polycyclic aromatic compound and an organic electroluminescent device using the compound. The polycyclic aromatic compound provided by the present application has the advantage of improving the luminous efficiency and service life of the organic electroluminescent device.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In one aspect, the present application provides a polycyclic aromatic compound having a structure represented by Formula I:

[0008]

[0009] Y in Formula I is selected from R, , ;

[0010] R is hydrogen, deuterium, -F, -Cl, -Br, -I, -SF5, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazono, carboxylic acid group or a salt thereof, sulfonic acid group or a salt thereof, phosphoric acid group or a salt thereof, 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 heterocycloalkyl, substituted or unsubstituted C3-C10 cycloalkenyl, substituted or unsubstituted C1-C10 heterocycloalkenyl, 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 group, substituted or unsubstituted monovalent non-aromatic hetero-fused polycyclic group, Si(Q1)(Q2)(Q3), -Ge(Q1)(Q2)(Q3), -B(Q4)(Q5), -P(=O)(Q6)(Q7), or -P(Q6)(Q7);

[0011] each of Q1 to Q7 is independently hydrogen; deuterium; -F; -Cl; -Br; -I; hydroxyl; cyano; nitro; amidino; hydrazino; hydrazono; carboxylic acid group or a salt thereof; sulfonic acid group or a salt thereof; phosphoric acid group or a salt thereof; C1-C30 alkyl, C2-C30 alkenyl, C2-C30 alkynyl, C1-C30 alkoxy, C3-C10 cycloalkyl, C1-C10 heterocycloalkyl, C3-C10 cycloalkenyl, or C1-C10 heterocycloalkenyl unsubstituted or substituted with deuterium, -F, cyano, C1-C30 alkyl, C6-C30 aryl, deuterated C6-C30 aryl, fluorinated C6-C30 aryl, or any combination thereof; C6-C30 aryl, C1-C30 heteroaryl, C6-C30 aryloxy, or C6-C30 arylthio unsubstituted or 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; monovalent non-aromatic fused polycyclic group; or monovalent non-aromatic hetero-fused polycyclic group;

[0012] X1and X2are independently selected from , wherein X1and X2may be the same or different;

[0013] R1-R8are independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -SF5, hydroxyl, cyano, CF3, nitro, amino, trimethylsilyl, trimethylgermyl, substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C6-C30aryl, substituted or unsubstituted C6-C30heteroaryl, which contains at least one of O, S, N, Si, Ge or Se as a heteroatom;

[0014] X3, X4are independently selected from , , , , , , , wherein X3and X4may be the same or different, * represents the connecting site of the group;

[0015] wherein, , , or two R a in the group are selected from F, and the other R a is Rc;

[0016] , , , or two R b in the group are selected from F, and the other R b is Rc; c ;

[0017] wherein R a , R b and R c are independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermyl, substituted or unsubstituted C1-C6alkyl, phenyl, biphenyl or naphthyl;

[0018] m is independently selected from 0, 1, 2, 3, 4 or 5;

[0019] all hydrogens in formula I are independently substituted with deuterium or not substituted with deuterium.

[0020] Preferably, the polycyclic aromatic compound has the structure of a compound shown in I-1 to I-3:

[0021] .

[0022] All hydrogens in formulae 1-1 to 1-3 are independently substituted with deuterium or unsubstituted with deuterium.

[0023] Preferably, R1to R8are each independently selected from hydrogen, deuterium, fluorine, cyano, CF3, trimethylsilyl, trimethylgermyl, substituted or unsubstituted C1-C6alkyl, phenyl, biphenyl or naphthyl.

[0024] In the present application, 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 alkylthio", "substituted or unsubstituted C3-C10 cycloalkyl", "substituted or unsubstituted C1-C10 heterocycloalkyl", "substituted or unsubstituted C3-C10 cycloalkenyl", "substituted or unsubstituted C1-C10 heterocycloalkenyl", "substituted or unsubstituted C6-C60 aryl", "substituted or unsubstituted C6-C60 aryloxy", "substituted or unsubstituted C6-C60 aryloxy", "substituted or unsubstituted C6-C60 arylthio", "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 heterocycloalkyl", "substituted or unsubstituted C3-C10 cycloalkenyl", "substituted or unsubstituted C1-C10 heterocycloalkenyl", "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 C3-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 C6-C24 arylthio", "substituted or unsubstituted C1-C24 heteroaryl", "substituted or unsubstituted C1-C30 alkyl", "substituted or unsubstituted C1-C6 alkyl", "alkyl", "alkenyl", "alkynyl", "alkoxy", "alkylthio",The number of carbon atoms of cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, aryl, aryloxy, arylthio indicates the number of carbon atoms of the unsubstituted aryl group, unsubstituted alkyl group or the total number of carbon atoms constituting the heteroaryl group, without considering the number of carbon atoms in the substituents.

[0025] Preferably, said "substituted" means substituted with one or at least two substituents selected from the group consisting of hydrogen, deuterium, halogen, cyano, trimethylsilyl (TMS), trimethylgermyl, trifluoromethyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, s-butyl, 1-methylbutyl, 1-ethylbutyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, phenyl, naphthyl, anthryl, phenanthryl, thienyl, furanyl, pyrrolyl, benzothienyl, benzofuranyl, pyridyl, indolyl, cyclopentyl, cyclohexyl, adamantyl.

[0026] Preferably, said polycyclic aromatic compound is selected from any one of the following compounds:

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] .

[0039] The organic electroluminescent compound of the present application can be prepared by a synthetic method known to one skilled in the art. For example, the following reaction scheme is preferably used for the preparation.

[0040]

[0041] wherein the definitions of the groups in the above formulae are consistent with the foregoing and will not be repeated.

[0042] 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 a toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred uniformly, warmed to 90-110°C, refluxed for 4-6h; after the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove the salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is retained, then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, anhydrous magnesium sulfate is used for drying, and a rotary evaporator is used to remove the solvent, and dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake is washed with petroleum ether for multiple times, placed in a 60°C oven for drying for 5h, to obtain intermediate 1;

[0043] 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 a toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred uniformly, warmed to 90-110°C, refluxed for 4-6h; after the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove the salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is retained, then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, anhydrous magnesium sulfate is used for drying, and a rotary evaporator is used to remove the solvent, and dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake is washed with petroleum ether for multiple times, placed in a 60°C oven for drying for 5h, to obtain intermediate 2;

[0044] Step 3 specifically includes the following steps:

[0045] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred uniformly, heated to 90-120°C, and refluxed for 8-12 h; after the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove the salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is reserved, then the water phase is extracted with ethyl acetate; after the organic phases are combined, anhydrous magnesium sulfate is used for drying, and a rotary evaporator is used to remove the solvent; dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake is washed with petroleum ether for multiple times, placed in a 60°C oven for drying for 5 h, to obtain intermediate 3.

[0046] Step 4 specifically includes the following steps:

[0047] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred uniformly, heated to 90-120°C, and refluxed for 8-12 h; after the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove the salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is reserved, then the water phase is extracted with ethyl acetate; after the organic phases are combined, anhydrous magnesium sulfate is used for drying, and a rotary evaporator is used to remove the solvent; dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake is washed with petroleum ether for multiple times, placed in a 60°C oven for drying for 5 h, to obtain intermediate 4.

[0048] Step 5 specifically includes the following steps:

[0049] Under nitrogen protection, intermediate 4 (1.0 eq) is dissolved in 1,2-dichlorobenzene, boron triiodide (1.5-1.6 eq) is added, stirred uniformly, heated to 130-150°C, and refluxed for 24 h; after the reaction is completed, the temperature is lowered to room temperature, diisopropylamine (5.0 eq) is added to the reaction mixture, continues to stir for 1-2 h, then excess petroleum ether is added, continues to stir for 12-14 h, solid is precipitated, and is filtered. The collected solid is placed in a 60°C oven for drying for 5 h. The remaining material is purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain the compound of formula I.

[0050] In another aspect, the present application provides an organic electroluminescent device, which comprises an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, and the organic thin film layer comprises the polycyclic aromatic compound as described above.

[0051] Preferably, the organic thin film layer comprises a light-emitting layer, the light-emitting layer comprising a host material and a dopant material, the dopant material comprising the polycyclic aromatic compound as described above.

[0052] Preferably, the organic thin film layer further comprises 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.

[0053] Compared with the prior art, the present application has the following beneficial effects:

[0054] The polycyclic aromatic compound of the present application introduces arylamine or carbazole on the basis of the mother nucleus. Excessive phenyl groups in the compound increase the bulk density and steric hindrance of the compound, affect the evaporation temperature of the compound, and thus reduce the light-emitting efficiency and service life. The carbazole has a large conjugation property, which can improve the stacking effect between molecules and increase the horizontal arrangement degree of the molecules, so that the molecules are effectively arranged horizontally, thereby effectively increasing the light-emitting efficiency. When the arylamine groups are all substituted by aryl groups, the energy level is low, the carrier migration is localized, the hole transport energy barrier is reduced, and thus the migration rate and the light-emitting efficiency are improved. On this basis, the introduction of fluorine can reduce the HOMO and LUMO energy levels of the organic matter, enhance the charge carrier mobility, and also strengthen the electrostatic force between molecules, so that the material stability is better and the device service life is greatly improved. The device prepared by using the dopant material of the present application has significantly improved service life and efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 The nuclear magnetic resonance hydrogen spectrum of compound 114. DETAILED DESCRIPTION

[0056] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0057] In addition, it should be noted that the numerical values given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, rather than an absolutely accurate number.

[0058] The following well-known knowledge is referred to:

[0059] Transition Metals for Organic Synthesis, Robert H. Crabtree, Publisher: Shanghai East China University of Technology Press, Publication Date: 2017-09-00, ISBN: 978-7-5628-5111-0, Page 388.

[0060] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0061] Example 1

[0062]

[0063] Since there is no prior art of raw material A-114, the following synthetic route is used for synthesis:

[0064] .

[0065] Under the protection of nitrogen, 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) are added to a mixed solution of toluene, ethanol and water in a volume ratio of 2:1:1, potassium carbonate (2.2 eq) is added, tetrakis(triphenylphosphine)palladium (0.01 eq) is added, stirred uniformly, heated to 85°C, and refluxed for 4h. After the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is retained, then the aqueous phase is extracted with dichloromethane; the organic phases are combined and concentrated, a mixed solution of dichloromethane and petroleum ether is used as eluent, and column chromatography is used for purification to obtain raw material A-114 (yield: 63.7%).

[0066] Step 1 specifically includes the following steps: under the protection of nitrogen, raw material A-114 (1.4 eq) and raw material B-114 (1.0 eq, CAS No.: 185112-61-2) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq) is added, tris(dibenzylideneacetone)dipalladium (0.01 eq) is added, tri-tert-butylphosphine (0.05 eq) is added, stirred uniformly, heated to 110°C, and refluxed for 6h; after the reaction is completed, the temperature is slightly lowered, diatomite is used for filtration to remove salt and catalyst, the filtrate is cooled to room temperature, washed with water three times, the organic phase is retained, then the aqueous phase is extracted with ethyl acetate; the organic phases are combined, dried with anhydrous magnesium sulfate, and the solvent is removed using a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake is washed with petroleum ether several times, and placed in a 60°C oven for drying for 5h to obtain intermediate 1 (yield: 82.3%).

[0067] Step 2 specifically comprises the following steps:

[0068] Under nitrogen protection, raw material C-114 (2.0 eq, CAS No: 750573-26-3) and intermediate 1 (1.0 eq) were dissolved in a toluene solution, sodium tert-butoxide (2.00 eq) was added, tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) were stirred uniformly, and the reaction was refluxed at 120°C for 12 h. After the reaction was completed, the temperature was slightly lowered, diatomite was used for filtration to remove the salt and catalyst, and the filtrate was cooled to room temperature, washed with water three times, the organic phase was reserved, and then the water phase was extracted with ethyl acetate. After the organic phases were combined, anhydrous magnesium sulfate was used for drying, and a rotary evaporator was used to remove the solvent. Recrystallization was performed in petroleum ether / ethanol, the filter cake was washed with petroleum ether several times, and was placed in a 60°C oven for drying for 5 h to obtain intermediate 2 (yield: 88.4%).

[0069] Step 3 specifically comprises the following steps:

[0070] Under nitrogen protection, intermediate 2 (1.0 eq) was dissolved in 1,2-dichlorobenzene, boron triiodide (1.5 eq) was added, stirred uniformly, and the reaction was refluxed at 150°C for 24 h. After the reaction was completed, the temperature was lowered to room temperature, diisopropylamine (5.0 eq) was added to the reaction mixture, and stirring was continued for 1 h, then excess petroleum ether was added, and stirring was continued for 12 h, after which a solid was precipitated, and the solid was collected by filtration. The collected solid was placed in a 60°C oven for drying for 5 h. The remaining material was 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). +

[0071] The obtained compound 114 was subjected to detection analysis, and the results were as follows:

[0072] The nuclear magnetic resonance hydrogen spectrum of compound 114 is shown in Figure 1 .

[0073] HPLC purity: >99.95%.

[0074] Elemental analysis:

[0075] The test values were: C, 81.85; H, 4.16; B, 1.02; N, 6.26; F, 6.84.

[0076] ​The synthesis of other compounds is the same as the above examples, which are not described here. The present application also provides an organic electroluminescent device, which is made of the organic luminescent material, more specifically, the organic luminescent material of the compound of formula I.

[0077] Device Example 1: An organic electroluminescent device containing compound 114 was manufactured, specifically including the following steps:

[0078] a. ITO anode: ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150 nm was cleaned in distilled water for 2 times, ultrasonic washing for 30 min, and then repeatedly cleaned in distilled water for 2 times, ultrasonic washing for 10 min. After washing, it was transferred to a spin dryer for spin-drying, and finally baked in a vacuum oven at 220℃ for 2 hours. After baking, it was cooled and ready for use. The substrate was used as an anode, and a device process was performed using an evaporation machine. Other functional layers were sequentially evaporated thereon.

[0079] b. HIL (hole injection layer): HT-1 and P-dopant were vacuum evaporated at a deposition rate of 1 Å / s, with a thickness of 10 nm. The deposition rate ratio of HT-1 and P-dopant was 98:2.

[0080] c. HTL (hole transport layer): HT-1 was vacuum evaporated on the hole injection layer at a deposition rate of 1 Å / s, with a thickness of 130 nm, as a hole transport layer.

[0081] d. Light-emitting auxiliary layer: EBL-1 was vacuum evaporated on the hole transport layer at a deposition rate of 0.5 Å / s, with a thickness of 10 nm, as a light-emitting auxiliary layer.

[0082] e. EML (emitting layer): Then, the host material (Host) with a thickness of 20 nm and compound 114 provided in Example 1 above as a dopant material (Dopant) were vacuum evaporated on the light-emitting auxiliary layer at a deposition rate of 1 Å / s, as an emitting layer. The deposition rate ratio of Host and Dopant was 97:3.

[0083] f. HBL (hole blocking layer): HB-1 was vacuum evaporated on the emitting layer at a deposition rate of 0.5 Å / s, with a thickness of 5 nm, as a hole blocking layer.

[0084] g. ETL (electron transport layer): ET-1 was vacuum evaporated on the hole blocking layer at a deposition rate of 1 Å / s, with a thickness of 30 nm, as an electron transport layer.

[0085] h. EIL (electron injection layer): Yb film layer was evaporated at a deposition rate of 0.5 Å / s, with a thickness of 1.0 nm, to form an electron injection layer.

[0086] i. Cathode: Mg and Ag were deposited at a rate of 1 A / s with a rate ratio of 1:9 to a thickness of 13 nm, to give an OLED device.

[0087] j. Light extraction layer: CPL-1 was vacuum deposited on the cathode as a light extraction layer to a thickness of 65 nm at a rate of 1 A / s. The substrate after deposition was then encapsulated. First, the cleaned cover plate was coated with UV glue using a glue coating device, then the coated cover plate was moved to the pressing section, the substrate after deposition was placed on the end of the cover plate, and finally the substrate and cover plate were bonded under the action of the bonding device, and the UV glue was simultaneously cured by light.

[0088] The required material structures are as follows:

[0089]

[0090] Device Example 2-Device Example 69: Referring to the above method, the compound 114 used in Device Example 1 was replaced 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, 136, 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, respectively, as a doping material, to prepare the corresponding organic electroluminescent devices.

[0091] Device Comparative Example 1: This comparative example provides an organic electroluminescent device, the only difference between the preparation method of the organic electroluminescent device and Device Example 1 is that the organic electroluminescent device is deposited by replacing the doping material in the above Device Example 1 with existing comparative compounds a, b, c, d, respectively, to prepare Device Comparative Examples 1-4. The chemical structures of comparative compounds a, b, c, d are as follows:

[0092] .

[0093] The driving voltage, luminous efficiency, BI value, and lifetime of the organic electroluminescent devices obtained from Device Examples 1-69 and Device Comparative Examples 1-4 were characterized at a brightness of 1000 (nits), and the test results are shown in Table 1 below.

[0094] Table 1

[0095]

[0096]

[0097]

[0098] According to the above table, by changing the substituents and the positions of the substituents, the performance of the device will change, and the luminous efficiency and the service life of the device will be improved to different degrees.

[0099] Among them, compound 114, compound 116 and compound a are parallel examples, the difference between them is whether there is fluorine in the molecular structure, the introduction of fluorine in the molecular structure can reduce the HOMO and LUMO energy level of the organic matter, enhance the charge carrier mobility, and also can strengthen the intermolecular electrostatic force, so that the material stability is better, the luminous efficiency is effectively increased, and the device service life is greatly improved.

[0100] Compound a and compound c are parallel examples, the difference between them is that the parent nucleus lacks a carbazole, and the introduction of arylamine or carbazole on the basis of the parent nucleus, too many phenyl groups in the compound will lead to the increase of the bulk density and steric hindrance of the compound, which will affect the evaporation temperature of the compound, thereby reducing the luminous efficiency and the service life. Because carbazole has a large conjugation property, on the one hand, it can improve the stacking effect between molecules, on the other hand, it can increase the horizontal arrangement degree of molecules, so that the molecules are effectively arranged horizontally, thereby effectively increasing the luminous efficiency and the service life of the device.

[0101] The organic electroluminescent device prepared by using the compound provided by the application as a doping material in the light-emitting layer has improved driving voltage, increased luminous efficiency, and improved device service life by 52-165h compared with the organic electroluminescent device prepared by using the comparative compounds a-d as doping materials.

[0102] The applicant declares that the polycyclic aromatic compound and the organic light-emitting device using the compound of the application are illustrated by the above examples, but the application is not limited to the above process steps, that is, it does not mean that the application must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvement of the application, equivalent replacement of the raw materials selected by the application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the protection scope and disclosure scope of the application.

Claims

1. A polycyclic aromatic compound, characterized by, The polycyclic aromatic compound is selected from any one of the following compounds:

2. An organic electroluminescent device, characterized by The organic electroluminescence device includes an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, and the organic thin film layer includes the polycyclic aromatic compound of claim 1.

3. The organic electroluminescent device according to claim 2, characterized in that The organic thin film layer includes an emission layer, and the emission layer includes a host material and a dopant material, and the dopant material includes the polycyclic aromatic compound of claim 1.

4. The organic electroluminescent device according to claim 2, wherein The organic thin film layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, an electron transport layer, or an electron injection layer.

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