Heterocyclic compounds containing heteroatom-substituted fluorenes and their use in optoelectronic devices

Abstract

The application provides a heterocyclic compound containing a heteroatom-substituted fluorene, which has a structure shown in formula I. The heterocyclic compound prepared by specific heteroatom substitution of a fluorene group has the following advantages: (1) high refractive index and high light extraction efficiency; (2) no absorption in the respective wavelength regions of blue, green and red, and no reduction in color purity; (3) small difference between the refractive indexes measured in the respective wavelength regions of blue, green and red; (4) high glass transition temperature, high decomposition temperature, material capable of being evaporated but not thermally decomposed; (5) high stability, excellent durability and long service life of the film formed by the material.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and more particularly to a heterocyclic compound containing heteroatoms-substituted fluorene and its application in optoelectronic devices. Background Technology

[0002] Based on the direction of light emission from the organic light-emitting layer, OLED displays can be divided into bottom-emitting OLED displays and top-emitting OLED displays. In bottom-emitting OLED displays, light is emitted towards the substrate, with reflective electrodes formed on the organic light-emitting layer and transparent electrodes formed below it. If the OLED display is an active-matrix OLED, the thin-film transistor portions do not transmit light, thus reducing the light-emitting area. On the other hand, in top-emitting OLED displays, the transparent electrodes are formed on the organic light-emitting layer, and the reflective electrodes are formed below it, so light is emitted in the opposite direction to the substrate, thereby increasing the light transmission area and improving brightness.

[0003] Currently, the refractive index of OLED devices does not meet market demand, resulting in insufficient light extraction efficiency. The difference in refractive index measured in the wavelength regions of blue, green, and red is significant, therefore, all light from each of the blue, green, and red light-emitting devices cannot simultaneously achieve high light extraction efficiency.

[0004] To address the current low light extraction efficiency of OLED devices, a CPL layer, or light extraction material, needs to be added to the device structure. Based on the principles of optical absorption and refraction, the refractive index of this surface coating material should be as high as possible. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a heterocyclic compound containing heteroatoms substituted for fluorene and its application in optoelectronic devices. The prepared heterocyclic compound has a high refractive index and light extraction efficiency.

[0006] This invention provides a heterocyclic compound containing heteroatom-substituted fluorene, having the structure shown in Formula I:

[0007]

[0008] Where Y is selected from O or S;

[0009] At least one of X1, X2, X3, X4, X5, X6, X7, and X8 is an N atom, and the rest are CR2.

[0010] L1, L2, and L3 are independently selected from single-bonded, substituted, or unsubstituted aromatic groups;

[0011] Ar1 and Ar2 are independently selected from substituted or unsubstituted aromatic or heteroaryl groups;

[0012] R1 is a hydrogen atom, a deuterium atom, or an aromatic or heteroaryl group fused with an adjacent group;

[0013] R2 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted C1-C5 alkyl group, a halogen, a cyano group, or an amino group.

[0014] The present invention provides a display panel including an organic light-emitting device, the organic light-emitting device including an anode, a cathode and an organic thin layer located between the anode and the cathode, and a capping layer covering the cathode, the capping layer including any one or at least two combinations of the above-mentioned heterocyclic compounds.

[0015] The present invention provides a display device, including the above-described display panel.

[0016] Compared with existing technologies, this invention provides a heterocyclic compound containing heteroatom-substituted fluorene, having the structure shown in Formula I. The heterocyclic compound prepared by this invention through specific heteroatom substitution of the fluorene group has the following advantages:

[0017] (1) High refractive index, high light extraction efficiency; (2) No absorption in the wavelength regions of blue, green and red, and the color purity will not decrease; (3) The difference in refractive index measured in the wavelength regions of blue, green and red is small; (4) High glass transition temperature, high decomposition temperature, the material can be vapor-deposited but will not thermally decompose; (5) The film formed by the material has high stability, excellent durability and long life.

[0018] Experimental results show that when the above-mentioned specific type of heterocyclic compound is used to prepare the capping layer and the capping layer is used to prepare the organic electroluminescent device, the current efficiency, light extraction efficiency and color shift at a large viewing angle of the organic electroluminescent device prepared by the capping layer prepared by the specific type of heterocyclic compound are improved because the refractive index of the heterocyclic compound in the visible light region is high and the extinction coefficient is very low. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the organic light-emitting device provided by the present invention. Detailed Implementation

[0020] This invention provides a heterocyclic compound containing heteroatom-substituted fluorene, having the structure shown in Formula I:

[0021]

[0022] Where Y is selected from O or S;

[0023] At least one of X1, X2, X3, X4, X5, X6, X7, and X8 is an N atom, and the rest are CR2.

[0024] L1, L2, and L3 are independently selected from single-bonded, substituted, or unsubstituted aromatic groups;

[0025] Ar1 and Ar2 are independently selected from substituted or unsubstituted aromatic or heteroaryl groups;

[0026] R1 is a hydrogen atom, a deuterium atom, or an aromatic or heteroaryl group fused with an adjacent group;

[0027] R2 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted C1-C5 alkyl group, a halogen, a cyano group, or an amino group.

[0028] This invention provides a heterocyclic compound containing heteroatom-substituted fluorene and its application in optoelectronic devices. The prepared heterocyclic compound exhibits high refractive index across the entire visible light region, with small differences in refractive index measured in the blue, green, and red wavelength regions. It demonstrates high light extraction efficiency in blue, green, and red light-emitting devices, achieving higher device efficiency. By introducing heteroatom-substituted fluorene into the molecular structure, this invention significantly enhances the molecular polarizability despite a small change in molecular volume, achieving a comprehensive improvement in refractive index across the blue, green, and red light regions.

[0029] Optionally, the substituents of the aromatic or heteroaryl group are selected from C1-C10 alkyl groups and C1-C10 alkoxy groups.

[0030] Optionally, any one, two, or three of X1, X2, X3, X4, X5, X6, X7, and X8 may be N atoms, and the rest may be CR2.

[0031] Optionally, R2 is a hydrogen atom, a deuterium atom, F, Cl, Br, a cyano group, or a trifluoromethyl group.

[0032] Optionally, the heteroatom-substituted fluorene in Formula I has any of the following structures:

[0033]

[0034] Y is either O or S;

[0035] The above structure is connected to L1 via any carbon atom.

[0036] Optionally, the heteroatom-substituted fluorene in Formula I has any of the following structures:

[0037]

[0038]

[0039] Y is either O or S;

[0040] The above structure is connected to L1 via any carbon atom.

[0041] Optionally, the heteroatom-substituted fluorene in Formula I has any of the following structures:

[0042]

[0043] Y is either O or S;

[0044] The above structure is connected to L1 via any carbon atom.

[0045] Optionally, the heteroatom-substituted fluorene in Formula I has any of the following structures:

[0046]

[0047] Y is either O or S;

[0048] The above structure is connected to L1 via any carbon atom.

[0049] The heteroatom-substituted fluorene finger structure above refers to the following structures:

[0050]

[0051] Optionally, the heterocyclic compound has any of the following structures:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063] Optionally, L1, L2, and L3 are independently selected from single-bonded, substituted, or unsubstituted aromatic groups. The substituents of the aromatic group may be selected from deuterium atoms.

[0064] Optionally, L1, L2, and L3 are independently selected from phenylene, biphenylene, terphenylene, naphthylene, anthracene, phenanthrene, pyrene, fluorene, terphenylene, or fluorene.

[0065] Optionally, L1, L2, and L3 are independently selected from any of the following structures:

[0066]

[0067]

[0068]

[0069] # indicates the connection position.

[0070] Optionally, Ar1 and Ar2 are independently selected from substituted or unsubstituted aromatic or heteroaryl groups. The substituents of the aforementioned aromatic or heteroaryl groups may be selected from deuterium atoms.

[0071] Optionally, Ar1 and Ar2 are independently selected from substituted or unsubstituted fused-ring aromatic groups or fused-ring heteroaryl groups. The substituents of the aforementioned fused-ring aromatic groups or fused-ring heteroaryl groups may be selected from deuterium atoms.

[0072] Optionally, Ar1 and Ar2 are independently selected from phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, pyrene, fluoranyl, triphenylene, fluorenyl, pyrrolyl, furanyl, thiophene, pyridyl, pyrimidinyl, pyridazinyl, triazinyl, benzofuranyl, benzothiophene, dibenzofuranyl, dibenzothiophene, oxazolyl, oxadiazolyl, thiazolyl, thiazolyl, benzoxazolyl, benzothiazolyl, imidazolyl, pyrazolyl, indolyl, quinolinyl, isoquinolinyl, purine, isoxazolyl, isothiazolyl, pyranone, pyrazinyl, thienofuranyl, thienopyrrolyl, pyrrolopyridyl, pyridinolpyrimidinyl, pyrazoloxazolyl, pyrazinolpyridazinyl, imidazothiazolyl, or coumarinyl.

[0073] Optionally, Ar1 and Ar2 are independently selected from any of the following structures:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] # indicates the connection position.

[0085] Optionally, the heterocyclic compound has any of the following structures:

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112] The preparation method of the above-mentioned heterocyclic compounds provided by the present invention belongs to the prior art. Those skilled in the art can select specific synthesis methods based on conventional technical knowledge. The present invention only provides exemplary synthesis paths, but is not limited to the following synthesis paths.

[0113] The representative synthetic route of the compound of formula I provided by this invention is as follows:

[0114]

[0115] The compounds provided by this invention can be applied to the CPL layer of top-emitting OLED devices; they can also be used as optical auxiliary layers such as hole transport layers and electron blocking layers.

[0116] The present invention provides a display panel including an organic light-emitting device, the organic light-emitting device including an anode, a cathode and an organic thin layer located between the anode and the cathode, and a capping layer covering the cathode, the capping layer including any one or at least two combinations of the above-mentioned heterocyclic compounds.

[0117] The present invention provides a display panel including an organic light-emitting device, the organic light-emitting device including an anode, a cathode and an organic thin layer located between the anode and the cathode, the organic thin layer including a hole transport layer, the hole transport layer including any one or at least two combinations of the above-mentioned heterocyclic compounds.

[0118] The present invention provides a display panel including an organic light-emitting device, the organic light-emitting device including an anode, a cathode and an organic thin layer located between the anode and the cathode, the organic thin layer including an electron blocking layer, the electron blocking layer including any one or at least two combinations of the above-mentioned heterocyclic compounds.

[0119] The organic light-emitting device provided by the present invention 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 with a magnesium-silver mass ratio of 1:9) and a capping layer (CPL) stacked sequentially.

[0120] 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 their alloys; metal oxides such as indium oxide, zinc oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); and conductive polymers such as polyaniline, polypyrrole, and poly(3-methylthiophene). In addition to the above-mentioned hole-injection materials and combinations thereof, it also includes known materials suitable for anodes.

[0121] Optionally, the cathode material of the organic light-emitting device may be selected from metals such as aluminum, magnesium, silver, indium, tin, titanium, and their alloys; such as multilayer metal materials such as LiF / Al, LiO2 / Al, BaF2 / Al, etc.; in addition to the above materials and combinations that facilitate electron injection, it also includes known materials suitable for use as cathodes.

[0122] Optionally, the organic optoelectronic device, such as an organic light-emitting device, may have at least one light-emitting layer (EML) in its organic thin film layer, and may also 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).

[0123] Optionally, the organic light-emitting device is prepared according to the following method:

[0124] An anode is formed on a smooth, transparent or opaque substrate, an organic thin layer is formed on the anode, and a cathode is formed on the organic thin layer.

[0125] Optionally, the organic thin layer can be formed using known film-forming methods such as vapor deposition, sputtering, spin coating, immersion, and ion plating.

[0126] The present invention provides a display device, including the above-described display panel.

[0127] In this invention, organic light-emitting devices (OLED devices) can be used in display devices, which can be mobile phone displays, computer displays, television displays, smartwatch displays, smart car display panels, VR or AR helmet displays, displays of various smart devices, etc.

[0128] The technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0129] Example 1

[0130] The synthetic route for compound M001 is as follows:

[0131]

[0132] The specific preparation method includes the following steps:

[0133]

[0134] (1) Add MO001-1 (0.5 mmol), MO001-2 (0.75 mmol), K2CO3 (0.5 mmol), and PdCl2 (5 × 10⁻⁶ mmol) to the solution. - 4 mmol), TPDA (5×10 -4 mmol) was added to 3 mL of o-xylene solution and mixed, then placed in a 50 mL flask and reacted at 100 °C for 24 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then solvent-removed by rotary evaporation, and the crude product M001-3 was obtained by column chromatography.

[0135] (2) M001-3 (0.5 mmol), M001-4 (1.5 mmol), KO(t-Bu) (0.75 mmol), [Pd(cinnamyl)Cl]2 (2 mol%), and Ligand (1.5 mol%) were added to 3 mL of toluene solution and mixed. The mixture was placed in a 50 mL flask and reacted at 110 °C for 12 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then purified by rotary evaporation to remove the solvent, and the crude product M001 was obtained by column chromatography.

[0136] The structure of the target product M001 was determined by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS, m / z): C 47 H 30 N4O, calculated value is 666.2, tested value is 666.1.

[0137] Elemental analysis: Theoretical values: C, 84.66; H, 4.54; N, 8.40; Measured values: C, 84.66; H, 4.53; N, 8.40.

[0138] Example 2

[0139] The synthetic route for compound M029 is as follows:

[0140]

[0141] The specific preparation method includes the following steps:

[0142]

[0143] (1) M001-3 (0.5 mmol), M029-1 (1.5 mmol), KO(t-Bu) (0.75 mmol), [Pd(cinnamyl)Cl]2 (2 mol%), and Ligand (1.5 mol%) were added to 3 mL of toluene solution and mixed. The mixture was placed in a 50 mL flask and reacted at 110 °C for 12 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then purified by rotary evaporation to remove the solvent, and the crude product M029 was obtained by column chromatography.

[0144] The structure of the target product M029 was determined by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS, m / z): C 43 H 26 N4O3, calculated value 646.2, tested value 646.3.

[0145] Elemental analysis: Theoretical values: C, 79.86; H, 4.05; N, 8.66; Measured values: C, 79.87; H, 4.05; N, 8.66.

[0146] Example 3

[0147] The synthetic route for compound M039 is as follows:

[0148]

[0149] The specific preparation method includes the following steps:

[0150]

[0151] (1) M001-3 (0.5 mmol), M039-1 (1.5 mmol), KO(t-Bu) (0.75 mmol), [Pd(cinnamyl)Cl]2 (2 mol%), and Ligand (1.5 mol%) were added to 3 mL of toluene solution and mixed. The mixture was placed in a 50 mL flask and reacted at 110 °C for 12 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then purified by rotary evaporation to remove the solvent, and the crude product M039 was obtained by column chromatography.

[0152] The structure of the target product M039 was determined by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS, m / z): C 49 H 32 The calculated value of N2O is 664.2, and the measured value is 664.3.

[0153] Elemental analysis: Theoretical values: C, 88.53; H, 4.85; N, 4.21; Measured values: C, 88.53; H, 4.86; N, 4.21.

[0154] Example 4

[0155] The synthetic route for compound M265 is as follows:

[0156]

[0157] The specific preparation method includes the following steps:

[0158]

[0159] (1) Add M265-1 (0.5 mmol), M001-2 (0.75 mmol), K2CO3 (0.5 mmol), and PdCl2 (5 × 10⁻⁶ mmol) to the solution. - 4 mmol), TPDA (5×10 -4 mmol) was added to 3 mL of o-xylene solution and mixed, then placed in a 50 mL flask and reacted at 100 °C for 24 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then solvent-removed by rotary evaporation, and the crude product M265-2 was obtained by column chromatography.

[0160] (2) M265-2 (0.5 mmol), MO29-1 (1.5 mmol), KO(t-Bu) (0.75 mmol), [Pd(cinnamyl)Cl]2 (2 mol%), and Ligand (1.5 mol%) were added to 3 mL of toluene solution and mixed. The mixture was placed in a 50 mL flask and reacted at 110 °C for 12 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then purified by rotary evaporation to remove the solvent, and the crude product M265 was obtained by column chromatography.

[0161] The structure of the target product M265 was tested: MALDI-TOF MS (m / z) was obtained by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry analysis: C 42 H 25 N5O2S, calculated value is 663.2, tested value is 663.1.

[0162] Elemental analysis: Theoretical values: C, 76.00; H, 3.80; N, 10.55; Measured values: C, 76.01; H, 3.80; N, 10.55.

[0163] Example 5

[0164] The synthetic route for compound M382 is as follows:

[0165]

[0166] The specific preparation method includes the following steps:

[0167]

[0168] (1) Add M001-1 (0.5 mmol), M382-1 (0.75 mmol), K2CO3 (0.5 mmol), and PdCl2 (5 × 10⁻⁶ mmol) to the solution. - 4 mmol), TPDA (5×10 -4 mmol) was added to 3 mL of o-xylene solution and mixed, then placed in a 50 mL flask and reacted at 100 °C for 24 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then solvent-removed by rotary evaporation, and the crude product M382-2 was obtained by column chromatography.

[0169] (2) M382-2 (0.5 mmol), M382-3 (1.5 mmol), KO(t-Bu) (0.75 mmol), [Pd(cinnamyl)Cl]2 (2 mol%), and Ligand (1.5 mol%) were added to 3 mL of toluene solution and mixed. The mixture was placed in a 50 mL flask and reacted at 110 °C for 12 hours. After cooling to room temperature, saturated MgSO4 aqueous solution and ethyl acetate were slowly added to the solution for extraction three times. The organic layer was then purified by rotary evaporation to remove the solvent, and the crude product M382 was obtained by column chromatography.

[0170] The structure of the target product M382 was tested: MALDI-TOF MS (m / z) was obtained by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry analysis: C 47 H 28 N4OS2, calculated value 728.2, test value 728.1.

[0171] Elemental analysis: Theoretical values: C, 77.45; H, 3.87; N, 7.69; Measured values: C, 77.44; H, 3.88; N, 7.69.

[0172] The preparation methods of the compounds of the present invention used in the specific embodiments are similar to those described above, and will not be repeated one by one. Only the characterization results are provided. The mass spectrometry analysis and elemental analysis results are shown in Table 1.

[0173] Table 1

[0174]

[0175]

[0176]

[0177] The refractive index of the compound was measured, and the results are shown in Table 2:

[0178] Table 2

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194]

[0195]

[0196] The data in Table 1 show that, compared with the commonly used capping layer material ref 1 in the industry, the compound of the present invention has a higher refractive index in the entire visible light wavelength range; based on this, it is inferred that using the above material as the capping layer material in blue, green and red light devices is expected to achieve higher luminous efficiency.

[0197] Application Example 1A

[0198] This application example provides an OLED device, such as Figure 1 As shown, Figure 1 The schematic diagram of the organic light-emitting device provided by the present invention includes a substrate 1, an anode 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, an electron transport layer 6, an electron injection layer 7, a cathode 8, and a capping layer 9 stacked in sequence.

[0199] The structure of the OLED blue light device is as follows: ITO (10nm) / compound 1:compound 2 (3:97 mass ratio) (5nm) / compound 3 (100nm) / compound 4 (5nm) / compound 5:compound 6 (97:3 mass ratio) (30nm) / / compound 7 (5nm) / compound 8:compound 9 (1:1 mass ratio) (30nm) / Mg:Ag (10:90 mass ratio, 10% by mass of Mg) (10nm) / M001 (70nm).

[0200] The fabrication steps of OLED devices are as follows:

[0201] 1) Cut the glass substrate into 50mm×50mm×0.7mm pieces, sonicate them in isopropanol and deionized water for 30 minutes each, and then clean them by exposing them to ozone for about 10 minutes to obtain substrate 1. Mount the resulting glass substrate with a 10nm indium tin oxide (ITO) anode onto a vacuum deposition apparatus;

[0202] 2) On the ITO anode layer 2, hole injection layer material compound 2 and p-doped material compound 1 are co-deposited by vacuum evaporation, with a doping ratio of 3% (mass ratio); the thickness is 5nm, and this layer serves as hole injection layer 3;

[0203] 3) Hole transport layer material compound 3 with a thickness of 100 nm is vacuum evaporated onto hole injection layer 3 to serve as first hole transport layer 4;

[0204] 4) Hole transport material compound 4 with a thickness of 5 nm is vacuum evaporated onto the first hole transport layer 4 to serve as the second hole transport layer 5;

[0205] 4) A light-emitting layer 6 is vacuum-deposited on the second hole transport layer 5, wherein compound 5 is used as the host material and compound 6 is used as the dopant material, with a doping ratio of 3% (mass ratio) and a thickness of 30nm.

[0206] 5) Electron transport material compound 7 with a thickness of 5 nm is vacuum-deposited on the light-emitting layer 6 as electron transport layer 7;

[0207] 6) Electron transport material compounds 8 and 9 are vacuum co-deposited on electron transport layer 7 with a doping mass ratio of 1:1 and a thickness of 30 nm, serving as electron injection layer 8;

[0208] 7) A magnesium-silver electrode is vacuum-deposited on the electron injection layer 8, wherein the Mg:Ag ratio is 1:9 and the thickness is 10 nm, serving as the cathode 9;

[0209] 8) Compound M001 with a thickness of 70 nm is vacuum-deposited on cathode 9 and used as capping layer 10.

[0210] The compound structure used in the OLED device is as follows:

[0211]

[0212] Application Example 1B

[0213] The preparation method is the same as in Application Example 1, but the following device structure is used:

[0214] The structure of the OLED green light device is as follows: ITO (10nm) / compound 1:compound 2 (3:97 mass ratio) (5nm) / compound 3 (140nm) / compound 4 (5nm) / CBP:Ir(ppy)3 (9:1 mass ratio) (40nm) / / compound 7 (5nm) / compound 8:compound 9 (1:1 mass ratio) (30nm) / Mg:Ag (10:90 mass ratio, 10% by mass of Mg) (10nm) / M001 (70nm).

[0215]

[0216] Application Example 1C

[0217] The preparation method is the same as in Application Example 1, but the following device structure is used:

[0218] The structure of the OLED red light device is as follows: ITO (10nm) / compound 1:compound 2 (3:97 mass ratio) (5nm) / compound 3 (190nm) / compound 4 (5nm) / CBP:Ir(piq)2(acac) (96:4 mass ratio) (40nm) / / compound 7 (5nm) / compound 8:compound 9 (1:1 mass ratio) (30nm) / Mg:Ag (10:90 mass ratio, 10% by mass of Mg) (10nm) / M001 (70nm).

[0219]

[0220] The difference between Application Examples 2(A, B, C)-72(A, B, C) and Example 1(A, B, C) is that compound M001 is replaced with the compounds shown in Table 3.

[0221] Comparative Example 1

[0222] The only difference between this comparative example and application example 1 is that the organic compound M001 in step (8) is replaced with an equal amount of the comparative compound ref 1; all other preparation steps are the same.

[0223]

[0224] Comparative Example 2

[0225] The only difference between this comparative example and Application Example 1A / Application Example 1B / Application Example 1C is that the organic compound M001 in step (8) is replaced with an equal amount of the comparative compound ref 2; all other preparation steps are the same.

[0226]

[0227] Comparative Example 3

[0228] The only difference between this comparative example and Application Example 1A / Application Example 1B / Application Example 1C is that the organic compound M001 in step (8) is replaced with an equal amount of the comparative compound ref 3; all other preparation steps are the same.

[0229]

[0230] Comparative Example 4

[0231] The only difference between this comparative example and Application Example 1A / Application Example 1B / Application Example 1C is that the organic compound M001 in step (8) is replaced with an equal amount of the comparative compound ref 4; all other preparation steps are the same.

[0232]

[0233] Performance evaluation of OLED devices:

[0234] The current of the OLED device under different voltages was measured using a Keithley 2365A digital nanovoltmeter, and then the current density of the OLED device under different voltages was obtained by dividing the current by the emitting area. The brightness and radiant energy flux density of the OLED device under different voltages were measured using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED device under different voltages, the operating driving voltage and current efficiency (Cd / A) at the same current density (10mA / cm2) were obtained. The lifetime (under the test condition of 50mA / cm2) was obtained by measuring the time it takes for the brightness of the OLED device to reach 95% of the initial brightness. Specific data are shown in Table 3.

[0235] Table 3. List of Device Performance Data

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242] As can be seen from the above embodiments and comparative examples, compared with the commercially available conventional capping layer material compound ref1, the compound provided by the present invention achieves higher luminous efficiency when applied to blue, green, and red light devices, with blue light luminous efficiency improved by 4%-7%, green light efficiency by 6%-14%, and red light efficiency by 5%-15%. This indicates that the compound of the present invention, when used as a capping layer material, has excellent light extraction capability and can effectively improve the luminous efficiency of OLED devices.

[0243] Compared to ref2, ref3, and ref4, M001, M029, M032, and M192 in this invention achieve an increase in refractive index in the blue, green, and red light regions simply by replacing carbon atoms with nitrogen atoms, thereby significantly improving the luminous efficiency of blue, green, and red light in OLED devices. Furthermore, the synthesis of nitrogen heterocycles is simple and inexpensive, making them suitable for mass production.

[0244] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A heterocyclic compound containing heteroatom-substituted fluorene, having the structure shown in Formula I-a or Formula I-b: in, Y is selected from O or S; Ar1 and Ar2 are identical and are selected from any of the following structures: 、 、 、 、 、 ； R1 is a hydrogen atom; The L1, L2, and L3 are independently selected from phenylene or naphthylene.

2. The heterocyclic compound according to claim 1, characterized in that, The L1, L2, and L3 are independently selected from any of the following structures: ； # indicates the connection position.

3. The heterocyclic compound according to claim 1, characterized in that, The heterocyclic compound has any of the following structures: 。 4. A display panel comprising an organic light-emitting device, the organic light-emitting device comprising an anode, a cathode and an organic thin layer located between the anode and the cathode, wherein a capping layer is covered on the cathode, the capping layer comprising any one or at least two combinations of heterocyclic compounds as described in any one of claims 1 to 3.

5. A display device comprising the display panel of claim 4.

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