Compounds and uses thereof

Abstract

The application discloses a compound and application thereof, and belongs to the technical field of display. A chemical structural formula of the compound is shown in the following formula: wherein Z1 and Z2 are independently O, S or Se; R1 and R2 are independently ; or one of R1 and R2 is ; Z3 to Z6 are independently N or CR4; the other of R1 and R2, R3 and R4 are independently hydrogen, deuterium, fluorine, cyano, C1-C10 alkyl, C1-C10 perfluoroalkyl, C1-C10 perfluoroalkoxy, C1-C10 perfluoroalkylthio, pentafluorothio, one of substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; and A is O, S, S=O, SO2 or Se. The compound has high charge transfer capacity and thermal stability, and an OLED device prepared based on the compound has low working voltage, high efficiency and long cycle life.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a compound and its applications. Background Technology

[0002] Organic light-emitting devices (OLEDs), also known as organic light-emitting diodes, have advantages such as self-illumination, low power consumption, wide viewing angle, light weight, thinness, fast response, high contrast, low driving voltage, and flexibility, and are widely used in the fields of displays and lighting.

[0003] Typically, an OLED device includes a cathode, an anode, and an electron transport layer, an emissive layer, and a hole transport layer stacked between the cathode and the anode. The hole transport layer is fabricated using a hole injection material.

[0004] Currently, there is still a need to improve the charge transfer capability and thermal stability of hole injection materials in order to further improve the voltage, efficiency and cycle life of OLED devices. Summary of the Invention

[0005] This invention provides a compound and its applications. Devices prepared using this compound exhibit lower operating voltage, higher efficiency, and longer cycle life. The technical solution is as follows: In a first aspect, a compound is provided, the chemical structural formula of which is shown below: ; Among them, Z1 and Z2 are each independently O, S or Se; Both R1 and R2 are ; Alternatively, one of R1 and R2 is The other of R1 and R2 is one of hydrogen, deuterium, fluorine, cyano, C1~C10 alkyl, C1~C10 perfluoroalkyl, C1~C10 perfluoroalkoxy, C1~C10 perfluoroalkylthio, pentafluorothio, substituted or unsubstituted C6~C30 aryl, or substituted or unsubstituted C3~C30 heteroaryl; Z3 to Z6 are each independently either N or CR4; R3 and R4 are each independently one of hydrogen, deuterium, fluorine, cyano, C1~C10 alkyl, C1~C10 perfluoroalkyl, C1~C10 perfluoroalkoxy, C1~C10 perfluoroalkylthio, pentafluorothio, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C3~C30 heteroaryl; A can be O, S, S=O, SO2, or Se.

[0006] In some possible implementations, the C1-C10 alkyl group is selected from C1-C4 alkyl groups; And / or, the C1-C10 perfluoroalkyl group is selected from C1-C7 perfluoroalkyl groups; And / or, the C1~C10 perfluoroalkoxy group is selected from C1~C7 perfluoroalkoxy groups; And / or, the C1~C10 perfluoroalkyl thio group is selected from the C1~C7 perfluoroalkyl thio group.

[0007] In some possible implementations, the C1-C4 alkyl group is one of methyl, ethyl, isopropyl, n-propyl, or tert-butyl.

[0008] In some possible implementations, the C1-C7 perfluoroalkyl group is one of -CF3, -C2F5, -C3F7, -C4F9, -C5F11, -C6F13, and -C7F15; The C1~C7 perfluoroalkoxy group is one of -OCF3, -OC2F5, -OC3F7, -OC4F9, -OC5F11, -OC6F13, and -OC7F15; The C1~C7 perfluoroalkylthio group is one of -SCF3, -SC2F5, -SC3F7, -SC4F9, -SC5F11, -SC6F13, and -SC7F15.

[0009] In some possible implementations, Z1 is either O or S, and Z2 is either O or S. Alternatively, both Z1 and Z2 are 0; Alternatively, both Z1 and Z2 are S.

[0010] In some possible implementations, R3 and R4 are each independently one of hydrogen, deuterium, cyano, trifluoromethyl, trifluoromethoxy, trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, 1-5 fluorinated phenyl, pyridyl, trifluoromethyl substituted pyridyl, 1-4 fluorinated substituted pyridyl, benzonitrile, or cyano substituted pyridyl.

[0011] In some possible implementations, when one of R1 and R2 is In this case, the other of R1 and R2 is one of hydrogen, deuterium, cyano, trifluoromethyl, trifluoromethoxy, trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, phenyl with 1-5 fluorine-substituted members, pyridyl, pyridyl with trifluoromethyl substituted members, pyridyl with 1-4 fluorine-substituted members, benzonitrile, pyridyl with cyano substituted members, biphenyl with fluorine-substituted members, biphenyl with trifluoromethyl substituted members, biphenyl with both fluorine and cyano substituted members, phenyl with both fluorine and trifluoromethyl substituted members, phenyl with both fluorine and trifluoromethyl substituted members, or pyridyl with both fluorine and trifluoromethyl substituted members.

[0012] In some possible implementations, Z3 through Z6 are all CR4; Alternatively, one of Z3 to Z6 is N, and the other three are CR4; Alternatively, two of Z3 to Z6 are N, and the other two are CR4.

[0013] In a second aspect, the invention provides the application of any of the compounds involved in the first aspect of the embodiments in organic electroluminescent devices, organic solar cells, organic thin-film transistors, organic photodetectors, organic field-effect transistors, organic integrated circuits, and organic photosensors.

[0014] Thirdly, a hole injection material is provided, the hole injection material comprising any of the compounds involved in the first aspect of the present invention.

[0015] In some possible implementations, the hole injection material further includes a hole transport compound, wherein the hole transport compound has a mass percentage of 70 wt% to 99.5 wt%. The hole transport compound is selected from at least one of carbazole compounds, triaromatic amine compounds, biphenyl diamine compounds, fluorene compounds, phthalocyanine compounds, polythiophene, polyethylene, polybenzene sulfonic acid, quinone compounds, and hexacyanohexatribenzene.

[0016] Fourthly, a charge generation layer material is provided, the charge generation layer material comprising any of the compounds involved in the first aspect of the present invention.

[0017] Fifthly, an organic electroluminescent device is provided, the organic electroluminescent device comprising: a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode; The light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer, wherein the hole transport functional layer includes any of the compounds involved in the first aspect of the present invention.

[0018] In some possible implementations, the light-emitting units are configured as multiple units, and a charge generation layer is provided between two adjacent light-emitting units. The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer. The P-type charge-generating layer includes any of the compounds involved in the first aspect of the embodiments of the present invention.

[0019] In some possible implementations, the hole transport functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, wherein the hole injection layer includes the compound.

[0020] In a sixth aspect, a display device is provided, the display device including the organic electroluminescent device according to the fifth aspect of the present invention.

[0021] This invention provides a compound whose thermal stability is effectively improved by introducing heterocyclic groups. Furthermore, the presence of a conjugated system in the compound is beneficial for enhancing its charge transfer capability. Additionally, the introduction of electron-withdrawing groups helps to regulate the LUMO energy level, improving hole injection and transport capabilities. Therefore, this compound exhibits high charge transfer capability and thermal stability, resulting in devices fabricated using this compound that have lower operating voltages, higher efficiency, and longer cycle life. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device provided in an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] In this article, "one or more" refers to any one, two or more of the listed items.

[0026] In this embodiment of the invention, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0027] In the embodiments of the present invention, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0028] In this embodiment of the invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Further, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Moreover, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0029] Unless otherwise specified, the percentage concentrations mentioned in the embodiments of this invention refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0030] Unless otherwise specified, the temperature parameters in the embodiments of the present invention can be either constant temperature treatment or treatment within a certain temperature range. The constant temperature treatment allows temperature fluctuations within the precision range controlled by the instrument. The room temperature in the embodiments of the present invention generally refers to 4℃~30℃, preferably 20±5℃.

[0031] There is still a need to improve the charge transfer capability and thermal stability of hole injection layer materials in current related technologies, so as to further improve the driving voltage, luminous efficiency and cycle life of OLED devices.

[0032] The first aspect of this invention provides a compound with the following chemical structural formula: .

[0033] Z1 and Z2 are each independently O, S or Se.

[0034] Both R1 and R2 are .

[0035] Alternatively, one of R1 and R2 is The other of R1 and R2 is one of hydrogen, deuterium, fluorine, cyano, C1~C10 alkyl, C1~C10 perfluoroalkyl, C1~C10 perfluoroalkoxy, C1~C10 perfluoroalkylthio, pentafluorothio, substituted or unsubstituted C6~C30 aryl, or substituted or unsubstituted C3~C30 heteroaryl.

[0036] Z3 to Z6 are each independently either N or CR4.

[0037] R3 and R4 are each independently one of hydrogen, deuterium, fluorine, cyano, C1-C10 alkyl, C1-C10 perfluoroalkyl, C1-C10 perfluoroalkoxy, C1-C10 perfluoroalkylthio, pentafluorothio, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl.

[0038] A can be O, S, S=O, SO2, or Se.

[0039] It should be noted that the "aryl" in the embodiments of this invention refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. This can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic rings, at least one must be an aromatic ring system. For example, "C6~C30 aryl" refers to an aryl group containing 6 to 30 carbon atoms. Each occurrence can be independently C6, C7, C8, C9, C10, C15, C20, C25, or C30 aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene oxide, and their derivatives. Understandably, multiple aryl groups can also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N, or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamine, and diaryl ether systems should also be included in the definition of aryl.

[0040] In the embodiments of this invention, "heteroaryl" refers to an aryl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, an O atom, an S atom, etc. For example, "C3~C30 heteroaryl" refers to a heteroaryl group containing 3 to 30 carbon atoms, and each occurrence can be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl, C8 heteroaryl, C9 heteroaryl, C10 heteroaryl, C11 heteroaryl, C12 heteroaryl, C14 heteroaryl, C18 heteroaryl, C20 heteroaryl, C25 heteroaryl, and C30 heteroaryl. Suitable examples include, but are not limited to: furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetraazole, indole, carbazole, pyrroloimidazole, pyrrolopyrrole, thienopyrrole, thienothiophene, furanolopyrrole, furanolofuran, thienofuran, benzoisoxazole, benzoisothiazolium, benzimazole, pyridine, pyrazine, pyrimidine, triazine, quinoline, isoquinoline, o-diazonyl, quinoxaline, phenanthridine, primidine, quinazoline, and quinazolineone. Understandably, "azaaryl" refers to a heteroaryl group whose non-carbon atom is an nitrogen atom.

[0041] Hydrogen includes isotopes with different numbers of neutrons, namely protium, deuterium, and tritium.

[0042] This invention provides a compound whose thermal stability is effectively improved by introducing heterocyclic groups. Furthermore, the presence of a conjugated system in the compound is beneficial for enhancing its charge transfer capability. Additionally, the introduction of electron-withdrawing groups helps to regulate the LUMO energy level, improving hole injection and transport capabilities. Therefore, this compound exhibits high charge transfer capability and thermal stability, resulting in devices fabricated using this compound that have lower operating voltages, higher efficiency, and longer cycle life.

[0043] In some examples, C1-C10 alkyl groups are selected from C1-C4 alkyl groups.

[0044] And / or, C1~C10 perfluoroalkyl groups are selected from C1~C7 perfluoroalkyl groups.

[0045] And / or, C1~C10 perfluoroalkoxy groups are selected from C1~C7 perfluoroalkoxy groups.

[0046] And / or, the C1~C10 perfluoroalkyl thio groups are selected from the C1~C7 perfluoroalkyl thio groups.

[0047] In some examples, the C1-C4 alkyl group is one of methyl, ethyl, n-propyl, isopropyl, or tert-butyl.

[0048] By limiting the C1 to C4 alkyl groups as described above, it is helpful to increase the degree of distortion of the compound and inhibit molecular stacking.

[0049] In some examples, the C1-C7 perfluoroalkyl group is one of -CF3, -C2F5, -C3F7, -C4F9, -C5F11, -C6F13, and -C7F15.

[0050] The C1~C7 perfluoroalkoxy group is one of -OCF3, -OC2F5, -OC3F7, -OC4F9, -OC5F11, -OC6F13, and -OC7F15.

[0051] The C1~C7 perfluoroalkylthio groups are one of -SCF3, -SC2F5, -SC3F7, -SC4F9, -SC5F11, -SC6F13, and -SC7F15.

[0052] C1-C7 perfluoroalkyl, C1-C7 perfluoroalkoxy, and C1-C7 perfluoroalkylthio are all electron-withdrawing groups. Introducing these electron-withdrawing groups can help regulate the LUMO energy level of the compound, improve hole injection and transport capabilities, and enable the fabricated device to have lower operating voltage, higher efficiency, and longer cycle life.

[0053] In some examples, Z1 is either O or S, and Z2 is either O or S.

[0054] Alternatively, both Z1 and Z2 can be O.

[0055] Alternatively, both Z1 and Z2 are S.

[0056] Both O and S are electron-withdrawing groups. When one of Z1 and Z2 is O and the other is S, it helps to increase the electron affinity and regulate the LUMO energy level of the compound, which is beneficial for improving the hole injection and transport capabilities.

[0057] Furthermore, O has high electronegativity. When both Z1 and Z2 are O, it helps to significantly reduce the LUMO energy level of the compound, enhance electron affinity, improve hole injection and transport capabilities, and endow the device with lower operating voltage, higher current efficiency, and longer lifetime. S has a larger atomic radius and better orbital overlap. When both Z1 and Z2 are S, it helps to improve the charge transfer capability of the compound, thereby improving the doping efficiency of the compound and endowing the device with lower operating voltage, higher current efficiency, and longer lifetime.

[0058] In some examples, R3 and R4 are each independently one of hydrogen, deuterium, cyano, trifluoromethyl, trifluoromethoxy, trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, 1-5 fluorinated phenyl, pyridyl, trifluoromethyl substituted pyridyl, 1-4 fluorinated substituted pyridyl, benzonitrile, or cyano substituted pyridyl.

[0059] In this compound, the two trifluoromethyl groups in the di(trifluoromethyl)phenyl group can be in the para or meta position. The trifluoromethyl-substituted pyridyl group can be 2-trifluoromethylpyridine, 3-trifluoromethylpyridine, or 4-trifluoromethylpyridine.

[0060] A phenyl group with 1-5 fluorine substitutions refers to a phenyl group that can have 1, 2, 3, 4, or 5 fluorine substitutions. When there are multiple fluorine substitutions, the substitution positions can be varied and are not specifically limited. For example, if a phenyl group has 2 fluorine substitutions, these 2 fluorines can be ortho, meta, or para.

[0061] The 1-4 fluorinated pyridinium group refers to the pyridinium group having 1, 2, 3, or 4 fluorinated substitutions. When there are multiple fluorinated substitutions, the substitution positions can also be varied, and no specific limitation is made.

[0062] Most of the R3 and R4 groups mentioned above are strong electron-withdrawing groups. Introducing these strong electron-withdrawing groups helps to increase the electron affinity of the molecule, which is conducive to complete charge transfer between the compound and the hole transport compound, giving the device a lower operating voltage, higher current efficiency and longer lifespan.

[0063] In some examples, when one of R1 and R2 is In this case, the other of R1 and R2 is one of hydrogen, deuterium, cyano, trifluoromethyl, trifluoromethoxy, trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, phenyl with 1-5 fluorine-substituted members, pyridyl, pyridyl with trifluoromethyl substituted members, pyridyl with 1-4 fluorine-substituted members, benzonitrile, pyridyl with cyano substituted members, biphenyl with fluorine-substituted members, biphenyl with trifluoromethyl substituted members, biphenyl with both fluorine and cyano substituted members, phenyl with both fluorine and trifluoromethyl substituted members, phenyl with both fluorine and trifluoromethyl substituted members, or pyridyl with both fluorine and trifluoromethyl substituted members.

[0064] Most of the above-mentioned groups are electron-withdrawing groups. By limiting the other one of R1 and R2 as described above, it helps to increase the electron affinity of the compound, which is conducive to complete charge transfer between the compound and the hole transport compound. Furthermore, the steric hindrance can be used to increase the molecular twist, thereby giving the device a lower operating voltage, higher current efficiency and longer lifespan.

[0065] In some examples, Z3 through Z6 are all CR4.

[0066] Alternatively, one of Z3 to Z6 is N, and the other three are CR4.

[0067] Alternatively, two of Z3 to Z6 are N, and the other two are CR4.

[0068] When Z3 to Z6 are all CR4, the stability of the conjugated system can be maximized, improving the doping efficiency of the compound. When one of Z3 to Z6 is N and the other three are CR4, the LUMO energy level of the compound can be appropriately reduced, achieving a higher doping efficiency. When two of Z3 to Z6 are N and the other two are CR4, the electron-withdrawing ability can be significantly enhanced, the LUMO energy level of the compound can be greatly reduced, and an even higher doping efficiency can be achieved.

[0069] It should be noted that when Z3 to Z6 are all CR4, or three of Z3 to Z6 are CR4, or two of Z3 to Z6 are CR4, the R4 corresponding to different groups can be the same or different. For example, when Z3 to Z6 are all CR4, the R4 in Z3, Z5, and Z6 is H, and the R4 in Z4 is CF3.

[0070] Regarding the compounds mentioned above, some examples of these compounds are listed below, see compounds 1-192.

[0071]

[0072] Secondly, embodiments of the present invention provide the application of any of the above-mentioned compounds in organic electroluminescent devices, organic solar cells, organic thin-film transistors, organic photodetectors, organic field-effect transistors, organic integrated circuits, or organic photoreceptors.

[0073] Thirdly, embodiments of the present invention provide a hole injection material, which includes any of the compounds involved in the first aspect described above.

[0074] The hole injection material provided in this embodiment of the invention has all the advantages of the compounds involved in this embodiment of the invention.

[0075] The hole injection material provided in this embodiment of the invention, when applied to organic electroluminescent devices, can be used to prepare the hole injection layer of the organic electroluminescent device, so that the organic electroluminescent device has both high luminous efficiency, low operating voltage and strong thermal stability.

[0076] In some examples, the mass percentage of any compound involved in the first aspect of the present invention in the hole injection material is 0.05wt% to 99.95wt%, which includes, but is not limited to, the range consisting of one or any two of the following values: 0.05%, 1%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 29%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 69%, 70%, 72%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 96%, 98%, 99%, 99.95%, etc. Optionally, the mass percentage of any compound involved in the first aspect of the present invention in the hole injection material is 0.5wt% to 30wt%.

[0077] In other examples, the hole injection material provided in the embodiments of the present invention includes any of the compounds involved in the first aspect and a hole transport compound, wherein the mass percentage of the hole transport compound is 70wt% to 99.5wt%, which includes, but is not limited to, a range consisting of one or any two of the following values: 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 96%, 98%, 99%, 99.95%, etc.

[0078] Furthermore, for this type of hole injection material, the mass percentage of any compound involved in the first aspect is 0.5wt% to 30wt%, and the mass percentage of the hole transport compound is 70wt% to 99.5wt%.

[0079] Some suitable hole transport compounds are selected from at least one of carbazole compounds, triaromatic amine compounds, benzidine diamine compounds, fluorene compounds, phthalocyanine compounds, polythiophene, polyethylene, polybenzenesulfonic acid, quinone compounds, and hexacyanohexatribenzene.

[0080] For example, the hole transport compound can be any of the following compounds. Furthermore, the materials involved in the hole transport layer and the electron blocking layer can also be any of the following compounds.

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] .

[0087] In some examples, the hole transport compound may also be any of the following compounds.

[0088]

[0089] The aforementioned hole transport compound can form a charge transfer complex with any of the compounds involved in the first aspect of the present invention to generate and transport holes, thereby enhancing the hole injection and transport capabilities of the hole injection material, thereby reducing the operating voltage of the device, improving the luminous efficiency of the device, and extending the lifespan of the device.

[0090] Fourthly, embodiments of the present invention provide a charge generation layer material, which includes any of the compounds involved in the first aspect of the present invention.

[0091] The charge generation layer material provided in this embodiment of the invention possesses all the advantages of the compounds involved in this embodiment. Specifically, it facilitates hole injection into the upper light-emitting unit, achieving charge balance in the stacked device.

[0092] In some examples, the mass percentage of any compound involved in the first aspect of the present invention in the charge generation layer material is 100 wt%.

[0093] In other examples, in addition to any of the compounds involved in the first aspect of the embodiments of the present invention, the charge generation layer material also includes other compounds. The embodiments of the present invention do not specifically limit the compounds, and they can be selected adaptively according to actual needs.

[0094] Fifthly, embodiments of the present invention provide an organic electroluminescent device, which includes: a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode.

[0095] The light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer. The hole transport functional layer includes the compound involved in the first aspect of the present invention.

[0096] Specifically, the hole transport functional layer includes the hole injection material involved in the third aspect of the present invention, which includes the compound involved in the first aspect of the present invention and the hole transport compound involved in the third aspect of the present invention.

[0097] The organic electroluminescent device provided in this embodiment of the invention possesses all the advantages of the compounds involved in this embodiment. For example, the organic electroluminescent device combines high luminous efficiency, low operating voltage, and long lifespan.

[0098] In some examples, multiple light-emitting units are provided, and a charge generation layer is provided between two adjacent light-emitting units. The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer; the P-type charge generation layer includes the compound involved in the first aspect of the embodiments of the present invention.

[0099] When there is one light-emitting unit, the organic electroluminescent device is a single-layer device. When there are multiple light-emitting units, the organic electroluminescent device is a multilayer device. Each light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer.

[0100] In some examples, the hole transport functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, wherein the hole injection layer includes the compound involved in the first aspect of the present invention.

[0101] Specifically, the hole injection layer includes a hole injection material, which includes the compound involved in the first aspect of the present invention and the hole transport compound involved in the third aspect of the present invention.

[0102] It should be noted that in OLED devices, p-type doping technology is often used to achieve efficient charge injection and transport. This involves introducing molecular acceptors with high electron affinity into the hole injection layer to promote the transfer of electrons from the hole transport compound to the dopant, thereby forming mobile holes. This significantly improves the material's conductivity and reduces the interface injection barrier. The appropriate use of p-type dopant compounds can greatly improve device performance and extend device lifetime. The compound involved in the first aspect of this invention is used as a p-type dopant compound in the hole injection layer.

[0103] The following example illustrates the concept of a single light-emitting unit and a single-layer organic electroluminescent device.

[0104] As an example, the hole transport functional layer includes a hole injection layer and a hole transport layer, wherein the anode, hole injection layer, hole transport layer, light emission layer, and electron transport functional layer are stacked in sequence.

[0105] As another example, the hole transport functional layer includes a hole transport layer and an electron blocking layer, wherein the anode, hole transport layer, electron blocking layer and light-emitting layer are stacked in sequence.

[0106] As another example, the hole transport functional layer includes a hole transport layer, an electron blocking layer, and a hole injection layer, wherein the anode, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, and electron transport functional layer are stacked in sequence.

[0107] In some examples, the electron transport functional layer includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer.

[0108] The following example uses an organic electroluminescent device as a single-layer device.

[0109] As an example, the electron transport functional layer includes an electron transport layer, wherein the cathode, electron transport layer, light-emitting layer, and hole transport functional layer are stacked in sequence.

[0110] As another example, the electron transport functional layer includes an electron transport layer and an electron injection layer, wherein the cathode, electron injection layer, electron transport layer, light-emitting layer, and hole transport functional layer are stacked in sequence.

[0111] As another example, the electron transport functional layer includes an electron transport layer and a hole blocking layer, wherein the cathode, electron transport layer, hole blocking layer, light-emitting layer, and hole transport functional layer are stacked in sequence.

[0112] As another example, the electron transport functional layer includes an electron transport layer, a hole blocking layer, and an electron injection layer, wherein the cathode, electron injection layer, electron transport layer, hole blocking layer, light-emitting layer, and hole transport functional layer are stacked in sequence.

[0113] When multiple light-emitting units are configured and the organic electroluminescent device is a stacked device, for example, the organic electroluminescent device includes two light-emitting units, and a charge generation layer is provided between the two light-emitting units. The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer. That is, the organic electroluminescent device includes: a first electrode, a first light-emitting unit, an N-type charge generation layer, a P-type charge generation layer, a second light-emitting unit, and a second electrode.

[0114] The first light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer. The second light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer. The specific details have been introduced earlier and will not be repeated here.

[0115] For any of the organic electroluminescent devices mentioned above, the total thickness of at least one light-emitting unit located between the first electrode and the second electrode can be 1nm-1000nm, including but not limited to any of the following values ​​or a range consisting of any two values: 1nm, 30nm, 50nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 550nm, 600nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm, 1000nm, etc.

[0116] Furthermore, the total thickness of the at least one light-emitting unit can be 50nm-500nm, including but not limited to any of the following values ​​or a range consisting of any two values: 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, and 500nm.

[0117] In some embodiments of the present invention, the preparation method for each functional layer of the light-emitting unit of the organic electroluminescent device includes: vacuum evaporation, molecular beam evaporation, solvent-based dip coating, spin coating, bar coating, or inkjet printing.

[0118] It should be noted that the organic layers in the organic electroluminescent devices involved in the embodiments of the present invention can be prepared by vacuum evaporation, molecular beam evaporation, solvent-based dip coating, spin coating, rod coating, or inkjet printing. Metal electrodes can be prepared by evaporation or sputtering.

[0119] In a sixth aspect, embodiments of the present invention also provide a display device, which includes the organic electroluminescent device provided in the fifth aspect of embodiments of the present invention.

[0120] The display device provided in this embodiment of the invention uses the organic electroluminescent device mentioned above, which helps to reduce power consumption and extend its lifespan.

[0121] For example, the display device may be a mobile phone, tablet, laptop, MP3 player, wearable device, television, electronic screen, vehicle display, special display device, etc.

[0122] The specific embodiments of the present invention will now be described in more detail. While specific embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0123] It should be noted that the serial numbers of the compounds provided in the following embodiments are the same as the compounds with the same serial numbers among the aforementioned compounds 1-192.

[0124] The following examples involve the synthesis of compounds, including intermediate compounds (hereinafter referred to as intermediates). These compounds and intermediates were separated by column chromatography and characterized by elemental analysis and high-resolution mass spectrometry (1HRMS).

[0125] Example 1 Example 1 provides compound 2, and the synthetic route and method are shown below:

[0126] Step 1: Synthesis of intermediate 2-1 Intermediate 2-bromo-8-(trifluoromethyl)dibenzo[b,d]furan (50.00 g, 159 mmol), pinacol diboronate (48.25 g, 190 mmol), and dried potassium acetate (23.41 g, 238 mmol) were dissolved in 500 mL of dried toluene and added to a three-necked flask. Then, under N2 protection, 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride (2.33 g, 3.18 mmol) was added to the reaction mixture, and the mixture was heated to reflux and stirred for 4 h. After the reaction was complete, the mixture was cooled to room temperature. Extraction and washing were performed using dichloromethane and a saturated sodium chloride aqueous solution, and the organic phase was dried over sodium sulfate. The mixture was filtered, the solvent was concentrated to dryness, and the crude product was purified by column chromatography (ethyl acetate to n-hexane, volume ratio = 1:1) to obtain the target compound 2-1 (36.56 g, yield 63.5%).

[0127] Step 2: Synthesis of intermediate 2-2 4,8-Dibromobenzo[1,2-D:4,5-D']bis(oxazole) (14.31 g, 45 mmol), 2-2 (35.85 g, 99 mmol), and potassium phosphate (19.10 g, 90 mmol) were dissolved in a toluene:water mixture of 70 mL:14 mL and added to a three-necked flask. Under N2 protection, palladium acetate (0.20 g, 0.9 mmol) and SPhos (0.74 g, 1.8 mmol) were added to the reaction mixture, and the mixture was heated to reflux and stirred for 8 h. After the reaction was complete, the mixture was cooled to room temperature. The mixture was extracted and washed with dichloromethane and a saturated sodium chloride aqueous solution, and then the organic phase was dried over sodium sulfate. The mixture was filtered, the solvent was concentrated to dryness, and the crude product was purified by column chromatography (ethyl acetate to n-hexane, volume ratio = 1:3) to obtain the target compound 2-2 (17.02 g, yield 60.2%).

[0128] Step 3: Synthesis of intermediates 2-3 Intermediate 2-2 (15.71 g, 25 mmol) was dissolved in 60 mL of ultra-dry tetrahydrofuran under nitrogen protection and added to a three-necked flask. The reaction mixture was then cooled to [temperature missing]. At 20°C, 55 mL of bis(trimethylsilyl)aminolithium (1.0 M, dissolved in tetrahydrofuran) was added dropwise, and the reaction was continued at this temperature for 2 h. Then, elemental iodine (12.69 g, 50 mmol) was added, and the reaction was continued at room temperature for 0.5 h. After the reaction was completed, the mixture was quenched with saturated sodium sulfite solution, extracted with an appropriate amount of ethyl acetate, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (ethyl acetate to n-hexane volume ratio = 1:5) to obtain intermediate 2-3 (17.60 g, yield 80.0%).

[0129] Step 4: Synthesis of intermediates 2-4 Intermediate 2-3 (15.84 g, 18 mmol), malononitrile (4.76 g, 72 mmol), and potassium carbonate (14.93 g, 108 mmol) were dissolved in 80 mL of N,N-dimethylformamide and added to a three-necked flask. Tetra(triphenylphosphine)palladium (0.83 g, 0.72 mmol) was then added to the reaction mixture under N2 protection, and the mixture was heated to 80 °C and stirred overnight. After the reaction was complete, the mixture was cooled to room temperature. Dilute hydrochloric acid was slowly added dropwise in an ice-water bath until a large amount of solid precipitated. The crude product was filtered and further purified by recrystallization to obtain the target compound 2-4 (7.12 g, yield 52.3%).

[0130] Step 5: Synthesis of Compound 2 Intermediate 2-4 (6.82 g, 9 mmol) was dissolved in 15 mL of dichloromethane solution, and then bis(trifluoroacetoxy)iodobenzene (PIFA, 7.74 g, 18 mmol) was added in portions under N2 protection. The reaction was carried out at room temperature for 48 h. After the reaction was completed, the reaction solution was concentrated to an appropriate amount of solvent, and a large amount of solid precipitated out. The solid was filtered to obtain target compound 2 (5.19 g, yield 76.42%).

[0131] Example 2 Example 2 provides compound 4, and the synthetic route and method are shown below:

[0132] Step 1: Synthesis of intermediate 4-1 The synthesis method of intermediate 4-1 is the same as that of intermediate 2-1, with a yield of 70%.

[0133] Step 2: Synthesis of intermediate 4-2 The synthesis method of intermediate 4-2 is the same as that of intermediate 2-2, with a yield of 68%.

[0134] Step 3: Synthesis of intermediate 4-3 The synthesis method of intermediate 4-3 is the same as that of intermediate 2-3, with a yield of 70%.

[0135] Step 4: Synthesis of intermediate 4-4 The synthesis method of intermediate 4-4 is the same as that of intermediate 2-4, with a yield of 78%.

[0136] Step 5: Synthesis of Compound 4 The synthesis method of compound 4 is the same as that of compound 2, with a yield of 46%.

[0137] Example 3 Example 3 provides compound 46, the synthetic route and method of which are shown below:

[0138] Step 1: Synthesis of Intermediate 46-1 2,8-Dibromodibenzofuran (50 g, 153 mmol), pentafluorophenylboronic acid (35.66 g, 168 mmol), tetrakis(triphenylphosphine)palladium (5.30 g, 4.56 mmol), and potassium phosphate (64.95 g, 306 mmol) were dissolved in a toluene:ethanol:water mixture of 250 mL:50 mL:50 mL and added to a three-necked flask. The reaction mixture was heated to reflux under N2 protection and stirred for 4 h. After the reaction was complete, the mixture was cooled to room temperature. The mixture was extracted and washed with dichloromethane and a saturated sodium chloride aqueous solution, and then the organic phase was dried over sodium sulfate. The mixture was filtered, the solvent was concentrated to dryness, and the crude product was purified by column chromatography (ethyl acetate to n-hexane, volume ratio = 1:10) to obtain the target compound 46-1 (38.05 g, yield 60.2%).

[0139] Step 2: Synthesis of intermediate 46-2 The synthesis method of intermediate 46-2 is the same as that of intermediate 2-1, with a yield of 63%.

[0140] Step 3: Synthesis of intermediate 46-3 The synthesis method of intermediate 46-3 is the same as that of intermediate 2-2, with a yield of 65%.

[0141] Step 3: Synthesis of intermediate 46-4 The synthesis method of intermediate 46-4 is the same as that of intermediate 2-3, with a yield of 80%.

[0142] Step 4: Synthesis of intermediate 46-5 The synthesis method of intermediate 46-5 is the same as that of intermediate 2-4, with a yield of 50%.

[0143] Step 5: Synthesis of Compound 46 The synthesis method of compound 46 is the same as that of compound 2, with a yield of 82%.

[0144] Example 4 Example 4 provides compound 51, the synthetic route and method of which are shown below:

[0145] Step 1: Synthesis of intermediate 51-1 The synthesis method of compound 51-1 is the same as that of intermediate 46-1, with a yield of 70%.

[0146] Step 2: Synthesis of intermediate 51-2 The synthesis method of compound 51-2 is the same as that of intermediate 2-1, with a yield of 68%.

[0147] Step 3: Synthesis of intermediate 51-3 The synthesis method of compound 51-3 is described in intermediate 2-2, with a yield of 70%.

[0148] Step 4: Synthesis of intermediate 51-4 The synthesis method of compound 51-4 is described in intermediate 2-3, with a yield of 78%.

[0149] Step 5: Synthesis of intermediate 51-5 The synthesis method of compound 51-5 is described in intermediate 2-4, with a yield of 46%.

[0150] Step 6: Synthesis of Compound 51 The synthesis method of compound 51 is the same as that of compound 2, with a yield of 78%.

[0151] Example 5 Example 5 provides compound 56, the synthetic route and method of which are shown below:

[0152] Step 1: Synthesis of intermediate 56-1 The synthesis method of intermediate 56-1 is the same as that of intermediate 46-1, with a yield of 67%.

[0153] Step 2: Synthesis of intermediate 56-2 The synthesis method of intermediate 56-2 is the same as that of intermediate 2-1, with a yield of 60%.

[0154] Step 3: Synthesis of intermediate 56-3 The synthesis method of intermediate 56-3 is the same as that of intermediate 2-2, with a yield of 68%.

[0155] Step 4: Synthesis of intermediate 56-4 The synthesis method of intermediate 56-4 is the same as that of intermediate 2-3, with a yield of 70%.

[0156] Step 5: Synthesis of intermediate 56-5 The synthesis method of intermediate 56-5 is the same as that of intermediate 2-4, with a yield of 40%.

[0157] Step 6: Synthesis of Compound 56 The synthesis method of compound 56 is the same as that of compound 2, with a yield of 75%.

[0158] Example 6 Example 6 provides compound 58, the synthetic route and method of which are shown below:

[0159] Step 1: Synthesis of intermediate 58-1 The synthesis method of intermediate 58-1 is the same as that of intermediate 2-2, with a yield of 65%.

[0160] Step 2: Synthesis of intermediate 58-2 The synthesis method of intermediate 58-2 is the same as that of intermediate 2-3, with a yield of 72%.

[0161] Step 3: Synthesis of intermediate 58-3 The synthesis method of intermediate 58-3 is the same as that of intermediate 2-4, with a yield of 43%.

[0162] Step 4: Synthesis of Compound 58 The synthesis method of compound 58 is the same as that of compound 2, with a yield of 70%.

[0163] Example 7 Example 7 provides compound 73, the synthetic route and method of which are shown below:

[0164] Step 1: Synthesis of intermediate 73-1 The synthesis method of intermediate 73-1 is the same as that of intermediate 2-2, with a yield of 72%.

[0165] Step 2: Synthesis of intermediate 73-2 The synthesis method of intermediate 73-2 is the same as that of intermediate 2-3, with a yield of 78%.

[0166] Step 3: Synthesis of intermediate 73-3 The synthesis method of intermediate 73-3 is the same as that of intermediate 2-4, with a yield of 46%.

[0167] Step 4: Synthesis of Compound 73 The synthesis method of compound 73 is the same as that of compound 2, with a yield of 67%.

[0168] Example 8 Example 8 provides compound 163, the synthetic route and method of which are shown below:

[0169] Step 1: Synthesis of intermediate 163-1 4,8-Dibromobenzo[1,2-D:4,5-D']bis(oxazole) (5.5 g, 17.3 mmol), ditrifluoromethylbiphenylboronic acid (6.36 g, 19.03 mmol), and potassium carbonate (14.35 g, 103.8 mmol) were dissolved in a toluene:water mixture of 275 mL:55 mL and added to a three-necked flask. Then, under N2 protection, tetrakis(triphenylphosphine)palladium (0.60 g, 0.52 mmol) and XPhos (0.25 g, 0.52 mmol) were added to the reaction mixture, and the mixture was heated to reflux and stirred for 8 h. After the reaction was complete, the mixture was cooled to room temperature. The mixture was then extracted and washed with dichloromethane and a saturated sodium chloride aqueous solution, and the organic phase was dried over sodium sulfate. The solvent was concentrated to dryness by filtration, and the crude product was purified by column chromatography (ethyl acetate and n-hexane volume ratio = 1:2) to obtain the target compound 163-1 (5.62 g, yield 61.6%).

[0170] Step 2: Synthesis of intermediate 163-2 The synthesis method of intermediate 163-2 is the same as that of intermediate 163-1, with a yield of 70%.

[0171] Step 3: Synthesis of intermediate 163-3 The synthesis method of intermediate 163-3 is the same as that of intermediate 2-3, with a yield of 75%.

[0172] Step 4: Synthesis of intermediate 163-4 The synthesis method of intermediate 163-4 is the same as that of intermediate 2-4, with a yield of 50%.

[0173] Step 4: Synthesis of Compound 163 The synthesis method of compound 163 is the same as that of compound 2, with a yield of 65%.

[0174] The calculated and measured MS-FAB values ​​of the compounds provided in Examples 1-8 and the intermediates in the synthesis process are shown in Table 1.

[0175]

[0176] The calculated and measured values ​​of the elemental analysis of the compounds provided in Examples 1-7 are shown in Table 2.

[0177]

[0178] Application Examples The following examples, Application Examples 1-8 and Comparative Examples 1-3, further illustrate the application effects of the compounds provided in the above examples in OLED devices. The OLED devices involved in Application Examples 1-8 and Comparative Examples 1-3 are manufactured using the same process, the same substrate material and electrode material, and the same electrode film thickness. The difference lies in the hole injection layer of the different OLED devices.

[0179] See Figure 1 The OLED device comprises a glass substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, an electron blocking layer 150, a light-emitting layer 160, a hole blocking layer 170, an electron transport layer 180, an electron injection layer 190, a cathode 200, and a light extraction layer 210, arranged in sequence. The specific structure is: glass / anode (ITO) / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / light-emitting layer (EML, main material: blue luminescent material) / hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) / cathode / light extraction layer (CPL).

[0180] The fabrication method of the OLED device corresponding to Application Example 1 is as follows: The transparent conductive ITO glass substrate (with an anode) (China Southern Glass Group Co., Ltd.) was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, and then sequentially washed with ethanol, acetone, and deionized water. It was then baked in a clean environment until all moisture was removed, cleaned with ultraviolet photosynthetic ozone, and treated with oxygen plasma for 30 seconds. The anode-bearing glass substrate was then placed in a vacuum chamber and evacuated.

[0181] Hole injection layer: Compound HT: Compound 2 (mass ratio of 97:3, thickness of 10nm) was deposited on ITO as a hole injection layer at a deposition rate of 0.1nm / s.

[0182] Hole transport layer: Compound HT is deposited on the hole injection layer to form a 120 nm thick hole transport layer at a deposition rate of 0.1 nm / s.

[0183] Electron blocking layer: Compound EB is deposited on the surface of the hole transport layer to form a 10 nm thick electron blocking layer at a deposition rate of 0.1 nm / s.

[0184] Emitting layer: A 20nm thick emitting layer is deposited on the electron blocking layer. The emitting layer includes compound BH and guest material BD. BH is the host emitting material and BD is the phosphorescent dopant guest material with a doping mass percentage of 2% and a deposition rate of 0.1nm / s.

[0185] Hole blocking layer: Compound HB is deposited on the surface of the light-emitting layer to form a 5nm thick hole blocking layer at a deposition rate of 0.1nm / s.

[0186] Electron transport layer: A 30 nm thick layer of compounds ET and LiQ (weight ratio 5:5) was deposited on the surface of the hole blocking layer as an electron transport layer. LiQ is lithium 8-hydroxyquinoline, and the deposition rate was 0.1 nm / s.

[0187] Electron injection layer: A 1 nm thick LiQ layer is deposited on the surface of the electron transport layer as the electron injection layer.

[0188] Cathode: A cathode with a thickness of 15 nm was fabricated on the surface of the electron injection layer. The cathode was made of Mg and Ag with a mass ratio of 1:9.

[0189] Optical extraction layer: An 80nm thick CPL is deposited on the cathode surface as an optical extraction layer.

[0190] The partial composition of the OLED devices prepared in Application Examples 2-8 and Comparative Examples 1-3 can be found in Table 3 below.

[0191]

[0192] The raw material compounds involved in the fabrication of the aforementioned OLED devices are shown below:

[0193]

[0194]

[0195]

[0196] .

[0197] The performance of each OLED device listed in Table 3 was tested. During the testing process, a known driving circuit was used to connect the anode and cathode. The test items are shown below: Using a Photo Research PR655 spectrometer, at 1000 cd / cm 2 Under certain brightness conditions, the driving voltage, turn-on voltage @1 nit, current efficiency, and color coordinates (CIEy) of each device were tested.

[0198] The room temperature and high temperature lifetimes of each device were tested using a Jinghe D3000-96CH lifetime meter under the following conditions: 20 mA / cm². 2 The time (LT95) for the brightness to return to 95% of its initial brightness under current density in both ambient (27°C) and high (85°C) environments is the unit of device lifetime, expressed in Hr.

[0199] The relevant test data are shown in Table 4.

[0200]

[0201] As shown in Table 4, when the hole injection layer was prepared using the compounds provided in the embodiments of the present invention, the driving voltage of the OLED device was controlled between 3.40V and 3.60V, all lower than the upper limit of 3.60V. In contrast, the driving voltage of Comparative Examples 1-3 was as high as 3.70V to 3.90V, which was significantly higher.

[0202] When the hole injection layer was prepared using the compounds provided in the embodiments of the present invention, the turn-on voltage of the OLED devices was generally between 2.65V and 2.80V, while the turn-on voltage of Comparative Examples 1-3 was between 2.95V and 3.10V. This result indicates that the compounds used in the present invention can effectively reduce the turn-on voltage and driving voltage of the devices, thereby significantly improving the energy efficiency of the devices and reducing power consumption.

[0203] Furthermore, when the hole injection layer was prepared using the compounds provided in the embodiments of the present invention, the current efficiency of the OLED devices was consistently in the range of 220 cd / A to 241 cd / A, significantly higher than the current efficiencies of 190 cd / A to 210 cd / A in Comparative Examples 1-3. This result demonstrates that the compounds used in this invention can significantly improve the luminous efficiency of the device, making the energy conversion process more efficient and suitable for display and lighting applications requiring high brightness and low power consumption.

[0204] Furthermore, when the hole injection layer was prepared using the compounds provided in the embodiments of the present invention, the room temperature lifetime (LT95) of the OLED devices was greater than or equal to 220 hours, with most exceeding 240 hours and reaching a maximum of 260 hours. In contrast, the room temperature lifetime of Comparative Examples 1-3 was only 150 to 180 hours.

[0205] When the hole injection layer was prepared using the compounds provided in the embodiments of this invention at a high temperature of 85°C, the high-temperature lifetime of the OLED devices was greater than or equal to 160 hours, with most devices having a lifetime between 170 and 190 hours. In contrast, the lifetimes of Comparative Examples 1-3 were only 115 to 130 hours, showing a significant difference. These results demonstrate that the compounds used in this invention significantly improve the thermal stability and long-term operational reliability of the devices, especially under high-temperature operating conditions, where their advantages are even more pronounced.

[0206] The compounds provided in this invention exhibit excellent performance in OLED devices. In particular, derivatives with substituents introduced at the ortho position of the single bond in dibenzofuran (compounds 51, 56, and 58) demonstrate superior performance compared to those with other substitutions. The introduction of substituents significantly increases the twisting between the dibenzofuran group and the central conjugated bisoxazole ring, which helps suppress intermolecular interactions (e.g., charge transfer in the ground state) in the central conjugated system, improving the doping efficiency of the p-dopant and enhancing device performance. Furthermore, compound 58 directly introduces an electron-withdrawing group onto the benzene ring connecting the dibenzofuran and bisoxazole ring, which to some extent enhances the electron affinity of the molecule, facilitating complete charge transfer between the p-dopant dopant and the HT material. Additionally, the asymmetricly substituted compound 163 also exhibits relatively good device performance. We attribute this to the fact that asymmetric substitution allows for fine-tuning of compound properties through the introduction of different substituents, making the designed molecule more suitable for device requirements (e.g., sublimation efficiency, energy level matching).

[0207] In summary, the compounds used in the embodiments of this invention improve the device voltage, device efficiency, and device lifetime of organic electroluminescent devices when preparing hole injection layers. These performance improvements are attributed to the compounds possessing suitable LUMO energy levels and high electron mobility, as well as the effective doping and molecular structure distortion that suppresses film crystallinity.

[0208] The above description is merely for the purpose of enabling those skilled in the art to understand the technical solutions of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compound, characterized in that, The chemical structural formula of the compound is shown below: ； Among them, Z1 and Z2 are each independently O, S or Se; Both R1 and R2 are ; Alternatively, one of R1 and R2 is The other of R1 and R2 is an unsubstituted C6~C30 aryl group; Alternatively, one of R1 and R2 is The other one of R1 and R2 is trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, phenyl with 1-5 fluorine-substituted groups, benzonitrile, fluorine-substituted biphenyl, trifluoromethyl-substituted biphenyl, biphenyl with both fluorine and cyano groups substituted, and phenyl with both fluorine and trifluoromethyl groups substituted. Z3 to Z6 are all CR4; R3 is hydrogen, and R4 is one of hydrogen, deuterium, fluorine, cyano, C1~C10 alkyl, C1~C10 perfluoroalkyl, C1~C10 perfluoroalkoxy, C1~C10 perfluoroalkylthio, pentafluorothio, unsubstituted C6~C30 aryl, or unsubstituted C3~C30 heteroaryl. A can be O, S, S=O, SO2, or Se.

2. The compound according to claim 1, characterized in that, The C1-C10 alkyl group is selected from C1-C4 alkyl group; And / or, the C1-C10 perfluoroalkyl group is selected from C1-C7 perfluoroalkyl groups; And / or, the C1~C10 perfluoroalkoxy group is selected from C1~C7 perfluoroalkoxy groups; And / or, the C1~C10 perfluoroalkyl thio group is selected from the C1~C7 perfluoroalkyl thio group.

3. The compound according to claim 2, characterized in that, The C1-C4 alkyl group is one of methyl, ethyl, isopropyl, n-propyl, and tert-butyl.

4. The compound according to claim 2, characterized in that, The C1~C7 perfluoroalkyl group is one of -CF3, -C2F5, -C3F7, -C4F9, -C5F11, -C6F13, and -C7F15; The C1~C7 perfluoroalkoxy group is one of -OCF3, -OC2F5, -OC3F7, -OC4F9, -OC5F11, -OC6F13, and -OC7F15; The C1~C7 perfluoroalkylthio group is one of -SCF3, -SC2F5, -SC3F7, -SC4F9, -SC5F11, -SC6F13, and -SC7F15.

5. The compound according to claim 1, characterized in that, Z1 is either O or S, and Z2 is either O or S. Alternatively, both Z1 and Z2 are 0; Alternatively, both Z1 and Z2 are S.

6. A compound, characterized in that, The chemical structural formula of the compound is shown below: ； Among them, Z1 and Z2 are each independently O, S or Se; Both R1 and R2 are ; Alternatively, one of R1 and R2 is The other of R1 and R2 is an unsubstituted C6~C30 aryl group; Alternatively, one of R1 and R2 is The other one of R1 and R2 is trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, phenyl with 1-5 fluorine-substituted groups, benzonitrile, fluorine-substituted biphenyl, trifluoromethyl-substituted biphenyl, biphenyl with both fluorine and cyano groups substituted, and phenyl with both fluorine and trifluoromethyl groups substituted. Z3 to Z6 are all CR4; R3 is hydrogen, and R4 is one of hydrogen, deuterium, fluorine, cyano, trifluoromethyl, trifluoromethoxy, trifluoromethylphenyl, trifluoromethoxyphenyl, di(trifluoromethyl)phenyl, phenyl with 1-5 fluorine-substituted members, pyridyl, trifluoromethyl-substituted pyridyl, pyridyl with 1-4 fluorine-substituted members, benzonitrile, or cyano-substituted pyridyl. A can be O, S, S=O, SO2, or Se.

7. A compound, characterized in that, The chemical structural formula of the compound is shown below: 。 8. The use of the compound according to any one of claims 1-7 in organic electroluminescent devices.

9. A hole injection material, characterized in that, The hole injection material includes the compound according to any one of claims 1-7.

10. The hole injection material according to claim 9, characterized in that, The hole injection material further includes a hole transport compound, wherein the hole transport compound has a mass percentage of 70 wt% to 99.5 wt%. The hole transport compound is selected from at least one of carbazole compounds, triaromatic amine compounds, biphenyl diamine compounds, fluorene compounds, phthalocyanine compounds, polythiophene, polyethylene, polybenzene sulfonic acid, quinone compounds, and hexacyanohexatribenzene.

11. A charge-generating layer material, characterized in that, The charge-generating layer material includes the compound according to any one of claims 1-7.

12. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes: a first electrode, a second electrode, and a light-emitting unit disposed between the first electrode and the second electrode; The light-emitting unit includes an electron transport functional layer, a light-emitting layer, and a hole transport functional layer, wherein the hole transport functional layer includes the compound according to any one of claims 1-7.

13. The organic electroluminescent device according to claim 12, characterized in that, The light-emitting unit is configured as a plurality of units, and a charge generation layer is provided between two adjacent light-emitting units. The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer. The P-type charge-generating layer comprises the compound according to any one of claims 1-7.

14. The organic electroluminescent device according to claim 12, characterized in that, The hole transport functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, wherein the hole injection layer includes the compound.

15. A display device, characterized in that, The display device includes the organic electroluminescent device according to any one of claims 12-14.

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