Organic electroluminescent materials, organic electroluminescent devices and their applications

Abstract

The invention discloses a kind of organic electroluminescent material and organic electroluminescent device and application, the organic electroluminescent material can be used as the functional layer of organic electroluminescent device, with 9 alkyl 9 phenyl 9H fluorene as parent nucleus, directly connected to arylamine on parent nucleus, one of the side chains of arylamine is aryl or heteroaryl, and the other side chain is 1,1,4,4 tetramethyl 1,2,3,4 tetralin derivative, compared to other compounds, the organic electroluminescent material compound of the present invention has small lateral leakage, can reduce adjacent pixels in device and produce lateral leakage current, cause adjacent pixels to be lit, produce lateral crosstalk between adjacent sub-pixels, affect the phenomenon of color display. The organic electroluminescent material of the present invention is as the functional layer of organic electroluminescent device, can solve the problems such as color display and picture display abnormality affected by OLED display device lateral leakage.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic photoelectric materials, and in particular relates to an organic electroluminescent material and an organic electroluminescent device and their applications. Background Art

[0002] Since the beginning of the 21st century, with the rapid advancement of technology and the continuous improvement of people's living standards, traditional flat-panel displays have been unable to meet the diverse needs of future life. There is an urgent need for a new generation of flat-panel displays with superior performance. Among the many emerging display technologies, displays using organic light-emitting diodes (OLEDs) have stood out. OLED display technology is based on the electroluminescence principle of organic materials. Under the influence of an electric field, holes and electrons in organic materials recombine and release energy, which stimulates photons to emit light. This unique light-emitting mechanism gives OLED displays many unparalleled advantages. Their small size enables thinner and more compact electronic devices, while their wide viewing angle greatly enhances viewing comfort and convenience. Due to these outstanding advantages, OLED displays have shown extremely broad application prospects in a wide range of display fields, including smartphones, tablets, TVs, and wearable devices.

[0003] Generally speaking, the basic structure of an OLED display device includes a substrate and red (R), green (G), and blue (B) light-emitting pixels arranged on the substrate. In order to achieve effective control and driving of the pixels, these three light-emitting pixels are usually connected in series to form a common layer. However, there is a problem that cannot be ignored in the design of this common layer. Because the common layer is through-the-surface, when the device is powered on, during the hole transmission process, the current that should theoretically be transmitted vertically will leak horizontally due to the mutual influence between pixels, that is, horizontal conduction occurs. In this case, the current will be transmitted from the current sub-pixel to the adjacent sub-pixel, causing the adjacent pixel to be accidentally lit and generating lateral crosstalk between adjacent sub-pixels.

[0004] This lateral crosstalk problem has a serious negative impact on display quality. For example, when a green pixel is adjacent to a red pixel, green light will mix into the red pixel, causing the red light that the red pixel should emit to become impure. Especially at low grayscale levels, the brightness deviation of the sub-pixels caused by this lateral crosstalk current can become extremely significant. This phenomenon directly prevents the display panel from accurately adjusting the white light within the specified specification range in the white screen color coordinates. This in turn causes a series of serious problems such as reduced color gamut, color shift, and image display anomalies, significantly reducing display quality and affecting the user's visual experience. Therefore, how to effectively reduce lateral leakage in OLED display devices has become a pressing issue in the current OLED display technology field. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides an organic electroluminescent material, an organic electroluminescent device, and applications thereof. The organic electroluminescent material can be used as a functional layer of an organic electroluminescent device, with 9-alkyl-9-phenyl-9H-fluorene as a parent core, directly connected to an aromatic amine on the parent core, one side chain of the aromatic amine being an aromatic or heteroaryl group, and the other side chain being 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 low lateral leakage, which can reduce the lateral leakage of adjacent pixels in the device, resulting in adjacent pixels being lit, lateral crosstalk between adjacent sub-pixels, and affecting color display. The organic electroluminescent material of the present invention, as a functional layer of an organic electroluminescent device, can solve problems such as color display and abnormal screen display caused by lateral leakage of OLED display devices.

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

[0007] The first aspect of the present invention provides an organic electroluminescent material having a compound structure shown in Formula I:

[0008] ;

[0009] 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;

[0010] 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;

[0011] 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;

[0012] R1 is independently selected from C1-C 16 Alkyl groups which may or may not be substituted with deuterium;

[0013] 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;

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

[0015] In one embodiment of the present invention, 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.

[0016] In one embodiment of the present invention, R1 is independently selected from C1-C6 alkyl groups which are substituted or unsubstituted with deuterium;

[0017] 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.

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

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

[0020] ;

[0021] wherein R1 is independently selected from methyl substituted or unsubstituted by deuterium, ethyl substituted or unsubstituted by deuterium, propyl substituted or unsubstituted by deuterium, and tert-butyl substituted or unsubstituted by deuterium;

[0022] 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 (TMS), substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl;

[0023] R4 is independently selected from substituted or unsubstituted benzene;

[0024] Ar1 is independently selected from the following substituent groups;

[0025]

[0026]

[0027] Furthermore, the hydrogen in the above groups may be independently substituted by deuterium or not;

[0028] *Indicates the position where the group is attached.

[0029] In one embodiment of the present invention, the term "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 the term "heteroaryl" refers to 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 taking into account the number of carbon atoms in the substituents.

[0030] The term "substituted" means substituted with 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, furyl, pyrrolyl, benzothienyl, benzofuranyl, pyridyl, indolyl, cyclopentanyl, cyclohexanyl, adamantane, or substituted with two or more of the substituents shown above linked together, or having no substituents.

[0031] In one embodiment of the present invention, the compound represented by the 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, the definitions of Ar1, Ar2, L, R1, R2, and R3 in the above formula are the same as those mentioned above and are not 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) were dissolved in toluene solution, and sodium tert-butoxide (2.00eq), tris(dibenzylideneacetone)dipalladium (0.01eq), and tri-tert-butylphosphine (0.05eq) were added, stirred evenly, heated to 90-110°C, and refluxed for 4-6h; after the reaction, the temperature was slightly lowered, and the mixture was filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, the organic phase was retained, and 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 5h to obtain intermediate 1.

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

[0055] Step 3): Under nitrogen protection, intermediate 2 (1eq) and intermediate 1 (1.3-1.4eq) were dissolved in toluene solution, and sodium tert-butoxide (2.00eq), tris(dibenzylideneacetone)dipalladium (0.01eq), and tri-tert-butylphosphine (0.05eq) were added, stirred evenly, heated to 90-110°C, and refluxed for 4-6h; after the reaction was completed, the temperature was slightly lowered, and the mixture was filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, the organic phase was retained, and the aqueous phase was then 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 placed in a 60°C oven to dry 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, video cameras, 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 mother core, and is directly connected to an aromatic amine on the mother core, wherein one side chain of the aromatic amine is an aromatic or 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 lateral leakage of the luminescent material is small, which can reduce the lateral leakage of adjacent pixels in the device and the phenomenon of lateral conduction, thereby avoiding the adjacent pixels in the display device being lit and the generation of lateral crosstalk between adjacent sub-pixels, resulting in the phenomenon of reduced color gamut of the screen, color shift, and affecting color display. The organic electroluminescent material of the present invention is used as a functional layer of an organic electroluminescent device, which can solve the problems of color display and abnormal screen display caused by lateral leakage of OLED display devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0061] Figure 1 is the H NMR spectrum of compound 17.

[0062] Figure 2 Transverse current IV test curves of compounds 17, 18, 256 and comparative compounds 3 and 4 at 0-12V voltage. DETAILED DESCRIPTION

[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 related drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0064] 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 value.

[0065] Reference common knowledge is as follows:

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

[0067] Organic Chemistry and Photoelectric Materials Experimental Tutorial, Chen Runfeng, Southeast University Press, 2019-11-00, ISBN: 9787564184230, page 174.

[0068] The features and performance of the present invention will be further described in detail below with reference to the embodiments.

[0069] Example 1

[0070] Synthesis of compound 17:

[0071] ;

[0072] The specific synthesis steps are as follows:

[0073] Step 1): Under nitrogen protection, raw material A-17 (1.3eq) and raw material B (1.0eq) were dissolved in toluene solution, and sodium tert-butoxide (2.00eq), tris(dibenzylideneacetone)dipalladium (0.01eq), and tri-tert-butylphosphine (0.05eq) were added, stirred evenly, heated to 110°C, and refluxed for 6h; after the reaction, the temperature was slightly lowered, and the mixture was filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, the organic phase was retained, and 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 5h to obtain intermediate 1 (yield: 82.4%).

[0074] Step 2): Under a nitrogen environment, the raw material C-17 (1.0eq) and the raw material D-17 (1.0eq) were added to a mixed solution of toluene, ethanol and water, and potassium carbonate (2.2eq) and tetrakis(triphenylphosphine)palladium (0.01eq) were added thereto. The mixture was stirred evenly, heated to 90°C, and refluxed for 8 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was slightly lowered and filtered using diatomaceous earth to remove salt and catalyst. The filtrate was cooled to room temperature and washed three times with water. The organic phase was retained and the aqueous phase was extracted with dichloromethane. The organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum ether was used as an eluent. The intermediate 2 was purified by column chromatography (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, and sodium tert-butoxide (2.00 eq), tris(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 110°C, and refluxed for 6 hours; after the reaction was completed, the temperature was slightly lowered, and the product was filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate; after the organic phases were combined, they were dried over 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 hours 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 an ESI source. 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: Measured values: C, 90.91; H, 7.16; N, 2.02.

[0080] Preparation of 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 the above-mentioned Example 1, and they are not described here one by one.

[0081] In order to further describe the present invention, more specific application examples are listed below.

[0082] Device Preparation Example 1

[0083] Preparation of red organic electroluminescent devices

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

[0085] a. ITO anode: An ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was cleaned in distilled water three times, ultrasonically washed for 40 minutes, and then repeatedly cleaned with distilled water three times, ultrasonically washed for 20 minutes. After washing, ultrasonically washed with methanol, acetone, and isopropanol in sequence (5 minutes each time), dried, and then transferred to a plasma cleaner for washing for 5 minutes. It was then sent to an evaporator and other functional layers were sequentially evaporated on it using the substrate as the anode.

[0086] b. HIL (hole injection layer): HT-1 and P-dopant were vacuum evaporated at a rate of 1 Å / s to form a hole injection layer. The evaporation rate ratio of HT-1 to P-dopant was 97:3, and the thickness was 10 nm.

[0087] c. HTL (hole transport layer): 1.5 / s evaporation rate, 125nm HT-1 was vacuum evaporated on the hole injection layer as a hole transport layer.

[0088] d. Prime (luminescence auxiliary layer): Compound 17 provided in the above example was vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s to form a luminescence auxiliary layer with a thickness of 100 nm.

[0089] e. EML (Emitting Layer): A host material (Host-1 and Host-2) and a dopant material (Dopant-1) with a total thickness of 40 nm were vacuum-deposited on the light-emitting auxiliary layer at a deposition rate of 1 Å / s. The deposition rate ratio of the host material to the dopant material was 97:3, and the deposition rate ratio of Host-1 to Host-2 in the host material was 4:6. The chemical formulas of Host-1, Host-2, and Dopant-1 are shown below.

[0090] f. HBL (hole blocking layer): A hole blocking layer HB-1 with a thickness of 5 nm was vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s.

[0091] g. ETL (electron transport layer): ET-1 and Liq were vacuum evaporated on the hole blocking layer with a thickness of 30 nm at a deposition rate of 1 Å / s, where the deposition rate ratio of ET-1 to Liq was 50:50.

[0092] h. EIL (electron injection layer): A Yb film with a thickness of 1 nm was vacuum-deposited on the electron transport layer at an evaporation rate of 0.5 Å / s to form an electron injection layer.

[0093] i. Cathode: 13 nm of magnesium and silver were evaporated at an evaporation rate ratio of 1 Å / s, with an evaporation rate ratio of 1:9 to obtain a cathode.

[0094] j. CPL (light extraction layer): CPL-1 with a thickness of 60 nm was vacuum-deposited on the cathode at a deposition rate of 1 angstrom / second as a light extraction layer.

[0095] K. Package the vapor-deposited substrate: First, use the glue coating equipment to coat the cleaned cover with UV glue, then move the coated cover to the pressing section, place the vapor-deposited substrate on the upper end of the cover, and finally bond the substrate and cover with the bonding equipment, and complete the light curing of the UV glue at the same time.

[0096] The structures of HT-1, P-dopant, Host-1, Host-2, Dopant-1, HB-1, ET-1, and CPL-1 used in the device preparation example 1 are as follows:

[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 light-emitting auxiliary layer was evaporated to prepare the corresponding organic electroluminescent devices, which are respectively recorded as device preparation examples 2-12.

[0100] Device Comparison Examples 1-4

[0101] The preparation method of the organic electroluminescent device is the same as that in the above-mentioned device preparation example 1, except that the compound 17 in the device preparation example 1 is replaced by compounds a, b, c, and d, wherein the structural formulas of compounds a, b, c, and d are as follows:

[0102]

[0103] The driving voltage, luminous efficiency and lifespan of the organic electroluminescent devices obtained in the device preparation examples 1-12 and the device control examples 1-4 were characterized at a brightness of 6000 (nits). The test results are shown in Table 1 below.

[0104] Table 1. Test results of luminescence characteristics of organic electroluminescent devices of device preparation examples 1-12 and device control examples 1-4

[0105] (Brightness value is 6000 nits)

[0106]

[0107] As can be seen from the data in Table 1, compared with the organic electroluminescent devices provided in device control examples 1 to 4 and prepared using the luminescent auxiliary materials provided by the present invention, the luminescent auxiliary materials provided by the present invention have better device life than the existing organic electroluminescent devices, which is 2 to 5% longer than 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 for this is that the compound material provided by the present invention has lower lateral leakage than other compounds, which can reduce the probability of lateral leakage between adjacent pixels in the device, avoiding the phenomenon that adjacent pixels are lit and lateral crosstalk occurs between adjacent sub-pixels, thereby affecting color display.

[0109] The present invention is further explained below using theoretical calculation simulation, preparation of a comb-shaped substrate, and testing of lateral current.

[0110] Theoretical calculation simulation

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

[0112] The x-axis mobility represents the lateral current of the compound.

[0113] Table 2

[0114]

[0115] From theoretical calculations, it can be concluded that the smaller the molecular orientation parameter, the greater the z-axis mobility, the smaller the x-axis mobility, and the smaller the lateral current.

[0116] Application Example 1

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

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

[0119] Chemical formula of P-dopant:

[0120] .

[0121] Application Example 2-104

[0122] Application Examples 2-104 were prepared according to the above-mentioned substrate preparation method, and Compound 17 was replaced by the compounds corresponding to Application Examples 2-104, respectively. See Table 3 for details.

[0123] Comparative Examples 1-22

[0124] According to the above-mentioned method for preparing the substrate, Formula I is replaced by the corresponding compounds, except that Formula I is replaced by Comparative Compound 1-22, wherein the structural formula of Comparative Compound 1-22 is as follows, i.e., Comparative Example 1-22:

[0125]

[0126]

[0127] The prepared substrate was subjected to a current-voltage (IV) test using an IVL tester at room temperature. The voltage was set to 0-12V with a step size of 0.1. The results are shown in Table 3:

[0128] Table 3. Transverse current test results of materials in application examples and comparative examples at 12V voltage

[0129]

[0130]

[0131]

[0132]

[0133] Figure 2 The lateral current IV test curves of compound 17, compound 18, compound 256, comparative compound 3 and comparative compound 4 under 0-12V voltage can be seen. The lateral currents of compound 17 and compound 18 are smaller than those of compound 256, and much smaller than those of comparative compound 3 and comparative compound 4.

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

[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 mother core, and is directly connected to the aromatic amine on the mother core. One side chain of the aromatic amine is an aromatic 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, which can reduce the lateral leakage of adjacent pixels in the device, resulting in adjacent pixels being lit, and lateral crosstalk between adjacent sub-pixels, affecting the color display.

[0136] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0137] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one 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. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to 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 having a structure shown in the following formula I-1: ； wherein R1 is independently selected from methyl substituted or unsubstituted by deuterium, ethyl substituted or unsubstituted by deuterium, propyl substituted or unsubstituted by deuterium, and tert-butyl substituted or unsubstituted by deuterium; R2 and R3 are independently selected from the following substituents: hydrogen, methyl, ethyl, propyl, tert-butyl, cyano, fluoro, trimethylsilyl, phenyl, naphthyl, biphenyl; Ar2 is independently selected from benzene, naphthalene, and dibenzofuran; Ar1 is independently selected from the following substituent groups; Furthermore, the hydrogen atoms in the above groups may be independently substituted by deuterium or not; * indicates the connection position of the group.

2. 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 1-140: 。 3. 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 2.

4. Use of the organic electroluminescent material according to any one of claims 1 to 2 or the organic electroluminescent device according to claim 3 in a smartphone, computer, television, car screen, wearable device, computer monitor, and medical monitor.

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