Light-emitting devices and display modules

Abstract

This disclosure provides a light-emitting device and a display module. At least one of the light-emitting layer, the hole transport structure, and the electron transport structure of the light-emitting device includes a compound having a structure as shown in Formula 1.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting device and a display module. Background Technology

[0002] With the improvement of living standards, OLED light-emitting devices have attracted increasing attention. OLED light-emitting devices have a series of advantages, including an all-solid-state structure, self-emissive nature, fast response speed, high brightness, wide viewing angle, and flexible display capability. However, current light-emitting devices still need further improvement. Summary of the Invention

[0003] The purpose of this disclosure is to provide a light-emitting device and a display module.

[0004] According to one aspect of this disclosure, a light-emitting device is provided, comprising:

[0005] Anode and cathode arranged opposite each other;

[0006] A light-emitting layer is disposed between the anode and the cathode;

[0007] A hole transport structure is disposed between the anode and the light-emitting layer;

[0008] An electron transport structure is disposed between the cathode and the light-emitting layer;

[0009] Wherein, at least one of the light-emitting layer, the hole transport structure, and the electron transport structure comprises a compound having a structural formula as shown in Formula 1:

[0010]

[0011] Where m and n are integers greater than or equal to 0 and less than or equal to 4, and m+n≥1;

[0012] R1 and R2 are each independently selected from hydrogen, deuterium, fluorine, alkyl, cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and...

[0013] Ar1 and Ar2 are each independently selected from substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups, and L1 and L2 are each independently selected from single bonds, substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups.

[0014] Ring A is selected from C5-C12 cycloalkyl groups.

[0015] Furthermore, the hole transport structure includes a hole transport material, which comprises a compound having a structure as shown in Formula 1, where n is an integer greater than or equal to 1, and the structure shown in Formula 1 is:

[0016]

[0017] Furthermore, Ar1 and Ar2 are each independently selected from... as well as

[0018] Furthermore, the hole transport material includes the following compounds:

[0019]

[0020]

[0021]

[0022] Furthermore, the electron transport structure includes an electron transport material, which comprises a compound having a structure as shown in Formula 1, where n is an integer greater than or equal to 1, and the structure shown in Formula 1 is:

[0023]

[0024] Among them, L3, L4, and L5 are each independently selected from single-bonded, substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups;

[0025] X1, X2, and X3 are each independently selected from nitrogen and... R3 is selected from hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; at least one of X1, X2, and X3 is nitrogen;

[0026] Ar3 and Ar4 are each independently selected from hydrogen, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups.

[0027] Furthermore, L3 is selected from as well as

[0028] Furthermore, Ar3 and Ar4 are each independently selected from phenyl groups.

[0029] Furthermore, the electron transport material includes the following compounds:

[0030]

[0031]

[0032] Furthermore, the light-emitting layer comprises a host material and a dopant material, wherein the host material comprises a compound having a structure as shown in Formula 1, where m is an integer greater than or equal to 1, and the structure shown in Formula 1 is:

[0033]

[0034] Where t is an integer greater than or equal to 0 and less than or equal to 4;

[0035] X4 is independently selected from oxygen, sulfur, and... X5, X6, and X7 are each independently selected from oxygen, sulfur, and nitrogen; R4 is selected from hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl.

[0036] Ar5 and Ar6 are each independently selected from hydrogen, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups;

[0037] L6, L7, and L8 are each independently selected from single-bonded, substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups;

[0038] The B ring is selected from aromatic rings, fused aromatic rings, and fused heterocyclic aromatic rings.

[0039] Furthermore, R4 is selected from phenyl and biphenyl.

[0040] Furthermore, Ar5 and Ar6 are each independently selected from phenyl and biphenyl.

[0041] Furthermore, the host material includes the following compounds:

[0042]

[0043]

[0044] Furthermore, the light-emitting layer is a blue light-emitting layer, and the hole transport structure includes:

[0045] A hole injection layer is disposed on the side of the anode facing the light-emitting layer;

[0046] A hole transport layer is disposed on the side of the hole injection layer facing the light-emitting layer;

[0047] An electron blocking layer is disposed between the hole transport layer and the light-emitting layer;

[0048] The electron transport structure includes:

[0049] An electron injection layer is disposed on the side of the cathode facing the light-emitting layer;

[0050] An electron transport layer is disposed on the side of the electron injection layer facing the light-emitting layer;

[0051] A hole blocking layer is disposed on the side of the electron transport layer facing the light-emitting layer;

[0052] Wherein, at least one of the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer, and the hole blocking layer includes a compound having a structure as shown in Formula 1.

[0053] Furthermore, the light-emitting layer is a red light-emitting layer or a green light-emitting layer, and the hole transport structure includes:

[0054] A hole injection layer is disposed on the side of the anode facing the light-emitting layer;

[0055] A hole transport layer is disposed on the side of the hole injection layer facing the light-emitting layer;

[0056] An electron blocking layer is disposed between the hole transport layer and the light-emitting layer;

[0057] The electron transport structure includes:

[0058] An electron injection layer is disposed on the side of the cathode facing the light-emitting layer;

[0059] An electron transport layer is disposed on the side of the electron injection layer facing the light-emitting layer;

[0060] A hole blocking layer is disposed on the side of the electron transport layer facing the light-emitting layer;

[0061] Wherein, at least one of the hole injection layer, the hole transport layer, the electron blocking layer, the electron injection layer, the electron transport layer, the hole blocking layer, and the light-emitting layer includes a compound having a structure as shown in Formula 1.

[0062] According to one aspect of this disclosure, a display module is provided, comprising:

[0063] Substrate;

[0064] A driving circuit layer is disposed on one side of the substrate;

[0065] The light-emitting device is disposed on one side of the driving circuit layer. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of a light-emitting device according to an embodiment of the present disclosure.

[0067] Explanation of reference numerals in the attached diagram: 1. Anode; 2. Hole injection layer; 3. Hole transport layer; 4. Electron blocking layer; 5. Light emitting layer; 6. Hole blocking layer; 7. Electron transport layer; 8. Electron injection layer; 9. Cathode. Detailed Implementation

[0068] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0069] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used in this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar words used in this disclosure and the claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “a” or “one,” and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. “A plurality” or “several” indicates two or more. Unless otherwise indicated, the terms “front,” “rear,” “lower,” and / or “upper,” and similar words are for ease of description only and are not limited to a location or spatial orientation. The terms “comprising,” “including,” and similar words mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The singular forms “a,” “the,” and “the” used in this disclosure and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0070] In related technologies, OLED light-emitting devices belong to the injection-type light-emitting category. Under voltage driving, holes are injected into the light-emitting layer by the anode, and electrons are injected into the light-emitting layer by the cathode. Holes and electrons meet and recombine in the light-emitting layer to form excitons, which then recombine and transfer energy to the light-emitting material. To improve the stability and efficiency of the light-emitting device, the injection of electrons and holes should be balanced. Introducing an injection layer (EIL / HIL) and a transport layer (ETL / HTL) into the light-emitting device to form a multilayer structure helps to balance the injection of electrons and holes, thereby increasing the recombination probability and the quantum efficiency of light emission in the light-emitting layer.

[0071] Currently, OLED light-emitting devices are typically fabricated using vacuum evaporation, where organic molecules are deposited onto a substrate to form a dense thin layer. For common OLED materials, these organic molecules are usually aromatic conjugated structures. During the evaporation process, due to the severe planarization of organic molecules and strong intermolecular forces, they easily form crystalline or aggregated states on the substrate, leading to interface degradation and reduced device efficiency and stability. Furthermore, the poor solubility of the material results in poor cleaning of the mass-produced evaporation mask.

[0072] To address the aforementioned problems, this disclosure provides a light-emitting device. For example... Figure 1 As shown, the light-emitting device may include an anode 1, a cathode 9, a light-emitting layer 5, a hole transport structure, and an electron transport structure, wherein:

[0073] The anode 1 and cathode 9 are disposed opposite to each other. The light-emitting layer 5 is disposed between the anode 1 and the cathode 9. The hole transport structure is disposed between the anode 1 and the light-emitting layer 5. The electron transport structure is disposed between the cathode 9 and the light-emitting layer 5. At least one of the light-emitting layer 5, the hole transport structure, and the electron transport structure comprises a compound having the structural formula shown in Formula 1.

[0074]

[0075] Where m and n are integers greater than or equal to 0 and less than or equal to 4, and m+n≥1;

[0076] R1 and R2 are each independently selected from hydrogen, deuterium, fluorine, alkyl, cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and...

[0077] Ar1 and Ar2 are each independently selected from substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups, and L1 and L2 are each independently selected from single bonds, substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups.

[0078] Ring A is selected from C5-C12 cycloalkyl groups.

[0079] The light-emitting device of this disclosure has ring A selected from C5-C12 cycloalkyl groups. The compound having the structure shown in Formula 1 is a cycloalkylfluorene structure. Compared with a single aliphatic alkyl group, this disclosure can increase the spatial structure of the molecule, thereby improving stability. At the same time, it can improve the solubility of the vapor deposition material and facilitate the cleaning of the vapor deposition mask.

[0080] The light-emitting device according to the embodiments of this disclosure will now be described in detail:

[0081] The aforementioned ring A can be selected from C5-C12 cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexane, norbornene, adamantyl, etc., exhibiting low ring strain and good stability. When the ring A is adamantyl, the adamantyl group is a highly symmetrical cage-like hydrocarbon with a rigid system and symmetrical structure, resulting in low molecular strain energy, good thermal stability, and a high melting point. This can effectively increase the glass transition temperature of the material and enhance its stability (introducing the 9-position substitution of the methyl group in fluorene can further improve stability). Applying this to organic electroluminescent devices or photoelectric conversion devices can effectively improve device lifespan and mass production stability.

[0082] R1 and R2 mentioned above can be the same, or they can be different. When n is greater than or equal to 2, any adjacent R1 can form a saturated or unsaturated cycle. When m is greater than or equal to 2, any adjacent R2 can form a saturated or unsaturated cycle. Ar1 and Ar2 mentioned above can be the same, or they can be different.

[0083] The hole transport structure may include a hole injection layer 2, a hole transport layer 3, and an electron blocking layer 4. The hole injection layer 2 may be disposed on the side of the anode 1 facing the light-emitting layer 5. The hole transport layer 3 may be disposed on the side of the hole injection layer 2 facing the light-emitting layer 5. The electron blocking layer 4 (Prime) may be disposed between the hole transport layer 3 and the light-emitting layer 5.

[0084] The hole transport structure may include a hole transport material. This hole transport material may include compounds having the structure shown in Formula 1. Taking a red or green light-emitting layer 5 in a light-emitting device as an example, the hole injection layer 2, hole transport layer 3, and electron blocking layer 4 in the light-emitting device may all include compounds having the structure shown in Formula 1. Taking a blue light-emitting layer 5 in a light-emitting device as an example, the hole injection layer 2 and hole transport layer 3 in the light-emitting device may both include compounds having the structure shown in Formula 1, that is, the electron blocking layer 4 in the light-emitting device does not include compounds having the structure shown in Formula 1. It should be noted that blue light excitation requires higher energy (and thus higher material stability requirements), and the host material in the blue light-emitting layer 5 has a large band gap difference. Therefore, the electron blocking layer 4 material in the light-emitting device with the blue light-emitting layer 5 needs to have a deeper energy level to match the HOMO energy level gap of the host material. The cycloalkylfluorene in this disclosure can reduce single bond torsion, increase planarity, increase conjugation, and make the HOMO energy level shallower.

[0085] The thickness of the hole injection layer 2 can be 5 nm to 20 nm. When the material of the hole injection layer 2 does not contain a compound having the structural formula shown in Formula 1, the material of the hole injection layer 2 can be selected from HATCN, CuPc, etc.; of course, the material of the hole injection layer 2 can be selected from p-type doped materials, such as NPB:F4TCNQ, TAPC:MnO3, etc., and the doping concentration is 0.5% to 10%. The thickness of the hole transport layer 3 can be 100 nm to 140 nm, and the highest occupied orbital (HOMO) energy level of the hole transport layer 3 needs to be between -5.2 eV and -5.6 eV. When the material of the hole transport layer 3 does not contain a compound having the structural formula shown in Formula 1, the material of the hole transport layer 3 can include aromatic amine materials. The thickness of the electron blocking layer 4 can be 1 nm to 30 nm.

[0086] Furthermore, taking a hole transport material comprising a compound having a structural formula as shown in Formula 1 as an example, the structural formula shown in Formula 1 can be:

[0087]

[0088] In the structure shown in Equation 1-1, n can be an integer greater than or equal to 1, and Ar1 and Ar2 are each independently selected from... as well as

[0089] For example, compounds having the structural formula shown in Formula 1-1 are selected from the following compounds:

[0090]

[0091]

[0092] The synthesis of the above-mentioned compound H-4 is as follows:

[0093]

[0094] Compound 1 (CAS: 659.75-65-7) (53.51 g, 200 mmol) and THF (452 ​​mL) were placed in a dry round-bottom flask under nitrogen protection and dissolved until clear at -80°C to -90°C. Then, a hexane solution of n-BuLi (96 mL, 240 mmol) was slowly added dropwise to the reaction system, and the reaction was carried out at -80°C to -90°C for 1 h. Finally, adamantane (24.035 g, 160 mmol) was dissolved in THF (100 mL, 452 mL). After dissolving (mL), the solution was slowly added dropwise to the reaction system. The reaction was carried out at -80℃ to -90℃ for 1 hour, then allowed to rise naturally to room temperature and stirred for 6 hours. 5 wt% hydrochloric acid was added to the reaction solution until pH < 7. After thorough stirring, dichloromethane (DCM) was added for extraction. The organic phases were combined, washed with water until neutral, dried with anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. The resulting oily substance was added to a flask containing n-heptane, heated to reflux until a clear solution was obtained, and recrystallized at -20℃ to give compound 2.

[0095]

[0096] Under nitrogen protection, compound 2 (33.81 g, 100 mmol) was weighed and glacial acetic acid (280 mL) was measured. The mixture was stirred at 50-60 °C until the reaction solution was completely clear. Concentrated sulfuric acid (0.54 mL, 98 wt%) was added dropwise, and the temperature was raised to 70-80 °C. After stirring for 30 min, the reaction solution was allowed to cool naturally to room temperature. Deionized water (500 mL) was added, and the mixture was stirred thoroughly and filtered. The filter cake was rinsed with deionized water until neutral and placed in a vacuum drying oven to dry for 1 h. It was dissolved in DCM (dichloromethane), and anhydrous sodium sulfate was added and dried for 30 min. After filtration, the solvent was removed under reduced pressure. Heptane was added, and DCM was distilled off. The crude product was recrystallized at -20 °C, filtered, and dried in a vacuum drying oven to obtain intermediate 1 (C22H23N, yield 82%).

[0097]

[0098] Intermediate 1 (3.01 g, 10 mmol) and compound 3 (CAS: 92-66-0) (5.83 g, 25 mmol) were dissolved in 100 mL of toluene solution. Nitrogen gas was purged three times. 10% tri-tert-butylphosphine solution and Pd2(dba)3 were rapidly added dropwise to the reaction flask, followed by the rapid addition of 2.9 g (30 mmol) sodium tert-butoxide. The mixture was heated under reflux for 12 h. After the reaction was completed, the reactants were poured into water, and the organic phase was extracted. The mixture was washed three times with water, dried over anhydrous sodium sulfate, filtered, and the organic solvent was evaporated by rotary evaporation to obtain the crude product. The crude product was passed through a silica gel column, recrystallized, and dried under vacuum to obtain compound H-4 (C46H39N) (4.72 g, yield 78%).

[0099] The synthesis of the above-mentioned compound H-5 is as follows:

[0100]

[0101] Compound 4 and THF (452 ​​mL) were placed in a dry round-bottom flask under nitrogen protection and dissolved until clear at -80°C to -90°C. Then, a hexane solution of n-BuLi (96 mL, 240 mmol) was slowly added dropwise to the reaction system, and the reaction was carried out at -80°C to -90°C for 1 h. Then, adamantane (24.035 g, 160 mmol) was dissolved in THF (100 mL) and slowly added dropwise to the reaction system. The reaction was carried out at -80°C to -90°C for 1 h, and then allowed to rise naturally to room temperature and stirred for 6 h. 5 wt% hydrochloric acid was added to the reaction solution until pH < 7. After stirring thoroughly, dichloromethane (DCM) was added for extraction. The organic phases were combined, washed with water until neutral, dried with anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. The resulting oily substance was added to a flask containing n-heptane, heated to reflux until a clear solution was obtained, and recrystallized at -20°C to obtain compound 5.

[0102]

[0103] Compound 5 (33.51 g, 100 mmol) and compound 6 (CAS: 73183-34-3) (25.39 g, 100 mmol) were placed in a reaction flask, 150 ml of DMF was added, nitrogen gas was evacuated three times, PdCl2 (dppf) was added, followed by potassium tert-butoxide, and the reaction was carried out for 10 h. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, washed three times with water, the organic solvent was evaporated by rotary evaporation, and dried in a vacuum drying oven to obtain compound 7 (32.47 g, yield 76%).

[0104]

[0105] Compound 7 (42.73 g, 100 mmol) and compound 8 (CAS: 7314-85-4) (21.5 g, 100 mmol) were placed in a reaction flask, 200 ml of THF was added, nitrogen gas was evacuated three times, Pd(PPh3)4 was added, followed by potassium carbonate and the reaction was carried out for 8 h. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, washed three times with water, the organic solvent was evaporated by rotary evaporation, and dried in a vacuum drying oven to obtain intermediate 2 (C32H37N) (22.2 g, yield 51%).

[0106]

[0107] Intermediate 2 and the above-mentioned compound 3 (CAS: 92-66-0) (5.83 g, 25 mmol) were dissolved in 100 ml of toluene solution. Nitrogen gas was purged three times. 10% tri-tert-butylphosphine solution and Pd2(dba)3 were rapidly added dropwise to the reaction flask, followed by the rapid addition of 2.9 g (30 mmol) sodium tert-butoxide. The mixture was heated under reflux for 12 h. After the reaction was completed, the reactants were poured into water, the organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, filtered, and the organic solvent was evaporated by rotary evaporation to obtain the crude product. The crude product was passed through a silica gel column, recrystallized, and dried under vacuum to obtain compound H-5 (C56H53N) (4.73 g, yield 64%).

[0108] The electron transport structure may include an electron injection layer 8, an electron transport layer 7, and a hole blocking layer 6. The electron injection layer 8 may be disposed on the side of the cathode 9 facing the light-emitting layer 5. The electron transport layer 7 may be disposed on the side of the electron injection layer 8 facing the light-emitting layer 5. The hole blocking layer 6 may be disposed on the side of the electron transport layer 7 facing the light-emitting layer 5. Furthermore, the thickness of the electron injection layer 8 may be 0.5 nm to 10 nm. The thickness of the electron transport layer 7 may be 20 nm to 70 nm. The thickness of the hole blocking layer 6 may be 2 nm to 20 nm.

[0109] The electron transport structure includes an electron transport material. The electron injection layer 8, the electron transport layer 7, and the hole blocking layer 6 may all include the electron transport material. The electron transport material may include a compound having the structural formula shown in Formula 1.

[0110] Furthermore, taking an electron transport layer 7 comprising a compound having a structure as shown in Formula 1 as an example, the structure shown in Formula 1 can be:

[0111]

[0112] In the structural formulas shown in Formulas 1-2, L3, L4, and L5 are each independently selected from single bonds, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups; X1, X2, and X3 are each independently selected from nitrogen and... Furthermore, the L3 can be selected from... as well as R3 is selected from hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; at least one of X1, X2, and X3 is nitrogen; Ar3 and Ar4 are each independently selected from hydrogen, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; further, Ar3 and Ar4 are each independently selected from phenyl. The connection of L3, L4, and L5 is preferably meta or ortho, and the twisted structure is beneficial for raising the triplet energy level.

[0113] For example, the electron transport material may include the following compounds:

[0114]

[0115]

[0116] The synthesis of the above compound E-3 is as follows:

[0117]

[0118] Compound 9 (CAS: 850264-92-5) (100 mmol) and compound 10 (100 mmol) were placed in a reaction flask, 150 ml of DMF was added, nitrogen gas was evacuated three times, PdCl2 (dppf) was added, followed by potassium tert-butoxide and reacted for 10 h. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, washed three times with water, the organic solvent was evaporated by rotary evaporation, and dried in a vacuum drying oven to obtain intermediate 3.

[0119]

[0120] Compound 11 (CAS: 1805001-22-2) (53.51 g, 200 mmol) and THF (452 ​​mL) were placed in a dry round-bottom flask under nitrogen protection and dissolved until clear at -80°C to -90°C. Then, a hexane solution of n-BuLi (96 mL, 240 mmol) was slowly added dropwise to the reaction system, and the reaction was carried out at -80°C to -90°C for 1 h. Then, adamantane (24.035 g, 160 mmol) was dissolved in THF (100 mL) and added dropwise. The solution was slowly added dropwise to the reaction system and reacted at -80°C to -90°C for 1 hour. The mixture was then allowed to rise naturally to room temperature and stirred for 6 hours. 5 wt% hydrochloric acid was added to the reaction solution until the pH was <7. After thorough stirring, dichloromethane (DCM) was added for extraction. The organic phases were combined, washed with water until neutral, dried with anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. The resulting oily substance was added to a flask containing n-heptane, heated to reflux until a clear solution was obtained, and recrystallized at -20°C to give compound 12 (43.28-30.6 g, yield 80%).

[0121]

[0122]

[0123] Under nitrogen protection, compound 12 (33.81 g, 100 mmol) was weighed and glacial acetic acid (280 mL) was measured. The mixture was stirred at 50-60 °C until the reaction solution was completely clear. Concentrated sulfuric acid (0.54 mL, 98 wt%) was added dropwise, and the temperature was raised to 70-80 °C. After stirring for 30 min, the reaction solution was allowed to cool naturally to room temperature. Deionized water (500 mL) was added, and the mixture was stirred thoroughly and filtered. The filter cake was rinsed with deionized water until neutral and dried in a vacuum drying oven for 1 h. It was dissolved in DCM (dichloromethane), dried with anhydrous sodium sulfate for 30 min, filtered, and the solvent was removed under reduced pressure. Heptane was added, and DCM was distilled off. The crude product was recrystallized at -20 °C, filtered, and dried in a vacuum drying oven to obtain intermediate 4 (28.88 g, 90.0%) (C22H21Cl).

[0124]

[0125] Intermediate 4 (100 mmol) and intermediate 3 (100 mmol) were placed in a reaction flask, 200 ml of THF was added, nitrogen gas was evacuated three times, Pd(PPh3)4 was added, followed by potassium carbonate and reacted for 8 h. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, washed three times with water, the organic solvent was evaporated by rotary evaporation, and dried in a vacuum drying oven to obtain compound E-3.

[0126] The light-emitting layer 5 may include a host material and a dopant material, and the doping ratio may be 0.5%-20%. The thickness of the light-emitting layer 5 may be 5nm-40nm. Taking the light-emitting layer 5 as a red light-emitting layer 5 or a green light-emitting layer 5 as an example, the host material in the light-emitting layer 5 may include a compound having the structural formula shown in Formula 1. Taking the light-emitting layer 5 in the light-emitting device as a blue light-emitting layer 5 as an example, at least one of the hole transport structure and the electron transport structure in the light-emitting device may include a compound having the structural formula shown in Formula 1, and the host material of the blue light-emitting layer 5 does not include a compound having the structural formula shown in Formula 1. The blue light-emitting layer 5 requires a large energy (460-480nm wavelength) to emit light, and the conjugation of the host material in the blue light-emitting layer 5 cannot be too long, and it is mainly anthracene derivatives. In addition, the thickness of the red light-emitting layer 5 may be greater than the thickness of the green light-emitting layer 5.

[0127] Taking a compound whose main material includes a structure as shown in Formula 1 as an example, where m is an integer greater than or equal to 1 in the structure shown in Formula 1, and the structure shown in Formula 1 can be:

[0128]

[0129] Where t is an integer greater than or equal to 0 and less than or equal to 4; X4 is independently selected from oxygen, sulfur, and... X5, X6, and X7 are each independently selected from oxygen, sulfur, and nitrogen; R4 is selected from hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; further, R4 may be selected from phenyl and biphenyl; Ar5 and Ar6 are each independently selected from hydrogen, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; further, Ar5 and Ar6 are each independently selected from phenyl and biphenyl; L6, L7, and L8 are each independently selected from single bonds, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl; ring B is selected from aromatic rings, fused aromatic rings, and fused heteroaromatic rings. The fused heteroaromatic ring may be indole, etc.

[0130] For example, the host material may include the following compounds:

[0131]

[0132]

[0133] The synthesis of the above compound T-3 is as follows:

[0134]

[0135] Intermediate 4, compound 13 (CAS: 1984-49-2), and compound 14 were dissolved in 100 ml of toluene solution in a molar ratio of 1 / 1 / 1. Nitrogen gas was purged three times. 10% tri-tert-butylphosphine solution and Pd2(dba)3 were rapidly added dropwise to the reaction flask, followed by the rapid addition of 2.9 g (30 mmol) sodium tert-butoxide. The mixture was heated under reflux for 12 h. After the reaction was completed, the reactants were poured into water, and the organic phase was extracted. The mixture was washed three times with water, dried over anhydrous sodium sulfate, filtered, and the organic solvent was evaporated by rotary evaporation to obtain the crude product. The crude product was passed through a silica gel column, recrystallized, and dried under vacuum to obtain compound T-3.

[0136] It should be noted that the aryl groups mentioned above can include monocyclic aryl groups and fused aryl groups. The heteroaryl groups mentioned above can include aromatic rings containing at least one heteroatom of O, N, or S, such as derivatives of dibenzofuran, dibenzothiophene, carbazole, oxazole, and azazine.

[0137] Taking a red light-emitting layer 5 in a light-emitting device as an example, at least two of the hole injection layer 2, the hole transport layer 3, the electron blocking layer 4, the electron injection layer 8, the electron transport layer 7, the hole blocking layer 6, and the light-emitting layer 5 include compounds having the structural formula shown in Formula 1. Taking a green light-emitting layer 5 in a light-emitting device as an example, at least two of the hole injection layer 2, the hole transport layer 3, the electron blocking layer 4, the electron injection layer 8, the electron transport layer 7, the hole blocking layer 6, and the light-emitting layer 5 include compounds having the structural formula shown in Formula 1. Taking a blue light-emitting layer 5 in a light-emitting device as an example, at least two of the hole injection layer 2, the hole transport layer 3, the electron injection layer 8, the electron transport layer 7, and the hole blocking layer 6 include compounds having the structural formula shown in Formula 1.

[0138] The anode 1 can include a material with a high work function. When used in a bottom-emitting structure, the anode 1 can be made of transparent oxides such as ITO or IZO, with a thickness of 80nm-200nm. When used in a top-emitting structure, the anode 1 can be a composite structure formed by a transparent oxide layer and a metal layer, such as "Ag / ITO" or "Ag / IZO". In the composite structure formed by the transparent oxide layer and the metal layer, the thickness of the metal layer can be 80nm-100nm, and the thickness of the metal oxide can be 5nm-10nm. Furthermore, the average reflectivity of the anode 1 in the visible light region can be 85%-95%.

[0139] The cathode 9 can include materials with low work function. Specific examples of cathode 9 materials include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, etc., and alloys thereof, such as Mg / Ag alloys. The thickness of the cathode 9 can be 10 nm to 30 nm. When the cathode 9 material is a Mg / Ag alloy, the Mg:Ag ratio is 3 / 7 to 1 / 9. Furthermore, the transmittance of the cathode 9 at a wavelength of 530 nm can be 50% to 60%.

[0140] This disclosure also provides a display module. The display module may include a substrate, a driving circuit layer, and a light-emitting device as described in any of the above embodiments. The light-emitting device may be disposed on one side of the driving circuit layer, for example, on the side of the driving circuit layer facing away from the substrate.

[0141] The display module may include multiple pixels. Each pixel may include three sub-pixels, such as a red sub-pixel, a green sub-pixel, and a blue sub-pixel. One light-emitting device constitutes one sub-pixel. In this disclosure, the light-emitting device constituting the red sub-pixel is referred to as the first light-emitting device, and the light-emitting layer 5 in the first light-emitting device is a red light-emitting layer 5. The light-emitting device constituting the green sub-pixel is referred to as the second light-emitting device, and the light-emitting layer 5 in the second light-emitting device is a green light-emitting layer 5. The light-emitting device constituting the blue sub-pixel is referred to as the third light-emitting device, and the light-emitting layer 5 in the third light-emitting device is a blue light-emitting layer 5.

[0142] The three electron blocking layers 4 in the first, second, and third light-emitting devices described above cannot simultaneously contain compounds having the structural formula shown in Formula 1. In one embodiment, the electron blocking layer 4 in the first light-emitting device contains a compound having the structural formula shown in Formula 1, while the electron blocking layers 4 in the second and third light-emitting devices do not contain compounds having the structural formula shown in Formula 1. In another embodiment, the electron blocking layer 4 in the second light-emitting device contains a compound having the structural formula shown in Formula 1, while the electron blocking layers 4 in the first and third light-emitting devices do not contain compounds having the structural formula shown in Formula 1. In other embodiments, the electron blocking layers 4 in both the first and second light-emitting devices contain compounds having the structural formula shown in Formula 1, while the electron blocking layer 4 in the third light-emitting device does not contain compounds having the structural formula shown in Formula 1. Furthermore, the thickness of the electron blocking layer 4 in the first light-emitting device is greater than the thickness of the electron blocking layer 4 in the second light-emitting device, and the thickness of the electron blocking layer 4 in the second light-emitting device is greater than the thickness of the electron blocking layer 4 in the third light-emitting device. The thickness of the electron blocking layer 4 in the first light-emitting device can be 500 angstroms to 900 angstroms. The thickness of the electron blocking layer 4 in the second light-emitting device can be 150 angstroms to 490 angstroms. The thickness of the electron blocking layer 4 in the third light-emitting device can be 20 angstroms to 140 angstroms.

[0143] The display module and the light-emitting device in this disclosure belong to the same inventive concept. The relevant details and beneficial effects can be referred to each other, and will not be repeated here.

[0144] The following are examples of the fabrication of the light-emitting device according to this embodiment.

[0145] Example 1 (Green Light-Emitting Device)

[0146] The pre-prepared ITO substrate is cleaned and dried. This ITO-coated glass plate serves as the anode 1 of the light-emitting device. A hole injection layer 2, a hole transport layer 3, an electron blocking layer 4, a light-emitting layer 5, a hole blocking layer 6, an electron transport layer 7, an electron injection layer 8, and a cathode 9 are sequentially deposited on one side of the anode 1. The hole injection layer 2 has a thickness of 10 nm and is composed of a mixture of compound HT-1 (see Table 1) and compound PD (see Table 1), with compound PD comprising 3% by mass. The hole transport layer 3 has a thickness of 100 nm and can be composed of compound HT-1 (see Table 1). The electron blocking layer 4 can have a thickness of 35 nm and can be composed of compound HT-2 (see Table 1). The light-emitting layer 5 has a thickness of 35 nm and is composed of a mixture of compound T-3, compound GH-2 (see Table 1), and compound GD (see Table 1), with compound GD comprising 10% by mass. The hole-blocking layer 6 can be 5 nm thick and made of compound E-3. The electron transport layer 7 can be 30 nm thick and is made of Liq (lithium 8-hydroxyquinoline) and compound ET-1 (see Table 1), with a deposition rate ratio of 1:1 between Liq and ET-1. The electron injection layer 8 can be 1 nm thick and is made of lanthanide metal Yb. The cathode 9 is a Mg / Ag electrode with a thickness of 13 nm.

[0147] Example 2 (Green Light-Emitting Device)

[0148] The light-emitting device was prepared using the same preparation method as in Example 1, except that the material of the light-emitting layer 5 included a mixture of compound T-7, compound GH-1 (see Table 1), and compound GD, and the mass fraction of compound GD in the mixture was 10%.

[0149] Comparative Example 1 (Green Light-Emitting Device)

[0150] The light-emitting device was prepared using the same preparation method as in Example 1, except that the material of the light-emitting layer 5 includes a mixture of compound GH-1, compound GH-2 and compound Ir(ppy)3 (see Table 1), and the mass fraction of compound Ir(ppy)3 in the mixture is 10%; the material of the hole blocking layer 6 can be compound TPBi.

[0151] Example 3 (Red Light-Emitting Device)

[0152] The light-emitting device was prepared using the same preparation method as in Example 1, except that the electron blocking layer 4 was made of the aforementioned compound H-5 and its thickness could be 60 nm; the light-emitting layer 5 had a thickness of 45 nm and its material could include a mixture of compound T-6 and compound Ir(dmpq)2acac, with the mass fraction of Ir(dmpq)2acac in the mixture being 10%; and the hole blocking layer 6 was made of TPBi.

[0153] Example 4 (Red Light-Emitting Device)

[0154] The light-emitting device was prepared using the same preparation method as in Example 3, except that the hole blocking layer 6 was made of compound E-3.

[0155] Example 5 (Red Light-Emitting Device)

[0156] The light-emitting device was prepared using the same method as in Example 3, except that the hole blocking layer 6 was made of compound HB-2 (see Table 1).

[0157] Comparative Example 2 (Red Light-Emitting Device)

[0158] The light-emitting device was prepared using the same preparation method as in Example 3, except that the material of the electron blocking layer 4 included compound HT-2 (see Table 1); the material of the light-emitting layer 5 included a mixture of compound RH (see Table 1) and compound Ir(dmpq)2acac, and the mass fraction of Ir(dmpq)2acac in the mixture was 10%.

[0159] Table 1

[0160]

[0161]

[0162]

[0163] The performance of the prepared light-emitting device was tested, and the results are shown in Table 2.

[0164] Table 2

[0165]

[0166] In Table 2, using the data from Comparative Example 1 as a reference, its voltage, efficiency, and lifetime data are set to 100%. Compared to Comparative Example 1, the light-emitting devices of Examples 1 and 2 have lower voltage, higher efficiency, and higher lifetime. Using the data from Comparative Example 2 as a reference, its voltage, efficiency, and lifetime data are set to 100%. Compared to Comparative Example 2, the light-emitting devices of Examples 3, 4, and 5 have lower voltage, higher efficiency, and higher lifetime. The hole-blocking layer 6 in Examples 4 and 5 uses different materials. The hole-blocking layer 6 in Example 5 includes HB-2, which is methylfluorene. Compared to adamantane fluorene, methylfluorene is less stable, resulting in a relatively lower device lifetime. Examples 4 and 3 both contain the same cycloalkylfluorene fragment, and their devices have good efficiency and lifetime because similar fragments form channels that facilitate electron-hole transitions.

[0167] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure in any way. Although this disclosure has been disclosed above with reference to a preferred embodiment, it is not intended to limit this disclosure. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this disclosure. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the content of the technical solution of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A light emitting device, characterized by, include: Anode and cathode arranged opposite each other; A light-emitting layer is disposed between the anode and the cathode; A hole transport structure is disposed between the anode and the light-emitting layer; An electron transport structure is disposed between the cathode and the light-emitting layer; The hole transport structure includes a hole transport material, which comprises the following compounds: Compound H-9.

2. The light emitting device of claim 1, wherein, The electron transport structure includes an electron transport material, which includes the following compounds: Compound E-7.

3. The light emitting device according to claim 1 or 2, characterized in that, The light-emitting layer comprises a host material and a dopant material, wherein the host material comprises the following compounds: Compound T-9.

4. The light emitting device of claim 2, wherein, The light-emitting layer is a blue light-emitting layer, and the hole transport structure includes: A hole injection layer is disposed on the side of the anode facing the light-emitting layer; A hole transport layer is disposed on the side of the hole injection layer facing the light-emitting layer; An electron blocking layer is disposed between the hole transport layer and the light-emitting layer; The electron transport structure includes: An electron injection layer is disposed on the side of the cathode facing the light-emitting layer; An electron transport layer is disposed on the side of the electron injection layer facing the light-emitting layer; A hole blocking layer is disposed on the side of the electron transport layer facing the light-emitting layer; Wherein, at least one of the hole injection layer and the hole transport layer includes the hole transport material, and at least one of the electron injection layer, the electron transport layer and the hole blocking layer includes the electron transport material.

5. The light emitting device of claim 3, wherein the first and second light emitting devices are arranged in a vertical direction. The light-emitting layer is a red light-emitting layer or a green light-emitting layer, and the hole transport structure includes: A hole injection layer is disposed on the side of the anode facing the light-emitting layer; A hole transport layer is disposed on the side of the hole injection layer facing the light-emitting layer; An electron blocking layer is disposed between the hole transport layer and the light-emitting layer; The electron transport structure includes: An electron injection layer is disposed on the side of the cathode facing the light-emitting layer; An electron transport layer is disposed on the side of the electron injection layer facing the light-emitting layer; A hole blocking layer is disposed on the side of the electron transport layer facing the light-emitting layer; Wherein, at least one of the hole injection layer, the hole transport layer, and the electron blocking layer includes the hole transport material, and at least one of the electron injection layer, the electron transport layer, and the hole blocking layer includes the electron transport material.

6. A display module, characterized by include: Substrate; A driving circuit layer is disposed on one side of the substrate; The light-emitting device according to any one of claims 1-5 is disposed on one side of the driving circuit layer.

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