Organic compounds and their applications and organic electroluminescent devices

Abstract

The present invention relates to an organic compound and its application and an organic electroluminescent device. The organic compound is as shown in Formula I, wherein L1 and L2 are the same or different, each independently does not exist or is selected from a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group; Ar1 ​​and Ar2 are the same or different, each independently selected from a substituted or unsubstituted aryl group and a substituted or unsubstituted heteroaryl group. When the organic compound of the present invention is applied to an organic electroluminescent device, the device has higher luminous efficiency and longer service life.

Description

Technical Field

[0001] The invention relates to the field of organic electroluminescent devices, and in particular to an organic compound and application thereof and an organic electroluminescent device. Background Art

[0002] In 1987, Tang et al. from Kodak Company prepared a double-layer organic light-emitting diode (OLED) by vacuum evaporation, using aromatic diamine as hole transport material and 8-hydroxyquinoline aluminum as light-emitting and electron transport material. At a driving voltage of less than 10V, the device luminous brightness reached 1000cd / m 2 , the luminous efficiency is 1.5lm / W.

[0003] With the continuous advancement of OLED technology in the two major fields of lighting and display, the device structure and the materials of each functional layer need to be further optimized and developed. Red, green and blue have high luminous efficiency, long service life and high color purity, which are very important for display applications. There are many reports on high-performance red and green OLEDs. Compared with red and green OLEDs, the performance of blue OLEDs is relatively poor, so it is necessary to improve its performance. Compared with blue phosphorescent OLEDs, blue fluorescent OLEDs tend to have longer life and higher color purity. However, the internal quantum efficiency of traditional fluorescent OLEDs is limited to 25% because singlet and triplet excitons are generated in a ratio of about 1:3 under electrical excitation. Therefore, the key to improving the efficiency of fluorescent OLEDs is to use triplet excitons. The triplet-triplet annihilation mechanism (TTA) converts the triplet excited state (T1) into the singlet excited state (S1), so that the internal quantum efficiency can reach 40% to 62.5%. There have been some reports on efficient blue fluorescence using TTA, in which anthracene derivatives are used as the main material, but nowadays organic electroluminescent devices have low luminescence efficiency and short service life, so improving the efficiency and life of blue light devices is an urgent breakthrough point. Summary of the invention

[0004] In order to overcome the problems of high driving voltage, low luminous efficiency and short service life of organic electroluminescent devices provided by the prior art, the efficiency of blue light devices is improved by improving the utilization rate of invalid triplet excitons in the electrogenerated excitons in OLED blue light devices, while at the same time increasing the service life of the devices.

[0005] In a first aspect, the present invention provides an organic compound as shown in formula I,

[0006]

[0007] In Formula I, L 1 and L2 are the same or different, each independently absent or selected from substituted or unsubstituted arylene and substituted or unsubstituted heteroarylene; Ar 1 and Ar 2 are the same or different and are each independently selected from substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl.

[0008] According to the organic compound of the present invention, preferably, in Formula I, L 1 and L 2 are the same or different, each independently absent or selected from substituted or unsubstituted C 6 -C 20 An arylene group and a substituted or unsubstituted C 3 -C 20 The heteroarylene group.

[0009] According to the organic compound of the present invention, preferably, in formula I, Ar 1 and Ar 2 Each independently selected from substituted or unsubstituted C 6 -C 30 The aryl group and substituted or unsubstituted C 3 -C 30 The heteroaryl group.

[0010] According to the organic compound of the present invention, preferably, in Formula I, the heteroatom in the heteroaryl group is selected from one or more of nitrogen, oxygen, sulfur, phosphorus and silicon; the heteroatom in the heteroarylene group is selected from one or more of nitrogen, oxygen, sulfur, phosphorus and silicon.

[0011] According to the organic compound of the present invention, preferably, in Formula I, the substituents in the substituted arylene group, substituted heteroarylene group, substituted aryl group and substituted heteroaryl group are each independently selected from C 1 -C 10 Alkyl, C 1 -C 10 One or more of alkoxy, cyano and halogen.

[0012] According to the organic compound of the present invention, preferably, in Formula I, L 1 is absent, or is phenylene, naphthylene, anthracene or phenanthrene.

[0013] According to the organic compound of the present invention, preferably, in Formula I, L 2 is absent, or is phenylene, naphthylene, anthracene or phenanthrene.

[0014] According to the organic compound of the present invention, preferably, in formula I, Ar 1 and Ar 2each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted 9,9-dimethylfluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted 9-phenylcarbazolyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted phenanthroline, substituted or unsubstituted 9,9'-spirobifluorenyl, substituted or unsubstituted substituted or unsubstituted benzo[9,10]phenanthrenyl, substituted or unsubstituted 9,9-dimethylfluorenyl, substituted or unsubstituted 9,9-diphenylfluorenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted isobenzofuranyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted substituted or unsubstituted isobenzothiophenyl, substituted or unsubstituted indolizinyl, substituted or unsubstituted bicarbazolyl, substituted or unsubstituted azabenzo[9,10]phenanthryl, substituted or unsubstituted diazabenzo[9,10]phenanthryl, substituted or unsubstituted xanthenyl, substituted or unsubstituted azacarbazolyl, substituted or unsubstituted azadibenzofuranyl, substituted or unsubstituted azadibenzothiophenyl, substituted or unsubstituted diphenylphosphinoyl, substituted or unsubstituted triphenylsilanyl and substituted or unsubstituted fluoranthenyl.

[0015] Specific examples of organic compounds according to the present invention include, but are not limited to:

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] In a second aspect, the present invention provides an application of an organic compound as shown in the above formula I in an organic electroluminescent device. According to an embodiment of the present invention, in the organic electroluminescent device, the organic compound is used as a light-emitting layer material, preferably as a light-emitting layer host material, and more preferably as a blue light host material.

[0025] In a third aspect, the present invention provides an organic electroluminescent device, which comprises a light-emitting layer, wherein the light-emitting layer comprises the organic compound represented by formula I described above.

[0026] According to some embodiments of the present invention, the light-emitting layer also includes a guest material, which is preferably a compound that produces emission via at least one of phosphorescence, fluorescence, TADF (thermally activated delayed fluorescence), MLCT (metal to ligand charge transfer), HLCT (with hybrid CT state) and triplet-triplet annihilation methods.

[0027] According to some embodiments of the present invention, the organic electroluminescent device of the present invention further comprises an anode, a hole injection layer, a hole transport layer, an optional electron blocking layer, an optional hole blocking layer, an electron transport layer, an electron injection layer and a cathode.

[0028] According to some embodiments of the present invention, the anode material forming the anode is generally preferably a material with a large work function. For example, the anode material used in the present invention is selected from one or more of the following materials: metals, such as vanadium, chromium, copper and gold, or other alloys: metal oxides, such as zinc oxide, indium oxide, indium tin oxide, indium zinc oxide and tin dioxide, combinations of metals and oxides, such as zinc oxide: aluminum, but not limited thereto.

[0029] According to some embodiments of the present invention, the material forming the hole injection layer has the ability to transport holes, so the material of the hole injection layer has the effect of injecting holes into the anode, has an excellent hole injection effect on the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from moving to the electron injection layer or the electron injection material, and has excellent thin film forming ability. The HOMO of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0030] According to some embodiments of the present invention, the hole injection material and the hole transport material include at least one of aromatic amine derivatives (such as NPB, SqMA1), hexaazatriphenylene derivatives (such as HACTN), indolecarbazole derivatives, conductive polymers (such as PEDOT / PSS), phthalocyanine or porphyrin derivatives, dibenzoindenofluorene amine, and spirobifluorene amine, but are not limited thereto.

[0031] According to some embodiments of the present invention, the hole injection layer and the hole transport layer may be formed by, for example, an aromatic amine derivative of the following general formula:

[0032]

[0033] The groups R1 to R9 in the above general formula are each independently selected from a single bond, hydrogen, deuterium, alkyl, benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, triphenylene, pyrene, fluorene, dimethylfluorene, spirobifluorene, carbazole, thiophene, benzothiophene, dibenzothiophene, furan, benzofuran, dibenzofuran, indole, indolecarbazole, indenocarbazole, pyridine, pyrimidine, imidazole, thiazole, quinoline, isoquinoline, quinoxaline, quinazoline, porphyrin, carboline, pyrazine, pyridazine or triazine.

[0034] According to some embodiments of the present invention, the material for forming the electron blocking layer is not particularly limited. Generally, compounds that meet the first and / or second conditions below can be considered for use:

[0035] First: It has a shallower LUMO energy level (smaller absolute value), the purpose of which is to reduce the number of electrons leaving the light-emitting layer, thereby increasing the probability of electrons and holes recombining in the light-emitting layer.

[0036] Second: It has a larger triplet energy, the purpose of which is to reduce the number of excitons leaving the light-emitting layer, thereby increasing the efficiency of exciton conversion to luminescence.

[0037] According to some embodiments of the present invention, the materials forming the electron blocking layer include but are not limited to aromatic amine derivatives (such as NPB) and spirobifluorenamine (such as SpMA2), wherein some electron blocking materials have structures similar to those of hole injection materials and hole transport materials.

[0038] According to some embodiments of the present invention, the material of the hole blocking layer may also preferably be a compound having the following first and / or second conditions:

[0039] First: It has a deeper HOMO energy level (larger absolute value), the purpose of which is to reduce the number of holes leaving the light-emitting layer, thereby increasing the probability of electrons and holes recombining in the light-emitting layer.

[0040] Second: It has a larger triplet energy, the purpose of which is to reduce the number of excitons leaving the light-emitting layer, thereby increasing the efficiency of exciton conversion to luminescence.

[0041] According to some embodiments of the present invention, the material forming the hole blocking layer may include, for example, phenanthroline derivatives (eg, Bphen, BCP), triphenylene derivatives, benzimidazole derivatives, but is not limited thereto.

[0042] According to some embodiments of the present invention, the electron injection layer is a layer for injecting electrons from the electrode, and the electron injection material is preferably a compound having the following properties: it has the ability to transport electrons, has the effect of injecting electrons from the cathode, has an excellent effect of injecting electrons into the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from moving to the hole injection layer, and also has excellent thin film forming ability. Materials for the electron injection layer include, for example, LiF, CsF, Cs 2 CO 3 , LiQ, but not limited to.

[0043] According to some embodiments of the present invention, the cathode material is preferably formed of a material with a small work function, which can smoothly inject electrons into the organic material layer. The cathode material that can be used in the present disclosure can be selected from one or more of the following materials, one or more of Al, Mg and Ag.

[0044] The present invention has at least the following specific advantages:

[0045] First, the mother core of the present invention is anthracene connected to para-deuterated benzene connected to anthracene. Anthracene has a TTA effect. The present invention increases the utilization rate of triplet excitons through the synergistic effect of two anthracenes, thereby improving the luminous efficiency of the organic electroluminescent device.

[0046] Second, the deuterium atom in the para-deuterated benzene in the parent core structure has a larger atomic radius than the hydrogen atom, thus having stronger stability; at the same time, the deuterium atom interacts with anthracene to produce a larger angle, which effectively prevents the overlap of anthracene units between molecules, increases the glass transition temperature of the compound, and reduces the crystallinity of the compound, which can effectively improve the luminous efficiency and service life in electroluminescent devices.

[0047] Third, the mother core structure of the present invention has a large band gap and is suitable for being a blue light host. The substituent groups on both sides can fine-tune the HOMO and LUMO of the compound, which can reduce the injection barrier of electrons and holes, thereby reducing the driving voltage of the device. At the same time, the compound of the present invention has a good carrier migration rate and can balance the migration rate of electrons and holes in the device. When applied to organic electroluminescent devices, a wider carrier recombination area can be obtained, thereby improving the luminous efficiency. DETAILED DESCRIPTION

[0048] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0049] The present invention has no particular restrictions on the specific method for preparing the aforementioned compounds. Those skilled in the art can obtain the aforementioned compounds of the present invention according to the specific structural formula provided by the present invention in combination with the conventional process route in the field of organic synthesis, and the present invention hereinafter exemplarily lists several examples to illustrate the preparation method of the compounds of the present invention. Those skilled in the art can also obtain the specific preparation method of all the remaining compounds by replacing the type of raw materials according to the preparation method of the compounds in the following text of the present invention. The present invention no longer describes the preparation methods of all compounds in detail, and those skilled in the art should not be construed as limiting the present invention.

[0050] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all the raw materials used are common commercial products. Unless otherwise specified, the room temperature described below means 25±1°C.

[0051] Preparation Example 1:

[0052]

[0053] Synthesis of intermediate M-1: In a 500ml three-necked flask, add 1,4-dibromo-deuterated naphthalene (0.05mol), 9-boric acid anthracene (0.1mol), toluene (90ml), ethanol (60ml), and a mixed solution of water (30ml) in sequence, and start stirring. Then add potassium carbonate (0.25mol) and tetrakis(triphenylphosphine)palladium (1mmol) in sequence, raise the temperature to reflux for 7h, and HPLC detects that the raw materials have basically reacted. Add deionized water (200ml) to the reaction solution, stir for 10min, take the organic phase and wash it three times with toluene, combine the organic phases, and dry it over anhydrous magnesium sulfate. Filter the desiccant, spin dry the organic solvent, and separate the residue through a silica gel column to obtain a white solid M-1 (yield: 75%).

[0054] Synthesis of intermediate M: In a 500 ml three-necked flask, M-1 (0.03 mol) was dissolved in N,N-dimethylformamide (150 ml), and N,N-dimethylformamide solution (110 ml) containing NBS (0.06 mol) was added dropwise. After the addition was completed, the temperature was raised to 100 ° C and stirred for 12 h. HPLC detection showed that the reaction of the raw materials was basically completed. The reaction solution was cooled to room temperature and water (300 ml) was added dropwise. After stirring for 30 min, the crude product was filtered and dried to obtain intermediate M (yield 70%).

[0055] Mass spectrum: C38H16D6Br2, theoretical value: 642.05, measured value: 642.1. 1H-NMR (400 MHz, CDCl3) (ppm) δ = 7.49 ~ 7.54 (8H, m), 8.16 ~ 8.20 (4H, m), 8.28 ~ 8.34 (4H, m).

[0056] Preparation Example 2:

[0057]

[0058] Synthesis of compound 1: The synthesis method is the same as that of intermediate M-1, and a white solid is obtained (yield: 72%).

[0059] Mass spectrum: C50H26D6, theoretical value: 638.29, measured value: 638.3. 1H-NMR (400 MHz, CDCl3) (ppm) δ = 7.39 ~ 7.45 (10H, m), 7.53 ~ 7.57 (4H, m), 7.63 ~ 7.67 (4H, m), 8.19 ~ 8.23 ​​(8H, m).

[0060] Preparation Example 3:

[0061]

[0062] Synthesis of compound 5: The synthesis method is the same as that of intermediate M-1, and a white solid is obtained (yield: 72%).

[0063] Mass spectrum: C58H30D6, theoretical value: 738.32, measured value: 738.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.32~7.36 (2H, m), 7.38~7.46 (10H, m), 7.75~7.80 (4H, m), 7.87~7.91 (2H, m), 8.19~8.24 (8H, m), 8.48~8.52 (2H, m), 8.93~8.97 (2H, m).

[0064] Preparation Example 4:

[0065]

[0066] Synthesis of compound 6: The synthesis method is the same as that of intermediate M-1, and a white solid is obtained (yield: 74%).

[0067] Mass spectrum: C58H30D6, theoretical value: 738.32, measured value: 738.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.36~7.40 (2H, m), 7.40~7.45 (8H, m), 7.54~7.65 (6H, m), 7.97~8.01 (2H, m), 8.04~8.11 (4H, m), 8.19~8.23 (8H, m).

[0068] Preparation Example 5:

[0069]

[0070] Synthesis of compound 11: The synthesis method is the same as that of intermediate M-1 to obtain a white solid (yield: 71%).

[0071] Mass spectrum: C70H38D6, theoretical value: 890.38, measured value: 890.4. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.25~7.29 (4H, m), 7.31~7.34 (4H, m), 7.38~7.49 (14H, m), 7.76~7.81 (4H, m), 8.19~8.24 (8H, m), 8.98~9.02 (4H, m).

[0072] Preparation Example 6:

[0073]

[0074] Synthesis of compound 18: The synthesis method is the same as that of intermediate M-1, and a white solid is obtained (yield: 69%).

[0075] Mass spectrum: C62H30D6O2, theoretical value: 818.31, measured value: 818.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.28~7.33 (2H, m), 7.37~7.45 (10H, m), 7.52~7.56 (2H, m), 7.60~7.65 (2H, m), 7.67~7.71 (2H, m), 7.95~8.00 (2H, m), 8.19~8.23 (8H, m), 9.43~9.46 (2H, m).

[0076] Preparation Example 7:

[0077]

[0078] Synthesis of compound 24: The synthesis method is the same as that of intermediate M-1 to obtain a white solid (yield: 73%).

[0079] Mass spectrum: C62H30D6S2, theoretical value: 850.26, measured value: 850.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.29~7.33 (2H, m), 7.41~7.45 (10H, m), 7.54~7.59 (2H, m), 7.84~7.88 (2H, m), 7.97~8.01 (2H, m), 8.10~8.14 (2H, m), 8.19~8.24 (8H, m), 8.43~8.47 (2H, m).

[0080] Preparation Example 8:

[0081]

[0082] Synthesis of compound 47: The synthesis method is the same as that of intermediate M-1 to obtain a white solid (yield: 72%).

[0083] Mass spectrum: C70H34D6O2, theoretical value: 918.34, measured value: 918.4. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.28~7.31 (2H, m), 7.41~7.45 (8H, m), 7.49~7.55 (4H, m), 7.59~7.64 (4H, m), 7.67~7.71 (4H, m), 7.97~8.01 (2H, m), 8.19~8.23 (8H, m), 8.52~8.56 (2H, m).

[0084] Preparation Example 9:

[0085]

[0086] Synthesis of compound 64: The synthesis method is the same as that of intermediate M-1 to obtain a white solid (yield: 70%).

[0087] Mass spectrum: C66H34D6, theoretical value: 838.35, measured value: 838.4. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.40~7.46 (8H, m), 7.61~7.72 (10H, m), 7.88~7.92 (2H, m), 8.19~8.23 (8H, m), 8.26~8.29 (2H, m), 8.83~8.86 (2H, m), 9.06~9.10 (2H, m).

[0088] Preparation Example 10:

[0089]

[0090] Synthesis of intermediate 75-1: In a 500 ml three-necked flask, M-1 (0.05mol) was dissolved in N,N-dimethylformamide (240ml), and N,N-dimethylformamide solution (90ml) containing NBS (0.05mol) was added dropwise. After the addition was completed, the temperature was raised to 100°C and stirred for 10h. HPLC detected that the reaction of the raw materials was basically completed. The reaction solution was cooled to room temperature and water (350ml) was added dropwise. After stirring for 30min, the crude product was filtered to obtain the crude product, which was recrystallized three times with dichloromethane and dried to obtain intermediate 75-1 (yield: 53%).

[0091] Synthesis of intermediate 75-1: In a 500ml three-necked flask, add intermediate 75-1 (0.06mol), 2-naphthaleneboric acid (0.06mol), toluene (150ml), ethanol (100ml), and a mixed solution of water (50ml) in sequence, and start stirring. Then add potassium carbonate (0.15mol) and tetrakis(triphenylphosphine)palladium (0.6mmol) in sequence, raise the temperature to reflux for 6h, and HPLC detection shows that the raw materials have basically reacted. Add deionized water (300ml) to the reaction solution, stir for 10min, take the organic phase and wash it three times with toluene, combine the organic phases, and dry it over anhydrous magnesium sulfate. Filter the desiccant, spin dry the organic solvent, and separate the residue through a silica gel column to obtain a white solid 75-1 (yield: 78%).

[0092] Synthesis of intermediate 75-1: The synthesis method is the same as that of intermediate 75-1 to obtain a white solid (yield: 55%).

[0093] Synthesis of compound 75: The synthesis method is the same as that of intermediate 75-2 to obtain a white solid (yield: 75%).

[0094] Mass spectrum: C58H30D6, theoretical value: 738.32, measured value: 738.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.32~7.45 (11H, m), 7.54~7.65 (3H, m), 7.75~7.80 (2H, m), 7.87~7.91 (1H, m), 7.97~8.01 (1H, m), 8.04~8.11 (2H, m), 8.19~8.23 (8H, m), 8.48~8.52 (1H, m), 8.94~8.97 (1H, m).

[0095] Preparation Example 11:

[0096]

[0097] Synthesis of compound 85: The synthesis method is the same as that of intermediate 75-2 to obtain a white solid (yield: 72%).

[0098] Mass spectrum: C64H34D6, theoretical value: 814.35, measured value: 814.3. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.23~7.27 (4H, s), 7.30~7.47 (11H, m), 7.54~7.67 (3H, m), 7.73~7.80 (2H, m), 7.87~7.91 (1H, m), 7.97~8.01 (1H, m), 8.04~8.11 (2H, m), 8.17~8.25 (8H, m), 8.47~8.54 (1H, m), 8.93~8.98 (1H, m).

[0099] Device Example 1

[0100] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol (volume ratio 1:1), baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0101] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 Pa, vacuum evaporating HAT-CN as a hole injection layer on the above anode layer film, the evaporation rate is 0.1nm / s, and the total evaporation film thickness is 1nm; then evaporating the hole transport layer NPB, the evaporation rate is 0.1nm / s, and the thickness is 60nm;

[0102] The electron blocking layer TCTA of the device is vacuum evaporated on the hole transport layer, with an evaporation rate of 0.1nm / s and a total evaporation film thickness of 10nm;

[0103] The light-emitting layer of the device is vacuum-deposited on the electron blocking layer. The light-emitting layer includes a main material and a guest material. The evaporation rate of the main material compound 1 is adjusted to 0.1 nm / s by using a multi-source co-evaporation method. The evaporation rate of the guest material BD is set at 5%, and the total evaporation film thickness is 30 nm.

[0104] The hole blocking layer TPBi of the device was vacuum-deposited on the light-emitting layer at a rate of 0.1 nm / s and a thickness of 5 nm. Then, the electron transport layer was evaporated. The evaporation rates of ET-1 and ET-2 were adjusted to 0.1 nm / s by using a multi-source co-evaporation method, and the total evaporation film thickness was 30 nm.

[0105] LiF with a thickness of 0.5 nm was vacuum-evaporated on the electron transport layer (ETL) as an electron injection layer, and an Al layer with a thickness of 150 nm was used as the cathode of the device.

[0106] The molecular structures involved are as follows:

[0107]

[0108] Device Examples 2-10

[0109] Organic light-emitting devices of device examples 2 to 10 were prepared by a method similar to that of device example 1, except that compound 1 in device example 1 was replaced with a compound shown in Table 1.

[0110] Device Comparison Examples 1-4

[0111] An organic electroluminescent device of Device Comparative Example 1 was prepared by a method similar to that of Device Example 1, except that Compound 7 in Device Example 1 was replaced by ref-1, ref-2, ref-3 and ref-4, respectively.

[0112]

[0113] Test Example 1

[0114] At brightness 1000cd / m 2 The driving voltage and current efficiency of the organic electroluminescent devices prepared in device examples 1 to 10 and device comparative examples 1 to 4 were measured. The results are shown in Table 1.

[0115] Table 1

[0116]

[0117] The above results show that, compared with the comparative example, the organic compound of the present invention has higher device luminescence efficiency when applied to an organic electroluminescent device.

[0118] Test Example 2

[0119] At brightness 1000cd / m 2 The lifespans of the organic electroluminescent devices prepared in device examples 11 to 13 and device comparative examples 5 to 7 were measured. The results are shown in Table 2.

[0120]

[0121]

[0122] The above results show that, compared with the comparative example, the organic electroluminescent compound of the present invention has a longer service life when applied to an organic electroluminescent device.

[0123] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An organic compound as shown in formula I, In Formula I, L1 does not exist, or is phenylene, naphthylene, anthrylene or phenanthrylene; L2 does not exist, or is phenylene, naphthylene, anthrylene or phenanthrylene; Ar1 and Ar2 are the same or different, and are independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted phenanthrenyl; The substituents used in the substitution are each independently selected from C1-C 10 Alkyl, C1-C 10 One or more of alkoxy, cyano and halogen.

2. An organic compound, characterized in that The organic compound is selected from the following compounds:

3. Use of the organic compound according to claim 1 or 2 in an organic electroluminescent device.

4. The use according to claim 3, characterized in that: The organic compound is used as a light-emitting layer material.

5. The use according to claim 4, characterized in that: The organic compound is used as a host material of the light-emitting layer.

6. The use according to claim 4, characterized in that: The organic compound is used as a blue light host material. 7 . An organic electroluminescent device comprising a light-emitting layer, wherein the light-emitting layer comprises the organic compound according to claim 1 or 2 .

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