An organic electroluminescent device

Abstract

The present invention relates to the field of organic electroluminescence, and in particular to an organic electroluminescent device using a novel functional material solution. The organic electroluminescent device of the present invention comprises an anode, a cathode, and one or more organic layers located between the anode and the cathode, wherein the organic layers comprise a light-emitting layer and an electron-assisting layer, wherein the electron-assisting layer is located between the light-emitting layer and the cathode, and wherein the electron-assisting layer comprises a compound represented by the following formula (1): The organic electroluminescent device of the present invention has a low starting voltage, high luminous efficiency, and a longer service life, and can meet the current requirements of panel manufacturers for high-performance materials.

Description

Technical Field

[0001] The present invention relates to the field of organic electroluminescence, and in particular to an organic electroluminescent device using a novel functional material solution. Background Art

[0002] Organic electroluminescent (OLED) devices are a type of device with a sandwich-like structure, including positive and negative electrode film layers and an organic functional material layer sandwiched between the electrode film layers. When voltage is applied to the electrodes of the OLED device, positive charges are injected from the positive electrode and negative charges are injected from the negative electrode. Under the action of the electric field, the positive and negative charges migrate in the organic layer and meet to combine and emit light. Due to the advantages of high brightness, fast response, wide viewing angle, simple process, and flexibility, OLED devices have attracted much attention in the fields of new display technologies and new lighting technologies. At present, this technology has been widely used in display panels of new lighting fixtures, smart phones, tablet computers and other products, and will further expand to the application fields of large-size display products such as televisions. It is a new display technology that is developing rapidly and has high technical requirements.

[0003] In order to improve device efficiency, OLED devices are often prepared using a dual-host method for the light-emitting layer. Although this improves the luminous efficiency to a certain extent, it also increases the use of evaporation sources, making preparation slightly more difficult and limiting the commercial development of OLEDs.

[0004] In OLED devices, it is known that hole transport is generally faster than electron transport, and the recombination area in the light-emitting layer will be biased towards the ET layer, resulting in adverse consequences such as reduced device efficiency; although the increase in the thickness of the hole transport layer slows down the transmission of holes to the cathode, it increases the voltage of the device. At the same time, the energy level barrier between different material layers causes a large amount of positive and negative charge carriers to accumulate at their respective interfaces, which also causes reduced device efficiency.

[0005] In recent years, people in the industry have been constantly trying and exploring to improve device efficiency and stability. Among them, seeking new materials to improve device performance is the most common way. A large number of novel materials have been developed for use in electron transmission. Although there has been some improvement in device performance, there is still a large amount of carrier accumulation at the interface. There are also problems with high device voltage and short life. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, the present invention aims to improve the performance of organic electroluminescent devices by providing an organic electroluminescent device utilizing a novel functional material solution. The introduction of the novel electron-assisted layer of the present invention significantly improves carrier transport efficiency within the device, lowers energy barriers, and effectively reduces carrier accumulation at the interfaces between material layers, resulting in lower device voltage while also improving efficiency and lifetime.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] An organic electroluminescent device comprises an anode, a cathode, and one or more organic layers located between the anode and the cathode, wherein the organic layers comprise a light-emitting layer and an electron-assisting layer, wherein the electron-assisting layer is located between the light-emitting layer and the cathode, and wherein the electron-assisting layer comprises a compound represented by the following formula (1):

[0009]

[0010] In formula (1): L is selected from substituted or unsubstituted C6-C 30 arylene;

[0011] Further, when L is selected from substituted arylene, the substituent is preferably C3-C 30 heteroaryl;

[0012] R 1 、R 2 and R 3 are independently selected from hydrogen, cyano, substituted or unsubstituted C1-C 10 Alkyl or cycloalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 heteroaryl;

[0013] Ar is an electron-withdrawing group, preferably a substituent group represented by the following formula (A):

[0014]

[0015] In formula (A), X 1 -X 6 Each independently selected from nitrogen atoms, CH or CR, and at least one of them is a nitrogen atom, and the R is independently selected from C1-C 10 Alkyl, C1-C 10 Alkoxy, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups;

[0016] When the above groups have substituents, the substituents are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed-ring heteroaromatic hydrocarbon groups.

[0017] Furthermore, the general formula (1) is preferably the following structural formula (1-1), (1-2), (1-3) or (1-4):

[0018]

[0019] In formulas (1-1), (1-2), (1-3) and (1-4), R 1 、R 2 、R 3 and L are defined as in formula (1);

[0020] R 4 Selected from hydrogen, cyano, substituted or unsubstituted C1-C 10 Alkyl or cycloalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 The heteroaryl, the substituent groups are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed-ring heteroaromatic hydrocarbon groups; m is zero to the maximum allowed integer value.

[0021] Furthermore, the above R 1 to R 4Each of the following substituents is independently selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, triphenylenyl, pyrenyl, chrysene, peryl, fluoranthenyl, tetracenyl, pentacene, benzopyrenyl, biphenyl, aphenylene, terphenyl, triphenylene, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthrenyl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, spiroistrimerized indenyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indenocarbazolyl, pyridinyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthioimidazolyl, phenanthroimidazolyl, pyridimidazole 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthroline, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthroline, 1,2, 3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl, or a combination of two of the above groups.

[0022] Furthermore, the compounds of the general formula (1) of the present invention can preferably include the following specific structural compounds: C1-C164, which are only representative:

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] Further preferably, in the organic electroluminescent device of the present invention, the organic layer further comprises an electron transport layer, the electron transport layer being located between the electron auxiliary layer and the cathode, the electron transport layer comprising a compound selected from the above general formula (1), or the electron transport layer comprising any one compound selected from the following formulas ET-1 to ET-52:

[0032]

[0033]

[0034]

[0035] Further preferably, in the organic electroluminescent device of the present invention, the organic layer further comprises an electron transport layer, the electron transport layer being located between the electron auxiliary layer and the cathode. The electron transport layer comprises a compound selected from the compound represented by the general formula (1) above, or the host material is selected from a compound represented by any one of the formulas ET-1 to ET-52 above.

[0036] Further preferably, in the organic electroluminescent device of the present invention, the electron transport layer is composed of a host material and a dopant material, the dopant material is Liq, the host material is selected from the compound represented by the above general formula (1), or the host material is selected from the compound represented by any one of the above formulas ET-1 to ET-52.

[0037] More preferably, in the organic electroluminescent device of the present invention, the thickness of the electron auxiliary layer is 1 to 20 nm, preferably 5 to 10 nm.

[0038] More preferably, in the organic electroluminescent device of the present invention, the thickness of the electron transport layer is 10 to 50 nm, preferably 20 to 30 nm.

[0039] Further preferably, in the organic electroluminescent device of the present invention, the host material and the doping material in the electron transport layer are prepared by a dual-source co-evaporation process.

[0040] Further preferably, in the organic electroluminescent device of the present invention, the ratio of the host material to the dopant material in the electron transport layer is 1:0.1 to 1:2, and preferably 1:1.0 to 1:1.5.

[0041] Further preferably, in the organic electroluminescent device of the present invention, the organic layer further comprises a hole transport layer and / or a hole injection layer located between the light-emitting layer and the anode.

[0042] The organic electroluminescent device of the present invention uses a specific structural compound such as the general formula (1) as the electron-assisting layer in the device, which not only facilitates the injection of electrons from the cathode into the light-emitting layer, but also effectively balances the number of carriers in the device and effectively improves the recombination efficiency of the carriers. In a more preferred embodiment of the present invention, the electron-assisting layer is combined with an electron transport layer composed of the compound represented by the general formula (1) and a specific dopant material. This further optimizes the performance of the device, significantly improves the luminous efficiency of the device, and also reduces the device energy level barrier, thereby reducing the voltage of the organic electroluminescent device. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the structure of the organic electroluminescent device according to an embodiment of the present invention;

[0044] Figure 1 In the figure, 1 is the anode; 2 is the hole transport layer; 3 is the light-emitting layer; 4 is the electron auxiliary layer; 5 is the electron transport layer; and 6 is the cathode. DETAILED DESCRIPTION

[0045] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The present invention is not limited to the following embodiments, but is merely an illustrative embodiment of the present invention.

[0046] The organic electroluminescent device of the present invention is fabricated using vacuum evaporation, but other methods are also possible, not limited to vacuum deposition. This invention illustrates devices fabricated using vacuum deposition. The substrate is cleaned, post-baked, pretreated, and placed in the cavity. The hole injection layer, hole transport layer, light-emitting layer, electron assist layer, electron transport layer, and cathode are then vacuum deposited in sequence.

[0047] The substrate can be a rigid substrate or a flexible substrate. Rigid substrates include glass substrates, Si substrates, etc. Flexible substrates include polyvinyl alcohol (PVA) films, polyimide (PD) films, polyester (PET) films, etc. The substrate of the present invention is preferably a rigid glass substrate.

[0048] The anode is preferably a conductive compound, alloy, metal, or mixture of such materials having a relatively high work function. Inorganic materials can be used, including metal oxides such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), and tin oxide (SnO), or metals with relatively high work functions such as gold, silver, copper, and aluminum, or alternating layers of metals with metals or non-metals. ITO is preferred for the anode of the present invention.

[0049] The hole transport region includes a hole transport layer and / or a hole injection layer. The specific material can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-34 below, or any combination thereof.

[0050]

[0051]

[0052] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0053]

[0054] The fluorescent dopant of the light-emitting layer is selected from one of BFD-1 to BFD-12:

[0055]

[0056] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0057]

[0058]

[0059]

[0060]

[0061] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0062]

[0063]

[0064]

[0065] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of RH-1 to RH-31.

[0066]

[0067]

[0068] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0069]

[0070]

[0071] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0072]

[0073] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence, and the fluorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of TDE1-TDE39 listed below.

[0074]

[0075]

[0076]

[0077] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of TDH-1 to TDH-24.

[0078]

[0079]

[0080]

[0081] In the organic electroluminescent device of the present invention, the electron auxiliary layer is selected from the material of the above general formula (1), wherein some representative compounds of the general formula (1) are synthesized and prepared as follows:

[0082] Synthesis method of compound C4:

[0083] The synthetic route is as follows:

[0084]

[0085] Preparation of compound 1-1

[0086] To a single-necked flask, add 2-amino-5-bromopyrazine (17.3 g, 100 mmol), phenanthreneboric acid (22.2 g, 1000 mmol), potassium carbonate (41.4 g, 300 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (0.73 g, 1 mmol). Add 300 mL of tetrahydrofuran and 60 mL of water. Under nitrogen, reflux at 80°C overnight. Solid precipitates during the reaction. TLC confirms the reaction is complete. Stop the reaction, cool to room temperature, filter the precipitated solid, rinse with water and ethanol, and dry. This yields the target compound 1-1 (24.4 g, 90% yield).

[0087] Preparation of compound 1-2

[0088] Intermediate compound 1-1 (22.6 g, 83.33 mmol) was added to a flask containing DCM (100 mL). The mixture was cooled to 0°C and slowly added dropwise with ethoxycarbonyl isothiocyanate (10.92 g, 83.33 mmol). The reaction mixture was warmed to room temperature and stirred for 20 h. The solvent was removed by vacuum distillation and filtered. After drying with warm air, the desired product 1-2 (31.2 g, 93% yield) was obtained.

[0089] Preparation of Compounds 1-3

[0090] Hydroxylamine hydrochloride (23.29 g, 337.58 mmol) was added to ethanol (200 ml), and triethylamine (22.73 g, 225.06 mmol) was added to the reaction solution and stirred for 1 hour. The above-synthesized 1-2 (30.2 g, 75.02 mmol) was added, the temperature was slowly increased, and the reaction mixture was heated under reflux for 3 hours. The mixture was cooled to room temperature and the solid was filtered. The solid products were combined, washed with distilled water, ethanol and n-hexane, and dried with warm air to obtain the target compound 1-3 (21 g, yield 90%).

[0091] Preparation of Compounds 1-4

[0092] To the compound 1-3 (12.6 g, 40.51 mmol) synthesized above, copper bromide (2.71 g, 12.15 mmol) and tetrahydrofuran (100 ml) were added. The reaction solution was cooled to 0°C, hydrobromic acid (80 ml) was slowly added dropwise, and sodium nitrite (8.39 g, 121.53 mmol) was dissolved in distilled water (30 ml) and slowly added dropwise. The reaction solution was stirred at room temperature for 12 h. Aqueous sodium hydroxide solution (50 ml) was added to the reaction solution, stirred for 1 h, and the mixture was extracted with ethyl acetate, washed with water, and the organic phase was dried, distilled under reduced pressure, and purified by silica gel column chromatography to obtain the target product 1-4 (9.85 g, yield 65%).

[0093] Preparation of compound C4

[0094] Compound 1-4 (9.1 g, 24.31 mmol) and 2-(4-boronic acid ester)phenyl-4,6-diphenyl-1,3,5-triazine (10.57 g, 24.31 mmol) were added to a three-necked flask, and potassium carbonate (10.06 g, 72.93 mmol) was dissolved in 30 mL of water and added to the three-necked flask. 150 mL of tetrahydrofuran was added, and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (0.53 g, 0.73 mmol) was added to replace nitrogen three times. The mixture was heated in an oil bath to 80°C for 4 to 5 hours. The reaction was completed after monitoring by TLC. The reaction mixture was cooled to room temperature and extracted with ethyl acetate. The organic phases were combined, dried, and concentrated. Dissolved in DCM, column chromatography was performed, and the product was collected and concentrated. Dissolved in toluene at 120°C, and then slowly added with ethanol equal in volume to the toluene. Stirring was continued for 0.5 h. Heating was stopped and the mixture was allowed to cool naturally to room temperature. After sufficient precipitation of the product, the product was filtered and dried to obtain Compound C4 (10.4 g, 71% yield) as a white solid. Calculated molecular weight: 603.22, measured C / Z: 603.2.

[0095] Synthesis of compound C35:

[0096] The synthetic route is as follows:

[0097]

[0098] This was synthesized using a similar method to C4. The differences were that 2-amino-3,5-dibromopyrazine was used in place of 2-amino-5-bromopyrazine in the first step, and phenylboronic acid was used in place of 9-phenanthreneboronic acid in the Suzuki reaction to synthesize intermediate 3-1. A similar synthesis method was used to obtain compound C35, a white solid with a calculated molecular weight of 579.22 and a measured C / Z of 579.2.

[0099] Synthesis of compound C51:

[0100] The synthetic route is as follows:

[0101]

[0102] Synthesis of intermediate 6-2

[0103] Compound 6-1 (38.7 g, 0.1 mol), 3-chlorophenylboronic acid (17.2 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). The atmosphere was replaced with nitrogen while stirring at room temperature, and Pd(PPh3)4 (1.15 g, 0.001 mol) was added. After addition, the mixture was stirred and refluxed for 4 hours, and the reaction endpoint was monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was rinsed sequentially with toluene, water, and ethanol, and air-dried. Compound 6-2 (38.1 g, 91% yield) was obtained by column chromatography.

[0104] Preparation of compound 6-3

[0105] Compound 6-2 (33.5 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After nitrogen displacement with stirring at room temperature, Pd2(dba)3 (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. After the addition was complete, the mixture was stirred and refluxed for 24 hours. The reaction endpoint was monitored by TLC. The precipitated solid was filtered, washed with water, and dried to obtain compound 6-3 (32.7 g, 80% yield).

[0106] Synthesis of compound C51

[0107] A similar synthesis method to C35 was used to synthesize the compound. The difference was that in the fifth step, intermediate 6-3 was used instead of 2-(4-boronic acid ester)phenyl-4,6-diphenyl-1,3,5-triazine. A white solid compound C51 was obtained by a similar synthesis method. The calculated molecular weight was 655.25 and the measured C / Z was 655.3.

[0108] Synthesis of compound C94:

[0109] The synthetic route is as follows:

[0110]

[0111] Synthesis of intermediate 8-1

[0112] 2-Chloro-4-phenylquinazoline (24 g, 0.1 mol), 4-chlorophenylboronic acid (17.2 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). The atmosphere was replaced with nitrogen while stirring at room temperature, and Pd(PPh3)4 (1.15 g, 0.001 mol) was added. After addition, the mixture was stirred and refluxed for 4 hours, and the reaction endpoint was monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was rinsed sequentially with toluene, water, and ethanol, and air-dried. Compound 8-1 was purified by column chromatography to obtain 29 g, 92% yield.

[0113] Preparation of compound 8-2

[0114] Compound 8-1 (25.3 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After nitrogen displacement with stirring at room temperature, Pd2(dba)3 (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. After the addition was complete, the mixture was stirred and refluxed for 24 hours. The reaction endpoint was monitored by TLC. The precipitated solid was filtered, washed with water, and dried to obtain compound 8-2 (26.4 g, 81% yield).

[0115] Synthesis of compound C94

[0116] The synthesis method was similar to that of C4, except that intermediate 8-2 was used in the fifth step instead of 2-(4-boronic acid ester)phenyl-4,6-diphenyl-1,3,5-triazine. A white solid compound C94 was obtained by a similar synthesis method with a calculated molecular weight of 576.21 and a measured C / Z of 576.2.

[0117] The organic electroluminescent device preparation process in the embodiment of the present invention is as follows:

[0118] Comparative Example 1-1

[0119] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0120] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0121] The light-emitting layer of the device is vacuum evaporated on top of the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.005nm / s, and the total evaporation film thickness is 20nm.

[0122] The electron transport layer material ET-1:Liq of the device was vacuum evaporated on the light-emitting layer. The evaporation rate of ET-1 and Liq was 0.1nm / s, and the total film thickness was 23nm.

[0123] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0124] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / ET-1:100%Liq(23) / Mg:Ag(150)

[0125] Comparative Example 1-2

[0126] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0127] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0128] The light-emitting layer of the device was vacuum-evaporated on top of the hole transport layer. The light-emitting layer included the host material BFH-1 and the dye BFD-1. The multi-source co-evaporation method was used. The host material rate was 0.1nm / s, the dye rate was 0.005nm / s, and the total film thickness was 20nm.

[0129] The hole blocking layer material ET-2 of the device is vacuum evaporated on the light-emitting layer at a rate of 0.1 nm / s and a film thickness of 5 nm.

[0130] The electron transport layer material ET-1 of the device is vacuum evaporated on the hole blocking layer: 100% Liq. The ET-1 evaporation rate is 0.1 nm / s and the total evaporation film thickness is 23 nm.

[0131] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0132] Device structure:

[0133] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / ET-2(5) / ET-1:100%Liq(23) / Mg:Ag(150)

[0134] Example 1-1

[0135] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0136] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0137] The light-emitting layer of the device is vacuum evaporated on top of the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.005nm / s, and the total evaporation film thickness is 20nm.

[0138] The electronic auxiliary layer material C4 of the device is vacuum evaporated on the light-emitting layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 1 nm.

[0139] The electron transport layer material ET-1 of the device is vacuum evaporated on the electron auxiliary layer: 100% Liq, the ET-1 evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 23 nm;

[0140] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0141] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(1) / ET-1:100%Liq(23) / Mg:Ag(150)

[0142] Example 1-2

[0143] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0144] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0145] The light-emitting layer of the device is vacuum evaporated on top of the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.005nm / s, and the total evaporation film thickness is 20nm.

[0146] The electronic auxiliary layer material C4 of the device is vacuum evaporated on the light-emitting layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 3 nm.

[0147] The electron transport layer material ET-1 of the device is vacuum evaporated on the electron auxiliary layer: 100% Liq, the ET-1 evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 23 nm;

[0148] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0149] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(3) / ET-1:100%Liq(23) / Mg:Ag(150)

[0150] Examples 1-3

[0151] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0152] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0153] The light-emitting layer of the device is vacuum evaporated on top of the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.005nm / s, and the total evaporation film thickness is 20nm.

[0154] The electronic auxiliary layer material C4 of the device is vacuum evaporated on the light-emitting layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 5 nm.

[0155] The electron transport layer material ET-1 of the device is vacuum evaporated on the electron auxiliary layer: 100% Liq, the ET-1 evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 23 nm;

[0156] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0157] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / ET-1:100%Liq(23) / Mg:Ag(150)

[0158] Examples 1-4

[0159] The preparation method is consistent with that of Example 1-2, except that the thickness of the electron auxiliary layer is 7 nm.

[0160] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(7) / ET-1:100%Liq(23) / Mg:Ag(150)

[0161] Examples 1-5

[0162] The preparation method is consistent with that of Example 1-2, except that the thickness of the electron auxiliary layer is 10 nm.

[0163] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(10) / ET-1:100%Liq(23) / Mg:Ag(150)

[0164] Examples 1-6

[0165] The preparation method is consistent with that of Example 1-2, except that the thickness of the electron auxiliary layer is 15 nm.

[0166] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(15) / ET-1:100%Liq(23) / Mg:Ag(150)

[0167] Examples 1-7

[0168] The preparation method is consistent with that of Example 1-2, except that the thickness of the electron auxiliary layer is 20 nm.

[0169] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(20) / ET-1:100%Liq(23) / Mg:Ag(150)

[0170] Examples 1-8

[0171] The preparation method is consistent with that of Example 1-3, except that the material of the electron auxiliary layer is C51.

[0172] Device structure:

[0173] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C51(5) / ET-1:100%Liq(23) / Mg:Ag(150)

[0174] Examples 1-9

[0175] The preparation method is consistent with that of Example 1-3, except that the material of the electron auxiliary layer is C94.

[0176] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C94(5) / ET-1:100%Liq(23) / Mg:Ag(150)

[0177] Device testing method: The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0178] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the Examples and Comparative Examples were measured using a Photo Research PR 750 radiometer and ST-86LA luminance meter (Beijing Normal University Photoelectric Instrument Factory) and a Keithley 4200 test system. Specifically, the voltage was increased at a rate of 0.1 V per second, and the voltage at which the brightness of the organic electroluminescent device reached 1000 cd / m2 was measured, i.e., the driving voltage. The current density at this point was also measured. The ratio of the brightness to the current density was the current efficiency. The LT95 lifespan test was performed as follows: Using the luminance meter, at a brightness of 3000 cd / m2, while maintaining a constant current, the time (in hours) for the brightness of the organic electroluminescent device to drop to 2850 cd / m2 was measured.

[0179] The devices prepared in Examples 1-1 to 1-7 and Comparative Examples 1-1 and 1-2 were tested. The specific materials used in the light-emitting layer and the performance results of the prepared devices are shown in Table 1 below:

[0180] Table 1:

[0181]

[0182] As can be seen from the contents of Table 1 above, the overall performance of the device prepared by using the compound represented by general formula (1) of the present invention as the electronic auxiliary layer of the device is significantly improved compared with the performance of the device prepared in the comparative example using the device material solution of the prior art. In particular, the device efficiency is significantly improved, and when the thickness of the electronic auxiliary layer is 5-10 nm, the device performance is optimal.

[0183] Example 2-1

[0184] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0185] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0186] The light-emitting layer of the device is vacuum-deposited on the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.005nm / s, and the total film thickness is 20nm.

[0187] The electronic auxiliary layer material C4 of the device is vacuum evaporated on the light-emitting layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 5 nm.

[0188] The electron transport layer of the device is vacuum-deposited on the electron auxiliary layer. The materials used are C51 as the main material and Liq as the dopant material. The evaporation rate of C51 and Liq is 0.1nm / s, and the total film thickness is 10nm.

[0189] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0190] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(10) / Mg:Ag(150)

[0191] Example 2-2

[0192] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 15 nm.

[0193] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(15) / Mg:Ag(150)

[0194] Example 2-3

[0195] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 23 nm.

[0196] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(23) / Mg:Ag(150)

[0197] Examples 2-4

[0198] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 25 nm.

[0199] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(25) / Mg:Ag(150)

[0200] Examples 2-5

[0201] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 30 nm.

[0202] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(30) / Mg:Ag(150)

[0203] Examples 2-6

[0204] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 40 nm.

[0205] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(40) / Mg:Ag(150)

[0206] Examples 2-7

[0207] The preparation method of this embodiment is exactly the same as that of embodiment 2-1, except that the thickness of the ETL layer is 50 nm.

[0208] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:100%Liq(50) / Mg:Ag(150)

[0209] Examples 2-8

[0210] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that the evaporation rate ratio C51:Liq in the ETL layer is 1:0.1.

[0211] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:10%Liq(23) / Mg:Ag(150)

[0212] Examples 2-9

[0213] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that the evaporation rate ratio C51:Liq in the ETL layer is 1:0.5.

[0214] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:50%Liq(23) / Mg:Ag(150)

[0215] Example 2-10

[0216] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that the evaporation rate ratio C51:Liq in the ETL layer is 1:1.2.

[0217] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:120%Liq(23) / Mg:Ag(150)

[0218] Example 2-11

[0219] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that the evaporation rate ratio C51:Liq in the ETL layer is 1:1.5.

[0220] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:150%Liq(23) / Mg:Ag(150)

[0221] Example 2-12

[0222] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that the evaporation rate ratio C51:Liq in the ETL layer is 1:2.

[0223] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51:200%Liq(23) / Mg:Ag(150)

[0224] Example 2-13

[0225] The preparation method of this embodiment is exactly the same as that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 1 nm.

[0226] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(1) / C51:120%Liq(23) / Mg:Ag(150)

[0227] Examples 2-14

[0228] The preparation method of this embodiment is exactly the same as that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 3 nm.

[0229] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(3) / C51:120%Liq(23) / Mg:Ag(150)

[0230] Example 2-15

[0231] The preparation method of this embodiment is completely consistent with that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 7 nm.

[0232] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(7) / C51:120%Liq(23) / Mg:Ag(150)

[0233] Example 2-16

[0234] The preparation method of this embodiment is exactly the same as that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 10 nm.

[0235] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(10) / C51:120%Liq(23) / Mg:Ag(150)

[0236] Example 2-17

[0237] The preparation method of this embodiment is completely consistent with that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 15 nm.

[0238] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(15) / C51:120%Liq(23) / Mg:Ag(150)

[0239] Example 2-18

[0240] The preparation method of this embodiment is completely consistent with that of embodiment 2-8, except that the thickness of the electron auxiliary layer is 20 nm.

[0241] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(20) / C51:120%Liq(23) / Mg:Ag(150)

[0242] Example 2-19

[0243] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that C4 in the electron auxiliary layer is replaced by C51.

[0244] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C51(5) / C51:100%Liq(23) / Mg:Ag(150)

[0245] Example 2-20

[0246] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that C51 in ETL is replaced by C4.

[0247] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C4:100%Liq(23) / Mg:Ag(150)

[0248] Example 2-21

[0249] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that C51 in the ETL layer is replaced by C94.

[0250] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C94:100%Liq(23) / Mg:Ag(150)

[0251] Example 2-22

[0252] The preparation method of this embodiment is exactly the same as that of embodiment 2-13, except that C4 in the electron auxiliary layer is replaced by C51.

[0253] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C51(5) / C94:100%Liq(23) / Mg:Ag(150)

[0254] Example 2-23

[0255] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that only C51 is used in ETL.

[0256] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / C51(23) / Mg:Ag(150)

[0257] Examples 2-24

[0258] The preparation method of this embodiment is exactly the same as that of embodiment 2-3, except that only Alq3 is used in the ETL.

[0259] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / C4(5) / Alq3(23) / Mg:Ag(150)

[0260] Comparative Example 2-1

[0261] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0262] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, HT1 was vacuum evaporated on the above anode layer as the hole transport layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0263] The light-emitting layer of the device is vacuum-deposited on the hole transport layer. The light-emitting layer includes the main material BFH-1 and the dye BFD-1. The multi-source co-evaporation method is used. The main material rate is 0.1nm / s, the dye rate is 0.05nm / s, and the total film thickness is 20nm.

[0264] The hole blocking layer material ET-2 of the device is vacuum evaporated on the light-emitting layer with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 6 nm.

[0265] The electron transport layer material Alq3 of the device is deposited on the hole blocking layer at a deposition rate of 0.1 nm / s and a total deposition thickness of 23 nm.

[0266] A 150 nm thick Mg / Ag layer was vacuum evaporated on the electron transport layer (ETL) as the cathode of the device.

[0267] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / ET-2(5) / Alq3(23) / Mg:Ag(150)

[0268] The devices prepared in the above embodiments and comparative examples were tested, and the specific conditions of the materials used in the light-emitting layer and the performance results of the prepared devices are shown in Table 2 below.

[0269] Table 2:

[0270]

[0271] As can be seen from the contents of Table 2 above, the use of the compound represented by the general formula (1) of the present invention for the electron-assisted layer of the device, and the general formula combined with the electron transport layer composed of the compound represented by the present invention (1) and Liq doping, the overall performance of the prepared device is significantly improved compared with the performance of the device prepared in the comparative example using the device material solution of the prior art, and when the thickness of the electron-assisted layer is 5-10 nm, the thickness of the ETL is 20 to 30 nm, and the doping ratio is 1:1 to 1:1.5, the device performance is optimal.

[0272] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. An organic electroluminescent device comprising an anode, a cathode, and one or more organic layers located between the anode and the cathode, characterized in that: The organic layer includes a light-emitting layer and an electron-assisting layer, wherein the electron-assisting layer is located between the light-emitting layer and the cathode, and further includes an electron-transporting layer, wherein the electron-transporting layer is located between the electron-assisting layer and the cathode, and the electron-assisting layer includes a compound represented by the following formula (1-1), (1-2), (1-3) or (1-4); The electron transport layer is composed of a main material and a dopant material, the dopant material is Liq, and the main material is selected from the compounds represented by the following formula (1-1), (1-2), (1-3) or (1-4); In formula (1): L is selected from substituted or unsubstituted C6-C 30 arylene; R 1 、R 2 and R 3 are independently selected from hydrogen, cyano, substituted or unsubstituted C1-C 10 Alkyl or cycloalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 heteroaryl; R 4 Selected from hydrogen, cyano, substituted or unsubstituted C1-C 10 Alkyl or cycloalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 The heteroaryl, the substituent groups are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed ring heteroaromatic hydrocarbon groups; m is zero to the maximum allowed integer value; when the above groups have substituents, the substituents are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed-ring heteroaromatic hydrocarbon groups.

2. The organic electroluminescent device according to claim 1, wherein When L is selected from substituted arylene, the substituent is cyano or C3-C 30 of heteroaryl.

3. The organic electroluminescent device according to claim 1, wherein The compound is selected from any one of the following compounds C1-C164:

4. The organic electroluminescent device according to claim 1, wherein The ratio of the main material to the doping material in the electron transport layer is 1:0.1 to 1:

2.

5. The organic electroluminescent device according to claim 4, characterized in that: The ratio of the main material to the doping material in the electron transport layer is 1:1.0 to 1:1.

5.

6. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that: The thickness of the electron auxiliary layer is 1 to 20 nm, and the thickness of the electron transport layer is 10 to 50 nm.

7. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that: The thickness of the electron auxiliary layer is 5-10 nm, and the thickness of the electron transport layer is 20-30 nm.

8. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that: The organic layer further includes a hole transport layer and / or a hole injection layer located between the light emitting layer and the anode.

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