Compound with electron transport function and organic electroluminescent device containing compound

Abstract

The invention provides a compound with an electron transport function and an organic electroluminescent device containing the compound. The compound with the electron transport function has a structure as shown in a formula I. Triazine is used as a parent nucleus, and an alkyl fluorenyl group and a cyano substituent group are connected to the parent nucleus through naphthyl in an ortho-position mode to serve as side chains; the obtained compound can be used as a material of an electron transport layer or a hole blocking layer, and has the advantages of reducing driving voltage, improving luminous efficiency and prolonging service life.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials technology, and relates to a compound with electron transport function and an organic electroluminescent device containing the compound. Background Technology

[0002] With the rapid development of information technology, especially the deep integration of cutting-edge technologies such as artificial intelligence, the Internet of Things, and 5G, people have set higher and newer goals and requirements for the performance of information display systems. In today's digital age, display devices are no longer just windows for information transmission, but also core hubs for human-computer interaction. Therefore, how to endow displays with higher brightness, finer resolution, wider viewing angles, and lower energy consumption has become a research hotspot of common concern for global research institutions and industries. Consumers' pursuit of the ultimate visual experience, as well as their emphasis on device battery life and portability, has further driven the evolution of display technology to a higher level.

[0003] Among numerous emerging display technologies, Organic Light Emitting Diode (OLED) technology, with its unique advantages such as self-illumination, high contrast, fast response speed, and flexible folding capability, has gradually moved from the laboratory to large-scale industrial applications. Currently, OLED screens are widely used in high-end display fields such as smartphones, smart wearable devices, high-end automotive display systems, and professional computer monitors. Furthermore, to meet people's dual demands for immersive large-screen experiences and ultimate product portability, an increasing number of global technology giants and materials companies are actively investing heavily in the development of foldable, rollable, and even stretchable OLED screens. This breakthrough in flexible display technology will not only completely change the form factor design of end products but also provide more ideal display solutions for emerging applications such as Virtual Reality (VR) and Augmented Reality (AR).

[0004] The core working principle of OLED devices is to directly convert electrical energy into light energy by applying electricity to organic electroluminescent materials. A complete organic light-emitting device typically consists of a transparent anode (such as ITO), a metal cathode, and multiple layers of organic functional layers sandwiched between them. These organic layers have a precise structure and work together, generally including a hole injection layer, a hole transport layer, an emissive layer, an electron transport layer, and an electron injection layer. Among these, the electron transport material plays a crucial role, mainly responsible for regulating the injection rate and amount of electrons from the cathode to the emissive layer.

[0005] For high-performance electron transport materials, their design and selection have strict requirements: 1. Energy level matching: The lowest unoccupied molecular orbital (LUMO) energy level should be as small as possible and well matched with the work function of the cathode material to minimize the electron injection barrier and promote efficient electron injection and transport. 2. Electron affinity: The molecular structure usually needs to contain electron-withdrawing groups (such as halogens, pyridines, triazines, triazoles, hydroxyl groups, etc.) to enhance the electron affinity of the material, which is beneficial for capturing and transporting electrons. 3. Hole blocking ability: The highest occupied molecular orbital (HOMO) energy level should be as large as possible (i.e., deeper) to form a higher barrier, effectively blocking holes in the emitting layer from leaking to the cathode, thereby allowing more holes and electrons to recombine in the emitting layer, forming excitons and radiating light, improving the luminous efficiency of the device. 4. Stability and mobility: The material also needs to have good thermal stability, chemical stability, and high electron mobility to ensure the reliability and performance consistency of the device under long-term operation.

[0006] However, despite significant progress in OLED technology, the field still faces several key challenges. Currently, the variety of high-performance organic materials suitable for use as electron transport layers remains relatively limited, particularly in balancing high efficiency, long lifespan, and low cost. The improvements in device lifespan and luminous efficiency achieved by existing organic electroluminescent materials have not yet fully met the stringent requirements of high-end applications. Therefore, developing novel high-performance organic electron transport materials with higher electron mobility, superior energy level structures, and enhanced stability has become paramount for promoting the further development and industrialization of OLED technology. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a compound with electron transport functionality and an organic electroluminescent device containing the same. The present invention uses a triazine core with alkyl fluorenyl groups and cyano-substituted groups attached at the ortho-position of a naphthyl group as side chains. The resulting compound can be used as a material for an electron transport layer or a hole blocking layer, offering advantages such as reduced driving voltage, improved luminous efficiency, and extended lifespan.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] On one hand, the present invention provides a compound having electron transport function, the compound having the structure shown in Formula I:

[0010] ,

[0011] Wherein, R1 is independently selected from substituted or unsubstituted C1-C10 alkyl groups;

[0012] R2 is independently selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom is one or both of O, S, and N.

[0013] Ar1 is independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C6-C30 heteroaryl, and its heteroatom is one or more of O, S, N, Si, Ge, and Se.

[0014] Ar2 is independently selected from C6-C30 aryl groups substituted with cyano or C6-C30 heteroaryl groups substituted with cyano, and its heteroatom is one or more of O, S, N, Si, Ge, and Se.

[0015] In Formula I, all hydrogen atoms are either substituted with deuterium or not substituted with deuterium.

[0016] Furthermore, R1 is independently selected from substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl;

[0017] R2 is independently selected from substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, and its heteroatom is one or two of S, N, and Si.

[0018] Ar1 is independently selected from substituted or unsubstituted C6-C18 aryl or substituted or unsubstituted C6-C18 heteroaryl, and its heteroatom is one or more of O, S, N, Si, Ge, and Se.

[0019] Ar2 is independently selected from C6-C30 aryl groups substituted with cyano or C6-C30 heteroaryl groups substituted with cyano, wherein the heteroatom is one or more of O, S, and N.

[0020] Furthermore, R2 is selected from substituted or unsubstituted groups of the following:

[0021] ;

[0022] The wavy line represents the connection position of the group. Except for the already marked connection positions of the substituent groups, the connection positions of other groups are any substituted positions.

[0023] The terms “substituted or unsubstituted C6-C30 aryl”, “substituted or unsubstituted C6-C18 aryl”, “substituted or unsubstituted C6-C30 heteroaryl”, “substituted or unsubstituted C6-C18 heteroaryl”, and “substituted or unsubstituted C1-C6 alkyl” refer to the number of carbon atoms in the aryl, heteroaryl, and alkyl groups, indicating the total number of carbon atoms constituting the unsubstituted aryl or 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 substituents.

[0024] The term "substitution" means substitution by one, two or more substituents selected from the following: hydrogen, deuterium, halogen, cyano, trifluoromethyl, trimethylsilyl, trimethylgermanium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, phenyl, naphthyl, anthracene, phenanthrene, thiophene, furanyl, pyrrole, benzothiophene, benzofuranyl, pyridyl, indolyl, cyclopentyl, cyclohexyl, adamantane, or substitution by two or more substituents linked together from the substituents listed above.

[0025] In one embodiment of the present invention, the compound having electron transport function is any one of the following structures, but is not limited thereto:

[0026]

[0027]

[0028] .

[0029] Secondly, the present invention also provides a method for synthesizing a compound with electron transport function. The organic compound described in this invention can be prepared by methods known to those skilled in the art. Alternatively, the following reaction procedure is preferred for preparation, and the specific synthetic route is as follows:

[0030] ;

[0031] Hal1, Hal2, Hal3 and Hal4 are selected from halogens, and the other groups are the same as those defined above, so they will not be described again.

[0032] Synthesis route:

[0033] Step 1:

[0034] Under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0-1.5 eq) were dissolved in 1,4-dioxane, and Pd2(dba)3 (0.02 eq), X-phos (2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.05 eq) and potassium acetate (2.5-3.0 eq) were added. The mixture was heated to 90-100℃ and refluxed for 12-24 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 1.

[0035] Step 2:

[0036] Under nitrogen protection, intermediate 1 (1.0 eq) and starting material C (1.0-1.2 eq) were dissolved in a mixed solution of toluene, ethanol, and water (V:V:V=2:1:1), and Pd(pph3)4 (0.05-0.08 eq) and potassium carbonate (2.5-3.0 eq) were added. The mixture was heated to 90-100℃ and refluxed for 12-24 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 2.

[0037] Step 3:

[0038] Under nitrogen protection, intermediate 2 (1.0 eq) and starting material B (1.0-1.5 eq) were dissolved in 1,4-dioxane, and Pd2(dba)3 (0.02 eq), X-phos (0.05 eq) and potassium acetate (2.5-3.0 eq) were added. The mixture was heated to 90-100℃ and refluxed for 12-24 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 3.

[0039] Step 4:

[0040] Under nitrogen protection, intermediate 3 (1.0 eq) and starting material D (1.0-1.2 eq) were dissolved in a mixed solution of toluene, ethanol, and water (V:V:V=2:1:1), and Pd(pph3)4 (0.05-0.08 eq) and potassium carbonate (2.5-3.0 eq) were added. The mixture was heated to 90-100 °C and refluxed for 12-24 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain the compound shown in Formula I.

[0041] Thirdly, the present invention also provides an organic electroluminescent device, comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode; wherein the hole blocking layer and / or electron transport layer contains a compound with electron transport function having the structure shown in Formula I above.

[0042] Preferably, the organic layer further includes one or a combination of at least two of the following: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, an electron injection layer, and a capping layer.

[0043] The structure of the organic electroluminescent device is not limited to this, and may include fewer or more organic layers.

[0044] In one embodiment of the present invention, when manufacturing an organic electroluminescent device, an organic layer is formed by vacuum evaporation or solution coating.

[0045] In one embodiment of the present invention, the solution coating method includes one or more of spin coating, dip coating, blade coating, inkjet printing, screen printing, spray coating and roller coating, but is not limited thereto.

[0046] In one embodiment of the present invention, the organic electroluminescent device is classified into top-emitting type, bottom-emitting type or bidirectional-emitting type according to the material used.

[0047] As an anode material, materials with a large work function are usually preferred to facilitate the injection of holes into the organic material layer.

[0048] In one embodiment of the invention, specific examples of anode materials that can be used include: metals, such as vanadium, chromium, copper, zinc and gold, or alloys thereof; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO:Al or SnO2:Sb; conductive polymers, such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxo)thiophene] (PEDOT), polypyrrole and polyaniline, but not limited thereto.

[0049] Hole injection materials are materials that advantageously receive holes from the anode at low voltages, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0050] In one embodiment of the present invention, the material of the hole injection layer includes metalloporphyrin, oligothiophene, arylamine-based organic materials, hexanitrile hexaazabenzophenanthrene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, and conductive polymers based on polyaniline and polythiophene, but is not limited thereto, and may also include other compounds capable of p-doping.

[0051] The material of the hole transport layer is one that can receive holes from the anode or hole injection layer and transport the holes to the light-emitting layer, and a material with high hole mobility is suitable.

[0052] In one embodiment of the present invention, the material of the hole transport layer includes, but is not limited to, arylamine-based organic materials, conductive polymers, block copolymers having both conjugated and non-conjugated portions.

[0053] The luminescent layer can emit red, green, or blue light and can be formed from phosphorescent or fluorescent materials. The material of the luminescent layer is a material that can emit light in the visible light region by receiving holes and electrons from the hole transport layer and the electron transport layer, respectively, and by combining the holes with the electrons, and is preferably a material with favorable quantum efficiency for fluorescence or phosphorescence.

[0054] In one embodiment of the present invention, the material of the light-emitting layer includes: 8-hydroxyquinoline aluminum ligand (Alq3); carbazole-based compounds; dipolystyrene-based compounds; BAlq; 10-hydroxybenzoquinoline-metal compounds; compounds based on benzocarbazole, benzothiazole, and benzimidazole; polymers based on poly(p-phenylenevinylene) (PPV); spirocyclic compounds; polyfluorene; fluorene, etc., but not limited thereto.

[0055] In one embodiment of the present invention, the light-emitting layer comprises a host material and a dopant material.

[0056] In one embodiment of the present invention, the host material of the light-emitting layer includes fused aromatic ring derivatives, heterocyclic compounds, etc.

[0057] Specifically, the fused aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentane derivatives, phenanthrene compounds, fluoranthene compounds, etc., and heterocyclic compounds include carbazole derivatives, dibenzofuran derivatives, ladder-type furan compounds, pyrimidine derivatives, etc., however, the materials are not limited to these.

[0058] In one embodiment of the present invention, the doping material of the light-emitting layer includes fluorescent doping and phosphorescent doping.

[0059] For example, it can be selected from aromatic amine derivatives, styrylamine compounds, boron complexes, fluoranthene compounds, metal complexes, etc.

[0060] The hole blocking layer blocks holes from the anode at the interface of the device's light-emitting layer, thereby increasing the probability of electron and hole recombination at the interface and increasing the device's luminous efficiency.

[0061] The compound with the structure shown in Formula I in this invention can be used as a material for a hole blocking layer.

[0062] The electron transport layer can facilitate electron transport. The electron transport material is advantageously used to receive electrons from the cathode and transport them to the light-emitting layer; materials with high electron mobility are preferred.

[0063] The compound with the structure shown in Formula I in this invention can be used as an electron transport layer material.

[0064] The electron injection layer can promote electron injection. The preferred electron injection material is a compound that has the ability to transport electrons, has an electron injection effect from the cathode, has an excellent electron injection effect on the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and, in addition, has excellent thin film forming ability.

[0065] For example, materials for the electron injection layer include fluorenone, anthraquinone dimethane, biphenylquinone, thiam dioxide, azole, diazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenemethane, anthrone and their derivatives, metal complexes, nitrogen-containing 5-membered ring derivatives, etc., but are not limited to these.

[0066] As a cathode material, materials with a small work function are usually preferred to facilitate the injection of electrons into the organic material layer.

[0067] In one embodiment of the present invention, the cathode material includes: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or alloys thereof; multilayer structure materials, such as LiF / Al or LiO2 / Al; and so on, but not limited thereto.

[0068] Fourthly, the present invention also provides applications of organic electroluminescent devices in flat panel displays, computer monitors, medical monitors, televisions, billboards, lamps for internal or external lighting and / or signals, head-up displays, fully transparent or partially transparent displays, flexible displays, laser printers, telephones, mobile phones, tablets, photo albums, personal digital assistants (PDAs), wearable devices, laptops, digital cameras, camcorders, viewfinders, microdisplays, 3D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screens, phototherapy devices, and signs.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] This invention provides a compound with electron transport function. The compound uses a triazine core with alkyl fluorenyl derivatives and cyano substituents attached to it in the ortho-position of a naphthyl group as side chains. The resulting compound can be used as a material for an electron transport layer or a hole blocking layer, and has the advantages of reducing driving voltage, improving luminous efficiency and extending service life. Attached Figure Description

[0071] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound 197 in Example 1 of the present invention. Detailed Implementation

[0072] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0073] It should be noted that the series of palladium-catalyzed coupling reactions in this invention utilize the difference in reactivity between I and Br (which is greater than that of Cl) and the reaction sites are controlled by adjusting the reaction conditions. Furthermore, the reactions are purified by column chromatography or through a silica gel funnel to remove byproducts, yielding the target compound. The following are common knowledge references used in the synthesis of the compounds in this invention:

[0074] Organometallic Chemistry (6th Edition), Robert H. Crabtree, published by East China University of Science and Technology Press, Shanghai, September 00, 2017, ISBN: 978-7-5628-5111-0, page 388.

[0075] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0076] In addition, the values ​​given in the following embodiments are as accurate as possible, but those skilled in the art will understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximation rather than an absolutely accurate value.

[0077] Example 1

[0078] Synthesis of Compound 197

[0079]

[0080] CAS: Reactant A-197: 382602-31-5

[0081] CAS: Reactant B-197: 73183-34-3

[0082] CAS: Reactant C-197: 71436-66-3

[0083] CAS: Reactant D-197: 2260561-71-3

[0084] Step 1:

[0085] Under nitrogen protection, raw materials A-197 (1.0 eq) and B-197 (1.5 eq) were dissolved in 1,4-dioxane, and Pd2(dba)3 (0.02 eq), X-phos (0.05 eq) and potassium acetate (2.5 eq) were added. The mixture was heated to 100 °C and refluxed for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring and standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 1 (yield: 85.1%).

[0086] Step 2:

[0087] Under nitrogen protection, intermediate 1 (1.0 eq) and starting material C-197 (1.2 eq) were dissolved in a mixed solution of toluene, ethanol, and water (V:V:V=2:1:1), and Pd(pph3)4 (0.08 eq) and potassium carbonate (3.0 eq) were added. The mixture was heated to 90 °C and refluxed for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring and standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 2 (yield: 83.4%).

[0088] Step 3:

[0089] Under nitrogen protection, intermediate 2 (1.0 eq) and starting material B-197 (1.5 eq) were dissolved in 1,4-dioxane, and Pd2(dba)3 (0.02 eq), X-phos (0.05 eq) and potassium acetate (2.5 eq) were added. The mixture was heated to 100 °C and refluxed for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring and standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain intermediate 3 (yield: 86.6%).

[0090] Step 4:

[0091] Under nitrogen protection, intermediate 3 (1.0 eq) and starting material D-197 (1.2 eq) were dissolved in a mixed solution of toluene, ethanol, and water (V:V:V=2:1:1), and Pd(pph3)4 (0.08 eq) and potassium carbonate (3.0 eq) were added. The mixture was heated to 90 °C and refluxed for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was cooled to room temperature, and purified water and dichloromethane were added. After stirring and standing, the mixture was allowed to separate into layers. After separation, the mixture was purified by column chromatography to obtain the compound shown in Formula I (yield: 81.7%).

[0092] Characterization:

[0093] HPLC purity: >99.8%;

[0094] Test value ((ESI, m / Z): [M+H]) + ): 652.41;

[0095] Elemental analysis:

[0096] Test values: C, 86.44; H, 5.02; N, 8.64;

[0097] The proton NMR spectrum of compound 197 is as follows: Figure 1 As shown.

[0098] Other compounds in this application can be obtained by referring to the synthetic methods listed in the above examples, so they will not be listed here again. The mass spectrometer was a Waters XEVO TQD, low precision, ESI source for testing.

[0099] Device Example 1 - Compound 197 as an electron transport material for the fabrication of organic electroluminescent devices

[0100] a. ITO Anode: A 150nm thick ITO (Indium Tin Oxide)-Ag-ITO (Indium Tin Oxide) glass substrate is cleaned twice with distilled water, ultrasonically washed for 30 minutes, then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it is baked in a vacuum oven at 220℃ for 2 hours. After baking, it is cooled before use. Using this substrate as the anode, a vapor deposition process is performed to deposit other functional layers sequentially on it.

[0101] b. HIL (Hole Injection Layer): Hole injection layer materials HT-1 and P-dopant are vacuum-deposited at a deposition rate of 1 Å / s. The deposition rate ratio of HT-1 to P-dopant is 97:3, and the thickness is 10 nm.

[0102] c. HTL (Hole Transport Layer): HT-1 of 120 nm was vacuum-deposited on the hole injection layer at a deposition rate of 1.5 Å / s as the hole transport layer.

[0103] d. Prime (light-emitting auxiliary layer): Prime-1 of 5 nm was vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a light-emitting auxiliary layer.

[0104] e. EML (Light Emitting Layer): A host material (Host-1) and a dopant material (Dopant-1) with a thickness of 30 nm are vacuum-deposited on the light-emitting auxiliary layer at a deposition rate of 1 Å / s. The deposition rate ratio of Host-1 to Dopant-1 is 97:3.

[0105] f. HB (hole blocking layer): HB-1 with a thickness of 5.0 nm is vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s as a hole blocking layer.

[0106] g. ETL (Electron Transport Layer): Compound 1 and Liq with a thickness of 30 nm are vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s, with the deposition rate ratio of compound 197 to Liq being 50:50.

[0107] h. EIL (Electron Injection Layer): A Yb film with a thickness of 1.0 nm is deposited on the electron transport layer at a deposition rate of 0.5 Å / s to form the electron injection layer.

[0108] i. Cathode: Magnesium and silver with a thickness of 13 nm are deposited on the electron injection layer at a deposition rate of 1 Å / s, with a deposition rate ratio of magnesium to silver of 1:9, to obtain the cathode.

[0109] j. Optical extraction layer: CPL-1 with a thickness of 70 nm is vacuum-deposited on the cathode at a deposition rate of 1 Å / s as the optical extraction layer. The chemical formula of CPL-1 is shown below.

[0110] k. Encapsulate the vapor-deposited substrate: First, use a coating equipment to coat the cleaned cover plate with UV adhesive; then, move the coated cover plate to the lamination section and place the vapor-deposited substrate on the top of the cover plate; finally, laminate the substrate and cover plate together under the action of the lamination equipment, while simultaneously completing the UV adhesive photocuring.

[0111] The structure of the materials used in the device is as follows:

[0112] .

[0113] Application Example 2-57

[0114] Organic electroluminescent devices of application examples 2-57 were prepared according to the above-described method for preparing organic electroluminescent devices, except that compound 197 in device example 1 was replaced with compounds 1, 4, 7, 8, 13, 17, 19, 23, 31, 33, 34, 41, 47, 55, 61, 66, 69, 70, 79, 84, 89, 100, 109, 112, 117, 123, 125, 131, 138, 141, 143, 145, 148, 154, 157, 160, 169, 173, 180, 184, 189, 194, 201, 206, 210, 212, 215, 220, 225, 231, 237, 244, 249, 250, 257 and 275 to form an electron transport layer.

[0115] Comparative Examples 1-12

[0116] Organic electroluminescent devices were prepared according to the above-described method, except that compound 197 in Application Example 1 was replaced with comparative compounds a and i, respectively, wherein the structural formulas of comparative compounds a and i are as follows:

[0117]

[0118] The driving voltage, luminous efficiency, BI value, and lifetime of the organic electroluminescent devices obtained by applying Examples 1-57 and Comparative Examples 1-12 at a brightness of 1000 nits were characterized. The test results are shown in Table 1 below:

[0119] Table 1. Results of luminous properties test (luminance value 1000 nits)

[0120]

[0121]

[0122] Those skilled in the art will know that in blue top-emitting devices, luminous efficiency is greatly affected by chromaticity. Therefore, taking into account the influence of chromaticity on efficiency, the ratio of luminous efficiency to CIEy is defined as the BI value, i.e., BI = (cd / A) / CIEy.

[0123] The compound with electron transport function provided by the present invention uses triazine as the core and connects alkyl fluorenyl derivatives and cyano derivatives as side chains on it via ortho-linked naphthyl groups. The resulting compound can be used as a material for electron transport layer or hole blocking layer, and has the advantages of reducing driving voltage, improving luminous efficiency and extending service life.

[0124] As can be seen from Table 1, compared with the existing organic electroluminescent devices provided by Device Comparative Examples 1 to 12, the OLED devices prepared using the compounds provided in the embodiments of the present invention (Examples 1 to 53) show a significant advantage in device lifetime, which is increased by 12.6% to 33.6% compared with the comparative examples. At the same time, it also improves the driving voltage and luminous efficiency of the device, with the driving voltage reduced by 2.9% to 10.3% and the luminous efficiency increased by 7.5% to 16.4%.

[0125] Among them, comparative compounds c, d, and h are parallel comparative examples with compounds 70, 69, and 1 of the present invention. The difference is that the corresponding positions of compounds R1 and R2 of the present invention are at least one alkyl group or both of them are alkyl groups, while the corresponding positions of the comparative compounds are diphenyl or spirocyclic structures. The aryl group in the comparative compounds does not play a conjugating role, but instead increases the molecular weight of the compound, resulting in a higher evaporation temperature, which can easily cause material cracking, affect the life of the device, and reduce the life of the device. At the same time, the luminous efficiency is reduced to a certain extent.

[0126] Comparative compounds g and j are parallel comparative examples with compounds 143 and 197 of the present invention. The difference lies in the substitution sites of the fluorenyl derivative or triazine derivative on the naphthalene ring. In the present invention, the fluorenyl derivative and triazine derivative are substituted at positions 1 and 2 on the naphthalene ring, respectively, while the comparative compounds are substituted at other sites. Different substitution sites lead to different electron mobilities of the compounds, thereby affecting the efficiency and driving voltage of the device. Compared with the comparative compounds, the luminous efficiency and lifetime of the compounds of the present invention are improved to a certain extent, and the driving voltage is also improved to a certain extent.

[0127] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in 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 compound with electron transport function, characterized in that, The compound with electron transport function has the structure shown in Formula I: ， Wherein, R1 is independently selected from substituted or unsubstituted C1-C10 alkyl groups; R2 is independently selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom is one or both of O, S, and N. Ar1 is independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C6-C30 heteroaryl, and its heteroatom is one or more of O, S, N, Si, Ge, and Se. Ar2 is independently selected from C6-C30 aryl groups substituted with cyano or C6-C30 heteroaryl groups substituted with cyano, and its heteroatom is one or more of O, S, N, Si, Ge, and Se. In Formula I, all hydrogen atoms are either substituted with deuterium or not substituted with deuterium.

2. The compound with electron transport function according to claim 1, characterized in that, R1 is independently selected from substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl; R2 is independently selected from substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, and its heteroatom is one or two of S, N, and Si. Ar1 is independently selected from substituted or unsubstituted C6-C18 aryl or substituted or unsubstituted C6-C18 heteroaryl, and its heteroatom is one or more of O, S, N, Si, Ge, and Se. Ar2 is independently selected from C6-C30 aryl groups substituted with cyano or C6-C30 heteroaryl groups substituted with cyano, wherein the heteroatom is one or more of O, S, and N.

3. The compound with electron transport function according to claim 1, characterized in that, R2 is selected from the following groups, whether substituted or unsubstituted: ； The wavy line represents the connection position of the group. Except for the already marked connection positions of the substituent groups, the connection positions of other groups are any substituted positions.

4. The compound with electron transport function according to any one of claims 1-3, characterized in that, "Substitution" means substitution by one, two or more substituents selected from the following: hydrogen, deuterium, halogen, cyano, trifluoromethyl, trimethylsilyl, trimethylgermanium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, phenyl, naphthyl, anthracene, phenanthrene, thiophene, furanyl, pyrrole, benzothiophene, benzofuranyl, pyridyl, indolyl, cyclopentyl, cyclohexyl, adamantane, or substitution by two or more substituents linked together from the substituents listed above.

5. The compound with electron transport function according to any one of claims 1-3, characterized in that, The compound with electron transport function is any one of the following structures: 。 6. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic layer disposed between the anode and the cathode; the organic layer includes a hole blocking layer and / or an electron transport layer; the hole blocking layer and / or the electron transport layer contains a compound with electron transport function as described in any one of claims 1-5.

7. The organic electroluminescent device according to claim 6, characterized in that, The organic layer further includes one or a combination of at least two of the following: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, an electron injection layer, and a capping layer.

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