A compound containing a naphtho-five-membered oxygen-containing heterocyclic structure and an organic electroluminescent device containing the same

Abstract

The invention discloses a compound containing a naphtho-pentacyclic oxygen-containing heterocyclic structure and an organic electroluminescent device containing the same, and belongs to the field of semiconductor technology. The structure of the monoaromatic amine compound of the naphtho-pentacyclic oxygen-containing heterocyclic structure of the invention is as described in general formula (1), and the compound of the invention contains a naphtho-pentacyclic oxygen-containing heterocyclic structure and is combined with a phenanthrene-containing group or a fluorene-containing group, which improves the rigidity of the molecule as a whole, so that the structural type has a higher glass transition temperature, excellent film phase stability and excellent high temperature weather resistance, and the group molecules contained in the compound have good conjugation and planarity, so that the compound of the invention has excellent hole migration ability, and is applied to an organic electroluminescent device, has a strong hole injection and transmission ability and a suitable energy level, and holes can be effectively transmitted and injected into the light-emitting layer, so that the organic electroluminescent device can achieve high-efficiency luminescence under a low driving voltage.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, in particular to a compound containing a naphtho-five-membered oxygen-containing heterocyclic structure and an organic electroluminescent device containing the compound. Background Art

[0002] The carriers (holes and electrons) in an organic electroluminescent device (OLED) are injected into the device by the two electrodes of the device under the drive of an electric field, and meet in the organic light-emitting layer to recombine and emit light. High-performance organic electroluminescent devices require various organic functional materials to have good photoelectric properties. For example, as a charge transport material, it is required to have good carrier mobility. The injection and transport properties of the hole injection layer materials and hole transport layer materials used in existing organic electroluminescent devices are relatively weak, and the hole injection and transport rates do not match the electron injection and transport rates, resulting in a large offset in the recombination area, which is not conducive to the stability of the device. In addition, the reasonable energy level matching of the hole injection layer material and the hole transport layer material is an important factor in improving the efficiency and life of the device. Therefore, how to adjust the balance of holes and electrons and adjust the recombination area has always been an important topic in this field.

[0003] Blue organic electroluminescent devices have always been the weak point in the development of full-color OLEDs. Up to now, the efficiency and life of blue light devices have been difficult to be comprehensively improved. Therefore, how to improve the performance of such devices is still a crucial issue and challenge facing this field. Most of the blue light host materials currently used in the market are electron-biased hosts. Therefore, in order to adjust the carrier balance of the light-emitting layer, the hole transport material needs to have excellent hole transport performance. The better the hole injection and transport, the more the recombination area will be adjusted to shift away from the electron blocking layer, thereby emitting light away from the interface, improving the device performance and increasing the life. Therefore, the hole transport area material is required to have high hole injectivity, high hole mobility, high electron blocking property and high electron weather resistance.

[0004] Because hole transport materials have a thicker film thickness, the heat resistance and amorphousness of the material will have a crucial impact on the life of the device. Materials with poor heat resistance are prone to decomposition during the evaporation process, polluting the evaporation cavity and damaging the life of the device; materials with poor film phase stability will crystallize during the use of the device, reducing the service life of the device. Therefore, hole transport materials are required to have higher film phase stability and decomposition temperature during use. However, the development of materials for stable and effective organic material layers for organic electroluminescent devices has not yet been fully realized. Therefore, it is necessary to continuously develop a new material to better meet the performance requirements of organic electroluminescent devices. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a monoaromatic amine compound containing a naphtho-pentacyclic oxygen-containing heterocyclic structure and an organic electroluminescent device containing the same. The compound of the present invention contains a naphtho-pentacyclic oxygen-containing heterocyclic structure and is combined with a phenanthrene-containing group or a fluorene-containing group, which improves the rigidity of the molecule as a whole, so that this type of structure has a higher glass transition temperature and excellent high-temperature weather resistance, and has excellent hole migration ability. When applied to an organic electroluminescent device, it has a strong hole injection and transmission ability and a suitable energy level, holes can be effectively transmitted and injected into the light-emitting layer, and high-efficiency light emission under a low driving voltage of the organic electroluminescent device can be achieved.

[0006] The technical solution of the present invention is as follows:

[0007] A compound containing a naphtho-five-membered oxygen-containing heterocyclic structure, wherein the compound structure is shown in the general formula (1):

[0008]

[0009] In the general formula (1), Z1 and Z2 are independently represented by CR;

[0010] The L, L1, and L2 are independently represented by a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted biphenylene group;

[0011] Ar1 and Ar2 are independently represented by substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted furanyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted indenyl, substituted or unsubstituted piperonyl, or a structure represented by the general formula (2), the general formula (3) or the general formula (4); and at least one of Ar1 and Ar2 is represented by a structure represented by the general formula (2), the general formula (3) or the general formula (4); and when Ar1 is represented by a structure represented by the general formula (3), the side chains represented by L2 and Ar2 cannot be phenyl;

[0012]

[0013] In the general formula (3), Ra and Rb are independently methyl, phenyl or naphthyl;

[0014] R, R1, and R2 are independently represented by hydrogen atom, deuterium atom, methyl, ethyl, tert-butyl, adamantyl, phenyl, naphthyl or biphenyl;

[0015] R3 is a hydrogen atom, a deuterium atom, a methyl group, an ethyl group, a tert-butyl group, an adamantyl group, a phenyl group, a naphthyl group or a biphenyl group, and when R3 is a phenyl group or a naphthyl group, a and b, b and c or c and d can form a ring with the general formula (3);

[0016] The R4 represents a hydrogen atom, a phenyl group, a naphthyl group or a biphenyl group;

[0017] The L3 represents a single bond, a phenylene group, a naphthylene group or a biphenylene group;

[0018] The substituent of the "substituted or unsubstituted" group is selected from one or more of a deuterium atom, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, a naphthyl group, a biphenyl group, a benzofuranyl group, a dibenzofuranyl group, a thienyl group, a benzothienyl group, and a dibenzothienyl group.

[0019] In a preferred embodiment, the compound structure is shown in general formula (5):

[0020]

[0021] In the general formula (5), L represents a phenylene group or a naphthylene group, and L1 and L2 each independently represent a single bond, a phenylene group, a naphthylene group or a biphenylene group;

[0022] The definitions of Ar1, Ar2, R1 and Z2 are as described above.

[0023] In a preferred embodiment, the compound structure is as shown in general formula (6-1) or general formula (6-2):

[0024]

[0025] In the general formula (6-1) and the general formula (6-2), L is a phenylene group or a naphthylene group, L1 and L2 are independently represented by a single bond, a phenylene group, a naphthylene group or a biphenylene group; the definitions of Ar1 and Ar2 are as described above.

[0026] In a preferred embodiment, the compound structure is as shown in general formula (7-1) or general formula (7-2):

[0027]

[0028] In the general formula (7-1) and the general formula (7-2), the connection site between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*;

[0029] The L is a phenylene group or a naphthylene group, L1 and L2 are independently represented by a single bond, a phenylene group, a naphthylene group or a biphenylene group; the definitions of Ar1, Z1, Z2, Ra and Rb are as described above.

[0030] In a preferred embodiment, the compound structure is as shown in the general formula (8-1) or the general formula (8-2):

[0031]

[0032] In the general formula (8-1) and the general formula (8-2), the definitions of L1, L2, Ar1, and Ar2 are as described above.

[0033] In a preferred embodiment, the compound structure is as shown in general formula (9-1) to general formula (9-3):

[0034]

[0035] In general formula (9-1) to general formula (9-3), the connection site between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*;

[0036] The definitions of L, L1, L2, Ar1, Z1, Z2, Ra and Rb are as described above.

[0037] In a preferred embodiment, the compound structure is as shown in general formula (10-1) to general formula (10-2):

[0038]

[0039] In the general formula (10-1) to the general formula (10-2), R0 represents one of a deuterium atom, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, a naphthyl group, a biphenyl group, a benzofuranyl group, and a dibenzofuranyl group.

[0040] The connection point between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*;

[0041] The definitions of L, L2, Ar1, Z1, Z2, Ra, Rb and R2 are as described above.

[0042] In a preferred embodiment, the compound structure is shown in the general formula (11-1):

[0043]

[0044] In the general formula (11-1), R0 represents one of a deuterium atom, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, a naphthyl group, a biphenyl group, a benzofuranyl group, and a dibenzofuranyl group.

[0045] The connection point between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*;

[0046] The definitions of L, L2, Ar1, Z1, Z2, Ra, Rb and R2 are as described above.

[0047] In a preferred embodiment, the specific structure of the compound is any one of the following structures:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] The present invention also provides an organic electroluminescent device, which comprises an anode, a hole transport region, a light emitting region, an electron transport region and a cathode in sequence, wherein the hole transport region comprises the compound containing a naphtho-five-membered oxygen-containing heterocyclic structure;

[0058] Preferably, the hole transport region comprises a hole injection layer, a first hole transport layer and an electron blocking layer.

[0059] More preferably, the first hole transport layer and the hole injection layer contain the naphtho-five-membered oxygen-containing heterocyclic structure-containing compound;

[0060] More preferably, the first hole transport layer is composed of the compound containing a naphtho-five-membered oxygen-containing heterocyclic structure, and the hole injection layer is composed of the compound containing a naphtho-five-membered oxygen-containing heterocyclic structure and other doping materials conventionally used for the hole injection layer.

[0061] In a preferred embodiment, the electron transport region comprises a nitrogen heterocyclic compound represented by the following general formula (10):

[0062]

[0063] In the general formula (10), Ar3, Ar4, and Ar5 are independently substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C2-C 30 One of the heterocyclic groups;

[0064] L0 is selected from a single bond, a substituted or unsubstituted C6-C 30Arylene, substituted or unsubstituted C2-C 30 A heterocyclylene group;

[0065] X1, X2, and X3 independently represent N or CH, and at least one of X1, X2, and X3 represents N;

[0066] The substituents for the substituent groups are selected from deuterium, tritium, C 1-10 Alkyl, C6-C 30 The invention further comprises one or more of an aryl group, a C2-C30 heteroaryl group containing one or more heteroatoms; the heteroatoms are selected from N, O or S.

[0067] In a preferred embodiment, the electron transport region comprises an electron transport layer and an electron injection layer, wherein the electron transport layer comprises a nitrogen heterocyclic compound represented by the general formula (10); and the electron injection layer is an N-type metal material.

[0068] The beneficial technical effects of the present invention are:

[0069] The compound provided by the present invention contains a naphtho-five-membered oxygen-containing heterocyclic structure and is combined with a phenanthrene-containing group or a fluorene-containing group. This combination makes the compound of the present invention have the following advantages:

[0070] (1) It is well known in the art that for hole transport materials, the higher the degree of delocalization of HOMO on the entire molecule, the easier it is for holes to be transported between molecules, and thus it is easy to obtain a higher hole carrier conduction efficiency. Based on the in-depth research of the inventors, the combination of the features of the present invention is more conducive to the distribution of HOMO on the entire molecule, thereby making it easy to obtain a high carrier mobility of the material, and thus it is easy to obtain a long life effect of the device.

[0071] (2) Since the naphthoxy-pentacyclic oxygen-containing heterocyclic structure has a high degree of conjugation, compounds containing this structure have a narrow band gap (Eg). However, the combination method of the present invention can effectively avoid this problem and make the compounds of the present invention have a relatively wide band gap.

[0072] (3) This combination improves the rigidity of the molecule as a whole, so that this type of structure has a higher glass transition temperature, excellent film phase stability and excellent high-temperature weather resistance. In addition, the combination of specific groups of the present invention is conducive to lowering the evaporation temperature of the molecule. In other words, even if the molecular weight of the structure is relatively high, it can ensure a lower evaporation temperature. This excellent performance is not only conducive to the thermal evaporation of the material, but also controls the thermal decomposition rate of the material, thereby improving the stability of the material in device applications.

[0073] The organic functional materials constituting the OLED device not only include hole injection conductive materials but also include electron injection conductive materials and light-emitting layer materials. Good device application effects require good carrier balance as a guarantee. Therefore, in order to obtain the best device application effects, the compounds matching the characteristic structures of the present invention also require specific electronic materials for matching. Based on the in-depth research of the inventors, the electronic materials are preferably materials containing azabenzene structural characteristics, such as triazine materials, pyridine materials, pyrazine materials, etc. or derivatives containing these characteristic groups. The compounds of the present invention are combined with azabenzene ring electron transport materials to make it easy for electrons and holes to obtain the best equilibrium state, and have excellent lifespan while having high efficiency, and are particularly easy to obtain good device high temperature life effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a cross-sectional schematic diagram of the organic electroluminescent device of the present invention.

[0075] In the figure: 1 is a transparent substrate layer, 2 is an anode layer, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, 10 is a cathode layer, and 11 is a CPL layer. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0078] In the present invention, unless otherwise specified, HOMO means the highest occupied orbital of a molecule, and LUMO means the lowest unoccupied orbital of a molecule. In addition, the "difference in HOMO energy levels" and "difference in LUMO energy levels" referred to in this specification mean the difference in the absolute value of each energy value. In addition, in the present invention, HOMO and LUMO energy levels are expressed in absolute values, and the comparison between energy levels is also a comparison of the absolute values ​​thereof. Those skilled in the art know that the greater the absolute value of an energy level, the lower the energy of the energy level.

[0079] In the present invention, when a layer or element is referred to as being "on" another layer or substrate, the layer or element may be directly on the other layer or substrate, or there may be intervening layers. In addition, it will be understood that when a layer is referred to as being "between" two layers, the layer may be the only layer between the two layers, or there may be one or more intervening layers. The same reference numerals throughout the text represent the same elements.

[0080] In the present invention, when describing electrodes and organic electroluminescent devices, as well as other structures, the words "upper", "lower", "top" and "bottom" used to indicate orientation only indicate the orientation in a certain state, and do not mean that the related structure can only exist in the orientation described; on the contrary, if the structure can change its position, such as inverted, the orientation of the structure will be changed accordingly. Specifically, in the present invention, the "bottom" or "lower" side of the electrode refers to the side of the electrode close to the substrate during the preparation process, and the opposite side away from the substrate is the "top" or "upper" side.

[0081] In this specification, the term "substituted" means that one or more hydrogen atoms on a designated atom or group are replaced by a designated group, provided that the normal valency of the designated atom is not exceeded under the existing circumstances.

[0082] In this specification, the term "C6-C 30 Aryl" or "C6-C 30 "Arylene" refers to a fully unsaturated monocyclic, polycyclic or fused polycyclic (ie, rings which share a pair of adjacent carbon atoms) system having from 6 to 30 ring carbon atoms.

[0083] In this specification, the term "C2-C 30 "Heterocyclyl" refers to a saturated, partially saturated or fully unsaturated cyclic group having 2 to 30 ring carbon atoms and containing at least one heteroatom selected from N, O and S, including but not limited to heteroaryl, heterocycloalkyl, fused ring or a combination thereof. When the heterocyclyl is a fused ring, each ring or all rings of the heterocyclyl may contain at least one heteroatom.

[0084] More specifically, the substituted or unsubstituted C6-C 30 Aryl and / or substituted or unsubstituted C2-C30 The heterocyclic group refers to substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted metaterphenyl, substituted or unsubstituted substituted or unsubstituted triphenylene, substituted or unsubstituted perylene, substituted or unsubstituted indenyl, substituted or unsubstituted furyl, substituted or unsubstituted thienyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted triazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxadiazolyl, substituted or unsubstituted thiadiazolyl, substituted or unsubstituted pyridinyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted naphthyridinyl, substituted or unsubstituted benzoxazinyl, substituted or unsubstituted benzothiazinyl, substituted or unsubstituted acridinyl, substituted or unsubstituted phenazinyl, substituted or unsubstituted phenathiazinyl, substituted or unsubstituted phenoxazinyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazolyl, combinations thereof, or condensed rings of combinations of the foregoing groups, but are not limited thereto.

[0085] In this specification, substituted or unsubstituted C6-C 30 Arylene or substituted or unsubstituted C2-C 30 Heterocyclylene refers to a substituted or unsubstituted C6-C 30 Aryl or substituted or unsubstituted C5-C 30 heterocyclic groups, for example substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted anthrylene, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted tetraphenylene, substituted or unsubstituted pyrenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted metaterphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted triphenylene, substituted or unsubstituted perylene, substituted or unsubstituted indenylene, substituted or unsubstituted furylene, substituted or unsubstituted thienylene, substituted or unsubstituted pyrrolylene, substituted or unsubstituted pyrazolylene, substituted or unsubstituted imidazolylene, substituted or unsubstituted triazolylene, substituted or unsubstituted oxazolylene, substituted or unsubstituted thiazolylene, substituted or unsubstituted oxadiazolylene, substituted or unsubstituted thiadiazolylene, substituted or unsubstituted pyridinylene, substituted or unsubstituted pyrimidinylene, substituted or unsubstituted pyrazinylene, substituted or unsubstituted triazinylene, substituted or unsubstituted benzofuranylene, substituted or unsubstituted benzothiophenylene, substituted or unsubstituted benzimidazolylene, substituted or unsubstituted indolylene, substituted or unsubstituted quinolylene, substituted or unsubstituted isoquinolylene, substituted or unsubstituted quinazolinylene, substituted or unsubstituted quinoxalylene, substituted or unsubstituted naphthyridinylene, substituted or unsubstituted benzoxazinylene, substituted or unsubstituted benzothiazinylene, substituted or unsubstituted acridinylene, substituted or unsubstituted phenazinylene, substituted or unsubstituted phenathiazinylene, substituted or unsubstituted phenoxazinylene, substituted or unsubstituted fluorenylene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted dibenzothiophenylene, substituted or unsubstituted carbazolylene, combinations thereof, or fused rings of combinations of the foregoing groups, but are not limited thereto.

[0086] In this specification, the hole characteristic refers to a characteristic that can donate electrons when an electric field is applied and holes formed in the anode are easily injected into the light-emitting layer and transported in the light-emitting layer due to the conductive characteristic according to the highest occupied molecular orbital (HOMO) level.

[0087] In this specification, the electronic characteristics refer to the characteristics that electrons formed in the cathode can be easily injected into the light-emitting layer and transported in the light-emitting layer due to the conductive characteristics according to the lowest unoccupied molecular orbital (LUMO) level when an electric field is applied.

[0088] Organic electroluminescent devices

[0089] The present invention provides an organic electroluminescent device using a compound having a naphtho-five-membered oxygen-containing heterocyclic structure of general formula (1).

[0090] In an exemplary embodiment of the present invention, the organic electroluminescent device may include an anode, a hole transport region, a light emitting region, an electron transport region, and a cathode.

[0091] 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, without any particular limitation.

[0092] In the organic electroluminescent device of the present invention, any substrate commonly used in organic electroluminescent devices can also be used. Examples thereof are transparent substrates, such as glass or transparent plastic substrates; opaque substrates, such as silicon substrates; flexible polyimide (PI) film substrates. Different substrates have different mechanical strengths, thermal stability, transparency, surface smoothness, and waterproofness. Depending on the properties of the substrate, its use direction is different. In the present invention, a transparent substrate is preferably used. The thickness of the substrate is not particularly limited.

[0093] anode

[0094] Preferably, an anode can be formed on a substrate. In the present invention, the anode and the cathode are opposite to each other. The anode can be made of a conductor with a higher work function to facilitate hole injection, and can be, for example, a metal such as nickel, platinum, copper, zinc, silver or an alloy thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); a combination of a metal and a metal oxide such as ZnO and Al or ITO and Ag; a conductive polymer such as poly(3-methylthiophene), poly(3,4-(ethylene-1,2-dioxy)thiophene) and polyaniline, but not limited thereto. The thickness of the anode depends on the material used, and is typically 50-500nm, preferably 70-300nm, and more preferably 100-200nm. In the present invention, a combination of a metal and a metal oxide, ITO and Ag, is preferably used.

[0095] cathode

[0096] The cathode can be made of a conductor with a lower work function to facilitate electron injection, such as a metal or its alloy, such as magnesium, calcium, sodium, potassium, titanium, indium, aluminum, silver, tin, and combinations thereof; a multilayer structure material, such as LiF / Al, Li2O / Al, and BaF2 / Ca, but not limited thereto. The thickness of the cathode depends on the material used, and is generally 10-50 nm, preferably 15-20 nm.

[0097] Emitting Area

[0098] In the present invention, the light-emitting region may be arranged between the anode and the cathode, and may include at least one host material and at least one guest material. As the host material and the guest material of the light-emitting region of the organic electroluminescent device of the present invention, the light-emitting layer materials for organic electroluminescent devices known in the prior art may be used. The host material may be, for example, a thiazole derivative, a benzimidazole derivative, a polydialkylfluorene derivative or 4,4'-bis(9-carbazolyl)biphenyl (CBP). The host material may use a compound containing an anthracene group. The guest material may be, for example, quinacridone, coumarin, rubrene, perylene and its derivatives, benzopyran derivatives, rhodamine derivatives or aminostyrene derivatives.

[0099] In a preferred embodiment of the present invention, the light emitting region comprises one or two host material compounds.

[0100] In a preferred embodiment of the present invention, the light-emitting region comprises two host material compounds, and the two host material compounds can form an exciplex.

[0101] In a preferred embodiment of the present invention, the host material of the light-emitting region is selected from one or more of the following compounds BH-1 to BH-11:

[0102]

[0103]

[0104] In the present invention, the light-emitting region may contain a phosphorescent or fluorescent guest material to improve the fluorescent or phosphorescent properties of the organic electroluminescent device. Specific examples of phosphorescent guest materials include metal complexes of iridium, platinum, etc. For fluorescent guest materials, those commonly used in the art can be used. In a preferred embodiment of the present invention, the guest material of the light-emitting film layer used is selected from one of the following compounds BD-1 to BD-10:

[0105]

[0106] In the light emitting region of the present invention, the ratio of the host material to the guest material used is 99:1-70:30, preferably 99:1-85:15 and more preferably 97:3-87:13, based on mass.

[0107] The thickness of the light emitting region may be 10-50 nm, preferably 15-30 nm, but the thickness is not limited to this range.

[0108] Hole transport region

[0109] In the organic electroluminescent device of the present invention, the hole transport region is disposed between the anode and the light emitting region, and includes a hole injection layer, a hole transport layer and an electron blocking layer.

[0110] Hole injection layer

[0111] The hole injection material used in the hole injection layer (also called the anode interface buffer layer) is a material that can fully accept holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably a value between the work function of the anode material and the HOMO of the adjacent organic material layer. In a preferred embodiment of the present invention, the hole injection layer is a mixed film layer of a main organic material and a P-type doping material. In order to smoothly inject holes from the anode into the organic film layer, the HOMO energy level of the main organic material must have certain characteristics with the P-type doping material, so that it is expected to realize the occurrence of charge transfer states between the main material and the doping material, and realize the ohmic contact between the hole injection layer and the anode, thereby realizing efficient injection of holes from the electrode to the hole injection layer. This feature is summarized as: the difference between the HOMO energy level of the main material and the LUMO energy level of the P-type doping material is ≤0.4eV. Therefore, for hole-type main materials with different HOMO energy levels, different P-type doping materials need to be selected to match them in order to achieve ohmic contact at the interface and improve the hole injection effect.

[0112] Preferably, the host organic material is a compound containing a naphtho-five-membered oxygen-containing heterocyclic structure.

[0113] Preferably, the P-type doping material is a compound having charge conductivity selected from the following: quinone derivatives or metal oxides, such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0114] In a preferred embodiment of the present invention, the P-type doping material used is selected from any one of the following compounds HI1 to HI8:

[0115]

[0116] In one embodiment of the present invention, the ratio of the host organic material to the P-type doping material used is 99:1-95:5, preferably 99:1-97:3, based on mass.

[0117] In a preferred embodiment of the present invention, the hole injection layer is a mixed film layer of an aromatic amine compound and a P-type doping material, and the aromatic amine compound is a naphtho-pentacyclic oxygen-containing heterocyclic compound of general formula (1).

[0118] The thickness of the hole injection layer of the present invention may be 5-20 nm, preferably 8-15 nm, but the thickness is not limited to this range.

[0119] Hole transport layer

[0120] In the organic electroluminescent device of the present invention, a hole transport layer may be disposed above the hole injection layer. The hole transport material is a suitable material having a high hole mobility, which can accept holes from the anode or the hole injection layer and transfer the holes to the light-emitting layer. Specific examples thereof include: aromatic amine organic materials, conductive polymers, block copolymers having both conjugated and non-conjugated parts, etc., but are not limited thereto. In a preferred embodiment, the hole transport layer comprises a compound containing a naphtho-pentacyclic oxygen-containing heterocyclic structure of the same general formula (1) as the hole injection layer.

[0121] The thickness of the hole transport layer of the present invention may be 80-200 nm, preferably 100-150 nm, but the thickness is not limited to this range.

[0122] Electron blocking layer

[0123] In the organic electroluminescent device of the present invention, the electron blocking layer may be disposed between the hole transport layer and the light emitting layer, and in particular in contact with the light emitting layer. The electron blocking layer is disposed to contact the light emitting layer, and therefore, hole transfer at the interface between the light emitting layer and the hole transport layer can be precisely controlled. In one embodiment of the present invention, the electron blocking layer material is selected from carbazole aromatic amine derivatives. The thickness of the electron blocking layer may be 5-20 nm, preferably 8-15 nm, but the thickness is not limited to this range.

[0124] The present invention does not deny the principle of substrate matching of traditional hole-type materials, but further superimposes on the physical property parameters of traditional material screening, that is, it recognizes the influence of HOMO energy level, carrier mobility, film phase stability, thermal stability of materials, etc. on the hole injection efficiency of organic electroluminescent devices. On this basis, the material screening conditions are further increased, and then by selecting more excellent organic electroluminescent materials for device matching, the accuracy of material selection for preparing high-performance organic electroluminescent devices is improved.

[0125] Electron transport region

[0126] In the organic electroluminescent device of the present invention, the electron transport region is disposed between the light emitting region and the cathode, and includes an electron transport layer and an electron injection layer, but is not limited thereto.

[0127] Electron injection layer

[0128] The electron injection layer may be disposed between the electron transport layer and the cathode. The electron injection layer material is generally preferably a material having a low work function so that electrons are 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 of the organic electroluminescent device of the present invention, the electron injection layer material for organic electroluminescent devices known in the prior art can be used, for example, lithium; lithium salts, such as 8-hydroxyquinoline lithium, lithium fluoride, lithium carbonate or lithium azide; or cesium salts, cesium fluoride, cesium carbonate or cesium azide. The thickness of the electron injection layer of the present invention can be 0.1-5nm, preferably 0.5-3nm and more preferably 0.8-1.5nm, but the thickness is not limited to this range.

[0129] Electron transport layer

[0130] The electron transport layer may be disposed on the light-emitting film layer or (if present) the hole blocking layer. The electron transport layer material is a material that easily receives 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 electron transport layer materials for organic electroluminescent devices known in the prior art can be used, for example, metal complexes of hydroxyquinoline derivatives represented by Alq3, BAlq and LiQ, various rare earth metal complexes, triazole derivatives, 2,4-bis(9,9-dimethyl-9H-fluorene-2-yl)-6-(naphthalene-2-yl)-1,3,5-triazine (CAS No.: 1459162-51-6) and other triazine derivatives, 2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole (CAS No.: 561064-11-7, commonly known as LG201) and other imidazole derivatives, oxadiazole derivatives, etc.

[0131] In a preferred organic electroluminescent device of the present invention, the electron transport region comprises a nitrogen heterocyclic compound represented by the following general formula (10):

[0132]

[0133] In the general formula (10), Ar1, Ar2, and Ar3 are independently substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C5-C 30 One of the heterocyclic groups;

[0134] L1 is selected from a single bond, a substituted or unsubstituted C6-C 30 Arylene, substituted or unsubstituted C5-C 30 A heterocyclylene group;

[0135] The heteroatoms are each independently selected from N, O or S;

[0136] X1, X2, and X3 independently represent N or CH, and at least one of X1, X2, and X3 represents N.

[0137] In a preferred embodiment of the present invention, the electron transport layer comprises any one of the following compounds:

[0138]

[0139]

[0140] In a more preferred embodiment of the present invention, the electron transport layer comprises any one of the compounds selected from the following:

[0141]

[0142] In a preferred embodiment of the present invention, in addition to the compound of general formula (9), the electron transport layer also includes other compounds conventionally used in electron transport layers, for example, Alq3, LiQ, preferably LiQ. In a more preferred embodiment of the present invention, the electron transport layer is composed of one of the compounds of general formula (19) and one of the other compounds conventionally used in electron transport layers (preferably LiQ).

[0143] The hole injection and transport rates of the hole transport region containing the compound of the present invention can be well matched with the electron injection and transport rates. Preferably, the hole injection and transport rates of the hole transport region containing the compound of the present invention can be better matched with the electron injection and transport rates of the electron transport region containing the nitrogen heterocyclic derivative of general formula (9).

[0144] Therefore, in a particular embodiment of the present invention, an electron transport region comprising one or more nitrogen heterocyclic derivatives of the general formula (9) or consisting thereof is used in combination with a hole transport region comprising the compound of the present invention to achieve relatively better technical effects.

[0145] 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, but the thickness is not limited to this range.

[0146] Covering

[0147] In order to improve the light extraction efficiency of the organic electroluminescent device, a light extraction layer (i.e., CPL layer, also called covering layer) may be added to the cathode of the device. According to the principles of optical absorption and refraction, the refractive index of the CPL covering layer material should be as high as possible, and the absorption coefficient should be as small as possible. Any material known in the art can be used as the CPL layer material, such as Alq3, or N4,N4'-diphenyl-N4,N4'-di(9-phenyl-3-carbazolyl)biphenyl-4,4'-diamine. The thickness of the CPL covering layer is generally 5-300 nm, preferably 20-100 nm and more preferably 40-80 nm.

[0148] The organic electroluminescent device of the present invention may further include an encapsulation structure. The 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 can or a metal can; or a thin film covering the entire surface of the organic layer.

[0149] Hereinafter, an organic electroluminescent device according to an embodiment of the present invention is described.

[0150] In the accompanying drawings, the thickness of layers, films, substrates, regions, etc., is exaggerated for clarity. Throughout the specification, the same reference numerals represent the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "located" "on" another element, it can be directly located on the other element or there can also be intervening elements. In contrast, when an element is referred to as being "directly located" "on" another element, there are no intervening elements.

[0151] Figure 1 is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present invention.

[0152] See also Figure 1 , 1 is a transparent substrate layer, 2 is an anode layer, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is a light emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, 10 is a cathode layer, and 11 is a CPL layer.

[0153] A method for preparing an organic electroluminescent device, comprising laminating an anode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic film layer, an electron transport layer, an electron injection layer and a cathode successively on a substrate, and optionally a covering layer. In this regard, vacuum deposition, vacuum evaporation, spin coating, casting, LB method, inkjet printing, laser printing or LITI methods can be used, but are not limited thereto. In the present invention, preferably vacuum evaporation is used to form the various layers. Those skilled in the art can conventionally select various process conditions in the vacuum evaporation method according to actual needs.

[0154] 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 of layers formed into films alone and layers formed into films after mixing.

[0155] Exemplary embodiments have been disclosed herein, and although specific terms are used therein, these terms are used and interpreted only as general and descriptive meanings, and not for limiting purposes. In some cases, as will be apparent to those of ordinary skill in the art with the filing of this application, unless specifically indicated, the features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with the features, characteristics, and / or elements described in conjunction with other embodiments. Accordingly, it will be understood by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the invention.

[0156] The following examples are intended to better explain the present invention, but the scope of the present invention is not limited thereto.

[0157] Example

[0158] Unless otherwise specified, various materials used in the following examples and comparative examples are commercially available or can be obtained by methods known to those skilled in the art.

[0159] Synthesis of Intermediate A

[0160] Synthesis of intermediate A-1:

[0161]

[0162] Under nitrogen protection, add 6-bromonaphthalene-2-ol (11.15 g, 50 mmol) and DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 13.62 g, 60 mmol) in a 500 ml round-bottom flask. After nitrogen is passed for 30 min to replace the air three times, add phenylacetylene (20.43 g, 200 mmol), BF3·Et2O (0.35 g, 2.5 mmol), toluene (240 mL), and CHCl3 (60 mL). Heat to 80°C for 5 h under nitrogen protection. The reaction solution was taken for TCL detection and it was found that 6-bromonaphthalene-2-ol had reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, water (60 mL) was added to quench the reaction, the solvent was removed by rotary evaporation, and the residue was dissolved in ethyl acetate (150 mL), washed with 100 ml of water, poured into a separatory funnel and shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with ethyl acetate (50 ml * 3), the organic phases were combined and dried with anhydrous magnesium sulfate, filtered, and the filtrate was subjected to rotary evaporation to remove ethyl acetate to obtain a crude product, which was purified by silica gel chromatography to obtain intermediate A-1. Elemental analysis structure (molecular formula C 18 H 11 BrO): Analytical values: C, 66.88; H, 3.40; Br, 24.77. LC-MS ([M+H] + ): The measured value is 323.10.

[0163] Synthesis of intermediate A-2:

[0164]

[0165] Under nitrogen protection, in a 500ml round-bottom flask, 6-bromonaphthalene-2-ol (11.15g, 50mmol), bromoacetaldehyde diethyl acetal (12.32g, 62.5mmol), K2CO3 (8.85g, 64mmol), DMF (100mL) were added in sequence, and nitrogen was passed through for 30min to replace the air three times, and then heated to 110°C under nitrogen protection for 20h. The reaction solution was taken for TCL detection and it was found that 6-bromonaphthalene-2-ol reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, and the solvent was removed by rotary evaporation. The residue was added with ethyl acetate (150mL) to dissolve, and 100ml of water was added for washing. After pouring into a separatory funnel and shaking, it was allowed to stand for stratification. After separation, the aqueous phase was extracted with ethyl acetate (50ml*3), and the organic phases were combined and dried with anhydrous magnesium sulfate, filtered, and the filtrate was evaporated to remove ethyl acetate to obtain a crude product, which was purified by silica gel chromatography to obtain intermediate B. Elemental analysis structure (molecular formula C 16 H 19 BrO3): Analytical values: C, 56.61; H, 5.66; Br, 23.58. LC-MS ([M+H] +): The measured value is 339.28.

[0166] Under nitrogen protection, polyphosphoric acid (25.60 g) and toluene (100 mL) were added to a 500 ml round-bottom flask in sequence, stirred evenly, and nitrogen was passed through for 30 minutes to replace the air three times. Then, a mixture of intermediate B (8.48 g, 25 mmol) dissolved in toluene (100 mL) was added dropwise, and the mixture was heated under reflux for 1 hour under nitrogen protection. The reaction solution was taken for TCL detection and it was found that the intermediate B reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, 1 mol / L NaOH solution (150 mL) was added to the reaction system, poured into a separatory funnel, shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with ethyl acetate (50 ml * 3), the organic phases were combined, dried with anhydrous magnesium sulfate, filtered, and the filtrate was removed by rotary evaporation to obtain a crude product. The crude product was purified by silica gel chromatography to obtain intermediate A-2. Elemental analysis structure (molecular formula C 12 H7BrO): Analytical values: C, 58.34; H, 2.89; Br, 32.32; LC-MS ([M+H] + ): The measured value is 246.91.

[0167] Example 1: Synthesis of Compound 1:

[0168] Step (1)

[0169] Step (2)

[0170] In a 250 ml three-necked flask, under a nitrogen atmosphere, add 0.012 mol of raw material E, 0.01 mol of raw material F, 0.03 mol of potassium tert-butoxide, and 1×10 -4 mol tris(dibenzylideneacetone)dipalladium Pd2(dba)3, 1×10 -4 mol triphenylphosphine, 150ml toluene, heated to reflux for 12 hours, sampled and plated, indicating that the reaction was complete. Naturally cooled, filtered, the filtrate was rotary evaporated, and passed through a silica gel column (silica gel 100-200 mesh, eluent: chloroform: n-hexane = 1:2 (volume ratio)) to obtain intermediate M. Elemental analysis structure (molecular formula C 27 H 23 N): Analytical found values: C, 89.76; H, 6.40; N, 3.84. LC-MS ([M+H] + ): The measured value is 362.13.

[0171] In a 250 ml three-necked flask, under a nitrogen atmosphere, 0.012 mol of intermediate A-1, 0.01 mol of intermediate M, 0.03 mol of potassium tert-butoxide, and 1×10 -4mol tris(dibenzylideneacetone)dipalladium Pd2(dba)3, 1×10 -4 mol triphenylphosphine, 150ml toluene, heated to reflux for 12 hours, sampled and plated, indicating that the reaction was complete. Naturally cooled, filtered, the filtrate was rotary evaporated, and passed through a silica gel column (silica gel 100-200 mesh, eluent: chloroform: n-hexane = 1:2 (volume ratio)) to obtain compound 1. Elemental analysis structure (molecular formula C 45 H 33 NO): Analytical values: C, 89.57; H, 5.48; N, 2.31. LC-MS ([M+H] + ): The measured value is 604.19.

[0172] The following numbered compounds were prepared by the same method as in Example 1. The synthetic raw materials are shown in Table 1. The synthetic method of the compounds of the present invention can refer to the prior art CN110577511A.

[0173] In order to carry out structural analysis of the compounds prepared in the examples, LC-MS measurements were performed as shown in Table 1.

[0174] Table 1

[0175]

[0176]

[0177]

[0178] Detection Methods

[0179] Glass transition temperature Tg: measured by differential scanning calorimetry (DSC, DSC204F1 differential scanning calorimeter from NETZSCH, Germany), with a heating rate of 10°C / min.

[0180] HOMO energy level: tested by ionization energy test system (IPS3) in a vacuum environment.

[0181] Eg energy level: tested by double-beam UV-visible spectrophotometer (model: TU-1901), based on the UV spectrophotometry (UV absorption) baseline of the material single film and the rising side of the first absorption peak, the tangent is drawn and the value of the intersection of the tangent and the baseline is calculated.

[0182] Hole mobility: The material of the present invention is made into a single charge device and measured by the SCLC method.

[0183] Triplet energy level T1: tested by Horiba's Fluorolog-3 series fluorescence spectrometer, the material test conditions are 2*10 -5 mol / L toluene solution.

[0184] The specific physical property test results are shown in Table 2.

[0185] Table 2

[0186]

[0187]

[0188] It can be seen from the data in Table 2 above that the compounds of the present invention have suitable HOMO energy levels, higher hole mobility and wider band gap (Eg), which can help to realize organic electroluminescent devices with high efficiency, low voltage and long life.

[0189] Preparation of organic electroluminescent devices

[0190] The molecular structures of the materials involved in the following preparation process are shown below:

[0191]

[0192] Device Comparative Example 1

[0193] The organic electroluminescent device was prepared by following the steps below:

[0194] a) using transparent glass as a substrate, washing the anode layer 2 (Ag (100 nm)) thereon, i.e., sequentially performing alkali washing, pure water washing, drying, and then performing ultraviolet-ozone washing to remove organic residues on the surface of the anode layer;

[0195] b) on the washed anode layer 2, using a vacuum evaporation device, 10 nm thick HT1 and P-type doped HI1 were evaporated as the hole injection layer 3, and the mass ratio of HT1 to HI1 was 97:3;

[0196] c) On the hole injection layer, a hole transport layer 4 is deposited by vacuum evaporation. The hole transport layer material is compound HT1 and has a thickness of 117 nm;

[0197] d) On the hole transport layer, an electron blocking layer 5 is deposited by vacuum evaporation, wherein the electron blocking layer material is EB-1 and has a thickness of 10 nm;

[0198] e) On the electron blocking layer, a light-emitting layer 6 of an OLED light-emitting device is manufactured, wherein the structure includes BH-1 used as a main material of the OLED light-emitting layer 6, BD-1 as a doping material, the doping ratio of the doping material is 3% by weight, and the thickness of the light-emitting layer is 20 nm;

[0199] f) On the light-emitting layer, HB1 is continuously evaporated as a hole blocking layer 7, and the evaporated film thickness is 8 nm;

[0200] g) On the hole blocking layer, ET1 and LiQ are evaporated by vacuum evaporation, the mass ratio of ET1 and LiQ is 50:50, and the thickness is 30 nm. This layer serves as the electron transport layer 8;

[0201] h) LiF is deposited on the electron transport layer by vacuum evaporation with a thickness of 1 nm, and this layer is the electron injection layer 9;

[0202] i) on the electron injection layer, a Mg:Ag (1:9) electrode layer is vacuum-deposited with a thickness of 16 nm, which is the cathode layer 10;

[0203] j) On the cathode layer, 70 nm of CP-1 was vacuum-deposited as the CPL layer 11.

[0204] Device Comparative Examples 2-3 were carried out according to the method of Device Comparative Example 1, except that the organic materials in step b) / c) were replaced by organic materials shown in Table 3. Device Comparative Examples 4-6 were carried out according to the method of Device Comparative Example 1, except that the organic materials in b) / c) / g) were replaced by organic materials shown in Table 3. Device Preparation Examples 1-18 were carried out according to the method of Device Comparative Example 1, except that the organic materials in step b) / c) were replaced by organic materials shown in Table 3. Device Preparation Examples 19-24 were carried out according to the method of Device Comparative Example 1, except that the organic materials in b) / c) / g) were replaced by organic materials shown in Table 3.

[0205] Table 3

[0206]

[0207]

[0208] In the above table, taking Example 1 as an example, "3:HI1(3%10nm)" in the second column means that the materials used for the hole injection layer are compound (3) and P-type dopant material HI1, and 3% refers to the weight ratio of P-type dopant material HI1 to the materials used for the hole injection layer: 10nm means the thickness of the layer; "3(117nm)" in the third column means that the material used is compound (3) and the thickness of the layer is 117nm. The meanings in other tables can be deduced by analogy.

[0209] After the OLED light emitting device is prepared as described above, the cathode and the anode are connected by a known driving circuit, and various properties of the device are measured. The measured performance results of the devices of Examples 1-24 and Comparative Examples 1-6 are shown in Table 4.

[0210] Table 4

[0211]

[0212]

[0213] Note: Voltage, current efficiency and color coordinates were tested using an IVL (current-voltage-luminance) test system (Suzhou Foster Scientific Instrument Co., Ltd.) at a current density of 10 mA / cm 2 The life test system is the EAS-62C OLED device life tester produced by Japan System Engineering Co., Ltd. LT95 refers to the time taken for the device brightness to decay to 95% at a specific brightness. The test temperature for high temperature life is 85°C, and LT80 refers to the time taken for the device brightness to decay to 80% at a specific brightness.

[0214] In Table 4, voltage represents the driving voltage of the device, that is, the device voltage, and voltage @1nits represents the turn-on voltage. It can be seen from the results of Comparative Examples 1-3 and Device Examples 1-18 in Table 4 that the use of the naphthoxypentacyclic oxygen-containing heterocyclic compound of the present invention as hole injection and hole transport layer materials has a higher carrier transfer rate, which effectively reduces the device voltage and improves the device efficiency. It can be seen from the turn-on voltage at @1nits that the compound of the present invention significantly reduces the turn-on voltage of the device and reduces the cross-talk risk.

[0215] It can be seen from the results of Comparative Examples 4-6 and Device Examples 19-24 in Table 4 that the naphtho-pentacyclic oxygen-containing heterocyclic compound of the present invention is used in combination with a specific electron transport layer material, and this combination effectively improves the lifespan.

[0216] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A compound containing a naphtho-five-membered oxygen-containing heterocyclic structure, characterized in that: The compound structure is shown in general formula (1): In the general formula (1), Z1 and Z2 are independently represented by CR; The L, L1, and L2 are independently represented by a single bond, a substituted or unsubstituted phenylene group; Ar1 and Ar2 are independently represented by substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted thienyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted indenyl, the structure represented by general formula (2), general formula (3) or general formula (4), and at least one of Ar1 and Ar2 is represented by the structure represented by general formula (2), general formula (3) or general formula (4), and when Ar1 is represented by the structure represented by general formula (3), the side chains represented by L2 and Ar2 cannot be phenyl; In the general formula (3), Ra and Rb are independently represented by methyl or phenyl; Said R, R1, and R2 are independently represented by a hydrogen atom, a deuterium atom or a phenyl group; The R3 is a hydrogen atom, a deuterium atom or a phenyl group, and when R3 is a phenyl group, a and b, b and c or c and d can form a ring with the general formula (3); The R4 is a hydrogen atom or a phenyl group; The L3 represents a single bond or a phenylene group; The substituent of the "substituted or unsubstituted" group is selected from one or more of a deuterium atom, a tert-butyl group, and a phenyl group.

2. The compound according to claim 1, wherein: The compound structure is shown in general formula (5): In the general formula (5), L represents a phenylene group, and L1 and L2 each independently represent a single bond or a phenylene group; The definitions of Ar1, Ar2, R1 and Z2 are as described in claim 1.

3. The compound containing a naphtho-five-membered oxygen-containing heterocyclic structure according to claim 1, characterized in that: The compound structure is shown in general formula (6-1) or general formula (6-2): In the general formula (6-1) and the general formula (6-2), L is a phenylene group, L1 and L2 are independently represented by a single bond or a phenylene group; the definitions of Ar1 and Ar2 are as described in claim 1.

4. The compound according to claim 1, wherein: The compound structure is shown in general formula (7-1) or general formula (7-2): In the general formula (7-1) and the general formula (7-2), the connection site between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*; The L is a phenylene group, and L1 and L2 are independently represented by a single bond or a phenylene group; the definitions of Ar1, Z1, Z2, Ra, and Rb are as described in claim 1.

5. The compound containing a naphtho-five-membered oxygen-containing heterocyclic structure according to claim 1, characterized in that: The compound structure is shown in general formula (8-1) or general formula (8-2): In the general formula (8-1) and the general formula (8-2), the definitions of L1, L2, Ar1, and Ar2 are as described in claim 1.

6. The compound containing a naphtho-five-membered oxygen-containing heterocyclic structure according to claim 1, characterized in that: The compound structures are shown in general formula (9-1) to general formula (9-3): In general formula (9-1) to general formula (9-3), the connection site between L and the naphtho-five-membered oxygen-containing heterocycle is 1*, 2*, 3* or 4*; The definitions of L, L1, L2, Ar1, Z1, Z2, Ra, and Rb are as described in claim 1.

7. The compound containing a naphtho-five-membered oxygen-containing heterocyclic 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, which comprises an anode, a hole transport region, a light emitting region, an electron transport region and a cathode in sequence, characterized in that: The hole transport region comprises the compound containing a naphtho-five-membered oxygen-containing heterocyclic structure according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, characterized in that: The hole transport region comprises a hole injection layer, a first hole transport layer and an electron blocking layer, wherein the first hole transport layer and the hole injection layer comprise the compound containing a naphtho-five-membered oxygen-containing heterocyclic structure according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9, characterized in that: The first hole transport layer comprises the compound containing a naphthoxy-five-membered oxygen-containing heterocyclic structure according to any one of claims 1 to 7, and the hole injection layer consists of the compound containing a naphthoxy-five-membered oxygen-containing heterocyclic structure according to any one of claims 1 to 7 and other doping materials for the hole injection layer.

11. The organic electroluminescent device according to claim 8, characterized in that: The electron transport region comprises a nitrogen heterocyclic compound represented by the following general formula (10): In the general formula (10), Ar3, Ar4, and Ar5 are independently substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C2-C 30 One of the heterocyclic groups; L0 is selected from a single bond, a substituted or unsubstituted C6-C 30 Arylene, substituted or unsubstituted C2-C 30 A heterocyclylene group; X1, X2, and X3 independently represent N or CH, and at least one of X1, X2, and X3 represents N; The substituents for the substituent groups are selected from deuterium, tritium, C 1-10 Alkyl, C6-C 30 One or more of an aryl group, a C2-C30 heteroaryl group containing one or more heteroatoms; The heteroatom is selected from N, O or S. 12 . A display device comprising the organic electroluminescent device according to claim 8 .

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