Nitrogen heterocyclic organic compound, application thereof and organic electroluminescent device

Abstract

The invention relates to the technical field of organic light-emitting devices, and discloses a nitrogen heterocyclic organic compound, application thereof and an organic light-emitting device, and the compound has a structure as shown in a formula (I). When the nitrogen heterocyclic organic compound provided by the invention is applied to the organic light-emitting device, the organic light-emitting device containing the nitrogen heterocyclic organic compound has the advantages of low driving voltage, high light-emitting efficiency and long service life. # imgabs0 #

Description

Technical Field

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

[0002] Organic Light Emission Diodes (OLED) is a display technology with broad application prospects. OLED has the characteristics of self-luminescence and does not require a backlight, which gives it significant advantages in terms of contrast and color performance. At the same time, it is also thin and bendable, and has gradually become one of the mainstream display technologies.

[0003] At present, a stacked organic electroluminescent device has received extensive attention. The luminescence principle is the same as that of the traditional single-layer OLED device. The single-layer OLED device is a light-emitting unit, which usually includes a light-emitting layer and a matching electron transport layer and hole transport layer. When a voltage is applied to both ends of the device: under the action of an external electric field, the electrodes inject electrons and holes, and electrons enter the light-emitting layer from the cathode through the electron transport layer, and holes also enter the light-emitting layer from the anode through the hole transport layer. In the light-emitting layer, electrons and holes meet and recombine to form excitons, and when the excitons transition from the excited state back to the ground state, they radiate photons, thereby generating light. For a stacked structure, multiple such light-emitting units are stacked together, and the light generated by the previous light-emitting unit can reach the next unit through the middle charge generation layer (CGL, Charge Generation Layer). It is composed of multiple organic light-emitting layers stacked together. Through the light-emitting combination of different light-emitting layers, light emission of various colors and spectra can be achieved, and at the same time, higher light-emitting efficiency, color purity, brightness and service life are achieved.

[0004] In a stacked device, the main function of CGL is to generate holes and electrons under the action of an electric field, provide the required charges for the light-emitting layer, and effectively transfer the generated charges to the adjacent light-emitting layer to ensure uniform distribution of charges in the device.

[0005] Therefore, the performance of the CGL layer has a crucial impact on the performance of the entire stacked device. In addition, the CGL material needs to have good charge transport properties, optical transmittance and stability to ensure the effective transfer and collection of charges between light-emitting units while reducing energy loss.

[0006] In summary, it is of great significance to develop high-performance CGL materials to reduce the energy level barrier between the light-emitting unit transmission and improve the energy level matching between the CGL layer and the light-emitting unit, thereby reducing the driving voltage of the device and improving the luminous efficiency and service life of the device. Summary of the invention

[0007] The purpose of the present invention is to provide a new type of nitrogen heterocyclic organic compound so that an organic light-emitting device containing the new type of nitrogen heterocyclic organic compound has the advantages of low driving voltage, high luminous efficiency and long service life.

[0008] In order to achieve the above object, the first aspect of the present invention provides a nitrogen heterocyclic organic compound having a structure shown in formula (I):

[0009] Wherein, in formula (I), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 Any 1 to 4 of them are deuterium, and the remaining groups are hydrogen.

[0010] The second aspect of the present invention provides use of the nitrogen heterocyclic organic compound described in the first aspect in an organic electroluminescent device and / or a perovskite solar cell.

[0011] The third aspect of the present invention provides an organic electroluminescent device, which comprises a first electrode; a second electrode arranged opposite to the first electrode; and at least two light-emitting units arranged between the first electrode and the second electrode, wherein the charge generation layer between any two adjacent light-emitting units contains at least one of the nitrogen heterocyclic organic compounds described in the first aspect.

[0012] The deuterated nitrogen heterocyclic organic compound provided by the present invention has suitable HOMO energy level and LUMO energy level, and can well match the HOMO and LUMO energy levels of adjacent functional layers, thereby reducing the driving voltage of the device; the deuterated nitrogen heterocyclic organic compound provided by the present invention has high electron mobility, that is, strong electron transmission ability, and when the compound of the present invention is applied to an organic electroluminescent device, the luminous efficiency of the device can be improved; the deuterated nitrogen heterocyclic organic compound of the present invention has a high glass transition temperature, and can make the thermal stability of the film good; the deuterated nitrogen heterocyclic organic compound of the present invention has a heavy atom effect, and can improve the service life of the device.

[0013] In addition, the compounds provided by the present invention have a suitable amount of deuterated substituents at specific positions, which can enhance the electron transition ability, and will not accelerate the diffusion of n-type dopants such as alkali metals or alkaline earth metals into the p-CGL layer under the action of an external electric field due to too strong transition ability, thereby affecting the overall performance of the device.

[0014] In summary, when the nitrogen heterocyclic organic compound provided by the present invention is used in an organic light-emitting device, the organic light-emitting device containing such nitrogen heterocyclic organic compound has the advantages of low driving voltage, high luminous efficiency and long service life. DETAILED DESCRIPTION

[0015] 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.

[0016] As mentioned above, the first aspect of the present invention provides a nitrogen heterocyclic organic compound having a structure shown in formula (I):

[0017] Wherein, in formula (I), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 Any 1 to 4 of them are deuterium, and the remaining groups are hydrogen.

[0018] According to a first preferred embodiment, in formula (I), R 11 and / or R 17 The remaining groups are hydrogen.

[0019] In the aforementioned first preferred embodiment, more preferably, the structure represented by formula (I) is selected from any one of the following:

[0020] According to a second preferred embodiment, in formula (I), R 14 and / or R 15 The remaining groups are hydrogen.

[0021] In the aforementioned second preferred embodiment, more preferably, the structure represented by formula (I) is the following structure:

[0022] According to a third preferred embodiment, in formula (I), R 11 and / or R 17 is deuterium, R 14 and R 15The remaining groups are hydrogen.

[0023] In the aforementioned third preferred embodiment, more preferably, the structure represented by formula (I) is selected from any one of the following:

[0024] According to a fourth preferred embodiment, the structure represented by formula (I) is selected from any one of the following:

[0025] The present invention has no particular limitation on the specific method for preparing the aforementioned organic 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 known knowledge in the field of organic synthesis. In addition, several examples are exemplarily listed in the following text of the present invention to illustrate the preparation method of the organic compounds of the present invention. Those skilled in the art can also obtain the specific preparation method of all other organic compounds by replacing the types of raw materials according to the preparation method of the organic compounds in the following text of the present invention. The present invention no longer describes in detail the preparation methods of all organic compounds, and those skilled in the art should not be construed as limiting the present invention.

[0026] As mentioned above, the second aspect of the present invention provides the use of the nitrogen heterocyclic organic compound described in the first aspect in an organic electroluminescent device and / or a perovskite solar cell.

[0027] Preferably, the nitrogen heterocyclic organic compound is contained in the charge generation layer and / or the electron transport layer of the organic electroluminescent device.

[0028] The organic electroluminescent device of the present invention may be a single-layer organic electroluminescent device or a stacked organic electroluminescent device.

[0029] According to a preferred embodiment, the organic electroluminescent device is a single-layer organic electroluminescent device (ie, there is a light-emitting unit between two electrodes), wherein the electron transport layer contains the nitrogen heterocyclic organic compound.

[0030] According to another preferred embodiment, the organic electroluminescent device is a stacked organic electroluminescent device (ie, there are at least two light-emitting units between two electrodes), wherein the charge generation layer contains the nitrogen heterocyclic organic compound.

[0031] As mentioned above, the third aspect of the present invention provides an organic electroluminescent device, which comprises a first electrode; a second electrode arranged opposite to the first electrode; and at least two light-emitting units arranged between the first electrode and the second electrode, and the charge generation layer between any two adjacent light-emitting units contains at least one of the nitrogen heterocyclic organic compounds described in the first aspect of the present invention.

[0032] Preferably, each of the light-emitting units contains a light-emitting layer, a hole transport layer and an electron transport layer.

[0033] More preferably, each of the light-emitting units further comprises a hole injection layer, an electron blocking layer, a hole blocking layer and an electron injection layer.

[0034] Preferably, the charge generation layer contains an n-type doping body and a p-type doping body, and the n-type doping body contains at least one of the nitrogen heterocyclic organic compounds.

[0035] According to a preferred embodiment, the p-type doping body contains at least one of the following compounds:

[0036]

[0037] Preferably, the nitrogen heterocyclic organic compound exists in the CGL layer between the light-emitting units of the stacked organic electroluminescent device.

[0038] More preferably, the stacked organic electroluminescent device contains a CGL layer, and the CGL layer contains an n-type doping layer and a p-type doping layer. The energy level difference between the LUMO energy level of the material of the n-type doping layer and the HOMO energy level of the material of the p-type doping layer of the present invention is small, and carriers can be generated at a lower driving voltage.

[0039] Preferably, the n-type doping layer is composed of an n-type doping body and an n-type dopant, the p-type doping layer is composed of a p-type doping body and a p-type dopant, and the organic compound is an n-type doping body between light-emitting units in the stacked organic electroluminescent device.

[0040] Preferably, the n-type doping body is selected from at least one of the nitrogen heterocyclic organic compounds described in the first aspect of the present invention.

[0041] Preferably, the n-type dopant is selected from alkali metals, alkaline earth metals, transition metals or main group metals; more preferably, the n-type dopant is selected from one or a mixture of lithium, sodium, potassium, calcium, magnesium, gold, silver, ytterbium and aluminum.

[0042] The p-type dopant of the present invention is an organic semiconductor material with strong electron-withdrawing ability.

[0043] According to another preferred embodiment, the p-type dopant is selected from at least one of the following: HAT-CN, NPD-9, F4TCNQ, and F6TCNNQ:

[0044] More preferably, in the CGL layer, the weight ratio of the material of the n-type doping layer to the material of the p-type doping layer is 1:0.1-2; particularly preferably, the weight ratio of the material of the n-type doping layer to the material of the p-type doping layer is 1:0.5-1.

[0045] Preferably, based on the total amount of the n-type doping body, the content ratio of the n-type dopant is 0.2-20 wt %; particularly preferably, the content ratio of the n-type dopant is 1-10 wt %.

[0046] Preferably, based on the total amount of the p-type doping body, the content ratio of the p-type dopant is 0.2-20 wt %; particularly preferably, the content ratio of the p-type dopant is 1-10 wt %.

[0047] Preferably, the organic electroluminescent device of the present invention is coated with one or more layers by means of a sublimation method. In this case, in a vacuum sublimation system, at a temperature of less than 10 -3 Pa, preferably less than 10 -6 The organic compound provided by the present invention is applied by vapor deposition at an initial pressure of 1.5 Pa.

[0048] The organic electroluminescent device of the invention is preferably coated with one or more layers by an organic vapor deposition method or by means of carrier gas sublimation. -6 The material is applied at a pressure of 100 Pa to 100 Pa. A particular example of this method is an organic vapor deposition printing method, in which the compound provided by the present invention is directly applied through a nozzle and forms a device structure.

[0049] The organic electroluminescent device of the present invention is preferably formed into a single-layer or multi-layer structure by light-induced thermal imaging or thermal transfer.

[0050] The organic electroluminescent device of the present invention preferably prepares the organic compound of the present invention into a solution, and forms a layer or a plurality of layer structures by spin coating or by means of any printing method, such as screen printing, flexographic printing, inkjet printing, lithography, and more preferably inkjet printing. However, when multiple layers are made in this way, damage between layers is likely to occur, that is, when one layer is made, when another layer is made with a solution, the solvent in the solution will destroy the already formed layer, which is not conducive to device production. The organic compound provided by the present invention can be replaced by structural modification, so that the organic compound of the present invention undergoes cross-linking under heating or ultraviolet exposure, thereby maintaining a complete layer without being destroyed. The organic compound of the present invention can also be applied from a solution and fixed in the corresponding layer by subsequent cross-linking in a polymer network.

[0051] Preferably, the organic electroluminescent device of the invention is produced by applying one or more layers from solution and by applying one or more layers by a sublimation method.

[0052] Preferably, when preparing the organic electroluminescent device of the present invention, the organic compound of the present invention or other compounds are first fully mixed, and then applied in the above manner to form one or more layers. More preferably, in a vacuum sublimation system, at a temperature of less than 10 -3 Pa, preferably less than 10 -6 The compounds are applied by vapor deposition at an initial pressure of 1.3 Pa to form one or more layers.

[0053] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all raw materials used are common commercial products. Unless otherwise specified, the room temperature or normal temperature described below refers to 25±1°C.

[0054] The present invention provides methods for preparing some of the compounds in the following specific structural formulas. The methods for preparing the remaining compounds can be carried out by referring to the methods provided below, which should not be construed as limiting the present invention by those skilled in the art.

[0055]

[0056] Synthesis of intermediate 1-1-1: In a 500ml three-necked flask, under nitrogen protection, 2-bromo-1,10-phenanthroline (0.1mol), 1,4-phenylenediboronic acid (0.05mol), a mixed solution of toluene, ethanol, and water (toluene, ethanol, and water are mixed in a volume ratio of 3:2:1) (260ml) were added in sequence, and stirring began. Potassium carbonate (0.25mol) and tetrakis(triphenylphosphine)palladium (1mmol) were then added in sequence, and the temperature was raised to reflux for 6h. HPLC detected that the reaction of the raw materials was basically complete, and deionized water (350ml) was added to the reaction solution, stirred for 10min, and the organic phase was washed three times with water, combined with the organic phase, and dried over anhydrous magnesium sulfate. The desiccant was filtered, the organic solvent was spin-dried, and the residue was separated by silica gel chromatography to obtain intermediate 1-1-1 (yield: 68.6%).

[0057] Synthesis of compound 1-1: In a 500ml three-necked flask, under nitrogen protection, add intermediate 1-1-1 (34mmol) and THF (300ml), and start stirring. In a single-necked flask, add methanesulfonic anhydride (0.17mol) and heavy water (0.51mol) to prepare acid water in a molar ratio of 1:3, slowly add the acid water to the reaction system, heat to 80°C, react for 12 hours, stop heating, cool to room temperature, add 350ml of water, stand for 30 minutes, separate the organic phase, wash with 5% NaHCO3 until pH>7, separate the organic phase, vacuum rotary evaporation, add ethanol (80ml) for pulping, filter, and dry to obtain compound 1-1 (yield: 58.8%).

[0058] Mass spectrum: C30H16D2N4, theoretical value: 436.17, measured value: 436.15. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.32~7.36 (2H, m), 7.54~7.59 (2H, m), 7.79~7.88 (4H, m), 8.11~8.16 (2H, m), 8.37~8.42 (2H, m), 8.68~8.70 (4H, s).

[0059]

[0060] Synthesis of compound 1-2: In a 500ml three-necked flask, under nitrogen protection, add intermediate 1-1-1 (30mmol) and THF (260ml), and start stirring. In a single-necked flask, add methanesulfonic anhydride (0.113mol) and heavy water (0.45mol) to prepare acid water in a molar ratio of 1:4, slowly add the acid water to the reaction system, heat to 80°C, react for 12 hours, stop heating, cool to room temperature, add 350ml of water, stand for 30 minutes, separate the organic phase, wash with 5% NaHCO3 until pH>7, separate the organic phase, vacuum rotary evaporation, add ethanol (80ml) for pulping, filter, and dry to obtain compound 1-2 (yield: 57.3%).

[0061] Mass spectrum: C30H16D2N4, theoretical value: 436.17, measured value: 436.20. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.52~7.61 (4H, m), 7.86~7.91 (2H, m), 8.42~8.50 (4H, m), 8.68~8.71 (4H, s), 8.78~8.83 (2H, m).

[0062]

[0063] Synthesis of compound 1-3: In a 500ml three-necked flask, under nitrogen protection, add intermediate 1-1-1 (30mmol) and THF (260ml), and start stirring. In a single-necked flask, add trifluoromethanesulfonic anhydride (0.15mol) and heavy water (0.45mol) to prepare acid water in a molar ratio of 1:3, slowly add the acid water to the reaction system, heat to 80°C, react for 12 hours, stop heating, cool to room temperature, add 350ml of water, stand for 30 minutes, separate the organic phase, wash with 5% NaHCO3 until pH>7, separate the organic phase, vacuum rotary evaporation, add ethanol (80ml) for pulping, filter, and dry to obtain compound 1-3 (yield: 59.3%).

[0064] Mass spectrum: C30H14D4N4, theoretical value: 438.18, measured value: 438.22. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.31~7.43 (4H, m), 8.11~8.17 (2H, m), 8.36~8.42 (2H, m), 8.68~8.71 (4H, s), 8.77~8.83 (2H, m).

[0065]

[0066] Synthesis of compound 1-4: In a 500ml three-necked flask, under nitrogen protection, add compound 1-1 (20mmol) and THF (175ml), and start stirring. In a single-necked flask, add methanesulfonic anhydride (0.075mol) and heavy water (0.3mol) to prepare acid water in a molar ratio of 1:4, slowly add the acid water to the reaction system, heat to 80°C, react for 10 hours, stop heating, cool to room temperature, add 300ml of water, stand for 30 minutes, separate the organic phase, wash with 5% NaHCO3 until pH>7, separate the organic phase, vacuum rotary evaporate, add ethanol (80ml) for pulping, filter, and dry to obtain compound 1-4 (yield: 57.5%).

[0067] Mass spectrum: C30H14D4N4, theoretical value: 438.18, measured value: 438.20. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.54~7.59 (2H, m), 7.79~7.88 (4H, m), 8.11~8.16 (2H, m), 8.48~8.50 (2H, m), 8.68~8.71 (4H, s).

[0068]

[0069] Synthesis of compound 1-5: In a 500ml three-necked flask, under nitrogen protection, compound 1-3 (17mmol) and THF (150ml) were added and stirring began. In a single-necked flask, trifluoromethanesulfonic anhydride (0.087mol) and heavy water (0.26mol) were added to prepare acid water in a molar ratio of 1:3, and the acid water was slowly added to the reaction system, heated to 80°C, reacted for 10 hours, stopped heating, cooled to room temperature, added 250ml of water, stood for 30 minutes, separated the organic phase, washed with 5% NaHCO3 until pH>7, separated the organic phase, vacuum rotary evaporation, added ethanol (80ml) for pulping, filtered, and dried to obtain compound 1-5 (yield: 55.3%).

[0070] Mass spectrum: C30H12D6N4, theoretical value: 440.19, measured value: 440.15. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.31~7.37 (2H, m), 7.83~7.88 (2H, m), 8.11~8.17 (2H, m), 8.36~8.42 (2H, m), 8.68~8.71 (4H, s).

[0071]

[0072] Synthesis of compound 1-6: In a 500ml three-necked flask, under nitrogen protection, compound 1-5 (20mmol) and THF (180ml) were added and stirring began. In a single-necked flask, trifluoromethanesulfonic anhydride (0.1mol) and heavy water (0.3mol) were added to prepare acid water in a molar ratio of 1:3, and the acid water was slowly added to the reaction system, heated to 80°C, reacted for 12 hours, stopped heating, cooled to room temperature, added 300ml of water, stood for 30 minutes, separated the organic phase, washed with 5% NaHCO3 until pH>7, separated the organic phase, vacuum rotary evaporation, added ethanol (80ml) for pulping, filtered, and dried to obtain compound 1-6 (yield: 53.7%).

[0073] Mass spectrum: C30H10D8N4, theoretical value: 442.20, measured value: 442.19. 1H-NMR (400MHz, CDCl3) (ppm) δ = 7.83~7.88 (2H, m), 8.12~8.17 (2H, m), 8.48~8.50 (2H, m), 8.68~8.70 (4H, s).

[0074] When the compound of the present invention is used in the n-type charge generation layer, the structure of the organic electroluminescent device in device examples 1 to 8 and device comparative examples 1 to 3 is: ITO / HTL:NPD-9(weight ratio 95:5%,10nm) / HTL(60nm) / RH:RD(97:3,30nm) / ETL(30nm) / n-CGL:Yb(99:1,10nm) / p-CGL:NPD-9(95:5,10nm) / HTL(60nm) / RH:RD(97:3,30nm) / ETL:Liq(50:50,30nm) / Liq(2nm) / Al(100nm).

[0075] The molecular structure of the material is as follows:

[0076] Device Example 1 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 an acetone:ethanol mixed solvent (volume ratio 1:1), baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0077] The glass substrate with the anode is placed in a vacuum chamber and evacuated to 1×10 -5Pa, vacuum evaporating a first hole injection layer on the above-mentioned anode layer film, using a multi-source co-evaporation method, adjusting the evaporation rate of the compound HTL to 0.1nm / s, the evaporation rate of the compound NPD-9 to 5% ratio, and the total evaporation film thickness to 10nm; then evaporating the compound HTL as the first hole transport layer, the evaporation rate is 0.1nm / s, and the thickness is 60nm; evaporating the first light-emitting layer on the above-mentioned hole transport layer, the light-emitting layer includes a red light host material and a red light guest material, using a multi-source co-evaporation method The method was used to adjust the evaporation rate of the red light host material (RH) to 0.1nm / s, the evaporation rate of the red light guest material (RD) to 3%, and the total evaporation film thickness to 30nm; ETL was vacuum evaporated on the light-emitting layer as the first electron transport layer, the evaporation rate was 0.1nm / s, and the total evaporation film thickness was 30nm; an n-type charge generation layer was vacuum evaporated on the electron transport layer, and the multi-source co-evaporation method was used to adjust the evaporation rate of compound 1-1 to 0.1nm / s, and the Yb evaporation rate was 1%. The ratio is set, and the total film thickness of the evaporation is 10nm; on this, a p-type charge generation layer is vacuum evaporated, and the evaporation rate of compound 2-3 is adjusted to 0.1nm / s by a multi-source co-evaporation method, and the evaporation rate of compound NPD-9 is set to 5%, and the total film thickness of the evaporation is 10nm; then, the compound HTL is evaporated as the second hole transport layer, and the evaporation rate is 0.1nm / s, and the thickness is 60nm; the second light-emitting layer is evaporated on the above hole transport layer, and the light-emitting layer includes a red light host material and a red light guest material. The red light host material (RH) was deposited at a rate of 0.1 nm / s, the red light guest material (RD) was deposited at a rate of 3%, and the total film thickness was 30 nm. ETL was vacuum-deposited on the light-emitting layer as the second electron transport layer at a rate of 0.1 nm / s, the Liq deposition rate was set at 50%, and the total film thickness was 30 nm. Liq with a thickness of 2 nm was vacuum-deposited on the electron transport layer as an electron injection layer, and an Al layer with a thickness of 100 nm was used as the cathode of the device.

[0078] Device Example 2 to Device Example 8 Organic light-emitting devices of Device Example 2 to Device Example 8 were prepared by a method similar to that of Device Example 1, except that Compound 1-1 and Compound 2-3 in Device Example 1 were replaced with corresponding compounds in Table 1 of the same mass.

[0079] Device Comparative Example 1~Device Comparative Example 2 Organic electroluminescent devices of device comparative examples 1 to 2 were prepared by a method similar to that of device example 1, except that compound 1-1 in device example 1 was replaced by Ref1 and Ref2 of the same mass.

[0080]

[0081] Test Case At a current density of 10 mA / cm 2 The driving voltage and current efficiency of the organic electroluminescent devices prepared in Device Examples 1 to 8 and Device Comparative Examples 1 to 2 were measured at a current density of 50 mA / cm 2 The service life of the organic electroluminescent device T95 prepared in Device Example 1 to Device Example 8 and Device Comparative Example 1 to Device Comparative Example 2 was measured. The results are shown in Table 1.

[0082]

[0083] It can be seen from the above results that when the organic compound of the present invention is used as the n-type charge generation layer of the organic electroluminescent device, it has a significantly lower driving voltage and a higher luminous efficiency compared with the comparative example.

[0084] In addition, it can be seen from the results of Comparative Example 2 that the difference between the structure of Comparative Example 2 and the structure of the present invention is that the structure in Comparative Example 2 is all deuterated. Since deuterium atoms can enhance the transition ability of electrons, the transition ability of the structure of Comparative Example 2 is too strong, which will accelerate the diffusion of n-type dopants such as alkali metals or alkaline earth metals to the p-CGL layer under the action of an external electric field, thereby causing the driving voltage of the device to increase during operation, significantly reducing the device life, and seriously affecting the efficiency and stability of the device.

[0085] 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. A nitrogen heterocyclic organic compound, characterized in that The compound has a structure shown in formula (I): ， Wherein, in formula (I), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 Any 1 to 4 of them are deuterium, and the remaining groups are hydrogen.

2. The nitrogen heterocyclic organic compound according to claim 1, characterized in that In formula (I), R 11 and / or R 17 is deuterium, and the remaining groups are hydrogen; Preferably, the structure represented by formula (I) is selected from any one of the following:

3. The nitrogen heterocyclic organic compound according to claim 1, characterized in that In formula (I), R 14 and / or R 15 is deuterium, and the remaining groups are hydrogen; Preferably, the structure represented by formula (I) is the following structure:

4. The nitrogen heterocyclic organic compound according to claim 1, characterized in that In formula (I), R 11 and / or R 17 is deuterium, R 14 and R 15 is deuterium, and the remaining groups are hydrogen; Preferably, the structure represented by formula (I) is selected from any one of the following:

5. The nitrogen heterocyclic organic compound according to claim 1, characterized in that The structure represented by formula (I) is selected from any one of the following:

6. Use of the nitrogen heterocyclic organic compound according to any one of claims 1 to 5 in an organic electroluminescent device and / or a perovskite solar cell; Preferably, the charge generation layer and / or electron transport layer of the organic electroluminescent device contains the nitrogen heterocyclic organic compound; Preferably, the organic electroluminescent device is a stacked organic electroluminescent device.

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode; a second electrode arranged opposite to the first electrode; and at least two light-emitting units arranged between the first electrode and the second electrode, wherein the charge generation layer between any two adjacent light-emitting units comprises at least one of the nitrogen heterocyclic organic compounds described in any one of claims 1 to 5.

8. The organic electroluminescent device according to claim 7, characterized in that: Each of the light-emitting units contains a light-emitting layer, a hole transport layer and an electron transport layer; Preferably, each of the light-emitting units further comprises a hole injection layer, an electron blocking layer, a hole blocking layer and an electron injection layer.

9. The organic electroluminescent device according to claim 8, characterized in that: The charge generation layer contains an n-type doping body and a p-type doping body, and the n-type doping body contains at least one of the nitrogen heterocyclic organic compounds.

10. The organic electroluminescent device according to claim 9, characterized in that: The p-type doping body contains at least one of the following compounds:

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