An organic compound, a composition containing the same, and an organic electroluminescent device

Abstract

The application provides an organic compound, a composition containing the same and an organic electroluminescent device. The structural general formula of the organic compound is shown in Formula I. The organic compound has good electron-donating ability and large steric hindrance, can effectively avoid the aggregation between molecules of a doping material, and avoid the problem of efficiency reduction of the organic electroluminescent device caused by concentration quenching. In addition, the composition containing the same can not only regulate the carrier transport balance and reduce the energy difference between the singlet state and the triplet state of the doping material through interaction, but also make the energy transmission in the light-emitting material more sufficient. When the composition provided by the application is applied to a light-emitting layer of a blue organic electroluminescent device, the light-emitting layer material can improve the light-emitting efficiency of the blue organic electroluminescent device, prolong the service life of the blue organic electroluminescent device, and overcome the defects of the prior art.

Description

Technical Field

[0001] This invention belongs to the field of OLED technology, and particularly relates to an organic compound, a composition containing the same, and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a display lighting technology that has gradually developed in recent years. Especially in the display industry, OLED displays have attracted widespread attention due to their advantages such as high response time, high contrast ratio, and flexibility. Currently, the pixel units of full-color OLED displays on the market are composed of red, green, and blue primary colors. According to the principle of the three primary colors, various colors can be generated by controlling the monochromatic gray levels of red, green, and blue in the sub-pixel units, thus displaying a color image. Among the three-color light-emitting devices, blue light materials have higher energy than red and green light materials. This energy can be transferred to lower-energy organic light-emitting materials such as green, yellow, and red light. Furthermore, according to the principle of the three primary colors, blue light emission is the foundation for achieving white and color displays. Therefore, blue light materials are a key research focus in the field of organic optoelectronic materials.

[0003] Currently, almost all blue organic light-emitting devices utilize a host-guest doping system for their luminescent layers, achieving electroluminescence by combining a host material with a guest dopant. Generally, the energy level of the host material's luminescence must be higher than that of the guest dopant. The luminescent layer, containing the host material, is the primary region for carrier recombination. Carriers recombine in the luminescent layer to generate excitons. The host material absorbs the energy of the excitons and transfers it to the guest dopant via Forster and Dexter energy transfer mechanisms, thus exciting the guest dopant and causing it to emit light.

[0004] However, existing blue organic light-emitting devices (OLEDs) primarily use single-host materials for their emitting layers. Single-host materials cannot effectively control the transport of holes and electrons; typically, holes transport faster than electrons, easily leading to carrier recombination imbalance. In severe cases, this can affect the exciton recombination region, thereby reducing the luminous efficiency of OLEDs. Furthermore, commonly used blue boron-nitrogen doped materials, due to their planar core structure, often experience dopant molecule aggregation during film formation, resulting in concentration quenching. This severely impacts the efficiency and lifetime of OLEDs. Therefore, there is an urgent need to develop a new emitting layer material for OLEDs. Summary of the Invention

[0005] In view of this, the present invention provides an organic compound, a composition comprising the same, and an organic electroluminescent device. The organic compound possesses good electron-donating ability and significant steric hindrance, effectively preventing aggregation between dopant molecules and avoiding the efficiency degradation of the organic electroluminescent device caused by concentration quenching. Furthermore, the composition comprising the same can, through interaction, not only regulate carrier transport balance and reduce the energy difference between the singlet and triplet states of the dopant material, but also enable more efficient energy transfer in the luminescent material. Applying the composition provided by the present invention to the luminescent layer of a blue organic electroluminescent device improves the luminous efficiency and extends the lifetime of the blue organic electroluminescent device, overcoming the shortcomings of the prior art.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In its first aspect, the present invention provides an organic compound, the general structural formula of which is shown in Formula I:

[0007]

[0008] The Ar1 is selected from aryl groups with 6 to 60 carbon atoms, substituted or unsubstituted, and fused-ring aryl groups with 10 to 60 carbon atoms, substituted or unsubstituted.

[0009] The L1 and L2 are independently selected from aryl groups with 6 to 30 carbon atoms that are single-bonded, substituted, or unsubstituted.

[0010] When any one of Ar1, L1, and L2 contains a substituent, the substituent of Ar1, L1, and L2 may be one or more, and each may be independently selected from deuterium, aryl with 6 to 30 carbon atoms, or fused-ring aryl with 10 to 30 carbon atoms.

[0011] According to the first aspect of the present invention, the compound containing a 5,5-spirosilicon fluorene structure has better electron-donating ability than compounds containing only carbon or arylsilanes. Furthermore, the 5,5-spirosilicon fluorene structure has greater steric hindrance, which can effectively prevent the aggregation between dopant molecules and avoid the efficiency reduction problem of organic electroluminescent devices caused by concentration quenching.

[0012] In conjunction with the first aspect, the Ar1 is selected from any one or any combination of two of phenyl, naphthyl, phenanthryl, pyrene, dimethylfluorenyl, and dimethylbenzofluorenyl.

[0013] In conjunction with the first aspect, the compound represented by Formula I is selected from any one of the following compounds:

[0014]

[0015]

[0016] A second aspect of the present invention provides a composition comprising one or more organic compounds as described in the first aspect, the composition further comprising one or more compounds of formula II and one or more compounds of formula III:

[0017]

[0018] The Ar2 is selected from aryl groups with 6 to 60 carbon atoms (substituted or unsubstituted) and fused-ring aryl groups with 10 to 60 carbon atoms (substituted or unsubstituted); more preferably, the Ar2 is selected from phenyl or naphthyl groups.

[0019] The R0 represents a single substituent to the most permissible substituent, each independently selected from hydrogen, deuterium, alkyl groups having 1 to 10 carbon atoms (substituted or unsubstituted), and alkenyl groups having 2 to 10 carbon atoms (substituted or unsubstituted). Two or more substituents can be bonded to each other through a linker or a single bond to form a benzene ring or a fused ring.

[0020] The L3 and L4 are independently selected from arylene groups with 6 to 30 carbon atoms that are single-bonded, substituted, or unsubstituted.

[0021] When any one of Ar2, R0, L3, and L4 contains a substituent, the substituent of Ar2, R0, L3, and L4 may be one or more, and each may be independently selected from deuterium, aryl with 6 to 30 carbon atoms, and fused-ring aryl with 10 to 30 carbon atoms.

[0022]

[0023] R1, R2, R3, and R4 each independently represent a monosubstituted group to the most permissible substituent, and are each independently selected from any one or any combination of hydrogen, deuterium, alkyl groups with 1 to 10 carbon atoms (substituted or unsubstituted), cycloalkyl groups with 3 to 30 carbon atoms (substituted or unsubstituted), aryl groups with 6 to 30 carbon atoms (substituted or unsubstituted), and aromatic amino groups with 12 to 30 carbon atoms (substituted or unsubstituted). Two or more substituents can be bonded to each other through a linking group or a single bond to form an aliphatic ring, aromatic ring, heteroaromatic ring, fused ring, or fused heterocyclic ring.

[0024] R5 represents a single substituent to the most permissible substituent, each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms. Two or more substituents can be bonded to each other by a linking group or a single bond to form an aliphatic ring, aromatic ring, heteroaromatic ring, fused ring or fused heterocyclic ring.

[0025] When any one of R1, R2, R3, R4, and R5 contains a substituent, the substituent of R1, R2, R3, R4, and R5 may be one or more, and may be independently selected from deuterium, alkyl groups having 1 to 10 carbon atoms, and cycloalkyl groups having 3 to 30 carbon atoms.

[0026] In conjunction with the second aspect, in the composition, the mass ratio of the compound shown in Formula I, the compound shown in Formula II, and the compound shown in Formula III is 49:49:2.

[0027] According to a second aspect of the present invention, a composition comprising the organic compound of Formula I as described in the first aspect, further comprising the compound of Formula II containing a furan structure and the compound of Formula III containing a steric hindrance and a thiophene structure, wherein the compound of Formula I contains a 5,5-spirosiliconfluorene structure and has electron-donating properties, which can adjust the electron cloud density on the anthracene ring and facilitate hole transport; the compound of Formula II contains a furan structure and has electron-withdrawing properties, which can adjust the electron cloud density on the anthracene ring and facilitate electron transport; the present invention can regulate the carrier transport balance through the interaction between the compound of Formula I and the compound of Formula II; the compound of Formula III contains a steric hindrance and a thiophene fragment, forming an asymmetric structure with a large dipole moment; there is a strong dipole-dipole interaction between the compound of Formula II and the compound of Formula III, which can enhance the FORSTER energy transfer process and facilitate reverse intersystem crossing.

[0028] In conjunction with the second aspect, the compound represented by Formula II is selected from any one of the structures represented by Formula II-1 to Formula II-2 below:

[0029]

[0030] In conjunction with the second aspect, the structures shown in formulas II-1 to II-2 are selected from any one of the structures shown in formulas II-11 to II-24 below:

[0031]

[0032]

[0033] In conjunction with the second aspect, the compound represented by Formula II is selected from any one of the following compounds:

[0034]

[0035]

[0036]

[0037]

[0038] In conjunction with the second aspect, the compound represented by Formula III is selected from any one of the structures represented by Formula III-1 to Formula III-2 below:

[0039]

[0040] In conjunction with the second aspect, the structure shown in Formula III-1 is selected from any one of the structures shown in Formulas III-11 to III-23 below:

[0041]

[0042]

[0043] In conjunction with the second aspect, the compound represented by Formula III is selected from any one of the following compounds:

[0044]

[0045]

[0046]

[0047]

[0048] A third aspect of the present invention provides a use of the composition described above as a light-emitting layer material.

[0049] A fourth aspect of the present invention provides an organic electroluminescent device, comprising a first electrode disposed sequentially on a substrate; a second electrode disposed opposite to the first electrode; and one or more organic functional layers disposed between the first electrode and the second electrode;

[0050] The organic functional layer includes a light-emitting layer; the light-emitting layer includes the composition described above.

[0051] In conjunction with the fourth aspect, the light-emitting layer includes a host material and a dopant material. The host material includes one or more compounds represented by chemical formula I and one or more compounds represented by chemical formula II. Specifically, the host material includes a first host material and a second host material. The first host material includes one or more compounds represented by formula I, and the second host material includes one or more compounds represented by formula II.

[0052] In conjunction with the fourth aspect, the doped material includes one or more compounds represented by chemical formula III.

[0053] The beneficial effects of this invention are as follows:

[0054] The first aspect of this invention provides a compound of Formula I containing a 5,5-spirosiliconfluorene structure. Compared with compounds containing only carbon or arylsilanes, the compound of Formula I containing a 5,5-spirosiliconfluorene structure provided by this invention has better electron-donating ability. Furthermore, the 5,5-spirosiliconfluorene structure has a large steric hindrance, which can effectively prevent the aggregation between dopant molecules and avoid the efficiency reduction problem of organic electroluminescent devices caused by concentration quenching.

[0055] A second aspect of this invention provides a composition comprising the compound of Formula I as described in the first aspect, a compound of Formula II containing a furan structure, and a compound of Formula III containing a steric hindrance and a thiophene structure. The compound of Formula I provided by this invention contains a 5,5-spirosilicon fluorene structure, exhibiting electron-donating properties that can adjust the electron cloud density on the anthracene ring, facilitating hole transport. The compound of Formula II provided by this invention contains a furan structure, exhibiting electron-withdrawing properties that can adjust the electron cloud density on the anthracene ring, facilitating electron transport. This invention, through the interaction between the compound of Formula I and the compound of Formula II, can regulate carrier transport balance. The compound of Formula III provided by this invention contains a steric hindrance and a thiophene fragment, forming an asymmetric structure with a large dipole moment. A strong dipole-dipole interaction exists between the compound of Formula II and the compound of Formula III provided by this invention, which can enhance the FORSTER energy transfer process and facilitate reverse intersystem crossing.

[0056] The third aspect of the present invention provides a novel use of the composition described in the second aspect as a light-emitting layer material, which improves the overall performance of the light-emitting layer material by utilizing the interaction between the compositions, thereby improving the overall performance of organic electroluminescent devices prepared using this light-emitting layer material as a raw material.

[0057] A fourth aspect of this invention provides an organic electroluminescent device, in which a compound of Formula I is used as a first host compound, a compound of Formula II as a second host compound, and a compound of Formula III as a dopant material in the light-emitting layer of the organic electroluminescent device. By using the compounds of Formula I and Formula II as dual host materials in the light-emitting layer of the organic electroluminescent device, this invention achieves a more balanced transport of holes and electrons in the light-emitting layer, resulting in the light-emitting recombination region being located within the light-emitting layer. This reduces the driving voltage of the organic electroluminescent device while further improving its efficiency. Furthermore, both the compounds of Formula I and Formula II provided by this invention are anthracene-based structures, and the conjugation degree of the introduced furan, spirosilylfluorene, and other organic fragments is less than that of the anthracene fragments, thus having a smaller impact on the light-emitting range of the host material. This invention utilizes the dipole-dipole relationship between the compounds of Formula II and Formula III. This invention reduces the energy difference between the singlet and triplet states of the doped material, enhances FORSTER energy transfer in the luminescent layer, and facilitates the reverse intersystem crossing process of the doped material, thereby improving the efficiency of organic light-emitting devices (OLEDs). The interaction between the compounds shown in Formula I, Formula II, and Formula III enables more complete energy transfer, effectively improving the efficiency of OLEDs. Furthermore, by rationally combining dual host materials and dopants, the interaction between the first host compound, the second host compound, and the dopant compound allows the OLED to exhibit significant advantages in high efficiency and long lifetime. Using the compounds shown in Formula I, Formula II, and Formula III as luminescent layer materials provided by this invention improves the luminous efficiency and extends the lifetime of blue OLEDs, overcoming the shortcomings of existing technologies. Attached image description:

[0058] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0059] Figure 1 A schematic diagram of the structure of an organic electroluminescent device containing the compounds and compositions of the present invention;

[0060] Figure description: 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-light-emitting auxiliary layer, 6-light-emitting layer, 7-electron transport layer, 8-electron injection layer, 9-cathode. Detailed Implementation

[0061] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. The embodiments and comparative examples in this specification are provided to provide a more complete explanation of the specification to those skilled in the art. Various modifications can be made based on the embodiments and comparative examples in this specification, and the scope of protection of the present invention should not be limited to the embodiments and comparative examples detailed below.

[0062] The organic compounds and compositions of the present invention are suitable for use in light-emitting elements, display panels, and electronic devices, particularly organic electroluminescent devices. The electronic devices of the present invention are devices comprising a layer of at least one organic compound, and may also comprise layers of inorganic materials or layers formed entirely of inorganic materials. Preferred electronic devices include organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic dye-sensitized solar cells (O-DSSCs), organic optical detectors, organic photosensors, organic field quenching devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), and organic plasma emitting devices. Organic electroluminescent devices (OLEDs) are particularly preferred.

[0063] To better understand the content of this invention, the organic compound, the preparation method of the 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.

[0064] Compound Synthesis Examples

[0065] Synthesis of intermediates of the first main compound

[0066]

[0067] At room temperature, K-1 (10.00 g, 30 mmol) and copper nitrate trihydrate (7.90 g, 32.5 mmol) were added to 200 mL of acetic anhydride, stirred for 10 min, heated to 40 °C, stirred for 4 h, cooled to room temperature, quenched with 1 L of water, and extracted three times with 500 mL of dichloromethane to separate the organic phase. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by recrystallization using dichloromethane or n-heptane to obtain product L-1: 8.48 g, yield: 75%, MS (m / z) (M+): 377.

[0068] At room temperature, L-1 (10.00 g, 27 mmol) and iron powder (10.0 g, 0.18 mol) were added to 250 mL of ethanol. The mixture was heated to 80 °C and refluxed. 40 mL of concentrated hydrochloric acid (1 mol / L) was slowly added dropwise, and the mixture was refluxed for 40 min. The mixture was then cooled to room temperature, filtered to remove excess iron filings, and the ethanol solvent was removed by rotary evaporation to obtain a crude product. The crude product was dissolved in 500 mL of water, and the pH was adjusted to neutral (pH = 7) by adding ammonia. The mixture was filtered to obtain a white precipitate, which was then purified by recrystallization from ethanol to obtain product M-1: 7.31 g, yield: 78%, MS (m / z) (M+): 347.

[0069] At room temperature, M-1 (20.00 g, 58 mmol) and 50 mL of concentrated hydrobromic acid (1.28 mol / L) were dissolved in 200 mL of water. The solution was cooled to 0 °C, and 50 mL of sodium nitrite aqueous solution (0.16 g / mL) was slowly added dropwise below 0 °C. The mixture was stirred at 0 °C for 30 min. Then, a concentrated hydrobromic acid solution (100 mL, 1.28 mol / L) containing cuprous bromide (10 g, 0.07 mol) at 0 °C was added. The solution was heated to 100 °C and stirred for 30 min. The solution was then cooled to room temperature, and the mixture was filtered to obtain a white precipitate. The white precipitate was washed with saturated sodium bicarbonate solution and water to obtain a crude product. The crude product was purified by recrystallization from dichloromethane or n-heptane to obtain product N-1: 11.92 g, yield: 50%, MS (m / z) (M+): 411.

[0070] Under nitrogen protection, N-1 (10.00 g, 25 mmol) was dissolved in tetrahydrofuran (100 mL), cooled to -78 °C, and 48 mL of n-butyllithium in hexane (1.6 mol / L) was slowly added dropwise while maintaining the temperature at -78 °C. Then, triisopropyl borate (7.05 g, 37.5 mmol) was added dropwise. The reaction system was heated to -30 °C, 30 mL of water was added, and the temperature was raised to 0 °C. The pH was adjusted to 1-2 by adding concentrated hydrochloric acid (1 mol / L), and the temperature was raised to 20 °C and stirred for 2 h. The temperature was then lowered to room temperature, and the reaction solution was separated. Ethyl acetate was added for extraction to obtain the organic phase. The organic phase was washed with saturated brine until neutral, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by recrystallization from ethyl acetate or n-heptane to obtain product B-11: 6.11 g, yield: 65%, MS (m / z) (M+): 376.

[0071] After obtaining B-11 through the above process, other first host compound intermediates can be prepared using a method similar to that of B-11.

[0072] Example 1

[0073] This embodiment provides a first host compound C-11, the synthetic route of which is as follows:

[0074]

[0075] A-11 (3.33 g, 10 mmol) and B-11 (3.76 g, 10 mmol) were added to a mixture of toluene and water (80 mL of toluene and 20 mL of water). Under nitrogen protection, potassium carbonate (1.65 g, 10 mmol) and 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride (73 mg, 0.1 mmol) were added to the system. The reaction system was heated to 85 °C and refluxed for 16 hours. After cooling to room temperature, the mixture was quenched with ice water and separated to obtain the organic phase. The organic phase was filtered and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified to finally obtain product C-11: 4.50 g (yield: 77%), MS (m / z) (M+): 585.

[0076] Example 2

[0077] This embodiment provides a first host compound C-12, the synthetic route of which is as follows:

[0078]

[0079] Using the same method as in Example 1, A-12 (3.83 g, 10 mmol) was replaced with A-11, and B-12 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-12: 4.76 g (yield: 75%), MS (m / z) (M+): 635.

[0080] Example 3

[0081] This embodiment provides a first host compound C-13, the synthetic route of which is as follows:

[0082]

[0083] Using the same method as in Example 1, A-11 was replaced with A-13 (3.83 g, 10 mmol), and B-11 was replaced with B-13 (3.76 g, 10 mmol), finally yielding product C-13: 4.70 g (yield: 74%), MS (m / z) (M+): 635.

[0084] Example 4

[0085] This embodiment provides a first host compound C-14, the synthetic route of which is as follows:

[0086]

[0087] Using the same method as in Example 1, A-14 (4.09 g, 10 mmol) was replaced with A-11, and B-14 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-14: 5.35 g (yield: 81%), MS (m / z) (M+): 661.

[0088] Example 5

[0089] This embodiment provides a first host compound C-15, the synthetic route of which is as follows:

[0090]

[0091] Using the same method as in Example 1, A-15 (4.59 g, 10 mmol) was replaced with A-11, and B-15 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-15: 5.19 g (yield: 73%), MS (m / z) (M+): 711.

[0092] Example 6

[0093] This embodiment provides a first host compound C-16, the synthetic route of which is as follows:

[0094]

[0095] Using the same method as in Example 1, A-16 (4.09 g, 10 mmol) was replaced with A-11, and B-16 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-16: 5.35 g (yield: 81%), MS (m / z) (M+): 661.

[0096] Example 7

[0097] This embodiment provides a first host compound C-17, the synthetic route of which is as follows:

[0098]

[0099] Using the same method as in Example 1, A-17 (4.59 g, 10 mmol) was replaced with A-11, and B-17 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-17: 5.55 g (yield: 78%), MS (m / z) (M+): 711.

[0100] Example 8

[0101] This embodiment provides a first host compound C-18, the synthetic route of which is as follows:

[0102]

[0103] Using the same method as in Example 1, A-11 was replaced with A-18 (4.49 g, 10 mmol), and B-11 was replaced with B-18 (3.76 g, 10 mmol), finally yielding product C-18: 5.54 g (yield: 79%), MS (m / z) (M+): 701.

[0104] Example 9

[0105] This embodiment provides a first host compound C-19, the synthetic route of which is as follows:

[0106]

[0107] Using the same method as in Example 1, A-19 (5.25 g, 10 mmol) was replaced with A-11, and B-19 (3.76 g, 10 mmol) was replaced with B-11, finally yielding product C-19: 6.29 g (yield: 81%), MS (m / z) (M+): 777.

[0108] Example 10

[0109] This embodiment provides a second host compound C-2, the synthetic route of which is as follows:

[0110]

[0111] A-2 (4.99 g, 10 mmol) and B-2 (1.72 g, 10 mmol) were added to a mixture of toluene and water (80 mL and 20 mL of toluene and water, respectively). Under nitrogen protection, potassium carbonate (1.65 g, 10 mmol) was added to the system to introduce 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride (73 mg, 0.1 mmol). The reaction system was then heated to reflux and maintained for 16 hours. After cooling to room temperature, the reaction was quenched with ice water and separated to obtain the organic phase. The organic phase was filtered and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to finally obtain product C-2: 4.21 g (yield: 77%), MS (m / z) (M+): 547.

[0112] Example 11

[0113] This embodiment provides a second host compound C-3, the synthetic route of which is as follows:

[0114]

[0115] Using the same method as in Example 10, except that A-3 (4.99 g, 10 mmol) replaced A-2 and B-3 (1.72 g, 10 mmol) replaced B-2, the final product C-3 was obtained: 4.10 g (yield: 75%), MS (m / z) (M+): 547.

[0116] Example 12

[0117] This embodiment provides a second host compound C-4, the synthetic route of which is as follows:

[0118]

[0119] Using the same method as in Example 10, except that A-4 (4.99 g, 10 mmol) replaced A-2 and B-4 (1.72 g, 10 mmol) replaced B-2, the final product C-4 was obtained: 4.10 g (yield: 75%), MS (m / z) (M+): 547.

[0120] Example 13

[0121] This embodiment provides a second host compound C-5, the synthetic route of which is as follows:

[0122]

[0123] Using the same method as in Example 10, except that A-5 (4.99 g, 10 mmol) replaced A-2 and B-5 (1.22 g, 10 mmol) replaced B-2, the final product C-5 was obtained: 3.63 g (yield: 73%), MS (m / z) (M+): 497.

[0124] Example 14

[0125] This embodiment provides a second host compound, C-6, whose synthetic route is as follows:

[0126]

[0127] Using the same method as in Example 10, except that A-6 (4.99 g, 10 mmol) replaced A-2 and B-6 (1.22 g, 10 mmol) replaced B-2, the final product C-6 was obtained: 3.68 g (yield: 74%), MS (m / z) (M+): 497.

[0128] Example 15

[0129] This embodiment provides a second host compound C-7, the synthetic route of which is as follows:

[0130]

[0131] Using the same method as in Example 10, except that A-7 (4.99 g, 10 mmol) replaced A-2 and B-7 (1.72 g, 10 mmol) replaced B-2, the final product C-7 was obtained: 4.27 g (yield: 78%), MS (m / z) (M+): 547.

[0132] Example 16

[0133] This embodiment provides a second host compound C-8, the synthetic route of which is as follows:

[0134]

[0135] Using the same method as in Example 10, except that A-8 (4.23 g, 10 mmol) replaced A-2 and B-8 (1.72 g, 10 mmol) replaced B-2, the final product C-8 was obtained: 3.96 g (yield: 84%), MS (m / z) (M+): 471.

[0136] Example 17

[0137] This embodiment provides a second host compound C-9, the synthetic route of which is as follows:

[0138]

[0139] Using the same method as in Example 10, except that A-9 (4.73 g, 10 mmol) replaced A-2 and B-9 (1.72 g, 10 mmol) replaced B-2, the final product C-9 was obtained: 4.32 g (yield: 83%), MS (m / z) (M+): 521.

[0140] Example 18

[0141] This embodiment provides a second host compound C-10, the synthetic route of which is as follows:

[0142]

[0143] Using the same method as in Example 10, except that A-10 (4.23 g, 10 mmol) was replaced with A-2 and B-10 (1.72 g, 10 mmol) was replaced with B-2, the final product C-10 was obtained: 4.00 g (yield: 85%), MS (m / z) (M+): 471.

[0144] Synthesis of doped material intermediates

[0145]

[0146] The general formula for intermediate synthesis is shown above. The target intermediate can be obtained through a two-step Buchwald-Hartwig coupling synthesis method.

[0147] Specific examples are as follows:

[0148]

[0149] F-1 (8.75 g, 0.05 mol), G-1 (12.11 g, 0.045 mol), and sodium tert-butoxide (5.28 g, 0.055 mol) were added to toluene (200 mL). Then, under nitrogen protection, palladium dibenzylacetone (0.46 g, 0.5 mmol) and SPhos (0.41 g, 1 mmol) were introduced. The reaction system was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product Sub1: 11.47 g, yield: 70%, MS (m / z) (M+): 364.

[0150]

[0151] H-1 (16.9 g, 0.05 mol), J-1 (15.26 g, 0.045 mol), and sodium tert-butoxide (5.28 g, 0.055 mol) were added to toluene (500 mL). Under nitrogen protection, palladium dibenzylacetone (0.46 g, 0.5 mmol) and SPhos (0.41 g, 1 mmol) were introduced. The reaction system was then heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product Sub4: 20.01 g, yield: 81%, MS (m / z) (M+): 549.

[0152]

[0153] Sub1 (3.64 g; 10 mmol), Sub2 (2.63 g; 9 mmol), and sodium tert-butoxide (1.05 g, 11 mmol) were added to toluene (50 ml). Under nitrogen protection, bis(dibenzylacetone)palladium (274.28 mg, 0.30 mmol) and tri-tert-butylphosphine (121.2 mg, 0.6 mmol) were introduced. The reaction system was then heated to reflux and maintained for 10 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to finally obtain product Sub3: 4.14 g (yield: 80%), MS (m / z) (M+): 575.

[0154] Sub3 (5.75 g; 10 mmol), Sub4 (5.49 g; 10 mmol), and sodium tert-butoxide (1.05 g, 11 mmol) were added to toluene (100 ml). Under nitrogen protection, bis(dibenzylacetone)palladium (274.28 mg, 0.30 mmol) and tritert-butylphosphine (121.2 mg, 0.6 mmol) were introduced. The reaction system was then heated to reflux and maintained for 10 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to finally obtain product D-1: 6.77 g (yield: 65%), MS (m / z) (M+): 1042.

[0155] After obtaining D-1 through the above process, other doped material intermediates can be prepared using a method similar to that of D-1.

[0156] Example 19

[0157] This embodiment provides a compound E-1 as a dopant material. The synthetic route of this compound is as follows:

[0158]

[0159] D-1 (10.42 g; 10 mmol) was added to tert-butylbenzene (125 ml), and then cooled to 0 °C under nitrogen protection. 12.4 ml (21 mmol) of 1.7 M tert-butyllithium pentane solution was added, and the mixture was heated to 60 °C and stirred for 2 hours. Then, the mixture was cooled to 0 °C, and 2.0 ml (21 mmol) of boron tribromide was added and stirred for 0.5 h. At 0 °C, 3.65 ml (21 mmol) of N,N-diisopropylethylamine was added, and the mixture was heated to 60 °C and stirred for 2 h. After cooling to room temperature, the reaction was quenched with ice water and separated to obtain the organic phase. The organic phase was filtered and dehydrated with anhydrous magnesium sulfate. After removing the organic solvent by rotary evaporation, the crude product was obtained. The crude product was purified by recrystallization from dichloromethane and n-heptane to finally obtain product E-1: 1.46 g (yield: 15%), MS (m / z) (M+): 971.

[0160] Example 20

[0161] This embodiment provides a compound E-2 as a dopant material, and the synthetic route of this compound is as follows:

[0162]

[0163] Using the same method as in Example 19, except that D-2 (10.52 g; 10 mmol) was replaced with D-1, the final product E-2 was obtained: 1.18 g (yield: 12%), MS (m / z) (M+): 981.

[0164] Example 21

[0165] This embodiment provides a compound E-3 as a dopant material, and the synthetic route of this compound is as follows:

[0166]

[0167] Using the same method as in Example 19, except that D-3 (10.7 g; 10 mmol) was replaced with D-1, the final product E-3 was obtained: 1 g (yield: 10%), MS (m / z) (M+): 999.

[0168] Example 22

[0169] This embodiment provides a compound E-4 as a dopant material, and the synthetic route of this compound is as follows:

[0170]

[0171] Using the same method as in Example 19, except that D-4 (10.7 g; 10 mmol) was replaced with D-1, the final product E-4 was obtained: 1.4 g (yield: 14%), MS (m / z) (M+): 999.

[0172] Example 23

[0173] This embodiment provides a compound E-5 as a dopant material, and the synthetic route of this compound is as follows:

[0174]

[0175] Using the same method as in Example 19, except that D-5 (11.09 g; 10 mmol) was replaced with D-1, the final product E-5 was obtained: 1.35 g (yield: 13%), MS (m / z) (M+): 1037.

[0176] Example 24

[0177] This embodiment provides a compound E-6 as a dopant material, and the synthetic route of this compound is as follows:

[0178]

[0179] Using the same method as in Example 19, except that D-6 (10.82 g; 10 mmol) was replaced with D-1, the final product E-6 was obtained: 0.81 g (yield: 8%), MS (m / z) (M+): 1011.

[0180] Example 25

[0181] This embodiment provides a compound E-7 as a dopant material, and the synthetic route of this compound is as follows:

[0182]

[0183] Using the same method as in Example 19, except that D-7 (10.3 g; 10 mmol) was replaced with D-1, the final product E-7 was obtained: 1.25 g (yield: 13%), MS (m / z) (M+): 959.

[0184] Example 26

[0185] This embodiment provides a compound E-8 as a dopant material, and the synthetic route of this compound is as follows:

[0186]

[0187] Using the same method as in Example 19, except that D-1 was replaced with D-8 (9.6 g; 10 mmol), the final product E-8 was obtained: 0.71 g (yield: 8%), MS (m / z) (M+): 889.

[0188] Example 27

[0189] This embodiment provides a compound E-9 as a dopant material, and the synthetic route of this compound is as follows:

[0190]

[0191] Using the same method as in Example 19, except that D-9 (11.33 g; 10 mmol) was replaced with D-1, the final product E-9 was obtained: 0.95 g (yield: 9%), MS (m / z) (M+): 1061.

[0192] Example 28

[0193] This embodiment provides a compound E-10 as a dopant material, and the synthetic route of this compound is as follows:

[0194]

[0195] Using the same method as in Example 19, except that D-1 was replaced with D-1 (12.03 g; 10 mmol), the final product E-10 was obtained: 1.25 g (yield: 11%), MS (m / z) (M+): 1132.

[0196] Composition Examples

[0197] Examples 29 to 168

[0198] This embodiment provides compositions Z1 to Z140, which are obtained by combining a first main compound, a second main compound, and a dopant material according to Table 1 and mixing them evenly. The mass ratio of the first main compound, the second main compound, and the dopant material is 49:49:2.

[0199] Table 1

[0200]

[0201]

[0202]

[0203] Comparative Example 1

[0204] This comparative example provides a compound BH-1 that was tested during the research process, and its specific structural formula is as follows:

[0205]

[0206] Comparative Example 2

[0207] This comparative example provides a compound BH-2 that was tested during the research process, and its specific structural formula is as follows:

[0208]

[0209] Comparative Example 3

[0210] This comparative example provides a compound BD-1 that was tested during the research process, and its specific structural formula is as follows:

[0211]

[0212] Comparative Example 4

[0213] This comparative example provides a compound BD-2 that was tested during the research process, and its specific structural formula is as follows:

[0214]

[0215] Comparative Examples of Compositions

[0216] Comparative examples 5 to 10

[0217] This comparative example provides compositions DB1 to DB6 that were tested during the study. The first host compound, the second host compound, and the dopant were combined according to Table 2 and mixed evenly to obtain compositions DB1 to DB6. The mass ratio of the first host compound, the second host compound, and the dopant in DB1 to DB4 was 49:49:2, and the mass ratio of the host compound to the dopant in DB5 to DB6 was 98:2.

[0218] Table 2

[0219] 5 DB1 BD-1 C-17 C-5 6 DB2 BD-2 C-17 C-5 7 DB3 E-1 C-17 BH-1 8 DB4 E-1 BH-2 C-5 9 DB5 E-1 -- C-5 10 DB6 E-1 C-17 --

[0220] Composition performance evaluation

[0221] To demonstrate the unique advantages of the composition provided by this invention, the following tests were conducted:

[0222] 1. To illustrate the unique advantages of the composition materials provided by this invention in the interaction between the host material and the dopant material, the molecular structure characteristics of the first host compound, the second host compound, and the dopant material in the compositions provided in Examples 29 to 168 and Comparative Examples 5 to 10 were calculated. Using Gaussian 09W software, based on density functional theory (DFT) calculations (basis set level set to: b3lyp / 6-31g(d), charge number 0), the molecular structure was geometrically optimized to obtain the dipole moments of the first host compound, the second host compound, and the dopant material in the ground state. Since the dipole moment of the second host compound is much larger than that of the first host compound, the second host compound is the main factor inducing the compound structure of the dopant material in the ground state. Therefore, the ratio of their dipole moments, X = D, was calculated. BD / D BH2 As a parameter measuring the strength of the interaction between the host material and the doped material in the ground state, the larger this value, the smaller the dipole moment of the host compound and the weaker the interaction when the dipole moment of the doped material is constant. Based on this, the recombination energies of the first host compound and the second host compound in the compositions provided in Examples 29 to 168 and Comparative Examples 5 to 10 under positive and negative charges were further calculated. Generally, the smaller the recombination energy, the faster the mobility. The ratio of the hole recombination energy of the first host compound to the electron recombination energy of the second host compound obtained by calculation, i.e., the Y value, is used as a parameter to measure the equilibrium carriers of the host material, Y = λh. BH1 / λe BH2 If the Y value is less than 1, the carrier transport is biased towards holes; if the Y value is greater than 1, the carrier transport is biased towards electrons. The closer the Y value is to 1, the more balanced the carrier transport is.

[0223] 2. The energy transfer between the host material and the dopant material is related to the degree of overlap between the emission spectrum of the host material and the absorption spectrum of the dopant material. The larger the overlap integral, the greater the energy transfer between the host material and the dopant material. To illustrate that the composition provided by this invention has a high energy transfer between the host material and the dopant material, the fluorescence emission spectrum of the host material and the ultraviolet-visible absorption spectrum of the dopant material in the compositions provided in Examples 29 to 168 and Comparative Examples 5 to 10 were tested, and their overlap integrals were calculated after normalizing the spectra. The ultraviolet-visible absorption spectrum of the dopant material was measured using a PerkinElmer LAMBDA35 ultraviolet-visible spectrophotometer, and the fluorescence spectrum of the host material was measured using a Fluoro Max (HORIBA) fluorophotometer. Specifically, the first host compound, the second host compound, and the dopant material in the compositions provided in Examples 29 to 168 and Comparative Examples 5 to 10 were respectively prepared to a molar concentration of 5*10⁻⁶. -5The above spectral tests were performed using a mol / L toluene solution. The test results were processed using Origin software. The integral area of ​​the overlap between the compound acting as a dopant and the second host compound was denoted as S1, and the integral area of ​​the overlap between the compound acting as a dopant and the first host compound was denoted as S2. The calculated X values, Y values, S1, and S2 results are shown in Table 3.

[0224] Table 3. Results of composition performance tests

[0225]

[0226]

[0227]

[0228]

[0229] As shown in Table 3, the X value of the composition provided by this invention is relatively low. Replacing any one of the dopant, the first host compound, or the second host compound in the composition Z15 provided by this invention with other commonly used compounds of the same type, or removing them altogether, significantly increases the X value. This indicates a strong interaction between the first host compound, the second host compound, and the dopant material in the composition provided by this invention. The second host compound provided by this invention contains a benzofuran structure, and the compound used as the dopant material contains a thiophene structure. Through the interaction of these two structures, the composition provided by this invention can enhance the dipole-dipole interaction between the host material and the dopant material, thereby enhancing the luminescent material. FORSTER energy transfer of the material; as shown in Table 3, the Y value of the composition provided by the present invention is closer to 1. Replacing either the first or second host compound in the composition Z15 provided by the present invention with other commonly used compounds of the same type or removing them will cause the Y value to deviate significantly from 1, indicating that the transfer of holes and electrons between the first and second host compounds in the composition provided by the present invention is more balanced; as shown in Table 3, compared with the comparative composition, the integral area of ​​the overlap between the emission spectrum of the host material and the absorption spectrum of the dopant material in the composition provided by the present invention is larger, indicating that the energy transfer between the host material and the dopant material in the composition provided by the present invention is more sufficient.

[0230] Device Example 1

[0231] This embodiment provides a blue organic light-emitting diode (OLED), the fabrication method of which is as follows: First, a hole injection layer is formed on an ITO layer (anode) formed on a substrate by vacuum deposition of HTL and p-dopant (HTL to p-dopant mass ratio of 97:3) with a thickness of 10 nm; second, a hole transport layer is formed on the hole injection layer by vacuum deposition of HTL with a thickness of 120 nm; and third, a B2O3 layer is formed on the hole transport layer by vacuum deposition with a thickness of 5 nm. A light-emitting auxiliary layer is formed by depositing a prime material. Then, on the aforementioned light-emitting auxiliary layer, a mixture of host material and dopant material is vacuum-deposited to a thickness of 20 nm to form a light-emitting layer, wherein C-11 is the first host compound, C-2 is the second host compound, and E-1 is the dopant material, with a mass ratio of the first host compound, the second host compound, and the dopant material of 49:49:2. Next, on the aforementioned light-emitting layer, a hole-blocking layer (HBL) is vacuum-deposited to a thickness of 5 nm. An electron transport layer (ET and Liq, with a mass ratio of 1:1) is vacuum-deposited to a thickness of 30 nm. Then, an electron injection layer (LiF) is deposited to a thickness of 0.2 nm on the aforementioned electron transport layer. Finally, an electron cathode (Al) is deposited to a thickness of 150 nm on the aforementioned electron injection layer, thus fabricating a blue organic light-emitting device.

[0232] Apart from the host material and doped material of the light-emitting layer, the molecular structure formulas of the other layers are as follows:

[0233]

[0234] The electrode preparation 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.

[0235] Device Example 2-140

[0236] The method is the same as in Device Example 1, except that the light-emitting layer material is replaced with the compositions of Examples 30 to 168 respectively. The main material and doping material in the device examples are shown in Table 4.

[0237] Table 4 Comparison of main materials and doped materials in device embodiments

[0238]

[0239]

[0240]

[0241]

[0242] Device Comparison Examples 1-6

[0243] The method is the same as in Device Example 1, except that the light-emitting layer material is replaced with the composition of Comparative Examples 5 to 10. The main material and doped material in the device examples are shown in Table 5.

[0244] Table 5 Comparison of main materials and doped materials in the device comparison examples.

[0245] Device Comparison Example 1 BD-1 C-17 C-5 Device Comparison Example 2 BD-2 C-17 C-5 Device Comparison Example 3 E-1 C-17 BH-1 Device Comparison Example 4 E-1 BH-2 C-5 Device Comparison Example 5 E-1 -- C-5 Device Comparison Example 6 E-1 C-17 --

[0246] Example of device performance

[0247] The organic electroluminescent devices provided in Device Examples 1-140 and Comparative Examples 1-6 were tested using standard methods. For this purpose, at J = 20 mA / cm²... 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 as a function of luminescence density from the current / voltage / luminescence density characteristic line (IVL characteristic line) exhibiting Lambertian emission characteristics, and the emission spectrum. The lifetime LT was defined as the time after which, when operating at a constant current J, the luminance decreased from the initial luminance L0 to a specific proportion L1; J = 50 mA / cm². 2 The statement L1 = 90% refers to a value of 50 mA / cm. 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 = 80% means that at 20 mA / cm 2 When operating below the threshold, the luminous intensity drops to 80% of its initial value L0 after time LT.

[0248] The testing instruments and methods used to perform performance testing on the above-mentioned OLED devices are as follows:

[0249] Brightness was tested using a PhotoResearch PR-635 spectral scanner;

[0250] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter;

[0251] Life test: The LT-96ch life test device was used.

[0252] The performance test results of the above devices are listed in Table 6.

[0253] Table 6 Performance test results of blue light devices

[0254]

[0255]

[0256]

[0257]

[0258] As shown in Table 6 above, the device performance test results indicate that, compared with the comparative device, the organic electroluminescent device provided by this invention exhibits significantly improved efficiency and lifetime. Replacing any one of the dopant, the first host compound, or the second host compound in Device Example 15 of this invention with other commonly used compounds of the same type, or removing them altogether, significantly reduces both efficiency and lifetime. This is because the first host compound in the composition provided by this invention has a large steric hindrance between it and the compound used as a dopant, effectively preventing the aggregation of the compound used as a dopant and avoiding the efficiency decrease caused by concentration quenching, thereby extending the lifetime of the organic electroluminescent device. Furthermore, the second host compound in the composition provided by this invention has a strong dipole-dipole interaction with the compound used as a dopant. The composition of this invention helps to reduce the energy difference between the singlet and triplet states of the dopant material, enhances the FORSTER energy transfer in the light-emitting layer, and facilitates the reverse intersystem crossing process of the dopant material, thereby improving the efficiency of organic light-emitting devices (OLEDs). The composition provides a more balanced transport of holes and electrons between the first and second host compounds, ensuring the light-emitting recombination region is located in the light-emitting layer. This reduces the driving voltage of the OLED while further improving its efficiency. The composition also features large overlap areas between the first host compound and the dopant compound, as well as between the second host compound and the dopant compound, ensuring sufficient energy transfer between the host and dopant materials and effectively improving the efficiency of the OLED. By rationally combining the dual host materials and dopant materials, this invention enables the OLED to exhibit significant advantages of high efficiency and long lifetime through the interaction of the first host compound, the second host compound, and the dopant compound. Using the composition of this invention as the light-emitting layer material can improve the luminous efficiency and extend the lifetime of blue OLEDs, overcoming the shortcomings of existing technologies.

[0259] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A composition, characterized in that, The composition comprises one or more compounds of Formula I: The compound represented by Formula I is selected from any one of the following: ； The composition further includes one or more compounds of formula II and one or more compounds of formula III: The compound represented by Formula II is selected from any one of the following compounds: ； Ⅲ； R1, R2, R3, and R4 each independently represent a monosubstituted group to the most permissible substituent, and are each independently selected from any one or any combination of hydrogen, deuterium, alkyl groups with 1 to 10 carbon atoms (substituted or unsubstituted), cycloalkyl groups with 3 to 30 carbon atoms (substituted or unsubstituted), aryl groups with 6 to 30 carbon atoms (substituted or unsubstituted), and aromatic amino groups with 12 to 30 carbon atoms (substituted or unsubstituted). Two or more substituents can be bonded to each other through a linking group or a single bond to form an aliphatic ring, aromatic ring, heteroaromatic ring, fused ring, or fused heterocyclic ring. R5 represents a single substituent to the most permissible substituent, each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms. Two or more substituents can be bonded to each other by a linking group or a single bond to form an aliphatic ring, aromatic ring, heteroaromatic ring, fused ring or fused heterocyclic ring. When any one of R1, R2, R3, R4, and R5 contains a substituent, the substituent of R1, R2, R3, R4, and R5 may be one or more, and may be independently selected from deuterium, alkyl groups having 1 to 10 carbon atoms, and cycloalkyl groups having 3 to 30 carbon atoms.

2. The composition according to claim 1, characterized in that, The compound represented by Formula III is selected from any one of the structures shown in Formula III-1 to Formula III-2 below: Ⅲ-1、 Ⅲ-2。 3. The composition according to claim 1, characterized in that, The compound represented by Formula III is selected from any one of the following compounds: 。 4. Use of the composition according to any one of claims 1 to 3 as a light-emitting layer material.

5. An organic electroluminescent device, characterized in that, Includes a first electrode sequentially disposed on a substrate; configured to be connected with the... The second electrode opposite the first electrode; and one or more organic functional layers disposed between the first electrode and the second electrode; The organic functional layer includes a light-emitting layer, which comprises the composition according to any one of claims 1 to 3.

6. The organic electroluminescent device according to claim 5, characterized in that, The light-emitting layer includes a host material and a dopant material. The host material includes one or more compounds represented by chemical formula I and one or more compounds represented by chemical formula II. The dopant material includes one or more compounds represented by chemical formula III.

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