A large condensed ring organic compound, application thereof, and an organic electroluminescent device comprising the same

Abstract

The present application relates to a kind of big condensed ring organic compound, belong to organic light-emitting material technical field, simultaneously relate to the application of this kind of compound and the organic electroluminescent device comprising it.The organic compound of the present application has the structure shown as formula (1).The compound of the present application takes indolobenzofuran or indolobenzothiophene as parent nucleus and contains arylamine structure, such compound has good transport performance and stability, when being applied to organic electroluminescent device, it is suitable to be used as light-emitting host material, can effectively improve the service life of device.

Description

TECHNICAL FIELD

[0001] The present application relates to an organic compound, belonging to the technical field of organic light-emitting materials, and simultaneously relates to the application of the compound and an organic electroluminescent device comprising the same. BACKGROUND

[0002] In recent years, optoelectronic devices based on organic materials have been developed rapidly and become a hot research topic in the field. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, and the like. Among them, OLEDs have developed particularly rapidly and have achieved commercial success in the field of information display. OLEDs can provide red, green and blue colors with high saturation, and full-color display devices made of them do not require an additional backlight, and have the advantages of bright colors, thinness, softness, and the like.

[0003] The core of an OLED device is a multi-layer thin film structure comprising various functional organic materials. Commonly used functional organic materials include hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, light-emitting host materials, and light-emitting guests (dyes), and the like. When powered on, electrons and holes are injected and transported to the light-emitting region, where they recombine to generate excitons and emit light.

[0004] Common fluorescent emitters mainly utilize singlet excitons generated when electrons and holes combine, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can utilize both triplet and singlet excitons for light emission, and are called phosphorescent emitters, which can have an energy conversion efficiency up to four times higher than that of traditional fluorescent emitters. Thermal activation delayed fluorescence (TADF) technology promotes the conversion of triplet excitons to singlet excitons, and can effectively utilize triplet excitons to achieve high light-emitting efficiency without using metal complexes. Thermal activation sensitized fluorescence (TASF) technology uses a material with TADF properties to sensitize the emitter through energy transfer, which can also achieve high light-emitting efficiency.

[0005] Although products using OLED display technology have been commercialized, there is still a need to continuously improve the performance of the device, such as the service life and efficiency, to meet people's pursuit of higher quality. Therefore, there is an urgent need in the art to develop more types of organic materials for use in organic electroluminescent devices, so that the devices have high light-emitting efficiency, low driving voltage, and long service life. SUMMARY

[0006] In view of the deficiencies of the prior art, one of the purposes of the present application is to provide a compound. The compound has good photoelectric properties when applied to an OLED device.

[0007] To achieve the above object, the present application employs the following technical solutions:

[0008] The present application provides a compound having a structure as shown in formula (1):

[0009]

[0010] In formula (1):

[0011] X is selected from O or S;

[0012] Y1 and Y2 are single bond or NR, and one of Y1 and Y2 is single bond and the other is NR, and the R has a structure as shown in formula (a);

[0013] L1 is selected from at least one of single bond, substituted or unsubstituted C6-C18 arylene, and substituted or unsubstituted C3-C18 heteroarylene;

[0014] Ar1 is substituted or unsubstituted C3-C60 heteroaryl, wherein the heteroatom is N;

[0015] R1, R2 and R3 are independently one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 chain alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl;

[0016] In formula (a):

[0017] L2 is selected from at least one of substituted or unsubstituted C6-C18 arylene, and substituted or unsubstituted C3-C18 heteroarylene;

[0018] Ar2 and Ar3 are each independently selected from at least one of substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl;

[0019] When each of the above-mentioned substituted or unsubstituted groups has a substituent, the substituent is selected from one or a combination of two of deuterium, halogen, cyano, nitro, hydroxyl, amino, aldehyde, ester, C1-C30 chain alkyl, C1-C30 alkoxy, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0020] In the present application, the "substituted or unsubstituted" group can be substituted with one substituent or can be substituted with a plurality of substituents, and when the substituents are a plurality, they can be selected from different substituents. When the same expression is used in the present application, it has the same meaning, and the selection range of the substituents is as described above and will not be described again.

[0021] In the present specification, the expression of Ca~Cb represents that the number of carbon atoms of the group is a~b, and unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0022] In the present specification, "each independently" means that when the subject has a plurality, they can be the same or different.

[0023] In the present application, the expression of a chemical element, unless otherwise specified, generally includes the concept of its isotope, for example, the expression of "hydrogen (H)" includes the concept of its isotope 1 H (protium or H), 2 H (deuterium or D); carbon (C) includes 12 C, 13 C, and the like, which will not be described again.

[0024] In the present application, the heteroatom in the heteroaryl group generally refers to an atom or atom group selected from N, O, S, P, Si, and Se, preferably N, O, and S.

[0025] In the present specification, as examples of halogen, fluorine, chlorine, bromine, iodine, and the like can be given.

[0026] In the present application, the substituted or unsubstituted C6~C60 aryl group includes monocyclic aryl groups and fused ring aryl groups, preferably C6~C30 aryl groups, and further preferably C6~C20 aryl groups. The monocyclic aryl group refers to a group having at least one phenyl group in the molecule, and when there are at least two phenyl groups in the molecule, the phenyl groups are independent of each other and connected by a single bond, and exemplary examples are phenyl, biphenyl, terphenyl, and the like. Specifically, the biphenyl includes 2-biphenyl, 3-biphenyl, and 4-biphenyl; and the terphenyl includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, and m-terphenyl-2-yl. The fused ring aryl group refers to a group having at least two aromatic rings in the molecule, and the aromatic rings are not independent of each other but share two adjacent carbon atoms and are fused to each other. Exemplary examples are naphthyl, anthryl, phenanthryl, indenyl, fluorenyl, fluoranthene, triphenylene, pyrenyl, perylenyl, The naphthyl group includes 1-naphthyl or 2-naphthyl; the anthryl group is selected from 1-anthryl, 2-anthryl and 9-anthryl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetracenyl group is selected from 1-tetracenyl, 2-tetracenyl and 9-tetracenyl. The derivative groups of fluorene are selected from 9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, 9,9'-spirobifluorene and benzofluorenyl.

[0027] In the present application, the substituted or unsubstituted C3-C60 heteroaryl group includes monocyclic heteroaryl group and fused ring heteroaryl group, preferably C3-C30 heteroaryl group, further preferably C4-C20 heteroaryl group, and more preferably C5-C12 heteroaryl group. The monocyclic heteroaryl group refers to a group having at least one heteroaryl group in the molecule. When the molecule contains one heteroaryl group and other groups (such as aryl group, heteroaryl group, alkyl group, etc.), the heteroaryl group and the other groups are independent of each other and connected by a single bond. Examples of the monocyclic heteroaryl group include furanyl group, thienyl group, pyrrolyl group, pyridyl group, etc. The fused ring heteroaryl group refers to a group having at least one aromatic heterocyclic ring and one aromatic ring (aromatic heterocyclic ring or aromatic ring) in the molecule, and the two groups are not independent of each other but are fused to each other by sharing two adjacent atoms. Examples of the fused ring heteroaryl group include benzo furanyl group, benzo thienyl group, isobenzo furanyl group, indolyl group, dibenzo furanyl group, dibenzo thienyl group, carbazolyl group, acridinyl group, isobenzo furanyl group, isobenzo thienyl group, benzocarbazolyl group, azacarbazolyl group, phenothiazinyl group, phenoxazinyl group, 9-phenylcarbazolyl group, 9-naphthylcarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, etc.

[0028] In the present application, the chain alkyl group, if not otherwise specified, includes straight chain alkyl group and branched chain alkyl group. Specifically, the substituted or unsubstituted C1-C30 chain alkyl group, preferably the substituted or unsubstituted C1-C16 chain alkyl group, and more preferably the substituted or unsubstituted C1-C10 chain alkyl group. The substituted or unsubstituted C3-C30 cyclic alkyl group, preferably the substituted or unsubstituted C3-C20 cyclic alkyl group, and more preferably the substituted or unsubstituted C3-C10 cyclic alkyl group. Examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, n-hexyl group, n-octyl group, iso-butyl group, tert-butyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, tert-amyl group, cyclohexyl group, adamantyl group, etc.

[0029] Further, the compound of the present application has a structure as shown in formula (1-1) or formula (1-2):

[0030] Further, the compound of the present application has a structure as shown in formula (1-1) or formula (1-2):

[0031] In formula (1-1), formula (1-2), the definitions of X, L1, L2, Ar1, Ar2, Ar3, R1, R2 and R3 are the same as those in formula (1) or formula (a);

[0032] Preferably, when the above L1, L2, Ar1, Ar2, Ar3, R1, R2 and R3 each independently have a substituent group, the substituent group is selected from one or a combination of two of deuterium, halogen, C1-C10 linear alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl.

[0033] Further preferably, in formula (1), formula (1-1), formula (1-2), Ar1 is a substituted or unsubstituted C3-C30 heteroaryl group containing at least 2 nitrogen atoms;

[0034] More preferably, in formula (1), formula (1-1), formula (1-2), Ar1 is a substituted or unsubstituted C3-C30 heteroaryl group containing 2 or 3 nitrogen atoms in one ring structure.

[0035] Further, in formula (1), formula (1-1), formula (1-2), Ar1 is selected from the following substituted or unsubstituted groups:

[0036]

[0037] wherein "*" represents the connection site of the group,

[0038] When the above Ar1 has a substituent group, the substituent group is selected from one or a combination of two of deuterium, halogen, C1-C10 linear alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl.

[0039] Further, in formula (1), formula (1-1), formula (1-2), Ar1 is selected from the following substituted or unsubstituted groups:

[0040]

[0041]

[0042] wherein "*" represents the connection site of the group,

[0043] When the above group has a substituent group, the substituent group is selected from one of deuterium, halogen, C1-C10 chain alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl or a combination of two of them. Further, the R1, R2and R3are each independently selected from substituted or unsubstituted hydrogen, phenyl, naphthyl, anthryl, phenanthryl, indenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl, When the above group has a substituent group, the substituent group is selected from one of deuterium, halogen, C1-C10 chain alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl or a combination of two of them. Further, the R1, R2and R3are each independently selected from substituted or unsubstituted hydrogen, phenyl, naphthyl, anthryl, phenanthryl, indenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl,

[0044] When the above group has a substituent group, the substituent group is selected from one of deuterium, halogen, C1-C10 chain alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl or a combination of two of them. Further, the R1, R2and R3are each independently selected from substituted or unsubstituted hydrogen, phenyl, naphthyl, anthryl, phenanthryl, indenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl,

[0045] Further, the R1, R2and R3are each hydrogen.

[0046] Further, the Ar2and Ar3are each independently selected from substituted or unsubstituted phenyl, naphthyl, anthryl, phenanthryl, indenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl, When the above group has a substituent group, the substituent group is selected from one of deuterium, halogen, C1-C10 chain alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl or a combination of two of them. Further, the R1, R2and R3are each independently selected from substituted or unsubstituted hydrogen, phenyl, naphthyl, anthryl, phenanthryl, indenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl,

[0047] When the above-mentioned each group with or without substitution has a substituent, the substituent is selected from one or a combination of at least two of deuterium, halogen, C1-C10 chain alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl.

[0048] The design point of the present application is to provide a large fused ring compound with indolobenzofuran or indolobenzothiophene as a parent nucleus (as shown in formula (1)) structure, which has a good rigid structure, better planarity, and good carrier transport capacity. The present application introduces an arylamine structure on the nitrogen of indole. On the one hand, this improves the overall HOMO level of the material and improves the hole injection capacity of the material. On the other hand, the introduction of arylamine also promotes the improvement of the molecular transport capacity. In summary, the material of the present application has good injection and transport capacity, and the performance in the device is lower voltage and higher efficiency.

[0049] In the present application, the expression of the ring structure with a dash through it represents a connection site at any position on the ring structure that can form a bond.

[0050] Furthermore, the compound of the general formula of the present application is preferably the following specific compound, but the present application is not limited to the specific compound shown below:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] As another aspect of the present invention, the application of the compound described above in an organic electroluminescent device is also provided. Specifically, its application as a light-emitting layer material in an organic electroluminescent device is preferred, and its application in a red organic electroluminescent device is even more preferred.

[0070] More preferably, the compound of the present invention is used as the host material of the organic electroluminescent device, and preferably as the host material for red light.

[0071] In addition to organic electroluminescent devices, the compounds of this invention can also be applied to lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper.

[0072] As another aspect of the present invention, an organic electroluminescent device is also provided, comprising a first electrode, a second electrode, and an organic layer inserted between the first electrode and the second electrode, characterized in that the organic layer contains a compound represented by Formula I as described above, or a compound containing at least one of the structures represented by P1 to P212 as described above.

[0073] Specifically, one embodiment of the present invention provides an organic electroluminescent device, including a substrate, and a first electrode, a plurality of light-emitting functional layers, and a second electrode sequentially formed on the substrate; the light-emitting functional layers include a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer, wherein the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and the light-emitting layer is located between the hole transport layer and the electron transport layer; wherein the light-emitting layer includes a host material and a dopant material, the host material including at least one compound of Formula I as described above, or a compound containing at least one of the structures of P1 to P212 as described above.

[0074] The present invention also discloses a display screen or display panel, wherein the display screen or display panel employs the organic electroluminescent device as described above; preferably, the display screen or display panel is an OLED display.

[0075] The present invention also discloses an electronic device having a display screen or display panel, wherein the display screen or display panel employs an organic electroluminescent device as described above. Detailed Implementation

[0076] 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.

[0077] The mass spectrometry characterization data in the following synthesis examples were obtained using a ZAB-HS mass spectrometer manufactured by Micromass, UK.

[0078] The material of this invention can be obtained through the following general formula reaction:

[0079]

[0080] In the above formula, one of Y1 and Y2 is a single bond, and the other is NR, and R has the structure shown in formula (a):

[0081] Detailed Implementation

[0083] Synthesis example 1:

[0084] Synthesis of compound P2

[0085]

[0086] S1 (0.1 mol), S2 (0.11 mol), sodium tert-butoxide (0.15 mol), tris(dibenzylacetone)palladium (0.0005 mol), tri-tert-butylphosphine (0.001 mol), and xylene (400 ml) were added to a reaction flask and heated to 140 °C for 5 h. The reaction was monitored by TLC until complete. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain P2-A.

[0087] P2-A (0.05 mol) and tetrahydrofuran (400 ml) were added to a reaction flask. The temperature was lowered to -78 °C and sec-butyllithium (0.07 mol) was added dropwise. After the addition was complete, the temperature was raised to -30 °C and reacted for 2 h. The temperature was then lowered back to -78 °C and triisopropyl borate (0.1 mol) was added dropwise. After the addition was complete, the temperature was gradually restored to room temperature. The reaction was monitored by TLC until it was complete. After cooling, water and dichloromethane were added for extraction, and the organic phase was concentrated to obtain P2-B.

[0088] P2-B (0.03 mol), 2-chloro-4-phenylquinazoline (0.04 mol), potassium carbonate (0.05 mol), tetrakis(triphenylphosphine)palladium (0.0003 mol), 30 mL of water, and 200 mL of dioxane were refluxed under nitrogen protection for 8 h. After the reaction was complete, water and dichloromethane were added and the mixture was separated. The organic phase was concentrated and purified by column chromatography to obtain P2 (MS, 797.27).

[0089] The following compounds are synthesized using the same method as in Synthesis Example 1, except that the starting materials are replaced with equal amounts of the compounds listed in the table below.

[0090]

[0091]

[0092]

[0093] This invention provides exemplary methods for synthesizing the above-mentioned compounds. For compounds in the following examples that do not have specific synthesis methods, they are also prepared by similar methods, requiring only the replacement of raw materials. These methods will not be elaborated here, or those skilled in the art can prepare them using other methods in the prior art.

[0094] Device embodiments

[0095] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0096] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0097] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof.

[0098] The light-emitting functional layer can be formed on the electrode by methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as the light-emitting functional layer can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0099] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0100] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives, wherein the aromatic amine derivatives include compounds shown below HT-1 to HT-50; or any combination thereof.

[0101]

[0102]

[0103]

[0104] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-50 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-50 doped with one or more compounds of HI-1 to HI-3 described below.

[0105]

[0106] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0107] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0108] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0109]

[0110] The electron transport region can be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region can also be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0111] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0112]

[0113]

[0114]

[0115]

[0116] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0117] Liq, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb.

[0118] The cathode is a mixture of magnesium and silver, LiF / Al, ITO and other metals, metal mixtures and oxides.

[0119] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0120] The above embodiments and comparative examples each provide an organic electroluminescent device, and the specific preparation methods are as follows:

[0121] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0122] The glass substrate with the ITO anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 Pa, on the aforementioned anode film, a 10 nm HT-4:HI-3 (97 / 3, w / w) mixture was vacuum thermally deposited as a hole injection layer; a 60 nm HT-4 compound was deposited as a hole transport layer; on top of the hole transport layer, a HT-47 compound was vacuum-deposited as an electron blocking layer material, with a total deposition thickness of 60 nm; a 40 nm host material: a RPD-8 (100:3, w / w) binary mixture was deposited as a light-emitting layer; on top of the light-emitting layer, a 5 nm ET-17 compound was vacuum-deposited as a hole blocking layer; a 25 nm ET-69:ET-57 (50 / 50, w / w) compound mixture was deposited as an electron transport layer; a 1 nm LiF compound was deposited as an electron injection layer; and a 150 nm aluminum compound was deposited as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0123] The device embodiments and comparative device embodiments of the present invention were completed according to the above preparation steps and testing methods. The specific structural formulas of the comparative compounds C1, C2, C3 and C4 used in the present invention are as follows:

[0124]

[0125] The specific methods for synthesizing compounds C1, C2, C3 and C4 were compared with those in patent documents KR1020120078301A, CN110313079A, CN103189469A and WO2015014434A1.

[0126] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0127] Under the same brightness, the driving voltage, current efficiency, and lifetime of the organic electroluminescent devices prepared in the examples and comparative examples were measured. Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 3000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT97 is as follows: using a luminance meter at 10000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 9700 cd / m² under the specified brightness. 2 The time is in hours.

[0128] Table 1 (To better demonstrate the performance advantages of this invention, the test data for Comparative Example 1 is set to 1, and the data in the table below are all ratios to it.)

[0129]

[0130]

[0131] Comparative Examples 2 and 3 used existing compounds C2 and C3, respectively. Because these two compounds lack electron-withdrawing groups in their molecular structures, electron injection and transport are hindered, resulting in a severe mismatch with hole transport. Therefore, their performance is poor when used as the main material in the OLED emissive layer. The biggest structural difference between the compound of this invention and the existing compound C1 used in Comparative Example 1 lies in the different 9-position substituent group of the carbazole. This invention uses an aromatic amine, while compound C1 uses an aryl group. Introducing an aromatic amine group into the compound of this invention can enhance the HOMO energy level of the material, significantly improving the injection performance and making the carrier transport more balanced, ultimately resulting in a significant improvement in the photoelectric performance of the material. Compared with the existing compound C4 used in Comparative Example 4, although C4 contains an aromatic amine structure, it lacks an indole structure. Device data shows that the introduction of the aromatic amine makes the voltage close to that of this invention, but the efficiency and lifetime are far inferior. The presumed reason is that this invention increases the rigidity and planarity of the compound by introducing an indole structure, allowing the hole transport to achieve carrier balance. C4 only has an aromatic amine structure, which is insufficient for hole transport, causing the luminescent recombination interface to be biased towards the electron blocking layer.

[0132] Although the invention has been described in conjunction with embodiments, the invention is not limited to the above embodiments. It should be understood that various modifications and improvements can be made by those skilled in the art under the guidance of the inventive concept, and the appended claims summarize the scope of the invention.

Claims

1. An organic compound having the structure shown in formula (1): In formula (1): X is selected from O or S; Y1 and Y2 are either single bonds or NR bonds, and one of Y1 and Y2 is a single bond and the other is an NR bond. The R has the structure shown in equation (a). L1 is selected from at least one of single bonds and C6-C18 aryl groups; Ar1 is selected from the following groups: unsubstituted or C6-C30 aryl substituted groups: Where "*" represents the linking site of the functional group; R1, R2 and R3 are each independently one of hydrogen, deuterium, halogen, cyano, C1-C30 chain alkyl, C1-C30 alkoxy, and C3-C30 cycloalkyl; In formula (a): L2 is selected from at least one of C6-C18 arylene and C3-C18 heteroarylene, wherein the heteroatom in the heteroarylene is N, S, or O; Ar2 and Ar3 are each independently selected from at least one of C6-C60 aryl groups and C3-C60 heteroaryl groups, wherein the heteroatoms in the heteroaryl group are N, S, or O.

2. The organic compound according to claim 1, having a structure as shown in formula (1-1) or formula (1-2): In equations (1-1) and (1-2), the definitions of X, L1, L2, Ar1, Ar2, Ar3, R1, R2, and R3 are the same as those in equation (1) or (a).

3. The organic compound according to claim 1 or 2, wherein in formula (1), formula (1-1), or formula (1-2), Ar1 is selected from the following groups: The asterisk (*) represents the linking site of a functional group.

4. The organic compound according to claim 1 or 2, wherein R1, R2 and R3 are hydrogen atoms.

5. The organic compound according to claim 1 or 2, wherein in formula I, Ar2 and Ar3 are each independently selected from the following groups: phenyl, naphthyl, anthracene, phenanthrene, indene, fluoranyl, triphenylene, pyrene, perylene, thionyl, tetraphenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, 9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentyl... One of the following: 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirofluorenyl, benzo[a]fluorenyl, furanyl, thiopheneyl, pyrroleyl, benzo[a]furanyl, benzo[a]thiopheneyl, isobenzo[a]furanyl, indolyl, dibenzo[a]furanyl, dibenzo[a]thiopheneyl, carbazoyl, acridineyl, isobenzo[a]furanyl, isobenzo[a]thiopheneyl, acridineyl, pyridyl, benzo[a]carbazoyl, azacarbazoyl, phenothiazinyl, and phenothiazinyl.

6. The organic compound according to claim 1, selected from any of the structures shown below: 。 7. An application of an organic compound according to any one of claims 1-6, wherein the application is as a functional material in an organic electronic device, said organic electronic device being selected from organic electroluminescent devices, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper; The organic compound is used as the host material for the light-emitting layer in organic electroluminescent devices.

8. An organic electroluminescent device, comprising a first electrode, a second electrode, and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer comprises a hole transport layer, a light-emitting layer, and an electron transport layer, and the light-emitting layer contains an organic compound as described in any one of claims 1-6.

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