A N-containing organic compound and its electroluminescence application

Abstract

The present invention provides a nitrogen-containing organic compound and its electroluminescent application. The nitrogen-containing organic compound has the structure shown in Formula I. It can be used as a thermally activated delayed fluorescence material in organic optoelectronic devices, significantly improving the efficiency and lifespan of OLED devices and reducing driving voltage. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, in particular to an organic compound containing nitrogen and an electroluminescent application thereof. Background Art

[0002] According to the luminescence mechanism, there are four main types of materials that can be used for OLED light-emitting layers:

[0003] Fluorescent materials, phosphorescent materials, triplet-triplet annihilation (TTA) materials, and thermally activated delayed fluorescence (TADF) materials.

[0004] Among them, the theoretical maximum internal quantum yield of fluorescent materials and TTA materials is low, and the cost of phosphorescent materials is high. Currently, TADF materials are more widely used. The luminescence mechanism of TADF materials is that when the energy level difference between the singlet excited state and the triplet excited state is small, reverse intersystem crossing (RISC) occurs inside the molecule, and the T1 state excitons are upconverted to the S1 state by absorbing environmental heat. 75% of triplet excitons and 25% of singlet excitons can be utilized at the same time, and the theoretical maximum internal quantum yield can reach 100%. TADF materials are mainly organic compounds, do not require rare metal elements, have low production costs, and can be chemically modified by a variety of methods. However, there are relatively few TADF materials that have been discovered so far. It is necessary to develop low-cost TADF materials with high theoretical maximum internal quantum yields to further improve the overall performance of OLED display devices. Therefore, new TADF materials that can be used in OLED devices are urgently needed to be developed. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a N-containing organic compound and its electroluminescent application, which can effectively improve the efficiency and life of OLED devices and reduce the driving voltage.

[0006] The present invention provides a N-containing organic compound having the structure shown in Formula I:

[0007]

[0008] Wherein, L1 and L2 are independently selected from a single bond, a substituted or unsubstituted aryl or heteroaryl group;

[0009] X and Y are independently selected from substituted or unsubstituted aryl or heteroaryl or arylamine groups.

[0010] The present invention provides an organic light-emitting device, which includes an anode, a cathode, and an organic thin film layer located between the anode and the cathode. The organic thin film layer includes a light-emitting layer, and the light-emitting layer contains at least one of the above-mentioned N-containing organic compounds.

[0011] The present invention provides a display panel comprising the above-mentioned organic light-emitting device.

[0012] Compared with the prior art, the N-containing organic compound provided by the present invention can be used as a thermally activated delayed fluorescence material in organic optoelectronic devices, which can significantly improve the efficiency and lifespan of OLED devices and reduce the driving voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic structural diagram of the organic light-emitting device prepared in the present invention. DETAILED DESCRIPTION

[0014] The present invention provides a N-containing organic compound having the structure shown in Formula I:

[0015]

[0016] Wherein, L1 and L2 are independently selected from a single bond, a substituted or unsubstituted aryl or heteroaryl group;

[0017] X and Y are independently selected from substituted or unsubstituted aryl or heteroaryl or arylamine groups.

[0018] Optionally, the above L1 and L2 are independently selected from a single bond, a substituted or unsubstituted monocyclic aromatic group or a condensed aromatic group.

[0019] Optionally, the above L1 and L2 are independently selected from a single bond, a substituted or unsubstituted monocyclic aromatic group, or a condensed aromatic group formed by condensing 2 to 3 monocyclic aromatic groups.

[0020] Optionally, the above L1 and L2 are independently selected from a single bond, a substituted or unsubstituted phenylene or naphthylene.

[0021] When L1 and L2 are independently selected from a single bond, it means that X and Y are directly connected to the N atom respectively.

[0022] Optionally, the above X and Y are independently selected from a substituted or unsubstituted monocyclic aromatic group, a substituted or unsubstituted monocyclic heteroaromatic group, a substituted or unsubstituted fused aromatic group formed by condensing 2 to 4 monocyclic aromatic groups, a substituted or unsubstituted fused heteroaromatic group formed by condensing 2 to 6 monocyclic aromatic groups and monocyclic heteroaromatic groups, or an aromatic amine group.

[0023] Optionally, the above-mentioned monocyclic aromatic group is selected from phenyl.

[0024] Optionally, the above-mentioned monocyclic heteroaryl group is selected from a five-membered or six-membered monocyclic heteroaryl group containing any one or more of N, O, S, and Si.

[0025] Optionally, the monocyclic heteroaryl group is selected from furyl, thienyl, pyrrolyl, pyridyl, pyranyl, pyrimidinyl, pyrazinyl, triazinyl or silanyl, pyrazolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl, isothiazolyl.

[0026] Optionally, the condensed ring aromatic group formed by condensing 2 to 4 monocyclic aromatic groups is selected from naphthyl, anthracenyl, phenanthrenyl, pyrenyl, peryl, phenalenyl or phenalenyl.

[0027] Optionally, the condensed-ring heteroaryl group formed by condensing 2 to 6 monocyclic aromatic groups and monocyclic heteroaryl groups is selected from benzimidazolyl, benzoxazolyl, benzothiazolyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, dibenzosilanyl, fluorenyl, spirofluorenyl, spirosilanyl, benzonaphthopyrrolyl, benzonaphthofuranyl, benzonaphthothiophenyl or benzonaphthosilanyl.

[0028] The benzimidazolyl, carbazolyl, and benzonaphthopyrrolyl groups can be connected to the parent nucleus via a carbon atom in the structure, or can be connected to the parent nucleus via a nitrogen atom.

[0029] Optionally, X and Y are independently selected from any of the following structures:

[0030]

[0031]

[0032] R, P, Q, and Z are independently selected from NR1, O, S, SiR2R3, and CR4R5;

[0033] M is selected from S, O, NR6 or CR7R8;

[0034] R1-R8 are independently selected from H, deuterium, C1-C10 alkyl, aryl or heteroaryl;

[0035] R9, R 10 are independently selected from aryl or heteroaryl;

[0036] Any one or more hydrogen atoms in the above structures may be substituted with a substituent.

[0037] Optionally, R1 to R8 are independently selected from H, deuterium, C1 to C5 alkyl, monocyclic aryl or monocyclic heteroaryl.

[0038] Optionally, R1 to R8 are independently selected from H, deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, and pyridyl.

[0039] Optional, R9, R 10 are independently selected from phenyl or pyridinyl.

[0040] The above “any one or more hydrogen atoms in the above structure may be substituted by a substituent” includes R1 to R 10 Any one or more hydrogen atoms in .

[0041] Optionally, the substituent is selected from deuterium, halogen, C1-C10 alkyl, C1-C10 haloalkyl, C1-C10 deuterated alkyl, aryl or heteroaryl.

[0042] The selection of the above substituents is the same as that of the substituents of X and Y.

[0043] Optionally, X and Y may be further substituted by one or more of deuterium, halogen, C1-C10 alkyl, C1-C10 halogenated alkyl, C1-C10 deuterated alkyl, aryl or heteroaryl.

[0044] Optionally, X and Y may be further substituted by one or more of deuterium, halogen, C1-C5 alkyl, C1-C5 haloalkyl, C1-C5 deuterated alkyl, phenyl, biphenyl, naphthyl, pyridyl, furyl, thienyl, pyrrolyl, pyrimidinyl, pyrazinyl, and triazinyl.

[0045] Optionally, X and Y may be further substituted by one or more of deuterium, halogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, deuterated methyl (CD3), phenyl, biphenyl, and pyridyl.

[0046] Optionally, the N-containing organic compound has any of the following structures:

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] The N-containing organic compound having a structure as shown in Formula I provided by the present invention is illustratively prepared by the following synthetic route:

[0062]

[0063] The present invention uses a benzene unit as a linker to connect the electron-donating group D and the electron-accepting group A, which can reduce the spatial separation of the HOMO and LUMO of the molecule, achieve a higher oscillator strength, and thus achieve a high PLQY. In addition, the benzene group has excellent optical and electrical properties. The compound according to the present invention reduces the overlap of the HOMO and LUMO by introducing an electron-donating unit D and an electron-accepting unit A as well as a building block with greater steric hindrance. Since ΔEst is positively correlated with the overlap of the HOMO and LUMO, the energy level difference ΔEst between the S1 state and the T1 state of the compound according to the present invention is small. Under certain temperature conditions, the T1 state exciton can realize the process of T1→S1 by reverse intersystem crossing (RISC), and then radiatively decay from the S1 state to the ground state S0, which can be used as a thermally activated delayed fluorescence (TADF) material.

[0064] In organic electroluminescent devices, thermally activated delayed fluorescence (TADF) materials as dopant materials can achieve the joint participation of S1 and T1 excitons in fluorescence emission without introducing precious metals or rare earth metals. The theoretical IQE value can reach 100%, which is comparable to phosphorescent OLEDs. TADF materials are pure organic materials and have greater advantages in synthesis costs than phosphorescent OLEDs. TADF materials are composed of pure organic compounds and have better thermal stability, chemical stability and device operating stability. TADF materials are organic compounds with more chemical modifiability and can be used to synthesize a variety of target molecules according to needs.

[0065] In organic electroluminescent devices, achieving balanced carrier transport and mitigating efficiency roll-off requires a host material with excellent bipolar transport properties. TADF materials, due to their excellent bipolar transport properties, are well-suited as host materials for phosphorescent or fluorescent materials.

[0066] Based on this, the N-containing organic compound provided by the present invention has the property of thermally activated delayed fluorescence (TADF) and can be applied to light-emitting layer materials, specifically to light-emitting materials, host materials or guest materials of the light-emitting layer of organic electroluminescent devices.

[0067] The present invention provides an organic light-emitting device, which includes an anode, a cathode, and an organic thin film layer located between the anode and the cathode. The organic thin film layer includes a light-emitting layer, and the light-emitting layer contains at least one of the above-mentioned N-containing organic compounds.

[0068] The present invention provides a display panel comprising the above-mentioned organic light-emitting device.

[0069] The organic light-emitting device provided by the present invention can be an organic light-emitting device familiar to those skilled in the art. Optionally, the organic light-emitting device includes a substrate, an ITO anode, a first hole transport layer, a second hole transport layer, an electron blocking layer, a light-emitting layer, a first electron transport layer, a second electron transport layer, a cathode (magnesium-silver electrode, magnesium-silver mass ratio of 1:9) and a capping layer (CPL).

[0070] Optionally, the anode material of the organic light-emitting device can be selected from metals such as copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, and alloys thereof; such as metal oxides such as indium oxide, zinc oxide, indium tin oxide (ITO), indium zinc oxide (IZO), and the like; such as conductive polymers such as polyaniline, polypyrrole, and poly (3-methylthiophene), and in addition to the above materials that facilitate hole injection and their combinations, also include known materials suitable for anodes.

[0071] Optionally, the cathode material of the organic light-emitting device can be selected from metals such as aluminum, magnesium, silver, indium, tin, titanium, and alloys thereof; such as multilayer metal materials such as LiF / Al, LiO2 / Al, BaF2 / Al, etc.; in addition to the above materials and combinations thereof that facilitate electron injection, also known materials suitable for cathodes are included.

[0072] Optionally, the organic photoelectric device, such as the organic thin film layer in the organic light-emitting device, has at least one light-emitting layer (EML) and may further include other functional layers, including a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0073] Optionally, the organic light-emitting device is prepared according to the following method:

[0074] An anode is formed on a transparent or opaque smooth substrate, an organic thin layer is formed on the anode, and a cathode is formed on the organic thin layer.

[0075] Optionally, in the present invention, the organic thin layer may be formed by using known film forming methods such as evaporation, sputtering, spin coating, dipping, ion plating, etc.

[0076] The present invention provides a display device including the above-mentioned display panel.

[0077] In the present invention, an organic light-emitting device (OLED device) can be used in a display device, wherein the organic light-emitting display device can be a mobile phone display, a computer display, a TV display, a smart watch display, a smart car display panel, a VR or AR helmet display, a display of various smart devices, etc.

[0078] The following will be a clear and complete description of the technical solutions of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0079] Example 1

[0080]

[0081] By 9.5mmol of reactant A, 11.4mmol of reactant B1, 0.5mmol of Pd(PPh ) 4 and 19mmol of K CO Join in the pure water of 30mL of toluene, 7mL of EtOH and 10mL, and mixture was stirred 4 hours under reflux.After reaction is completed, reaction mixture is cooled to room temperature and at room temperature stirs, then MeOH is added wherein.The solid of gained is filtered under reduced pressure, then separated by column chromatography with MC, to obtain compound T1.

[0082] MALDI-TOF: m / z: calculated: C 42 H 27 N3O: 589.22, measured value: 589.56.

[0083] Elemental analysis results of the compound: Calculated value: C 42 H 27 N3O (%): C, 85.55; H, 4.62; N, 7.13; O, 2.71; Test value: C, 85.54; H, 4.63; N, 7.13; O, 2.70.

[0084] Example 2

[0085]

[0086] By 9.5mmol of reactant A, 11.4mmol of reactant B9, 0.5mmol of Pd(PPh ) 4 and 19mmol of K CO Join in the pure water of 30mL of toluene, 7mL of EtOH and 10mL, and mixture was stirred 4 hours under reflux.After reaction is completed, reaction mixture is cooled to room temperature and at room temperature stirs, then MeOH is added wherein.The solid of gained is filtered under reduced pressure, then separated by column chromatography with MC, to obtain compound T9.

[0087] MALDI-TOF: m / z: calculated: C 41 H 31 N3: 565.25, measured value: 565.48.

[0088] Elemental analysis results of the compound: Calculated value: C 41 H 31 N3(%): C, 87.05; H, 5.52; N, 7.43; Test value: C, 87.06; H, 5.51; N, 7.43.

[0089] Example 3

[0090]

[0091] By 9.5mmol of reactant A, 11.4mmol of reactant B16, 0.5mmol of Pd(PPh ) 4 and 19mmol of K CO Join in the pure water of 30mL of toluene, 7mL of EtOH and 10mL, and mixture was stirred 4 hours under reflux.After reaction is completed, reaction mixture is cooled to room temperature and at room temperature stirs, then MeOH is added wherein.The solid of gained is filtered under reduced pressure, then separated by column chromatography with MC, to obtain compound T16.

[0092] MALDI-TOF: m / z: calculated: C 44 H 30 N4: 614.25, measured value: 614.49.

[0093] Elemental analysis results of the compound: Calculated value: C 44 H 30 N4 (%): C, 85.97; H, 4.92; N, 9.11; Test value: C, 85.96; H, 4.92; N, 9.12.

[0094] Example 4

[0095]

[0096] The synthesis method of compound T28 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B28.

[0097] MALDI-TOF: m / z: calculated: C 52 H 34 N4: 714.28, measured value: 714.63.

[0098] Elemental analysis results of the compound: Calculated value: C 52 H 34 N4 (%): C, 87.37; H, 4.79; N, 7.84; Test value: C, 87.37; H, 4.79; N, 7.84.

[0099] Example 5

[0100]

[0101] The synthesis method of compound T32 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B32.

[0102] MALDI-TOF: m / z: calculated: C 48 H 32 N4: 664.26, measured value: 664.74.

[0103] Elemental analysis results of the compound: Calculated value: C 48 H 32 N4 (%): C, 86.72; H, 4.85; N, 8.43; Test value: C, 86.72; H, 4.85; N, 8.43.

[0104] Example 6

[0105]

[0106] The synthesis method of compound T48 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B48.

[0107] MALDI-TOF: m / z: calculated: C 39 H 26 N4O: 566.21, measured value: 566.47.

[0108] Elemental analysis results of the compound: Calculated value: C 39 H 26 N4O (%): C, 82.66; H, 4.62; N, 9.89; O, 2.82; Test value: C, 82.67; H, 4.61; N, 9.88; O, 2.83.

[0109] Example 7

[0110]

[0111] The synthesis method of compound T55 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B55.

[0112] MALDI-TOF: m / z: calculated: C 42 H 29 N3: 575.24, measured value: 575.47.

[0113] Elemental analysis results of the compound: Calculated value: C 42 H 29 N3 (%): C, 87.62; H, 5.08; N, 7.30; Test value: C, 87.63; H, 5.07; N, 7.30.

[0114] Example 8

[0115]

[0116] The synthesis method of compound T72 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B72.

[0117] MALDI-TOF: m / z: calculated: C 52 H 37 N3Si: 731.28, measured value: 731.62.

[0118] Elemental analysis results of the compound: Calculated value: C 52 H 37 N3Si(%): C, 85.33; H, 5.10; N, 5.74; Si, 3.84; tested value: C, 85.32; H, 5.09; N, 5.75; Si, 3.84.

[0119] Example 9

[0120]

[0121] The synthesis method of compound T100 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B100.

[0122] MALDI-TOF: m / z: calculated: C 57 H 37 N3O: 779.29, measured value: 779.54.

[0123] Elemental analysis results of the compound: Calculated value: C57 H 37 N3O (%): C, 87.78; H, 4.78; N, 5.39; O, 2.05; Test value: C, 87.79; H, 4.77; N, 5.38; O, 2.05.

[0124] Example 10

[0125]

[0126] The synthesis method of compound T134 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B134.

[0127] MALDI-TOF: m / z: calculated: C 44 H 29 N3O: 615.23, measured value: 615.49.

[0128] Elemental analysis results of the compound: Calculated value: C 44 H 29 N3O (%): C, 85.83; H, 4.75; N, 6.82; O, 2.60; Test value: C, 85.84; H, 4.74; N, 6.82; O, 2.60.

[0129] Example 11

[0130]

[0131] The synthesis method of compound T139 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B139.

[0132] MALDI-TOF: m / z: calculated: C 53 H 37 N3O: 731.29, measured value: 731.53.

[0133] Elemental analysis results of the compound: Calculated value: C 53 H 37 N3O (%): C, 86.98; H, 5.10; N, 5.74; O, 2.19; Test value: C, 86.97; H, 5.11; N, 5.74; O, 2.18.

[0134] Example 12

[0135]

[0136] The synthesis method of compound T187 is similar to that of T1, except that B1 in the reaction is replaced by an equimolar amount of B187.

[0137] MALDI-TOF: m / z: calculated: C 50 H 31 D2N3O: 693.27, measured value: 693.61.

[0138] Elemental analysis results of the compound: Calculated value: C 50 H 31 D2N3O (%): C, 86.55; H, 5.08; N, 6.06; O, 2.31; Test value: C, 86.56; H, 5.07; N, 6.06; O, 2.30.

[0139] Device Example 1

[0140] This embodiment provides an organic light-emitting device, the device structure of which is:

[0141] ITO(10nm) / HAT-CN(10nm) / NPB(40nm) / TAPC(10nm) / CBP: T1(20nm) / TPBi(30nm) / LiF(2nm) / Al(100nm).

[0142] In the above device structure, ITO is used as the anode material; HAT-CN is used as the hole injection layer material, NPB and TAPC are used as the first and second hole transport layer materials, respectively; the light-emitting layer is composed of the guest material T1 doped into the host material CBP in a certain proportion; TPBi is used as the electron transport layer material; LiF is used as the electron injection layer material; and Al is used as the cathode material.

[0143] The specific preparation steps are as follows:

[0144] 1) A glass substrate 1 was cut into 50 mm × 50 mm × 0.7 mm pieces and cleaned by ultrasonic cleaning in acetone, isopropyl alcohol, and deionized water for 30 minutes, respectively, followed by UV ozone cleaning for 30 minutes. The glass substrate, on which a 10 nm thick indium tin oxide (ITO) anode 2 was deposited by magnetron sputtering, was mounted on a vacuum deposition apparatus.

[0145] 2) On the ITO anode layer 2, a hole injection layer material HAT-CN is deposited by vacuum evaporation as a hole injection layer 3 with a thickness of 10 nm;

[0146] 3) vacuum evaporating a hole transport layer material NPB on the hole injection layer 3 as the first hole transport layer 4 with a thickness of 40 nm;

[0147] 4) vacuum evaporating a hole transport material TAPC on the first hole transport layer 4 as the second hole transport layer 5 with a thickness of 10 nm;

[0148] 5) Vacuum-depositing a light-emitting layer 6 on the second hole transport layer 5 to a thickness of 20 nm; wherein CBP is used as the host material and the compound T1 of the present invention is used as the doping material (guest material) at a doping ratio of 3% (mass ratio);

[0149] 6) Vacuum-depositing an electron transport material TPBi on the light-emitting layer 6 as an electron transport layer 7 with a thickness of 30 nm;

[0150] 7) Vacuum evaporation of electron transport material LiF on the electron transport layer 7 as the electron injection layer 8 with a thickness of 2 nm;

[0151] 8) An aluminum (Al) electrode is vacuum-deposited on the electron transport layer 8 as a cathode 9 with a thickness of 100 nm.

[0152] The structures of the compounds used in the preparation of OLED devices are as follows:

[0153]

[0154] Device Examples 2 to 9

[0155] The organic compound T1 in step (5) of device example 1 was replaced by an equal amount of compound T9, T28, T32, T48, T55, T72, T100 or T134, respectively. The other preparation steps were the same as those of device example 1.

[0156] Device Comparative Examples 1-2

[0157] An OLED device differs from the device in Example 1 only in that the doping material in step (5) is replaced by equal amounts of comparative compounds Ir(MDQ)2(acac) and REF2; other raw materials and preparation steps are the same.

[0158] Performance evaluation of OLED devices:

[0159] The current of the OLED device at different voltages was measured using a Keithley 2365A digital nanovoltmeter, and the current was divided by the luminous area to obtain the current density of the OLED device at different voltages. The brightness and radiant energy flux density of the OLED device at different voltages were measured using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED device at different voltages, the current density (10 mA / cm 2 ) of the turn-on voltage and current efficiency (CE, Cd / A), VON is the brightness of 1Cd / m 2 The life span LT95 (at 50 mA / cm2) was obtained by measuring the time when the brightness of the OLED device reached 95% of the initial brightness. 2Specific data are shown in Table 1.

[0160] Table 1 OLED device performance test results

[0161]

[0162] As shown in Table 1, compared with the doping materials Ir(MDQ)2(acac) and REF2, the organic light-emitting devices prepared based on the doping materials of the present invention show excellent characteristics in terms of driving voltage, luminous efficiency and lifespan. In particular, good performance is shown in terms of efficiency. This is mainly due to the fact that the TADF material of the present invention can reduce the degree of spatial separation of the HOMO and LUMO of the molecule by using a benzene ring as a connecting unit of the electron-donating group D and the electron-accepting group A, thereby achieving a higher oscillator strength, and then achieving a high photoluminescence quantum yield (PLQY), and achieving a higher device efficiency. By selecting and optimizing the X and Y units (such as selecting spiro rings, ortho-linking groups, etc.), the compound has suitable spatial distortion, improving the triplet energy level of the material, promoting effective energy transfer from the host material to the guest material, reducing energy backtransmission, and improving the luminous efficiency of the device. In addition, the enhanced stereoscopic nature of the molecular structure can also reduce the molecular force and reduce intermolecular stacking, which is conducive to reducing concentration quenching.

[0163] Device Examples 10-12

[0164] Using compounds T16, T139, and T187 as the main materials and Ir(ppy)3 as the dopant, device embodiments 10 to 12 were designed with the following structures: ITO (10nm) / HAT-CN (10nm) / NPB (40nm) / TAPC (10nm) / Tx: Ir(ppy)3 (20nm) / TPBi (30nm) / LiF (2nm) / Al (100nm).

[0165] The CBP in step (5) of device embodiment 1 is replaced by an equal amount of compound T16, T139 or T87, the doping material T1 is replaced by an equal amount of compound Ir(ppy)3, and the doping ratio of the dopant is replaced from 3% to 6%. The other preparation steps are the same as those of device embodiment 1.

[0166] Device Comparative Examples 3-4

[0167] An OLED device differs from the device in Example 2 only in that the main material in step (5) is replaced by equal amounts of the comparative compounds CBP and REF2, the doping material is replaced by an equal amount of the compound Ir(ppy)3, and the doping ratio of the dopant is replaced from 3% to 6%; the other raw materials and preparation steps are the same.

[0168] The performance evaluation equipment and method of device embodiments 10-12 are the same as those of device embodiments 1-9, and the specific performance data are shown in Table 2.

[0169] Table 2 OLED device performance test results

[0170]

[0171] As can be seen from Table 2, devices using the compounds of the present invention as the main material and Ir(ppy)3 as the dopant material have a certain degree of improvement in driving voltage, luminous efficiency, and lifespan. This is because the materials of the present invention have the bipolar characteristic of simultaneously transmitting holes and electrons. Such compounds are beneficial to the charge transfer balance in the light-emitting layer, can expand the area where holes and electrons recombine into excitons, dilute the exciton concentration per unit volume, prevent triplet excitons from concentration annihilation or triplet-triplet exciton annihilation caused by high concentrations, and improve device efficiency. In addition, the series of TADF materials of the present invention have high thermal stability and morphological stability, excellent film-forming properties, and are not easy to crystallize as light-emitting layer materials, which is beneficial to improving the performance and luminous efficiency of OLED devices.

[0172] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A N-containing organic compound, characterized in that Has any of the following structures:

2. An organic light-emitting device, comprising an anode, a cathode, and an organic thin film layer located between the anode and the cathode, wherein the organic thin film layer comprises a light-emitting layer, and the light-emitting layer contains at least one N-containing organic compound according to claim 1.

3. A display panel comprising the organic light-emitting device according to claim 2.

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