WO2022183900A1 - Organic light-emitting device having thermally activated delayed fluorescent material as light-emitting layer material - Google Patents

Abstract

Disclosed in the present invention is an organic light-emitting device having a thermally activated delayed fluorescent material as a light-emitting layer material. The thermally activated delayed fluorescent material comprises one of a thermally activated delayed red light fluorescent material, a thermally activated delayed blue light fluorescent material, or a seven-membered ring thermally activated delayed fluorescent material. The general formula of the thermally activated delayed red light fluorescent material is: aa; the general formula of the thermally activated delayed blue light fluorescent material is: bb; the general formula of the seven-membered ring thermally activated delayed fluorescent material is: cc.

Description

An organic light-emitting device using thermally activated delayed fluorescent material as light-emitting layer material technical field

The invention relates to the technical field of organic optoelectronic materials, in particular to an organic light-emitting device using a thermally activated delayed fluorescent material as a material for a light-emitting layer.

Background technique

Organic Light Emitting Diodes (OLED), referred to as OLED, is a type of device that uses organic materials to generate light under the action of an electric field and is excited by current or voltage, mostly using a sandwich structure. OLED has attracted much attention in the field of new display and lighting technology due to its incomparable advantages such as saturated color quality, low power consumption, fast response speed, and large area preparation. At present, OLED is mainly used in the display screen field of computers and mobile phones, as well as in the field of home, shopping mall and vehicle lighting, and will expand to the application field of large-size display products in the future.

Light-emitting material is the core material of OLED. At present, three generations of light-emitting materials have been developed, namely fluorescent material, phosphorescent material and thermally activated delayed fluorescent material (Thermally Activated Delayed Fluorescence, TADF). Among them, fluorescent materials have low efficiency, phosphorescent materials need to use noble metals and blue phosphorescent materials have poor stability, while TADF materials can achieve 100% internal quantum efficiency and low cost, so they are currently the most commercially promising research hotspots.

The currently commonly used TADF material has a large fluorescence emission spectrum Full Width at Half Maximum (FWHM) value, resulting in low color purity and poor monochromaticity of the device. Although multiple resonance-induced thermally activated delayed fluorescence (MR-TADF) materials can effectively solve this problem: through the intramolecular resonance effect, HOMO/LUMO separation can be achieved while minimizing long-range charge transfer states, enabling high-efficiency and narrow-band luminescence. However, the luminescent color of MR-TADF materials is difficult to control and is accompanied by a severe roll-off of device efficiency, which largely limits the further application of MR-TADF materials in the field of full-color display and lighting.

Therefore, the existing technology still needs to be improved and developed.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide an organic light-emitting device using a thermally activated delayed fluorescent material as a material for the light-emitting layer, aiming to solve the problems of low color purity and low luminous efficiency of the light-emitting material of the existing organic light-emitting device. question.

The technical scheme of the present invention is as follows:

An organic light-emitting device using a thermally activated delayed fluorescent material as a light-emitting layer material, wherein the thermally activated delayed fluorescent material includes a thermally activated delayed red fluorescent material, a thermally activated delayed blue fluorescent material or a seven-membered ring thermally activated delayed fluorescent material. a kind of,

The general formula of the thermally activated delayed red fluorescent material is:

wherein X ¹ , X ² , X ³ and X ⁴ are each independently selected from NR, O, S, AsR or BiR, and R in said NR, AsR and BiR are each independently selected from hydrogen, deuterium, alkyl, mono Ring aromatic hydrocarbon, fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon; Ring A, Ring C, Ring D, Ring E are independently selected from five-membered ring, six-membered ring or seven-membered ring; R ^A , R ^C , R ^D , R ^E are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl or aromatic groups;

The general formula of the thermally activated delayed blue light fluorescent material is:

Wherein, M ₁₀₁ is B, Ar101 is benzene ring, thiophene or selenophene, X ₁₀₁ is N, Bi or As, Ar102 and Ar103 independently select thiophene, furan, benzene, benzothiophene or benzofuran, R ₁₀₁ -R ₁₀₂ independently select benzene and substituted aryl and heteroaryl;

The general formula of the seven-membered ring thermally activated delayed fluorescent material is:

Wherein, Ar ₂₀₁ -Ar ₂₀₄ are independently selected from benzene, thiophene, furan, pyridine or substituted above-mentioned aryl or heteroaryl, and R ₂₀₁ -R ₂₁₂ are independently selected from hydrogen, deuterium, cyano or alkyl chain One of, X ₁₀₁ is selected from hydrogen, deuterium, halogen, cyano, alkyl chain or benzene, thiophene, furan, carbazole, pyridine, quinoline, isoquinoline and substituted aryl or heteroaryl groups above.

Beneficial effects: The present invention uses the compound of the above general formula as the light-emitting material of the organic light-emitting device, which can provide full-color display for the organic light-emitting device, and has the advantages of high luminous efficiency, high color purity and small efficiency roll-off, etc., which can effectively improve the Device Stability and Operating Life.

Description of drawings

1 is a schematic structural diagram of an organic light-emitting device prepared by the present invention;

2 is a schematic structural diagram of another organic light-emitting device prepared by the present invention;

3 is a graph showing the results of a thermal stability test of a seven-membered ring thermally activated delayed fluorescent material in Example 28 of the present invention;

4 is a graph showing the test results of the emission spectrum of the seven-membered ring thermally activated delayed fluorescent material in Example 28 of the present invention.

Detailed ways

The present invention provides an organic light-emitting device and a display device. In order to make the objectives, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The organic light-emitting device of the present invention and the thermally activated delayed fluorescent material used in the light-emitting layer in the organic light-emitting device are further introduced below through specific examples, wherein the thermally activated delayed fluorescent material includes a thermally activated delayed red fluorescent material , thermally activated delayed blue light fluorescent material and seven-membered ring thermally activated delayed fluorescent material.

The light-emitting layer in the present invention includes a host material and a guest material, and the host material may be mCP, mCBP, CBP, etc., but is not limited thereto; the guest material is the thermally activated delayed red fluorescent material, The thermally activated delayed blue light fluorescent material or the seven-membered ring thermally activated delayed fluorescent material.

The device structure of the organic light-emitting device of the present invention is preferably: substrate/anode/hole transport layer/light-emitting layer/electron transport layer/cathode, substrate/anode/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/ Cathode, Substrate/Anode/Hole Injection Layer/Hole Transport Layer/Light Emitting Layer/Electron Transport Layer/Electron Injection Layer/Cathode, Substrate/Anode/Hole Injection Layer/Hole Transport Layer/Exciton Blocking Layer/Light Emitting Layer /electron transport layer/electron injection layer/cathode, etc. Of course, the structure of the organic light emitting device is not limited to this.

If the specific experimental steps or conditions are not indicated in the examples, the routine experimental steps or conditions described in the literature in this field can be carried out. The reagents or instruments used, if the manufacturer is not indicated, are conventional products that can be obtained from the market.

The compounds not mentioned in the examples are all raw materials obtained through commercial channels. The solvents and reagents used in the examples can be purchased from the domestic chemical market. In addition, those skilled in the art can also synthesize them by known methods.

In one embodiment of the present invention, the material used in the light-emitting layer of the organic light-emitting device is a thermally activated delayed red fluorescent material, and the general formula of the thermally activated delayed red fluorescent material is:

wherein X ¹ , X ² , X ³ and X ⁴ are each independently selected from NR, O, S, AsR or BiR, and R in said NR, AsR and BiR are each independently selected from hydrogen, deuterium, alkyl, mono Ring aromatic hydrocarbon, fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon; Ring A, Ring C, Ring D, Ring E are independently selected from five-membered ring, six-membered ring or seven-membered ring; R ^A , R ^C , R ^D , R ^E are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl or aromatic groups.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

In the formula, X ¹ , X ² , X ³ , X ⁴ are each independently selected from N, As or Bi, and R ₁ to R ₂₈ are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkane group, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbon or fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

In the formula, X ¹ , X ² , X ³ , X ⁴ are each independently selected from N, As or Bi, and R ₁ to R ₂₈ are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkane group, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbon or fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon; X ⁵ , X ⁶ , X ⁷ , X ⁸ are independently selected from monocyclic aromatic hydrocarbons. bond, O, S, or CR _a , wherein R _a is independently selected from substituted or unsubstituted alkyl, mono- or fused-ring aromatic hydrocarbons, mono- or fused-ring heteroaromatic hydrocarbons.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

In the formula, X is independently selected from O or S; R ₁ -R ₂₀ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkane Oxygen, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons, monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

In the formula, X is independently selected from O or S; R ₁ -R ₃₆ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkane Oxygen, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons, monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

In the formula, X is independently selected from O, S or Se.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

In the formula, R ₁ -R ₄₄ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons , monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.

In some embodiments, the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

In one embodiment, the present invention also provides a method for preparing a thermally activated delayed red fluorescent material with the above general formula:

Wherein, Y ¹ -Y ⁴ are independently selected from F, Cl, Br, I; Y ⁵ and Y ⁶ are independently selected from H, F, Cl, Br, I; X is selected from N, As, Bi A sort of. The main flow of the preparation method in the present invention: firstly, the intermediate is prepared by CX coupling reaction; then, n-butyllithium or tert-butyllithium is added to carry out ortho-metalation; then, boron tribromide is added to carry out lithium-boron Or lithium-phosphorus metal exchange, adding a Bronsted base such as N,N-diisopropylethylamine, and performing a tandem Bora Fried-Crafts reaction to obtain the target product.

Examples 1-9 briefly describe the preparation method of the thermally activated delayed red fluorescent material used in the light-emitting layer of the organic light-emitting device of the present invention.

Example 1: Synthesis of Compound 1-F

In a round bottom flask, combine 1-A (1.0eq), 1-B (1.0eq), Pd2(dba _{)3 (} 0.045eq), tri-tert-butylphosphine (0.025eq) and sodium tert-butoxide (2.0 eq) was added to toluene, and the temperature was raised to 100°C for reaction. After the reaction, water and dichloromethane were added, the organic phase was collected, the solvent was spin-dried in vacuo, and passed through a column to obtain compound 1-C. In a 500mL round bottom flask, add 1-C (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; then, add compound 1-D (1.0eq) ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 1-E was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 1-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. After the reaction system was cooled to room temperature, an aqueous sodium acetate solution was added, extracted with dichloromethane, the solvent was rotated to dryness in vacuo, and passed through a silica gel column to obtain the target compound 1-F. The results of 1-F H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.50(dt, J=7.0, 1.3Hz, 4H), 7.36-7.30(m, 12H), 7.27-7.24(m, 4H) ), 7.19–7.14 (m, 3H), 1.35 (s, 18H), 1.28 (d, J=6.8Hz, 12H).

Example 2: Synthesis of Compound 2-F

In a 500mL round-bottom flask, add 3,6-di-tert-butylcarbazole 2-B (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; Then, compound 2-A (1.0 eq) was added, the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 2-C was obtained by filtration. Under nitrogen atmosphere, compound 2-C (1.0eq), diphenylamine (2.2eq), Pd2(dba) ₃ (0.06eq), tri-tert-butylphosphine (0.10eq) and sodium tert-butoxide (3.3eq ₎ were combined It was added to dry toluene, the temperature was raised to 110°C, and the reaction was carried out overnight. After the reaction, it was cooled to room temperature, water and ethyl acetate were added, the organic phase was collected, dried by adding anhydrous magnesium sulfate, the solvent was spin-dried in vacuo, and passed through a silica gel column to obtain the product 2-E. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 2-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C for the reaction. 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. The reaction system was returned to room temperature, an aqueous solution of sodium acetate was added, and the mixture was extracted with dichloromethane. The results of 2-F H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ8.68-8.66(m, 2H), 8.31(d, J=1.5Hz, 2H), 7.66(d, J=7.5Hz, 2H), 7.42 (dd, J=7.5, 1.5Hz, 2H), 7.35–7.24 (m, 8H), 7.19–7.14 (m, 4H), 7.11–7.02 (m, 8H), 1.41 (s, 18H) , 1.31(s, 18H).

Example 3: Synthesis of Compound 3-D

In a 500mL round bottom flask, add phenoxazine 3-B (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; then, add compound 3-A (1.0eq), the temperature was raised to 150°C, and the reaction was performed for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 3-C was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 3-C (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. The reaction system was returned to room temperature, an aqueous sodium acetate solution was added, and the mixture was extracted with dichloromethane. The results of 3-D H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.26(dd,J=7.5,1.7Hz,4H),7.20-7.15(m,8H),7.08(ddd,J=7.3 , 6.3, 2.7Hz, 4H), 6.97 (t, J=7.4Hz, 4H), 6.85 (dd, J=7.5, 1.5Hz, 4H), 6.80–6.77 (m, 4H).

Example 4: Synthesis of Compound 4-F

In a round bottom flask, combine 4-A (1.0eq), _{4-B (1.0eq), Pd2(dba)3 (} 0.045eq), tri-tert-butylphosphine (0.025eq) and sodium tert-butoxide (2.0 eq) was added to toluene, and the temperature was raised to 100°C for reaction. After the reaction, water and dichloromethane were added, the organic phase was collected, the solvent was spin-dried in vacuo, and passed through a column to obtain compound 4-C. In a 500mL round-bottomed flask, 4-C (4.4eq) and cesium carbonate (12.0eq) were added to N,N-dimethylformamide DMF, and stirred at room temperature for 30 minutes; then, compound 4-D (1.0eq) was added ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 4-E was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 4-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. After the reaction system was cooled to room temperature, an aqueous sodium acetate solution was added, extracted with dichloromethane, the solvent was rotated to dryness in vacuo, and passed through a silica gel column to obtain the target compound 4-F. The results of 4-F H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.56(d, J=7.5Hz, 4H), 7.40-7.35(m, 8H), 7.22-7.17(m, 8H), 7.09 (tt, J=7.5, 1.6 Hz, 4H), 6.49 (d, J=7.3 Hz, 4H).

Example 5: Synthesis of Compound 5-F

In a round bottom flask, combine 5-A (1.0eq), 5-B (1.0eq), Pd2(dba _{)3 (} 0.045eq), tri-tert-butylphosphine (0.025eq) and sodium tert-butoxide (2.0 eq) was added to toluene, and the temperature was raised to 100°C for reaction. After the reaction, water and dichloromethane were added, the organic phase was collected, the solvent was spin-dried in vacuo, and passed through a column to obtain compound 5-C. In a 500mL round-bottom flask, add 5-C (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; then, add compound 5-D (1.0eq) ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 5-E was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 5-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. After the reaction system was cooled to room temperature, an aqueous sodium acetate solution was added, extracted with dichloromethane, the solvent was dried in a vacuum, and passed through a silica gel column to obtain the target compound 5-F. The results of 5-F H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.69(dd, J=7.1, 1.8Hz, 4H), 7.62-7.59(m, 4H), 7.38-7.29(m, 16H ), 7.12–7.06 (m, 12H).

Example 6: Synthesis of Compound 6-D

In a 500mL round bottom flask, add 6-B (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; then, add compound 6-A (1.0eq) ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 6-C was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 6-C (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. The reaction system was returned to room temperature, an aqueous solution of sodium acetate was added, and the mixture was extracted with dichloromethane. The results of 6-D H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.78-7.63(m, 20H), 7.60-7.55(m, 12H), 7.51(t, J＝7.4Hz, 4H), 7.45–7.41 (m, 4H), 7.32 (dd, J=7.1, 1.1 Hz, 4H).

Example 7: Synthesis of Compound 7-D

In a 500mL round-bottom flask, compound 7-B (4.4eq) and cesium carbonate (12.0eq) were added to N,N-dimethylformamide DMF, and stirred at room temperature for 30 minutes; then, compound 7-A (1.0 eq), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 7-C was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 7-C (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. The reaction system was returned to room temperature, an aqueous sodium acetate solution was added, and the mixture was extracted with dichloromethane. The results of 7-D H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.39 (dd, J=7.4, 1.6Hz, 4H), 7.30-7.24 (m, 12H), 7.18 (dt, J=7.5 , 1.4Hz, 4H), 7.14 (td, J=7.2, 1.9Hz, 4H), 7.06 (t, J=7.5Hz, 4H).

Example 8: Synthesis of Compound 8-F

In a round bottom flask, combine 8-A (1.0eq), 8-B (1.0eq), Pd2(dba _{)3 (} 0.045eq), tri-tert-butylphosphine (0.025eq) and sodium tert-butoxide (2.0 eq) was added to toluene, and the temperature was raised to 100°C for reaction. After the reaction, water and dichloromethane were added, the organic phase was collected, the solvent was spin-dried in vacuo, and passed through a column to obtain compound 8-C. In a 500mL round-bottomed flask, add 8-C (4.4eq) and cesium carbonate (12.0eq) to N,N-dimethylformamide DMF, and stir at room temperature for 30 minutes; then, add compound 8-D (1.0eq) ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 8-E was obtained by filtration. Under a nitrogen atmosphere, n-butyllithium in n-hexane solution (3.0eq) was slowly added to the tert-butylbenzene solution of precursor 8-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C, the reaction 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. After the reaction system was cooled to room temperature, an aqueous sodium acetate solution was added, extracted with dichloromethane, the solvent was spin-dried in vacuo, and passed through a silica gel column to obtain the target compound 8-F. The results of 8-F hydrogen nuclear magnetic spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.51(d, J=7.5Hz, 4H), 7.31-7.26(m, 8H), 7.13-7.07(m, 16H).

Example 9: Synthesis of Compound 9-F

In a round bottom flask, combine 9-A (1.0eq), 9-B (1.0eq), Pd2(dba _{)3 (} 0.045eq), tri-tert-butylphosphine (0.025eq) and sodium tert-butoxide (2.0 eq) was added to toluene, and the temperature was raised to 100°C for reaction. After the reaction, water and dichloromethane were added, the organic phase was collected, the solvent was spin-dried in vacuo, and passed through a column to obtain compound 9-C. In a 500mL round-bottomed flask, 9-C (4.4eq) and cesium carbonate (12.0eq) were added to N,N-dimethylformamide DMF, and stirred at room temperature for 30 minutes; then, compound 9-D (1.0eq) was added ), the temperature was raised to 150°C, and the reaction was carried out for 12 hours. After the reaction was completed, water was added to dilute, and the solid was obtained by suction filtration, and then refluxed in hot ethanol for 4 hours, and the solid 9-E was obtained by filtration. Under a nitrogen atmosphere, the n-butyllithium solution (3.0eq) in n-hexane was slowly added to the tert-butylbenzene solution of the precursor 9-E (1.0eq) at 0°C, stirred for 0.5 hours, and then heated to 60°C. 2 hours. After the reaction was completed, the temperature was lowered to -40° C., boron tribromide (3.6eq) was slowly added, and stirring was continued at room temperature for 0.5 hours. N,N-diisopropylethylamine (5.0 eq) was added at 0°C and the reaction was continued at 120°C for 5 hours and then stopped. After the reaction system was cooled to room temperature, an aqueous sodium acetate solution was added, extracted with dichloromethane, the solvent was rotated to dryness in vacuo, and passed through a silica gel column to obtain the target compound 9-F. The results of 9-F H NMR spectrum are: ¹ H NMR (500MHz, CDCl ₃ )δ7.48(d, J=7.5Hz, 4H), 7.32-7.27(m, 8H), 7.12-7.05(m, 12H), 6.56 (d, J=7.5 Hz, 4H).

The following Examples 10 to 18 respectively provide an organic light-emitting device, as shown in FIG. 1 , the device structure includes an ITO anode 1 , a hole injection layer (HIL) 2 , a hole transport layer (HTL) 3 , and a light-emitting layer in sequence. (EML) 4, electron transport layer (ETL) 5, electron injection layer (EIL) 6 and cathode 7, and wherein the material used in the light-emitting layer is the thermally activated delayed red fluorescent material prepared in Examples 1-9.

Example 10

The device structure of this example is as follows: ITO/HI(10nm)/HT(50nm)/Host:3wt% compound 1-F(30nm)/ET(30nm)/Liq(1nm)/Al(100nm).

Among them, the material of the hole injection layer is HI, and the total thickness is generally 5-20 nm, which is 10 nm in this embodiment; the material of the hole transport layer is HT, and the total thickness is generally 5-100 nm, which is 50 nm in this embodiment; Host is The host material of the wide bandgap of the organic light-emitting layer, compound 1-F is the guest material and the doping concentration is 3wt%, the thickness of the organic light-emitting layer is generally 1-100nm, this embodiment is 30nm; the material of the electron transport layer is ET, the total thickness Generally, it is 5-100 nm, and in this embodiment, it is 30 nm; the electron injection layer and cathode materials are Liq (1 nm) and metal aluminum (100 nm).

The device performance measurement results for the organic light-emitting device D1 prepared in this example are as follows: by applying a DC voltage, a wavelength of 683 nm, a half-peak width of 35 nm, CIE color coordinates (x, y)=(0.70, 0.29), and external quantum efficiency EQE can be obtained. Glows for 26% red.

Example 11

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced with compound 3-D. The device structure is as follows: ITO/HI(10 nm)/HT(50 nm)/Host:3wt% compound 3-D(30 nm)/ET(30 nm)/Liq(1 nm)/Al(100 nm).

The device performance measurement results for the organic light-emitting device D2 prepared in this example are as follows: by applying a DC voltage, a wavelength of 657 nm, a half-peak width of 35 nm, CIE color coordinates (x, y)=(0.70, 0.30), and external quantum efficiency EQE can be obtained. Glows for 25% red.

Example 12

The preparation method is the same as that in Example 10, except that the guest material of the light-emitting layer is replaced with compound 4-F. The device structure is as follows: ITO/HI(10nm)/HT(50nm)/Host:3wt% compound 4-F(30nm)/ET(30nm)/Liq(1nm)/Al(100nm).

The device performance measurement results for the organic light-emitting device D3 prepared in this example are as follows: by applying a DC voltage, a wavelength of 680 nm, a half-peak width of 28 nm, CIE color coordinates (x, y)=(0.69, 0.32), and external quantum efficiency EQE can be obtained. 26.7% red glow.

Example 13

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced with compound 5-F. The device structure is as follows: ITO/HI(10 nm)/HT(50 nm)/Host:3wt% compound 5-F(30 nm)/ET(30 nm)/Liq(1 nm)/Al(100 nm).

The device performance measurement results for the organic light-emitting device D4 prepared in this example are as follows: by applying a DC voltage, a wavelength of 677 nm, a half-peak width of 33 nm, CIE color coordinates (x, y)=(0.70, 0.28), and external quantum efficiency EQE can be obtained. 22.1% red glow.

Example 14

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced by compound 6-D. The device structure is as follows: ITO/HI(10nm)/HT(50nm)/Host:3wt% compound 6-D(30nm)/ET(30nm)/Liq(1nm)/Al(100nm).

The device performance measurement results for the organic light-emitting device D5 prepared in this example are as follows: by applying a DC voltage, a wavelength of 634 nm, a half-peak width of 30 nm, CIE color coordinates (x, y)=(0.66, 0.31), and external quantum efficiency EQE can be obtained. 25.5% red glow.

Example 15

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced by compound 9-F. The device structure is as follows: ITO/HI(10 nm)/HT(50 nm)/Host: 3 wt% compound 9-F(30 nm)/ET(30 nm)/Liq(1 nm)/Al(100 nm).

The device performance measurement results for the organic light-emitting device D6 prepared in this example are as follows: by applying a DC voltage, a wavelength of 681 nm, a half-peak width of 26 nm, CIE color coordinates (x, y)=(0.71, 0.30), and external quantum efficiency EQE can be obtained. 26.3% red glow.

Example 16

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced by compound 2-F. The device structure is as follows: ITO/HI(10nm)/HT(50nm)/Host:3wt% compound 2-F(30nm)/ET(30nm)/Liq(1nm)/Al(100nm).

The device performance measurement results for the organic light-emitting device D7 prepared in this example are as follows: by applying a DC voltage, a wavelength of 676 nm, a half-peak width of 29 nm, CIE color coordinates (x, y)=(0.71, 0.33), and external quantum efficiency EQE can be obtained. 25.1% red glow.

Example 17

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced with compound 7-D. The device structure is as follows: ITO/HI(10 nm)/HT(50 nm)/Host: 3 wt% compound 7-D(30 nm)/ET(30 nm)/Liq(1 nm)/Al(100 nm).

The device performance measurement results for the organic light-emitting device D8 prepared in this example are as follows: by applying a DC voltage, a wavelength of 688 nm, a half-peak width of 26 nm, CIE color coordinates (x, y)=(0.68, 0.30), and external quantum efficiency EQE can be obtained. 27.5% red glow.

Example 18

The preparation method is the same as that of Example 10, except that the guest material of the light-emitting layer is replaced by compound 8-F. The device structure is as follows: ITO/HI(10nm)/HT(50nm)/Host:3wt% compound 8-F(30nm)/ET(30nm)/Liq(1nm)/Al(100nm).

The device performance measurement results for the organic light-emitting device D9 prepared in this example are as follows: by applying a DC voltage, a wavelength of 684 nm, a half-peak width of 29 nm, CIE color coordinates (x, y)=(0.68, 0.33), and external quantum efficiency EQE can be obtained. 26.4% red glow.

The structural formulas of the various organic materials employed in the above-mentioned embodiments 10-18 are as follows:

The thermally activated delayed red light fluorescent material of the present invention includes a B-π-B linear structure; at the same time, heteroatom structural elements, heavy atoms, seven-membered rings, etc. are introduced to red-shift the fluorescence emission peak, and the fluorescence emission peak of The full width at half maximum is only 20-40nm, so that the thermally activated delayed fluorescent material of red/deep red light can be obtained; at the same time, deuterium element is introduced to improve the life stability of the device. Using the thermally activated delayed red fluorescent material as a light-emitting material of an organic light-emitting device has the advantages of high light-emitting efficiency, high color purity, and small efficiency roll-off.

In one embodiment of the present invention, the material used in the light-emitting layer of the organic light-emitting device is a thermally activated delayed blue fluorescent material, and the general formula of the thermally activated delayed blue fluorescent material is:

Wherein, M ₁₀₁ is B, Ar101 is benzene ring, thiophene or selenophenol, X ₁₀₁ is N, Bi or As, Ar102 and Ar103 are independently selected from thiophene, furan, benzene, benzothiophene or benzofuran, R ₁₀₁ -R ₁₀₂ independently selects benzene and substituted aryl and heteroaryl.

In some embodiments, a plurality to all of the hydrogens in the structural formula of the thermally activated delayed blue fluorescent material are independently selected from deuterium.

In some embodiments, R ₁₀₁ -R ₁₀₂ are independently selected from one of the following structural formulas:

in,

Indicates the attachment site.

In some embodiments, the structural formula of the organic blue fluorescent material is as follows:

Examples 19-21 briefly describe the preparation method of the thermally activated delayed blue light fluorescent material used in the light-emitting layer of the organic light-emitting device of the present invention.

Example 19

This embodiment provides a thermally activated delayed blue fluorescent material, which is denoted as compound 2, and the synthetic route of compound 2 is as follows:

The synthetic method of compound 2 specifically comprises the following steps:

Synthesis of intermediate M3: M1 (8.37 g, 30 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M2 (9.42 g, 30 mmol) was dissolved in toluene (300 ml) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). was 5/1 (volume ratio)) to give intermediate M3 (11.70 g, 70% yield). 1H NMR(500MHz, Chloroform-d) δ8.47(d,J=1.4Hz,2H),7.91(t,J=1.5Hz,1H),7.58-7.51(m,3H),7.48(t,J= 1.6Hz, 1H), 7.34 (dd, J=7.5, 1.5Hz, 2H), 7.31–7.24 (m, 4H), 7.15–7.08 (m, 6H), 1.37 (s, 14H);

Synthesis of intermediate M5: M3 (33.42 g, 60 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M4 (7.8 g, 30 mmol) was dissolved in toluene (200 ml) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). Purification of 5/1 (volume ratio)) gave intermediate M5 (26.54 g, 68% yield) 1H NMR (500 MHz, Chloroform-d) δ 8.47 (d, J=1.4 Hz, 2H), 7.67 (t, J=1.5Hz, 1H), 7.54 (d, J=7.5Hz, 2H), 7.34–7.18 (m, 12H), 7.10 (dqd, J=8.7, 2.8, 1.3Hz, 9H), 6.88 (dd, J =7.5,1.5Hz,1H),1.41(s,14H);

Synthesis of compound 2: Boron tribromide (1.13 mL, 12 mmol) was added to a solution of M5 (3.9 g, 3.0 mmol) in o-dichlorobenzene under nitrogen atmosphere. After stirring at 180°C for 20 hours, the mixture was cooled to room temperature. N,N-Diisopropylethylamine (7.70 mL, 45 mmol) was added at 0 °C and the solvent was removed in vacuo. The crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate: 5/1 (volume ratio)) to obtain compound 2, which was then purified by recrystallization from o-dichlorobenzene to obtain 0.47 g of product with a yield of 12%. 1H NMR(500MHz, Chloroform-d)δ8.47(d,J=1.4Hz,1H),7.51(d,J=7.5Hz,1H),7.47-7.39(m,1H),7.36(q,J= 1.6Hz, 1H), 7.34–7.24 (m, 4H), 7.21–7.16 (m, 1H), 7.14–7.08 (m, 2H), 7.11–7.04 (m, 1H), 7.04 (dd, J=7.5, 1.6Hz, 1H), 1.41(s, 8H).

Example 20

This embodiment provides a thermally activated delayed blue fluorescent material, which is denoted as compound 9, and the synthetic route of compound 9 is as follows:

The synthetic method of compound 9 specifically comprises the following steps:

Synthesis of intermediate M8: M6 (6.81 g, 30 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M7 (9.42 g, 30 mmol) in toluene (300 mL) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). Purification of 5/1 (v/v) yielded intermediate M8 (7.58 g, 50% yield). 1H NMR(500MHz, Chloroform-d)δ7.93(t,J=1.5Hz,1H),7.60(d,J=1.4Hz,2H),7.56(t,J=1.6Hz,1H),7.47(t , J=1.5Hz, 1H), 7.41 (dd, J=9.6, 7.5Hz, 2H), 7.30–7.22 (m, 4H), 7.16–7.10 (m, 4H), 7.07 (tt, J=7.4, 1.5 Hz, 2H), 6.90(dd, J=7.5, 1.6Hz, 2H), 3.82(s, 5H);

Synthesis of intermediate M10: M8 (30.3 g, 60 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M9 (7.8 g, 30 mmol) in toluene (200 mL) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). Purification of 8/1 (v/v) afforded intermediate M10 (26.9 g, 75% yield). 1H NMR (500MHz, Chloroform-d) δ7.57 (d, J=1.6Hz, 1H), 7.37 (dd, J=7.5, 4.1Hz, 1H), 7.34–7.18 (m, 7H), 7.10 (dqd, J=8.7, 2.9, 1.3Hz, 6H), 6.95–6.90 (m, 1H), 6.94–6.85 (m, 1H), 3.83 (s, 3H);

Synthesis of compound 9: Boron tribromide (1.13 mL, 12 mmol) was added to a solution of M10 (3.59 g, 3.0 mmol) in o-dichlorobenzene under nitrogen atmosphere. After stirring at 180°C for 20 hours, the mixture was cooled to room temperature. N,N-Diisopropylethylamine (7.70 mL, 45 mmol) was added at 0 °C and the solvent was removed in vacuo. The crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate was 5/1 (volume ratio)) to obtain compound 9, which was then purified by recrystallization from o-dichlorobenzene to obtain 0.51 g of product with a yield of 14%. 1H NMR (500MHz, Chloroform-d) δ 7.57 (d, J=1.6Hz, 1H), 7.47–7.34 (m, 3H), 7.28 (dtd, J=8.9, 7.4, 1.3Hz, 3H), 7.21– 7.16 (m, 1H), 7.14–7.02 (m, 4H), 6.93 (dd, J=7.5, 1.4Hz, 1H), 3.83 (s, 3H).

Example 21

This embodiment provides a thermally activated delayed blue fluorescent material, which is denoted as compound 4, and the synthetic route of compound 4 is as follows:

The synthetic method of compound 4 specifically comprises the following steps:

Synthesis of intermediate M13: M11 (8.85 g, 30 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M12 (9.42 g, 30 mmol) in toluene (300 mL) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). Purification of 5/1 (v/v) gave intermediate M13 (12.53 g, 73% yield). 1H NMR (500MHz, Chloroform-d) δ7.31-7.20 (m, 4H), 7.15-7.06 (m, 4H), 7.02 (dd, J=7.5, 1.5Hz, 1H), 6.88 (d, J=1.5 Hz,1H),1.28(s,7H);

Synthesis of intermediate M15: M13 (34.44 g, 60 mmol), sodium tert-butoxide (8.60 g, 90 mmol), SPhos (0.493 g, 1.2 mmol), platinum carbon catalyst (0.549 g, 0.60 mmol) and M14 (7.8 g, 30 mmol) in toluene (200 mL) under nitrogen atmosphere. After stirring at 85°C for 15 hours, the mixture was filtered, extracted with chloroform, the aqueous phase was extracted three times with 60 mL of ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, and the crude product was subjected to silica gel column chromatography (petroleum ether/ethyl acetate). Purification at 10/1 (v/v) yielded intermediate M15 (25.59 g, 64% yield). 1H NMR(500MHz, Chloroform-d)δ7.29-7.18(m,1H),7.10(qt,J=2.8,1.4Hz,1H),7.11-6.99(m,1H),6.94-6.85(m,0H ),1.29(s,2H);

Synthesis of compound 4: Boron tribromide (1.13 mL, 12 mmol) was added to a solution of M15 (4.0 g, 3.0 mmol) in o-dichlorobenzene under nitrogen atmosphere. After stirring at 180°C for 20 hours, the mixture was cooled to room temperature. N,N-Diisopropylethylamine (7.70 mL, 45 mmol) was added at 0 °C and the solvent was removed in vacuo. The crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate: 5/1 (volume ratio)) to obtain compound 4, which was then purified by recrystallization from o-dichlorobenzene to obtain 0.24 g of product with a yield of 6%. 1H NMR(500MHz, Chloroform-d)δ7.47-7.39(m,1H),7.28(dtd,J=8.9,7.4,1.3Hz,3H),7.21-7.16(m,1H),7.14-7.05(m , 3H), 7.08–6.99 (m, 4H), 6.92 (d, J=1.5Hz, 1H), 6.72 (dd, J=13.1, 1.5Hz, 1H), 1.29 (s, 9H).

The following Examples 22-24 respectively provide an organic light-emitting device. As shown in FIG. 2 , the organic light-emitting device includes a metal cathode 101 , an electron injection layer 102 , an electron transport layer 103 , and a light-emitting layer that are sequentially stacked from top to bottom. 104. The hole transport layer 105, the hole injection layer 106, the anode 107, and the glass substrate 108, wherein the material used for the light-emitting layer is the thermally activated delayed blue light fluorescent material prepared in Examples 19-21.

Example 22

This embodiment provides an organic light-emitting device based on a thermally activated delayed blue fluorescent material as a light-emitting layer, as shown in FIG. 2, including a metal cathode 101, an electron injection layer 102, an electron transport layer 103, a metal cathode 101, an electron injection layer 102, an electron transport layer 103, The light emitting layer 104 , the hole transport layer 105 , the hole injection layer 106 , the anode 107 and the glass substrate 108 .

Among them, the metal cathode 101 selects aluminum;

The electron injection layer 102 is selected from lithium fluoride;

The electron transport layer 103 selects the compound LET003 with the following structure;

The light-emitting layer 104 is formed by co-doping a host material and a guest material, wherein the host material is selected from the compound mCBP having the following structure, the guest material is selected from compound 2, and the mass ratio of the host material to the guest material is 90:10;

The hole transport layer 105 is selected from the compound NPB with the following structure;

The hole injection layer 106 selects the compound HATCN with the following structure;

The anode 107 is indium tin oxide;

The thermally activated delayed blue fluorescent material (compound 2) provided in this embodiment has the characteristics of narrow emission spectrum, the FWHM is only 28nm, which reflects the good color purity of the material, the external quantum efficiency of the device is 23.3%, and the brightness is 1000cd/m ² , it still maintains 17.3%, the efficiency roll-off is lower, and the color coordinates are (0.14, 0.10).

Example 23

This embodiment provides an organic light-emitting device based on a thermally activated delayed blue fluorescent material as a light-emitting layer, as shown in FIG. 2, including a metal cathode 101, an electron injection layer 102, an electron transport layer 103, a metal cathode 101, an electron injection layer 102, an electron transport layer 103, The light emitting layer 104 , the hole transport layer 105 , the hole injection layer 106 , the anode 107 and the glass substrate 108 .

Among them, the metal cathode 101 selects aluminum;

The electron injection layer 102 is selected from lithium fluoride;

The electron transport layer 103 selects the compound LET003 with the following structure;

The light-emitting layer 104 is formed by co-doping the host material and the guest material, wherein the host material is selected from the compound mCBP with the following structure, the guest material is selected from the compound 9, and the mass ratio of the host material to the guest material is 90:10;

The hole transport layer 105 is selected from the compound NPB with the following structure;

The hole injection layer 106 selects the compound HATCN with the following structure;

The anode 107 is indium tin oxide;

The thermally activated delayed blue fluorescent material (compound 9) provided in this embodiment has the characteristics of narrow emission spectrum, and the FWHM is only 26nm, which reflects the good color purity of the material. The highest external quantum efficiency of the device is up to 20.5%, and the brightness is 1000cd. 15.2% is still maintained at /m2, the efficiency roll ^- off is lower, and the color coordinates are (0.14, 0.13).

Example 24

This embodiment provides an organic light-emitting device based on a thermally activated delayed blue fluorescent material as a light-emitting layer, as shown in FIG. 2, including a metal cathode 101, an electron injection layer 102, an electron transport layer 103, a metal cathode 101, an electron injection layer 102, an electron transport layer 103, The light emitting layer 104 , the hole transport layer 105 , the hole injection layer 106 , the anode 107 and the glass substrate 108 .

Among them, the metal cathode 101 selects aluminum;

The electron injection layer 102 is selected from lithium fluoride;

The electron transport layer 103 selects the compound LET003 with the following structure;

The light-emitting layer 104 is formed by co-doping the host material and the guest material, wherein the host material is selected from the compound mCBP with the following structure, the guest material is selected from the compound 4, and the mass ratio of the host material to the guest material is 90:10;

The hole transport layer 105 is selected from the compound NPB with the following structure;

The hole injection layer 106 selects the compound HATCN with the following structure;

The anode 107 is indium tin oxide;

The thermally activated delayed blue fluorescent material (compound 4) provided in this embodiment has the characteristics of narrow emission spectrum, the FWHM is only 32nm, which reflects the good color purity of the material, the external quantum efficiency of the device is up to 26.7%, and the brightness is 1000cd/ 21.5% remains at m ² , the efficiency roll-off is lower, and the color coordinates are (0.14, 0.12).

By using the thermally activated delayed blue light fluorescent material, the stacking between materials can be effectively improved, the triplet state quenching between molecules can be reduced, and the efficiency roll-off can be reduced; meanwhile, the unique multiple resonance structure endows the material with a narrower fluorescence emission spectrum and higher external quantum efficiency values.

In one embodiment of the present invention, the material used for the light-emitting layer in the organic light-emitting device is a seven-membered ring thermally activated delayed fluorescent material, and the general formula of the seven-membered ring thermally activated delayed fluorescent material is:

Wherein, Ar ₂₀₁ -Ar ₂₀₄ are independently selected from benzene, thiophene, furan, pyridine or substituted above-mentioned aryl or heteroaryl, and R ₂₀₁ -R ₂₁₂ are independently selected from hydrogen, deuterium, cyano or alkyl chain One of, X ₁₀₁ is selected from hydrogen, deuterium, halogen, cyano, alkyl chain or benzene, thiophene, furan, carbazole, pyridine, quinoline, isoquinoline and substituted aryl or heteroaryl groups above.

In some embodiments, the X ₁₀₁ is one of the following groups:

in

Indicates the attachment site.

In some embodiments, the seven-membered ring thermally activated delayed fluorescent material is one of the following chemical structural formulas:

In some embodiments, the present invention also provides a method for preparing the seven-membered ring thermally activated delayed fluorescent material, the chemical reaction process of which is as follows:

Specifically, its preparation method comprises the following steps:

The raw material aromatic boronic acid and the halogenated aromatic group are dissolved in the first solvent, and the first intermediate product is obtained under the first predetermined reaction condition;

The first intermediate product is dissolved in the first solvent, a sufficient amount of iron powder and 3% ammonium chloride solution are added, and after heating to reflux, the solution is poured into water, filtered to obtain a filtrate, concentrated by rotary evaporation, and separated on a silica gel column to obtain the first intermediate product. two intermediate products;

Dissolving the second intermediate product in the second solvent to obtain the third intermediate product aromatic amine under the second predetermined reaction condition;

Dissolving the third intermediate product and difluorobromobenzene in the third solvent, adding cesium carbonate, heating to reflux for 24 hours, pouring the solution into water, filtering to obtain a white precipitate, and using the fourth solvent for recrystallization to obtain the fourth intermediate product;

After the fourth intermediate product is reacted with n-butyllithium at a low temperature, boron tribromide is added to continue the reaction, N,N-diisopropylethylamine is added, and after the reaction is stirred, the seven-membered ring is thermally activated. Delayed fluorescent material.

In this embodiment, the first solvent is toluene, the second solvent is dimethyl sulfoxide, the third solvent is N,N-dimethylformamide, and the fourth solvent is ethanol. The first preset reaction conditions are as follows: the catalyst is 2% mol of tetrakistriphenylphosphine palladium and 5 times the equivalent of potassium carbonate; the reaction temperature is 100-110° C., and the reaction time is 24 hours. The second preset reaction conditions are as follows: the catalyst is twice the equivalent of potassium tert-butoxide, the reaction temperature is 160° C., and the reaction time is 12 hours.

In this embodiment, the aromatic boronic acid is

Described halogenated aromatic group is a kind of in following chemical structural formula:

In some embodiments, another method for preparing a seven-membered ring thermally activated delayed fluorescent material is also provided, and the chemical reaction process is as follows:

Specifically, its preparation method comprises the following steps:

Dissolve the third intermediate product aromatic amine and 5-bromo-2-chloro-1,3-difluorobenzene in the third solvent, add cesium carbonate, heat under reflux for 24 hours, pour the solution into water, and filter to obtain a white precipitate, Use the fourth solvent to recrystallize to obtain the fifth intermediate product;

A substituted or unsubstituted aryl group or a heteroaryl group and the fifth intermediate product are dissolved in the first solvent, and the sixth intermediate product under the first predetermined reaction conditions;

After the sixth intermediate product is reacted with n-butyllithium at low temperature, boron tribromide is added to continue the reaction, N,N-diisopropylethylamine is added, and after stirring the reaction, the seven-membered ring is thermally activated. Delayed fluorescent material.

In this embodiment, the first solvent is toluene, the second solvent is dimethyl sulfoxide, the third solvent is N,N-dimethylformamide, and the fourth solvent is ethanol. The first preset reaction conditions are as follows: the catalyst is 2% mol of tetrakistriphenylphosphine palladium and 5 times the equivalent of potassium carbonate; the reaction temperature is 100-110° C., and the reaction time is 24 hours.

Examples 25-27 briefly describe the preparation method of the seven-membered ring thermally activated delayed fluorescent material used in the light-emitting layer of the organic light-emitting device of the present invention.

Example 25

This embodiment provides a seven-membered ring thermally activated delayed fluorescent material, and the synthetic route of compound 231 is as follows:

The synthetic method of described compound 231 specifically comprises the following steps:

Synthesis of intermediate 1: take a 500mL round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add raw material 1 (2.52 g, 10 mmol), raw material 2 (2.47 g, 12 mmol), tetrakistriphenylphosphine palladium, respectively (231.2 mg, 0.2 mmol), 20 mL of 2 mol/L potassium carbonate aqueous solution, 200 mL of toluene. Heating under reflux for 24 hours, cooling to room temperature, pouring the solution into water, extracting with dichloromethane, drying the organic phase with anhydrous sodium sulfate, and separating on silica gel column to obtain Intermediate 1 (2.40 g, yield 72%). 1H NMR (500MHz, Chloroform-d) δ8.19 (dd, J=7.5, 1.5Hz, 1H), 8.09 (dt, J=7.5, 1.6Hz, 1H), 7.90 (dt, J=7.5, 1.6Hz, 1H), 7.89–7.83 (m, 2H), 7.81 (dd, J=7.5, 1.5Hz, 1H), 7.64 (dd, J=7.5, 1.5Hz, 1H), 7.58 (dt, J=15.5, 7.6Hz) , 2H), 7.36 (td, J=7.6, 5.2Hz, 3H).

Synthesis of Intermediate 2: Take a 200 mL round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add Intermediate 1 (1.67 g, 5 mmol), reduced iron powder (1.68 g, 30 mmol), 3% chloride Ammonium solution 5mL, 100mL toluene. The mixture was heated to reflux for 5 hours, cooled to room temperature, filtered to obtain the filtrate, concentrated by rotary evaporation, and separated by silica gel column to obtain Intermediate 2 (1.47 g, yield 97%). 1H NMR (500MHz, Chloroform-d) δ7.88–7.81 (m, 2H), 7.72 (dt, J=7.5, 1.6Hz, 1H), 7.59 (td, J=7.6, 4.4Hz, 2H), 7.55 ( dt, J=7.5, 1.6Hz, 1H), 7.49 (dd, J=7.5, 1.4Hz, 1H), 7.39–7.32 (m, 3H), 7.18 (t, J=7.5Hz, 1H), 6.83 (dd , J=7.5, 1.5Hz, 1H), 5.28 (s, 1H).

Synthesis of Intermediate 3: Take a 200 mL round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add Intermediate 2 (3.04 g, 10 mmol), potassium tert-butoxide (2.24 g, 20 mmol), 100 mL of dimethylacetate respectively base sulfoxide. Heating under reflux for 12 hours, cooling to room temperature, adding ammonium nitrate solution to quench the reaction, extracting with dichloromethane, drying the organic phase with anhydrous sodium sulfate, and separating on silica gel column to obtain Intermediate 3 (2.25 g, yield 84%). 1H NMR (500MHz, Chloroform-d) δ7.80 (dt, J=7.4, 1.7Hz, 1H), 7.67 (dt, J=7.5, 1.6Hz, 1H), 7.59 (t, J=7.4Hz, 1H) , 7.52 (dd, J=7.5, 1.5Hz, 1H), 7.37 (t, J=7.4Hz, 1H), 7.18 (dd, J=7.5, 1.5Hz, 1H).

Synthesis of intermediate 4: take a 200mL double-neck round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add intermediate 1 (5.87 g, 22 mmol), raw material 3 (1.93 g, 10 mmol), cesium carbonate ( 9.77 g, 30 mmol), 100 mL of N,N-dimethylformamide. It was heated to reflux for 24 hours, cooled to room temperature, poured into water, filtered to obtain a white precipitate, and the crude product was recrystallized from ethanol to obtain Intermediate 2 (5.23 g, yield 76%). 1H NMR(500MHz, Chloroform-d)δ7.81(dt,J=6.8,1.8Hz,2H),7.71(dt,J=7.5,1.6Hz,2H),7.61-7.53(m,6H),7.34- 7.25 (m, 2H), 7.22–7.17 (m, 1H).

Synthesis of compound 231: take a 100mL Schlenk bottle, add Intermediate 2 (3.44g, 5mmol), 50mL tert-butylbenzene, freeze and pump three times with liquid nitrogen, and slowly add 2.4mL n-butyllithium (6mmol, 2.5mol) at 0 degrees /L n-hexane), slowly heated to 60 degrees and continued to react for 4 hours. Cool to -42 degrees, slowly add boron tribromide (0.68 mL, 7 mmol), and slowly warm to room temperature to continue the reaction for 2 hours. N,N-diisopropylethylamine (1.65 mL, 10 mmol) was slowly added under an ice-water bath, and the mixture was gradually heated to 120°C and reacted for 24 hours. The reaction solution was cooled to room temperature, washed three times with sodium acetate solution, the organic phase was collected and dried with anhydrous magnesium sulfate, the crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate was 10/1 (volume ratio)) to obtain compound 231 (0.62 g, 20% yield). 1H NMR (500MHz, Chloroform-d)δ7.80(ddt,J=10.3,6.8,1.8Hz,2H),7.73-7.65(m,2H),7.64-7.51(m,6H),7.25(dd,J =7.5,1.5Hz,1H),6.96(d,J=7.5Hz,1H). APCI-MS: experimental m/z=616.3207, calculated m/z=616.2111.

Example 26

This embodiment provides a seven-membered ring thermally activated delayed fluorescent material, and the synthetic route of compound 253 is as follows:

The synthetic method of compound 253 specifically comprises the following steps:

Synthesis of intermediate 5: take a 200mL double-necked round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add intermediate 3 (5.87 g, 22 mmol), raw material 4 (2.27 g, 10 mmol), cesium carbonate ( 9.77 g, 30 mmol), 100 mL of N,N-dimethylformamide. Heated under reflux for 24 hours, cooled to room temperature, poured the solution into water, and filtered to obtain a white precipitate. The crude product was recrystallized from ethanol to obtain Intermediate 5 (5.86 g, 81% yield). 1H NMR(500MHz, Chloroform-d)δ7.79(dt,J=7.5,1.8Hz,1H),7.69(dt,J=7.8,1.6Hz,1H),7.61-7.51(m,3H),7.27( dd, J=7.5, 1.5 Hz, 1H).

Synthesis of intermediate 6: take a 200 mL round-bottomed flask, connect a spherical condenser, dry and fill with nitrogen, add intermediate 3 (3.61 g, 5 mmol), raw material 5 (3.78 g, 22 mmol), tetrakistriphenylphosphine Palladium (115.6 mg, 0.1 mmol), 10 mL of 2 mol/L aqueous potassium carbonate solution, 100 mL of tetrahydrofuran. Heated under reflux for 24 hours, cooled to room temperature, poured the solution into water, filtered to obtain a white precipitate, and the crude product was recrystallized from ethanol to obtain Intermediate 6 (2.66 g, yield 69%). 1H NMR (500MHz, Chloroform-d) δ8.33 (dd, J=7.5, 1.4Hz, 1H), 8.00–7.95 (m, 1H), 7.91 (dt, J=7.5, 1.5Hz, 1H), 7.80 ( dt, J=7.3, 1.6Hz, 4H), 7.73 (td, J=7.4, 1.6Hz, 1H), 7.69 (dt, J=7.5, 1.6Hz, 4H), 7.65 (d, J=7.5Hz, 1H) ), 7.62–7.48 (m, 13H), 7.41 (s, 2H), 7.27 (dd, J=7.5, 1.5Hz, 4H).

Synthesis of compound 253: take a 100mL Schlenk bottle, add Intermediate 6 (3.85g, 5mmol), 50mL tert-butylbenzene, freeze three times with liquid nitrogen, slowly add 2.4mL n-butyllithium (6mmol, 2.5mol) at 0 degrees /L n-hexane), slowly heated to 60 degrees and continued to react for 4 hours. Cool to -42 degrees, slowly add boron tribromide (0.68 mL, 7 mmol), and slowly warm to room temperature to continue the reaction for 2 hours. N,N-diisopropylethylamine (1.65 mL, 10 mmol) was slowly added under an ice-water bath, and the mixture was gradually heated to 120°C and reacted for 24 hours. The reaction solution was cooled to room temperature, washed three times with sodium acetate solution, the organic phase was collected and dried with anhydrous magnesium sulfate, and the crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate was 10/1 (volume ratio)) to obtain compound 253 (0.67 g, 18% yield). 1H NMR (500MHz, Chloroform-d) δ8.32 (dd, J=7.4, 1.6Hz, 1H), 7.98 (dd, J=7.4, 1.6Hz, 1H), 7.91 (dt, J=7.5, 1.5Hz, 1H), 7.83–7.76 (m, 4H), 7.73 (td, J=7.5, 1.6Hz, 1H), 7.68 (ddd, J=7.5, 3.9, 2.4Hz, 5H), 7.63–7.51 (m, 11H) , 7.51 (dt, J=7.5, 1.8Hz, 3H), 7.31 (s, 2H), 7.25 (dd, J=7.4, 1.6Hz, 2H). APCI-MS: experimental m/z=743.1613, calculated m/z=743.2533.

Example 27

This embodiment provides a seven-membered ring thermally activated delayed fluorescent material, and the synthetic route of compound 298 is as follows:

The synthetic method of compound 298 specifically comprises the following steps:

Synthesis of intermediate 10: The same as the synthesis of intermediate 3, except that starting material 7 (3.89 g, 15 mmol) was used as starting material, intermediate 10 (1.90 g, 74% yield) was obtained. 1H NMR(500MHz, Chloroform-d)δ8.38(s,1H),7.88(dt,J=7.5,1.7Hz,1H),7.73(t,J=7.5Hz,1H),7.61(dt,J= 7.4,1.7Hz,1H),7.54(dd,J=7.5,1.5Hz,1H),7.38(t,J=7.5Hz,1H),7.33(t,J=7.5Hz,1H),7.28(dd, J=7.5, 1.6 Hz, 1H), 7.15 (ddd, J=16.6, 7.4, 1.5 Hz, 2H), 7.09 (s, 1H).

Synthesis of intermediate 11: The same as the synthesis of intermediate 5, except that intermediate 10 (5.65 g, 22 mmol) was used to obtain intermediate 11 (5.62 g, 80% yield). 1H NMR (500MHz, Chloroform-d) δ7.85 (dt, J=7.5, 1.6Hz, 1H), 7.68 (dt, J=7.6, 1.6Hz, 1H), 7.62 (ddd, J=7.7, 7.1, 6.5 Hz, 2H), 7.55 (dd, J=7.5, 1.5Hz, 1H), 7.41 (t, J=7.5Hz, 1H), 7.32 (dd, J=7.4, 1.6Hz, 1H), 7.19–7.12 (m , 3H), 6.83(s, 1H).

Synthesis of intermediate 12: The same as the synthesis of intermediate 6, except that intermediate 11 (3.51 g, 5 mmol) was used to obtain intermediate 12 (2.33 g, 65% yield). 1H NMR (500MHz, Chloroform-d) δ 7.86 (dt, J=7.7, 1.8 Hz, 1H), 7.71–7.57 (m, 4H), 7.55 (dd, J=7.5, 1.7 Hz, 1H), 7.41 ( t, J=7.5Hz, 1H), 7.32 (dd, J=7.4, 1.6Hz, 1H), 7.19–7.11 (m, 4H), 7.09 (s, 1H).

Synthesis of compound 298: The same as the synthesis of compound 253, except that intermediate 12 (3.58 g, 5 mmol) was used to obtain compound 298 (0.83 g, 24% yield). 1H NMR (500MHz, Chloroform-d) δ7.90 (dt, J=7.1, 1.7Hz, 2H), 7.71–7.54 (m, 12H), 7.29 (dd, J=7.5, 1.7Hz, 2H), 7.18– 7.10(m, 6H), 7.00(s, 2H). APCI-MS: experimental m/z=690.1894, calculated m/z=690.1915.

In view of the excellent light-emitting properties and narrowed fluorescence emission spectrum of the above-mentioned seven-membered ring thermally activated delayed fluorescent material, the present invention provides the following Examples 28-30, respectively providing an organic light-emitting device, comprising a light-emitting layer, and the light-emitting layer uses The material is the seven-membered ring thermally activated delayed fluorescent material prepared in Examples 25-27.

Example 28

The present invention provides an organic light-emitting device based on a seven-membered ring thermally activated delayed fluorescent material as a light-emitting layer. As shown in FIG. 2, a metal cathode 101, an electron injection layer 102, an electron transport layer 103, a light-emitting layer 104 , hole transport layer 105 , hole injection layer 106 , anode 107 and glass substrate 108 . Among them, preferably, the metal cathode 101 is selected from aluminum, the electron injection layer 102 is selected from lithium fluoride, and the electron transport layer 103 is selected from the following structure

The compound LET003; the light-emitting layer 104 is formed by co-doping the host material and the guest material, wherein the host material is selected to have the following structure

The compound mCBP, the guest material is compound 298

The mass ratio of the host material and the guest material doping is 90:10; the hole transport layer 105 is selected to have the following structure

The compound NPB; the hole injection layer 106 is selected to have the following structure

The compound HATCN; the anode 107 selects indium tin oxide.

Example 29

An organic electroluminescence device is provided, which is different from the organic electroluminescence device provided in Example 28 in that compound 231 is selected as the material of the light-emitting layer.

Example 30

An organic electroluminescent device is provided, which is different from the organic electroluminescent device provided in Example 28 in that compound 253 is selected as the material of the light-emitting layer.

The thermal stability test was carried out on the seven-membered ring thermally activated delayed fluorescent material prepared in Example 28. The results are shown in Figure 3. It can be seen from Figure 3 that the decomposition temperature of the seven-membered ring thermally activated delayed fluorescent material is 415 degrees. , indicating that the seven-membered ring thermally activated delayed fluorescent material has excellent thermal stability.

The emission spectrum of the seven-membered ring thermally activated delayed fluorescent material prepared in Example 28 is tested, and the results are shown in Figure 4. It can be seen from Figure 4 that the emission spectrum of the seven-membered ring thermally activated delayed fluorescent material is only 28nm , indicating that the seven-membered ring thermally activated delayed fluorescent material has the characteristics of narrow emission spectrum, which reflects the good color purity of the material.

In the present invention, by using the above-mentioned seven-membered ring thermally activated delayed fluorescent material in the light-emitting layer of the organic light-emitting device, the introduction of the seven-membered ring can effectively improve the stacking between materials, reduce the triplet quenching of the molecules, and reduce the efficiency roll-off , improve the stability and working life of the device; at the same time, the unique boron-nitrogen multiple resonance structure endows the material with a narrow fluorescence emission spectrum and a high external quantum efficiency value.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (14)

1. An organic light-emitting device using a thermally activated delayed fluorescent material as a light-emitting layer material, wherein the thermally activated delayed fluorescent material includes a thermally activated delayed red fluorescent material, a thermally activated delayed blue fluorescent material or a seven-membered ring thermally activated delayed fluorescent material One of the fluorescent materials, the general formula of the thermally activated delayed red fluorescent material is:

   

   wherein X ¹ , X ² , X ³ and X ⁴ are each independently selected from NR, O, S, AsR or BiR, and R in said NR, AsR and BiR are each independently selected from hydrogen, deuterium, alkyl, mono Ring aromatic hydrocarbon, fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon; Ring A, Ring C, Ring D, Ring E are independently selected from five-membered ring, six-membered ring or seven-membered ring; R ^A , R ^C , R ^D , R ^E are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl or aromatic groups;

   The general formula of the thermally activated delayed blue light fluorescent material is:

   

   Wherein, M ₁₀₁ is B, Ar101 is benzene ring, thiophene or selenophene, X ₁₀₁ is N, Bi or As, Ar102 and Ar103 independently select thiophene, furan, benzene, benzothiophene or benzofuran, R ₁₀₁ -R ₁₀₂ independently select benzene and substituted aryl and heteroaryl;

   The general formula of the seven-membered ring thermally activated delayed fluorescent material is:

   

   Wherein, Ar ₂₀₁ -Ar ₂₀₄ are independently selected from benzene, thiophene, furan, pyridine or substituted above-mentioned aryl or heteroaryl, and R ₂₀₁ -R ₂₁₂ are independently selected from hydrogen, deuterium, cyano or alkyl chain One of, X ₁₀₁ is selected from hydrogen, deuterium, halogen, cyano, alkyl chain or benzene, thiophene, furan, carbazole, pyridine, quinoline, isoquinoline and substituted aryl or heteroaryl groups above.
2. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

   

   In the formula, X ¹ , X ² , X ³ , X ⁴ are each independently selected from N, As or Bi, and R ₁ to R ₂₈ are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkane group, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbon or fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon.
3. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

   

   In the formula, X ¹ , X ² , X ³ , X ⁴ are each independently selected from N, As or Bi, and R ₁ to R ₂₈ are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkane group, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbon or fused ring aromatic hydrocarbon, monocyclic heteroaromatic hydrocarbon or fused ring heteroaromatic hydrocarbon; X ⁵ , X ⁶ , X ⁷ , X ⁸ are independently selected from monocyclic aromatic hydrocarbons. bond, O, S, or CR _a , wherein R _a is independently selected from substituted or unsubstituted alkyl, mono- or fused-ring aromatic hydrocarbons, mono- or fused-ring heteroaromatic hydrocarbons.
4. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

   

   In the formula, X is independently selected from O or S; R ₁ -R ₂₀ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkane Oxygen, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons, monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.
5. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

   

   In the formula, X is independently selected from O or S; R ₁ -R ₃₆ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkane Oxygen, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons, monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.
6. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

   

   In the formula, X is independently selected from O, S or Se.
7. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is shown in the following formula:

   

   In the formula, R ₁ -R ₄₄ are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl, alkenyl, alkoxy or thioalkoxy, monocyclic aromatic hydrocarbons or fused ring aromatic hydrocarbons , monocyclic heteroaromatic hydrocarbons or fused ring heteroaromatic hydrocarbons.
8. The organic light-emitting device according to claim 1, wherein the structure of the thermally activated delayed red fluorescent material is selected from one of the following formulas:

   

   

   

   

   

   

   

   

   

   

   

   
9. The organic light-emitting device according to claim 1, wherein a plurality of hydrogens in the structural formula of the thermally activated delayed blue fluorescent material are independently selected from deuterium.
10. The organic light-emitting device according to claim 1, wherein R ₁₀₁ -R ₁₀₂ are independently selected from one of the following structural formulas:

    

    in,

    

    Indicates the attachment site.
11. The organic light-emitting device according to claim 10, wherein the structural formula of the organic blue fluorescent material is as follows:

    

    

    

    

    

    

    

    

    

    

    

    

    
12. The organic light-emitting device according to claim 1, wherein the X ₁₀₁ is one of the following groups:

    

    

    in

    

    Indicates the attachment site.
13. The organic light-emitting device according to claim 1 or 12, wherein the seven-membered ring thermally activated delayed fluorescent material is one of the following chemical structural formulas:

    

    

    

    

    

    

    

    

    

    

    

    
14. A display device, characterized by comprising the organic light-emitting device according to claim 1 .

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