Compound containing azabenzene structure and organic electroluminescent device thereof

Abstract

The invention discloses a compound containing an azabenzene structure and an organic electroluminescent device thereof, and belongs to the technical field of semiconductor materials. The structure of the compound is shown as a general formula (1). The compound containing the azabenzene structure is applied to an organic thin film layer of an organic electroluminescent device. The compound containing the azabenzene structure has good electron regulation and control ability and hole and exciton blocking ability, and also has good stability, and when the compound containing the azabenzene structure is used as a hole blocking layer material of an organic electroluminescent device, the hole blocking layer material has good electron regulation and control ability and hole and exciton blocking ability. The light-emitting efficiency and the service life of the organic light-emitting device can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor materials, in particular to a compound containing a nitrogen-heterobenzene structure and an organic electroluminescent device thereof. Background Art

[0002] Organic light-emitting diode (OLED) technology can be used to manufacture both new display products and new lighting products, and is expected to replace existing liquid crystal displays and fluorescent lighting, with broad application prospects. An organic light-emitting diode (OLED) has a sandwich-like structure, including an electrode material film layer and an organic photoelectric functional material layer sandwiched between different electrode material film layers. The organic photoelectric functional material layer includes at least one light-emitting layer, and various organic photoelectric functional materials are stacked together according to their intended use to form an organic light-emitting device. As an electric current device, when a voltage is applied to the electrodes at both ends and the electric field acts on the positive and negative charges in the organic photoelectric functional material layer, the positive and negative charges further recombine in the light-emitting layer, generating organic electroluminescence.

[0003] Currently, organic electroluminescent display technology has been applied in smartphones, tablets, televisions, and other fields. However, compared with the actual product application requirements, the luminous efficiency and service life of organic electroluminescent devices need to be further improved. To achieve the continuous improvement of the performance of organic electroluminescent devices, it is necessary to continuously research and innovate organic optoelectronic functional materials to create higher-performance organic optoelectronic functional materials.

[0004] Organic optoelectronic functional materials used in organic electroluminescent devices can be divided into two major categories based on their uses: charge injection and transport materials and luminescent materials. Furthermore, charge injection and transport materials can be further divided into electron injection and transport materials, electron blocking materials, hole injection and transport materials, and hole blocking materials. For organic electroluminescent devices, holes are injected from the anode and electrons are injected from the cathode. They are transported in the organic functional layer and finally meet in the light-emitting layer to form excitons, which then recombine and emit light. The hole blocking layer is located between the light-emitting layer and the electron transport layer. It can block the diffusion or migration of holes to the electron transport layer and reduce the energy loss of excitons, playing a role in interface modification and auxiliary regulation of electron injection / transport. Due to the poor electron control ability and hole and exciton blocking ability of existing hole blocking layer materials, it is difficult to achieve an efficient electron-hole balance within the light-emitting layer, making it difficult to obtain high-efficiency, long-life devices. Therefore, it is necessary to further improve the electron injection and transport ability, as well as the hole and exciton blocking ability of the hole blocking layer material, improve the stability of the material, achieve an efficient balance of excitons, and improve the efficiency and life of the device. Summary of the Invention

[0005] In response to the above-mentioned problems existing in the prior art, the present invention provides a compound containing a nitrogen-containing heterobenzene structure and an organic electroluminescent device thereof. The compound of the present invention has excellent hole-blocking ability and good material stability. When applied to organic electroluminescent devices, it can effectively improve the luminous efficiency and service life of the device.

[0006] A compound containing a nitrogen-containing heterobenzene structure, wherein the structure of the compound is shown in general formula (1):

[0007]

[0008] In the general formula (1), Z1, Z2, and Z3 are each independently represented by CH or N; at least one of Z1, Z2, and Z3 is represented by N; Z1, Z2, and Z3 may be the same or different;

[0009] Ar1 and Ar2 are each independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted carbazolyl group; Ar1 ​​and Ar2 may be the same or different;

[0010] L1 and L2 each independently represent a single bond, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted pyridylene group; L1 and L2 may be the same or different;

[0011] R represents the structure shown in general formula (2);

[0012]

[0013] The asterisk * in the general formula (2) indicates the connection position between the general formula (2) and L2;

[0014] In the general formula (2), R1, R2, R3, R4, and R5 are each independently any one of a hydrogen atom, a C1-C20 alkyl group, and a C3-C20 cycloalkyl group; at least one of R1, R2, R3, R4, and R5 is not a hydrogen atom, and R1, R2, R3, R4, and R5 may be the same or different;

[0015] The substituents for the above-mentioned substitutable groups are selected from deuterium atoms, C1-C20 alkyl groups, C3-C20 cycloalkyl groups, cyano groups, phenyl groups, naphthyl groups, biphenyl groups, terphenyl groups, pyridyl groups, pyrimidyl groups, phenanthrenyl groups, dibenzofuranyl groups, dibenzothiophenyl groups or carbazolyl groups;

[0016] The general formula (1) does not represent the structure shown in the general formula (3);

[0017]

[0018] Furthermore, any hydrogen atoms in the compound represented by the general formula (1) may be partially or completely replaced by deuterium atoms.

[0019] Furthermore, the structure of the compound is represented by any one of the general formulas (2-1) to (2-4):

[0020]

[0021] In general formulae (2-1) to (2-4), Z1, Z2, Z3, Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 have the same meanings as described above.

[0022] Furthermore, any hydrogen atoms in the compounds represented by the general formula (2-1) to the general formula (2-4) may be partially or completely replaced by deuterium atoms.

[0023] Furthermore, the structure of the compound is shown in any one of the general formulas (3-1) to (3-5):

[0024]

[0025]

[0026] In general formulae (3-1) to (3-5), Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 have the same meanings as described above.

[0027] Furthermore, any hydrogen atoms in the compounds represented by the general formula (3-1) to the general formula (3-5) may be partially or completely replaced by deuterium atoms.

[0028] Furthermore, the structure of the compound is shown in any one of the general formulas (4-1) to (4-4):

[0029]

[0030] In general formulae (4-1) to (4-4), Z1, Z2, Z3, Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 have the same meanings as described above.

[0031] Furthermore, any hydrogen atoms in the compounds represented by the general formula (4-1) to the general formula (4-4) may be partially or completely replaced by deuterium atoms.

[0032] Furthermore, the structure of the compound is shown in any one of the general formulas (5-1) to (5-42):

[0033]

[0034]

[0035]

[0036] In general formulae (5-1) to (5-42), Z1, Z2, Z3, Ar1, Ar2, and R have the same meanings as described above.

[0037] Furthermore, any hydrogen atoms in the compounds represented by the general formula (5-1) to the general formula (5-42) may be partially or completely replaced by deuterium atoms.

[0038] Furthermore, the R is represented by the structure shown in the general formula (2a-1) or the general formula (2a-2):

[0039]

[0040] In the general formula (2a-1) and the general formula (2a-2), the meanings of R1, R2, R3, R4, and R5 are the same as those described above.

[0041] Furthermore, R is represented by the structure shown in general formula (2b-1), general formula (2b-2), general formula (2b-3) or general formula (2b-4):

[0042]

[0043]

[0044] In general formula (2b-1), general formula (2b-2), general formula (2b-3) and general formula (2b-4), the meanings of R1, R2, R3, R4 and R5 are the same as those described above.

[0045] Furthermore, the R is represented by the structure shown in the general formula (2c-1) or the general formula (2c-28):

[0046]

[0047]

[0048] In general formula (2c-1) and general formula (2c-28), the meanings of R1, R2, R3, R4, and R5 are the same as those described above.

[0049] Furthermore, R1, R2, R3, R4, and R5 are each independently represented by a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-pentyl group, a tert-butyl group, a butyl group, an adamantyl group, a cyclopentyl group, or a cyclohexyl group.

[0050] Furthermore, at least one of R1, R2, R3, R4, and R5 is tert-butyl.

[0051] Furthermore, one of R1, R2, R3, R4, and R5 is tert-butyl.

[0052] Furthermore, the specific structure of the compound is any one of the following structures:

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] An organic electroluminescent device comprises a substrate, a first electrode, an organic thin film layer and a second electrode in sequence, wherein the organic thin film layer contains the compound containing nitrogen-containing heterobenzene structure of the present invention.

[0087] Furthermore, the organic thin film layer includes a hole transport region thin film layer, a light emitting region thin film layer and an electron transport region thin film layer, and the electron transport region thin film layer contains the nitrogen-containing heterobenzene structure compound of the present invention.

[0088] Furthermore, the electron transport region thin film layer comprises a hole blocking layer, and the hole blocking layer contains the compound having the nitrogen-containing heterobenzene structure of the present invention.

[0089] Furthermore, the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the compound having the nitrogen-containing heterobenzene structure of the present invention.

[0090] Furthermore, the hole transport region thin film layer comprises a hole injection layer, a hole transport layer and an electron blocking layer, the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the nitrogen-containing heterobenzene structure compound of the present invention.

[0091] The beneficial technical effects of the present invention are:

[0092] The nitrogen-containing heterobenzene structure compound of the present invention has more excellent hole-blocking and exciton-blocking capabilities, and can effectively block the diffusion or movement of holes to the electron transport layer, so that the holes are better confined to the light-emitting area, ensuring that more holes and electrons in the light-emitting layer form excitons, increasing the exciton concentration, and thus improving the luminous efficiency and service life of the device.

[0093] The structural characteristics of the nitrogen-containing heterobenzene structure compound of the present invention enable the compound of the present invention to have more excellent electron regulation ability, supplement the electron transport layer, have suitable electron injection and transport properties, can better adapt to the electron-hole balance inside the light-emitting layer, and improve the device's luminous efficiency and device life. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 This is a schematic structural diagram of the materials listed in the present invention applied to an organic electroluminescent device.

[0095] In the figure, 1, transparent substrate layer; 2, anode layer; 3, hole injection layer; 4, hole transport layer; 5, electron blocking layer; 6, light-emitting layer; 7, hole blocking layer; 8, electron transport layer; 9, electron injection layer; 10, cathode layer; 11, light extraction layer.

[0096] Figure 2 This is the H NMR spectrum of compound 13 from Synthesis Example 6 in deuterated chloroform.

[0097] Figure 3 This is the H NMR spectrum of compound 21 from Synthesis Example 8 in deuterated chloroform.

[0098] Figure 4 This is the H NMR spectrum of Compound 340 from Synthesis Example 19 in deuterated chloroform. DETAILED DESCRIPTION

[0099] The technical solution of the present invention will be described in detail below in conjunction with the implementation scheme.

[0100] In the present invention, unless otherwise specified, HOMO means the highest occupied molecular orbital of a molecule, and LUMO means the lowest unoccupied molecular orbital of a molecule.

[0101] In the drawings, the dimensions of layers and regions may be exaggerated for clarity. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Furthermore, it will be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0102] In the present invention, when describing electrodes, organic electroluminescent devices, and other structures, terms such as "upper" and "lower" that indicate orientation refer only to a particular state and do not imply that the structure can exist only in the described orientation. Conversely, if the structure can be repositioned, such as inverted, the orientation of the structure will change accordingly. Specifically, in the present invention, the "lower" side of an electrode refers to the side of the electrode that is closest to the substrate during fabrication, while the opposite side, farther from the substrate, is the "upper" side.

[0103] The C1-C20 alkyl group (including straight-chain alkyl groups and branched-chain alkyl groups) described in the present invention refers to an alkyl group with 1 to 20 carbon atoms, preferably an alkyl group with 1 to 10 carbon atoms, preferably an alkyl group with 1 to 5 carbon atoms, preferably an alkyl group with 1 to 4 carbon atoms, preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, an isobutyl group, a sec-butyl group, a neopentyl group, an n-pentyl group, an isopentyl group, an octyl group, a heptyl group, a n-decyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 1-butylpentyl group, etc., but is not limited thereto.

[0104] The C3-C20 cycloalkyl group of the present invention refers to a monovalent monocyclic saturated hydrocarbon group containing 3 to 20 carbon atoms as ring atoms. In this article, C4-C9 cycloalkyl groups are preferably used, C5-C8 cycloalkyl groups are more preferably used, and C5-C7 cycloalkyl groups are particularly preferably used. Non-limiting examples thereof include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, adamantyl, and cycloheptyl groups.

[0105] The C3-C20 cycloalkylene group of the present invention refers to a divalent monocyclic saturated hydrocarbon group containing 3 to 20 carbon atoms as ring atoms. In this article, C4-C9 cycloalkylene groups are preferably used, C5-C8 cycloalkylene groups are more preferably used, and C5-C7 cycloalkylene groups are particularly preferably used. Non-limiting examples thereof include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, 4-methylcyclohexylene, 4,4-dimethylcyclohexylene, adamantylene, and cycloheptylene, but are not limited thereto.

[0106] organic electroluminescent devices

[0107] The organic electroluminescent device of the present invention may be a bottom-emitting organic electroluminescent device, a top-emitting organic electroluminescent device or a stacked organic electroluminescent device, which is not particularly limited.

[0108] The organic electroluminescent device of the present invention comprises, in order, a substrate, a first electrode, an organic thin film layer, and a second electrode. The organic thin film layer comprises a hole transport region thin film layer, a light emitting region thin film layer, and an electron transport region thin film layer. The hole transport region thin film layer comprises a hole injection layer, a hole transport layer, and an electron blocking layer, while the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer, and an electron injection layer. Furthermore, a light extraction layer may be provided on the second electrode.

[0109] The organic electroluminescent device of the present invention may include layers and the positional relationship of each layer is as follows: it may include a substrate, a first electrode, 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, a second electrode and a light extraction layer. If the above layers exist, the first electrode is above the substrate, the hole injection layer is above the first electrode, the hole transport layer is above the hole injection layer, the electron blocking layer is above the hole transport layer, the light-emitting layer is above the electron blocking layer, the hole blocking layer is above the light-emitting layer, the electron transport layer is above the hole blocking layer, the electron injection layer is above the electron transport layer, the second electrode is above the electron injection layer, and the light extraction layer is above the second electrode.

[0110] As the substrate for the organic electroluminescent device of the present invention, any substrate commonly used for organic electroluminescent devices can be used. Examples include transparent substrates such as glass or transparent plastic substrates; opaque substrates such as silicon substrates; and flexible PI film substrates. Different substrates have varying mechanical strength, thermal stability, transparency, surface smoothness, and water resistance. Depending on the properties of the substrate, its application varies. In the present invention, a transparent glass substrate is preferably used, and the thickness of the substrate is not particularly limited.

[0111] A first electrode is formed on a substrate, and the first electrode and the second electrode may be opposite to each other. The first electrode may be an anode or a cathode. In the present invention, the first electrode serves as an anode, and the anode material is preferably a material with a high work function so that holes are easily injected into the organic functional material layer. Non-limiting examples of anode materials include, but are not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In) and magnesium-silver (Mg-Ag). The first electrode may have a single-layer structure or a multilayer structure including two or more layers. In addition, the thickness of the anode depends on the material used, typically 50-500nm, preferably 70-300nm and more preferably 100-200nm.

[0112] A hole injection layer, a hole transport layer, and an electron blocking layer may be disposed between the first electrode and the light emitting layer.

[0113] The hole injection layer may comprise a host material and a P-type dopant material, wherein the host material may be selected from conventional hole transport materials in the prior art, preferably the same organic material as the hole transport layer, and the P-type dopant material is a compound with charge conductivity disclosed in the prior art, and may be selected from the compounds disclosed in the following patent documents: WO2011073149A, EP1968131A1, EP2276085A1, EP2213662A1, EP1722602A1, EP2 045848A1, DE102007031220A1, US20100181555A1, US20100102709A1, WO2009003455A1, WO2010094378A1, WO2011120709A1, US20100096600A1, DE102012209523A1, CN101728485A and WO2012095143A1, but are not limited thereto.

[0114] For example, the compound shown below:

[0115]

[0116] According to the present invention, P-1 is preferably used as the P-type dopant material.

[0117] The thickness of the hole injection layer of the present invention may be 1-100 nm, preferably 2-50 nm and more preferably 5-20 nm.

[0118] The material of the hole transport layer is preferably a material having high hole mobility, which enables holes to be transferred from the anode or the hole injection layer to the light emitting layer.

[0119] Preferably, the hole transport layer material of the present invention may be selected from the following compounds disclosed in the prior art:

[0120]

[0121] The thickness of the hole transport layer of the present invention may be 5-200 nm, preferably 10-180 nm, and more preferably 20-150 nm.

[0122] The electron blocking layer material must have a triplet state (T1) energy level higher than the T1 energy level of the main material in the light-emitting layer, thereby preventing energy loss from the light-emitting layer material. The HOMO energy level of the electron blocking layer material must be between the HOMO energy level of the hole transport layer material and the HOMO energy level of the main material in the light-emitting layer, facilitating hole injection from the positive electrode into the light-emitting layer. Furthermore, the electron blocking layer material must have a high hole mobility, facilitating hole transport and reducing device power consumption. The LUMO energy level of the electron blocking layer material must be higher than the LUMO energy level of the main material in the light-emitting layer, acting as an electron blocker. This means that the electron blocking layer material must have a wide bandgap (Eg). Materials that meet these requirements for electron blocking layers include triarylamine derivatives, fluorene derivatives, spirofluorene derivatives, dibenzofuran derivatives, and carbazole derivatives.

[0123] In one embodiment of the present invention, the electron blocking layer material of the present invention may be selected from the following compounds disclosed in the prior art:

[0124]

[0125] According to the present invention, the thickness of the electron blocking layer may be 1-200 nm, preferably 5-150 nm, and more preferably 5-50 nm.

[0126] According to the present invention, the light-emitting layer is located between the electron-blocking layer and the hole-blocking layer. The material of the light-emitting layer is a material that can emit visible light by respectively receiving holes from the hole-transporting region and electrons from the electron-transporting region and combining the received holes and electrons. The light-emitting layer may include a host material and a dopant material. The host material can be divided into red light-emitting host materials, green light-emitting host materials, blue light-emitting host materials, etc. The dopant material can be divided into red light-emitting dopant materials, green light-emitting dopant materials, blue light-emitting dopant materials, etc. The present invention uses a blue light-emitting device as an example. As the host material and guest material of the light-emitting layer of the organic electroluminescent device of the present invention, the host material can be one or a combination of two of anthracene derivatives, quinoxaline derivatives, triazine derivatives, xanthone derivatives, diphenyl ketone derivatives, carbazole derivatives, pyridine derivatives, or pyrimidine derivatives. The guest material can be a pyrene derivative, a boron derivative, a chrysene derivative, a spirofluorene derivative, an iridium complex, or a platinum complex.

[0127] The thickness of the light-emitting layer of the present invention may be 5-60 nm, preferably 10-50 nm, and more preferably 20-45 nm.

[0128] A hole-blocking layer can be disposed above the light-emitting layer. The triplet state (T1) energy level of the hole-blocking layer material is higher than the T1 energy level of the main material of the light-emitting layer, thereby preventing energy loss from the light-emitting layer material. The HOMO energy level of the material is lower than the HOMO energy level of the main material of the light-emitting layer, thereby acting as a hole-blocking layer. Furthermore, the hole-blocking layer material is required to have suitable electron mobility to facilitate electron transport and reduce device power consumption. Hole-blocking layer materials that meet these conditions are the compounds described above in the present invention.

[0129] The thickness of the hole blocking layer of the present invention may be 2-200 nm, preferably 5-150 nm, and more preferably 5-50 nm, but the thickness is not limited to this range.

[0130] The electron transport layer can be provided above the hole blocking layer. The electron transport layer material is a material that readily accepts electrons from the cathode and transfers the received electrons to the light-emitting layer. Preferably, the material has a high electron mobility. As the electron transport layer of the organic electroluminescent device of the present invention, the following compounds disclosed in the prior art can be used as electron transport layer materials for organic electroluminescent devices:

[0131]

[0132] In a preferred embodiment of the present invention, the electron transport layer further comprises other compounds conventionally used in electron transport layers, for example, Alq3, Liq, preferably Liq.

[0133] The thickness of the electron transport layer of the present invention may be 10-80 nm, preferably 20-60 nm, and more preferably 25-45 nm.

[0134] According to the present invention, an electron injection layer can be provided between the electron transport layer and the cathode. The electron injection layer material is typically preferably a material having a low work function, allowing electrons to be easily injected into the organic functional material layer. Preferably, the electron injection layer material is an N-type metal material. As the electron injection layer material for the organic electroluminescent device of the present invention, the following electron injection layer materials disclosed in the prior art for organic electroluminescent devices can be used: LiF, Cs2CO3, CsF, Csq, NaF, MgF2, CaF2, Al2O3, and Yb.

[0135] The thickness of the electron injection layer of the present invention may be 0.1-5 nm, preferably 0.5-3 nm, and more preferably 0.8-1.5 nm, but the thickness is not limited to this range.

[0136] According to the present invention, as mentioned above, the second electrode can be a cathode or an anode. In the present invention, the second electrode is used as a cathode. The material for forming the cathode can be a material with a low work function, such as a metal, an alloy, a conductive compound or a mixture thereof. Non-limiting examples of cathode materials can include lithium (Li), ytterbium (Yb), magnesium (Mg), aluminum (Al), calcium (Ca), and aluminum-lithium (Al-Li), magnesium-indium (Mg-In) and magnesium-silver (Mg-Ag). The thickness of the cathode depends on the material used, typically 5-100nm, preferably 7-50nm, and more preferably 10-25nm.

[0137] Optionally, to improve the light extraction efficiency of the organic electroluminescent device, a light extraction layer (i.e., CPL layer) may be added on top of the second electrode (i.e., cathode) of the device. The following compounds disclosed in the prior art may be used as the light extraction layer material.

[0138]

[0139]

[0140] The thickness of the light extraction layer is generally 5 to 300 nm, preferably 20 to 100 nm, and more preferably 40 to 80 nm.

[0141] The organic electroluminescent device may further include an encapsulation structure. This encapsulation structure may be a protective structure that prevents foreign substances, such as moisture and oxygen, from entering the organic layer of the organic electroluminescent device. The encapsulation structure may be, for example, a can, such as a glass or metal can, or a thin film covering the entire surface of the organic layer.

[0142] Method for preparing organic electroluminescent device

[0143] The present invention also relates to a method for preparing the above-mentioned organic electroluminescent device, which comprises sequentially laminating a first electrode, an organic thin film layer, and a second electrode on a substrate. The organic thin film layer is formed by sequentially laminating a hole transport region thin film layer, a light emitting region thin film layer, and an electron transport region thin film layer on the first electrode from bottom to top. The hole transport region thin film layer is formed by sequentially laminating a hole injection layer, a hole transport layer, and an electron blocking layer on the first electrode from bottom to top. The electron transport region thin film layer is formed by sequentially laminating a hole blocking layer, an electron transport layer, and an electron injection layer on the light emitting layer from bottom to top. Optionally, a light extraction layer may be laminated on the second electrode to improve the light extraction efficiency of the organic electroluminescent device.

[0144] Regarding lamination, vacuum deposition, vacuum evaporation, spin coating, casting, LB method, inkjet printing, laser printing or LITI method can be used, but are not limited thereto. Vacuum evaporation means heating and coating a material on a substrate in a vacuum environment.

[0145] In the present invention, it is preferred to use a vacuum evaporation method to form the various layers, wherein the layers can be formed at a temperature of about 100-500°C with a temperature of about 10 -8 -10 -2 Torr vacuum and about The vacuum evaporation is carried out at a rate of -6 -10 -2 Torr, more preferably 10 -5 -10 -3 Torr. The rate is about More preferably, about

[0146] In addition, it should be noted that the materials used to form each layer described in the present invention can be formed into a film alone and used as a single layer, or can be mixed with other materials to form a film and used as a single layer. It can also be a stacked structure between layers formed into films alone, a stacked structure between layers formed into films after mixing, or a stacked structure between layers formed into films alone and layers formed into films after mixing.

[0147] The following examples are intended to better explain the present invention, but the scope of the present invention is not limited thereto.

[0148] Example

[0149] I. Compound Preparation Examples

[0150] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0151] The raw materials involved in the synthesis examples of the present invention can be purchased from the market or prepared by conventional preparation methods in the art.

[0152] Synthesis of intermediate B-1:

[0153]

[0154] Preparation of intermediate B-1: Under nitrogen protection, in a round-bottom flask, raw material A-24 (1.85 g, 6 mmol), raw material A-25 (1.16 g, 6.5 mmol), K2CO3 (2.49 g, 18 mmol), tetrahydrofuran (100 mL), and water (50 mL) were added in sequence, and nitrogen was passed through for 30 minutes to replace the air. Pd(PPh3)4 (0.12 g, 0.1 mmol) was added, and the mixture was heated to reflux for 10 hours under nitrogen protection. TLC analysis of the reaction solution revealed complete reaction of the starting material A-24. After completion of the reaction, the reaction system was naturally cooled to room temperature, the solvent was removed by rotary evaporation, and the residue was dissolved in 100 ml of dichloromethane, washed with 150 ml of water, poured into a separatory funnel, shaken, and allowed to stand for separation. After separation, the aqueous phase was extracted with dichloromethane (25 ml x 4). The organic phases were combined, dried over anhydrous magnesium sulfate, and filtered. The filtrate was rotary evaporated to remove dichloromethane to obtain a crude product, which was then purified by silica gel column chromatography to obtain intermediate B-1. LC-MS: Measured value: 361.25 ([M+H]+), theoretical value: 360.16.

[0155] Synthesis of intermediate B-2:

[0156]

[0157] Preparation of Intermediate B-2: Under nitrogen, to a round-bottom flask were added Intermediate B-1 (2.17 g, 6 mmol), starting material A-5 (1.65 g, 6.5 mmol), KOAC (1.77 g, 18 mmol), and dioxane (100 mL). The mixture was purged with nitrogen for 30 minutes to displace the air. Pd(PPh3)4 (0.12 g, 0.1 mmol) was then added, and the mixture was heated under reflux for 24 hours. TLC analysis of the reaction solution confirmed the complete reaction of Intermediate B-1. After completion of the reaction, the reaction system was cooled to room temperature, poured into a separatory funnel, shaken, and allowed to stand for separation. The aqueous phase was extracted with dichloromethane (25 ml x 4). The combined organic phases were dried over anhydrous magnesium sulfate and filtered. The filtrate was rotary evaporated to remove dichloromethane to obtain Intermediate B-2. LC-MS: Measured value: 453.33 ([M+H]+), theoretical value: 452.29.

[0158] Synthesis of intermediate B-3:

[0159]

[0160] Preparation of Intermediate B-3: Refer to the preparation of Intermediate B-1, except that starting material A-24 is replaced by starting material A-26. LC-MS: Found: 361.07 ([M+H]+), Required: 360.16.

[0161] Synthesis of intermediate B-4:

[0162]

[0163] Preparation of Intermediate B-4: Refer to the preparation of Intermediate B-2, except that Intermediate B-1 is replaced by Intermediate B-3. LC-MS: Found: 453.10 ([M+H]+), Required: 452.29.

[0164] Example 1: Synthesis of Compound 3:

[0165]

[0166] Preparation of compound 3: Refer to the preparation of intermediate B-1, except that raw material A-1 is used to replace raw material A-25, and raw material A-24 is used to replace intermediate B-1.

[0167] Example 2: Synthesis of Compound 5:

[0168]

[0169] Preparation of intermediate G-2: In a round-bottom flask, intermediate B-2 (2.94 g, 6.5 mmol), raw material A-3 (2.15 g, 6 mmol), K2CO3 (2.49 g, 18 mmol), tetrahydrofuran (100 mL), and water (50 mL) were added in sequence, and nitrogen was passed through for 30 minutes to replace the air. Palladium acetate (0.022 g, 0.1 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (0.095 g, 0.2 mmol) were added, and the mixture was heated to reflux under nitrogen protection for 15 hours. TLC analysis of the reaction solution revealed complete reaction of the raw material A-3. After completion of the reaction, the reaction system was naturally cooled to room temperature, the solvent was removed by rotary evaporation, and the residue was dissolved in 100 ml of dichloromethane, washed with 50 ml of water, poured into a separatory funnel, shaken, and allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (50 ml x 3). The organic phases were combined, dried over anhydrous magnesium sulfate, and filtered. The filtrate was rotary evaporated to remove dichloromethane to obtain a crude product, which was purified by silica gel column chromatography to obtain intermediate G-2. LC-MS: Measured value: 557.04 ([M+H]+), theoretical value: 556.18.

[0170] Preparation of compound 5: Refer to the preparation of intermediate B-1, except that raw material A-2 is used instead of raw material A-25, and intermediate G-2 is used instead of raw material A-24.

[0171] Example 3: Synthesis of Compound 7:

[0172]

[0173] Preparation of Intermediate G-3: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-4 is used instead of starting material A-24. LC-MS: Measured value: 464.20 ([M+H]+), theoretical value: 463.07.

[0174] Preparation of compound 7: Refer to the preparation of intermediate G-2, except that intermediate G-3 is used to replace raw material A-3.

[0175] Example 4: Synthesis of Compound 9:

[0176]

[0177] Preparation of compound 9: Refer to the preparation of intermediate G-2, except that raw material A-28 is used instead of raw material A-3.

[0178] Example 5: Synthesis of Compound 12:

[0179]

[0180] Preparation of Intermediate G-5: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-3 is used instead of starting material A-24. LC-MS: Measured value: 464.15 ([M+H]+), theoretical value: 463.07.

[0181] Preparation of compound 12: Refer to the preparation of intermediate G-2, except that intermediate G-5 is used to replace raw material A-3.

[0182] Example 6: Synthesis of Compound 13:

[0183]

[0184] Preparation of Intermediate G-6: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-8 is used instead of starting material A-24. LC-MS: Measured value: 464.22 ([M+H]+), theoretical value: 463.07.

[0185] Preparation of compound 13: Refer to the preparation of intermediate G-2, except that intermediate G-6 is used to replace raw material A-3.

[0186] Example 7: Synthesis of Compound 14:

[0187]

[0188] Preparation of compound 14: Refer to the preparation of intermediate G-2, except that raw material A-9 is used instead of raw material A-3.

[0189] Example 8: Synthesis of Compound 21:

[0190]

[0191] Preparation of Intermediate G-8: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-10 is used instead of starting material A-24. LC-MS: Found: 464.14 ([M+H]+), Required: 463.07.

[0192] Preparation of compound 21: Refer to the preparation of intermediate G-2, except that intermediate G-8 is used to replace raw material A-3.

[0193] Example 9: Synthesis of Compound 53:

[0194]

[0195] Preparation of Intermediate G-9: Refer to the preparation of Intermediate B-1, except that starting material A-1 is used instead of starting material A-25, and starting material A-11 is used instead of starting material A-24. LC-MS: Measured value: 540.27 ([M+H]+), theoretical value: 539.10.

[0196] Preparation of compound 53: Refer to the preparation of intermediate G-2, except that intermediate G-9 is used to replace raw material A-3.

[0197] Example 10: Synthesis of Compound 71:

[0198]

[0199] Preparation of Intermediate G-10: Refer to the preparation of Intermediate B-1, except that starting material A-13 is used instead of starting material A-25, and starting material A-12 is used instead of starting material A-24. LC-MS: Found: 540.04 ([M+H]+), Required: 539.10.

[0200] Preparation of compound 71: Refer to the preparation of intermediate G-2, except that intermediate G-10 is used to replace starting material A-3.

[0201] Example 11: Synthesis of Compound 105:

[0202]

[0203] Preparation of Intermediate G-11: Refer to the preparation of Intermediate B-1, except that starting material A-17 is used instead of starting material A-25, and starting material A-3 is used instead of starting material A-24. LC-MS: Measured value: 540.38 ([M+H]+), theoretical value: 539.10.

[0204] Preparation of compound 105: Refer to the preparation of intermediate G-2, except that intermediate G-11 is used to replace starting material A-3.

[0205] Example 12: Synthesis of Compound 113:

[0206]

[0207] Preparation of Intermediate G-12: Refer to the preparation of Intermediate B-1, except that starting material A-18 is used instead of starting material A-25, and starting material A-24 is used instead of intermediate G-3. LC-MS: Found: 496.22 ([M+H]+), Required: 495.15.

[0208] Preparation of compound 113: Refer to the preparation of intermediate G-2, except that intermediate G-12 is used to replace raw material A-3.

[0209] Example 13: Synthesis of Compound 114:

[0210]

[0211] Preparation of Intermediate G-13: Refer to the preparation of Intermediate B-1, except that starting material A-18 is used instead of starting material A-25, and starting material A-24 is used instead of intermediate G-6. LC-MS: Found: 496.08 ([M+H]+), Required: 495.15.

[0212] Preparation of compound 114: Refer to the preparation of intermediate G-2, except that intermediate G-13 is used to replace starting material A-3.

[0213] Example 14: Synthesis of Compound 143:

[0214]

[0215] Preparation of Intermediate G-14: Refer to the preparation of Intermediate G-2, except that starting material A-3 is replaced by starting material A-19. LC-MS: Measured value: 531.06 ([M+H]+), theoretical value: 530.16.

[0216] Preparation of compound 143: Refer to the preparation of intermediate B-1, except that starting material A-13 is used instead of starting material A-25, and intermediate G-14 is used instead of starting material A-24.

[0217] Example 15: Synthesis of Compound 179:

[0218]

[0219] Preparation of Intermediate G-15: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-14 is used instead of starting material A-24. LC-MS: Found: 422.06 ([M+H]+), Required: 421.00.

[0220] Preparation of intermediate H-15: Refer to the preparation of intermediate G-2, except that intermediate G-15 is used instead of raw material A-3. LC-MS: Measured value: 668.39 ([M+H]+), theoretical value: 667.28.

[0221] Preparation of compound 179: Refer to the preparation of intermediate B-1, except that starting material A-20 is used instead of starting material A-25, and intermediate H-15 is used instead of starting material A-24.

[0222] Example 16: Synthesis of Compound 203:

[0223]

[0224] Preparation of Intermediate G-16: Refer to the preparation of Intermediate B-1, except that starting material A-1 is used instead of starting material A-25, and starting material A-21 is used instead of starting material A-24. LC-MS: Found: 514.20 ([M+H]+), Required: 513.08.

[0225] Preparation of compound 203: Refer to the preparation of intermediate G-2, except that intermediate G-16 is used to replace starting material A-3.

[0226] Example 17: Synthesis of Compound 258:

[0227]

[0228] Preparation of Intermediate G-17: Refer to the preparation of Intermediate B-1, except that starting material A-2 is used instead of starting material A-25, and starting material A-22 is used instead of starting material A-24. LC-MS: Found: 434.04 ([M+H]+), Required: 433.10.

[0229] Preparation of compound 258: Refer to the preparation of intermediate G-2, except that intermediate G-17 is used to replace starting material A-3.

[0230] Example 18: Synthesis of Compound 337:

[0231]

[0232] Preparation of compound 337: Refer to the preparation of intermediate B-1, except that starting material A-27 is used instead of starting material A-25, and intermediate B-3 is used instead of starting material A-24.

[0233] Example 19: Synthesis of Compound 340:

[0234]

[0235] Preparation of compound 340: Refer to the preparation of intermediate G-2, except that intermediate G-3 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0236] Example 20: Synthesis of Compound 342:

[0237]

[0238] Preparation of compound 342: Refer to the preparation of intermediate G-2, except that raw material A-28 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0239] Example 21: Synthesis of Compound 346:

[0240]

[0241] Preparation of compound 346: Refer to the preparation of intermediate G-2, except that intermediate G-6 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0242] Example 22: Synthesis of Compound 347:

[0243]

[0244] Preparation of compound 347: Refer to the preparation of intermediate G-2, except that raw material A-9 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0245] Example 23: Synthesis of Compound 438:

[0246]

[0247] Preparation of compound 438: Refer to the preparation of intermediate G-2, except that intermediate G-11 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0248] Example 24: Synthesis of Compound 446:

[0249]

[0250] Preparation of compound 446: Refer to the preparation of intermediate G-2, except that intermediate G-12 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0251] Example 25: Synthesis of Compound 447:

[0252]

[0253] Preparation of compound 447: Refer to the preparation of intermediate G-2, except that intermediate G-13 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0254] Example 26: Synthesis of Compound 536:

[0255]

[0256] Preparation of compound 536: Refer to the preparation of intermediate G-2, except that intermediate G-16 is used to replace raw material A-3, and intermediate B-4 is used to replace intermediate B-2.

[0257] The structural characteristics of the compounds obtained in each example are shown in Table 1:

[0258] Table 1

[0259]

[0260]

[0261]

[0262] II. Device Preparation Example

[0263] The following describes in detail the effects of using the compounds synthesized according to the present invention as hole-blocking layer materials in devices using Device Examples 1-38 and Comparative Examples 1-13. Compared to Comparative Example 1, the devices in Device Examples 1-38 and Comparative Examples 2-13 utilize identical fabrication processes, identical substrate materials, and identical electrode materials, with the same electrode material thicknesses. The only difference is that the hole-blocking layer materials used in the devices are modified. The device layer structures are shown in Table 2, and the performance test results for each device are shown in Table 3.

[0264] The molecular structure formula of the relevant materials is shown below:

[0265]

[0266]

[0267] The structures of comparative compounds HB-1, HB-2, HB-3, HB-4, HB-5, HB-6, HB-7, HB-8, HB-9, HB-10, HB-11, HB-12, and HB-13 are shown above. The above materials are commercially available or can be obtained by conventional preparation methods in the art.

[0268] Device Comparative Example 1

[0269] The specific preparation process is as follows:

[0270] like Figure 1 As shown, the transparent substrate layer 1 is made of transparent glass. Ag (100 nm) is evaporated as the anode layer 2. On the anode layer 2, HT-1 and P-1 are evaporated to a thickness of 10 nm as the hole injection layer 3 using a vacuum evaporation apparatus. The weight ratio of HT-1 to P-1 is 97:3. HT-1 is then evaporated to a thickness of 130 nm as the hole transport layer 4. EB-1 is then evaporated to a thickness of 5 nm as the electron blocking layer 5. After the deposition of these electron blocking materials, the light-emitting layer 6 of the OLED light-emitting device is formed. BH-1 is used as the host material and BD-1 as the dopant material. The dopant ratio is 3% by weight, and the thickness of light-emitting layer 6 is 20 nm. Following this light-emitting layer 6, HB-1 is evaporated to a thickness of 5 nm as the hole blocking layer 7. ET-1 and Liq are then evaporated on top of this hole blocking layer 7. The weight ratio of ET-1 to Liq is 1:1. The vacuum-evaporated film thickness of this material was 30 nm, and this layer served as electron transport layer 8. A 1 nm thick LiF layer was formed on electron transport layer 8 using a vacuum evaporation device. This layer served as electron injection layer 9. A 16 nm thick Mg:Ag electrode layer (Mg:Ag mass ratio of 1:9) was formed on electron injection layer 9 using a vacuum evaporation device. This layer served as cathode layer 10. On cathode layer 10, 65 nm of CP-1 was vacuum-evaporated to serve as light extraction layer 11.

[0271] Device Examples 1-38 and Device Comparative Examples 2-13 were prepared in a similar manner to Device Comparative Example 1, except that the hole blocking layer materials listed in Table 2 below were used.

[0272] Table 2

[0273]

[0274]

[0275]

[0276]

[0277] III. Device Testing Example

[0278] The device prepared in step II was tested for its current efficiency, CIEy, and LT95 life. The current efficiency and CIEy were tested using an IVL (current-voltage-luminance) test system (Suzhou Fushida Scientific Instrument Co., Ltd.) at a current density of 10 mA / cm 2 LT95 refers to the time it takes for the device's brightness to decay to 95% of its initial brightness. The current density during the test is 30mA / cm 2 The life test system is the EAS-62C OLED device life tester produced by Japan System Engineering Co., Ltd. The test results are shown in Table 3 below.

[0279] Table 3

[0280]

[0281]

[0282]

[0283]

[0284] It can be seen from the device test data results in Table 3 above that, compared with the control devices using HB-1 to HB-13 as hole blocking layer materials, the devices prepared using the compounds of the present invention as hole blocking layer materials have improved current efficiency and extended device life.

[0285] The above description is only a preferred embodiment 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 in the scope of protection of the present invention.

Claims

1. A compound containing a nitrogen-containing heterobenzene structure, characterized in that The structure of the compound is shown in general formula (1): In the general formula (1), Z1, Z2, and Z3 are each independently represented by CH or N; at least one of Z1, Z2, and Z3 is represented by N; Z1, Z2, and Z3 may be the same or different; Ar1 and Ar2 are each independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted carbazolyl group; Ar1 ​​and Ar2 may be the same or different; L1 and L2 each independently represent a single bond, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted pyridylene group; L1 and L2 may be the same or different; R represents the structure shown in general formula (2); The asterisk * in the general formula (2) indicates the connection position between the general formula (2) and L2; In the general formula (2), R1, R2, R3, R4, and R5 are each independently any one of a hydrogen atom, a C1-C20 alkyl group, and a C3-C20 cycloalkyl group; at least one of R1, R2, R3, R4, and R5 is not a hydrogen atom, and R1, R2, R3, R4, and R5 may be the same or different; The substituents for the above-mentioned substitutable groups are selected from deuterium atoms, C1-C20 alkyl groups, C3-C20 cycloalkyl groups, cyano groups, phenyl groups, naphthyl groups, biphenyl groups, terphenyl groups, pyridyl groups, pyrimidyl groups, phenanthrenyl groups, dibenzofuranyl groups, dibenzothiophenyl groups or carbazolyl groups; The general formula (1) does not represent the structure shown in the general formula (3); 2. A compound containing a nitrogen-containing heterobenzene structure according to claim 1, characterized in that The structure of the compound is shown in any one of the general formulas (2-1) to (2-4): In general formula (2-1) to general formula (2-4), the meanings of Z1, Z2, Z3, Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 are the same as those defined in claim 1.

3. A compound containing nitrogen-heterobenzene structure according to claim 1, characterized in that, The structure of the compound is shown in any one of the general formulas (3-1) to (3-5): In general formula (3-1) to general formula (3-5), the meanings of Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 are the same as those defined in claim 1.

4. The compound containing nitrogen-containing heterobenzene structure according to claim 1, characterized in that The structure of the compound is shown in any one of the general formulas (4-1) to (4-4): In general formula (4-1) to general formula (4-4), the meanings of Z1, Z2, Z3, Ar1, Ar2, L1, L2, R1, R2, R3, R4, and R5 are the same as those defined in claim 1.

5. The compound containing nitrogen-containing heterobenzene structure according to claim 1, characterized in that: The structure of the compound is shown in any one of the general formulas (5-1) to (5-42): In general formula (5-1) to general formula (5-42), the meanings of Z1, Z2, Z3, Ar1, Ar2, and R are the same as those defined in claim 1.

6. The compound containing nitrogen-heterobenzene structure according to claim 1, characterized in that: Any hydrogen atoms in the compound represented by the general formula (1) may be partially or completely replaced by deuterium atoms.

7. The compound containing nitrogen-heterobenzene structure according to claim 1, characterized in that: The specific structure of the compound is any one of the following structures:

8. An organic electroluminescent device comprising, in order, a substrate, a first electrode, an organic thin film layer, and a second electrode, characterized in that: The organic thin film layer contains the compound containing nitrogen-containing heterobenzene structure according to any one of claims 1 to 7; Preferably, the organic thin film layer includes a hole transport region thin film layer, a light emitting region thin film layer and an electron transport region thin film layer, and the electron transport region thin film layer contains the nitrogen-containing heterobenzene structure compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, characterized in that: The electron transport region thin film layer comprises a hole blocking layer, and the hole blocking layer contains the nitrogen-containing heterobenzene structure compound according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 8, characterized in that: The electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the nitrogen-containing heterobenzene structure compound according to any one of claims 1 to 7.

11. The electroluminescent device according to claim 8, characterized in that: The hole transport region thin film layer comprises a hole injection layer, a hole transport layer and an electron blocking layer, the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the nitrogen-containing heterobenzene structure compound according to any one of claims 1 to 7.

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