Host compound for organic electroluminescent device

Abstract

The invention belongs to the technical field of organic light-emitting materials, and relates to a host compound for an organic light-emitting device. According to the compound provided by the invention, benzacridine imidazole or oxazole is used as a parent nucleus structure, and is connected with an amine derivative group with an electron donating characteristic to serve as a first light-emitting main body and a nitrogen-containing group with an electron withdrawing characteristic to serve as a second light-emitting main body respectively, so that the constructed compound has a proper triplet state energy value and a front track energy level. When the compound provided by the invention is used as a light-emitting host material, energy transfer between a host and an object can be ensured. Through further verification, the vibration of carbon-hydrogen bonds can be reduced by deuterating part of specific groups, so that the stability of the material is remarkably improved, and the luminous efficiency and the service life of the device are effectively improved by applying the deuterated compound to the organic electroluminescent device.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials and relates to a host compound for an organic electroluminescent device. Background Art

[0002] Organic electroluminescent devices (OLEDs) have been widely used in the fields of display and lighting due to their remarkable advantages such as high efficiency, low power consumption, high contrast ratio, thinness, light weight, and flexibility. Under the drive of an external electric field, the physical processes inside an OLED include: holes are injected from the anode into the organic light-emitting layer, and electrons are injected from the cathode into the organic light-emitting layer. When these injected holes and electrons meet in the organic light-emitting layer, the holes and electrons combine to form excitons. When the excitons transition back from the excited state to the ground state, energy is released, and the released energy is emitted outward in the form of light, thus achieving the light-emitting effect of the OLED.

[0003] Currently, organic electroluminescent devices have been applied to a certain extent in the industrial field. However, the devices generally have problems of low efficiency and short lifespan, and the factor of short lifespan is particularly fatal, seriously hindering their further application and promotion. To fabricate an OLED device with excellent performance, first, it is necessary to screen hole / electron transport materials with excellent mobility to ensure the carrier balance of electrons and holes in the light-emitting layer, thereby ensuring the efficient light emission of the OLED device; second, doping the light-emitting material in a suitable host material can effectively reduce the exciton quenching effect, and further improve the optoelectronic properties such as the efficiency, brightness, and lifespan of the OLED device. Doping the light-emitting material in a suitable host material. Thus, it can be seen that high-performance host materials are crucial for achieving high-quality OLED device performance.

[0004] For phosphorescent OLED devices, the selection of host materials is more stringent. The host material not only needs to have excellent carrier transport performance to ensure that holes and electrons can be efficiently injected into the light-emitting layer, but also needs to have a high triplet energy to avoid the occurrence of exciton energy back-transfer. However, how to develop a high-quality host material that not only meets the above stringent requirements but also has good stability has always been a difficult and hot issue to be overcome in the field of OLED technology. Although some host materials have been successfully developed and applied in OLED devices at present, there are still certain limitations in their performance and it is difficult to meet the growing demand of the market for higher-quality OLED devices. Therefore, developing a high-performance host material is of crucial significance for promoting the development of OLED technology towards higher quality. Summary of the Invention

[0005] In view of the above problems and deficiencies, the present invention provides a host compound for an organic light-emitting device. The compound of the present invention is based on benzacridine imidazole or oxazole as the mother nucleus and is obtained by modifying with different groups. This compound has appropriate frontier orbital energy levels and triplet energies and can be used as a red light host material in organic light-emitting devices, thereby improving the luminous efficiency and service life of the devices, etc.

[0006] In a first aspect, the present invention provides a compound comprising at least one of a first host compound and a second host compound; the first host compound has a structure shown in Formula 1, and the second host compound has a structure shown in Formula 2, , ; wherein X and Y in Formula 1 or Formula 2 are each independently selected from one of N(Ar3) and O, but at least one of X and Y is N(Ar3); n in Formula 1 or m in Formula 2 are each independently selected from the integers 1 and 2; L1 in Formula 1 is a bridging group, and L2 in Formula 2 is a single bond or a bridging group; The L1 bridging group and the L2 bridging group are each selected from one of phenyl, biphenyl, and naphthyl; Z1, Z2, Z3, Z4, and Z5 in Formula 2 are each independently selected from one of C and N, and at most three of Z1, Z2, Z3, Z4, and Z5 are N; When there are two adjacent Cs in Z1, Z2, Z3, Z4, and Z5 in Formula 2, they form a ring with the adjacent R6; R6 in Formula 2 is selected from one of a substituted or unsubstituted C1-C10 alkane, a substituted or unsubstituted C1-C10 alkene, a C6-C30 aryl, and a heteroaryl containing N or O heteroatoms and having a carbon number of C3-C30, and the substituent is an alkane, an alkene, or an aryl; Ar1, Ar2 in Formula 1, and Ar3 in N(Ar3) are each independently selected from one of a C6-C30 aryl and a heteroaryl containing N or O heteroatoms and having a carbon number of C3-C30; Ar1 and Ar2 in Formula 1 are the same or different; when m = 2 in Formula 2, R6 are the same or different; R1, R2, R3, R4, R5 in Formula 1 or R1, R2, R3, R4, R5 in Formula 2 are hydrogen or deuterium; Ar1 and Ar2 in Formula 1 are each independently selected from one or more of phenyl, naphthyl, biphenyl, dibenzofuranyl, 9,9-dimethylfluorenyl, and N-phenylcarbazolyl; The adjacent atoms between Ar1 and Ar2 in Formula 1 are bonded into a carbazole ring or a condensed carbazole ring in the form of a single bond; For Ar1 and Ar2 in Formula 1, Ar3 in N(Ar3), and the hydrogen atom on R6 in Formula 2, all can be deuterated.

[0007] Preferably, in the compound provided by the present invention, Ar3 in N(Ar3) is selected from one or more of phenyl, naphthyl, and biphenyl.

[0008] Preferably, in the compound provided by the present invention, R6 in Formula 2 is selected from one or more of phenyl, naphthyl, biphenyl, pyridine, pyrazine, pyridazine, and pyrimidine.

[0009] Furthermore, in the compound provided by the present invention, the first host compound has structures shown in Formulas 3 to 6,

[0010] ;

[0011] Furthermore, in the compound provided by the present invention, the second host compound has structures shown in Formulas 7 to 10,

[0012] ;

[0013] Furthermore, in the compound provided by the present invention, the structure of the first host compound is as shown below,

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] 。

[0038] Furthermore, in the compound provided by the present invention, the structure of the second host compound is as follows:

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] 。

[0059] In a second aspect, the present invention provides an application of the above compound in an organic electroluminescent device.

[0060] In a third aspect, the present invention provides an organic electroluminescent device, comprising an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer. The organic thin film layer includes a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and the light-emitting layer contains the above compound.

[0061] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: The present invention uses benzoacridine imidazole or oxazole as the parent nucleus, and connects an amine-derived group with electron-donating characteristics as the first light-emitting host, and connects a nitrogen-containing group with electron-withdrawing characteristics as the second light-emitting host. The newly constructed compound has appropriate triplet energy values and frontier orbital energy levels. When the compound provided by the present invention is used as a light-emitting host material, the energy transfer between the host and the guest can be ensured. Through further research, it is found that deuterating some groups in the compound significantly reduces the vibration of carbon-hydrogen bonds and significantly improves the stability of the material. Applying the deuterated compound as the host material of the light-emitting layer in an organic electroluminescent device effectively improves the luminous efficiency and lifespan of the device. Description of the Drawings

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0063] Figure 1 It is a schematic structural diagram of an organic electroluminescent element. Among them, 1 is a substrate, 2 is an anode layer, 3 is a hole injection layer, 4 is a first hole transport layer, 5 is a second hole transport layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, and 10 is a cathode layer. Detailed implementation manners

[0064] Next, the technical solutions of the present invention will be described in conjunction with embodiments. However, the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified. The percentages in the following embodiments are all mass percentages unless otherwise specified.

[0065] Preparation examples This preparation example provides the synthesis methods of some intermediates and compounds. The synthesis methods of the remaining intermediates and compounds are all similar methods and can be easily synthesized. The specific synthesis routes are as follows.

[0066] Synthesis of intermediate 1:

[0067] Synthesis of intermediate 1-1: Under nitrogen protection, add raw material 1 (348 g, 1 mol), raw material 2 (217 g, 1 mol), Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium, 23 g, 0.02 mol), K2CO3 (potassium carbonate, 276 g, 2 mol), TBAB (tetrabutylammonium bromide, 32 g, 0.1 mol), toluene (2000 mL), ethanol (1000 mL), and water (500 mL) into a three-necked flask. Heat to 76 °C and stir for 8 h, then cool to room temperature. Wash with water until neutral. Dry the organic phase with anhydrous magnesium sulfate, then pass through a silica gel column, and recrystallize and purify with a toluene / ethanol mixed solvent to obtain 330 g of intermediate 1-1 with a yield of 70%.

[0068] Synthesis of Intermediate 1: Under nitrogen protection, add Intermediate 1-1 (220 g, 0.5 mol), PPh3 (triphenylphosphine, 262 g, 1 mol), and o-dichlorobenzene (1000 mL) to a three-necked flask, stir and heat to 160 °C for reaction for 18 h. After cooling the reaction solution to room temperature, add n-heptane to precipitate the solid product. After filtration, recrystallize and purify with toluene to obtain 135 g of Intermediate 1, with a yield of 66%.

[0069] Synthesis of Intermediate 2:

[0070] The synthesis of Intermediate 2-1 refers to the synthesis of Intermediate 1-1, and replace Raw Material 1 with Raw Material 3; The synthesis of Intermediate 2 refers to the synthesis of Intermediate 1, and replace Intermediate 1-1 with Intermediate 2-1.

[0071] Synthesis of Intermediate 3:

[0072] Synthesis of Intermediate 3-1: Under nitrogen protection, add Raw Material 4 (273 g, 1 mol), Raw Material 2 (217 g, 1 mol), Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium, 23 g, 0.02 mol), K2CO3 (potassium carbonate, 276 g, 2 mol), TBAB (tetrabutylammonium bromide, 32 g, 0.1 mol), toluene (2000 mL), ethanol (1000 mL), and water (500 mL) to a three-necked flask, heat to 76 °C, stir and react for 6 h, then cool to room temperature, wash with water until neutral, dry the organic phase with anhydrous magnesium sulfate, filter through a silica gel column, and then recrystallize and purify with a toluene / n-heptane mixed solvent to obtain 304 g of Intermediate 3-1, with a yield of 83%.

[0073] Synthesis of Intermediate 3: Under nitrogen protection, add Intermediate 3-1 (183 g, 0.5 mol), PPh3 (triphenylphosphine, 262 g, 1 mol), and o-dichlorobenzene (1000 mL) to a three-necked flask, stir and heat to 160 °C for reaction for 14 h. After cooling the reaction solution to room temperature, add n-heptane to precipitate the solid product. After filtration, recrystallize and purify with a toluene / ethanol mixed solvent to obtain 112 g of Intermediate 3, with a yield of 67%.

[0074] Synthesis of Intermediate 4:

[0075] The synthesis of Intermediate 4-1 refers to the synthesis of Intermediate 3-1, and replace Raw Material 4 with Raw Material 5; The synthesis of Intermediate 4 refers to the synthesis of Intermediate 3, and replace Intermediate 3-1 with Intermediate 4-1.

[0076] Synthesis of Intermediate 5:

[0077]

[0078] Synthesis of Intermediate A-1: Under nitrogen protection, add raw material A-1 (187 g, 1 mol), pyridine (158 g, 2 mol), and tetrahydrofuran (800 mL) into a three-necked flask. After stirring and dissolving, add raw material A-2 (140 g, 1 mol) into the system in three batches under an ice bath. Continue stirring for 30 min, and then raise the temperature to room temperature and continue the reaction for 3 h. Add dichloroethane (200 mL), wash repeatedly with water, separate the organic phase, dry it with anhydrous magnesium sulfate, filter, concentrate the filtrate, and recrystallize it with n-heptane to obtain 224 g of white solid Intermediate A-1 with a yield of 77%.

[0079] Synthesis of Intermediate A: Under nitrogen protection, add Intermediate A-1 (146 g, 0.5 mol), TsOH (p-toluenesulfonic acid, 172 g, 1 mol), and toluene (800 mL) into a three-necked flask. After stirring evenly, heat the system to 108 °C and react for 3 h. After the reaction solution is cooled to room temperature, wash it with water, dry the organic phase with anhydrous magnesium sulfate, filter, pass the filtrate through a silica gel column, concentrate the column liquid, and recrystallize and purify it with a mixed solvent of toluene / ethanol to obtain 87 g of Intermediate A with a yield of 64%.

[0080] For the synthesis of Intermediate 5-1, refer to the synthesis method of Intermediate 3-1, and replace raw material 4 with Intermediate A.

[0081] For the synthesis of Intermediate 5, refer to the synthesis method of Intermediate 3, and replace Intermediate 3-1 with Intermediate 5-1.

[0082] Synthesis of Intermediate B:

[0083] For the synthesis of Intermediate B-1, refer to the synthesis of Intermediate A-1, and replace raw material A-1 with raw material B-1; For the synthesis of Intermediate B, refer to the synthesis of Intermediate A, and replace Intermediate A-1 with Intermediate B-1.

[0084] Synthesis of Intermediate C:

[0085] Synthesis of intermediate C-1: Under argon protection, add raw material C-2 (98g, 1mol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 9g, 10mmol), P(t-Bu)3 (tri-tert-butylphosphine, 4g, 20mmol), sodium tert-butoxide (192g, 2mol), toluene (800mL) to a three-necked flask, stir and heat to 110°C reflux, add raw material C-1 (279g, 1mol) in 4 portions, and continue to react for 2h. After the reaction is complete, cool to room temperature, wash with water until neutral, dry the organic phase with anhydrous magnesium sulfate and filter, pass the filtrate through a silica gel column, concentrate the column liquid and purify it by recrystallization with toluene to obtain 217g of intermediate C-1, HPLC=97.8941%, yield 73%.

[0086] Synthesis of intermediate C-2: Under nitrogen protection, add intermediate C-1 (146 g, 0.5 mol) and dry tetrahydrofuran (600 mL) to a three-necked flask, add Pd / C (14.6 g) while stirring the system, slowly add hydrazine hydrate, slowly raise the temperature to 50 ° C and react for 10 hours. After the reaction is completed, cool to room temperature, add saturated sodium bicarbonate solution to terminate the reaction, add dichloroethane (500 mL) for extraction, dry the organic phase and pass it through a silica gel column, concentrate the column liquid and recrystallize it with n-heptane, purify it to obtain 91.7 g of intermediate C-2, with a yield of 70%.

[0087] Synthesis of intermediate C: Under nitrogen protection, add intermediate C-2 (52g, 0.2mol), benzaldehyde (21g, 0.2mol), and DMF (200mL) to a three-necked flask, stir and dissolve at room temperature, then add Na2S2O5 (38g, 0.2mol) three times, and continue stirring and reacting for 8h. Add dichloroethane (600mL), wash repeatedly with water, dry the organic phase with anhydrous magnesium sulfate, filter and concentrate, and recrystallize with toluene to obtain 41g of intermediate C with a yield of 60%.

[0088] Synthesis of intermediate D:

[0089] The synthesis of intermediate D-1 refers to the synthesis of intermediate C-1, except that raw materials C-1 and C-2 are replaced by raw materials D-1 and D-2; The synthesis of intermediate D-2 refers to the synthesis of intermediate C-2, except that intermediate C-1 is replaced by intermediate D-1; The synthesis of intermediate D refers to the synthesis of intermediate C, except that intermediate C-2 is replaced by intermediate D-2.

[0090] Referring to the synthesis methods of intermediates 1 to 5, other intermediates can be synthesized. The only difference is that the corresponding intermediates need to be used to replace the products, and the mass amount of the intermediates is changed according to the molar amount, as shown below:

[0091] Synthesis of compound 1-1:

[0092] Under nitrogen protection, intermediate 1 (40.9 g, 0.1 mol), raw material 1-1 (32.3 g, 0.1 mol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 0.9 g, 1 mmol), P(t-Bu)3 (tri-tert-butylphosphine, 0.4 g, 2 mmol), sodium tert-butoxide (19.2 g, 0.2 mol), toluene (300 mL) were added to a three-necked flask, stirred and heated to 110°C for reflux reaction for 2 h. After the reaction was complete, it was cooled to room temperature and washed with water until neutral. The organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was passed through a silica gel column. After the column liquid was concentrated, it was recrystallized and purified with toluene and dried. It was sublimed under high vacuum at 290°C to obtain 35.8 g of white crystalline compound 1-1, HPLC=99.9877%, yield 55%, LC-MS: m / z 652.2627 [M+].

[0093] Synthesis of compound 1-22:

[0094]

[0095] The synthesis of intermediate a-1 and intermediate 13 were both based on the synthesis method of compound 1-1, with only the corresponding reactants being replaced.

[0096] The synthesis of compound 1-22 was prepared by referring to the synthesis method of compound 1-1, except that intermediate 1 and raw material 1-1 were replaced by intermediate 7 and intermediate 13. After synthesis and purification, white crystalline compound 1-22 was obtained by high vacuum sublimation at 310°C, HPLC = 99.9791%, yield 51%, LC-MS: m / z 742.2570 [M+].

[0097] Synthesis of compound 1-66:

[0098] The synthesis of compound 1-66 was prepared by referring to the synthesis method of compound 1-1, except that intermediate 1 and raw material 1-1 were replaced by intermediate 5 and raw material 1-3. After synthesis and purification, light yellow crystalline compound 1-66 was obtained by high vacuum sublimation at 300°C, HPLC = 99.9925%, yield 59%, LC-MS: m / z 653.2256 [M+].

[0099] Synthesis of compound 2-7:

[0100] The synthesis method of Intermediate 14 refers to the synthesis of Intermediate 3-1, only replacing the corresponding reactant raw materials.

[0101] Synthesis of Compound 2-7: Under nitrogen protection, add Intermediate 1 (40.9 g, 0.1 mol), Intermediate 14 (46.3 g, 0.1 mol), Pd2(dba)3 (tris(dibenzylideneacetone)dipalladium, 0.9 g, 1 mmol), P(t-Bu)3 (tri-tert-butylphosphine, 0.4 g, 2 mmol), sodium tert-butoxide (19.2 g, 0.2 mol), and toluene (400 mL) to a three-necked flask. Stir and heat to reflux at 110 °C for 3 h. After the reaction is complete, cool to room temperature, wash with water until neutral, dry the organic phase with anhydrous magnesium sulfate and filter. The filtrate is passed through a silica gel column, the column liquid is concentrated, recrystallized and purified with THF solvent, and dried. It is sublimated under high vacuum at 320 °C to obtain a white molten solid Compound 2-7, HPLC = 99.9912%, yield 47%, LC-MS: m / z 792.3001 [M+].

[0102] Synthesis of Compound 2-35:

[0103] The synthesis of Compound 2-35 refers to the synthesis method of Compound 2-7. Replace Intermediate 1 and Intermediate 14 with Intermediate 2 and Raw Material 1-5. After synthesis and purification, it is sublimated under high vacuum at 315 °C to obtain a white crystal Compound 2-35, HPLC = 99.9836%, yield 60%, LC-MS: m / z 613.2266 [M+].

[0104] Synthesis of Compound 2-66:

[0105] The synthesis of Intermediate 15 refers to the synthesis of Intermediate 3-1, only replacing the corresponding reactant raw materials.

[0106] The synthesis of Compound 2-66 refers to the synthesis method of Compound 2-7. Replace Intermediate 1 and Intermediate 14 with Intermediate 6 and Intermediate 15. After synthesis and purification, it is sublimated under high vacuum at 320 °C to obtain a light yellow molten solid Compound 2-66, HPLC = 99.9818%, yield 58%, LC-MS: m / z 690.2208 [M+].

[0107] Referring to the synthesis methods of the above compounds, all the compounds in the present invention can be synthesized. The difference is only that according to the different products, different intermediates need to be used for replacement, and the mass dosage of the intermediate is changed according to the different molar amounts.

[0108] The performance parameters (including HOMO energy level, LUMO energy level, and triplet energy T1) of some compounds synthesized in the present invention and the existing OLED materials RH1 and RH2 were measured, and the results are shown in Table 1.

[0109] Table 1 Measurement results of the performance parameters of the compounds and existing materials

[0110] Note: The data of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and the triplet energy T1 were all obtained by simulation calculation using Gaussian 09 software. The calculation method used the B3LYP hybrid functional and the basis set 6-31g(d).

[0111] As can be seen from Table 1, the compounds provided by the present invention have appropriate triplet energy, HOMO energy level, and LUMO energy level, which are beneficial to the carrier transport and the energy transfer between the host and the guest in the OLED device. The compounds of the present invention are suitable as the light-emitting host material in the OLED device.

[0112] Taking some compounds provided by the present invention as examples below, they were applied as the light-emitting host material to the organic electroluminescent device to verify the excellent effects achieved.

[0113] Specifically, the excellent effects of the OLED materials of the present invention applied in the device were described in detail through the device performance of Device Examples 1-30 and Comparative Examples. The structure manufacturing processes of Device Examples 1-30 and Comparative Examples of the present invention were exactly the same, and the same glass substrate and electrode materials were used, and the film thickness of the electrode materials was also kept consistent. The difference was that the light-emitting layer host material was adjusted, as follows.

[0114] Comparative Example This comparative example provides an organic electroluminescent device, and its structure is specifically as Figure 1 shown, including a substrate 1, an anode layer 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, and a cathode layer 10 which are stacked in sequence.

[0115] Among them, the substrate 1 is a glass substrate with a thickness of 0.7 mm. The material of the anode layer 2 is indium tin oxide (ITO) with a high work function. The material of the hole injection layer 3 is HAT-CN with a thickness of 5 nm; the material of the first hole transport layer 4 is HT1 with a thickness of 60 nm; the material of the second hole transport layer 5 is HT2 with a thickness of 15 nm; the light-emitting layer 6 uses the first host material RH1 doped with the second host material RH2 as the mixed host material, and the mass percentage of RH1 to RH2 is 47.5%:47.5%. RD01 is used as the light-emitting material with a doping mass percentage of 5%, and the thickness of the light-emitting layer is 30 nm; the material of the hole blocking layer 7 is HB1 with a thickness of 10 nm; the material of the electron transport layer 8 is ET1 with a thickness of 30 nm; the material of the electron injection layer 9 is Liq with a thickness of 2 nm; the material of the cathode layer is Al with a thickness of 100 nm.

[0116] The basic material structural formulas used in each functional layer of the comparative organic electroluminescent device are as follows:

[0117]

[0118] The specific preparation steps of the comparative organic electroluminescent device are as follows: (1) Clean the ITO anode on the transparent glass or plastic substrate, ultrasonically clean it with deionized water, acetone, and ethanol for 20 min each, and then perform plasma treatment in an oxygen atmosphere for 5 min; (2) On the ITO anode layer, deposit the hole injection layer material HAT-CN with a thickness of 5 nm by vacuum evaporation, and this layer serves as the hole injection layer; (3) Deposit the first hole transport material HT1 with a thickness of 60 nm on the hole injection layer by vacuum evaporation, and this layer serves as the first hole transport layer; (4) Deposit the second hole transport material HT2 with a thickness of 15 nm on the first hole transport layer HT1 by vacuum evaporation, and this layer serves as the second hole transport layer; (5) On the second hole transport layer, deposit the light-emitting layer by triple-source co-evaporation. Use RH1 as the first host material and RH2 as the second host material, and the mass percentage of RH1 to RH2 is 47.5%:47.5% as the mixed host material. The mixed host material and the light-emitting material RD01 are co-evaporated simultaneously, and the doping mass ratio of RD01 is 5%, and the thickness of the light-emitting layer is 30 nm; (6) On the light-emitting layer, deposit the hole blocking material HB1 with a thickness of 10 nm by vacuum evaporation, and this layer serves as the hole blocking layer; (7) On the hole blocking layer, an electron transport material ET1 is deposited by vacuum evaporation with a thickness of 30 nm, and this layer serves as the electron transport layer. (8) On the electron transport layer, an electron injection material Liq is deposited by vacuum evaporation with a thickness of 2 nm, and this layer serves as the electron injection layer. (9) On the electron injection layer, a cathode Al is deposited by vacuum evaporation with a thickness of 100 nm. This layer is used as the cathode conductive electrode, and this layer is the cathode layer.

[0119] The implementation processes of Examples 1 to 30 are the same as that of Comparative Example 1, except that the compound 1-1, compound 1-14, compound 1-22, compound 1-27, compound 1-37, compound 1-48, compound 1-53, compound 1-66, compound 1-82, compound 1-87, and compound 1-94 provided by the present invention are used to replace the first host material RH1, and the compound 2-1, compound 2-7, compound 2-9, compound 2-21, compound 2-27, compound 2-35, compound 2-53, compound 2-66, compound 2-69, compound 2-75, and compound 2-84 are used to replace the second host material RH2.

[0120] The cathodes and anodes of the organic electroluminescent devices of Examples 1 to 30 and the comparative example are connected by a known driving circuit, and the voltage-efficiency-current density relationship of the OLED devices is tested by using a Keithley 2400 power supply combined with a PR670 photometer by a standard method; the lifetime of the red light device is tested by the constant current method, and the test conditions are that under a constant current density of 20 mA / cm 2 When the initial brightness of the device is 100% under a constant current density, the time required for the brightness to decay to 95% of the initial brightness is the LT95 lifetime of the device; the light-emitting layer compositions and test results of Examples 1 to 30 of the device are shown in Table 2, and the test data are relative values (%).

[0121] Table 2 Performance test results of organic electroluminescent devices of each example

[0122] As can be seen from Table 1, when the compound prepared by the present invention is used as a red light host material in an OLED device, the performance is better than that of existing OLED devices. The luminous efficiency is increased by 15-56%, and the device lifetime is extended by 19-60%. For example, in Example 5, when the partially deuterated compound 1-37 is used as the first red light host material, compared with the comparative example, both the luminous efficiency and the service life are significantly improved. The luminous efficiency is increased by 41%, and the device lifetime is increased by 53%. In Example 19, when the partially deuterated compound 2-66 is used as the second red light host material, compared with the comparative example, the device luminous efficiency is increased by 44%, and the device lifetime is increased by 47%. In Example 25, when the partially deuterated compound 1-37 and the partially deuterated compound 2-84 are used as the first red light host material and the second red light host material respectively, compared with the comparative example, the luminous efficiency is increased by 56%, and the device lifetime is increased by 60%. When the compound of the present invention is used as the red light emitting layer host material in an OLED device, compared with the existing material devices, the luminous efficiency and the lifetime performance are greatly improved, and it has great application value in the application of OLED devices and has good industrialization prospects.

[0123] As described above, the basic principle, main features and advantages of the present invention are preferably described. The above embodiments and the description are only descriptions of the preferred embodiments of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the present invention.

Claims

1. A compound, characterized in that, Comprising at least one of a first host compound and a second host compound; The first host compound has a structure shown in Formula 1, and the second host compound has a structure shown in Formula 2, ， ； wherein X and Y in Formula 1 or Formula 2 are each independently selected from one of N(Ar3) and O, but at least one of X and Y is N(Ar3); n in Formula 1 or m in Formula 2 are each independently selected from the integers 1 and 2; L1 in Formula 1 is a bridging group, and L2 in Formula 2 is a single bond or a bridging group; The L1 bridging group and the L2 bridging group are each independently selected from one of phenyl, biphenyl, and naphthyl; Z1, Z2, Z3, Z4, and Z5 in Formula 2 are each independently selected from one of C and N, and at most three of Z1, Z2, Z3, Z4, and Z5 are N; When there are two adjacent Cs in Z1, Z2, Z3, Z4, and Z5 in Formula 2, they form a ring with adjacent R6; R6 in Formula 2 is selected from one of a substituted or unsubstituted C1-C10 alkane, a substituted or unsubstituted C1-C10 alkene, a C6-C30 aryl, and a heteroaryl containing N or O heteroatoms and having a carbon number of C3-C30, and the substituent is an alkane, an alkene, or an aryl; Ar1, Ar2 in Formula 1, and Ar3 in N(Ar3) are each independently selected from one of a C6-C30 aryl and a heteroaryl containing N or O heteroatoms and having a carbon number of C3-C30; Ar1 and Ar2 in Formula 1 are the same or different; when m = 2 in Formula 2, R6 are the same or different; R1, R2, R3, R4, R5 in Formula 1 or R1, R2, R3, R4, R5 in Formula 2 are hydrogen or deuterium; Ar1 and Ar2 in Formula 1 are each independently selected from one or more of phenyl, naphthyl, biphenyl, dibenzofuranyl, 9,9-dimethylfluorenyl, and N-phenylcarbazolyl; The adjacent atoms between Ar1 and Ar2 in Formula 1 are bonded to form a carbazole ring or a carbazole fused ring in a single bond form; The hydrogen atoms on Ar1, Ar2 in Formula 1, Ar3 in N(Ar3), and R6 in Formula 2 can all be deuterated.

2. The compound according to claim 1, wherein The first host compound has a structure shown in Formulas 3 to 6, 。 3. The compound according to claim 1, wherein The second host compound has a structure shown in Formulas 7 to 10, 。 4. The compound according to claim 1, wherein The structure of the first host compound is shown as follows, 。 5. The compound according to claim 1, characterized in that, The structure of the second host compound is shown as follows, 。 6. Use of the compound according to any one of claims 1 to 5 in an organic electroluminescent device.

7. An organic electroluminescent device, comprising an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer, wherein the organic thin film layer includes a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, characterized in that, The light-emitting layer contains the compound according to any one of claims 1 to 5.

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