1. An organic compound having a structure according to formula I:

wherein, X₁、X₂、X₃Each independently is N or CR;

y, Z are each independently selected from O, S, NR_NOr CR_C1R_C2；

L is any one selected from single bond, substituted or unsubstituted C6-C40 arylene, substituted or unsubstituted C3-C40 heteroarylene;

R₁、R₂、R、R_N、R_C1、R_C2each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, substituted or unsubstituted C6-C40 aryl, and substituted or unsubstituted C2-C40 heteroaryl;

Ar₁、Ar₂each independently selected from any one of deuterium, halogen, cyano, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, C1-C20 alkoxy, C1-C20 alkylthio, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C2-C40 heteroaryl and substituted or unsubstituted C6-C40 arylamine;

n₁、n₂each independently selected from integers of 0 to 4.

2. An organic compound according to claim 1, wherein L, R is represented by₁、R₂、R、R_N、R_C1、R_C2、Ar₁、Ar₂The substituted substituent groups are respectively and independently selected from at least one of deuterium, cyano, halogen, unsubstituted or halogenated C1-C10 straight-chain or branched alkyl, unsubstituted or halogenated C1-C10 alkoxy, C1-C10 alkylthio, C6-C20 aryl, C2-C20 heteroaryl or C6-C18 arylamine.

3. The organic compound of claim 1, wherein X is₁、X₂、X₃At least 2 of which are N.

4. The organic compound of claim 1, wherein X is₁、X₂、X₃Are all N.

5. The organic compound of claim 4, wherein the organic compound has a structure according to formula II-1 or formula II-2:

wherein, Y, Z, L, R₁、R₂、Ar₁、Ar₂、n₁、n₂Having the same limitations as in formula I.

6. The organic compound of claim 1, wherein each of said Y, Z is independently selected from O, S or NR_N。

7. The organic compound of claim 1, wherein R is_N、R_C1、R_C2Each independently being methyl or phenyl.

8. The organic compound according to claim 1, wherein L is selected from any one of a single bond, phenylene, biphenylene, terphenylene, naphthylene, and pyridylene.

9. The organic compound of claim 1, wherein R is₁、R₂Each independently selected from hydrogen or any one of the following groups:

wherein the dotted line represents the attachment site of the group;

L₁any one selected from single bond, substituted or unsubstituted C6-C20 arylene;

X₄selected from O, S, NR_N1；

X₅Selected from O, S, NR_N2Or CR_C3R_C4；

R_N1、R_N2、R_C3、R_C4Each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, substituted or unsubstituted C6-C20 aryl, and substituted or unsubstituted C2-C20 heteroaryl;

R₁₁、R₁₂each independently selected from any one of deuterium, cyano, halogen, unsubstituted or halogenated C1-C10 straight-chain or branched alkyl, unsubstituted or halogenated C1-C10 alkoxy, C1-C10 alkylthio, C6-C20 aryl, C2-C20 heteroaryl or C6-C18 arylamine;

m₁an integer selected from 0 to 5;

m₂an integer selected from 0 to 6;

m₃an integer selected from 0 to 9;

m₄、m₆each independently selected from integers of 0 to 4;

m₅an integer selected from 0 to 3.

10. The organic compound of claim 1 or 9, wherein R is₁、R₂Each independently selected from hydrogen, substituted or unsubstituted any one of the following groups:

wherein the dotted line represents the attachment site of the group;

the substituted substituent groups are respectively and independently selected from at least one of deuterium, cyano, halogen, unsubstituted or halogenated C1-C10 straight-chain or branched alkyl, unsubstituted or halogenated C1-C10 alkoxy, C1-C10 alkylthio, C6-C20 aryl, C2-C20 heteroaryl or C6-C18 arylamine.

11. The organic compound of claim 1, wherein Ar is Ar₁、Ar₂Each independently selected from deuterium, halogen, cyano, phenyl, unsubstituted or halogenated C1-C10 straight chain or branched chain alkyl.

12. The organic compound according to claim 1, wherein the organic compound is selected from any one of the following compounds:

13. an electroluminescent material comprising the organic compound according to any one of claims 1 to 12.

14. An OLED device comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode, the material of the organic thin film layer comprising the electroluminescent material of claim 13.

15. The OLED device of claim 14, wherein the organic thin film layer comprises an electron transport layer, the material of the electron transport layer comprising the electroluminescent material of claim 13.

16. The OLED device of claim 14, wherein the organic thin film layer includes a hole blocking layer, the hole blocking layer material comprising the electroluminescent material of claim 13.

17. The OLED device of claim 14, wherein the organic thin film layer comprises a light-emitting layer, the material of the light-emitting layer comprising the electroluminescent material of claim 13.

18. A display panel comprising the OLED device of any one of claims 14-17.

Background

Compared with inorganic electroluminescent devices, Organic Light Emitting Diodes (OLEDs) have the advantages of self-luminescence, low power consumption, high contrast, wide color gamut, flexibility, foldability and the like, attract the wide attention of researchers and enterprise researchers, are successfully commercially applied, and are widely applied to multiple industries such as flexible display, flat panel display, solid state lighting and the like.

The OLED device generally has a sandwich-like stacked structure, and includes a cathode, an anode, and a plurality of organic film layers sandwiched between the two electrodes, where the organic film layers include a light-emitting layer, and other functional layers for assisting in transmission, such as an electron transport layer, a hole injection layer, and an electron injection layer. When a voltage is applied between two electrodes of the OLED device, holes generated from an anode and electrons generated from a cathode are injected into a light emitting layer, the holes and the electrons are recombined in the light emitting layer and generate excitons (exiton) which emit light while being transited from an excited state to a ground state. Therefore, in the OLED device, the material of the organic film layer and the performance thereof have very important influence on the light emitting property of the device.

The electron transport material used in conventional OLED devices is aluminum 8-hydroxyquinoline (Alq)₃) However, Alq₃Has a relatively low electron mobility ratio (about 10)^-6cm²Vs) such that electron transport and hole transport of the device are not balanced. With the commercialization and practicability of electroluminescent devices, electronic transmission materials having higher transmission efficiency and better usability are desired, and researchers have made a great deal of exploratory work in this field.

WO2007011170A discloses an imidazole derivative having a skeletal structure of naphthoimidazole, which can be used in materials for electron transport, electron injection, hole transport, and hole injection by connecting different types of substituents to the skeletal structure so that the molecule exhibits a strong p-type or n-type, and an organic electronic device comprising the same. CN101003508A discloses an electron transport compound and an organic light emitting device containing the same, wherein a series of pyrenyl electron transport compounds are designed to show good electron transport efficiency and deposition characteristics. US20060204784A and US20070048545A from kodak corporation disclose organic electroluminescent devices of mixed electron transport materials doped with: (a) a first compound having a lowest LUMO level in the layer, (b) a second compound having a LUMO level higher than that of the first compound and having a low turn-on voltage; a metal material having a work function of less than 4.2 eV. However, the electron transport material has a planar molecular structure and a large intermolecular attraction, which is not favorable for vapor deposition and application; in addition, the electron transport material also has the defects of low mobility, poor energy level matching, poor thermal stability, short service life, doping property and the like, and further development of the OLED display device is limited.

With the progress of OLED display technology, more electron transport materials currently used in the market include bathophenanthroline (batho-phenanthroline, BPhen,) Bathocuproine (BCP,) And TmPyPB: () The electron transport materials generally meet the market demand of organic electroluminescent panels, but have low glass transition temperature (generally less than 85 ℃), and the generated joule heat can cause the degradation of molecules and the change of molecular structure when the device runs, so that the panel has low efficiency and poor thermal stability. At the same time, the symmetry of the molecular structure is very regularThen, it is easily crystallized after long-term use; once the electron transport material is crystallized, the charge transition mechanism between molecules is different from the amorphous thin film mechanism in normal operation, resulting in the decrease of electron transport performance, the imbalance of electron and hole mobility of the whole device, the exciton formation efficiency is greatly reduced, and the exciton formation is concentrated at the interface of the electron transport layer and the light emitting layer, resulting in the decrease of device efficiency and the severe lifetime degradation.

Therefore, there is a need in the art to develop a wider variety of electron transport materials with higher performance to meet the application requirements of OLED display devices.

Disclosure of Invention

In order to develop more kinds of electron transport materials with more perfect performance, one of the objectives of the present invention is to provide an organic compound having a structure shown in formula I:

in the formula I, X₁、X₂、X₃Each independently is N or CR.

In the formula I, Y, Z are respectively and independently selected from O, S, NR_NOr CR_C1R_C2；

In the formula I, L is any one selected from single bond, substituted or unsubstituted C6-C40 arylene, substituted or unsubstituted C3-C40 heteroarylene; wherein "L is a single bond" means X₁The six-membered ring is directly connected with the framework structure through a single bond.

R₁、R₂、R、R_N、R_C1、R_C2Each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, substituted or unsubstituted C6-C40 aryl, and substituted or unsubstituted C2-C40 heteroaryl.

In the formula I, Ar₁、Ar₂Each independently selected from deuterium, halogen, cyano, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, C1-C20 alkoxy, C1-C20 alkylthio, substitutedOr any one of unsubstituted C3-C20 naphthenic base, substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C2-C40 heteroaryl and substituted or unsubstituted C6-C40 arylamine;

in the formula I, n₁、n₂Each independently selected from integers of 0 to 4, for example 0, 1, 2, 3 or 4.

In the present invention, each of C6 to C40 may be C6, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, or the like.

Each of C3 to C40 may be, independently, C3, C4, C5, C6, C7, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, or the like.

Each of C1 to C20 may be independently C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18, or C19.

Each of C2 to C40 may be independently C2, C3, C4, C5, C6, C7, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, or C38.

The C3 to C20 may be C4, C5, C6, C8, C10, C11, C13, C15, C17, C19, C20, or the like, independently.

In the present invention, the halogen includes fluorine, chlorine, bromine or iodine; the same meanings are given below in relation to the same descriptions.

In the organic compound provided by the invention, the mutual matching of the skeleton structure and the substituent group has good characteristics of an Electron Transport (ET) material, and the characteristics are as follows: (1) the reduction potential is high enough, so that electron transmission is facilitated, an electron injection barrier is reduced, and the voltage of the device is further reduced; (2) the HOMO energy level and the LUMO energy level are proper, so that the energy level matching of adjacent layers is facilitated, and the deeper HOMO energy level enables the adjacent layers to have certain hole blocking capacity; (3) has a higher triplet energy level E_T1The exciton of the luminous layer can be effectively blocked, and the luminous efficiency is improved; (4) has higher thermal decomposition temperature, good thermal stability and reduced Joule heat generated by the device during operation, and has long service life and high efficiency(ii) an effect; (5) the glass-transition temperature is high, the device is in an amorphous film form, the film forming uniformity is good, and the device is free of pinholes; (6) has a more three-dimensional structure, and can reduce crystallization caused by molecular stacking.

It is a second object of the present invention to provide an electroluminescent material comprising an organic compound as described in the first object.

It is a third object of the present invention to provide an OLED device comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode, the material of the organic thin film layer comprising the electroluminescent material according to the second object.

It is a fourth object of the present invention to provide a display panel including the OLED device of the third object.

Compared with the prior art, the invention has the following beneficial effects:

in the organic compound provided by the invention, through the design of a molecular structure, the organic compound has a deeper LUMO energy level, can reduce an electron injection barrier and improve the electron injection capability; the material has a deeper HOMO, so that holes can be effectively blocked, and more electrons and holes are compounded in a light-emitting layer; has higher triplet state energy level E_T1The organic electroluminescent material can effectively block excitons of the luminescent layer, and molecules have a twisted spiral ring structure, so that the molecular stacking can be reduced, the crystallization is avoided, the excellent thermal stability and the film stability are shown, and the luminescent efficiency and the service life of the device are favorably improved. The organic compound is used as an electroluminescent material, is particularly suitable for an electron transport layer and/or a hole blocking layer and the like of an OLED device, can reduce the voltage and the power consumption of the device, improves the luminous efficiency, prolongs the service life and enables the OLED device to have better comprehensive performance.

Drawings

FIG. 1 is a schematic structural diagram of an OLED device provided by the present invention;

among them, 101-anode, 102-cathode, 103-light emitting layer, 104-first organic thin film layer, 105-second organic thin film layer.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

One object of the present invention is to provide an organic compound having a structure represented by formula I:

in the formula I, X₁、X₂、X₃Each independently is N or CR.

In the formula I, Y, Z are respectively and independently selected from O, S, NR_NOr CR_C1R_C2；

In the formula I, L is any one selected from single bond, substituted or unsubstituted C6-C40 arylene, substituted or unsubstituted C3-C40 heteroarylene; wherein "L is a single bond" means X₁The six-membered ring is directly connected with the framework structure through a single bond.

R₁、R₂、R、R_N、R_C1、R_C2Each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, substituted or unsubstituted C6-C40 aryl, and substituted or unsubstituted C2-C40 heteroaryl.

In the formula I, Ar₁、Ar₂Each independently selected from any one of deuterium, halogen, cyano, substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, C1-C20 alkoxy, C1-C20 alkylthio, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C2-C40 heteroaryl and substituted or unsubstituted C6-C40 arylamine;

in the formula I, n₁、n₂Each independently selected from integers of 0 to 4, for example 0, 1, 2, 3 or 4.

In the present invention, each of C6 to C40 may be C6, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, or the like.

Each of C3 to C40 may be, independently, C3, C4, C5, C6, C7, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, or the like.

Each of C1 to C20 may be independently C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18, or C19.

Each of C2 to C40 may be independently C2, C3, C4, C5, C6, C7, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, or C38.

The C3 to C20 may be C4, C5, C6, C8, C10, C11, C13, C15, C17, C19, C20, or the like, independently.

In the present invention, the halogen includes fluorine, chlorine, bromine or iodine; the same meanings are given below in relation to the same descriptions.

The C6-C40 aryl group related to the invention illustratively includes but is not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, fluorenyl and derivatives thereof (dimethylfluorenyl, diphenylfluorenyl, spirobifluorenyl), indenyl, perylenyl, triphenylenyl, and the like.

The C2-C40 heteroaryl groups referred to in the present invention include, by way of example and not limitation: pyridyl, pyrazinyl, pyridazinyl, pyrimidinyl, triazinyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, pyridopyridyl, phenanthrolinyl, acridinyl, phenazinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, indolyl, furyl, thienyl, pyrrolyl, dibenzofuryl, dibenzothienyl, carbazolyl, or N-phenylcarbazolyl, and the like.

The C1-C20 straight chain or branched chain alkyl group related by the invention exemplarily comprises but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, tert-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl or n-octyl and the like.

The invention providesThe organic compound has a structure shown in formula I, has a 2-group benzo five-membered ring and spirofluorene condensed skeleton structure, and is connected with the skeleton structureThe purpose of electron transmission is achieved through the cooperative matching of the framework structure and the substituent; the organic compound has a deeper LUMO energy level (-1.70eV to-1.97 eV), so that smooth injection of electrons is facilitated, an injection barrier is reduced, and the voltage of an OLED device is effectively reduced; the material has a deeper HOMO energy level (-5.41eV to-5.48 eV), and can effectively block holes, so that more holes-electrons are compounded in a light emitting region; meanwhile, the organic compound has higher triplet state energy level E_T1，E_T1The electron emission efficiency is not less than 2.71eV, which can reach more than 2.90eV, and the electron emission efficiency can effectively block excitons of the light emitting layer, improve the utilization rate of the excitons and further improve the efficiency of the device. The molecules of the organic compound contain a condensed spiro structure, and the twisted structure can reduce the stacking of the molecules, avoid crystallization, ensure that the organic compound is more stable in device application, has higher glass transition temperature, and has excellent film stability and thermal stability.

The organic compound provided by the invention is used as an electroluminescent material, is particularly suitable for an electron transport layer and/or a hole blocking layer of an OLED (organic light emitting diode) device, can effectively improve the luminous efficiency of the device, reduces the working voltage and power consumption, and prolongs the working life.

In one embodiment, L, R₁、R₂、R、R_N、R_C1、R_C2、Ar₁、Ar₂The substituted substituents in (1) are each independently selected from deuterium, cyano, halogen, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) straight-chain or branched alkyl, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) alkoxy, C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) alkylthio, C6 to C20 (e.g., C6, C9, or C9, such as examples9. C10, C12, C14, C16, C18, etc.) an arylamine group.

In one embodiment, said X is₁、X₂、X₃At least 1 of which is N.

In one embodiment, said X is₁、X₂、X₃At least 2 of which are N.

In one embodiment, said X is₁、X₂、X₃Are all N.

In one embodiment, the organic compound has a structure as shown in formula II-1 or formula II-2:

wherein, Y, Z, L, R₁、R₂、Ar₁、Ar₂、n₁、n₂Having the same limitations as in formula I.

In one embodiment, each of said Y, Z is independently selected from O, S or NR_N。

In one embodiment, said R is_N、R_C1、R_C2Each independently being methyl or phenyl.

In one embodiment, L is selected from any one of a single bond, phenylene, biphenylene, terphenylene, naphthylene, or pyridylene.

In one embodiment, said R is₁、R₂Each independently selected from hydrogen or any one of the following groups:

wherein the dotted line represents the attachment site of the group.

L₁And is selected from any one of single bond and substituted or unsubstituted arylene groups of C6-C20 (for example, C6, C9, C10, C12, C14, C16 or C18).

X₄Selected from O, S, NR_N1。

X₅Selected from O, S, NR_N2Or CR_C3R_C4。

R_N1、R_N2、R_C3、R_C4Each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 (e.g., C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or C19) straight-chain or branched-chain alkyl, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C16 or C18) aryl, substituted or unsubstituted C2-C20 (e.g., C3, C4, C5, C6, C8, C10, C12, C14, C16 or C18) heteroaryl.

R₁₁、R₁₂Each independently is selected from deuterium, cyano, halogen, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10) straight-chain or branched alkyl, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10) alkoxy, C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, or C8) alkylthio, C8 to C8 (e.g., C8, or C8) heteroaryl, and the like.

m₁The integer selected from 0 to 5 is, for example, 0, 1, 2, 3, 4 or 5.

m₂The integer selected from 0 to 6 is, for example, 0, 1, 2, 3, 4, 5 or 6.

m₃The integer selected from 0 to 9 is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9.

m₄、m₆Each independently selected from integers of 0 to 4, for example 0, 1, 2, 3 or 4.

m₅The integer selected from 0 to 3 is, for example, 0, 1, 2 or 3.

In one embodiment, said R is₁、R₂Each independently selected from hydrogen, substituted or unsubstituted any one of the following groups:

wherein the dotted line represents the attachment site of the group.

The substituted substituents are each independently selected from deuterium, cyano, halogen, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) straight-chain or branched alkyl, unsubstituted or halogenated C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) alkoxy, C1 to C10 (e.g., C1, C2, C3, C4, C5, C6, C7, C8 or C8) alkylthio, C8 to C8 (e.g., C8, or C8 (e.g., at least one of arylamine.g., C8, etc.) arylamine.g., at least one of arylamine.g., a C8, etc.

In one embodiment, the Ar is₁、Ar₂Each independently selected from deuterium, halogen, cyano, phenyl, unsubstituted or halogenated C1-C10 straight chain or branched chain alkyl.

Wherein, the unsubstituted or halogenated C1-C10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) straight chain or branched chain alkyl illustratively includes but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, tert-pentyl, isopentyl, neopentyl, n-hexyl, trifluoromethyl or perfluoroethyl and the like.

In one embodiment, the organic compound is selected from any one of the following compounds:

it is a second object of the present invention to provide an electroluminescent material comprising an organic compound as described in the first object.

It is a third object of the present invention to provide an OLED device comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode, the material of the organic thin film layer comprising the electroluminescent material according to the second object.

In one embodiment, the organic thin film layer comprises an electron transport layer, the material of the electron transport layer comprising the electroluminescent material according to the second aspect.

In one embodiment, the organic thin film layer comprises a hole blocking layer, and the material of the hole blocking layer comprises the electroluminescent material according to the second aspect.

In one embodiment, the organic thin film layer includes a light emitting layer, and a material of the light emitting layer includes the electroluminescent material according to the second aspect.

In one embodiment, the organic thin film layer further includes any one or a combination of at least two of a hole injection layer, a hole transport layer, an electron blocking layer, or an electron injection layer.

In the OLED device provided by the invention, the anode material can be metal, metal oxide or conductive polymer; wherein the metal includes copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, etc., and alloys thereof, the metal oxide includes Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide, Indium Gallium Zinc Oxide (IGZO), etc., and the conductive polymer includes polyaniline, polypyrrole, poly (3-methylthiophene), etc. In addition to the above materials and combinations thereof that facilitate hole injection, known materials suitable for use as anodes are also included.

In the OLED device, the cathode material can be metal or a multi-layer metal material; wherein the metal comprises aluminum, magnesium, silver, indium, tin, titanium and the like and alloys thereof, and the multilayer metal material comprises LiF/Al and LiO₂/Al、BaF₂Al, etc. In addition to the above materials and combinations thereof that facilitate electron injection, known materials suitable for use as cathodes are also included.

In the OLED device, the organic thin film layer comprises at least one light emitting layer (EML) and any one or a combination of at least two of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Blocking Layer (EBL), a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL) or an Electron Injection Layer (EIL) which are arranged on two sides of the light emitting layer. The hole/electron injecting and transporting layer may be a carbazole-based compound, an arylamine-based compound, a benzimidazole-based compound, a metal compound, or the like, in addition to the organic compound described as one of the objects of the present invention. A cap layer (CPL) may optionally be provided on the cathode (the side remote from the anode) of the OLED device.

The schematic diagram of the OLED device is shown in fig. 1, and includes an anode 101 and a cathode 102, a light emitting layer 103 disposed between the anode 101 and the cathode 102, a first organic thin film layer 104 and a second organic thin film layer 105 disposed on two sides of the light emitting layer 103, where the first organic thin film layer 104 is any 1 or a combination of at least 2 of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), or an Electron Blocking Layer (EBL), and the second organic thin film layer 105 includes any 1 or a combination of at least 2 of a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL), or an Electron Injection Layer (EIL); a cap layer (CPL) may optionally be provided on the cathode 102 (on the side remote from 105).

The OLED device can be prepared by the following method: an anode is formed on a transparent or opaque smooth substrate, an organic thin layer is formed on the anode, and a cathode is formed on the organic thin layer. Among them, known film forming methods such as evaporation, sputtering, spin coating, dipping, ion plating, and the like can be used to form the organic thin layer.

It is a fourth object of the present invention to provide a display panel including the OLED device of the third object.

In the invention, the organic compound with the structure shown in the formula I can be prepared by the following synthetic route:

wherein, X₁、X₂、X₃、Y、Z、L、R₁、R₂、Ar₁、Ar₂、n₁、n₂Having the same limits as in formula I; u shape₁、U₂、U₃Each independently selected from halogen (e.g. chlorine, bromine or iodine).

Several preparation examples of the organic compounds according to the invention are listed below by way of example:

example 1

An organic compound P1, having the structure:

the preparation method comprises the following steps:

under nitrogen atmosphere, in a reaction flask with toluene: ethanol: adding a reaction solvent according to the proportion of 7:2:1, and then sequentially adding K₂CO₃(10mmol, aq.), intermediate reactant A1(5mmol), reactant a-1(5mmol), and tetrakis (triphenylphosphine) palladium Pd (PPh)₃)₄(0.25mmol), the temperature was raised to 80 ℃ and the reaction was carried out overnight. After the reaction is finished, cooling to room temperature, adding dichloromethane/H₂Extracting with O, and collecting organic phase with anhydrous Na₂SO₄Drying, collecting the filtrate by suction filtration, removing the solvent by rotation and purifying by column chromatography gave intermediate B1 (yield 72%).

MALDI-TOF MS (m/z) was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: c₂₄H₁₂BrIO₂Calculating the value: 537.91, found: 538.20.

under nitrogen atmosphere, in a reaction flask with toluene: ethanol: adding a reaction solvent according to the proportion of 7:2:1, and then sequentially adding K₂CO₃(8mmol, aq.), intermediate reactant B1(4mmol), reactant B-1(4mmol), and Pd (PPh)₃)₄(0.2mmol), the temperature was raised to 80 ℃ and the reaction was carried out overnight. After the reaction is finished, cooling to room temperature, adding dichloromethane/H₂Extracting with O, and collecting organic phase with anhydrous Na₂SO₄Drying, collecting the filtrate by suction filtration, removing the solvent by rotation, and purifying by column chromatography to obtain intermediate C1-1 (yield 75%).

MALDI-TOF MS(m/z)：C₃₉H₂₂BrN₃O₂Calculating the value: 643.09, found: 643.30.

under nitrogen atmosphere, adding the intermediate compound C1-1(1mmol) into anhydrous Tetrahydrofuran (THF), stirring and cooling at-78 ℃, dropwise adding 1.6M n-butyllithium (n-BuLi, 1.1mmol), and reacting at-78 ℃ for 2 h; slowly dropping the compound c-1(1.2mmol) into the low-temperature reaction liquid, and continuing the reaction at low temperature for 2h after the dropping is finished, and then standing overnight at room temperature. Quenching with a small amount of water, adding dichloromethane/H₂Extracting with O, collecting organic phase, and extracting with anhydrous Na₂SO₄Drying, filtering, collecting filtrate, and removing solvent to obtain crude product;

the crude product is added to acetic acid (AcOH) under nitrogen, stirred and heated, and reacted at 120 ℃ for 2h, then hydrochloric acid is added, and the reaction is heated at the temperature for 12 h. Cooling and extraction were carried out, the organic phase was collected and the solvent was removed by rotation, and purification by column chromatography gave the desired product P1 (yield 68%).

MALDI-TOF MS(m/z)：C₅₂H₂₉N₃O₂Calculating the value: 727.23, found: 727.45, respectively;

elemental analysis (%): calculated values: c85.81, H4.02, N5.77; test values are: c85.80, H4.01, N5.79.

Example 2

An organic compound P73, having the structure:

the preparation method differs from example 1 only in that the reactant b-1 in step (2) is replaced by b-2Alternatively, other raw materials and process parameters were the same as in example 1 to obtain the target product P73 with a yield of 70%.

MALDI-TOF MS(m/z)：C₅₈H₃₃N₃O₂Calculating a value: 803.26, found: 803.46, respectively;

elemental analysis (%): calculated values: c86.65, H4.14, N5.23; test values are: c86.64, H4.13, N5.25.

Example 3

An organic compound P77, having the structure:

the preparation method differs from example 1 only in that the reactant b-1 in step (2) is replaced by b-3Alternatively, other raw materials and process parameters were the same as in example 1 to obtain the target product P77 with a yield of 67%.

MALDI-TOF MS(m/z)：C₆₄H₃₅N₃O₃Calculating the value: 893.27, found: 893.50, respectively;

elemental analysis (%): calculated values: c85.98, H3.95, N4.70, test values: c85.97, H3.94, N4.73.

Example 4

An organic compound P31, having the structure:

the preparation method comprises the following steps:

under nitrogen atmosphere, in a reaction flask with toluene: ethanol: adding a reaction solvent according to the proportion of 7:2:1, and then sequentially adding K₂CO₃(10mmol, aq.), intermediate reactant A1(5mmol), reactant a-2(5mmol), and Pd (PPh)₃)₄(0.25mmol), the temperature was raised to 80 ℃ and the reaction was carried out overnight. After the reaction is finished, coolingCooling to room temperature, adding dichloromethane/H₂Extracting with O, and collecting organic phase with anhydrous Na₂SO₄Drying, collecting the filtrate by suction filtration, removing the solvent by rotation and purifying by column chromatography gave intermediate B2 (yield 74%).

MALDI-TOF MS(m/z)：C₂₄H₁₂BrClO₂Calculating the value: 445.97, found: 446.20.

under nitrogen atmosphere, in a reaction flask with toluene: ethanol: adding a reaction solvent according to the proportion of 7:2:1, and then sequentially adding K₂CO₃(8mmol, aq.), intermediate reactant B2(4mmol), reactant B-1(4mmol), and Pd (PPh)₃)₄(0.2mmol), the temperature was raised to 90 ℃ and the reaction was carried out overnight. After the reaction is finished, cooling to room temperature, adding dichloromethane/H₂Extracting with O, and collecting organic phase with anhydrous Na₂SO₄Drying, collecting the filtrate by suction filtration, removing the solvent by rotation, and purifying by column chromatography to obtain intermediate C2-1 (yield 70%).

MALDI-TOF MS(m/z)：C₃₉H₂₂ClN₃O₂Calculating the value: 599.14, found: 599.35.

under nitrogen atmosphere, adding intermediate compound C2-1(1mmol) into anhydrous THF, stirring and cooling at-78 deg.C, dropwise adding 1.6M n-BuLi (1.1mmol), and reacting at-78 deg.C for 2 h; slowly dropping the compound c-1(1.2mmol) into the low-temperature reaction liquid, and continuing the reaction at low temperature for 2h after the dropping is finished, and then standing overnight at room temperature. Quenching with a small amount of water, adding dichloromethane/H₂Extracting with O, collecting organic phase, and extracting with anhydrous Na₂SO₄Drying, filtering, collecting filtrate, and removing solvent to obtain crude product;

the crude product is added into acetic acid under nitrogen, stirred and heated, and reacted for 2 hours at 120 ℃, and then hydrochloric acid is added, and the reaction is heated and reacted for 12 hours at the temperature. Cooling and extraction were carried out, the organic phase was collected and the solvent was removed by rotation, and purification by column chromatography gave the desired product P31 (yield 62%).

MALDI-TOF MS(m/z)：C₅₂H₂₉N₃O₂Calculating the value: 727.23, found: 727.50, respectively;

elemental analysis (%): calculated values: c85.81, H4.02, N5.77; test values are: c85.80, H4.01, N5.80.

Example 5

An organic compound P55, having the structure:

the preparation method differs from example 4 only in that the reactant b-1 in step (2) is replaced by b-4Alternatively, other raw materials and process parameters were the same as in example 4 to obtain the target product P55 with a yield of 60%.

MALDI-TOF MS(m/z)：C₅₈H₃₁N₃O₃Calculating the value: 817.24, found: 817.45, respectively;

elemental analysis (%): calculated values: c85.17, H3.82, N5.14; test values are: c85.16, H3.81, N5.16.

Example 6

An organic compound P61, having the structure:

the preparation method differs from example 4 only in that the reactant b-1 in step (2) is replaced by b-2Replacement ofThe other raw materials and process parameters were the same as in example 4, and the target product P61 was obtained with a yield of 64%.

MALDI-TOF MS(m/z)：C₅₈H₃₃N₃O₂Calculating the value: 803.26, found: 803.55, respectively;

elemental analysis (%): calculated values: c86.65, H4.14, N5.23; test values are: c86.64, H4.13, N5.25.

Example 7

An organic compound P62, having the structure:

the preparation method differs from example 4 only in that the reactant b-1 in step (2) is replaced by b-5Alternatively, other raw materials and process parameters were the same as in example 4 to obtain the target product P62 with a yield of 65%.

MALDI-TOF MS(m/z)：C₅₈H₃₃N₃O₂Calculating the value: 803.26, found: 803.50, respectively;

elemental analysis (%): calculated values: c86.65, H4.14, N5.23; test values are: c86.64, H4.13, N5.25.

Example 8

An organic compound P131, having the structure:

the preparation method differs from example 4 only in that the reactant b-1 in step (2) is replaced by b-6And the other raw materials and process parameters are the same as those in example 4, so that the target product P131 is obtained, and the yield is 66%.

MALDI-TOF MS(m/z)：C₅₇H₃₂N₄O₂Calculating the value: 804.25, found: 804.45, respectively;

elemental analysis (%): calculated values: c85.06, H4.01, N6.96; test values are: c85.05, H4.00, N6.70.

Example 9

An organic compound P134, having the structure:

the preparation method differs from example 4 only in that the compound c-1 in step (3) is used as c-2And the other raw materials and process parameters are the same as those in example 4, so that the target product P134 is obtained, and the yield is 62%.

MALDI-TOF MS(m/z)：C₅₃H₂₈N₄O₂Calculating the value: 752.22, found: 752.51, respectively;

elemental analysis (%): calculated values: c84.56, H3.75, N7.44; test values are: c84.55, H3.74, N7.47.

Example 10

An organic compound P89, having the structure:

the preparation method differs from example 4 only in that the intermediate reactant A1 in step (1) is replaced by A2Alternatively, other raw materials and process parameters were the same as in example 4 to obtain the target product P89 with a yield of 64%.

MALDI-TOF MS(m/z)：C₅₂H₂₉N₃OS, calculated value: 743.20, found: 743.50, respectively;

elemental analysis (%): calculated values: c83.96, H3.93, N5.65; test values are: c83.95, H3.92, N5.68.

Example 11

An organic compound P101, having the structure:

the preparation method differs from example 4 only in that the intermediate reactant A1 in step (1) is replaced by A2Alternatively, reactant a-2 is replaced by a-3And the other raw materials and process parameters are the same as those in example 4, so that the target product P101 is obtained, and the yield is 63%.

MALDI-TOF MS(m/z)：C₅₂H₂₉N₃S₂Calculating the value: 759.18, found: 759.45, respectively;

elemental analysis (%): calculated values: c82.19, H3.85, N5.53; test values are: c82.18, H3.84, N5.55.

Example 12

An organic compound P113, having the structure:

the preparation method differs from example 4 only in that the intermediate reactant A1 in step (1) is replaced by A3And the other raw materials and process parameters are the same as those in example 4, so that the target product P113 is obtained, and the yield is 61%.

MALDI-TOF MS(m/z)：C₅₈H₃₄N₄O, calculated value: 802.27, found in factThe value: 802.56, respectively;

elemental analysis (%): calculated values: c86.76, H4.27, N6.98; test values are: c86.75, H4.25, N7.01.

Simulated calculation of compounds:

aiming at the organic compound provided by the invention, the Density Functional Theory (DFT) is applied, the distribution and energy levels of molecular front line orbitals HOMO and LUMO are obtained by optimizing and calculating under the calculation level of B3LYP/6-31G (d) by a Guassian 09 package (Guassian Inc.), and meanwhile, the lowest singlet state energy level E of a compound molecule is calculated based on time-dependent density functional theory (TD-DFT) simulation_S1And lowest triplet energy level E_T1The results are shown in Table 1.

TABLE 1

	Organic compounds	HOMO(eV)	LUMO(eV)	ES1(eV)	ET1(eV)
						Example 1	P1	-5.45	-1.77	3.34	2.90
Example 2	P73	-5.41	-1.70	3.39	2.92
						Example 3	P77	-5.42	-1.73	3.37	2.91
Example 4	P31	-5.47	-1.92	3.16	2.72
						Example 5	P55	-5.48	-1.94	3.16	2.72
Example 6	P61	-5.43	-1.82	3.34	2.83
						Example 7	P62	-5.46	-1.92	3.24	2.67
Example 8	P131	-5.47	-1.97	3.30	2.80
						Example 9	P134	-5.48	-1.95	3.17	2.72
Example 10	P89	-5.46	-1.92	3.17	2.72
						Example 11	P101	-5.45	-1.92	3.16	2.72
Example 12	P113	-5.41	-1.91	3.16	2.71

As can be seen from Table 1, the organic compound provided by the invention has a deeper LUMO energy level (-1.70eV to-1.97 eV), can reduce the barrier of electron transport, improves the injection capability of electrons, and effectively reduces the voltage of an OLED device; the organic compound has a deeper HOMO energy level (-5.41eV to-5.48 eV), and can effectively block holes, so that more holes and electrons are compounded in a light emitting region; meanwhile, the organic compounds all have higher triplet state energy level (E)_T1Not less than 2.71eV), can block excitons of the light emitting layer, and improve the utilization rate of the excitons; therefore, the organic compound provided by the invention can realize higher luminous efficiency. In addition, the organic compound also has a spiral ring structure, so that the molecules have a twisted structure, the stacking of the molecules can be reduced, the crystallization of the molecules is avoided, and the organic compound is more stable in device application.

The following are some examples of applications of the organic compounds of the present invention in OLED devices:

application example 1

An OLED device, comprising the following structures arranged in sequence: a substrate, an anode (indium tin oxide, ITO), a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode (aluminum electrode); the preparation steps of the OLED device are as follows:

(1) respectively carrying out ultrasonic treatment on a glass substrate with an ITO anode (the thickness is 100nm) in isopropanol and deionized water for 30min, then exposing the glass substrate to ozone for about 10min for cleaning, and mounting the cleaned glass substrate on vacuum deposition equipment;

(2) evaporating a compound a on the ITO anode in vacuum with the thickness of 10nm to be used as a hole injection layer;

(3) vacuum evaporating a compound b on the hole injection layer to form a hole transport layer with the thickness of 40 nm;

(4) vacuum evaporating a compound c on the hole transport layer, wherein the thickness of the compound c is 10nm and the compound c is used as an electron blocking layer;

(5) a compound d and a compound e are evaporated on the electron blocking layer in vacuum, the doping proportion of the compound d is 5% (mass ratio), the thickness of the compound d is 20nm, and the compound d is used as a light emitting layer;

(6) a compound f is evaporated on the luminescent layer in vacuum, the thickness of the compound f is 10nm, and the compound f is used as a hole blocking layer;

(7) vacuum evaporation of the organic compound P1 provided in example 1 of the present invention, which has a thickness of 30nm, on the hole-blocking layer was performed to obtain an electron-transporting layer;

(8) evaporating compound LiF on the electron transport layer in vacuum with the thickness of 2nm to be used as an electron injection layer;

(9) and (3) performing vacuum evaporation on an aluminum electrode on the electron injection layer, wherein the thickness of the aluminum electrode is 100nm, and the aluminum electrode is used as a cathode to obtain the OLED device.

The structure of the compound used in the OLED device is as follows:

application examples 2 to 12 and comparative example 1

An OLED device differing from application example 1 only in that the organic compound P1 in step (7) was replaced with equal amounts of the organic compounds P73, P77, P31, P55, P61, P62, P131, P134, P89, P101, P113, comparative compound 1, respectively; other hierarchical structures, materials and preparation methods are the same as in application example 1.

Performance evaluation of OLED devices:

according to the current density and the brightness of the OLED device under different voltages, the current density (10 mA/cm) is obtained under the same current density²) Operating voltage v (v) and current efficiency CE (cd/a); the lifetime LT95(h at 50 mA/cm) was obtained by measuring the time when the luminance of the OLED device reached 95% of the initial luminance²Under test conditions); the test data are shown in table 2.

TABLE 2

OLED device	Electron transport layer material	V(V)	CE(cd/A)	LT95(h)
					Application example 1	P1	4.11	14.8	63
Application example 2	P73	4.13	14.6	64
					Application example 3	P77	4.14	14.5	62
Application example 4	P31	4.09	15.7	64
					Application example 5	P55	4.07	15.4	66
Application example 6	P61	4.01	16.1	69
					Application example 7	P62	4.03	15.9	67
Application example 8	P131	4.02	15.7	63
					Application example 9	P134	4.08	15.5	61
Application example 10	P89	4.10	15.3	63
					Application example 11	P101	4.12	15.1	62
Application example 12	P113	4.13	14.9	60
					Comparative example 1	Comparative Compound 1	4.21	13.9	51

As can be seen from Table 2, the organic compound provided by the invention is applied to an electron transport layer of an OLED device, so that the OLED device has lower working voltage, higher luminous efficiency and longer device life, wherein the working voltage is less than or equal to 4.14V and is as low as 4.01-4.14V, the current efficiency CE is more than or equal to 14.5cd/A, and the life LT95 is more than or equal to 60 h. Compared with comparative example 1, the OLED device adopting the compound provided by the invention has the advantages that the working voltage is reduced, the efficiency and the service life are improved, and the organic compound provided by the invention has a deeper LUMO energy level, so that the potential barrier of electron injection is reduced, and the working voltage of the device is reduced; the material has a deeper HOMO value, can effectively block holes, is beneficial to widening a light-emitting composite region and improving the light-emitting efficiency of a device; having a higher E_T1Can block excitons of the luminescent layer and improve the utilization rate of the excitons; meanwhile, the organic compound provided by the invention has good thermal stability and film-forming property, is beneficial to the stability of devices, and prolongs the service life of the devices.

The applicant states that the present invention is illustrated by the above examples of an organic compound, an electroluminescent material and its use, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps to be carried out. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.