A stable organic electroluminescent device

Abstract

The present application relates to a kind of stable organic electroluminescent devices, including first electrode and second electrode, first electrode and second electrode are provided with organic layer between, organic layer at least includes one or more layers of first hole transport layer, first light-emitting layer and first electron transport layer;First light-emitting layer is located between first hole transport layer and first electron transport layer;First light-emitting layer at least includes one or more anthracene derivatives, anthracene derivative includes as shown in formula I compound: first hole transport layer includes triarylamine derivative compound, and triarylamine derivative compound includes as shown in formula II compound.The active site of the light-emitting layer of the present application or the layer in contact with light-emitting layer simultaneously uses the strategy of deuteration or alkylation, can effectively improve the device life under high temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic electroluminescence devices, in particular to a stable organic electroluminescence device. BACKGROUND

[0002] OLED is widely used in mobile phones, televisions, VR and other application scenarios. OLED has the characteristics of solid state, high efficiency, self-luminescence, and bendable, but the service life of OLED is relatively poor, especially the service life of blue light. The service life of blue light is still barely acceptable at room temperature, but in high-temperature environments, such as vehicle-mounted scenes at high temperatures, the service life of blue light is shorter, which limits the wide application of OLED. The conventional strategy is to increase the size of the blue light emitting pixel or improve the luminous efficiency of the blue light emitting pixel to improve the service life. However, the essential reason for the reduction of the service life is still the poor thermal stability of the organic material, and increasing the stability of the organic material is an important method. SUMMARY

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an organic electroluminescence device for solving the problems in the prior art.

[0004] To achieve the above-mentioned purposes and other related purposes, one aspect of the present application provides an organic electroluminescence device, comprising a first electrode and a second electrode, an organic layer is arranged between the first electrode and the second electrode, the organic layer comprises at least one or more first hole transport layers, a first light emitting layer and a first electron transport layer; the first light emitting layer is located between the first hole transport layer and the first electron transport layer; the first light emitting layer is in contact with the first hole transport layer; the first light emitting layer is in contact with the first electron transport layer;

[0005] The first light emitting layer comprises at least one or more anthracene derivatives, and the anthracene derivative comprises a compound as shown in formula I:

[0006]

[0007] Y1-Y2 are each independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heterocyclic group;

[0008] The first hole transport layer comprises a triarylamine derivative-containing compound, and the triarylamine derivative-containing compound comprises a compound as shown in formula II:

[0009]

[0010] Y3-Y5 are each independently selected from the group consisting of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heterocyclic group, deuterium, linear, branched or cyclic alkyl group;

[0011] Ar1-Ar3 are each independently selected from the group consisting of substituted or unsubstituted arylene, substituted or unsubstituted heterocyclic group; and at least one of the three groups Ar1-Ar3 has hydrogen substituted with deuterium or alkyl group.

[0012] In another aspect, the present application provides a display device comprising the organic electroluminescent device as described above.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] The present application can obtain high lifetime to a great extent by precisely identifying the active site of the excited state and precisely deuterating or alkylating the hydrogen of the active site, and the device construction is relatively low in cost. More importantly, after the hydrogen of the multi-layer active site is precisely deuterated or alkylated, the device has very high lifetime at high temperature. This method is more economical than the compounds used in the all-deuterated device, and has better performance than the single-layer compounds in the only-deuterated device. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of device A in an embodiment of the organic electroluminescent device.

[0016] Figure 2 is a structural schematic diagram of device B in an embodiment of the organic electroluminescent device.

[0017] In the figure:

[0018] 1 substrate

[0019] 2 first electrode

[0020] 3 hole injection layer

[0021] 4 second hole transport layer

[0022] 5 first hole transport layer

[0023] 6 first light-emitting layer

[0024] 7 first electron transport layer

[0025] 8 second electron transport layer

[0026] 9 second electrode

[0027] 10 cover layer DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the specifically disclosed organic electroluminescent device and the application thereof in the organic electroluminescent device will be described in detail. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification. The present application can also be implemented or applied by other different embodiments, and the details in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0029] Before further describing the embodiments of the present application, it should be understood that the scope of protection of the present application is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present application are used to describe the specific embodiments, not to limit the scope of protection of the present application; in the specification and claims of the present application, the singular forms "a", "an" and "the" include the plural forms unless otherwise explicitly stated in the text.

[0030] When the embodiments give numerical ranges, it should be understood that, unless otherwise stated by the present application, both endpoints of each numerical range and any number between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art. In addition to the specific methods, devices, materials used in the embodiments, any method, device and material of the prior art similar or equivalent to those described in the embodiments of the present application can also be used to implement the present application according to the mastery of the prior art by those skilled in the art and the description of the present application.

[0031] The present inventors have made a lot of exploratory research and provided an organic electroluminescent device, which is a high-stability blue OLED device. By analyzing the lifetime reduction mechanism of the OLED device, the present application proposes a strategy of simultaneously using deuterium or alkylation for the active sites of the lifetime-sensitive layer (light-emitting layer or layer in contact with the light-emitting layer), which can effectively improve the device lifetime under high temperature. On this basis, the present application is completed.

[0032] Examples of substituents in the present application are described as follows, but the substituents are not limited thereto:

[0033]

Substituted or Unsubstituted

[0034]

Aryl

[0035] The above description of aryl group can be applied to arylene group, with the difference that arylene group is divalent.

[0036] The above description of aryl group can be applied to aryl group in aryloxy group, arylthio group, arylsulfonyl group, arylphosphine group, aralkyl group, aralkylamine group, aralkenyl group, alkylaryl group, arylamine group, and arylheteroarylamine group.

[0037] [Het] contains one or more of N, O, P, S, Si, and Se as a heteroatom. Het includes, but is not limited to, pyridyl, pyrrolyl, pyrimidinyl, pyridazinyl, furanyl, thienyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, dithiazolyl, tetrazolyl, pyranyl, thiopyranyl, pyrazinyl, oxazinyl, thiazinyl, dioxinyl, triazinyl, tetrazinyl, quinolinyl, isoquinolinyl, quinolinyl, quinazolinyl, quinoxalinyl, naphthrydinyl, acridinyl, xanthenyl, phenanthridinyl, phthalazinyl, indolizinyl, indolyl, indolinyl, indolizinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, benzothienyl, benzofuranyl, dibenzothienyl, dibenzofuranyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indolophenanthrolinyl, phenoxazinyl, imidazopyridinyl, phenothiazinyl, imidazophenanthridinyl, benzimidazoquinazolinyl, benzimidazophenanthrolinyl, spiro[fluorene-9,9'-xanthene], phenalenyl, naphthofuranyl, naphthothienyl, triphenylphosphine oxide, triphenylborane, and the like.

[0038] The above description of Het can be used for heteroaryl, with the difference that heteroaryl is aromatic.

[0039] The above description of Het can be used for heteroaryl, heteroarylamino, and arylheteroarylamino.

[0040] The above description of Het can be used for heteroarylene, with the difference that heteroarylene is divalent.

[0041] [Alkyl] can be straight-chained or branched or cyclic, and the number of carbon atoms is not particularly limited. In some embodiments, alkyl includes, but is not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, t-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, t-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, iso-hexyl, 4-methylhexyl, 5-methylhexyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and the like.

[0042] The above description of alkyl groups is applicable to the alkyl groups in alkylthio, alkylsulfonyl, aralkyl, aralkylamino, alkylaryl, and alkylamino groups.

[0043] In one aspect, the present application provides an organic electroluminescent device, comprising a first electrode and a second electrode, wherein the first electrode is an anode and the second electrode is a cathode, and the cathode can be one layer or multiple layers. An organic layer is arranged between the first electrode and the second electrode, and the organic layer can be a single layer structure or a multi-layer series structure with two or more organic layers laminated. The organic layer comprises at least one or more first hole transport layers, a light-emitting layer, and a first electron transport layer; the light-emitting layer is located between the first hole transport layer and the first electron transport layer. The first light-emitting layer is in contact with the first hole transport layer; the first light-emitting layer is in contact with the first electron transport layer.

[0044] In some embodiments, a hole injection layer is arranged between the first electrode and the first hole transport layer; the first electrode is an anode.

[0045] In some embodiments, a second hole transport layer is arranged between the hole injection layer and the first hole transport layer.

[0046] In some embodiments, a second light-emitting layer is further included, and the first hole transport layer is two layers, and a second light-emitting layer and a charge generation layer are further arranged in sequence between the two layers of the first hole transport layer.

[0047] In some embodiments, an electron injection layer is further included, and the electron injection layer is arranged between the first electron transport layer and the second electrode.

[0048] In some embodiments, a second electron transport layer is further included, and the second electron transport layer is arranged between the first electron transport layer and the second electrode; preferably, a third electron transport layer is further included, and the third electron transport layer is arranged between the second electron transport layer and the second electrode.

[0049] In some embodiments, the light-emitting direction is from the cathode side, and a cover layer is arranged on the side of the cathode side away from the first electron transport layer.

[0050] In some specific embodiments, the organic electroluminescent device structure can be selected from one of the following:

[0051] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode.

[0052] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode.

[0053] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, an electron injection layer, and a cathode.

[0054] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, an electron injection layer, and a cathode.

[0055] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, a multi-layer cathode.

[0056] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, and a cathode.

[0057] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a second electron transport layer, and a cathode.

[0058] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, and a cathode.

[0059] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a second electron transport layer, and a cathode.

[0060] Wherein, the light-emitting direction is from the cathode side, and a covering layer is additionally provided on the cathode side. The structure is as follows:

[0061] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a cathode, and a covering layer.

[0062] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a cathode, and a covering layer.

[0063] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, a cathode, and a covering layer.

[0064] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, an electron injection layer, a cathode, and a cover layer.

[0065] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, a multi-layer cathode, and a cover layer.

[0066] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a cathode, and a cover layer.

[0067] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a first hole transport layer, a second light-emitting layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a second electron transport layer, a cathode, and a cover layer.

[0068] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a second light-emitting layer, a second electron transport layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a cathode, and a cover layer.

[0069] The organic electroluminescent device comprises, in sequence, an anode, a hole injection layer, a second hole transport layer, a first hole transport layer, a second light-emitting layer, a third electron transport layer, a charge generation layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a second electron transport layer, a cathode, and a cover layer.

[0070] The organic electroluminescent device provided by the application uses the following materials:

[0071] anode :

[0072] The anode of the organic EL element is required to have good conductivity, a flat surface, and not be prone to cracking, among other requirements. The work function is also required to be a certain value, and is mainly required to match the hole injection layer to achieve hole injection, and is generally required to be 4.5 eV or more. In some embodiments, the anode material can be selected from, for example, a combination of one or more of indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, and the like. The anode can be formed by forming a thin film of the aforementioned electrode material using a method such as evaporation, sputtering, coating, or the like. In some specific embodiments, the anode is generally used at a thickness of 10 nm to 1 μm, and the thickness of the anode can also be 10 nm to 20 μm, 20 nm to 100 nm, 100 nm to 300 nm, 300 nm to 500 nm, 500 nm to 800 nm, or 800 nm to 1000 nm, or the like. Use in the range of 20 nm to 100 nm is preferred.

[0073] hole injection layer :

[0074] The thickness of the hole injection layer can be, for example, 3 nm to 20 nm, 3 nm to 10 nm, 10 nm to 15 nm, or 15 nm to 20 nm, or the like. The hole injection layer uses a P-type material mixed with a hole transport material, and the purpose of the P-type material is to accept holes from the anode and transfer them to the hole transport material. The weight ratio of the P-type material in the hole injection layer can be, for example, 0.5% to 10%, 0.5% to 3%, 3% to 5%, or 5% to 10%, or the like. When the weight ratio is 0.5% to 3%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) level of the P-type material and the highest occupied molecular orbital (HOMO) level of the HTL material must be 0.2 eV or less, when the weight ratio is 3% to 5%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) level of the P-type material and the highest occupied molecular orbital (HOMO) level of the HTL material must be 0.3 eV or less, and when the weight ratio is 5% to 10%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) level of the P-type material and the highest occupied molecular orbital (HOMO) level of the HTL material must be 0.5 eV or less.

[0075] The P-type material can be a metal oxide, such as molybdenum oxide, vanadium oxide, tungsten oxide, etc.; or an organic material, such as 4,4',4"-((1E,1'E,1"E)-cyclopropane-1,2,3-trimethylene tri(carbonylformyl)) tri(2,3,5,6-tetrafluorobenzyl) (PD1, CAS No. 1224447-88-4), tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), etc., and is not limited thereto. The hole transport material of the P-type material can be selected from the second hole transport layer, such as being selected from the same material as the second hole transport layer, and in some embodiments, can be different.

[0076] second hole transport layer

[0077] The second hole transport layer is generally 40 nm to 150 nm thick, and typically contains an aryl amine compound, such as an aromatic monoamine, or an aromatic polyamine. In some embodiments, the second hole transport layer can or can not be present, and when present, is typically located between the hole injection layer and the first hole transport layer. Some examples of the second hole transport layer are listed below:

[0078]

[0079] first hole transport layer

[0080] ​The first hole transport layer can have a thickness of 3 nm to 150 nm, 3 nm to 40 nm, 40 nm to 150 nm, etc. When there is no second hole transport layer, the first hole transport layer can have a thickness of 40 nm to 150 nm, 40 nm to 80 nm, 80 nm to 120 nm, or 120 nm to 150 nm, etc. When there is a second hole transport layer, the first hole transport layer can have a thickness of 3 nm to 40 nm, 3 nm to 10 nm, 10 nm to 20 nm, 20 nm to 30 nm, or 30 nm to 40 nm, etc. The first hole transport layer is the hole transport layer in contact with the light-emitting layer. The first hole transport layer uses a deuterated compound, such as a compound of the present application that contains a triarylamine derivative. The speed of the hole transport process of a hole transport material is determined by the charge transfer integral of the molecule and the reorganization energy, and the highest occupied molecular orbital (HOMO) has a large contribution to the charge transfer integral. The nitrogen of the triarylamine has a lone pair of electrons, so the HOMO orbital is often distributed on the triarylamine, so the structure centered on the nitrogen is the main contribution to the charge transport and the part with the strongest electron effect. In the hole transport process or the process of the interaction of the exciton of the light-emitting layer with the polaron of the hole transport material, the vibration of the molecular bond is involved. If the molecular bond vibration of the hole transport material is severe, the molecular bond is easily broken due to molecular vibration. Because of the electron effect on the triarylamine, the vibration of the C-H bond around the nitrogen is more severe, so it is easy to break or generate a free radical due to the exciton of the light-emitting layer, thereby destroying the molecular structure. To solve this problem, the C-N bond around the connecting nitrogen of the hole transport material can be substituted with an alkyl group or deuterated. After such substitution or deuteration, the C-H bond becomes a C-D bond or a C-C bond, and the molecule becomes more stable. When in a high-temperature environment, the vibration of the C-N bond becomes more severe than at low temperature, and the probability of forming a free radical state or bond rupture is greater. Therefore, in a high-temperature environment, the beneficial effect of such substitution is very obvious.

[0081] In OLED blue light devices, the principle of singlet generation by triplet-triplet annihilation is often used to improve the light-emitting efficiency. Specifically, the light-emitting center is adjusted to the interface between the first hole transport layer and the light-emitting layer. Due to the collision of high-concentration triplet excitons, exciton annihilation occurs, and new singlet excitons are generated. The consequence of this approach is that the destruction of excitons to the first hole transport layer is increased, especially making the hole transport layer material more likely to cause the hydrogen in C-H to leave the system due to bond vibration, forming an unstable free radical state. Therefore, it is more important to protect the aromatic C-H around the nitrogen from weakening vibration.

[0082] When using such a device structure, the protection of the C-H bond of the hole transport layer is more important than the protection of the C-H bond of the electron transport layer.

[0083] Of course, it is more beneficial to protect all C-H bonds in the molecular structure without considering the cost of use. However, due to the actual production and use, the cost requirement is also high. Deuterium is very rare relative to hydrogen, and the cost of producing compounds is high, so fully deuterated compounds cannot be truly produced and used. Therefore, the precise deuterium method of the present application is of great significance for mass production.

[0084] On the other hand, the inventors also found in the experimental process that the C-H bond becomes C-C bond also has a protective effect. However, the introduction of C-C bond will have a greater impact on the performance of the molecule than deuterium substitution. For example, using benzene ring or other aromatic ring can effectively protect the active site, but the electronic effect causes the energy level of the molecule to change, and using alkyl has much less impact on the energy level and can also be used to replace part of the active site. At the same time, alkyl is abundant in resources, and the cost of deuterium substitution will be much lower, so it can also be used as a partial replacement for deuterium. Various compounds containing aromatic amines have this beneficial effect after being substituted with deuterium or alkyl.

[0085] In some embodiments, the first hole transport layer, which is in contact with the light-emitting layer, comprises a triarylamine derivative-containing compound, and the triarylamine derivative-containing compound comprises a compound as shown in Formula II:

[0086]

[0087] wherein Y3-Y5 are each independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heterocyclic group, deuterium, linear, branched, or cyclic alkyl; and Ar1-Ar3 are each independently selected from substituted or unsubstituted arylene, substituted or unsubstituted heterocyclic group; and at least one hydrogen in the three groups of Ar1-Ar3 is substituted with deuterium or alkyl.

[0088] In some embodiments, Y3-Y5 are each independently selected from substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C6-C20 heterocyclic group, deuterium, linear, branched, or cyclic C1-C10 alkyl. In some specific embodiments, the number of carbon atoms in the aryl or heterocyclic group can also be 6-10, 10-20, 20-30, etc.

[0089] Preferably, Y3-Y5are each independently selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted phenanthrenonaphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dinaphthothiophenyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted carbazolyl, deuterium, methyl, ethyl, propyl, n-propyl, i-propyl, butyl, n-butyl, i-butyl, t-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, t-octyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, i-hexyl, 4-methylhexyl, 5-methylhexyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and the like. Further, the substituted or unsubstituted fluorenyl can be substituted or unsubstituted 9,9'-dimethylfluorenyl, substituted or unsubstituted 9,9'-dibenzofluorenyl, substituted or unsubstituted 9,9'-spirobifluorenyl, substituted or unsubstituted spiro[fluorene-9,9'-xanthene], and the like.

[0090] Further preferably, Y3-Y5are each independently selected from the group consisting of phenyl, biphenyl, naphthyl, phenanthryl, anthryl, phenanthrenonaphthyl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl, deuterium, methyl, cyclohexane, and the like.

[0091] In some embodiments, Ar1-Ar3are each independently selected from the group consisting of substituted or unsubstituted C5-C16 arylene, substituted or unsubstituted C5-C16 heteroarylene, and at least one of the hydrogen atoms on the three groups Ar1-Ar3is replaced by deuterium or an alkyl group.

[0092] Preferably, Ar1-Ar3are each independently selected from the group consisting of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, or substituted or unsubstituted biphenylene, and at least some of the hydrogen atoms in Ar1-Ar3are replaced by deuterium or an alkyl group.

[0093] Further preferably, Ar1 to Ar3 are each independently selected from phenylene, naphthylene or biphenylene, and at least one of the three groups Ar1 to Ar3 is substituted with deuterium or an alkyl group instead of hydrogen. Here, the groups refer to Ar1, Ar2 and Ar3.

[0094] The compounds of Formula II can be represented by any of the following chemical structures of Formula BP1 to Formula BP30 as examples:

[0095]

[0096] first light emitting layer, second light emitting layer

[0097] The thickness of the first light-emitting layer or the second light-emitting layer can be generally 15 nm to 30 nm, 15 nm to 20 nm, 20 nm to 25 nm, or 25 nm to 30 nm, etc. The first light-emitting layer or the second light-emitting layer is synthesized by mixing a deuterated compound, such as any of the anthracene-containing derivatives of the present application, as a light-emitting host with a light-emitting guest, or by mixing any two anthracene-containing derivatives as light-emitting hosts with a light-emitting guest. The weight content of the light-emitting guest can be 0.5% to 5%, 0.5% to 1%, 1% to 2%, 2% to 3%, 3% to 4%, or 4% to 5%, etc. The light-emitting host is a medium for the transfer of exciton energy, and its stability is extremely high because the process of transferring excitons forms various excited states, and the molecules are prone to change in the excited states, especially the vibration of the C-H bond in the excited state is more intense. The HOMO and LUMO of the anthracene-containing derivative, especially the 9,10-substituted anthracene derivative, are located on the anthracene, so the C-H bond vibration on the anthracene is more intense and is more prone to breakage. Changing the C-H bond on the anthracene to a C-D bond greatly reduces the vibration and greatly enhances the stability of the molecule. It has been found through experiments that the effect of deuterium substitution at other positions is far less than that of deuterium substitution at the anthracene position.

[0098] In some embodiments, the first light-emitting layer and / or the second light-emitting layer comprises at least one or more anthracene-containing derivatives, which comprise a compound as shown in Formula I:

[0099]

[0100] wherein Y1-Y2 are each independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C6-C30 heterocyclic group.

[0101] In some embodiments, Y1-Y2 are each independently selected from substituted or unsubstituted C6-C20 aryl or substituted or unsubstituted C6-C20 heterocyclic group. In some specific embodiments, the number of carbon atoms in the aryl or heterocyclic group can also be 6-10, 10-20, 20-30, etc.

[0102] Preferably, Y1-Y2 are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted phenanthrenonaphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dinaphthothiophenyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted carbazolyl. Further, the substituted or unsubstituted fluorenyl can be substituted or unsubstituted 9,9'-dimethylfluorenyl, substituted or unsubstituted 9,9'-dibenzofluorenyl, substituted or unsubstituted 9,9'-spirobifluorenyl, substituted or unsubstituted spiro[fluorene-9,9'-xanthene], etc.

[0103] More preferably, Y1-Y2 are each independently selected from phenyl, biphenyl, naphthyl, phenanthryl, anthryl, phenanthrenonaphthyl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl, etc.

[0104] The present application lists some examples, the compounds shown in the formula I can be represented by any of the following chemical structures of formula BH1-BH12:

[0105]

[0106] The doping material can be selected from any of the following compounds:

[0107]

[0108] In an embodiment, the first light-emitting layer and / or the second light-emitting layer each comprises an anthracene derivative and a doping material, and the weight percentage of the anthracene derivative in the light-emitting layer can be 95%-99%, 95%-97%, or 97%-99%, etc. The anthracene derivative can be selected from the compounds of formula I, and more specifically can be selected from any of the compounds of BD1-BD18.

[0109] In another embodiment, the first light-emitting layer and / or the second light-emitting layer each comprises two different anthracene derivatives and a doping material, and the total weight percentage of the two anthracene derivatives in the light-emitting layer can be 95%-99%, 95%-97%, or 97%-99%, etc. The anthracene derivative can be selected from two different structures of the compounds of formula I, and more specifically can be selected from any of the compounds of BD1-BD18.

[0110] first electron transport layer

[0111] The first electron transport layer can have a thickness of 3-40 nm, 3-10 nm, 10-20 nm, 20-30 nm, 30-40 nm, or 20-40 nm. When there is no second electron transport layer, the first electron transport layer can have a thickness of 20-40 nm, and when there is a second electron transport layer, the first electron transport layer can have a thickness of 30-20 nm. The first electron transport layer is in direct contact with the light-emitting layer, and thus, similar to the first hole transport layer, can also undergo electron changes during electron transport, causing increased molecular vibration and molecular deformation. The first electron transport layer can also be affected by the interaction between the excitons of the light-emitting layer and the polarons of the electron transport material, which can easily produce active radicals and damage the electron transport material. The electron transport material can be a single compound or a mixture of other metal compounds, such as Liq.

[0112] In some embodiments, the first electron transport layer is selected from nitrogen-containing heterocyclic compounds, and the hydrogen on the ring is replaced by deuterium or an alkyl group. Preferably, the first electron transport layer is selected from a combination of one or more of pyridine compounds, piperidine compounds, and s-triazine compounds.

[0113] Nitrogen-containing heterocyclic compounds, such as pyridine, piperidine, and s-triazine, have strong electron-withdrawing ability and are very strong electron transport groups. Electron transport mainly depends on the appropriate LUMO position, and pyridine, piperidine, and s-triazine heterocycles have strong electron-withdrawing effects, so they have the greatest contribution to LUMO and are the strongest electron-affected parts. Therefore, the C-H bond vibration of the pyridine, piperidine, and s-triazine ring is relatively intense. In order to stabilize the group, aryl substitution is often performed on the C-H bond. The substituted heterocyclic structure is more stable, but the electron effect still extends to the substituted substituent group, and the farther the distance from N, the smaller the electron effect. Therefore, the closer the C-H to the nitrogen of pyridine, piperidine, and s-triazine, the greater the vibration, and when deuterium or alkyl substitution is performed, the vibration intensity can be greatly reduced. When there are many substituents on pyridine, piperidine, and s-triazine, only substituting the group that contributes the most to LUMO can also have good performance, achieving the best cost performance. Various pyridine-, piperidine-, and s-triazine-containing compounds have this beneficial effect after being similarly substituted with deuterium or alkyl groups.

[0114] The chemical structure of the first electron transport layer is shown in Formula III:

[0115]

[0116] wherein X1to X3are selected from carbon or nitrogen, and at least one is nitrogen; Y6is a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group; Ar4, Ar5are each independently selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, and the hydrogen on Ar4, Ar5is replaced by deuterium or an alkyl group; L is selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group.

[0117] In one embodiment, the anthracene derivative is selected from X1to X3, Ar4, Ar5, L, Y6are the same as defined above.

[0118] In some embodiments, X1to X3are selected from carbon or nitrogen, and at least one is nitrogen; Y6is selected from a substituted or unsubstituted C6to C30aryl group, or a substituted or unsubstituted C6to C30heterocyclic group; Ar4, Ar5are each independently selected from a substituted or unsubstituted C5to C16aryl group, or a substituted or unsubstituted C5to C16heterocyclic group, and the hydrogen on Ar4, Ar5is replaced by deuterium or an alkyl group; L is selected from a substituted or unsubstituted C6to C12arylene group, or a substituted or unsubstituted C6to C12heterocyclic group. In some specific embodiments, the number of carbon atoms in the aryl or heterocyclic group of Y6may also be 6 to 12, 12 to 18, 18 to 24, 24 to 30, etc. The number of carbon atoms in the aryl or heterocyclic group of Ar4, Ar5may also be 5 to 10, 10 to 16, etc.

[0119] Preferably, in the chemical structure of Formula III, Ar4, Ar5are each independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted benzothiophene group, a substituted or unsubstituted benzofuran group, a substituted or unsubstituted benzoselenophene group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, a substituted or unsubstituted dibenzoselenophene group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted dibenzosilole group; and the hydrogen on Ar4, Ar5is replaced by deuterium or a linear, branched or cyclic alkyl group.

[0120] More preferably, Ar4to Ar5are each independently selected from a phenyl group, a biphenyl group or a naphthyl group, and the hydrogen on Ar4, Ar5is replaced by deuterium, a linear, branched or cyclic C1to C10alkyl group. In some specific embodiments, the number of carbon atoms in the alkyl group may also be 1 to 3, 3 to 5, 5 to 8, or 8 to 10, etc.

[0121] For example, the hydrogen on Ar4, Ar5is replaced by deuterium, a methyl group, a cyclohexane group.

[0122] In some embodiments, L is selected from a substituted or unsubstituted C6to C12arylene group, a substituted or unsubstituted C6to C12heterocyclic group.

[0123] Preferably, L is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted phenylnaphthylene, and the like. Further preferably, L is selected from phenylene, biphenylene, naphthylene, phenylnaphthylene.

[0124] Preferably, some of the hydrogens on L can also be substituted by deuterium, alkyl. The alkyl can be linear, branched or cyclic. For example, it can be linear, branched or cyclic C1-C10 alkyl. Specifically, it can be methyl, cyclohexane, and the like.

[0125] In some embodiments, Y6is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted phenylnaphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dinaphthothiophenyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted triphenylphosphine oxide, substituted or unsubstituted triphenylborane, substituted or unsubstituted benzoxazolyl, and the like. Further, the substituted or unsubstituted fluorenyl can be substituted or unsubstituted 9,9'-dimethylfluorenyl, substituted or unsubstituted 9,9'-dibenzofluorenyl, substituted or unsubstituted 9,9'-spirobifluorenyl, substituted or unsubstituted spiro[fluorene-9,9'-xanthene], and the like.

[0126] Preferably, each Y6is independently selected from phenyl, biphenyl, naphthyl, phenanthryl, anthryl, phenylnaphthyl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, spiro[fluorene-9,9'-xanthene], dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl, triphenylphosphine oxide, triphenylborane, benzoxazolyl, and the like.

[0127] The present application lists some as examples, the compounds shown in formula III can be represented by any of the following formula ET1-ET25 chemical structure:

[0128]

[0129]

[0130] second electron transport layer or third electron transport layer

[0131] The second electron transport layer or the third electron transport layer is generally 10-40 nm thick, which can be achieved in several ways:

[0132] The organic electron transport material is mixed with a metal compound;

[0133] The organic electron transport material is mixed with a metal.

[0134] The organic electron transport material is mixed with a metal compound, for example, an alkali metal compound, an alkaline earth metal compound, a rare earth metal compound, more specifically, a lithium metal compound, a calcium metal compound, a magnesium metal compound, a samarium metal compound, a ytterbium metal compound, and the like, more specifically, a lithium 8-hydroxyquinoline compound, a lithium fluoride compound, a magnesium fluoride compound, a calcium fluoride compound, and the like. When mixed with a metal compound, the mass ratio of the organic electron transport material can be 20% to 80%, 20% to 40%, 40% to 60%, or 60% to 80%, and the like.

[0135] The organic electron transport material is mixed with a metal, for example, an alkali metal, an alkaline earth metal, a rare earth metal, more specifically, a lithium metal, a magnesium metal, a calcium metal, a ytterbium metal, a samarium metal, and the like. When mixed with a metal, the mass ratio of the organic electron transport material can be 80% to 99%, 80% to 89%, 89% to 99%, 80% to 85%, 85% to 90%, 90% to 95%, or 95% to 99%, and the like.

[0136] The compounds of the second electron transport layer or the third electron transport layer are listed as follows:

[0137]

[0138]

[0139] charge generation layer :

[0140] When single light-emitting layer device is used, holes and electrons are injected from anode and cathode respectively, and charge generation layer is not needed. When double or multiple light-emitting layers are used, charge generation layer is needed between light-emitting layers to achieve the effect of charge generation, injection and transmission. Charge generation layer is located between two light-emitting layers, and is generally composed of P / N type two-layer material, P layer material is close to the second light-emitting layer, and N type material is away from the second light-emitting layer. The P type material is selected from the hole injection material described above, and the N type material is mixed with metal by using organic electron transport material. The organic electron transport material is selected from the second electron transport layer or the third electron transport layer described above, and the metal is selected from alkali metal, alkaline earth metal and rare earth metal, and more specifically, lithium metal, magnesium metal, calcium metal, ytterbium metal and samarium metal. The mass ratio of the organic electron transport material mixed with the metal can be 80% to 99%, 80% to 89%, 89% to 99%, 80% to 85%, 85% to 90%, 90% to 95%, or 95% to 99%, etc.

[0141] cathode

[0142] The cathode requires a material with good electrical conductivity and good surface flatness. In order to improve the electron injection capability, a material with small work function is usually selected. The cathode material can be a single-layer cathode or a double-layer or multi-layer cathode, and generally uses metal or metal alloy. For single-layer cathode, silver metal, copper metal, aluminum metal, gold metal or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals and alkaline earth metals, can be used, for example, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-potassium alloy, aluminum-scandium-potassium alloy, magnesium-silver alloy, silver-ytterbium alloy, silver-samarium alloy, etc. If the cathode is a double-layer metal, the cathode close to the light-emitting layer can use alkali metal, alkaline earth metal and rare earth metal, such as lithium, calcium, magnesium and ytterbium, to increase the electron injection capability. The cathode layer away from the light-emitting layer is generally used to improve the conductivity, and can use silver metal, copper metal, aluminum metal, gold metal or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals and alkaline earth metals, which can be listed as magnesium-indium alloy, magnesium-aluminum alloy, aluminum-potassium alloy, aluminum-scandium-potassium alloy, magnesium-silver alloy, silver-ytterbium alloy, silver-samarium alloy, etc. The cathode can also be formed into a thin film by evaporation, sputtering and other methods.

[0143] When light comes out from the anode side, the cathode is required to be opaque, and a cathode with a thickness greater than 100 nm can be evaporated. When light comes out from the cathode side, the cathode is required to be transparent, and the transmittance should be greater than 40% and the thickness is 10-20 nm.

[0144] cover layer

[0145] ​When the light comes out from the cathode side, the resonance of the photon and the electron in the cathode metal reduces the light emitting efficiency. The covering layer added on the side of the cathode far from the light emitting layer can reduce the effect and effectively improve the light efficiency. The material of the covering layer is the material with the refractive index greater than 1.9 at the wavelength of 460 nm and the absorption rate less than 0.05%. The covering layer lists some compounds as follows:

[0146] Another aspect of the present application provides a display device comprising the organic electroluminescent device of the present application.

[0147] Compared with the prior art, the organic electroluminescent device of the present application can obtain high lifetime to a great extent and has relatively low cost by accurately identifying the active site of the excited state and accurately deuterating or alkylating the active site. More importantly, the device has high lifetime at high temperature after the hydrogen of the multi-layer active site is accurately deuterated or alkylated. This method is more economical than the compound used in the full deuterated device and has better performance than the single-layer compound in the only deuterated device.

[0148] The embodiments of the present application are described below through specific examples.

[0149] The synthesis method of the compound BH shown in formula I is as follows:

[0150]

[0151] Synthesis example of BH1:

[0152]

[0153] Synthesis of BH1-3:

[0154] In a 500 mL three-necked flask, BH1-1 (15 g, 50 mmol), BH1-2 (8.6 g, 50 mmol), K2CO3 (13.7 g, 100 mmol), Pd(PPh3)4 (1.1 g, 1 mmol) were sequentially added, and then 150 mL of toluene, 25 mL of ethanol and 25 mL of water were added. The system was replaced with nitrogen for 3 times, the reaction liquid was heated to reflux, and the stirring was continued for 6 hours. The reaction liquid was cooled to 70°C, and was allowed to stand to separate. The upper organic phase was washed with 50 mL of water, and was separated. The upper organic phase was passed through a silica gel column. The organic phase was concentrated to about 70 mL of toluene, 100 mL of petroleum ether was gradually added, and a solid was precipitated. The stirring was continued for 2 hours, and the solid was filtered under suction. The filter cake was washed with a small amount of petroleum ether, and was stirred in a mixture of 60 mL of toluene and 120 mL of ethanol at 40°C for 2 hours. The solid was filtered and dried to obtain 12 g of BH1-3 compound with a yield of 69%.

[0155] Synthesis of BH1:

[0156] In a 500 mL three-necked flask, BH1-3 (10 g, 28.8 mmol), BH1-4 (6.1 g, 28.8 mmol), K2CO3 (7.9 g, 57.6 mmol), Pd(PPh3)4 (0.6 g, 1 mmol) were added in sequence, then 100 mL of toluene, 20 mL of ethanol and 20 mL of water were added, the system was replaced by nitrogen for 3 times, the reaction liquid was heated to reflux, and the stirring was continued for 6 hours. The reaction liquid was cooled to 70 °C, and was allowed to stand to separate into two layers. The upper organic phase was washed with 35 mL of water, and was separated. The upper organic phase was passed through a silica gel column. The organic phase was concentrated to about 50 mL of toluene, 75 mL of petroleum ether was gradually added, a solid was precipitated, and the stirring was continued for 2 hours. The solid was filtered under suction, the filter cake was washed with a small amount of petroleum ether, and the solid was stirred in a mixture of 40 mL of toluene and 80 mL of ethanol at 40 °C for 2 hours. The solid was filtered and dried to obtain 17 g of the BH1 compound, with a yield of 71%.

[0157] Other materials were synthesized by the same method, and different raw materials were used for replacement.

[0158]

[0159]

[0160] The synthesis method of the first hole transport layer adopts a two-step Buchwald arylamine reaction.

[0161] Synthesis Example 13:

[0162]

[0163] Synthesis of compound BP1: In a three-necked flask, BP1-1 (15 g, 78.1 mmol) and NaOBu-t (15 g, 156.2 mmol) were added, then toluene (150 mL) was added, the system was replaced by nitrogen, the reaction liquid was heated to 70 °C, Pd2(dba)3 (0.15 g, 1% w / w) and t-Bu3P (1.5 g, 10% w / w) were added, the system was replaced by nitrogen, and BP1-2 (13.5 g, 78.1 mmol) was dissolved in 30 mL of toluene and was added dropwise slowly. After the dropwise addition was completed, the system was heated to 110 °C, and the reaction was continued for 5 hours. After the reaction was completed, the reaction liquid was cooled to 50 °C, and was passed through silica gel and eluted with 100 mL of toluene. The obtained filtrate was concentrated to a volume of half, 110 mL of ethanol was added, and the stirring was continued at room temperature for 1 hour. After filtration, white solid BP1-3 (18 g, yield 70.0%) was obtained.

[0164] Synthesis of compound BP1 : In a three-neck flask, BP1 -3 (15 g, 45.5 mmol), BP1 -4 (16.3 g, 45.5 mmol), Pd2(dba)3(0.15 g, 1 % w / w), t-Bu3P (1.5 g, 10% w / w), NaOBu-t (8.8 g, 91 mmol) were added, then toluene (150 mL) was added, the system was replaced by nitrogen, the reaction liquid was heated to reflux, the reaction was stirred for 4 h, the reaction liquid was cooled to 80 °C, and then passed through a silica gel column while hot, the mother liquor was concentrated to 80 mL, 100 mL of ethanol was added, stirred at room temperature for 2 h, filtered, 100 mL of toluene was added to the solid, refluxed to dissolve, 100 mL of petroleum ether was added, stirred at room temperature for 2 h, filtered, and dried to obtain white solid BP1 20 g, yield 67.5%.

[0165] Other materials of the first hole transport layer were synthesized by the same method, using different raw materials. The raw materials of Examples 13-24 are shown in Table 2 below:

[0166] Table 2

[0167]

[0168]

[0169] The synthesis of the first electron transport layer material was obtained by Suzuki reaction.

[0170] Synthesis Example 25

[0171]

[0172] Synthesis of ET1 : In a 500 mL three-neck flask, ET1 -1 (15 g, 54 mmol), ET1 -2 (21 g, 54 mmol), K2CO3(14.8 g, 108 mmol), Pd(PPh3)4(1.24 g, 1.08 mmol) were added in turn, then 150 mL of toluene, 25 mL of ethanol and 25 mL of water were added, the system was replaced by nitrogen for 3 times, the reaction liquid was heated to reflux, and the reaction was stirred for 4 hours. The reaction liquid was cooled to 70 °C, and then separated, the upper organic phase was washed with 50 mL of water, separated, and then passed through a silica gel column. The organic phase was concentrated to about 70 mL of toluene, 100 mL of petroleum ether was gradually added, and a solid was precipitated, stirred for 2 hours, filtered, and then washed with a small amount of petroleum ether. The solid was stirred in a mixture of 60 mL of toluene and 120 mL of ethanol at 40 °C for 2 hours, filtered, and then dried to obtain ET1 compound 22 g, yield 69%.

[0173] The synthesis method of other first electron transport layer materials is the same as ET1, except that different raw materials are used. The raw materials of Examples 25-35 are shown in Table 3:

[0174] Table 3

[0175]

[0176]

[0177] Device embodiment:

[0178] The device of the present application can be used with single light emitting layer, multi-layer light emitting layer, some compounds are listed in the present embodiment, which are proved to be effective in device implementation. The present device only describes device implementation for some compounds. Since light emission is from the anode side and from the cathode side, the efficiency of the device is quite different, but the lifetime and stability of the device are basically the same. The main purpose of the present application is to improve the lifetime of the device, so the effect of the device lifetime is exactly the same for different light emission directions, so the device with light emission from the cathode side is used for implementation example. Different device structures have different device lifetime and stability, but after using the scheme of the present application, since the principle is the same, the performance is improved to a similar degree, the present application only lists some device structures for implementation description. The device structures mentioned in the specification are all effective, and the present application only describes the following device structures:

[0179] Device A: anode / hole injection layer / second hole transport layer / first hole transport layer / first light emitting layer / first electron transport layer / second electron transport layer / cathode / cover layer

[0180] Device B: anode / hole injection layer / second hole transport layer / first hole transport layer / first light emitting layer / first electron transport layer / cathode / cover layer

[0181] Embodiment of device A:

[0182] Device A embodiment 1:

[0183] Device fabrication uses the high vacuum thermal evaporation method commonly used in OLED devices, and the film is plated on a glass substrate by heating the material in a vacuum environment with a vacuum degree of less than 10-6 torr. The specific plating process is as follows:

[0184] PD1 and HT1 are mixed and evaporated on the ITO (150 nm) / Ag (100 nm) / ITO (20 nm) glass substrate, and the mass ratio of PD1 and HT1 is 3:97, then 100 nm thick compound HT1 is evaporated to form the second hole transport layer, then 20 nm compound BP1 is evaporated to form the first hole transport layer, then 25 nm compound BH1 and BD1 are evaporated at a ratio of 95:5 to form a blue light emitting layer, then 10 nm ETB1 is evaporated to form the first electron transport layer, then compound ET1 and Liq The second electron transport layer with a thickness of 25 nm is formed in a mixing ratio of 4:6 (mass ratio), followed by evaporation of ytterbium with a thickness of 1 nm, and then evaporation of silver with a thickness of 15 nm as a double-layer ytterbium / silver metal as a cathode, and then evaporation of CPL1 with a thickness of 65 nm as a cover layer.

[0185] It should be noted that the optimal thickness of the thin film is different for different glass substrates, anodes, and materials. The optimal thickness and ratio are also different for different material combinations. In order to reduce the influence of comparative experiments, the same thickness and doping ratio are used. Even if the device is not in the optimal state, the effect of using the scheme of the present application and not using the comparative scheme can be compared. The same comparison method is used for other examples and comparative examples. When the electron transport layer uses an organic electron transport material and a metal, the metal uses Yb, the ratio is 1% to 3%, and the cathode can use a single-layer Ag (90%):Mg (10%).

[0186] The materials of the device A examples and comparative examples are shown in Table 4.

[0187] Table 4

[0188]

[0189]

[0190]

[0191]

[0192] Device B examples:

[0193] The device B examples and the device A examples are made by the same method, except that the device B uses a single-layer electron transport layer with a thickness of 35 nm. The detailed example comparison is as follows:

[0194] The materials of the device B examples and comparative examples are shown in Table 5.

[0195] Table 5

[0196]

[0197] The device B is made in a similar way to the device A, except that the thickness is adjusted. Regardless of the thickness, the device life is improved by the present application.

[0198] The molecular structures used in the device examples and comparative examples are as follows:

[0199]

[0200] Implementation effect:

[0201] OLED light-emitting devices were tested at room temperature and high temperature, and the current density of the devices was 40 mA / cm 2 The LT95 device lifetime refers to the time required for the luminance to decrease to 95% of the initial luminance, and the longer the time, the longer the device lifetime. Each set of example devices was produced and tested in the same batch as the device of Comparative Example 1, and the lifetime of the device of Comparative Example 1 was taken as 100%, and the relative lifetime of each example of Device A was calculated by dividing the lifetime of each example by the lifetime of Comparative Example 1. The raw material cost of the device of Comparative Example 1 was taken as 100%, and the relative cost of the raw material of each example of Device A was calculated by dividing the raw material cost of each example by the raw material cost of Comparative Example 1. As shown in Table 6.

[0202] Table 6

[0203]

[0204]

[0205] Each set of example devices of Device B and Comparative Example was produced and tested in the same batch as the device of Comparative Example 18, and the lifetime of the device of Comparative Example 18 was taken as 100%, and the relative lifetime of each example of Device B was calculated by dividing the lifetime of each example by the lifetime of Comparative Example 18. The raw material cost of the device of Comparative Example 18 was taken as 100%, and the relative cost of the raw material of each example of Device B was calculated by dividing the raw material cost of each example by the raw material cost of Comparative Example 18. As shown in Table 7.

[0206] Table 7

[0207]

[0208] From the results of Table 6 and Table 7, it can be seen that when no deuterium substitution or alkyl substitution is used, the device lifetime is the worst; when all the hydrogen in the molecule is replaced by deuterium, the effect is equivalent to that of the precise deuterium substitution of the present application, but the production cost is very high; when part of the present application is used, the performance is improved compared with no deuterium substitution or alkyl substitution; when non-precise deuterium substitution is used, the device performance is not significantly improved. Therefore, the device of the present application has excellent performance and the highest cost performance, and is very suitable for mass production.

[0209] The above examples are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. An organic electroluminescent device comprising a first electrode and a second electrode, between which an organic layer is arranged, the organic layer comprising at least one or more first hole transport layers, a first light-emitting layer, and a first electron transport layer; the first light-emitting layer is located between the first hole transport layer and the first electron transport layer; the first light-emitting layer is in contact with the first hole transport layer; the first light-emitting layer is in contact with the first electron transport layer; the first light-emitting layer comprises one or more anthracene derivatives, the anthracene derivative comprising a compound as shown in Formula I: wherein Y1-Y2are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted phenanthrenonaphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dinaphthothiophenyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted carbazoyl; the first hole transport layer comprises a triarylamine derivative-containing compound, the triarylamine derivative-containing compound comprising a compound as shown in Formula II: wherein Y3-Y5are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted phenanthrenonaphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dinaphthothiophenyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted carbazoyl, deuterium, methyl, ethyl, propyl, n-propyl, i-propyl, butyl, n-butyl, i-butyl, t-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, i-hexyl, 4-methylhexyl, 5-methylhexyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane; Ar1-Ar3are each independently selected from phenylene or naphthylene; and at least one of the three groups Ar1-Ar3has hydrogen substituted by deuterium or alkyl; the first electron transport layer is selected from a nitrogen-containing heterocyclic compound, and the hydrogen on the ring is substituted by deuterium or alkyl; the first electron transport layer is selected from one or more combinations of a pyridine compound, a piperidine compound, and a s-triazine compound; the first electron transport layer comprises a compound as shown in Formula III: wherein X1-X3 are selected from carbon or nitrogen, and at least one is nitrogen; Y6 is independently selected from phenyl, biphenyl, naphthyl, phenanthryl, anthryl, benzophenanthryl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, spiro[fluorene-9,9'-xanthene], dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl, triphenylphosphine oxide, triphenylborane, benzoxazole; Ar4, Ar5 are independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzoselenophenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dibenzoselenophenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzosilole, and the hydrogen on Ar4, Ar5 is substituted by deuterium or alkyl; L is selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted benzophenanthrylene.

2. The organic electroluminescent device according to claim 1, wherein In the compound of formula I, Y1-Y2 are independently selected from phenyl, biphenyl, naphthyl, phenanthryl, anthryl, benzophenanthryl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl.

3. The organic electroluminescent device according to claim 1, wherein In the compound of formula II, Y3-Y5 are independently selected from phenyl, biphenyl, naphthyl, phenanthryl, anthryl, benzophenanthryl, 9,9'-dimethylfluorenyl, 9,9'-dibenzofluorenyl, 9,9'-spirobifluorenyl, dibenzofuranyl, dinaphthofuranyl, naphthobenzofuranyl, dibenzothiophenyl, dinaphthothiophenyl, naphthobenzothiophenyl, carbazolyl, deuterium, methyl, cyclohexane.

4. The organic electroluminescent device according to claim 1, wherein In the compound of formula III, Ar4, Ar5 are independently selected from phenyl, biphenyl or naphthyl; and the hydrogen on Ar4, Ar5 is substituted by deuterium, linear, branched or cyclic C1-C10 alkyl; and / or, L is selected from phenylene, biphenylene, naphthylene, benzophenanthrylene; and / or, part of the hydrogen on L can also be substituted by deuterium or alkyl.

5. The organic electroluminescent device according to claim 1, wherein The compound of formula I can be represented by any of the following chemical structures of formula BH1-BH12:

6. The organic electroluminescent device according to claim 1, wherein The compound of formula II can be represented by any of the following chemical structures of formula BP1-BP30:

7. The organic electroluminescent device according to claim 1, wherein The compound of formula III can be represented by any of the following chemical structures of formula ET1-ET25:

8. The organic electroluminescent device according to claim 1, wherein The first light-emitting layer comprises an anthracene derivative and a dopant material, and the weight percentage of the anthracene derivative in the light-emitting layer is 95%-99%. and / or, the first light-emitting layer comprises two different anthracene derivatives and a dopant material, and the total weight percentage of the two anthracene derivatives in the light-emitting layer is 95%-99%.

9. The organic electroluminescent device according to claim 1, wherein A hole injection layer is arranged between the first electrode and the first hole transport layer; and the first electrode is an anode.

10. The organic electroluminescent device according to claim 9, wherein A second hole transport layer is arranged between the hole injection layer and the first hole transport layer; and / or, a second light-emitting layer is further included, the first hole transport layer is two layers, and a second light-emitting layer and a charge generation layer are further arranged between the two layers of the first hole transport layer in sequence; and / or, an electron injection layer is further included, and the electron injection layer is arranged between the first electron transport layer and the second electrode; and / or, a second electron transport layer is further included, and the second electron transport layer is arranged between the first electron transport layer and the second electrode; and / or, the second electrode is selected from one or more cathodes.

11. The organic electroluminescent device according to claim 10, wherein The second light-emitting layer includes at least one or more anthracene derivatives, and the anthracene derivative is a compound as shown in Formula I; and / or, a third electron transport layer is further included, and the third electron transport layer is arranged between the second electron transport layer and the second electrode; and / or, the light-emitting direction is from the cathode side, and a cover layer is arranged on the side of the cathode side away from the first electron transport layer.

12. A display device comprising the organic electroluminescent device according to any one of claims 1 to 11.

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