An organic compound for a double light-emitting layer blue light-emitting device and a double light-emitting layer blue organic electroluminescent device comprising the same

Abstract

The application belongs to the technical field of OLED and specifically comprises an organic compound for a double light-emitting layer blue light device and a double light-emitting layer blue light organic electroluminescent device comprising the same. The structural general formula of the organic compound is shown in the following. By introducing a triphenyleno[1,12-bcd]furan group on a benzanthracene nucleus, the benzanthracene nucleus has a rigid planar structure, weak electron-withdrawing ability, and excellent thermal stability and chemical stability. In addition, the triphenylene skeleton also has an energy level structure suitable for a multi-channel high-energy level reverse intersystem crossing process. After connecting the triphenyleno[1,12-bcd]furan structure and the benzanthracene nucleus directly, the HOMO and LUMO energy levels of the material can be regulated, the carrier injection barrier is reduced, and the prepared double light-emitting layer device has a significant improvement in voltage, efficiency and lifetime.I.

Description

Technical Field

[0001] The present invention belongs to the technical field of OLEDs, and specifically includes an organic compound for a double-emitting layer blue-light device and a double-emitting layer blue-light organic electroluminescent device containing the same. Background Art

[0002] In recent years, in order to improve the device performance of blue OLEDs, a double-emitting layer device architecture has been proposed. This architecture uses two adjacent emitting layers with different host triplet energy levels, and by means of Dexter energy transfer, separates the "carrier recombination process" and the "triplet-triplet fusion process" that conventionally occur in a single emitting layer into two adjacent emitting layers, thereby significantly reducing the quenching of carriers and excitons, singlet excitons and triplet excitons, and achieving a significant efficiency improvement; however, such devices still have the following technical problems to be solved urgently: 1. The voltage of double-emitting layer devices is usually higher than that of traditional single-emitting layer devices. On the one hand, the device structure of double-emitting layer devices is more complex than that of single-emitting layer devices. While increasing the film layers, the interface barrier and the transport characteristics of the new film layers will change. On the other hand, the HOMO energy level of the common parent nucleus of the host material in the first emitting layer, such as benzanthracene, is deeper than that of the anthracene-based parent nucleus, increasing the difficulty of hole injection. The superposition of these factors makes it difficult to reduce the voltage of double-emitting layer devices; 2. By separating the recombination region (closer to the anode, also called the first emitting layer) and the triplet fusion region (denoted as the TTF region, closer to the cathode, also called the second emitting layer), double-emitting layer devices reduce the quenching process of triplet excitons and improve the quantum efficiency. However, limited by the TTF mechanism and the energy level relationship of most materials (2×T1<T2), the internal quantum efficiency is difficult to exceed 40%. Especially in the recombination region, the host material mainly plays the role of recombining to generate singlet and triplet excitons, and the generated triplet excitons need to be transferred to the TTF region to undergo the TTF process. Since the transfer of triplet excitons relies on the short-range Dexter energy transfer process, in the actual light-emitting process, since the triplet excitons generated by recombination need to undergo multiple Dexter energy transfers to reach the TTF region, there are still some triplet excitons that cannot be transferred to the TTF region in time. Therefore, how to make full use of the triplet excitons in the recombination region that have not been transferred to the TTF region to improve the device efficiency is an urgent problem to be solved for double-emitting layer devices. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the present invention provides an organic compound for a double-emitting layer blue-light device and a double-emitting layer blue-light organic electroluminescent device containing the same.

[0004] To achieve the above objectives, the technical solutions adopted by the present invention include: A first aspect of the present invention provides an organic compound for use in a dual-emitting-layer blue light device, the general structural formula of which is shown below: I; Ar1, Ar2, and Ar3 may be the same or different, and each is independently selected from one of hydrogen, deuterated or non-deuterated phenyl, deuterated or non-deuterated naphthyl, phenanthryl, deuterated or non-deuterated trefyl, deuterated or non-deuterated pyrene, deuterated or non-deuterated benzophenanthryl, deuterated or non-deuterated tribenzo[1,12-bcd]furanyl, and at least one is selected from tribenzo[1,12-bcd]furanyl; In Formula I, any hydrogen atom can be replaced by deuterium.

[0005] Furthermore, the tribenzo[1,12-bcd]furanyl group is selected from one of the following structures: , , , , ; “ " indicates a connection key.

[0006] Furthermore, Ar1, Ar2, and Ar3 are not hydrogen, meaning that Ar1, Ar2, and Ar3 can be one of phenyl, naphthyl, phenanthryl, trefyl, pyrene, or triphenyl[1,12-bcd]furanyl.

[0007] Furthermore, only one of Ar2 and Ar3 is hydrogen, which means that Ar2 is not hydrogen and Ar3 is hydrogen, or Ar3 is not hydrogen and Ar2 is hydrogen.

[0008] Furthermore, since Ar2 and Ar3 are both hydrogen, Ar1 must be tribenzo[1,12-bcd]furanyl.

[0009] Furthermore, Ar1 is tribenzo[1,12-bcd]furanyl.

[0010] Furthermore, the Ar3 is selected from hydrogen, deuterated or non-deuterated phenyl, and deuterated or non-deuterated tribenzo[1,12-bcd]furanyl.

[0011] Furthermore, the organic compound is selected from the structures shown below:

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[0053] .

[0054] A second aspect of the present invention provides a dual-emitting-layer blue organic electroluminescent device, comprising an anode, a hole transport region, a first emitting layer, a second emitting layer, an electron transport region, and a cathode sequentially disposed on a substrate; wherein the first emitting layer comprises the organic compound described above.

[0055] Furthermore, the first light-emitting layer includes a first host material and a first guest material, wherein the first host material is selected from the organic compounds described above.

[0056] Beneficial effects of this invention: This invention introduces a tribenzo[1,12-bcd]furan group onto the benzo[anthracene] core, giving it a rigid planar structure, weak electron-withdrawing ability, and excellent thermal and chemical stability. In addition, the tribenzo[1,12-bcd]furan group also has a large T1 energy level. Directly connecting the tribenzo[1,12-bcd]furan group to the benzo[anthracene] core can maintain the material with a high T1 energy level to achieve a dual-emitting-layer mechanism, and can also tune the HOMO and LUMO energy levels of the material to reduce the carrier injection barrier. Ultimately, the fabricated dual-emitting-layer device shows significant improvements in voltage, efficiency, and lifetime. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device of the present invention, wherein 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-electron blocking layer, 6-first light-emitting layer, 7-second light-emitting layer, 8-hole blocking layer, 9-electron transport layer, 10-electron injection layer, 11-cathode, and 12-capping layer. Detailed Implementation

[0058] To better understand the content of this invention, it will be described in detail with reference to the accompanying drawings and embodiments.

[0059] The compounds of this invention are applicable to light-emitting elements, display panels, and electronic devices, particularly organic electroluminescent devices. The electronic devices described in this invention are devices comprising a layer of at least one organic compound, and may also comprise layers of inorganic materials or layers formed entirely of inorganic materials. Preferably, the electronic devices are organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic dye-sensitized solar cells (O-DSSCs), organic optical detectors, organic photosensors, organic field quenching devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), and organic plasma emitting devices. Organic electroluminescent devices (OLEDs) are particularly preferred. A schematic diagram of an exemplary organic electroluminescent device is shown below. Figure 1 As shown.

[0060] Experimental Section To better understand the content of this invention, the polycyclic compound, the preparation method of the compound, and the luminescent properties of the device will be explained in detail with reference to embodiments. Various chemical reactions can be applied to the synthesis method of the compound according to one embodiment of this invention. However, it should be noted that the synthesis method of the compound according to one embodiment of this invention is not limited to the synthesis method described below. Unless otherwise stated, subsequent synthesis is carried out in an anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0061] intermediate synthesis Example 1 of intermediate synthesis

[0062] In a 1L three-necked flask, under nitrogen protection, 200mL of toluene, 100mL of ethanol, and 100mL of water were added. Then, compound E1 (12.28g, 40mmol), compound F1 (4.88g, 40mmol), potassium carbonate (16.60g, 120mmol), and tetraphenylphosphine palladium (1.4g, 1.2mmol) were added. The mixture was heated to 80℃ and reacted for 12h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was dissolved in toluene and filtered to remove the solid insoluble matter. The product G1 was then recrystallized to give 10.70g, yield: 88%, MS (m / z) (M+): 304.

[0063] In a 500 mL three-necked flask, intermediate compound G1 (9.12 g, 30 mmol) was stirred with 200 mL of N,N-dimethylformamide. N-bromosuccinimide (6.42 g, 36 mmol) was added at room temperature, and the mixture was stirred for 8 hours. Methanol was added to the reaction solution, and the resulting yellow solid was filtered. The solid was recrystallized from toluene and dried under vacuum to give product H1: 9.74 g, yield: 85%, MS (m / z) (M+): 382.

[0064] In a 500 mL three-necked flask, under nitrogen protection, 125 mL of toluene, 80 mL of ethanol, and 80 mL of water were added. Then, compound H1 (9.58 g, 25 mmol), compound K1 (7.38 g, 25 mmol), potassium carbonate (10.38 g, 75 mmol), and tetraphenylphosphine palladium (0.88 g, 0.75 mmol) were added. The mixture was heated to 80 °C and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was dissolved in toluene and filtered to remove the solid insoluble matter. The product L1 was then recrystallized to give 11.06 g, yield: 80%, MS (m / z) (M+): 553.

[0065] In a 500 mL three-necked flask, intermediate compound L1 (11.06 g, 20 mmol) was stirred with 200 mL of N,N-dimethylformamide. N-bromosuccinimide (4.28 g, 24 mmol) was added at room temperature, and the mixture was stirred for 8 hours. Methanol was added to the reaction solution, and the resulting yellow solid was filtered. The solid was recrystallized from toluene and dried under vacuum to give product A-1: ​​8.86 g, yield: 70%, MS (m / z) (M+): 631.

[0066] Compounds A-2 and A-3 used in the following synthesis examples can be prepared by similar methods as described above, and will not be repeated here.

[0067] Example 2 of intermediate synthesis

[0068] The preparation method was the same as that for compound L1, except that compound K4 (4.47 g, 25 mmol) was used to replace compound K1, and the final product L4 was 9.31 g, yield: 85%, MS (m / z) (M+): 437.

[0069] The preparation method was the same as that of compound A-1, except that compound L4 (8.76 g, 20 mmol) was used to replace compound L1, and the final product A-4 was obtained: 9.18 g, yield: 89%, MS (m / z) (M+): 515.

[0070] Example 3 of intermediate synthesis

[0071] The preparation method was the same as that of compound L1, except that compounds H5 (7.67 g, 25 mmol) and K5 (7.15 g, 25 mmol) were used to replace compounds H1 and K1, respectively. The final product L5 was 9.38 g, yield: 80%, MS (m / z) (M+): 468.

[0072] The preparation method was the same as that of compound A-1, except that compound L5 (9.38, 20 mmol) was used to replace compound L1, and the final product A-5 was obtained: 9.85 g, yield: 90%, MS (m / z) (M+): 546.

[0073] Example 4 of intermediate synthesis

[0074] The preparation method was the same as that of compound L1, except that compounds H6 (7.67 g, 25 mmol) and K6 (7.15 g, 25 mmol) were used to replace compounds H1 and K1, respectively. The final product L6 was 9.59 g, yield: 82%, MS (m / z) (M+): 468.

[0075] The preparation method was the same as that for compound A-1, except that compound L6 (9.38, 20 mmol) was used to replace compound L1, and the final product A-6 was obtained: 9.73 g, yield: 89%, MS (m / z) (M+): 546.

[0076] Compounds A-7 and A-9 used in the following synthesis examples can be prepared by similar methods as described above, and will not be repeated here.

[0077] Example 5 of intermediate synthesis

[0078] The preparation method was the same as that of compound L1, except that compounds H10 (7.67 g, 25 mmol) and K10 (3.18 g, 25 mmol) were used to replace compounds H1 and K1, respectively. The final product L10 was 6.95 g, yield: 90%, MS (m / z) (M+): 309.

[0079] The preparation method was the same as that of compound A-1, except that compound L10 (6.18 g, 20 mmol) was used to replace compound L1, and the final product A-10 was obtained: 6.98 g, yield: 90%, MS (m / z) (M+): 387.

[0080] Example 6 of intermediate synthesis

[0081] The preparation method was the same as that of compound G1, except that compound F11 (5.08 g, 40 mmol) was used to replace compound F1, and the final product G11 was 11.37 g, yield: 92%, MS (m / z) (M+): 309.

[0082] The preparation method was the same as that of compound A-1, except that compound G11 (10.81 g, 35 mmol) was used to replace compound G1, and the final product A-11 was obtained: 11.54 g, yield: 85%, MS (m / z) (M+): 387.

[0083] Compounds A-12 and A-13 used in the following synthesis examples can be prepared by similar methods as described above, and will not be repeated here.

[0084] Example 7 of intermediate synthesis

[0085] Compound E16 (9.6 g, 40 mmol) and N-bromosuccinimide (7.12 g, 40 mmol) were dissolved in 200 mL of DMF solvent and stirred at 60 °C for 10 h under a nitrogen atmosphere. After cooling the reaction system to room temperature, the DMF was removed and the concentrated reaction solution was removed using a rotary evaporator. The concentrate was then dissolved in 200 mL of dichloromethane, and the organic phase was washed three times with deionized water. After separation, the organic phase was used to remove the solvent using a rotary evaporator to obtain the crude product. The crude product was purified by column chromatography to give intermediate A-16: 10.14 g, yield: 80%. MS (m / z) (M+): 317.

[0086] Compounds A-14 and A-15 used in the following synthesis examples can be prepared by similar methods as described above, and will not be repeated here.

[0087] Synthesis Example 1

[0088] In a 250 mL three-necked flask, under nitrogen protection, 50 mL of toluene, 25 mL of ethanol, and 25 mL of water were added. Then, compound A-1 (6.33 g, 10 mmol), compound B-1 (1.22 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.3 mmol) were added. The mixture was heated to 80 °C and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was dissolved in toluene and filtered to remove the solid insoluble matter. The product C-1 was then recrystallized to give product C-1: 5.36 g, yield: 85%, MS (m / z) (M+): 629.

[0089] Synthesis Example 2

[0090] The preparation method was the same as in Example 1, except that compounds A2 (6.24 g; 10 mmol) and B2 (1.72 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-2 was obtained: 5.37 g, yield: 80%, MS (m / z) (M+): 670.

[0091] 1H NMR (500 MHz, Acetone-d6) δ 9.63 (d,J= 2.0 Hz, 1H), 8.46 – 8.39(m, 2H), 8.29 – 8.18 (m, 8H), 8.07 – 8.00 (m, 2H), 7.96 – 7.91 (m, 1H), 7.86– 7.81 (m, 2H), 7.68 (t,J= 7.4 Hz, 1H), 7.60 – 7.43 (m, 10H), 7.43 – 7.36 (m,1H), 7.25 – 7.20 (m, 2H). Synthesis Example 3

[0092] The preparation method was the same as in Example 1, except that compounds A-1 and B-1 were replaced with compounds A-3 (6.33 g; 10 mmol) and B-3 (2.46 g; 10 mmol), and the final product C-3 was obtained: 6.79 g, yield: 90%, MS (m / z) (M+): 753.

[0093] Synthesis Example 4

[0094] The preparation method was the same as in Example 1, except that compounds A-4 (5.16 g; 10 mmol) and B-4 (2.86 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-4 was obtained: 5.42 g, yield: 80%, MS (m / z) (M+): 677.

[0095] Synthesis Example 5

[0096] The preparation method was the same as in Example 1, except that compounds A-5 (5.47 g; 10 mmol) and B-5 (2.46 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-5 was obtained: 5.75 g, yield: 86%, MS (m / z) (M+): 668.

[0097] 1H NMR (500 MHz, Acetone-d6) δ 9.63 (d,J= 2.0 Hz, 1H), 8.66 (d,J= 8.0Hz, 1H), 8.38 – 8.33 (m, 1H), 8.28 – 8.15 (m, 9H), 8.15 – 8.10 (m, 1H), 8.05– 7.94 (m, 3H), 7.92 – 7.87 (m, 2H), 7.74 (d,J= 8.1 Hz, 1H), 7.59 – 7.46 (m,7H), 7.25 – 7.19 (m, 2H). Synthesis Example 6

[0098] The preparation method was the same as in Example 1, except that compounds A-6 (5.47 g; 10 mmol) and B-6 (2.22 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-6 was obtained: 5.81 g, yield: 90%, MS (m / z) (M+): 644.

[0099] 1 H NMR (500 MHz, Acetone-d6) δ 8.70 – 8.64 (m, 1H), 8.55 – 8.50 (m,1H), 8.41 – 8.34 (m, 2H), 8.29 – 8.11 (m, 7H), 8.05 (d,J= 7.1 Hz, 1H), 8.00 –7.97 (m, 1H), 7.91 – 7.88 (m, 1H), 7.74 (d,J= 8.1 Hz, 1H), 7.68 – 7.48 (m,13H). Synthesis Example 7

[0100] The preparation method was the same as in Example 1, except that compounds A-7 (5.47 g; 10 mmol) and B-7 (1.79 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-7 was obtained: 5.48 g, yield: 91%, MS (m / z) (M+): 601.

[0101] Synthesis Example 8

[0102] The preparation method was the same as in Example 1, except that compounds A-8 (5.47 g; 10 mmol) and B-8 (2.31 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-8 was obtained: 5.95 g, yield: 91%, MS (m / z) (M+): 654.

[0103] Synthesis Example 9

[0104] The preparation method was the same as in Synthesis Example 1, except that compounds A-9 (5.47 g; 10 mmol) and B-9 (1.22 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-9 was obtained: 4.58 g, yield: 84%, MS (m / z) (M+): 544.

[0105] 1 H NMR (500 MHz, Acetone-d6) δ 9.63 (d,J= 2.0 Hz, 1H), 8.31 – 8.16(m, 7H), 8.02 – 7.96 (m, 1H), 7.93 – 7.88 (m, 1H), 7.74 (d,J= 8.1 Hz, 1H),7.59 – 7.45 (m, 10H), 7.42 – 7.36 (m, 1H), 7.25 – 7.19 (m, 2H). Synthesis Example 10

[0106] The preparation method was the same as in Example 1, except that compounds A-10 (3.88 g; 10 mmol) and B-10 (2.86 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-10 was obtained: 4.56 g, yield: 83%, MS (m / z) (M+): 549.

[0107] Synthesis Example 11

[0108] The preparation method was the same as in Example 1, except that compounds A-11 (3.88 g; 10 mmol) and B-11 (2.86 g; 10 mmol) were replaced with compounds A-1 and B-1, and the final product C-11 was obtained: 4.57 g, yield: 83%, MS (m / z) (M+): 549.

[0109] Synthesis Example 12

[0110] The preparation method was the same as in Example 1, except that compounds A-12 (3.88 g; 10 mmol) and B-12 (2.86 g; 10 mmol) were replaced with compounds A-1 and B-1, and the final product C-12 was obtained: 4.46 g, yield: 81%, MS (m / z) (M+): 550.

[0111] Synthesis Example 13

[0112] The preparation method was the same as in Example 1, except that compounds A-13 (3.83 g; 10 mmol) and B-13 (2.86 g; 10 mmol) were replaced with compounds A-1 and B-1, and the final product C-13 was obtained: 4.85 g, yield: 89%, MS (m / z) (M+): 544.

[0113] 1 H NMR (500 MHz, Acetone-d6) δ 8.91 – 8.88 (m, 1H), 8.84 (d,J= 2.0Hz, 1H), 8.30 – 8.19 (m, 4H), 8.15 – 8.07 (m, 4H), 8.07 – 8.02 (m, 1H), 7.90(d,J= 7.6 Hz, 1H), 7.63 – 7.43 (m, 10H), 7.42 – 7.36 (m, 1H), 7.24 – 7.18 (m,1H). Synthesis Example 14

[0114] The preparation method was the same as in Example 1, except that compounds A-14 (3.07 g; 10 mmol) and B-14 (2.86 g; 10 mmol) were used to replace A-1 and B-1, and the final product C-14 was obtained: 4.03 g, yield: 86%, MS (m / z) (M+): 468.

[0115] 1H NMR (500 MHz, Acetone-d6) δ 9.62 (t,J= 1.4 Hz, 1H), 9.23 (d,J= 2.1Hz, 1H), 8.59 – 8.53 (m, 1H), 8.26 – 8.18 (m, 5H), 8.14 – 8.08 (m, 2H), 8.00– 7.95 (m, 1H), 7.86 – 7.81 (m, 1H), 7.68 – 7.58 (m, 5H), 7.58 – 7.47 (m, 3H). Synthesis Example 15

[0116] The preparation method was the same as in Example 1, except that compounds A-15 (3.07 g; 10 mmol) and B-15 (2.86 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C15 was obtained: 4.07 g, yield: 87%, MS (m / z) (M+): 468.

[0117] Synthesis Example 16

[0118] The preparation method was the same as in Example 1, except that compounds A-16 (3.18 g; 10 mmol) and B-16 (2.86 g; 10 mmol) were used to replace compounds A-1 and B-1, and the final product C-16 was obtained: 4.32 g, yield: 90%, MS (m / z) (M+): 479.

[0119] Comparative compounds .

[0120] Material performance evaluation The compounds prepared in the synthesis examples of this invention and the comparative compound were subjected to thermal stability tests, and the test steps are as follows: The test material was placed in a thermal stabilizer and sublimated at 280℃ for 240 hours. The resulting solid sample was then dissolved and diluted with the mobile phase. The change in material purity before and after the experiment was measured using high-performance liquid chromatography (HPLC). A smaller difference in purity indicates better thermal stability of the material.

[0121] To demonstrate the higher stability of the compounds provided by this invention, the molecular structures of the compounds prepared in the synthesis examples and the comparative compounds were geometrically optimized and vibrationally analyzed (Opt+freq) using ORCA software based on density functional theory (DFT) calculations (basis set level set: b3lyp-d3 / 6-31G(d), charge number 0). The ground-state structures and HOMO levels of the compounds were obtained as the basis for subsequent calculations. Based on the optimized ground-state structure and the optimal ground-state conformation of the luminescent molecule, the excited-state energy level T1 was calculated using the higher-order equation of motion coupled cluster method B3LYP, along with multiple excitation configurations and the def2-TZVP basis set. Generally, the shallower the HOMO (the smaller the absolute value of HOMO, i.e., |HOMO|), the smaller the hole injection barrier, which is more conducive to hole injection. As the first host material of the first luminescent layer in a dual-emissive layer, its T1 energy level should be greater than that of the second host material of the second luminescent layer (approximately 1.73 eV); otherwise, the dual-emissive-layer mechanism cannot be utilized. The results are shown in Table 1.

[0122] Table 1

[0123] As can be seen from the table above, compared with the comparative compound, the compound provided by the present invention not only has a suitable triplet energy but also a small difference in purity before and after sublimation, indicating that it has high stability. The |HOMO| value is small, indicating that the compound provided by the present invention has significant advantages in stability and energy level matching.

[0124] Furthermore, compared with the comparative compound DB01, the purity difference of compound C-16 provided by the present invention before and after sublimation is significantly smaller and its stability is higher, while the comparative compound DB01 is prone to deterioration in high-temperature processes.

[0125] Compared with the comparative compound DB02, the purity difference of compound C-15 provided by the present invention before and after sublimation is significantly smaller, indicating that the stability of the compound provided by the present invention is significantly improved.

[0126] Furthermore, this invention connects the tri-benzo[1,12-bcd]furan group at position 7 or 12 of the benzenexane core in a direct manner. Due to the steric hindrance created by the two segment planes, which hinders the free rotation of the two segments connected by the single bond, the molecule as a whole can maintain good rigidity, which is beneficial to improving the stability of the material. In contrast, the tri-benzo[1,12-bcd]furan group of the comparative compound DB03 is connected to the benzenexane through a large spacer group, which not only increases the flexibility of the molecule but also increases the molecular weight. During long-term thermal processes such as sublimation and vapor deposition, the flexible sites are prone to decomposition and deterioration, reducing the stability of the material. Moreover, the large spacer group is not conducive to the dense packing of molecules and the transport of charge carriers.

[0127] The HOMO of the comparative compound DB04 is too deep, which is not conducive to hole injection.

[0128] The comparative compound DB05 uses anthracene as its core structure, resulting in a T1 level of only 1.73 eV, which prevents the realization of the double-emissivity mechanism and thus hinders the effective improvement of efficiency.

[0129] In summary, the compounds provided by this invention exhibit high stability and low |HOMO| values, which are beneficial for hole injection, by monosubstituting the tribenzo[1,12-bcd]furan group at least at position 7 of benzenexane, further by disubstituting the tribenzo[1,12-bcd]furan group at positions 4 and 7 or 7 and 12 of benzenexane, and even further by trisubstituting the tribenzo[1,12-bcd]furan group at positions 4, 7, and 12 of benzenexane, and by directly connecting the tribenzo[1,12-bcd]furan group at position 7 or 12 of the benzenexane core.

[0130] The compounds provided by this invention are benzo[anthracene] As the parent nucleus (the numbers in the structural formula represent the connection sites between the benzene anthracene parent nucleus and other fragments, and the connection sites described in this invention are consistent with this structural formula).

[0131] OLED manufacturing and characterization Device Examples The organic electroluminescent device provided by the present invention includes an anode, a hole transport region, a first light-emitting layer, a second light-emitting layer, an electron transport region, and a cathode sequentially disposed on a substrate. Furthermore, the hole transport region includes a hole injection layer, a hole transport layer, and a light-emitting auxiliary layer; the electron transport region includes an electron transport layer and an electron injection layer.

[0132] Furthermore, the first light-emitting layer is composed of a first host material and a first guest material, and the host material of the first light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0133] Furthermore, the second light-emitting layer is composed of a second host material and a second guest material. The host material of the second light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0134] The compound described in this invention can be used in the first light-emitting layer of the aforementioned organic electroluminescent device.

[0135] In this embodiment, the anode uses a commonly used anode material in the art, such as ITO, Ag, or their multilayer structures. The hole injection layer uses a commonly used hole injection material in the art, with F4TCNQ, HATCN, NDP-9, etc., added for doping. The hole transport layer uses a commonly used hole transport material in the art. The light-emitting layer uses the host and guest material composition provided by this invention. The electron transport layer uses a commonly used electron transport material in the art. The electron injection layer uses a commonly used electron injection material in the art, such as LiQ, LiF, Yb, etc. The cathode uses a commonly used material in the art, such as metallic Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0136] The electrode fabrication method and the deposition method of each functional layer in this embodiment are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, and will not be described in detail here. Only some process details and testing methods in the fabrication process are supplemented as follows: Device Example 1 The substrates used in this invention are all subjected to the following operations: the ITO / Ag / ITO substrate is patterned to give it a light-emitting area of ​​3mm × 3mm, then ultrasonicated with water / isopropanol, irradiated with UV / ozone, and then dried at 100°C. Afterwards, the ITO / Ag / ITO substrate is mounted on the substrate support of a vacuum deposition apparatus, and the pressure is adjusted to make the vacuum rate 1 × 10⁻⁶. -7The following operations were then performed: First, a hole injection layer was formed on the ITO layer (anode) formed on the substrate by vacuum deposition of compounds HT01 and PD01 (mass ratio of HT01 to PD01 of 97:3) with a thickness of 10 nm. Next, a hole transport layer was formed on the hole injection layer by vacuum deposition of compound HT01 with a thickness of 100 nm. Then, an electron blocking layer was formed on the hole transport layer by vacuum deposition of compound BP01 with a thickness of 5 nm. A first host material C-1 and a dopant material BD01 were co-deposited on the electron blocking layer, such that the mass ratio of compound C-1 to compound BD01 was 97:3, forming a first light-emitting layer with a thickness of 5 nm. A second host material BH2-01 and a dopant material BD01 were co-deposited on the first light-emitting layer, such that the mass ratio of compound BH2-01 to compound BD01 was 98:2, forming a second light-emitting layer with a thickness of 15 nm. Compound HB01 was vapor-deposited on the second emitting layer to form a hole-blocking layer with a thickness of 5 nm. Then, on the hole-blocking layer, compound ET01 and compound LiQ (mass ratio of ET01 to LiQ 1:1) were vacuum-deposited to a thickness of 30 nm to form an electron transport layer. Next, Yb was vacuum-deposited to a thickness of 1 nm on the electron transport layer to form an electron injection layer. Then, Mg and Ag (mass ratio of Mg to Ag 1:9) were deposited to a thickness of 15 nm on the electron injection layer to form a cathode. Finally, compound CP01 was deposited to a thickness of 50 nm on the cathode to form a capping layer. The vapor-deposited substrate was then encapsulated. A UV adhesive was applied to the cleaned cover plate using a coating equipment. The coated cover plate was then moved to the lamination section, and the vapor-deposited substrate was placed on top of the cover plate. Finally, the substrate and cover plate were laminated using a bonding equipment, and the UV adhesive was simultaneously photocured to fabricate a top-emitting organic light-emitting device. The device structure is described in [reference needed]. Figure 1 .

[0137] Except for the first host material C-1, the molecular structural formulas of the remaining layers are as follows:

[0138]

[0139] .

[0140] Device Examples 2-16 Using the above method, organic electroluminescent devices were made from the compounds in the other device embodiments in Table 2. Specifically, blue organic electroluminescent devices Examples 2-16 were made by replacing compound C-1 in device embodiment 1 with the first host material shown in Table 2.

[0141] Device Comparison Examples 1-5 Organic electroluminescent devices were fabricated using the compounds in the device comparison examples in Table 2 using the above method. Specifically, blue organic electroluminescent devices (Comparative Examples 1-5) were fabricated by replacing compound C-1 in device Example 1 with the first host material shown in Table 2.

[0142] The OLED devices described above were tested using standard methods. For this purpose, J = 10 mA / cm² was used. 2 The driving voltage and luminous efficiency of the organic electroluminescent device were determined at a current density of J = 20 mA / cm². LT97 indicates that the fabricated blue light-emitting device is capable of operating at this current density. 2 When operating, the luminous intensity drops to 97% of its initial value L0 after time LT97.

[0143] The testing instruments and methods used to perform performance testing on the OLED devices of the above embodiments and comparative examples are as follows: Luminous efficacy (CE) (cd / A) and chromaticity coordinates (CIEy) were measured using a PhotoResearch PR-655 spectral scanner. Current density and turn-on voltage: tested using a Keithley 2400 digital source meter; The luminous efficiency of blue light devices is greatly affected by chromaticity. The industry generally uses the BI value as the basis for the efficiency of blue light devices. BI (Blue index) is obtained by dividing the luminous efficiency CE (cd / A) by the chromaticity coordinate (CIEy). Lifetime testing: Using a silicon photonics-based OLED device lifetime testing system.

[0144] The performance test results of the above devices are listed in Table 2.

[0145] Table 2

[0146] The device evaluation results above show that the device performance, especially the voltage performance, prepared with the material of this invention is significantly improved. This is because the HOMO level of the first host material selected in this invention is shallow, reducing the barrier to hole injection. Furthermore, it can be seen that the materials used in Comparative Examples 1 and 2 have poor thermal stability, resulting in significantly worse lifetime performance. The DB05 material in Comparative Example 5 has a smaller T1, thus its efficiency is not as good as that of the device of this invention. In summary, this invention, through comprehensive control of limiting the substitution sites of benzo[a]phenanthrene-furan and the number of non-hydrogen substituents on benz[a]anthracene, obtains a first host material with good stability, a shallow HOMO level, and a high T1 level. Applying this material to a dual-emitting-layer device yields significantly superior results.

[0147] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. An organic compound for use in a dual-emitting-layer blue light device, characterized in that, The general structural formula of the organic compound is shown below: I； Ar1, Ar2, and Ar3 may be the same or different, and each is independently selected from one of hydrogen, deuterated or non-deuterated phenyl, deuterated or non-deuterated naphthyl, deuterated or non-deuterated phenanthryl, deuterated or non-deuterated trefyl, deuterated or non-deuterated pyrene, deuterated or non-deuterated benzophenanthryl, deuterated or non-deuterated tribenzo[1,12-bcd]furanyl, and at least one is selected from tribenzo[1,12-bcd]furanyl; In Formula I, any hydrogen atom can be replaced by deuterium.

2. The organic compound according to claim 1, characterized in that, The tri-benzo[1,12-bcd]furanyl group is selected from one of the following structures: 、 、 、 、 。 3. The organic compound according to claim 1, characterized in that, Ar1, Ar2, and Ar3 are all not hydrogen.

4. The organic compound according to claim 1, characterized in that, Only one of Ar2 and Ar3 is hydrogen.

5. The organic compound according to claim 1, characterized in that, Both Ar2 and Ar3 are hydrogen.

6. The organic compound according to claim 1, characterized in that, Ar1 is tri-benzo[1,12-bcd]furanyl.

7. The organic compound according to claim 1, characterized in that, The Ar3 is selected from one of hydrogen, deuterated or non-deuterated phenyl, or deuterated or non-deuterated tribenzo[1,12-bcd]furanyl.

8. The organic compound according to claim 1, characterized in that, The organic compound is selected from the following structures: 。 9. A double-emitting-layer blue organic electroluminescent device, characterized in that, It includes an anode, a hole transport region, a first light-emitting layer, a second light-emitting layer, an electron transport region, and a cathode, which are sequentially disposed on a substrate; wherein the first light-emitting layer comprises an organic compound as described in any one of claims 1 to 8.

10. The dual-emitting-layer blue organic electroluminescent device according to claim 9, characterized in that, The first light-emitting layer comprises a first host material and a first guest material, wherein the first host material is selected from the organic compounds described in any one of claims 1 to 8.

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