Organic electroluminescent device and electronic device

Abstract

The application discloses an organic electroluminescent device and an electronic device. The organic electroluminescent device comprises a cathode, an anode and an organic layer formed between the cathode and the anode, wherein the organic layer comprises a hole injection layer, a hole transport layer, a first light-emitting auxiliary layer, a second light-emitting auxiliary layer and a light-emitting layer, etc. The first light-emitting auxiliary layer and the second light-emitting auxiliary layer are selected from different amino compound materials, but the two types of materials have specific structural characteristics and both contain fluorene groups. The two light-emitting auxiliary layers have different refractive indexes, thereby constructing an effective energy level gradient and a refractive index gradient between the organic layers of the device, smoothly injecting holes into the light-emitting layer, optimizing the light field distribution in the device through the refractive index change of the organic layer on the basis of ensuring the hole transport efficiency, improving the light extraction efficiency of the device and realizing good device performance.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, specifically relating to an organic electroluminescent device and electronic apparatus. Background Technology

[0002] Due to their simple structure, low driving voltage, and ability to achieve large-area displays, organic light-emitting diodes (OLEDs) have been widely used in the field of lighting. In OLEDs, holes and electrons are injected from the anode and cathode, respectively, and meet in the light-emitting layer to form excitons, which then emit light to achieve the purpose of display. However, OLEDs have various light loss mechanisms, and most photons are lost internally, with only a small portion of the light energy escaping into the air. This results in an external quantum efficiency that is much lower than the internal quantum efficiency.

[0003] To improve light extraction efficiency, existing technologies generally optimize device performance through material improvements and device structure modifications. Among these, the design of optimizing light extraction efficiency by introducing matching organic layers with different refractive indices has attracted attention in recent years. For example, patent documents such as CN116761868A, entitled "Organic Electroluminescent Element, Organic Electroluminescent Display Device and Electronic Device," involve research on the combination of organic layers with different refractive indices within the device, and this research direction still has considerable room for development. Summary of the Invention

[0004] The technical objective of this invention is to develop new organic electroluminescent devices based on the technical concept of changes in the refractive index of organic layers.

[0005] The technical solution provided by this invention includes: An organic electroluminescent device includes a cathode, an anode, and an organic layer formed between the cathode and the anode. The organic layer includes a light-emitting layer, and a hole injection layer, a hole transport layer, and a plurality of light-emitting auxiliary layers sequentially disposed between the anode and the light-emitting layer.

[0006] The plurality of light-emitting auxiliary layers include a first light-emitting auxiliary layer and a second light-emitting auxiliary layer, wherein the material of the first light-emitting auxiliary layer near the hole transport layer is selected from a compound of formula 1 or a compound of formula 1 further substituted with deuterium, and the material of the second light-emitting auxiliary layer near the light-emitting layer is selected from a compound of formula 3. ; In Formula 1, Ar1 is selected from C6-C20 aryl groups, L is selected from groups as shown in Formula 2, and R1 in Formula 1 and R2 in Formula 2 each independently represent hydrogen, C1-C4 alkyl or C6-C12 aryl groups. ; In Formula 3, Ar2 is selected from C5-C18 heteroaryl groups, R3, R4 and R5 each independently represent C1-C4 alkyl groups that are substituted with deuterium or not, D represents deuterium, and n is an integer selected from 0-4.

[0007] Based on the above solutions, even better technical solutions include: Furthermore, in Formulas 1, 2, and 3, the C1-C4 alkyl group is methyl, isopropyl, or tert-butyl.

[0008] Furthermore, in Formula 1, Ar1 is selected from phenyl, biphenyl, and naphthyl.

[0009] Furthermore, in Formula 2, the Ar2 group contains heteroatoms of O or S.

[0010] Furthermore, in the organic electroluminescent device of the present invention, the compound of formula 1 is represented by formula 1-1 or 1-2: ; In Formulas 1-1 and 1-2, Ar1 is selected from C6-C20 aryl groups, and R1 and R2 represent hydrogen, C1-C4 alkyl or C6-C12 aryl groups.

[0011] Furthermore, in Formula 1, the L group is preferably connected to the 2nd or 3rd site of the adjacent dimethylfluorene.

[0012] Furthermore, in the organic electroluminescent device of the present invention, the compound of Formula 1 is selected from the following compounds: .

[0013] Furthermore, in the organic electroluminescent device of the present invention, the compound of formula 3 is selected from the following compounds: .

[0014] Furthermore, in the organic electroluminescent device of the present invention, the refractive index of the first light-emitting auxiliary layer is less than that of the second light-emitting auxiliary layer, the refractive index of the first light-emitting auxiliary layer material is ≤1.80, and the difference in refractive index between the first light-emitting auxiliary layer material and the second light-emitting auxiliary layer material is not less than 0.02.

[0015] An electronic device comprising an organic electroluminescent device as described in any of the preceding claims.

[0016] Beneficial effects: This invention relates to an organic electroluminescent device that employs a multi-emissive auxiliary layer design. The first and second emissive auxiliary layers are made of different amino compound materials, but both materials have specific structural characteristics and contain fluorene groups. The two emissive auxiliary layers have different refractive indices, thereby creating an effective energy level gradient and refractive index gradient between the organic layers of the device. This allows for the smooth injection of holes into the emissive layers. While ensuring hole transport efficiency, the change in the refractive index of the organic layers optimizes the light field distribution inside the device, improving the light extraction efficiency and achieving excellent device performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device provided by the present invention; Figure 2 This is the HPLC spectrum of compound 1; Figure 3 This is the HPLC spectrum of compound 2; Figure 1 The reference numerals in the figures represent: 1-anode, 2-hole injection layer, 3-hole transport layer, 4-first light-emitting auxiliary layer, 5-second light-emitting auxiliary layer, 6-light-emitting layer, 7-hole blocking layer, 8-electron transport layer, 9-electron injection layer, and 10-cathode. Detailed Implementation

[0018] The following further illustrates and describes various aspects of the invention. It should be understood that the following description is not intended to limit the claims to the specific aspects described. Rather, it is intended to cover substitutions, modifications, and equivalents that may be included within the scope defined by the appended claims.

[0019] In this document, the term "substituted or unsubstituted" refers to the recoordination of at least one hydrogen atom of a group with a substituent group such as deuterium. The term "aryl" in this document refers to a group containing one or more aromatic rings, including but not limited to benzene, naphthalene, phenanthrene, fluorene, and acenaphthene. The term "heteroaryl" in this document refers to a heteroaryl group obtained by substituting one or more carbon atoms in the structure of an "aryl" group with one or more heteroatoms (such as N, O, or S), including but not limited to pyridine, pyrimidine, pyrrole, furan, thiophene, dibenzofuran, dibenzothiophene, and carbazole.

[0020] The terms C6-C20, C5-C18, and C1-C4 in the text indicate that the modified groups contain 6-20, 5-18, and 1-4 carbon atoms, respectively. If the corresponding groups can be substituted, C6-C20, C5-C18, and C1-C4 here do not include the number of carbon atoms of the substituents.

[0021] In this invention, "deuterium" refers to a stable isotope of hydrogen, also known as heavy hydrogen, and its element symbol is D.

[0022] Unless otherwise specified in the following synthesis examples, the synthesis should be carried out under standard conditions or the manufacturer's recommended conditions. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0023] I. Material Synthesis 1. Synthesis of the first light-emitting auxiliary layer material 1.1 Synthesis of Compound 1 1) Synthetic route ; 2) Synthesis steps S1: Under nitrogen protection, compound 1-a (1 eq, 27.32 g, 273.17 g / mol, 0.1 mol), compound 1-b (1.05 eq, 16.42 g, 156.37 g / mol, 0.105 mol), potassium carbonate (2 eq, 27.64 g, 138.21 g / mol, 0.2 mol), tetraphenylphosphine palladium (0.02 eq, 2.31 g, 1155.56 g / mol, 2 mmol), and toluene / ethanol / water (270 ml + 135 ml + 81 ml) were added to a reaction flask. After the addition was complete, the mixture was heated to 85 °C and stirred for 24 h. After the reaction was complete, the mixture was cooled to room temperature, and 100 ml of water was added. The mixture was stirred and separated, and the aqueous phase was separated using 100 ml of water. DCM extraction, combined organic phases, filtered through silica gel, concentrated the filtrate to dryness under reduced pressure, added n-heptane (100 ml) and heated to dissolve, then cooled to -20℃ and stirred to crystallize for 2 h, filtered the solid, dried at 65℃ to give compound 1-c (22.43 g, yield 73.6%).

[0024] S2: Under nitrogen protection, compounds 1-c (1 eq, 22 g, 304.82 g / mol, 72.17 mmol), 1-d (1 eq, 26.1 g, 361.49 g / mol, 72.17 mmol), sodium tert-butoxide (1.5 eq, 10.4 g, 96.1 g / mol, 108.26 mmol), XPhos (0.04 eq, 1.38 g, 476.72 g / mol, 2.8868 mmol), palladium acetate (0.02 eq, 0.32 g, 224 g / mol, 1.4434 mmol), and toluene (220 g / mol) were mixed. Add mL to the reaction flask. After the addition is complete, heat to 110℃ and stir for 3 hours. After the reaction is complete, filter the mixture while hot through silica gel. Wash the filter cake with dichloromethane. Concentrate the filtrate under reduced pressure to dryness. Add toluene (100 ml) and heat to dissolve. Add ethanol (200 ml) and cool to room temperature for 2 hours to crystallize. The filtered solid is recrystallized twice with toluene (80 ml) + ethanol (160 ml). The filtered solid is dried at 85℃ to obtain compound 1 (31.5 g, yield 69.3%). ESI-MS (m / z, [M+H]+): theoretical value 630.32, measured value 630.35.

[0025] 1.2. Synthesis of Compound 2 1) Synthetic route ; 2) Synthesis steps Following the same preparation method as compound 1, and using the same synthetic route as above, compound 2 was obtained (yield 65.9%). ESI-MS (m / z, [M+H]+): theoretical value 630.32, measured value 630.33.

[0026] 1.3. Synthesis of Compound 3 1) Synthetic route ; 2) Synthesis steps Following the same synthetic route as compound 1, compound 3 (yield 66.8%) was obtained by ESI-MS (m / z, [M+H)). + Theoretical value: 630.32, measured value: 630.36.

[0027] 1.4. Synthesis of other compounds Other compounds used in the first luminescent auxiliary layer can be obtained by referring to the preparation method of compound 1, and will not be listed here one by one.

[0028] 2. Synthesis of the second light-emitting auxiliary layer 2.1 Synthesis of Compound 75 1) Synthetic route ; 2) Synthesis steps S1: Under nitrogen protection, compound 75-a (1 eq, 20 g, 195.42 g / mol, 102.34 mmol) and ultra-dry THF (200 mL) were added to a reaction flask. The mixture was cooled to below -65 °C, and n-butyllithium (1.05 eq, 43 mL, 2.5 mol / L, 107.46 mmol) was added dropwise. After the addition was complete, the mixture was kept at this temperature and stirred for 1 h. Then, 78-b (0.95 eq, 17.52 g, 180.21 mmol) was added dropwise. Add 88 ml of ultradry THF (g / mol, 97.22 mmol) and control the internal temperature to not exceed -60 °C. After the addition is complete, move to room temperature and stir for 1 h. After the reaction is complete, add 300 ml of saturated ammonium chloride aqueous solution and stir to quench. Separate the liquid and extract the aqueous phase with dichloromethane (200 ml). Combine the organic phases, dry with anhydrous sodium sulfate, and concentrate to dryness to obtain compound 75-c (32.7 g, over-yield). Without purification, it is used directly in the next reaction.

[0029] S2: Under nitrogen protection, compound 75-c (1 eq, theoretical 28.85 g, 296.73 g / mol, 97.22 mmol), triethylsilane (1.5 eq, 16.96 g, 116.28 g / mol, 145.83 mmol), and dichloromethane (300 ml) were added to a reaction flask. The mixture was cooled to -10 °C, and trifluoroacetic acid (3 eq, 33.26 g, 114.02 g / mol, 291.66 mmol) was added dropwise. After the addition was complete, the mixture was moved to room temperature and reacted for 3 h. After the reaction was complete, the mixture was concentrated to dryness, and n-heptane (200 ml) was added and stirred for 2 h. A solid precipitated, which was filtered. The filter cake was washed with water and dried at 65 °C with forced air to obtain compound 75-d (23.33 g, two-step yield 85.5%).

[0030] S3: Under nitrogen protection, compound 75-d (1 eq, 23.33 g, 280.73 g / mol, 83.1 mmol) and ultradry THF (200 mL) were added to a reaction flask. The mixture was cooled to below -20 °C, and 60% sodium hydride (3 eq, 10 g, 24 g / mol, 249.31 mmol) was added in portions. After the addition was complete, the mixture was heated to 45 °C and reacted for 1 h. The mixture was then cooled to below -20 °C, and deuterated iodomethane (1.5 eq, 18.07 g, 144.96 g / mol, 124.66 mmol) was added dropwise. After the first addition of mmol, the mixture was moved to room temperature and stirred for 1 hour. After the reaction was complete, the temperature was lowered to below -10°C, and water (500 ml) was slowly added dropwise until no more bubbles were generated. The mixture was separated, and the aqueous phase was extracted once with dichloromethane (250 ml). The organic phases were combined and concentrated to dryness. Heptane (200 ml) was added and stirred to induce crystallization. The mixture was filtered, and the filter cake was dried at 65°C to obtain compound 75-e (21.4 g, yield 86.5%).

[0031] S4: Under nitrogen protection, compound 75-e (1 eq, 21.4 g, 297.72 g / mol, 71.88 mmol), compound 78-f (1 eq, 13.17 g, 183.21 g / mol, 71.88 mmol), sodium tert-butoxide (1.5 eq, 10.36 g, 96.1 g / mol, 107.82 mmol), 10% tri-tert-butylphosphine toluene solution (0.04 eq, 5.8 ml, 202.32 g / mol, 2.88 mmol), tris(dibenzylacetone)palladium (0.02 eq, 1.32 g, 915.7 g / mol, 1.44 mmol), and toluene (200 ml) were mixed. Add 200 mL of ethanol to the reaction flask. After the addition is complete, heat to 110 °C and stir for 3 h. After the reaction is complete, filter the mixture through silica gel while hot. Wash the filter cake with toluene. Concentrate the filtrate under reduced pressure to dryness. Add 200 mL of ethanol, heat to dissolve, cool to room temperature and stir to crystallize for 1 h. Filter the mixture and dry the filter cake at 85 °C with forced air to obtain 75 g of the compound (24.54 g, yield 76.8%).

[0032] S5: Under nitrogen protection, compound 75-g (1 eq, 24.54 g, 444.48 g / mol, 55.21 mmol), compound 78-h (1 eq, 15.41 g, 279.2 g / mol, 55.21 mmol), sodium tert-butoxide (1.5 eq, 7.96 g, 96.1 g / mol, 82.82 mmol), 10% tritert-tert-butylphosphine toluene solution (0.04 eq, 4.5 ml, 202.32 g / mol, 2.21 mmol), tris(dibenzylacetone)palladium (0.02 eq, 1.01 g, 915.7 g / mol, 1.1 mmol), and toluene (250 mg / mL) were mixed. Add mL of the mixture to the reaction flask. After the addition is complete, heat to 110℃ and stir for 3 hours. After the reaction is complete, filter the mixture while hot through silica gel. Wash the filter cake with dichloromethane. Concentrate the filtrate under reduced pressure to dryness. Add toluene (100 mL) and heat to dissolve the solid. Add ethanol (400 mL) and cool to room temperature for 2 hours to allow crystallization. Recrystallize the filtered solid twice with toluene (50 mL) + ethanol (200 mL). Dry the filtered solid at 85℃ to give compound 75 (24.45 g, yield 68.9%). ESI-MS (m / z, [M+H)) + Theoretical value: 643.36, measured value: 643.38.

[0033] 2.2 Synthesis of Compound 74 1) Synthetic route ; Following the same synthetic route as compound 75, compound 74 was obtained (yield 72.4%). ESI-MS (m / z, [M+H]) was performed. + Theoretical value: 637.33, measured value: 637.30.

[0034] 2.3. Synthesis of other compounds Other compounds used for the second luminescent auxiliary layer can be prepared by referring to the preparation method of compound 75, and will not be listed here one by one.

[0035] II. Device Testing 1. Application Examples 1.1 Application Example 1 ITO / Ag / ITO was used as the anode substrate material for the reflective layer, and its surface was treated sequentially with water, acetone, and N2 plasma. A hole injection layer (HIL) was formed by depositing 10 nm of HT-1 doped with 5% NDP-9 on top of the ITO / Ag / ITO anode substrate. A hole transport layer (HTL) is formed by vacuum evaporating 100 nm of HT-1 above the hole injection layer (HIL); A first light-emitting auxiliary layer (GPL) is formed by vacuum evaporating 20 nm of the low-refractive-index compound 1 of the present invention above the hole transport layer (HTL); A second light-emitting auxiliary layer (GPL') is formed by vacuum evaporating 20 nm of the high-refractive-index compound 74 of the present invention above the first light-emitting auxiliary layer (GPL); GH-1 and GH-2 were used as the main light-emitting materials (the mass ratio of GH-1 and GH-2 was 5:5), and GD-1 was used as the light-emitting dopant (the amount of GD-1 was 4% of the total weight of GH-1 and GH-2). They were co-deposited on the second light-emitting auxiliary layer (GPL') to form a light-emitting layer (EML) with a thickness of 40 nm. HB-1 was deposited onto the light-emitting layer (EML) to obtain a hole blocking layer (HBL) with a thickness of 5 nm. ET-1 and LiQ were co-deposited onto the hole blocking layer (HBL) at a mass ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 30 nm. Ytterbium (Yb) is vapor-deposited onto the electron transport layer (ETL) to form an electron injection layer (EIL) with a thickness of 1 nm; Magnesium (Mg) and silver (Ag) are mixed in a mass ratio of 1:9 and vapor-deposited onto the electron injection layer (EIL) to form a cathode with a thickness of 12 nm. A CP-1 layer with a thickness of 60 nm is deposited on the cathode sealing layer to form a light extraction layer (CPL). Finally, the device surface is sealed with a UV-curable adhesive and a sealing film containing a desiccant to protect the organic electroluminescent device from the influence of oxygen or moisture in the atmosphere. Thus, an organic electroluminescent device is prepared.

[0036] 1.2. Application Example 2-7 With all other conditions being the same as in Application Example 1, the material of the first light-emitting auxiliary layer was replaced with compound 2, compound 3, compound 13, compound 37, compound 45 and compound 71, respectively, to obtain the organic electroluminescent devices of Application Examples 2 to 7.

[0037] 1.3. Application Example 8-14 With all other conditions the same as in Application Example 1, the material of the first light-emitting auxiliary layer was replaced with compound 1, compound 2, compound 3, compound 13, compound 37, compound 45 and compound 71 respectively, and the compound of the second light-emitting auxiliary layer was replaced with compound 75, thus obtaining the organic electroluminescent devices of Application Examples 8 to 14.

[0038] 1.4. Application Examples 15-20 With all other conditions being the same as in Application Example 1, the materials of the first light-emitting auxiliary layer and the second light-emitting auxiliary layer were replaced with compounds 1 and 73, 6 and 76, 13 and 77, 15 and 78, 41 and 79, and 45 and 80, respectively, to obtain the organic electroluminescent devices of Application Examples 15 to 20.

[0039] In addition to the compounds of this invention, other compounds involved in the test systems of the above application examples are shown in Table 1 below: Table 1

[0040] 2. Comparative Example Based on Application Example 1, compound 1, compound 13, compound 37, compound 45, compound 74 and compound 75 were used to separately deposit the light-emitting auxiliary layer of the device with a thickness of 40 nm, which is equal to the sum of the thicknesses of the first and second light-emitting auxiliary layers in Application Example 1, to replace the first and second light-emitting auxiliary layers in the device of Application Example 1, thereby obtaining the organic electroluminescent devices of Comparative Examples 1-6.

[0041] 3. Test Results At a current density of 10 mA / cm 2 Under the specified conditions, the operating characteristics of the organic electroluminescent devices prepared in each application example and comparative example were tested, including key parameters such as start-up voltage, luminous efficiency, and luminous lifetime. The test results are shown in Tables 2 and 3 below: Table 2

[0042] In Table 3, the T97% data refers to the relative time it takes for the device's luminance to decrease to 97% of its initial luminance. The test results are based on the device lifetime data in Comparative Example 1. Table 3

[0043] The devices of this invention all have dual light-emitting auxiliary layers. The first light-emitting auxiliary layer is composed of an amino compound containing aryl and at least two fluorene groups, and the second light-emitting auxiliary layer is composed of another amino compound containing heteroaryl and at least two fluorene groups. The stacked light-emitting auxiliary layers formed by the two types of amino compounds work synergistically to construct a stepped energy level delivery channel, allowing holes to be smoothly injected from the anode into the light-emitting layer. This results in good hole transport efficiency and electron blocking capability in the hole transport region, which is beneficial for maintaining the steady-state balance of charge carriers in the device. Furthermore, in the devices of this invention, there is a difference in refractive index between the first and second light-emitting auxiliary layers. Specifically, in the above application examples, the refractive index of the first light-emitting auxiliary layer is lower than that of the second light-emitting auxiliary layer. As a preferred embodiment, it is recommended to control the refractive index of the first light-emitting auxiliary layer to be ≤1.80, and the difference between the refractive index of the first and second light-emitting auxiliary layers to be not less than 0.02. The refractive index refers to the measurement value at a wavelength of 530 nm.

[0044] As can be seen from the test data in Tables 2 and 3, under the same test system, compared with devices using a single material for the light-emitting auxiliary layer, the device in the application example of this invention has improved performance in many aspects, including a reduction in startup voltage, an increase in luminous efficiency, and a trend towards a longer luminous lifetime. This verifies that the design of this invention, which focuses on the combination of materials for the light-emitting auxiliary layer, has achieved optimization of device performance.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An organic electroluminescent device, comprising a cathode, an anode, and an organic layer formed between the cathode and the anode, said organic layer comprising a light-emitting layer, and a hole injection layer, a hole transport layer, and a plurality of light-emitting auxiliary layers sequentially disposed between the anode and the light-emitting layer, characterized in that: The plurality of light-emitting auxiliary layers include a first light-emitting auxiliary layer and a second light-emitting auxiliary layer, wherein the material of the first light-emitting auxiliary layer near the hole transport layer is selected from a compound of formula 1 or a compound of formula 1 further substituted with deuterium, and the material of the second light-emitting auxiliary layer near the light-emitting layer is selected from a compound of formula 3. ； In Formula 1, Ar1 is selected from C6-C20 aryl groups, L is selected from groups as shown in Formula 2, and R1 in Formula 1 and R2 in Formula 2 each independently represent hydrogen, C1-C4 alkyl or C6-C12 aryl groups. ； In Formula 3, Ar2 is selected from C5-C18 heteroaryl groups, R3, R4 and R5 each independently represent C1-C4 alkyl groups that are substituted with deuterium or not, D represents deuterium, and n is an integer selected from 0-4.

2. The organic electroluminescent device as described in claim 1, characterized in that, In Formulas 1, 2 and 3, the C1-C4 alkyl group is methyl, isopropyl or tert-butyl.

3. The organic electroluminescent device as described in claim 1, characterized in that, In Formula 1, Ar1 is selected from phenyl, biphenyl and naphthyl.

4. An organic electroluminescent device as described in claim 1, characterized in that, In Formula 2, the Ar2 group contains heteroatoms of O or S.

5. An organic electroluminescent device as described in claim 1, characterized in that, The compound of Formula 1 is represented by Formula 1-1 or 1-2: ； In Formulas 1-1 and 1-2, Ar1 is selected from C6-C20 aryl groups, and R1 and R2 represent hydrogen, C1-C4 alkyl or C6-C12 aryl groups.

6. An organic electroluminescent device as described in claim 1, characterized in that, In Formula 1, the L group is connected to the 2nd or 3rd site of the adjacent dimethylfluorene.

7. An organic electroluminescent device as described in claim 1, characterized in that, The compound of Formula 1 is selected from the following compounds: 。 8. An organic electroluminescent device as described in claim 1, characterized in that, The compound of formula 3 is selected from the following compounds: 。 9. An organic electroluminescent device as described in claim 1, characterized in that, The refractive index of the first light-emitting auxiliary layer is less than that of the second light-emitting auxiliary layer, the refractive index of the first light-emitting auxiliary layer material is ≤1.80, and the difference in refractive index between the first light-emitting auxiliary layer material and the second light-emitting auxiliary layer material is not less than 0.

02.

10. An electronic device, characterized in that, The organic electroluminescent device includes any one of claims 1-9.

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