Polycyclic aromatic compound and organic light-emitting device adopting same

Abstract

The invention provides a polycyclic aromatic compound and an organic light-emitting device adopting the compound, and the polycyclic aromatic compound has a structure as shown in a general formula I. The polycyclic aromatic compound with the novel structure has the advantages that after the polycyclic aromatic compound is applied to the organic light-emitting device, the efficiency of the device is improved, and the organic light-emitting device has a wide application prospect. The service life is prolonged.

Description

Technical Field

[0001] The invention belongs to the field of organic photoelectric materials, and in particular relates to a polycyclic aromatic compound and an organic light-emitting device using the compound. Background Art

[0002] Organic Light Emitting Diode (OLED) is a new and promising display technology that has gradually entered people's field of vision. OLED is an electroluminescent device formed by a multi-layer organic thin film structure.

[0003] The core organic light-emitting material of OLED display technology realizes the full color range based on the mixture of red light material, green light material and blue light material. The development of new light-emitting materials is the driving force for the continuous advancement of electroluminescent technology and is also a research hotspot in the organic electroluminescent industry. The development of new blue light organic electroluminescent materials achieves high luminous efficiency and better service life of the device. At the same time, blue light-emitting materials with narrow half-width and high color purity are the focus of the development of blue light-emitting materials.

[0004] At present, the multiple vibration effect (MR effect) is used to utilize the opposite vibrations of boron and heteroatoms such as nitrogen and oxygen to construct polycyclic aromatic compounds formed by condensing multiple aromatic rings with boron atoms and heteroatoms such as nitrogen and oxygen, that is, to prepare a special rigid material system containing boron atoms and heteroatoms such as nitrogen and oxygen. This type of fluorescent molecule has a high radiation transition rate, a narrow half-peak width, and high color purity, but the performance in device life and luminous efficiency is not particularly ideal, and the industrialization process of this technology still faces many key problems. Therefore, the development of new materials has always been a problem that technicians in this field need to solve. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a polycyclic aromatic compound and an organic light-emitting device using the same. The polycyclic aromatic compound with a novel structure provided by the present invention has the advantage that after being used in an organic electroluminescent device, the efficiency of the device is improved and the service life is increased.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a polycyclic aromatic compound having a structure shown in Formula I:

[0008]

[0009] In formula I, R1-R4 are unsubstituted or substituted C1-C30 alkyl groups or hydrogen atoms;

[0010] L is selected from a linking bond, an unsubstituted C1-C30 alkyl group or a C6-C30 aryl group;

[0011] X1 is selected from O or S;

[0012] X2 is selected from O, S, NR6, CR7R8, and R6-R8 is selected from unsubstituted C1-C30 alkyl or C6-C30 aryl;

[0013] Y1-Y5 are selected from CR9, and R9 is selected from hydrogen, deuterium, unsubstituted or substituted C1-C30 alkyl, or unsubstituted or substituted C6-C30 aryl.

[0014] All hydrogens in Formula I are independently substituted with deuterium or not.

[0015] In the present invention, the C1-C30 represents that the number of carbon atoms of the defined group can be any integer from 1 to 30, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 22, 25, 28 or 30, and the C6-C30 represents that the number of carbon atoms of the defined group can be any integer from 6 to 30, for example, 6, 7, 8, 9, 10, 12, 15, 18, 20, 22, 25, 28 or 30.

[0016] Preferably, R1-R5 are independently selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl or The wavy lines represent the attachment sites of the groups.

[0017] Preferably, X2 is selected from O, S, The wavy lines represent the attachment sites of the groups.

[0018] Preferably, L is selected from a single bond, methyl, ethyl, phenyl, biphenyl or naphthyl.

[0019] The "substitution" may be mono-substitution or poly-substitution, and the substituents are selected from deuterium, C1-C30 alkyl, and C6-C30 aryl.

[0020] Preferably, the polycyclic aromatic compound is selected from any one of the following compounds:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] The organic electroluminescent compound of the present invention can be prepared by a synthetic method known to those skilled in the art. For example, it is preferably prepared by the following reaction scheme.

[0032]

[0033] wherein Hal1-Hal5 is selected from halogen (eg, F, Cl, Br or I).

[0034] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering, salt and catalyst are removed, the filtrate is cooled to room temperature, washed three times with water, the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 1;

[0035] Step 2 specifically includes the following steps: under nitrogen protection, dissolving raw material C (1.0 eq) and raw material D (1.0 eq) in a toluene solution, adding sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq), stirring evenly, heating to 110° C., and reflux reaction for 6 hours; after the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature, washed three times with water, and the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 2;

[0036] Step 3 specifically includes the following steps:

[0037] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 hours; after the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and then the aqueous phase was extracted with ethyl acetate; after the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator; dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake was rinsed with petroleum ether several times, and dried in a 60°C oven for 7 hours to obtain intermediate 3.

[0038] Step 4 specifically includes the following steps:

[0039] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours; after the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst, and the filtrate was cooled to room temperature, and the solvent was removed by a rotary evaporator; the remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0040] Step 5 specifically includes the following steps:

[0041] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 ° C. After the addition was completed, the temperature was slowly raised to 65 ° C, and stirring was continued for 3 h. Then the temperature was lowered to -30 ° C, and boron tribromide (5.0 eq) was added dropwise. After the temperature was raised to room temperature and stirring was continued for 1 h, N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 ° C and the reaction was continued for 4 h. After monitoring the reaction, the reaction was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain Formula I.

[0042] In another aspect, the present invention provides an organic electroluminescent device, comprising an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer comprises the polycyclic aromatic compound as described above.

[0043] Preferably, the organic thin film layer comprises a light-emitting layer, the light-emitting layer comprises a host material and a doping material, and the doping material comprises the polycyclic aromatic compound as described above.

[0044] 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.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The polycyclic aromatic compounds of the present invention introduce diarylamine groups on the basis of the parent core, providing a highly conjugated electron distribution system of the polycyclic aromatic compounds, allowing the molecules to be stacked effectively and orderly, thereby achieving optimal carrier transport and migration under a certain electric field. At the same time, some rigid molecular groups with high stereo hindrance are synthesized in the molecular structure, and the molecules combine long-range interactions and delocalization in a rather unique way, causing the effect of short-range high radiation attenuation rate. The charge density reorganization can minimize the singlet-triplet gap, and the device life and efficiency prepared by using the doping material of the present invention are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is the H NMR spectrum of compound 1. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0049] Example 1

[0050]

[0051] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering, salt and catalyst are removed, the filtrate is cooled to room temperature, washed three times with water, the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 1;

[0052] Step 2 specifically includes the following steps: under nitrogen protection, dissolving raw material C (1.0 eq) and raw material D (1.0 eq) in a toluene solution, adding sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq), stirring evenly, heating to 110° C., and reflux reaction for 6 hours; after the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature, washed three times with water, and the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 2;

[0053] Step 3 specifically includes the following steps:

[0054] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 hours; after the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and then the aqueous phase was extracted with ethyl acetate; after the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator; dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake was rinsed with petroleum ether several times, and dried in a 60°C oven for 7 hours to obtain intermediate 3.

[0055] Step 4 specifically includes the following steps:

[0056] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours; after the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst, and the filtrate was cooled to room temperature, and a rotary evaporator was used to remove the solvent; the remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0057] Step 5 specifically includes the following steps:

[0058] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 ° C. After the addition was completed, the temperature was slowly raised to 65 ° C, and stirring was continued for 3 h, then the temperature was lowered to -30 ° C, and boron tribromide (5.0 eq) was added dropwise, and the temperature was raised to room temperature. After stirring for 1 h, N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 ° C and the reaction was continued for 4 h. After monitoring the reaction, it was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain compound 1. (Yield: 36.1%, Mw: 1089.62).

[0059] The obtained compound 1 was tested and analyzed, and the results were as follows:

[0060] The H NMR spectrum of compound 1 is shown in Figure 1 shown.

[0061] HPLC purity: >99.95%.

[0062] Mass spectrometry test: theoretical value is 1089.58; tested value is 1089.62.

[0063] Elemental Analysis:

[0064] Calculated values ​​are: C, 83.72; H, 7.03; B, 0.99; N, 3.85; O, 1.47; S, 2.94.

[0065] The test values ​​are: C, 83.72; H, 7.58; B, 1.15; N, 3.98; O, 1.67; S, 3.10.

[0066] Example 2

[0067]

[0068] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering, salt and catalyst are removed, the filtrate is cooled to room temperature, washed three times with water, the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 1;

[0069] Step 2 specifically includes the following steps: under nitrogen protection, dissolving raw material C (1.0 eq) and raw material D (1.0 eq) in a toluene solution, adding sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq), stirring evenly, heating to 110° C., and reflux reaction for 6 hours; after the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature, washed three times with water, and the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60° C. oven for drying for 5 hours to obtain intermediate 2;

[0070] Step 3 specifically includes the following steps:

[0071] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 hours; after the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and then the aqueous phase was extracted with ethyl acetate; after the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator; dissolved in petroleum ether / ethanol, recrystallized, filtered, the filter cake was rinsed with petroleum ether several times, and dried in a 60°C oven for 7 hours to obtain intermediate 3.

[0072] Step 4 specifically includes the following steps:

[0073] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours; after the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst, and the filtrate was cooled to room temperature, and a rotary evaporator was used to remove the solvent; the remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0074] Step 5 specifically includes the following steps:

[0075] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 ° C. After the addition was completed, the temperature was slowly raised to 65 ° C, and stirring was continued for 3 h, then the temperature was lowered to -30 ° C, and boron tribromide (5.0 eq) was added dropwise, and the temperature was raised to room temperature. After stirring for 1 h, N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 ° C and the reaction was continued for 4 h. After monitoring the reaction, it was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain compound 2. (Yield: 35.4%, Mw: 1033.73).

[0076] The obtained compound 2 was tested and analyzed, and the results were as follows:

[0077] HPLC purity: >99.95%.

[0078] Mass spectrometry test: theoretical value is 1033.52; tested value is 1033.73.

[0079] Elemental Analysis:

[0080] Calculated values ​​are: C, 83.62; H, 6.63; B, 1.05; N, 4.06; O, 1.55; S, 3.10.

[0081] The test values ​​are: C, 83.26; H, 6.98; B, 1.23; N, 4.32; O, 1.78; S, 3.26.

[0082] The synthesis methods of other compounds are the same as those in the above examples, which are not described one by one here. The mass spectra, molecular formulas and yields of other synthesis examples are shown in Table 1 below:

[0083] Table 1 Mass Spectrometry Analysis and Yield of Examples

[0084] Example Compound Molecular formula MS (ESI, m / Z) Example 3 Compound 3 C75H74BN3S 1059.64 Example 4 Compound 8 C75H74BN3S 1059.58 Example 5 Compound 12 C74H72BN3OS 1061.74 Example 6 Compound 14 C71H61D5BN3OS 1024.72 Example 7 Compound 18 C78H72BN3OS 1109.79 Example 8 Compound 21 C69H57D5BN3OS 996.78 Example 9 Compound 23 C72H68BN3S2 1049.62 Example 10 Compound 26 C76H76BN3S2 1105.70 Embodiment 11 Compound 29 C71H61D5BN3S2 1040.80 Example 12 Compound 32 C78H72BN3S2 1125.68 Embodiment 13 Compound 36 C69H57D5BN3S2 1012.67 Embodiment 14 Compound 42 C80H77BN4S 1136.84 Embodiment 15 Compound 45 C74H60D5BN4S 1057.78 Example 16 Compound 54 C75H74BN3S 1099.89 Embodiment 17 Compound 60 C68H55D5BN3O2 966.73 Embodiment 18 Compound 63 C78H72BN3O2 1093.69 Embodiment 19 Compound 69 C84H76BN3OS 1185.75 Embodiment 20 Compound 76 C76H76BN3OS 1089.71 Embodiment 21 Compound 80 C75H66BN3OS 1067.69 Embodiment 22 Compound 86 C82H81BN4O 1148.82 Embodiment 23 Compound 93 C84H77BN4O 1168.78 Embodiment 24 Compound 102 C75H62D5BN4S 1071.69 Embodiment 25 Compound 105 C75H74BN3S 1059.69 Embodiment 26 Compound 113 C75H74BN3S 1059.72 Embodiment 27 Compound 115 C72H63D5BN3OS 1038.77 Embodiment 28 Compound 123 C69H57D5BN3OS 996.71 Embodiment 29 Compound 132 C68H55D5BN3S2 998.65

[0085] Device Example 1: Manufacturing an organic electroluminescent device containing Compound 1, specifically comprising the following steps:

[0086] a. ITO anode: Wash the ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150nm in distilled water twice, ultrasonically wash for 30 minutes, and then repeatedly wash it with distilled water twice, ultrasonically wash for 10 minutes. After washing, transfer it to a spin dryer for drying, and finally bake it in a vacuum oven at 220℃ for 2 hours. After baking, cool it down and it can be used. Use this substrate as the anode, use an evaporation machine to carry out the evaporation device process, and evaporate other functional layers on it in sequence.

[0087] b. HIL (hole injection layer): The hole injection layer materials HT-1 and P-dopant are vacuum-deposited at a deposition rate of 97:3, and the thickness is 10 nm;

[0088] c. HTL (hole transport layer): At a deposition rate of 100%, 130 nm of HT-1 was vacuum-deposited on the hole injection layer as a hole transport layer.

[0089] d. Light-emitting auxiliary layer: At a deposition rate of 10 nm, 10 nm EBL-1 was vacuum-deposited on the hole transport layer as a light-emitting auxiliary layer;

[0090] e. EML (light-emitting layer): Then on the above-mentioned light-emitting auxiliary layer, The host material (Host) with a thickness of 20 nm and the compound 1 provided in the above embodiment as the doping material (Dopant) are vacuum evaporated as the light-emitting layer, wherein the evaporation rate ratio of Host to Dopant is 98:2.

[0091] f. HBL (hole blocking layer): At a deposition rate of , 5 nm of HB-1 was vacuum-deposited on the light-emitting layer as a hole blocking layer;

[0092] g. ETL (Electron Transport Layer): At a deposition rate of , 30 nm of ET-1 was vacuum-deposited on the hole blocking layer as an electron transport layer;

[0093] h. EIL (electron injection layer): The evaporation rate is 1.0 nm, and a Yb film layer is evaporated to form an electron injection layer;

[0094] i. Cathode: 18 nm of magnesium and silver were evaporated at a deposition rate ratio of 1:9 to obtain an OLED device;

[0095] j. Light extraction layer: The evaporation rate is 70nm, and CPL-1 with a thickness of 70nm is vacuum evaporated on the cathode as a light extraction layer. The evaporated substrate is then packaged. First, the cleaned cover is coated with UV glue using a glue coating device, and then the coated cover is moved to the pressing section, and the evaporated substrate is placed on the upper end of the cover. Finally, the substrate and the cover are bonded by the bonding equipment, and the UV glue is cured by light.

[0096] The required material structure is as follows:

[0097]

[0098] Device Example 2-Device Example 29 refers to the above method, and the compound 1 used in device example 1 is replaced by compounds 2, 3, 8, 12, 14, 18, 21, 23, 26, 29, 32, 36, 42, 45, 54, 60, 63, 69, 76, 80, 86, 93, 102, 105, 113, 115, 123, and 132 as doping materials to prepare corresponding organic electroluminescent devices.

[0099] 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 the device embodiment 1 is that the organic electroluminescent device uses existing comparative compounds a, b, c, and d to replace the doping materials in the above device embodiment 1 for evaporation to prepare device comparative examples 1 to 4. Among them, the chemical structural formulas of comparative compounds a, b, c, and d are as follows:

[0100]

[0101] The driving voltage, luminous efficiency, BI value and lifespan of the organic electroluminescent devices obtained from the above device embodiments 1 to 29 and device comparative examples 1 to 4 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2 below.

[0102] Table 2

[0103]

[0104] According to the above table, the organic electroluminescent device prepared by using the compound provided by the present invention as the doping material in the light-emitting layer has improved driving voltage, luminous efficiency and life compared with the organic electroluminescent device prepared by using comparative compounds 1 to 4 as the doping material.

[0105] The applicant declares that the present invention illustrates the compounds and applications of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polycyclic aromatic compound, characterized in that: The polycyclic aromatic compound has a structure shown in the general formula I: In formula I, R1-R4 are unsubstituted or substituted C1-C30 alkyl groups or hydrogen atoms; L is selected from a linking bond, an unsubstituted C1-C30 alkyl group or a C6-C30 aryl group; X1 is selected from O or S; X2 is selected from O, S, NR6, CR7R8, and R6-R8 is selected from unsubstituted C1-C30 alkyl or C6-C30 aryl; Y1-Y5 are selected from CR9, and R9 is selected from hydrogen, deuterium, unsubstituted or substituted C1-C30 alkyl, or unsubstituted or unsubstituted C6-C30 aryl.

2. The polycyclic aromatic compound according to claim 1, characterized in that All hydrogens in Formula I are independently substituted with deuterium or not.

3. The polycyclic aromatic compound according to claim 1, characterized in that: R1-R4 are independently selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl or The wavy lines represent the attachment sites of the groups.

4. The polycyclic aromatic compound according to claim 1, characterized in that: X2 is selected from O, S, The wavy lines represent the attachment sites of the groups.

5. The polycyclic aromatic compound according to claim 1, characterized in that: L is selected from a single bond, methyl, ethyl, phenyl, biphenyl or naphthyl.

6. The polycyclic aromatic compound according to any one of claims 1 to 5, characterized in that: The polycyclic aromatic compound is selected from any one of the following compounds:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer comprises the polycyclic aromatic compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic thin film layer includes a light-emitting layer, the light-emitting layer includes a host material and a doping material, and the doping material includes the polycyclic aromatic compound according to any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 7 or 8, 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