Organic electroluminescent material, organic electroluminescent device and application

Abstract

The invention discloses an organic electroluminescent material and an organic electroluminescent device and application thereof.The organic electroluminescent material can serve as a functional layer of the organic electroluminescent device, 9-alkyl-9-phenyl-9H-fluorene serves as a parent nucleus and is directly connected with arylamine on the parent nucleus, one side chain of the arylamine is aryl or heteroaryl, the other side chain of the arylamine is 1, 1, 4, 5, 6-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1, 3-tetramethyl-1 Compared with other compounds, the organic electroluminescent material compound disclosed by the invention has the advantages that the transverse electric leakage is small, and the phenomena that adjacent pixels are lightened, transverse crosstalk is generated between adjacent sub-pixels and color display is influenced due to transverse leakage current of the adjacent pixels in a device can be reduced. The organic electroluminescent material is used as a functional layer of the organic electroluminescent device, and the problems that color display is affected and picture display is abnormal due to transverse electric leakage of an OLED display device can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic materials. Specifically, it particularly relates to an organic electroluminescent material, an organic electroluminescent device, and an application thereof. Background Art

[0002] After entering the 21st century, with the rapid development of technology and the continuous improvement of people's living standards, traditional flat panel displays have been difficult to meet people's diverse needs for future life, and there is an urgent need for a new generation of flat panel displays with more excellent performance. Among many emerging display technologies, display devices made of organic light-emitting diodes (OLEDs) stand out. OLED display technology is based on the electroluminescence principle of organic materials. Under the action of an electric field, holes and electrons in the organic material recombine and release energy, thereby exciting photons to achieve light emission. This unique light-emitting mechanism endows OLED display devices with many incomparable advantages. It has the characteristic of a small volume, which enables electronic devices to be designed to be more lightweight and compact; the wide viewing angle greatly improves the viewing comfort and convenience. Based on these outstanding advantages, OLED display devices have shown extremely broad application prospects in many display fields such as smart phones, tablet computers, televisions, and wearable devices.

[0003] Generally speaking, the basic structure of an OLED display device includes a substrate and red (R) light-emitting pixels, green (G) light-emitting pixels, and blue (B) light-emitting pixels disposed on the substrate. In order to effectively control and drive the pixels, these three types of light-emitting pixels usually form a common layer in a series connection manner. However, there is a problem that cannot be ignored in the design of this common layer. Since the common layer is continuously penetrated throughout the surface, when the device is powered on and working, during the hole transport process, the current that should theoretically be transmitted longitudinally will have a lateral leakage current phenomenon due to the mutual influence between pixels, that is, there is a situation of lateral conduction. In this case, the current will be transmitted from the current sub-pixel to the adjacent sub-pixel, thereby causing the adjacent pixel to be accidentally lit and generating lateral crosstalk between adjacent sub-pixels.

[0004] This horizontal crosstalk problem has a serious negative impact on the display effect. For example, when a green pixel is adjacent to a red pixel, green light is mixed into the red pixel, making the red light originally emitted by the red pixel impure. Especially in the low gray level state, the brightness deviation caused by this horizontal crosstalk current in the sub-pixels becomes extremely significant. This phenomenon directly leads to the inability to accurately adjust the white light of the display panel within the specified specification range in the white screen color coordinates, and then causes a series of serious problems such as a reduction in the color gamut of the screen, color shift, and abnormal display of the screen, greatly reducing the display quality and affecting the user's visual experience. Therefore, how to effectively reduce the horizontal leakage phenomenon of OLED display devices has become an urgent problem to be solved in the current OLED display technology field. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides an organic electroluminescent material, an organic electroluminescent device and an application thereof. This organic electroluminescent material can be used as a functional layer of the organic electroluminescent device. With 9-alkyl-9-phenyl-9H-fluorene as the parent nucleus, an arylamine is directly connected to the parent nucleus. One side chain of the arylamine is an aryl group or a heteroaryl group, and the other side chain is a 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene derivative. Compared with other compounds, the organic electroluminescent material compound of the present invention has small horizontal leakage, can reduce the occurrence of horizontal leakage current between adjacent pixels in the device, resulting in adjacent pixels being lit, and horizontal crosstalk occurring between adjacent sub-pixels, affecting the color display. As a functional layer of the organic electroluminescent device, the organic electroluminescent material of the present invention can solve problems such as affecting color display and abnormal display of the screen due to horizontal leakage of OLED display devices.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In the first aspect of the present invention, an organic electroluminescent material is provided, having a compound structure shown in General Formula I:

[0008] ;

[0009] Wherein, Ar 1 independently selected from substituted or unsubstituted C 6 -C 18 aryl, substituted or unsubstituted C 6 -C 18 heteroaryl, the heteroatoms of which contain at least one of O, S, N, Si, Se;

[0010] Ar 2 independently selected from substituted or unsubstituted C 6 -C 15 aryl, substituted or unsubstituted C 6 -C18 A heteroaryl group, the heteroatoms of which contain at least one of O, S, and N;

[0011] L is independently selected from a single bond, a substituted or unsubstituted C 6 -C 18 aryl group, a substituted or unsubstituted C 6 -C 18 heteroaryl group, the heteroatoms of which contain at least one of O, S, N, Si, and Se;

[0012] R 1 is independently selected from C 1 -C 16 an alkyl group which is substituted or unsubstituted with deuterium;

[0013] R 2 and R 3 each independently is selected from hydrogen, deuterium, a halogen group, a cyano group, a substituted or unsubstituted C 1 -C 16 alkyl group, a substituted or unsubstituted C 6 -C 30 aryl group, a substituted or unsubstituted C 6 -C 30 heteroaryl group, the heteroatoms of which contain at least one of O, S, N, Si, and Se;

[0014] All hydrogens in Formula I can be independently substituted or unsubstituted with deuterium.

[0015] In one embodiment of the present invention, the L is independently selected from a single bond, a substituted or unsubstituted benzene, a substituted or unsubstituted biphenyl, a substituted or unsubstituted naphthalene, a substituted or unsubstituted dibenzofuran, a substituted or unsubstituted dibenzothiophene, a substituted or unsubstituted dibenzofluorene, and a substituted or unsubstituted carbazole.

[0016] In one embodiment of the present invention, R 1 is independently selected from C 1 -C 6 an alkyl group which is substituted or unsubstituted with deuterium;

[0017] R 2 and R 3 each independently is selected from hydrogen, deuterium, a halogen group, a cyano group, a substituted or unsubstituted C 1 -C 15 alkyl group, a substituted or unsubstituted C 6 -C 15 aryl group, a substituted or unsubstituted C 6 -C 15 heteroaryl group, the heteroatoms of which contain at least one of O, S, N, Si, and Se.

[0018] In one embodiment of the present invention, Ar2 Independently selected from substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted dibenzofuran.

[0019] In one embodiment of the present invention, the compound of the structure shown in Formula I has the structures in Formulae I-1 to I-8 as follows:

[0020] ;

[0021] Wherein, R 1 Independently selected from methyl substituted or unsubstituted with deuterium, ethyl substituted or unsubstituted with deuterium, propyl substituted or unsubstituted with deuterium, tert-butyl substituted or unsubstituted with deuterium;

[0022] R 2 R 3 Are each independently selected from the following substituents; hydrogen, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl, cyano, fluoro, trimethylsilyl (TMS), substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl;

[0023] R 4 Independently selected from substituted or unsubstituted benzene;

[0024] Ar 1 Independently selected from the following substituents;

[0025]

[0026]

[0027] And the hydrogen in the above groups can each independently be substituted or unsubstituted with deuterium;

[0028] * indicates the group connection position.

[0029] In one embodiment of the present invention, the terms "substituted or unsubstituted C 6 -C 18 aryl", "substituted or unsubstituted C 6 -C 18 heteroaryl", "substituted or unsubstituted C 1 -C 15 alkyl", "substituted or unsubstituted C 6 -C 30 aryl", "substituted or unsubstituted C 6 -C 30 heteroaryl", "substituted or unsubstituted C 1 -C 6 alkyl", "substituted or unsubstituted C 6 -C15 "aryl", "substituted or unsubstituted C" 6 -C 15 In "aryl", "heteroaryl" and "alkyl", the number of carbon atoms of aryl, heteroaryl and alkyl represents the number of carbon atoms that make up unsubstituted aryl, unsubstituted alkyl or the total number of heteroatoms and carbon atoms that make up heteroaryl, without considering the number of carbon atoms in the substituents.

[0030] The term "substituted" means being substituted by one, two or more substituents selected from the following: hydrogen, deuterium, halogen group, cyano group, trifluoromethyl group, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, sec-butyl group, 1-methylbutyl group, 1-ethylbutyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, 1-methylhexyl group, phenyl group, naphthyl group, anthracenyl group, phenanthryl group, thienyl group, furyl group, pyrrolyl group, benzothienyl group, benzofuryl group, pyridyl group, indolyl group, cyclopentyl group, cyclohexyl group, adamantane or a substituent formed by connecting two or more of the substituents shown above, or having no substituent.

[0031] In one embodiment of the present invention, the compound having the structure shown in General Formula I includes any one of the following Compounds 1-596, but is not limited thereto:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046] ;

[0047] The organic electroluminescent compounds of the present invention can be prepared by synthetic methods known to those skilled in the art.

[0048] In one embodiment of the present invention, the preparation process of the organic electroluminescent material is as follows:

[0049] Synthesis route:

[0050]

[0051] Among them, Ar in the above formula 1 ,Ar 2 ,L,R 1 , R 2 , R 3 The limitations are the same as above and will not be repeated here.

[0052] Specifically, the following steps are included:

[0053] Step 1): Under nitrogen protection, raw material A (1.3-1.4eq) and raw material B (1.0eq) are dissolved in toluene solution, sodium tert-butoxide (2.00eq), tri(dibenzylideneacetone)dipalladium (0.01eq), tri-tert-butylphosphine (0.05eq) are added, stirred evenly, heated to 90-110°C, and refluxed for 4-6h; after the reaction is completed, the temperature is slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate is cooled to room temperature and 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 several times, and placed in a 60°C oven for drying for 5h to obtain intermediate 1.

[0054] Step 2): Under a nitrogen environment, raw material C (1.0 eq) and raw material D (1.0 eq) are added to a mixed solution of toluene, ethanol and water, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) are added thereto, stirred evenly, heated to 70°C-90°C, and refluxed for 4-12 hours, and the reaction is detected by thin layer chromatography. After the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtration to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed three times with water, the organic phase is retained, and then the aqueous phase is extracted with dichloromethane; the organic phases are combined and concentrated, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and the intermediate 2 is purified by column chromatography.

[0055] Step 3): Under nitrogen protection, intermediate 2 (1eq) and intermediate 1 (1.3-1.4eq) are dissolved in toluene solution, sodium tert-butoxide (2.00eq), tri(dibenzylideneacetone)dipalladium (0.01eq), tri-tert-butylphosphine (0.05eq) are added, stirred evenly, heated to 90-110°C, and refluxed for 4-6h; after the reaction is completed, the temperature is slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate is cooled to room temperature and 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 using anhydrous magnesium sulfate, and the solvent is removed using a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether several times, and placed in a 60°C oven for drying for 5h to obtain compound formula I.

[0056] The third aspect of the present invention also provides an organic electroluminescent device, which includes an anode, a hole injection layer, a hole transport layer, a luminescence auxiliary layer, a luminescent layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode arranged in sequence; the luminescence auxiliary layer contains the organic electroluminescent material.

[0057] The fourth aspect of the present invention also provides an application of the above-mentioned organic electroluminescent material or organic electroluminescent device in smart phones, flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for internal or external lighting and / or signals, head-up displays, fully transparent or partially transparent displays, flexible displays, laser printers, telephones, tablets, photo albums, personal digital assistants, wearable devices, laptops, digital cameras, camcorders, viewfinders, microdisplays, three-dimensional displays, virtual reality or augmented reality displays, vehicles, video walls including multiple displays tiled together, theater or venue screens, light therapy devices and signs.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The organic electroluminescent material provided by the present invention can be used as a functional layer of an organic electroluminescent device. With 9-alkyl-9-phenyl-9H-fluorene as the parent nucleus, an arylamine is directly connected to the parent nucleus. One side chain of the arylamine is an aryl group or a heteroaryl group, and the other side chain is a 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene derivative. Compared with other compounds, this luminescent material has low lateral leakage current, can reduce the occurrence of lateral leakage current between adjacent pixels in the device and the phenomenon of lateral conduction, thereby avoiding the lighting of adjacent pixels in the display device, the generation of lateral crosstalk between adjacent sub-pixels, and the reduction of the color gamut, color shift, and the impact on color display of the screen. As a functional layer of an organic electroluminescent device, the organic electroluminescent material of the present invention can solve the problems of affecting color display and abnormal screen display due to lateral leakage current of OLED display devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings.

[0061] Figure 1 1H NMR spectrum of Compound 17.

[0062] Figure 2 Lateral current I-V test curves of Compounds 17, 18, 256 and Comparative Compounds 3 and 4 under 0 - 12V voltage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention and the relevant drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0064] In addition, it should be noted that the values given in the following embodiments are as accurate as possible. However, those skilled in the art understand that due to inevitable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0065] Refer to the following common general knowledge:

[0066] "Transition Metal Organometallic Chemistry" (Sixth Edition, original work), Robert H. Crabtree, Publisher: East China University of Science and Technology Press, Publication Date: 2017-09-00, ISBN: 978-7-5628-5111-0, Page 388.

[0067] "Experimental Course of Organic Chemistry and Optoelectronic Materials", Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0068] The features and properties of the present invention will be further described in detail below in combination with specific embodiments.

[0069] Example 1

[0070] Synthesis of Compound 17:

[0071] ;

[0072] The specific synthesis steps are as follows:

[0073] Step 1): Under nitrogen protection, dissolve raw material A-17 (1.3eq) and raw material B (1.0eq) in toluene solution, add sodium tert-butoxide (2.00eq), tris(dibenzylideneacetone)dipalladium(0.01eq), tritert-butylphosphine(0.05eq), stir evenly, heat up to 110 °C, and reflux for 6 h; after the reaction is completed, slightly lower the temperature, filter using diatomaceous earth to remove salts and catalysts, cool the filtrate to room temperature, wash three times with water, retain the organic phase, then extract the aqueous phase with ethyl acetate; after combining the organic phases, dry with anhydrous magnesium sulfate, remove the solvent using a rotary evaporator, dissolve in petroleum ether / ethanol, perform recrystallization, filter, wash the filter cake with petroleum ether multiple times, and place it in an oven at 60 °C to dry for 5 h to obtain Intermediate 1 (Yield: 82.4%).

[0074] Step 2): Under a nitrogen atmosphere, add raw material C-17(1.0eq) and raw material D-17(1.0eq) to a mixed solution of toluene, ethanol and water, add potassium carbonate(2.2eq), tetrakis(triphenylphosphine)palladium(0.01eq), stir evenly, heat up to 90 °C, and reflux for 8 h. Detect the reaction using thin-layer chromatography. After the reaction is completed, slightly lower the temperature, filter using diatomaceous earth to remove salts and catalysts, cool the filtrate to room temperature, wash three times with water, retain the organic phase, then extract the aqueous phase with dichloromethane; after combining the organic phases, concentrate, use a mixed solution of dichloromethane and petroleum ether as the eluent, and purify by column chromatography to obtain Intermediate 2 (Yield: 78.5%).

[0075] Step 3): Under nitrogen protection, intermediate 2 (1 eq) and intermediate 1 (1.3-1.4 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 110°C, and refluxed for 6 h; 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 using anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was rinsed with petroleum ether several times and dried in a 60°C oven for 5 h to obtain compound 17 (yield: 81.6%, MS (ESI, m / Z): [M+H]+= 725.56).

[0076] The obtained compound 17 was detected and analyzed using a Waters XEVO TQD mass spectrometer with low precision and ESI source test. The results are as follows:

[0077] The H NMR spectrum of compound 17 is shown in Figure 1 shown.

[0078] HPLC purity: >99.95%.

[0079] Elemental analysis: Test values ​​are: C, 90.91; H, 7.16; N, 2.02.

[0080] Prepare compounds 1, 2, 4, 6, 8, 9, 15, 18, 21, 22, 25, 26, 28, 33, 34, 40, 45, 47, 55, 57, 60, 69, 76, 79, 85, 88, 101, 102, 108, 110, 111, 125, 129, 130, 140, 145, 149, 157, 161, 171, 176, 185, 187, 191, 195, 203, 209, 217, 222, 242, 245, 256, 270, 272, 277, 278, 289, 294, 296, 300, 309, 311, 315, 318, 320, 323, 331, 333, 342, 344, 347, 354, 368, 370, 389, 393, 397, 402, 410, 415, 418, 422, 425, 427, 436, 440, 445, 455, 462, 467, 473, 486, 496, 500, 503, 512, 518, 528, 535, 537, 543, 547, 554, 560, 566, 574, 581, 586, 591 and 596, etc. The synthesis methods of these compounds are the same as those in Example 1 above and will not be elaborated here one by one.

[0081] For further description of the present invention, the following more specific application examples are listed

[0082] Device Preparation Example 1

[0083] Preparation of Red Organic Electroluminescent Device

[0084] The structure of the prepared OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0085] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 Å is washed 3 times in distilled water, ultrasonically washed for 40 min, then repeatedly washed 3 times with distilled water and ultrasonically washed for 20 min. After washing, it is ultrasonically washed with methanol, acetone, and isopropanol in sequence (each washing for 5 min), dried, then transferred to a plasma cleaner for washing for 5 min, and then sent to an evaporation coater. Using this substrate as the anode, other functional layers are evaporated on it in sequence.

[0086] b. HIL (hole injection layer): The hole injection layer materials HT-1 and P-dopant are vacuum-evaporated as the hole injection layer at an evaporation rate of 1 Å / s, and the evaporation rate ratio of HT-1 and P-dopant is 97:3, with a thickness of 10 nm.

[0087] c, HTL (Hole Transport Layer): At a deposition rate of 1.5 / s, vacuum deposit 125 nm of HT-1 on the hole injection layer as the hole transport layer.

[0088] d, Prime (Luminescence-Assisting Layer): At a deposition rate of 0.5 Å / s, vacuum deposit 100 nm of Compound 17 provided in the above embodiment on the hole transport layer as the luminescence-assisting layer.

[0089] e, EML (Emission Layer): At a deposition rate of 1 Å / s, vacuum deposit a total thickness of 40 nm of host materials (Host-1 and Host-2) and a dopant material (Dopant-1) on the luminescence-assisting layer as the emission layer. The deposition rate ratio of the host materials to the dopant material is 97:3, and the deposition rate ratio of Host-1 to Host-2 in the host materials is 4:6. The chemical formulas of Host-1, Host-2, and Dopant-1 are shown below.

[0090] f, HBL (Hole Blocking Layer): At a deposition rate of 0.5 Å / s, vacuum deposit a 5-nm-thick hole blocking layer HB-1 on the emission layer.

[0091] g, ETL (Electron Transport Layer): At a deposition rate of 1 Å / s, vacuum deposit 30 nm of ET-1 and Liq on the hole blocking layer as the electron transport layer, where the deposition rate ratio of ET-1 to Liq is 50:50.

[0092] h, EIL (Electron Injection Layer): At a deposition rate of 0.5 Å / s, vacuum deposit a 1-nm-thick Yb film layer on the electron transport layer to form the electron injection layer.

[0093] i, Cathode: Deposit 13 nm of magnesium and silver at a deposition rate ratio of 1 Å / s, and the deposition rate ratio is 1:9 to obtain the cathode.

[0094] j, CPL (Light Extraction Layer): At a deposition rate of 1 Å / s, vacuum deposit 60 nm of CPL-1 on the cathode as the light extraction layer.

[0095] K. Package the substrate after deposition: First, use a coating device to coat the cleaned cover plate with UV glue, then move the coated cover plate to the lamination section, place the deposited substrate on the upper end of the cover plate, and finally laminate the substrate and the cover plate under the action of a laminating device, while completing the photo-curing of the UV glue.

[0096] The structures of HT-1, P-dopant, Host-1, Host-2, Dopant-1, HB-1, ET-1, and CPL-1 used in the above Device Preparation Example 1 are shown below:

[0097]

[0098] Device Preparation Example 2 - 12

[0099] Referring to the preparation method in the above Device Preparation Example 1, compounds 18, 26, 110, 149, 187, 256, 393, 397, 427, 535, and 586 were respectively selected to replace compound 17, and the evaporation of the light-emitting auxiliary layer was carried out, and the corresponding organic electroluminescent devices were prepared, which were respectively recorded as Device Preparation Examples 2 - 12.

[0100] Device Control Examples 1 - 4

[0101] The preparation method of the organic electroluminescent device in the above Device Preparation Example 1 was the same, except that compound 17 in Device Preparation Example 1 was replaced with compounds a, b, c, d, and the structural formulas of compounds a, b, c, d are as follows:

[0102]

[0103] The driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained in the above Device Preparation Examples 1 - 12 and Device Control Examples 1 - 4 were characterized at a brightness of 6000 (nits), and the test results are shown in Table 1 below.

[0104] Table 1. Test Results of the Luminescence Characteristics of the Organic Electroluminescent Devices in Device Preparation Examples 1 - 12 and Device Control Examples 1 - 4

[0105] (Brightness value is 6000 nits)

[0106]

[0107] It can be seen from the data in Table 1 that compared with the organic electroluminescent devices provided by Device Control Examples 1 - 4, the OLED devices prepared by using the light-emitting auxiliary material provided by the present invention in Device Preparation Examples 1 - 12, the light-emitting auxiliary material provided by the present invention is better than the existing organic electroluminescent devices in terms of device lifetime, with an improvement of 2 - 5% compared with the device control examples. At the same time, there is also a certain improvement in the driving voltage and luminous efficiency of the device.

[0108] The reason is that the compound material provided by the present invention has less lateral leakage current compared with other compounds, which can reduce the probability of lateral leakage current occurring between adjacent pixels in the device, and avoid the phenomenon that adjacent pixels are lit and lateral crosstalk occurs between adjacent sub-pixels, thus affecting color display.

[0109] The following further explains the present invention by using theoretical calculation simulation and the preparation and testing of the lateral current of the comb-shaped substrate.

[0110] Theoretical calculation and simulation

[0111] The results of theoretical calculation and simulation of the x, y, and z-axis mobilities and molecular orientation parameters of the following compounds using molecular dynamics simulation software are shown in Table 2:

[0112] Among them, the x-axis mobility represents the lateral current of the compound.

[0113] Table 2

[0114]

[0115] It can be obtained from theoretical calculation that: the smaller the molecular orientation parameter, the larger the z-axis mobility, the smaller the x-axis mobility, and the smaller the lateral current.

[0116] Application Example 1

[0117] Preparation of a comb-shaped substrate and measurement of lateral current

[0118] Use an evaporation machine to perform evaporation on the comb-shaped substrate at an evaporation rate of 1 Å / s in a vacuum to evaporate Compound 17 and P-dopant. The chemical formulas are as follows. The evaporation rate ratio of Compound 17 and P-dopant is 100:3, and the thickness is 10 nm; then, evaporate Compound 17 with a thickness of 85 nm at an evaporation rate of 1.5 Å / s in a vacuum.

[0119] Chemical formula of P-dopant:

[0120] .

[0121] Application Examples 2 - 104

[0122] Prepare Application Examples 2 - 104 according to the above method for preparing the substrate, and replace Compound 17 with the corresponding compounds in Application Examples 2 - 104, as shown in Table 3 for details.

[0123] Comparative Examples 1 - 22

[0124] According to the above method for preparing the substrate, replace Formula I with the corresponding compounds respectively. The difference is that Formula I is replaced with Comparative Compounds 1 - 22. The structural formulas of Comparative Compounds 1 - 22 are as follows, namely Comparative Examples 1 - 22:

[0125]

[0126]

[0127] Use an IVL tester to perform current-voltage (IV) testing on the above-prepared substrates at room temperature. The parameter settings are a voltage of 0 - 12 V, and the test is performed with a step size of 0.1. The results are shown in Table 3:

[0128] Table 3. Lateral current test results of application examples and comparative examples under 12V voltage

[0129]

[0130]

[0131]

[0132]

[0133] Figure 2 The lateral current I-V test curves of Compound 17, Compound 18, Compound 256, Comparative Compound 3 and Comparative Compound 4 under 0-12V voltage are shown. It can be seen that the lateral currents of Compound 17 and Compound 18 are less than that of Compound 256, and far less than those of Comparative Compound 3 and Comparative Compound 4.

[0134] From the test results in Table 3 above, it can be known that the lateral leakage of the luminescent material compound provided by the present invention is much less than that of the comparative compound. Under 12V voltage, the lateral current of the luminescent material provided by the present invention is between 0.000187-0.000738mA, and the lateral current of the comparative compound is 0.00410-0.00713mA. The lateral current is reduced by 5.55-38.12 times compared with the comparative compound, which is consistent with the results shown by the theoretical calculation.

[0135] In summary, the organic electroluminescent material provided by the present invention can be used as a functional layer of an organic electroluminescent device. With 9-alkyl-9-phenyl-9H-fluorene as the parent nucleus, an arylamine is directly connected to the parent nucleus. One side chain of the arylamine is an aryl group or a heteroaryl group, and the other side chain is a 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene derivative. Compared with other compounds, the compound of the present invention has small lateral leakage, and can reduce the phenomenon that lateral leakage current occurs between adjacent pixels in the device, resulting in adjacent pixels being lit, lateral crosstalk between adjacent sub-pixels, and affecting color display.

[0136] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0137] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material, characterized in that: The organic electroluminescent material has a compound structure shown in general formula I: ； wherein Ar1 is independently selected from substituted or unsubstituted C6-C 18 Aryl, substituted or unsubstituted C6-C 18 Heteroaryl, whose heteroatom contains at least one of O, S, N, Si and Se; Ar2 is independently selected from substituted or unsubstituted C6-C 15 Aryl, substituted or unsubstituted C6-C 18 Heteroaryl, whose heteroatom contains at least one of O, S and N; L is independently selected from a single bond, a substituted or unsubstituted C6-C 18 Aryl, substituted or unsubstituted C6-C 18 Heteroaryl, whose heteroatom contains at least one of O, S, N, Si and Se; R1 is independently selected from C1-C 16 Alkyl groups which may or may not be substituted with deuterium; R2 and R3 are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C 16 Alkyl, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C6-C 30 Heteroaryl, whose heteroatom contains at least one of O, S, N, Si and Se; All hydrogens in formula I may independently be substituted with deuterium or may be unsubstituted.

2. The organic electroluminescent material according to claim 1, characterized in that: Ar2 is independently selected from substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, and substituted or unsubstituted dibenzofuran.

3. The organic electroluminescent material according to claim 1, characterized in that: R1 is independently selected from C1-C6 deuterium-substituted or unsubstituted alkyl; R2 and R3 are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C 15 Alkyl, substituted or unsubstituted C6-C 15 Aryl, substituted or unsubstituted C6-C 15 The heteroaryl group contains at least one of O, S, N, Si and Se as heteroatoms.

4. The organic electroluminescent material according to claim 1, characterized in that: The L is independently selected from a single bond, substituted or unsubstituted benzene, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthalene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted dibenzofluorene, substituted or unsubstituted carbazole.

5. The organic electroluminescent material according to claim 1, characterized in that: The compound of the structure shown in Formula I has the following structures in Formulas I-1 to I-8: ； Wherein, R1 is independently selected from methyl substituted or unsubstituted by deuterium, ethyl substituted or unsubstituted by deuterium, propyl substituted or unsubstituted by deuterium, tert-butyl substituted or unsubstituted by deuterium; R2, R3 are independently selected from the following substituents: hydrogen, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl, cyano, fluoro, trimethylsilyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl; R4 is independently selected from substituted or unsubstituted benzene; Ar1 is independently selected from the following substituent groups; ； Furthermore, the hydrogen atoms in the above mentioned groups may be independently substituted by deuterium or not; * indicates the connection position of the group.

6. The organic electroluminescent material according to any one of claims 1 to 5, characterized in that: The "substituted or unsubstituted C6-C 18 Aryl", "substituted unsubstituted C6-C 18 "heteroaryl", "substituted or unsubstituted C1-C 15 "alkyl", "substituted or unsubstituted C6-C 30 "Aryl", "substituted or unsubstituted C6-C 30 "heteroaryl", "substituted or unsubstituted C1-C6 alkyl", "substituted or unsubstituted C6-C 15 "Aryl", "substituted or unsubstituted C6-C 15 The number of carbon atoms of the aryl, heteroaryl and alkyl groups in "heteroaryl" means the number of carbon atoms constituting the unsubstituted aryl group, the unsubstituted alkyl group or the total number of heteroatoms and carbon atoms constituting the heteroaryl group, without considering the number of carbon atoms in the substituent; The term "substituted" means substituted by one, two or more substituents selected from the group consisting of hydrogen, deuterium, halogen, cyano, 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, anthracenyl, phenanthrenyl, thienyl, furanyl, pyrrolyl, benzothienyl, benzofuranyl, pyridyl, indolyl, cyclopentanyl, cyclohexanyl, adamantane, or substituted by two or more of the substituents shown above connected to each other, or having no substituent.

7. The organic electroluminescent material according to claim 1, characterized in that: The compound represented by the general formula I is selected from any one of the following compounds 1-596: 。 8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a hole injection layer, a hole transport layer, a luminescence auxiliary layer, a luminescent layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode arranged in sequence; the luminescence auxiliary layer contains the organic electroluminescent material according to any one of claims 1 to 7.

9. Use of the organic electroluminescent material according to any one of claims 1 to 7 or the organic electroluminescent device according to claim 8 in a smart phone, a computer, a television, a car screen, a wearable device, a computer monitor and a medical monitor.

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