Organic compound having multiple heteroatoms, and organic electroluminescent device comprising same

Abstract

Disclosed herein are an organic compound having multiple heteroatoms and an organic electroluminescent device comprising same. The general structural formula of the organic compound is shown in formula (I), wherein R1-R4 each independently denote any one of hydrogen, deuterium, a substituted or unsubstituted alkyl having a carbon atom number of C1-C30, a substituted or unsubstituted aryl having a carbon atom number of C6-C60, a substituted or unsubstituted fused aryl having a carbon atom number of C6-C60, and a group of formula (II), and at least two of R1-R4 denote the group of formula II. Phosphine oxide and phenanthroline structures are introduced into the structure of the organic compound provided herein. With the introduction of nitrogen, oxygen, phosphine, and other highly electronegative atoms, the organic compound possesses a lower maximum negative electrostatic potential, which is beneficial to improving the stability and electron transport ability of the nCGL material, thereby effectively reducing the driving voltage of the prepared organic electroluminescent device and improving the luminous efficiency and service life.

Description

An organic compound having multiple heteroatoms and an organic electroluminescent device comprising the same. Technical Field

[0001] This invention belongs to the field of OLED technology, specifically including an organic compound having multiple heteroatoms and an organic electroluminescent device containing the same. Background Technology

[0002] To improve the luminous brightness and luminous efficiency of organic light-emitting devices (OLEDs), stacked OLED devices, which utilize multiple OLED light-emitting units connected in series, are becoming a new research trend. Compared to a single OLED light-emitting unit, stacked OLED devices typically exhibit higher current efficiency, luminous brightness, and lifetime.

[0003] In stacked OLED devices, two independent light-emitting units are connected in series via a charge generation layer (CGL). The charge generation layer is typically constructed using a pn structure, and its stability significantly impacts device lifetime and driving voltage. Traditional n-type charge generation layers often employ nCGL materials doped with low work function metals (such as Li, Mg, and Yb) to form complexes. However, the currently developed nCGL materials suffer from poor thermal stability and low electron transport efficiency, which further degrades device stability after metal doping, thus hindering the commercialization of stacked devices.

[0004] Currently, mainstream nCGL materials are mainly based on nitrogen-containing heterocyclic ring structures such as pyridine, pyrimidine, and phenanthroline. These structures can no longer meet the ever-increasing technological requirements in terms of electron transport capabilities. Furthermore, some publicly disclosed phosphine- and phenanthroline-containing nCGL materials also suffer from instability in metal coordination and poor thermal stability. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the present invention provides an organic compound having multiple heteroatoms and an organic electroluminescent device containing the same.

[0006] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0007] A first aspect of the present invention provides an organic compound having a plurality of heteroatoms, the general structural formula of which is shown in Formula I:

[0008] R1-R4 each independently represent any one of hydrogen, deuterium, substituted or unsubstituted alkyl with C1-C30 carbon atoms, substituted or unsubstituted aryl with C6-C60 carbon atoms, substituted or unsubstituted fused-ring aryl with C6-C60 carbon atoms, or the group shown in Formula II, and at least two of R1-R4 represent the group shown in Formula II.

[0009] L1-L4 each independently represent any one of the following: a single bond, a substituted or unsubstituted aryl group with 6-60 carbon atoms, a substituted or unsubstituted heteroaryl group with 5-60 carbon atoms, a substituted or unsubstituted fused-ring aryl group with 6-60 carbon atoms, or a substituted or unsubstituted heterofused-ring aryl group with 5-60 carbon atoms.

[0010] Furthermore, R1 and R2 each independently represent the group shown in Formula II, while R3 and R4 do not represent the group shown in Formula II.

[0011] Furthermore, R3 and R4 each independently represent the group shown in Formula II, while R1 and R2 do not represent the group shown in Formula II.

[0012] Furthermore, each of L1-L4 independently represents a single bond, Any one of them.

[0013] Furthermore, each of L1-L4 independently represents one of the following structures:

[0014] Furthermore, R1 and R2 represent the same group, R3 and R4 represent the same group, L1 and L2 represent the same group, and L3 and L4 represent the same group. That is, when the structure of Formula I is a symmetrical structure, it is more effective in reducing the maximum negative electrostatic potential (ESP) of the material, improving the stability of the material after metal doping, improving the electron transport capability of the material, and improving the device voltage and device life.

[0015] Furthermore, the organic compound is selected from one of the following structures:

[0016] Furthermore, the organic compound is selected from one of the following structures:

[0017] A second aspect of the present invention provides an organic electroluminescent device comprising, sequentially disposed on a substrate, an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation region, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a capping layer; wherein the charge generation region comprises one or more organic compounds as described above.

[0018] Furthermore, the charge generation region includes an n-type charge generation layer and a p-type charge generation layer, wherein the n-type charge generation layer includes one or more organic compounds as described above.

[0019] Beneficial effects of this invention:

[0020] In the development of the nCGL material of this invention, according to Pauling's rule, by using a phosphine + phenanthroline structural combination in the nCGL material, the maximum negative electrostatic potential (ESP) of the nCGL material is significantly reduced by utilizing highly electronegative atoms such as nitrogen, oxygen, and phosphine. When used in combination with low electronegativity n-doped metals, the stability of the device film layer after metal doping of the nCGL material is improved, the electron transport capability of the nCGL material is enhanced, and the device voltage and device lifetime are improved. Furthermore, the increase in electronegativity can reduce the electron injection barrier, increase the electron mobility of the nCGL layer, and thus reduce the driving voltage. Further, when the nCGL material exhibits axisymmetric structural characteristics, it is even more advantageous for improving the electron transport capability of the material and improving the device voltage and device lifetime. In addition, in the structural design, attention is paid to adding spacer groups (i.e., L1-L4) among multiple electron-withdrawing groups to avoid a decrease in material stability caused by the concentration of electron-withdrawing groups. Attached Figure Description

[0021] Figure 1 is a schematic diagram of the structure of the organic electroluminescent device of the present invention. Detailed Implementation

[0022] To better understand the content of this invention, it will be described in detail with reference to the accompanying drawings and embodiments.

[0023] The organic compounds of this invention are applicable to light-emitting elements, display panels, and electronic devices, particularly organic electroluminescent devices. The electronic device described in this invention is a device comprising a layer of at least one organic compound; the device may also comprise a layer of inorganic materials or be entirely composed of inorganic materials. The electronic device is preferably an organic electroluminescent device (OLED). A schematic diagram of an exemplary organic electroluminescent device is shown in Figure 1.

[0024] Experimental Section

[0025] To better understand the content of this invention, the organic compound, the preparation method of the organic compound, and the luminescent properties of the device will be explained in detail with reference to embodiments. Various chemical reactions can be applied to the synthesis method of the compound according to one embodiment of this invention. However, it should be noted that the synthesis method of the compound according to one embodiment of this invention is not limited to the synthesis method described below. Unless otherwise stated, subsequent synthesis is carried out in an anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0026] Synthesis Examples

[0027] In the structure described in this patent, if the substituents on both sides of the phenanthroline are the same, the target product can be obtained in one step by using Suzuki coupling. The chemical reaction equation is as follows:

[0028] If the substituents on both sides of phenanthroline are different, the target product is obtained through two-step Suzuki coupling, and the chemical reaction equation is as follows:

[0029] Synthesis Example 1

[0030] A1 (8.0 g, 20 mmol), B1 (16.2 g, 40 mmol), and potassium carbonate (8.2 g, 60 mmol) were added to 300 mL of a toluene:water mixture of 4:1 (v / v). Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (2.3 g, 2 mmol) was introduced. The reaction mixture was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by petroleum ether:dichloromethane column chromatography (1:1 (v / v)). The final product, C1, was obtained: 13.7 g, yield: 77%, MS (m / z) (M+): 886.

[0031] Synthesis Example 2

[0032] Using the same method as in Synthesis Example 1, A1 and B1 were replaced with A2 (5 g, 20 mmol) and B2 (16.2 g, 40 mmol) to finally obtain product C2: 10.5 g, yield: 71%, MS (m / z) (M+): 734.

[0033] Synthesis Example 3

[0034] Using the same method as in Synthesis Example 1, A1 and B1 were replaced with A3 (8 g, 20 mmol) and B3 (18.2 g, 40 mmol) to finally obtain product C3: 15.7 g, yield: 80%, MS (m / z) (M+): 986.

[0035] Synthesis Example 4

[0036] A4-1 (8.0 g, 20 mmol), B4-1 (8.1 g, 20 mmol), and potassium carbonate (4.1 g, 30 mmol) were added to 300 mL of a toluene:water mixture of 4:1 (v / v). Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (1.2 g, 1 mmol) was introduced. The reaction mixture was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by petroleum ether:dichloromethane column chromatography (2:1 (v / v)). The final product, A4-2, was obtained in 7.4 g, yield: 57%, MS (m / z) (M+): 644.

[0037] A4-2 (7.4 g, 11.5 mmol), B4-2 (5.5 g, 11.5 mmol), and potassium carbonate (4.1 g, 30 mmol) were added to 300 mL of a toluene:water mixture of 4:1 (v / v). Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (1.2 g, 1 mmol) was introduced. The reaction mixture was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by petroleum ether:dichloromethane column chromatography (1:1 (v / v)). The final product was C4: 6.2 g, yield: 56%, MS (m / z) (M+): 962.

[0038] Synthesis Example 5

[0039] Using the same method as in Synthesis Example 1, A1 and B1 were replaced with A5 (5 g, 20 mmol) and B5 (19.2 g, 40 mmol) to finally obtain product C5: 13.6 g, yield: 77%, MS (m / z) (M+): 886.

[0040] Synthesis Example 6

[0041] Using the same method as in Synthesis Example 1, A1 and B1 were replaced with A6 (5 g, 20 mmol) and B6 (16.2 g, 40 mmol) to finally obtain product C6: 11.5 g, yield: 78%, MS (m / z) (M+): 734.

[0042] Synthesis Example 7

[0043] A7-1 (5.5 g, 20 mmol), B7-1 (8.1 g, 20 mmol), and potassium carbonate (4.1 g, 30 mmol) were added to 300 mL of a toluene:water mixture of 4:1 (v / v). Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (1.2 g, 1 mmol) was introduced. The reaction mixture was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by petroleum ether:dichloromethane column chromatography (2:1 (v / v). The final product was A7-2: 7.1 g, yield: 73%, MS (m / z) (M+): 486.

[0044] A7-2 (7.1 g, 14.6 mmol), B7-2 (5.9 g, 14.6 mmol), and potassium carbonate (4.1 g, 30 mmol) were added to 300 mL of a toluene:water mixture of 4:1 (v / v). Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (1.2 g, 1 mmol) was introduced. The reaction mixture was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by petroleum ether:dichloromethane column chromatography (1:1 (v / v)). The final product was C7: 8.1 g, yield: 73%, MS (m / z) (M+): 762.

[0045] Synthesis Example 8

[0046] Using the same method as in Synthesis Example 1, A1 and B1 were replaced with A8 (8 g, 20 mmol) and B8 (9.6 g, 40 mmol) to finally obtain product C8: 16.3 g, yield: 79%, MS (m / z) (M+): 1038.

[0047] Synthesis Example 9

[0048] Using the same method as in Synthesis Example 1, A9 (5 g, 20 mmol) and B9 (11.1 g, 40 mmol) were substituted for A1 and B1, and the final product C9 was obtained: 16.2 g, yield: 78%, MS (m / z) (M+): 1038.

[0049] Synthesis Example 10

[0050] Using the same method as in Synthesis Example 1, A10 (10.3 g, 20 mmol) and B10 (9.1 g, 40 mmol) were substituted for A1 and B1 to finally obtain product C10: 16.4 g, yield: 75%, MS (m / z) (M+): 1098.

[0051] Comparative Examples 1-4

[0052] The following are the compounds D1-D4 that were tested during the research process, and their specific structural formulas are as follows:

[0053] Material performance evaluation

[0054] Maximum negative electrostatic potential (ESP): When a material structure contains multiple electron-withdrawing substituents with strong electronegativity, it increases the overall electronegativity of the molecular structure, thereby improving the material's electron transport capability and its ability to coordinate with metal-doped materials. The electronegativity of a molecule can be evaluated using its maximum negative electrostatic potential (ESP). The larger the absolute value of ESP, the greater the electronegativity of the molecule and the better its nucleophilicity. Under B3LYP / 6-31G** conditions, ORCA was used to evaluate the ESP of the compounds in the synthetic examples and comparative examples.

[0055] Bond dissociation energy (BDE): The lifespan of an OLED is determined by the stability of the chemical bond energies of the material. Higher bond energies ensure continuous bond decomposition during thermal evaporation and OLED operation. The strength of chemical bonds can be measured by bond dissociation energy (BDE). A lower BDE indicates a weaker bond and a less stable compound. Using Orca software, the B3LYP / 6-31G(d) method was employed to calculate the dissociation energy of each chemical bond. Higher dissociation energies indicate greater stability of the bond within the structure. The stability of the materials was assessed by comparing the lowest dissociation energies of chemical bonds between different structures.

[0056] The results of the material performance evaluation are shown in Table 1.

[0057] Table 1

[0058] The calculation results show that the compounds in the synthesis examples, by using multiple electronegative groups, have significantly better overall maximum electrostatic potential (ESP) and dissociation energy (BDE) than the compounds in the comparative examples. This indicates that the compounds in the synthesis examples have greater electronegativity, better nucleophilicity, and more stable chemical bonds.

[0059] The reason for the above results is that, compared with Comparative Examples 2 and 3, the compounds provided by this invention significantly increase the absolute value of ESP by attaching highly electronegative phosphooxy substituents to phenanthroline. In particular, compared with Comparative Example 2, since the oxygen atom is in the second period, its electronegativity is significantly greater than that of the sulfur atom in the third period, thus increasing the absolute value of ESP. Compared with Comparative Example 1, the compounds of this invention, by using spacer groups, can avoid the decrease in BDE caused by excessive concentration of electron-withdrawing groups, thereby improving material stability. Compared with Comparative Example 4, the absolute value of ESP increases by using multiple phosphooxy substituents.

[0060] OLED manufacturing and characterization

[0061] Device Examples

[0062] The organic electroluminescent device provided by the present invention includes an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation region, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a capping layer, which are sequentially disposed on a substrate.

[0063] Furthermore, the first hole transport region includes a hole injection layer, a first hole transport layer, and a first electron blocking layer; the first electron transport region includes a first hole blocking layer and a first electron transport layer; the charge generation region includes an n-type charge generation layer and a p-type charge generation layer; the second hole transport region includes a second hole transport layer and a second electron blocking layer; the second electron transport region includes a second hole blocking layer, a second electron transport layer, and an electron injection layer.

[0064] Furthermore, the light-emitting layer is composed of a host material and doped materials, and the host material of the light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0065] The deuterated organic compounds described in this invention can be used in one or more layers of the above-mentioned organic electroluminescent devices, and are preferably used in the n-type charge generation layer material of the devices.

[0066] In this embodiment, the anode uses a commonly used anode material in the art, such as ITO, Ag, or their multilayer structures. The hole injection layer uses a commonly used hole injection material in the art, and is doped with F4TCNQ, HATCN, NDP-9, etc. The hole transport layer uses a commonly used hole transport material in the art. The light-emitting layer uses a commonly used light-emitting material and dopant material in the art, for example, it can be composed of a host material and a dopant material. The electron transport layer uses a commonly used electron transport material in the art. The electron injection layer uses a commonly used electron injection material in the art, such as Liq, LiF, Yb, etc. The n-type charge generation layer material uses the deuterated organic compound provided by this invention. The cathode uses a commonly used material in the art, such as metallic Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0067] The electrode fabrication method and the deposition method of each functional layer in this embodiment are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, and will not be described in detail here. Only some process details and testing methods in the fabrication process are supplemented as follows:

[0068] Device Example 1

[0069] The substrates used in this invention are all subjected to the following operations: the ITO substrate is patterned to give it a light-emitting area of ​​3mm × 3mm, then ultrasonicated with water / isopropanol, irradiated with UV / ozone, and then dried at 100°C. Afterwards, the ITO substrate is mounted on the substrate support of a vacuum deposition apparatus, and the pressure is adjusted to make the vacuum rate 1 × 10⁻⁶. -7 torr.

[0070] The following operations are then performed: First, a hole injection layer is formed on the ITO layer (anode) formed on the substrate by vacuum deposition of compound HTL-1 and compound p-dopant-1 (mass ratio of HTL-1 to p-dopant-1 is 97:3) with a thickness of 10 nm; second, a first hole transport layer is formed on the hole injection layer by vacuum deposition of compound HTL-1 with a thickness of 20 nm; third, a first electron blocking layer is formed on the first hole transport layer by vacuum deposition of compound EB-1 with a thickness of 5 nm; and fourth, a first electron blocking layer is formed on the first electron blocking layer by vacuum deposition of a mixture of compound BH-1 and compound BD-1 with a thickness of 20 nm. A light-emitting layer is formed, wherein BH-1 is used as the host and BD-1 is used as the dopant, with a host-to-dopant mass ratio of 98:2. Next, a first hole-blocking layer is formed on the first light-emitting layer by vacuum deposition of compound HB-1 with a thickness of 5 nm. Then, a first electron transport layer is formed on the first hole-blocking layer by vacuum deposition of compound ETL-1 and compound LiQ (ETL-1 to LiQ mass ratio of 1:1) with a thickness of 15 nm. Then, an n-type charge-generating layer is formed on the first electron transport layer by vacuum deposition of compound Cl and Yb (Cl and Yb mass ratio of 98:2) with a thickness of 15 nm. Finally, a compound HTL-1 and... A p-type charge generation layer is formed using compound p-dopant-1 (HTL-1 to p-dopant-1 mass ratio of 97:3). Then, a second hole transport layer is formed on the hole generation layer by vacuum deposition of compound HTL-1 with a thickness of 20 nm. Next, a second electron blocking layer is formed on the second hole transport layer by vacuum deposition of compound EB-1 with a thickness of 5 nm. Then, a second light-emitting layer is formed on the second electron blocking layer by vacuum deposition of a mixture of compounds BH-1 and BD-1 with a thickness of 20 nm, wherein BH-1 serves as the host and BD-1 as the dopant, with a host-to-dopant mass ratio of 98:2. Following this, the p-type charge generation layer is formed on the p-type charge generation layer by vacuum deposition of compound p-dopant-1 (HTL-1 to p-dopant-1 mass ratio of 97:3). On the second light-emitting layer, a second hole-blocking layer is formed by vacuum depositing compound HB-1 with a thickness of 5 nm. Then, on the second hole-blocking layer, a second electron transport layer is formed by vacuum depositing compound ETL-1 and compound LiQ (ETL-1 to LiQ mass ratio of 1:1) with a thickness of 15 nm. Then, on the second electron transport layer, an electron injection layer is formed by depositing Yb with a thickness of 1 nm. Then, on the electron injection layer, a cathode is formed by depositing Mg and Ag (Mg to Ag mass ratio of 1:9) with a thickness of 15 nm. Then, on the cathode, a capping layer is formed by depositing compound CPL-1 with a thickness of 50 nm, thus fabricating a stacked organic light-emitting device.

[0071] Apart from the materials used in this invention, the molecular structural formulas of the remaining layers of the device are as follows:

[0072] Device Examples 2-10

[0073] Organic electroluminescent devices were prepared by using the above method to synthesize the compounds in the synthesis examples, wherein C2 to C10 were used to replace C1 to prepare organic electroluminescent devices in Examples 2-10.

[0074] Device Comparison Examples 1-4

[0075] Organic electroluminescent devices were prepared by using the above method, wherein organic electroluminescent devices were prepared by replacing C1 with D1-D4 respectively.

[0076] The OLED devices described above were tested using standard methods. For this purpose, J = 10 mA / cm² was used. 2 The driving voltage, luminance, electroluminescent current efficiency (in cd / A), and external quantum efficiency (EQE, in percentage) of the organic electroluminescent device were determined at a given current density. The emission spectrum was calculated as a function of luminescence density from the current / voltage / luminescence density characteristic line (IVL characteristic line) exhibiting Lambertian emission characteristics. The lifetime LT was defined as the time after which, when operating at a constant current J, the luminance decreases from the initial luminance L0 to a specific proportion L1; J = 20 mA / cm². 2 The statement L1 = 90% refers to a value of 20 mA / cm². 2 When operating below the threshold, the luminous intensity decreases to 90% of its initial value L0 after time LT. Similarly, J = 20 mA / cm² 2 L1 = 95% refers to 20 mA / cm 2 When operating below the specified time, the luminous intensity drops to 95% of its initial value L0 after time LT.

[0077] Table 2 summarizes the data for various OLED devices. The parameters of the device examples and comparative examples are compared to demonstrate the performance data of the various OLED devices.

[0078] The testing instruments and methods used to perform performance testing on the OLED devices of the above embodiments and comparative examples are as follows:

[0079] Quantum efficiency (CE) (cd / A) and chromaticity coordinates (CIEy) were measured using a PhotoResearch PR-635 spectral scanner.

[0080] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter;

[0081] The blue index is obtained by dividing the quantum efficiency CE (cd / A) by the color coordinate (CIEy); lifetime testing: using the LT-96ch lifetime testing device.

[0082] Table 2 Device performance test results

[0083] The device results show that by designing the material structure and introducing phosphine-oxygen and phenanthroline structures, the introduction of highly electronegative atoms such as nitrogen, oxygen, and phosphine is enhanced, thereby increasing the maximum negative electrostatic potential of the molecule. This helps to effectively reduce the driving voltage of the fabricated organic electroluminescent device and improve its luminous efficiency. Simultaneously, improving the dissociation energy (BDE) can increase the lifetime of the organic electroluminescent device.

[0084] Compared to Comparative Example 1, the compounds of this invention improve material stability and significantly increase device lifetime by incorporating spacer groups. Simultaneously, compared to Comparative Examples 2, 3, and 4, the driving voltage of the device is significantly improved due to the increase in ESP and the improvement in electron transport capability. Because of the increased overall electron transport capability of the device, the carrier balance is improved, and the device embodiments using the materials described in this invention also have certain advantages in efficiency and lifetime.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. An organic compound having a plurality of heteroatoms, characterized in that, The general structural formula of the organic compound is shown in Formula I: R1-R4 each independently represent any one of hydrogen, deuterium, substituted or unsubstituted alkyl with C1-C30 carbon atoms, substituted or unsubstituted aryl with C6-C60 carbon atoms, substituted or unsubstituted fused-ring aryl with C6-C60 carbon atoms, or the group shown in Formula II, and at least two of R1-R4 represent the group shown in Formula II. L1-L4 each independently represent any one of the following: a single bond, a substituted or unsubstituted aryl group with 6-60 carbon atoms, a substituted or unsubstituted heteroaryl group with 5-60 carbon atoms, a substituted or unsubstituted fused-ring aryl group with 6-60 carbon atoms, or a substituted or unsubstituted heterofused-ring aryl group with 5-60 carbon atoms.

2. The organic compound according to claim 1, characterized in that, R1 and R2 each independently represent the group shown in Formula II, while R3 and R4 do not represent the group shown in Formula II.

3. The organic compound according to claim 1, characterized in that, R3 and R4 each independently represent the group shown in Formula II, while R1 and R2 do not represent the group shown in Formula II.

4. The organic compound according to claim 1, characterized in that, Each of L1-L4 independently represents a single bond. Any one of them.

5. The organic compound according to claim 1, characterized in that, Each of L1-L4 independently represents one of the following structures:

6. The organic compound according to claim 1, characterized in that, R1 and R2 represent the same group, R3 and R4 represent the same group, L1 and L2 represent the same group, and L3 and L4 represent the same group.

7. The organic compound according to claim 1, characterized in that, The organic compound is selected from one of the following structures:

8. The organic compound according to claim 1, characterized in that, The organic compound is selected from one of the following structures:

9. An organic electroluminescent device, characterized in that, The method comprises, sequentially disposed on a substrate, an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation region, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a capping layer; wherein the charge generation region comprises one or more organic compounds as described in any one of claims 1-8.

10. The organic electroluminescent device according to claim 9, characterized in that, The charge generation region includes an n-type charge generation layer and a p-type charge generation layer, wherein the n-type charge generation layer includes one or more organic compounds as described in any one of claims 1-8.

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